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Assessing exposure to airborne fungi and bacteria in the horse-riders environment: A pilot study
This study aimed to determine the optimal conditions for horse care, ensuring their physical and psychological welfare by analysing housing, nutrition, medical care, physical activity, and socialisation. The study examined the horse care conditions at farms and equestrian clubs in the Kyiv region (Ukraine), including “Aliur”, “Grand Prix”, “Kniazhyi Dvir”, “Impuls”, and “Olimp”. The theoretical analysis described horse care conditions, the size and state of the facilities, feed quality, medical care, and aspects of physical activity and socialisation. The study’s main findings indicate that all the analysed establishments provide a high level of comfort for horses, a crucial factor for their care and wellbeing. However, it is important to note that various approaches to horse care revealed unique features and advantages. For instance, the farm “Aliur” demonstrated an effective combination of high-quality housing conditions, including spacious stables with proper lighting and ventilation, balanced nutrition tailored to the individual needs of each animal, regular medical care ensuring timely prevention and treatment, and socialisation that fosters the emotional development of the horses. At the same time, the equestrian farm “Grand Prix” stands out for its high standards of sports care, which include specialised training and preparation of horses for competitions, ensuring their competitiveness in the sporting arena. The farms “Impuls” and “Olimp” distinguish themselves by implementing modern ventilation systems that improve air quality in the stables, as well as by providing high-quality training facilities that meet international standards, allowing not only the maintenance of horses’ physical fitness but also ensuring their overall health and welfare. The analysis showed that the introduction of new monitoring technologies, the individualisation of feeding approaches, and social programmes could further enhance horse welfare. The findings highlight the importance of a comprehensive approach to horse care in ensuring their physical and psychological well-being, which can be useful for practical recommendations in the equine industry
The fungal kingdom comprises ubiquitous forms of life with 1.5 billion years, mostly phytopathogenic and commensals for humans and animals. However, in the presence of immune disorders, fungi may cause disease by intoxicating, infecting or sensitizing with allergy. Species from the genera Alternaria, Aspergillus and Malassezia, as well as dermatophytes from the genera Microsporum, Trichophyton and Epidermophyton, are the most commonly implicated in veterinary medicine. Alternaria and Malassezia stand as the most commonly associated with either allergy or infection in animals, immediately followed by Aspergillus, while dermatophytes are usually associated with the ringworm skin infection. By aiming at the relevance of fungi in veterinary allergy it was concluded that further research is still needed, especially in the veterinary field.
Keeping horses in good condition requires providing them with living conditions that meet welfare requirements. These animals should be accommodated with suitable space, access to high nutritional fodder and water, and a suitable microclimate in their shelters. When it comes to the environment in the stables, a serious problem is created by particulate matter (PM), which consists of bacteria. PM concentration may be responsible for developing multiple lower respiratory tract diseases in horses, including allergies and recurrent airway obstruction (RAO). In turn, these ailments may lead to decreasing equine physical and mental fitness. Additionally, people who spend time in the stables are exposed to the same harmful factors. The study was conducted in Udórz Stud Farm located in the southern region of Poland. The study was carried out in 2 different types of stables: 3 runners (a type of stable where horses are housed together and occasionally linked up, e.g., for feeding or grooming) and 2 box stables. The research continued for 2 years and the samples were collected in each season. The bioaerosol samples were collected using a six-stage Andersen-Graseby cascade impactor to assess size distribution and concentrations of airborne bacteria. PM concentration was analyzed using the DustTrak™ II Aerosol Monitor 8530, while microclimate parameters were measured using the Kestrel 5000 Weather Meter. There are almost no studies concerning size distribution of airborne bacteria, individual PM fractions, and the impact of everyday handling on the changes in the bioaerosol and PM concentration. This preliminary study provided basic information on this subject. We have revealed a strong correlation between high PM and bacterial aerosol concentrations. Higher contamination levels were recorded in runners, as compared to box stables. The highest bacterial aerosol level was detected in the spring. The analysis of the fractions of the bacterial aerosol in the stables indicated the highest share of ultra-fine fraction (0.65–2.1 µm), while respirable fraction (below 4.7 µm) exceeded 75%. It was established that the concentration of the bacterial aerosol inside the stables was many times higher than outside. It depended significantly on everyday activities undertaken in the stables, like feeding or cleaning. Taking the above into account, a different cleaning system should be developed (a wet cleaning system, with the use of water) and excrement should be removed more frequently.
In many complaint cases regarding bad indoor environments, there is no evidence of visible fungal growth. To determine if the problems are fungi-related, dust sampling is the method of choice among building surveyors. However, there is a need to differentiate between species belonging to a normal, dry indoor environment and species belonging to a damp building envelope. The purposes of this pilot study were to examine which fungal species are present in problem-free Danish homes and to evaluate different detection and identification methods. Analyses showed that the fungal diversity outside was different from the diversity inside and that the composition of fungal species growing indoors was different compared to those found as spores, both indoors and outdoors. Common for most homes were Pseudopithomyceschartarum, Cladosporiumallicinum and Alternaria sect. Infectoriae together with Botrytis spp., Penicilliumdigitatum and Pen. glabrum. The results show that ITS sequencing of dust samples is adequate if supported by thorough building inspections and that food products play as large a role in the composition of the baseline spora as the outdoor air and surrounding vegetation. This pilot study provides a list of baseline fungal species found in Danish homes with a good indoor environment.
High-throughput DNA sequencing (HTS) has changed our understanding of the microbial composition present in a wide range of environments. Applying HTS methods to air samples from different environments allows the identification and quantification (relative abundance) of the microorganisms present and gives a better understanding of human exposure to indoor and outdoor bioaerosols. To make full use of the avalanche of information made available by these sequences, repeated measurements must be taken, community composition described, error estimates made, correlations of microbiota with covariates (variables) must be examined, and increasingly sophisticated statistical tests must be conducted, all by using bioinformatics tools. Knowing which analysis to conduct and which tools to apply remains confusing for bioaerosol scientists, as a litany of tools and data resources are now available for characterizing microbial communities. The goal of this review paper is to offer a guided tour through the bioinformatics tools that are useful in studying the microbial ecology of bioaerosols. This work explains microbial ecology features like alpha and beta diversity, multivariate analyses, differential abundances, taxonomic analyses, visualization tools and statistical tests using bioinformatics tools for bioaerosol scientists new to the field. It illustrates and promotes the use of selected bioinformatic tools in the study of bioaerosols and serves as a good source for learning the "dos and don'ts" involved in conducting a precise microbial ecology study.
True fungi (Fungi) and fungus-like organisms (e.g. Mycetozoa, Oomycota) constitute the second largest group of organisms based on global richness estimates, with around 3 million predicted species. Compared to plants and animals, fungi have simple body plans with often morphologically and ecologically obscure structures. This poses challenges for accurate and precise identifications. Here we provide a conceptual framework for the identification of fungi, encouraging the approach of integrative (polyphasic) taxonomy for species delimitation, i.e. the combination of genealogy (phylogeny), phenotype (including autecology), and reproductive biology (when feasible). This allows objective evaluation of diagnostic characters, either phenotypic or molecular or both. Verification of identifications is crucial but often neglected. Because of clade-specific evolutionary histories, there is currently no single tool for the identification of fungi, although DNA barcoding using the internal transcribed spacer (ITS) remains a first diagnosis, particularly in metabarcoding studies. Secondary DNA barcodes are increasingly implemented for groups where ITS does not provide sufficient precision. Issues of pairwise sequence similarity-based identifications and OTU clustering are discussed, and multiple sequence alignment-based phylogenetic approaches with subsequent verification are recommended as more accurate alternatives. In metabarcoding approaches, the trade-off between speed and accuracy and precision of molecular identifications must be carefully considered. Intragenomic variation of the ITS and other barcoding markers should be properly documented, as phylotype diversity is not necessarily a proxy of species richness. Important strategies to improve molecular identification of fungi are: (1) broadly document intraspecific and intragenomic variation of barcoding markers; (2) substantially expand sequence repositories, focusing on undersampled clades and missing taxa; (3) improve curation of sequence labels in primary repositories and substantially increase the number of sequences based on verified material; (4) link sequence data to digital information of voucher specimens including imagery. In parallel, technological improvements to genome sequencing offer promising alternatives to DNA barcoding in the future. Despite the prevalence of DNA-based fungal taxonomy, phenotype-based approaches remain an important strategy to catalog the global diversity of fungi and establish initial species hypotheses.
The Eurotiales is a relatively large order of Ascomycetes with members frequently having positive and negative impact on human activities. Species within this order gain attention from various research fields such as food, indoor and medical mycology and biotechnology. In this article we give an overview of families and genera present in the Eurotiales and introduce an updated subgeneric, sectional and series classification for Aspergillus and Penicillium. Finally, a comprehensive list of accepted species in the Eurotiales is given. The classification of the Eurotiales at family and genus level is traditionally based on phenotypic characters, and this classification has since been challenged using sequence-based approaches. Here, we re-evaluated the relationships between families and genera of the Eurotiales using a nine-gene sequence dataset. Based on this analysis, the new family Penicillaginaceae is introduced and four known families are accepted: Aspergillaceae, Elaphomycetaceae, Thermoascaceae and Trichocomaceae. The Eurotiales includes 28 genera: 15 genera are accommodated in the Aspergillaceae (Aspergillago, Aspergillus, Evansstolkia, Hamigera, Leiothecium, Monascus, Penicilliopsis, Penicillium, Phialomyces, Pseudohamigera, Pseudopenicillium, Sclerocleista, Warcupiella, Xerochrysium and Xeromyces), eight in the Trichocomaceae (Acidotalaromyces, Ascospirella, Dendrosphaera, Rasamsonia, Sagenomella, Talaromyces, Thermomyces, Trichocoma), two in the Thermoascaceae (Paecilomyces, Thermoascus) and one in the Penicillaginaceae (Penicillago). The classification of the Elaphomycetaceae was not part of this study, but according to literature two genera are present in this family (Elaphomyces and Pseudotulostoma). The use of an infrageneric classification system has a long tradition in Aspergillus and Penicillium. Most recent taxonomic studies focused on the sectional level, resulting in a well-established sectional classification in these genera. In contrast, a series classification in Aspergillus and Penicillium is often outdated or lacking, but is still relevant, e.g., the allocation of a species to a series can be highly predictive in what functional characters the species might have and might be useful when using a phenotype-based identification. The majority of the series in Aspergillus and Penicillium are invalidly described and here we introduce a new series classification. Using a phylogenetic approach, often supported by phenotypic, physiologic and/or extrolite data, Aspergillus is subdivided in six subgenera, 27 sections (five new) and 75 series (73 new, one new combination), and Penicillium in two subgenera, 32 sections (seven new) and 89 series (57 new, six new combinations). Correct identification of species belonging to the Eurotiales is difficult, but crucial, as this the species name is the linking pin to information. Lists of accepted species are a helpful aid for researchers to obtain a correct identification using the current taxonomic schemes. In the most recent list from 2014, 339 Aspergillus, 354 Penicillium and 88 Talaromyces species were accepted. These numbers increased significantly, and the current list includes 446 Aspergillus (32 % increase), 483 Penicillium (36 % increase) and 171 Talaromyces (94 % increase) species, showing the large diversity and high interest in these genera. We expanded this list with all genera and species belonging to the Eurotiales (except those belonging to Elaphomycetaceae). The list includes 1 187 species, distributed over 27 genera, and contains MycoBank numbers, collection numbers of type and ex-type cultures, subgenus, section and series classification data, information on the mode of reproduction, and GenBank accession numbers of ITS, beta-tubulin (BenA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) gene sequences.
Dothideomycetes is the largest class of kingdom Fungi and comprises an incredible diversity of lifestyles, many of which have evolved multiple times. Plant pathogens represent a major ecological niche of the class Dothideomycetes and they are known to infect most major food crops and feedstocks for biomass and biofuel production. Studying the ecology and evolution of Dothideomycetes has significant implications for our fundamental understanding of fungal evolution, their adaptation to stress and host specificity, and practical implications with regard to the effects of climate change and on the food, feed, and livestock elements of the agro-economy. In this study, we present the first large-scale, whole-genome comparison of 101 Dothideomycetes introducing 56 newly sequenced species. The availability of whole-genome data produced a high-confidence phylogeny leading to reclassification of 25 organisms, provided a clearer picture of the relationships among the various families, and indicated that plant pathogenicity evolved multiple times within this class. We also identified gene family expansions and contractions across the Dothideomycetes phylogeny linked to ecological niches providing insights into genome evolution and adaptation across this group. Using machine-learning methods we classified fungi into lifestyle classes with >95% accuracy and identified a small number of gene families that positively correlated with these distinctions. This can become a valuable tool for genome-based prediction of species lifestyle, especially for rarely seen and poorly studied species.
Equine asthma syndrome (EAS) is a common problem that affects horses of any age. Severe EAS is reported to affect 10–20% of adult horses in the northern hemisphere, while mild/moderate EAS is reported to affect 60–100% of adult horses, depending on the population and geographic region. For both severe and mild/moderate EAS, the presence of lower airway inflammation is attributed to airborne “triggers” such as dust, mold, and bacterial components that horses encounter in hay and stable-environments; and treatment recommendations for horses with EAS often include full-time pasture turnout. The caveat to this recommendation is horses with summer-pasture associated EAS (SP-EAS), who experience allergic lower airway inflammation when exposed to summer pasture. The prevalence of EAS in horses on pasture that do not have SP-EAS has not been reported. The purpose of this study was to use bronchoalveolar lavage (BAL) cytology to determine the prevalence of EAS in a herd of pastured, adult research horses with no history of respiratory disease. The horses were members of a teaching animal herd housed on pasture in the southeastern United States and fed round-bale Bermuda-grass hay. BAL fluid (BALF) cytology was analyzed in both summer (May–August 2017) and winter (November 2017–February 2018). Similar to previous reports, the prevalence of severe EAS in our study population was 10% in summer and 4.3% in winter. The prevalence of mild/moderate EAS was 60% in summer and 87% in winter. The high prevalence of mild/moderate EAS in this population was unexpected, given the 24-h, year-round pasture environment and the lack of history of respiratory disease. Additionally, 61.1% of horses with both summer and winter data had a different BALF cytology profile between the two seasons. To the authors' knowledge, this is the first study to use BAL cytology to diagnose, and monitor changes in, EAS phenotype in pastured adult horses. These results help to inform discussions regarding prevalence of EAS in pastured, adult horses in the southeastern region of North America.
Background
Fungi contribute to the inflammatory response of lungs in horses with recurrent airway obstruction and in some forms of asthma in humans. The role of fungi in inflammatory airway disease (IAD) has not been assessed.
Objectives
Evaluate the prevalence of fungi in the respiratory samples of horses diagnosed with IAD, describe clinical signs associated with the presence of fungi in respiratory samples, and assess the risk factors associated with IAD and with the presence of fungi in the airways.
Animals
Seven‐hundred thirty‐one active horses referred to a specialized ambulatory practice for signs of respiratory disease or poor performance.
Methods
A prospective observational study was performed, collecting clinical data, environmental conditions, and results of a tracheal wash (TW; cytology, fungal culture, and bacterial culture), and bronchoalveolar lavage (cytology).
Results
A positive fungal culture was obtained in 55% (402/731) of horses. Horses with fungal elements observed on the TW cytology had 2 times greater chance of having IAD than horses without fungi (odds ratio [OR] = 2.1; 95% CI 1.08‐3.33; P = .0003). Risks of being diagnosed with IAD and likelihood of fungi in TW were higher when horses were bedded on straw (OR = 2.0; 95% CI 1.2‐3.2 and OR = 1.9; 95% CI 1.3‐2.6, respectively) or fed dry hay (OR = 2.7; 95% CI 1.7‐4.4 and OR = 2.6; 95% CI 1.6‐3.4, respectively).
Conclusions and Clinical Importance
Horses inhaling aerosolized fungal particles are at a significantly higher risk of developing IAD. The type of bedding and forage represent significant risk factors for IAD and fungal contamination of equine airways.
The term “equine asthma” has been proposed as a unifying descriptor of inflammatory airway disease (IAD), recurrent airway obstruction (RAO), and summer pasture‐associated obstructive airway disease. Whilst the term will increase comprehensibility for both the lay and scientific communities, its biologic relevance must be compared and contrasted to asthma in human medicine, recognizing the limited availability of peer‐reviewed equine‐derived data, which are largely restricted to clinical signs, measures of airway obstruction and inflammation and response to therapy. Such limitations constrain meaningful comparisons with human asthma phenotypes. Suggested minimum inclusion criteria supporting the term asthma, as well as similarities and differences between IAD, RAO, and multiple human asthma phenotypes are discussed. Furthermore, differences between phenotype and severity are described, and typical features for equine asthma subcategories are proposed. Based on shared features, we conclude that mild/moderate (IAD) and severe (RAO) equine asthma are biologically appropriate models for both allergic and non‐allergic human asthma, with RAO (severe equine asthma) also being an appropriate model for late‐onset asthma. With the development of new biologic treatments in humans and the application of more targeted therapeutic approaches in the horse, it would appear appropriate to further investigate the allergic (Th‐2) and non‐allergic (non‐Th‐2) phenotypes of equine asthma. Further research is required to more fully determine the potential clinical utility of phenotype classification.
The high-altitude atmosphere is a harsh environment with extremely low temperatures, low pressure, and high UV irradiation. For this reason, it has been proposed as an analogue for Mars, presenting deleterious factors similar to those on the surface of that planet. We evaluated the survival of extremophilic UV-resistant yeasts isolated from a high-elevation area in the Atacama Desert under stratospheric conditions. As biological controls, intrinsically resistant Bacillus subtilis spores were used. Experiments were performed in two independent stratospheric balloon flights and with an environmental simulation chamber. The three following different conditions were evaluated: (i) desiccation, (ii) desiccation plus exposure to stratospheric low pressure and temperature, and (3) desiccation plus exposure to the full stratospheric environment (UV, low pressure, and temperature). Two strains, Naganishia (Cryptococcus) friedmannii 16LV2 and Exophiala sp. strain 15LV1, survived full exposures to the stratosphere in larger numbers than did B. subtilis spores. Holtermanniella watticus (also known as Holtermanniella wattica) 16LV1, however, suffered a substantial loss in viability upon desiccation and did not survive the stratospheric UV exposure. The remarkable resilience of N. friedmannii and Exophiala sp. 15LV1 under the extreme Mars-like conditions of the stratosphere confirms its potential as a eukaryotic model for astrobiology. Additionally, our results with N. friedmannii strengthen the recent hypothesis that yeasts belonging to the Naganishia genus are fit for aerial dispersion, which might account for the observed abundance of this species in high-elevation soils.
Actinobacteria endophytes of medicinal plants may play an essential role in producing a variety of critical bioactive compounds. However, the possible contribution of such actinobacteria to the pharmacological properties of traditional herbal remedies remains mostly unknown. For example, the diversity and attributes of actinobacteria endophytes in Ficus deltoidea, a small tree species that has long been used to treat diseases such as cancer, diabetes, and cardiovascular illnesses, have not been explored. Here, the actinobacteria endophyte community structure in F. deltoidea was investigated using both culture-dependent and metagenomics approaches. Based on morphological characteristics and 16S rRNA gene analysis, the dominant culturable actinobacteria isolates exhibited a close relationship with Streptomyces. The metagenomic technique using PCR-DGGE analysis of the 16S rRNA gene showed the presence of 11 OTUs in F. deltoidea tissue. Whereas the dominant culturable actinobacteria endophytes in F. deltoidea was Streptomyces, the metagenomic approach showed non-Streptomyces, particularly Rhodococccus and Verrucosispora, to be also important. Thus, results from both culture-dependent and metagenomic approaches provided useful indicators on the diversity and community structure of actinobacteria endophytes in F. deltoidea. © 2018, Society for Indonesian Biodiversity. All rights reserved.
The aim of this study was to assess the microbiological quality of air in three horse riding centers differing in the horse keeping systems. The air samples were collected in one facility with free-range horse keeping system and two with box stalls of different sizes. The samples were collected over a period of 3 years (2015–2017), four times per year (spring, summer, autumn, winter) to assess the effect of seasonal changes. The prevalence of aerobic mesophilic bacteria, mold fungi, actinomycetes, Staphylococcus spp., and Escherichia coli was determined by the air collision method on Petri dishes with appropriate microbiological media. At the same time, air temperature, relative humidity, and particulate matter concentration (PM10, PM2.5) were measured. It was found that the horse keeping system affects the occurrence of the examined airborne microorganisms. Over the 3-year period of study, higher temperature and humidity, as well as particulate matter concentration—which notoriously exceeded limit values—were observed in the facilities with the box-stall system. The air sampled from the largest horse riding center, with the largest number of horses and the box-stall system of horse keeping, was also characterized by the heaviest microbiological contamination. Among others, bacteria from the following genera: Staphylococcus spp., Streptococcus spp., Bacillus spp., and E. coli and fungi from the genera Aspergillus, Fusarium, Mucor, Rhizopus, Penicillium, Trichothecium, Cladosporium, and Alternaria were identified in the analyzed samples.
Guttural pouch mycosis (GPM) is a rare but potentially life-threatening condition in horses. GPM is caused by a fungal invasion into the mucosal lining of the guttural pouches and, frequently, the associated neurovascular structures. Although several species of fungi have been associated with this disease, Aspergillus spp. appear to be the most common isolated from the guttural pouches. However, it remains unclear which are the predisposing factors leading to the development of the infection. The objectives of the present study were to experimentally reproduce an infection by Aspergillus fumigatus and to follow the natural evolution of the mycosis. Eight guttural pouches from four horses were experimentally infected by endoscopy-guided intrapouch inoculation of A. fumigatus culture. Horses were monitored for clinical signs and development of fungal plaques through endoscopic examination. Mycotic lesions were observed in all the horses and a spontaneous regression was observed within 15–28 days. No development of clinical signs was noticed. In conclusion, we were able to induce the development of mycotic lesions and to observe a natural regression of these lesions without clinical signs.
Assigning ecological roles to bacterial taxa remains imperative to understanding how microbial communities will respond to changing environmental conditions. Here we analyze the genus Curtobacterium, as it was found to be the most abundant taxon in a leaf litter community in southern California. Traditional characterization of this taxon predominantly associates it as the causal pathogen in the agricultural crops of dry beans. Therefore, we sought to investigate whether the abundance of this genus was because of its role as a plant pathogen or another ecological role. By collating >24,000 16S rRNA sequences with 120 genomes across the Microbacteriaceae family, we show that Curtobacterium has a global distribution with a predominant presence in soil ecosystems. Moreover, this genus harbors a high diversity of genomic potential for the degradation of carbohydrates, specifically with regards to structural polysaccharides. We conclude that Curtobacterium may be responsible for the degradation of organic matter within litter communities.
Fungi of the genus Aspergillus are widespread in the environment. Some Aspergillus species, most commonly Aspergillus fumigatus, may lead to a variety of allergic reactions and life-threatening systemic infections in humans. Invasive aspergillosis occurs primarily in patients with severe immunodeficiency, and has dramatically increased in recent years. There are several factors at play that contribute to aspergillosis, including both fungus and host-related factors such as strain virulence and host pulmonary structure/immune status, respectively. The environmental tenacity of Aspergilllus, its dominance in diverse microbial communities/habitats, and its ability to navigate the ecophysiological and biophysical challenges of host infection are attributable, in large part, to a robust stress-tolerance biology and exceptional capacity to generate cell-available energy. Aspects of its stress metabolism, ecology, interactions with diverse animal hosts, clinical presentations and treatment regimens have been well-studied over the past years. Here, we synthesize these findings in relation to the way in which some Aspergillus species have become successful opportunistic pathogens of human- and other animal hosts. We focus on the biophysical capabilities of Aspergillus pathogens, key aspects of their ecophysiology and the flexibility to undergo a sexual cycle or form cryptic species. Additionally, recent advances in diagnosis of the disease are discussed as well as implications in relation to questions that have yet to be resolved.
The aim of the study was to evaluate selected physical and microbiological air parameters. The analysis was conducted during the spring, summer, fall and winter in a box-stall stable with Wielkopolski horses. The physical air parameters were measured according to generally established methods used in livestock science. The air was evaluated for microbial contamination by the impaction method; 12 samplings were carried out using a SAS 100 sampler located in three sampling sites of the stable: the initial, middle, and end part of the building. The numbers of the following microbes were determined in the analyzed air: total bacteria, Enterobacteriaceae cells, strepto-cocci, mannitol positive staphylococci, hemolytic bacteria, actinomycetes and total molds and yeast-like fungi. Measurements of temperature and humidity parameters showed that the average air temperature in the stables was lowest in the winter, 8.2°C with humidity 76.2%, whereas the highest average air temperatures, which averaged 21.2°C with the lowest relative humidity of 60.2%, were recorded in the summer. The other air physical parameters corresponded to the minimum requirements for horses. Microbiological analyses of air samples revealed the presence of bacteria belonging to the Enterobacteriaceae family, staphylococci, streptococci, as well as fungi that can adversely affect the health of horses and people in the stables. We the found air microbial contamination above the standard level, and it depended on microclimate conditions and the season.
Mucormycosis due to
Lichtheimia ramosa
is an infrequent opportunistic infection that can potentially be angioinvasive when affecting inmunocompromised hosts. We present a fatal case of mucormycosis, affecting a 56-year-old male with diabetes mellitus and siderosis, initially admitted to our hospital due to an H1N1 infection. The subject’s clinical condition worsened and he finally died because of a necrotizing bilateral pneumonia with disseminated mycotic thromboses due to
Lichtheimia ramosa
, which is an emerging Mucoralean fungus. This is an infrequent case because of the extent to which it affected a subject without overt immunocompromise. This case underlines the importance of an early premortem diagnosis and treatment in order to prevent rapid progression of this disease, as well as the need of considering mucormycosis when facing subjects with multiple emboli and fever unresponsive to usual antimicrobials.
Fungi are ubiquitous microorganisms that are present in outdoor and indoor environments. Previous research has found relationships between environmental fungal exposures and human health effects. We reviewed recent articles focused on fungal exposure and dampness as risk factors for respiratory disease development, symptoms, and hypersensitivity. In particular, we reviewed the evidence suggesting that early exposure to dampness or fungi is associated with the development of asthma and increased asthma morbidity. Although outdoor exposure to high concentrations of spores can cause health effects such as asthma attacks in association with thunderstorms, most people appear to be relatively unaffected unless they are sensitized to specific genera. Indoor exposure and dampness, however, appears to be associated with an increased risk of developing asthma in young children and asthma morbidity in individuals who have asthma. These are important issues because they provide a rationale for interventions that might be considered for homes and buildings in which there is increased fungal exposure. In addition to rhinitis and asthma, fungus exposure is associated with a number of other illnesses including allergic bronchopulmonary mycoses, allergic fungal sinusitis, and hypersensitivity pneumonitis. Additional research is necessary to establish causality and evaluate interventions for fungal- and dampness-related health effects.
The aim of this study was to assess the relationship between living conditions (microclimate, aerial contaminations, box dimension, access to the paddock/pasture) of horses kept in 3 stables and physiological indicators (protein and its fractions in serum, haptoglobin). The study was carried out for 4 months during autumn and winter in 3 stables. Blood samples were collected from 10 clinically healthy adult horses from each stable (30 in total) in 4 terms every 4 weeks. Environmental conditions were evaluated according to zoohygiene methodology and current law regulation. In the blood serum, the analyzed parameters were: total protein (g/L) with the biuret test, the contribution of individual serum protein fractions (%) (albumin and alpha 1-, alpha 2-, beta- and gamma-globulin) set to serum protein electrophoresis on agarose gels in an SAS-MX electrophoresis chamber; haptoglobin concentration (g/L) immunoturbidimetric test. Living conditions meeting the requirements of welfare were provided in stable 3 in terms of both microclimatic parameters as well as the dimensions of the boxes and access to paddock and pasture. Slightly worse conditions were recorded in stable 2, while stable 1 was characterized by not only the worst microclimatic parameters, but also the surface of the boxes was too small. The different living conditions of horses in different stables were reflected in the diverse values of the blood indicators. Although the obtained ratios of protein indicators corresponded to the values of normal adult healthy horses, it was demonstrated that in the serum of horses in stables 1 and 2, as compared to the stable 3, a significantly lower fraction of albumin and higher alpha 2-globulin and a higher concentration of Hp was found - suggesting the effect of different living conditions on organism homeostasis indicators. It may be stated that living conditions significantly influence the physiological condition of the horse.
The Kingdom Fungi contains diverse eukaryotic organisms including yeasts, molds, mushrooms, bracket fungi, plant rusts, smuts, and puffballs. Fungi have a complex metabolism that differs from animals and plants. They secrete enzymes into their surroundings and absorb the breakdown products of enzyme action. Some of these enzymes are well-known allergens. The phylogenetic relationships among fungi were unclear until recently because classification was based on the sexual state morphology. Fungi lacking an obvious sexual stage were assigned to the artificial, now-obsolete category, "Deuteromycetes" or "Fungi Imperfecti." During the last 20 years, DNA sequencing has resolved 8 fungal phyla, 3 of which contain most genera associated with important aeroallergens: Zygomycota, Ascomycota, and Basidiomycota. Advances in fungal classification have required name changes for some familiar taxa. Because of regulatory constraints, many fungal allergen extracts retain obsolete names. A major benefit from this reorganization is that specific immunoglobulin E (IgE) levels in individuals sensitized to fungi appear to closely match fungal phylogenetic relationships. This close relationship between molecular fungal systematics and IgE sensitization provides an opportunity to systematically look at cross-reactivity and permits representatives from each taxon to serve as a proxy for IgE to the group.
Objectives:
Air quality in the stables is characterized by elevated level of dust and aeroallergens which are supposed to directly cause or exacerbate several respiratory disorders. The most often recognized problem is recurrent airway obstruction (RAO), previously known as chronic obstructive pulmonary disease (COPD). There is some indication that aeroallergens (among them endotoxins) may also cause inflammation in human airways and may exceed safe levels in stables. Monitoring studies have covered mainly the determination of the concentration of respirable particles and of culturable fungi and their toxins. However, these particles do not only directly affect the respiratory system, but might act as a carrier conveying toxic contaminants and biological agents such as bacteria. In a typical, 20-horse Hungarian stable, microbial community of respirable fraction of resuspended dust has been characterized to reveal if these particles convey hazardous pathogenic bacteria, posing risk to either horses or staff.
Material and methods:
Resuspended dust was sampled using a mobile instrument. The instrument contains a PARTISOL-FRM model 2000 sampler that was operated at a flow rate of 16.7 l/min and a cyclone separator which collected the particulate matter with an aerodynamic size between 1 μm and 10 μm (PM1-10) fraction. Microbial taxa were identified by culture-independent next generation sequencing (NGS) of variable 16S ribosomal ribonucleic acid (rRNA) gene regions.
Results:
In total, 1491 different taxa were identified, of them 384 were identified to species level, 961 to genus level. The sample was dominated by common ubiquitous soil and organic material-dwelling taxa.
Conclusions:
Pathogens occurred at low abundance, and were represented by mostly facultative human pathogens, with the prevalence of Staphylococcus species.
Inhalant exposure to airborne irritants commonly encountered in horse stables is implicated in the pathogenesis of inflammatory airway disease (IAD) and recurrent airway obstruction (RAO), non-infectious, inflammatory pulmonary disorders that impact the health and performance of horses across all equine disciplines. IAD and RAO have overlapping clinical, cytological, and functional manifestations of the pulmonary response to organic dust and noxious gases encountered in the barn environment. Study of these diseases has provided important but incomplete understanding of the effect of air quality upon the respiratory health of horses. In this review, the principles of particulate exposure assessment, including health-related aerosol size fractions and size-selective sampling, the factors influencing air quality in equine environments, and the effect of air quality on the equine respiratory tract are discussed. The objective of this review is to provide the reader with a summary of the most common chronic inflammatory airway diseases in the horse and the principles of air sampling that are essential to the planning, interpretation, and assessment of equine respiratory health-related exposure studies.
The aim of the study was to determine the level of air bacteria and fungi in the horse stable and the emission of microorganisms to the external environment during different seasons of the year. The predominating fungi in the stable and outside were also identified. These results demonstrate that both in the stables and outdoors, the number of microorganisms was the highest in the summer. This tendency was especially noticeable in the case of the concentrations of fungi outside the building, when the average value was significantly higher (P<0.01) than in other seasons. No statistically significant differences in the concentrations of airborne microorganisms at different distances from the stable were observed. Penicillium sp., Fusarium sp., and yeast predominated inside and outside the stable.
Among diseases of horses caused by fungi (=mycoses), dermatophytosis, cryptococcosis and aspergillosis are of particular concern, due their worldwide diffusion and, for some of them, zoonotic potential. Conversely, other mycoses such as subcutaneous (i.e., pythiosis and mycetoma) or deep mycoses (i.e., blastomycosis and coccidioidomycosis) are rare, and/or limited to restricted geographical areas. Generally, subcutaneous and deep mycoses are chronic and progressive diseases; clinical signs include extensive, painful lesions (not pathognomonic), which resemble to other microbial infections. In all cases, early diagnosis is crucial in order to achieve a favorable prognosis. Knowledge of the epidemiology, clinical signs, and diagnosis of fungal diseases is essential for the establishment of effective therapeutic strategies. This article reviews the clinical manifestations, diagnosis and therapeutic protocols of equine fungal infections as a support to early diagnosis and application of targeted therapeutic and control strategies.
Biogenic aerosols play important roles in atmospheric chemistry physics, the biosphere, climate, and public health. Here, we show that fungi which actively discharge their spores with liquids into the air, in particular actively wet spore discharging Ascomycota (AAM) and actively wet spore discharging Basidiomycota (ABM), are a major source of primary biogenic aerosol particles and components. We present the first estimates for the global average emission rates of fungal spores.
Measurement results and budget calculations based on investigations in Amazonia (Balbina, Brazil, July 2001) indicate that the spores of AAM and ABM may account for a large proportion of coarse particulate matter in tropical rainforest regions during the wet season (0.7–2.3 μg m^−3). For the particle diameter range of 1–10 μm, the estimated proportions are ~25% during day-time, ~45% at night, and ~35% on average. For the sugar alcohol mannitol, the budget calculations indicate that it is suitable for use as a molecular tracer for actively wet discharged basidiospores (ABS). ABM emissions seem to account for most of the atmospheric abundance of mannitol (10–68 ng m^−3), and can explain the observed diurnal cycle (higher abundance at night). ABM emissions of hexose carbohydrates might also account for a significant proportion of glucose and fructose in air particulate matter (7–49 ng m^−3), but the literature-derived ratios are not consistent with the observed diurnal cycle (lower abundance at night). AAM emissions appear to account for a large proportion of potassium in air particulate matter over tropical rainforest regions during the wet season (17–43 ng m^−3), and they can also explain the observed diurnal cycle (higher abundance at night). The results of our investigations and budget calculations for tropical rainforest aerosols are consistent with measurements performed at other locations.
Based on the average abundance of mannitol reported for extratropical continental boundary layer air (~25 ng m^−3), we have also calculated a value of ~17 Tg yr^−1 as a first estimate for the global average emission rate of ABS over land surfaces, which is consistent with the typically observed concentrations of ABS (~10³–10^4 m^−3; ~0.1–1 μg m^−3). The global average atmospheric abundance and emission rate of total fungal spores, including wet and dry discharged species, are estimated to be higher by a factor of about three, i.e. 1 μg m^−3 and ~50 Tg yr^−1. Comparisons with estimated rates of emission and formation of other major types of organic aerosol (~47 Tg yr^−1 of anthropogenic primary organic aerosol; 12–70 Tg yr^−1 of secondary organic aerosol) indicate that emissions from fungi should be taken into account as a significant global source of organic aerosol. The effects of fungal spores and related chemical components might be particularly important in tropical regions, where both physicochemical processes in the atmosphere and biological activity at the Earth's surface are particularly intense, and where the abundance of fungal spores and related chemical compounds are typically higher than in extratropical regions.
Workers in horse stables are likely exposed to high levels of organic dust. Organic dusts play a role in increased risk of inflammatory reactions and are associated with respiratory diseases. The aim of this study was to investigate dust, endotoxin, beta(1-->3)-glucan, and culturable microorganisms exposure levels in horse stables.
Ambient (n = 38) and personal (n = 42) inhalable dust samples were collected using PAS-6 sampling heads. As a special measurement, we included sampling near the horses' heads. Samples were analyzed for endotoxin and beta(1-->3)-glucan by Limulus amebocyte lysate assay and an inhibition enzyme immunoassay, respectively. Culturable bacteria and fungi were collected with an Anderson impactor.
Geometric means (GMs) of personal exposure to dust, endotoxin, and beta(1-->3)-glucan were 1.4 mg m(-3) (range 0.2-9.5), 608 EU m(-3) (20-9846), and 9.5 microg m(-3) (0.4-631 microg m(-3)), respectively. Exposure levels in the morning shift were higher compared to other shifts. The GMs (ranges) of culturable bacteria and fungi were 3.1 x 10(3) colony-forming unit (CFU) m(-3) (6.7 x 10 to 1.9 x 10(4)) and 1.9 x 10(3) CFU m(-3) (7.4 x 10 to 2.4 x 10(4)), respectively. Variance components for endotoxin and beta(1-->3)-glucan were considerably higher than for dust. Based on dummy variable in a mixed regression analysis, the predominant task explaining exposure levels of dust, endotoxin, and beta(1-->3)-glucan was sweeping the floor. For beta(1-->3)-glucan, feeding the horse was also an important determinant.
Dust, endotoxin, and beta(1-->3)-glucan exposure are considerable in horse stables. Bacterial and fungal exposure levels were moderate. Endotoxin exposures were above the Dutch proposed standard limits, suggesting workers in horse stables to be at risk of adverse health effects.
Two bacterial isolates, designated strains 5420S-26(T) and 5516S-1(T), were recovered from air samples collected in Suwon, Korea. Cells of both strains were aerobic, Gram-negative, motile rods. Phylogenetically, these strains were positioned within the radius of the genus Massilia. 16S rRNA gene sequence analysis showed that the strains shared 97.3 % sequence similarity and had sequence similarities of 94.9-98.1 % with respect to type strains of species belonging to the genus Massilia. In DNA-DNA hybridization tests, the two strains showed <39 % relatedness with respect to strains of closely related species of the genus Massilia and 27 % relatedness to each other. Both strains contained Q-8 as the predominant isoprenoid quinone and possessed summed feature 3 (comprising C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH) as the major fatty acid. Strain 5516S-1(T) was found to contain the fatty acid C(20 : 0) (in small amounts), a feature that served to distinguish it from both 5420S-26(T) and recognized members of the genus Massilia. The DNA G+C contents of 5420S-26(T) and 5516S-1(T) were 67.8 and 66.6 mol%, respectively. Phylogenetic, phenotypic and chemotaxonomic data accumulated in this study revealed that 5420S-26(T) and 5516S-1(T) represent novel species of the genus Massilia, for which the names Massilia niabensis sp. nov. (type strain 5420S-26(T) =KACC 12632(T) =DSM 21312(T)) and Massilia niastensis sp. nov. (type strain 5516S-1(T) =KACC 12599(T) =DSM 21313(T)) are proposed, respectively.
Many people spend considerable amount of time each day in equine stable environments either as employees in the care and training of horses or in leisure activity. However, there are few studies available on how the stable environment affects human airways. This study examined in one horse stable qualitative differences in indoor air during winter and late summer conditions and assessed whether air quality was associated with clinically detectable respiratory signs or alterations to selected biomarkers of inflammation and lung function in stable personnel.
The horse stable environment and stable-workers (n = 13) in one stable were investigated three times; first in the winter, second in the interjacent late summer and the third time in the following winter stabling period. The stable measurements included levels of ammonia, hydrogen sulphide, total and respirable dust, airborne horse allergen, microorganisms, endotoxin and glucan. The stable-workers completed a questionnaire on respiratory symptoms, underwent nasal lavage with subsequent analysis of inflammation markers, and performed repeated measurements of pulmonary function.
Measurements in the horse stable showed low organic dust levels and high horse allergen levels. Increased viable level of fungi in the air indicated a growing source in the stable. Air particle load as well as 1,3-beta-glucan was higher at the two winter time-points, whereas endotoxin levels were higher at the summer time-point. Two stable-workers showed signs of bronchial obstruction with increased PEF-variability, increased inflammation biomarkers relating to reported allergy, cold or smoking and reported partly work-related symptoms. Furthermore, two other stable-workers reported work-related airway symptoms, of which one had doctor's diagnosed asthma which was well treated.
Biomarkers involved in the development of airway diseases have been studied in relation to environmental exposure levels in equine stables. Respirable dust and 1,3-beta-glucan levels were increased at winter stabling conditions. Some employees (3/13) had signs of bronchial obstruction, which may be aggravated by working in the stable environment. This study contributes to the identification of suitable biomarkers to monitor the indoor horse stable environment and the personnel. An improved management of the stable climate will be beneficial for the health of both stable workers and horses.
People working in cattle, swine and poultry barns have a higher prevalence of respiratory symptoms and decreased lung function. There is scant evidence regarding the respiratory health of humans working in horse barns, although it is well documented that stabled horses have a high prevalence of airway disease.
To determine whether people spending time in horse barns have a higher prevalence of self-reported respiratory symptoms than non-exposed controls.
A cross-sectional questionnaire study was conducted from May 2005 to January 2006 to investigate the prevalence of self-reported respiratory symptoms in 82 barn-exposed subjects and 74 control subjects. Logistic regression and the chi-square test were used to analyse the data.
There was a significantly higher prevalence of self-reported respiratory symptoms in the barn-exposed group (50%) versus the control group (15%). Exposure to horse barns, smoking and family history of asthma or allergies was independent risk factors for respiratory symptoms. High exposure to the horse barn yielded a higher odds ratio for self-reported respiratory symptoms (8.9).
Exposure to the equine barn is a risk factor for respiratory symptoms. Investigation of organic dust exposures, lung function and horse dander allergies in the barn-exposed group will be necessary to determine how best to protect the health of this group.
Horses are used mainly for sports and leisure activities and are predominantly kept in closed individual straw-bedded stalls for a long time during the day, especially in cold weather. Horses are may therefore be exposed to high concentrations of particulate matter and microorganisms from the bedding and fodder material. The dangers posed by exposure the horses to high pollutant concentrations for a long period are respiratory diseases. Thus, the aim of the present research was to detect the potential PM and mold emitting sources in typical horse stables and to identify the concentrations of the particles in the stable air on the basis of quantitative and qualitative studies for the PM and mold concentrations. Long-term measurements of particles and molds were conducted in two horse stables located in Röttgen city, Germany. Collected data from two stables were checked for possible correlations between particulate matter and mold spores. Simulation experiments for the emitted particulates during feeding hay were conducted with a particulate chamber. High diurnal fluctuations in concentrations were observed due to the daily activities in the stables. Fine particles were dominant in the air, especially with a size 0.3–0.4 μm. Mold concentrations in the stables ranged from 3.9 to 5.9 × 10⁵ CFU/m³. The most common mold genera were Eurotium, Wallemia, and Cladosporium. The latter two were found in the straw and hay. A limited prognosis occurred of the mold fungus concentration in horse stables on the basis of airborne particle concentration.
Adverse respiratory health effects in the agricultural industry have been linked to particulate endotoxin exposure. However, whether the endotoxin concentration is significantly correlated to the size of the particle remains an open question. To date, limited research has been conducted to assess particulate endotoxin exposures in the agricultural industry in general or the equine industry in particular. A task-based exposure assessment was conducted to characterize the endotoxin levels of inhalable and respirable particles on four Kentucky farms during the summer season. We conducted personal sampling of respirable and inhalable particles (n = 75) across all four farms and particulate endotoxin (n = 58) on two of them. Simultaneously, we collected real-time area samples across all four farms by task – horse care, filing hooves, cleaning stalls, cleaning barns, cleaning dry lots, and cleaning trucks. The endotoxin concentration of inhalable particles (geometric mean: 50.2–1,024 EU/m³) was ~50 times higher than that of respirable particles (geometric mean: 1.72–19.0 EU/m³). Horse care generated the lowest endotoxin concentrations for both particle sizes, while cleaning tasks tended to produce higher concentrations. There was no significant correlation between the endotoxin and particle concentrations for each size fraction based on tasks by farm (R² = 0.069 for inhalable; 0.214 for respirable). The equine workers in this study were exposed to higher endotoxin concentrations than workers in other industries, such as the swine industry. Providing exposure control guidelines and recommendations to the equine industry is necessary to reduce long-term endotoxin exposure and to prevent adverse respiratory symptoms.
Microorganisms are ubiquitous in the atmosphere, where they can disperse for a long distance. However, it remains poorly understood how these airborne microorganisms vary and which factors influence the microbial distribution in different anthropogenic activity regions. To explore the regional differences of bacteria and fungi in airborne particles, PM 2.5 and PM 10 samples were collected in the urban and rural areas of Hangzhou. The bacterial and fungal communities in the urban atmosphere was more similar to each other than those in the rural atmosphere. Analyses conducted by the concentration weighted trajectory model demonstrated that the local environment contributed more to the similarity of airborne bacteria and fungi compared with the atmospheric transport. The concentrations of local air pollutants (PM 2.5 , PM 10 , NO 2 , SO 2 and CO) were positively correlated with the similarity of the bacterial and fungal communities. Additionally, the concentrations of these air pollutants in the urban site were about 1.5 times than those in the rural site. This implicated that anthropogenic activity, which is the essential cause of air pollutants, influenced the similarity of airborne bacteria and fungi in the urban area. This work ascertains the outdoor bacterial and fungal distribution in the urban and the rural atmosphere and provides a prospective model for studying the contributing factors of airborne bacteria and fungi. Exploring the distribution difference and influence factors of airborne bacteria and fungi in urban and rural areas shed light on the relationships between airborne microorganisms and air pollutants.
The genus Micrococcus consists of Gram-positive spheres occurring in tetrads and in irregular clusters that are usually nonmotile and nonsporeforming. They are catalase positive and usually aerobic with strictly respiratory metabolism. Most species produce carotenoid pigments. The GC content of the DNA ranges from 65 to 75 mol%. There are nine species recognized in the genus (see later, Table 2). The data on GC content of the DNA, chemical cell wall analysis, and a comparative analysis of 16S rRNA sequences indicate that the genus Micrococcus is more closely related to the genus Arthrobacter than it is to other coccoid genera such as Staphylococcus and Planococcus (Keddie, 1974; Kloos et al., 1974; Kocur et al., 1971; Stackebrandt and Woese, 1979). For these reasons it cannot be included with the genera Staphylococcus and Planococcus in the same family Micrococcaceae. Therefore, both the genus Micrococcus and the genus Arthrobacter should be regarded as closely related, but separate genera.
During a 2-year period from 1996 to 1997, a total of 1,089 staphylococci were isolated from the nares and skin of 99 healthy horses reared at 15 farms in the Hidaka District, Hokkaido, Japan. Identification of the 1,089 isolates resulted in the following species distribution: Staphylococcus xylosus, 883 isolates (81.1%); S. sciuri (subspecies not identified), 133 (12.2%); S. cohnii subsp. cohnii, 16; S. hominis (subspecies not identified), 11; S. haemolyticus, 10; S. gallinarum, 7; S. lentus, 7; S. simulans, 3; S. cohnii subsp. urealyticum, 2; S. epidermidis, I; S. intermedius, 1; S. saprophyticus (subspecies not identified), 1; S. lugdunensis, 1; S. schleiferi subsp. schleiferi, 1; S. capitis (subspecies not identified), 1; S. caprae, 1; unidentifiable, 10. No difference was found between the nares and the skin regarding staphylococcal species distribution. This suggests that for the most part S. xylosus and S. sciuri comprise the staphylococcal flora in horses. For identification, 16S-23S rDNA intergenic spacer PCR analysis was used as well as the Api Staph system. It was confirmed that this method is a useful tool for identification when there are many isolates to deal with. In this study, we designed two primer sets for PCR specific for 16S rDNA of S. sciuri or S. lentus in order to distinguish the 2 species, because it is difficult to identify them definitively in terms of phenotypic characteristics alone. These primer sets were useful in distinguishing these species.
A suspicion for fungal pneumonia must be established in the equine patient based on clinical signs, geographical location, and exclusion of more common pathogens. From there, a combination of diagnostic procedures must be used to achieve a definitive diagnosis of the exact fungal agent. As antifungal drugs become more affordable and effective in horses, successful treatment may be reported more frequently in cases that are diagnosed early. Although relatively uncommon, fungal pneumonia is an important class of respiratory tract infection that has a need for further research and treatment trials, as there is a unique group of horses that would benefit from appropriate and effective treatment.
Among athletic/sports animals, the horse has a unique ability to increase its oxygen uptake by a factor of 60 during heavy exercise. This is achieved by physiological adaptations of all the links in the oxygen chain. Ventilation is increased by a factor of 30. Since the horse is a compulsory nasal breather, this hyperpnea necessitates high transmural pressure changes, which may be responsible for the dynamic collapse of the airways. Blood flow is increased by a factor of 10. Since the left ventricle is not very compliant, this increase necessitates a high filling pressure in the pulmonary circulation, which may induce capillary stress failure and exercise-induced pulmonary haemorrhage. Lastly, oxygen transport is improved by splenic contraction which increases haemoglobinemia by 50%.Sports horses frequently suffer from several problems, which are related either to endogenous or exogenous stresses experienced during their career. These stresses, caused by the use of the horse as a competition animal, may lead to several medical problems.At a systemic level, endogenous stresses include hyperkaliemia, lactacidemia, and hyperthermia; oxidative stress may induce problems at a general, and/or a pulmonary level.External factors, e.g. poor quality of inspired air, transport, hot and humid ambient conditions, and microbiological agents, may also induce abnormal body attacks, and lead to health problems.
The relationship between the microbial world and asthma is not well understood. Although we know that the most potent triggers of wheezing attacks are viruses, we do not understand whether and how they contribute to disease onset and progression. Even less is known about the relationship between asthma and bacteria.
The clearest evidence stems from studying asthma exacerbations or wheezing episodes. In clinical studies viruses can be detected in up to 90% of such episodes 1, with rhinovirus being most commonly identified, followed by respiratory syncytial virus (RSV) in the first years of life. Other viruses such as parainfluenza, metapneumovirus, coronavirus, adenovirus, influenza and enteroviruses have also been implicated, mostly in older patients. In ∼10% of episodes multiple viruses were found 2. Most recently, the H1N1 virus has been reported to be more prevalent among asthmatics than other patients 3. In a recent high-risk birth cohort, children with wheezing illnesses triggered by rhinovirus infections early in life were at risk for the subsequent development of asthma up to 6 yrs of age 2.
However, it remains unclear whether viral infections are causal factors for the new onset of disease by impacting on the host's immune response or whether they merely unmask a host's underlying susceptibility to develop asthma by triggering exacerbations. It has been proposed that asthmatics may have subtle deficiencies in their immune response resulting in reduced antiviral activity and increased susceptibility for viral infections, especially of the lower respiratory tract. Corne et al. 4 recruited 76 cohabiting couples where only one partner had asthma and compared the frequency, severity and duration of rhinovirus infection between them. The authors found that asthmatics develop more severe and longer lasting respiratory symptoms following rhinovirus infections than their spouses 4. Message et al. 5 experimentally infected adult …
beta (1-->3)-Glucans are known for their potent ability to induce nonspecific inflammatory reactions and are believed to play a role in bioaerosol-induced respiratory symptoms. An inhibition enzyme immunoassay (EIA) was developed for the quantitation of beta (1-->3)-glucans in dust samples from occupational and residential environments. Immunospecific rabbit antibodies were produced by immunization with bovine serum albumin-conjugated laminarin [beta (1-->3)-glucan] and affinity chromatography on epoxy-Sepharose-coupled beta (1-->3)-glucans. The laminarin-based calibration curve in the inhibition EIA ranged from approximately 40 to 3,000 ng/ml (15 to 85% inhibition). Another beta (1-->3)-glucan (curdlan) showed a similar inhibition curve but was three to five times less reactive on a weight basis. Pustulan, presumed to be a beta (1-->6)-glucan, showed a parallel dose-response curve at concentrations 10 times higher than that of laminarin. Control experiments with NaIO4 and beta (1-->3)-glucanase treatment to destroy beta (1-->6)- and beta (1-->3)-glucan structures, respectively, indicate that the immunoreactivity of pustulan in the assay was due to beta (1-->3)-glucan and not to beta (1-->6)-glucan structures. Other polysaccharides, such as mannan and alpha (1-->6)-glucan, did not react in the inhibition EIA. Beta (1-->3)-Glucan extraction of dust samples in water (with mild detergent) was performed by heat treatment (120 degrees C) because aqueous extracts obtained at room temperature did not contain detectable beta (1-->3)-glucan levels. The assay was shown to detect heat-extractable beta (1-->3)-glucan in dust samples collected in a variety of occupational and environmental settings. On the basis of duplicate analyses of dust samples, a coefficient of variation of approximately 25% was calculated. It was concluded that the new inhibition EIA offers a useful method for indoor beta (1-->3)-glucan exposure assessment.
The genus Pseudomonas was described in 1894 and is one of the most diverse and ubiquitous bacterial genera whose species have been isolated worldwide in all kinds of environments, from the Antarctica to the Tropics, present in sediments, clinical samples, plant, fungi and diseased animal specimens, water, soil, plant rhizosphere, sea, deserts, etc. The taxonomy of the genus has been controversial for years since a lot of bacterial taxa initially included in genus Pseudomonas have been reclassified in other genera or species from a different class of Proteobacteria over the years, as techniques for characterization and classification of microorganisms improved, aiming to set a phylogenetic classification of the species. In this review, the historical evolution of the taxonomy of Pseudomonas is described, and the currently valid criteria and future challenges for taxonomy of the genus and techniques used to achieve the necessary characterization for classifying the species are discussed. Finally, all the validly published Pseudomonas species at present are listed with an overview of their diversity and ecology.