Sabela Balboa

University of Santiago de Compostela | USC · Department of Microbiology and Parasitology

The growing concern about antibiotic-resistant microorganisms has focused on the sludge from wastewater treatment plants (WWTPs) as a potential hotspot for their development and spread. To this end, it seems relevant to analyze the changes on the microbiota as a consequence of the antibiotics that wastewater may contain. This study aims at determin...

There is scarce information about the biotransformation of organic micropollutants (OMPs) under anoxic conditions. In this study, a heterotrophic denitrifying bioreactor was set up to study the fate of several OMPs from metabolic and microbiological points of view. Primary metabolic activity was increased by adding progressively higher nitrogen loa...

The members of genus Vibrio have acquired a great importance because several are associated with human disease. These members are autochthonous to aquatic environments mcludimg estuarine, coastal waters and sediments worldwide, and some species are well-known pathogens of marine organisms including fish, crustaceans, corals and mollusks. The aim of...

The study of the microbiota associated to clams is important not only to know their sanitary status but also to prevent pathobiology events. The use of different microbiological techniques can help to obtain a better picture of the bacterial diversity of clams as well as to isolate new bacterial taxa. In this study, two clam species, Ruditapes decu...

This work investigates the impact of the sugar-to-protein (STP) ratio on the outcome of their anaerobic cofermentation in terms of substrate conversion and product selectivity. For this purpose, a continuous...

Background A One Health approach requires integrative research to elucidate antimicrobial resistance (AMR) in the environment and the risks it poses to human health. Research on this topic involves experts from diverse backgrounds and professions. Shortcomings exist in terms of consistent, complete, and transparent reporting in many environmental s...

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is shed in the feces of infected people. As a consequence, genomic RNA of the virus can be detected in wastewater. Although the presence of viral RNA does not inform on the infectivity of the virus, this presence of genetic material raised the question of the effectiveness of treatmen...

Urban wastewater systems (UWSs) are a main receptacle of excreted antibiotic resistance genes (ARGs) and their host microorganisms. However, we lack integrated and quantitative observations of the occurrence of ARGs in the UWS to characterize the sources and identify processes that contribute to their fate. We sampled the UWSs from three medium-siz...

SARS-CoV-2 genetic material is detectable in the faeces of a considerable part of COVID-19 cases and hence, in municipal wastewater. This fact was confirmed early during the spread of the COVID-19 pandemic and prompted several studies that proposed monitoring its incidence by wastewater. This paper studies the fate of SARS-CoV-2 genetic material in...

Integrated and quantitative observations of antibiotic resistance genes (ARGs) in urban water systems (UWSs) are lacking. We sampled three UWSs for clinically important extended spectrum β-lactamase (ESBL) and carbapenemase (CP) genes, mobile genetic elements and microbial communities. Sewage – especially from hospitals – carried substantial loads...

A bstract SARS-CoV-2 genetic material is detectable in the faeces of a considerable part of COVID-19 cases and hence, in the urban wastewater. This fact was confirmed early during the spread of the COVID-19 pandemic and prompted several studies that proposed monitoring its incidence by wastewater. This paper studies the fate of SARS-CoV-2 genetic m...

The upper zone of the background walls of the processional cloister of the Monastery of San Martiño Pinario (Santiago de Compostela, Galicia, Spain) is affected by a deep green, highly hydrophobic subaerial biofilm. The pattern that the biofilm follows the walls suggests that particular microclimatic conditions induce changes in the biofilm propert...

A comparison of the culturable microbiota present in the different compartments of a great scallop (Pecten maximus) hatchery with two experimental production systems, FTS and RAS, throughout a cycle of larval rearing was carried out. All isolates obtained from broodstock gonads, larvae, tank water, biofilm, microalgae, UV‐treated water and biofilte...

Two Gram-negative strains obtained from tank water in a scallop hatchery in Norway, were phenotypically and genotypically characterized in order to clarify their taxonomic position. On the basis of 16S rRNA gene sequence analysis, these isolates, ATF 5.2T and ATF 5.4T, were included in the genus Halomonas, being their closest relatives H. smyrnensi...

[This corrects the article DOI: 10.3389/fmicb.2018.02077.].

[This corrects the article DOI: 10.3389/fmicb.2018.02077.].

Since the description of the genus Arcobacter in 1991, a total of 27 species have been described, although some species have shown 16S rRNA similarities below 95%, which is the cut-off that usually separates species that belong to different genera. The objective of the present study was to reassess the taxonomy of the genus Arcobacter using informa...

At present, the genus Edwardsiella compiles five species: E. tarda, E. hoshinae, E. ictaluri, E. piscicida and E. anguillarum. Some species of this genus such us E. ictaluri and E. piscicida are important pathogens of numerous fish species. With the description of the two latter species, the phylogeny of Edwardsiella became more complicated. With t...

Skin ulcerations rank amongst the most prevalent lesions affecting wild common dab (Limanda limanda) with an increase in prevalence of up to 3.5% in the Belgian part of the North Sea. A complex aetiology of these ulcerations is suspected, and many questions remain on the exact factors contributing to these lesions. To construct the aetiological spe...

Until 2012, the genus Edwardsiella was composed by three species Edwardsiella tarda, Edwardsiella hoshinae and Edwardsiella ictaluri. In 2013, Edwardsiella piscicida, compiling fish pathogenic strains previously identified as E. tarda was described, and more recently a new species isolated from diseased eel was reported, namely Edwardsiella anguill...

Five strains were isolated from gonad of Great scallop (Pecten maximus) broodstock in a Norwegian hatchery. The study of 16S rRNA gene sequences showed that these isolates belong to Neptunomonas phycophila, a bacterium originally isolated from a symbiont of the anemone Aiptasia tagetes from Puerto Rico. The gyrB and rpoB genes sequences confirmed t...

So-called ‘cleaner fish’, including various wrasse (Labridae) species, have become increasingly popular in Norwegian salmon farming in recent years for biocontrol of the salmon louse, Lepeophtheirus salmonis. Cleaner fish mortalities in salmon farms are, however, often high. Various bacterial agents are frequently associated with episodes of increa...

Multilocus sequence analysis (MLSA) and multilocus sequence typing (MLST) are nowadays considered as gold standards in the study of microbial systematic, being both techniques based on the interpretation of the sequences of several housekeeping genes. In this context, the sequences can be analyzed from different points of view. On the one hand, the...

Four bacterial strains, LFT 1.7T, LT2C 2.5, LT4C 2.8 and TM 4.6, were isolated from Great scallop (Pecten maximus) larvae and tank seawater in a Norwegian hatchery and characterized by a polyphasic approach including phenotypic, chemotaxonomic and genomic traits. All of them were Gram-negative and motile rods, oxidase and catalase positive and requ...

Nine isolates obtained from a great scallop hatchery in Norway were characterized using a polyphasic approach. Strains were Gram-negative, aerobic and motile rods with oxidative metabolism. Phylogenetic analysis based on the sequences of 16S rRNA and rpoB genes showed that these strains formed two different groups associated with members of the gen...

Appendix 1: Table 1. Twitter course syllabus Appendix 2: Figure 3. Image captures of representative tweets posted during #microMOOCSEM course Appendix 3: Table 2. Structure of #microMOOCSEM lessons Appendix 4: Table 3. Activity of the Twitter account @SEMicrobiologia before and after the course Appendix 5: Figure 4. Evolution of the number of follo...

Online social networks are increasingly used by the population on a daily basis. They are considered a powerful tool for science communication and their potential as educational tools is emerging. However, their usefulness in academic practice is still a matter of debate. Here, we present the results of our pioneering experience teaching a full Bas...

Seven isolates were obtained from different culture stages of carpet shell clam (Ruditapes decussatus) reared in a bivalve hatchery (Galicia, NW Spain). Three groups were differentiated by genotyping techniques and phenotypic profiles and representative trains were selected to further taxonomic studies. These strains were studied by a polyphasic ap...

One bacterial strain was taxonomically characterized by means of a genomic approach comprising 16S rRNA gene sequence analysis, multilocus sequence analysis (MLSA), the DNA G+C content, whole genome analyses (ANI and GGDC), and phenotypic characterization. The strain CAIM 1540T was isolated from a cultured oyster Crassostrea corteziensis in La Cruz...

Aeromonas species are inhabitants of aquatic environments and are able to cause disease in humans and fish among other animals. In aquaculture, they are responsible for the economically important diseases of furunculosis and motile Aeromonas septicaemia (MAS). Whereas gastroenteritis and wound infections are the major human diseases associated with...

A motile, facultative anaerobic, marine bacterial isolate (CAIM 1437T) was obtained from a cultured oyster (Crassostrea gigas) in Sonora, México. The strain was studied by a phylogenetic analysis based on sequences of the 16S rRNA and five housekeeping genes i.e. ftsZ, gapA, pyrH, recA, and topA. Comparison of the almost-complete 16S rRNA gene sequ...

Tenacibaculum soleae is a recently described pathogen that has been reported as the causative agent of considerable losses in sole cultures in Spain. This report documents the first case of T. soleae as an etiological agent of tenacibaculosis in farmed sea bass Dicentrarchus labrax. Its identification was performed employing phenotypical, serologic...

A polyphasic study was undertaken to clarify the taxonomic position of Streptococcus phocae strains isolated from Atlantic salmon (Salmo salar) cage-farmed in Chile. Four salmon and three seal isolates showed minor differences in the SDS-PAGE protein analysis. Thus, a major protein band present in the salmon isolates, of approximately 22.4 kDa, was...

The genus Vibrio consists of more than 100 species grouped in 14 clades that are widely distributed in aquatic environments such as estuarine, coastal waters, and sediments. A large number of species of this genus are associated with marine organisms like fish, molluscs and crustaceans, in commensal or pathogenic relations. In the last decade, more...

Vibrio tapetis is a fastidious slow-growing microorganism that causes the Brown Ring Disease in clams. Recently, two subspecies for this bacterial pathogen have been proposed. We have developed a multilocus sequence typing scheme and performed evolutionary studies of V. tapetis population using the great majority of isolates of V. tapetis obtained...

The culture of clams represents an important marine resource and is of great economic importance for many coastal areas worldwide, including the coast of Galicia (NW Spain). In some of these areas, natural beds of authoctonous clams have been harvested beyond their maximum sustainable yield, which has led to the introduction of the foreing species...

Thirteen culture media were evaluated at two temperatures for the growth and isolation of Vibrio tapetis. The bacterium showed similar growth dynamics at 15 °C or 25 °C, being faster at 15 °C regardless the general media employed. Best growth of V. tapetis was obtained on Agar Seawater (ASWT) (1.7 × 10(6)cfu/ml), Mannitol Marine Agar (MMA) (2.6 × 1...

The aim of the present study was to analyze the intraspecific genetic variability within Vibrio alginolyticus isolated strains from different Tunisian aquatic biotopes by using two PCR–based techniques. Seventy eight strains including nine Vibrio reference strains and sixty nine V. alginolyticus isolated strains from seawater, sediment, fish (disea...

Vibrio tapetis is the etiological agent of brown ring disease (BRD) in clams, one of the most threatening diseases affecting this commercially important bivalve. In this study we have constructed a proteome reference map of the V. tapetis type strain CECT 4600(T). Eighty-two proteins, consistently present in all 2D-gels, were identified by mass spe...

Vibrio tapetis is the etiological agent of brown ring disease (BRD) in clams. Phenotypic, antigenic and genetic variability have been demonstrated, with three groups being established associated with host origin. In this work we analyze the variability of representative strains of these three groups, CECT 4600(T) and GR0202RD, isolated from Manila...

In this study the specificity and sensitivity of three primer pairs, Jvt1-Jvt2, VtF-VtR and VtKF-VtKR, for the detection of Vibrio tapetis were evaluated in parallel using 23 V. tapetis strains isolated from different mollusc and fish species and with different geographical origin, as well as 29 representatives of related Vibrio species. The three...

Vibrio parahaemolyticus is a natural inhabitant of marine environments and constitutes part of the autochthonous microbial communities, but is also associated with human gastroenteritis, wound infections and septicemia. Recently, a number of clinical cases of infection due to ingestion of seafood contaminated with V. parahaemolyticus and potentiall...

The first isolation of Vibrio tapetis from Wedge sole (Dicologoglossa cuneata) is reported. The bacterium was recovered from ulcers of ailing cultured fish, from two different outbreaks occurred in spring 2005. The four isolates found (a200, a201, a204 and a255) were biochemically, genetically and serologically characterized and diagnosis was confi...

This paper describes a pathological condition in intensive reared Atlantic salmon (Salmo salar), restricted to the appearance of pseudo-membranes covering internal organs (i.e. spleen, liver, heart and others) associated with the presence of large numbers of a Gram-positive bacteria. Isolate 79043-3, obtained as pure culture from affected fish, was...

Facultatively anaerobic marine bacteria isolated from cultured clams, Ruditapes decussatus and Ruditapes philippinarum, were previously investigated using amplified fragment length polymorphism (AFLP) and 16S rRNA gene sequence analyses. The isolates formed two AFLP clusters and belonged to the genus Vibrio, more precisely to the Splendidus clade....

A group of four motile facultative anaerobic marine isolates (Rd 8.15(T) [=CECT 7224(T), =LMG 23850(T)], Rd 16.13, Rd 6.8 [=LMG 25696] and Rd2L5) were obtained from cultured clams (Ruditapes philippinarum and Venerupis pullastra) in Galicia, north-western Spain. They formed a tight phylogenetic group based on sequences of the 16S rRNA gene and the...

Shellfish production is seriously affected by bacterial pathogens that cause high losses in hatcheries and in the aquaculture sector. A number of Vibrio species are considered important pathogens and have provoked severe mortality outbreaks. The pathologies caused by vibrios in bivalves have been described since the 1960s; however, over recent year...

Four strains isolated from cultured Manila clam, Ruditapes philippinarum, in the north-western coast of Spain were characterized phenotypically and genotypically. Phylogenetic analyses based on the 16S rRNA gene sequences indicated that these bacteria were closely related to Aliivibrio wodanis, Aliivibrio salmonicida, Aliivibrio fischeri and Aliivi...

Seven non-motile, facultatively anaerobic, alginolytic marine bacteria were isolated from the cultured clams Ruditapes philippinarum and Ruditapes decussatus. Phylogenetic analysis based on 16S rRNA gene sequences showed that these marine bacteria were closely related to the recently described species Vibrio comitans, Vibrio rarus and Vibrio inusit...

The aim of the present study was to characterize and identify vibrios isolated from cultured clams in Galicia (NW Spain). A total of 759 isolates were obtained, phenotypically characterized, grouped and assigned to the genus Vibrio. Subsequently, the genomic diversity of 145 representative strains was analyzed by means of amplified fragment length...

The aims of the study were to evaluate a new PCR protocol designed to detect Aeromonas salmonicida in fish tissues and to develop a non-destructive method for the diagnosis of furunculosis. A set of primers (Fer3, Fer4), flanking a fragment of the fstA gene (coding for the ferric-siderophore receptor) was designed, showing to be sensitive and speci...

The biochemical, serological and genetic characteristics of six strains of Pseudomonas anguilliseptica isolated from cod, Gadus morhua, in Scotland were compared to well characterized isolates of this same bacterial species but of different origin. Biochemical and physiological analyses showed that this group of isolates was highly homogeneous, the...

Brown Ring Disease (BRD), which affects the Manila clam in Europe, is caused by the bacterium, Vibrio tapetis. BRD has been diagnosed in Ireland on only one occasion (1997) although the aetiological agent has recently been detected in apparently healthy Manila clams from a number of sites around the Irish coast. The present work investigated the su...