[Show abstract][Hide abstract] ABSTRACT: Trichinella spp. are zoonotic parasites transmitted to humans by the consumption of raw or insufficiently cooked meat of different animal species. The most common source of infection for humans is meat from pigs and wild boar (Sus scrofa). The aim of the present work was to evaluate the incidence of Trichinella spp. infections in wild boar hunted in Latvia over a 38 year interval (1976 to 2013).
A total 120,609 wild boars were individually tested for Trichinella spp. by trichinoscopy and, in case of negativity, by artificial digestion of 25 g muscles, in the 1976-2005 period, and by artificial digestion of 25-50 g muscles in the 2006-2013 period. Trichinella spp. larvae were identified at the species level by multiplex PCR.
In the study period, the overall prevalence of infected wild boar was 2.5%. Trichinella britovi was the predominant (90%) species. The incidence of Trichinella spp. infection in wild boar exhibited two different trends. From 1976 to 1987, the incidence of infected/hunted wild boar increased from 0.23% to 2.56%, then it decreased to 0.19 in 1994. Thereafter, the incidence fluctuated between 0.05% and 0.37%. A statistically significant (P < 0.05) correlation (r = 0.54; p = 0.0199) was found between the trend of Trichinella spp. incidence in hunted wild boar and the number of snow cover days from 1976 to 1993. From 1997 to 2013, the estimated wild boar population of Latvia increased by 4.9 times and the hunting bag by 9.7 times, with a stable incidence of Trichinella spp. in the population. It follows that the biomass of Trichinella spp. larvae and of T. britovi, in particular, increased.
The incidence trends of Trichinella spp. in wild boar could be related to the role played by the snow in reducing the thermal shock and muscle putrefaction which increases the survival of the larvae in muscle tissues of carrion in the 1976-1993 period; and, in the 1997-2013 period, to the increased biomass of Trichinella spp. due to the increased carnivore populations, which are the main reservoirs of these parasites.
[Show abstract][Hide abstract] ABSTRACT: Several species of protozoa cause acute or chronic gastroenteritis in humans, worldwide. The burden of disease is particularly high among children living in developing areas of the world, where transmission is favored by lower hygienic standards and scarce availability of safe water. However, asymptomatic infection and polyparasitism are also commonly observed in poor settings. Here, we investigated the prevalence of intestinal protozoa in two small fishing villages, Porto Said (PS) and Santa Maria da Serra (SM), situated along the river Tietê in the State of São Paolo, Brazil. The villages lack basic public infrastructure and services, such as roads, public water supply, electricity and public health services.
Multiple fecal samples were collected from 88 individuals in PS and from 38 individuals in SM, who were asymptomatic at the time of sampling and had no recent history of diarrheal disease. To gain insights into potential transmission routes, 49 dog fecal samples (38 from PS and 11 from SM) and 28 river water samples were also collected. All samples were tested by microscopy and PCR was used to genotype Giardia duodenalis, Blastocystis sp., Dientamoeba fragilis and Cryptosporidium spp.
By molecular methods, the most common human parasite was Blastocystis sp. (prevalence, 45% in PS and 71% in SM), followed by D. fragilis (13.6% in PS, and 18.4% in SM) and G. duodenalis (18.2% in PS and 7.9% in SM); Cryptosporidium spp. were not detected. Sequence analysis revealed large genetic variation among Blastocystis samples, with subtypes (STs) 1 and 3 being predominant, and with the notable absence of ST4. Among G. duodenalis samples, assemblages A and B were detected in humans, whereas assemblages A, C and D were found in dogs. Finally, all D. fragilis samples from humans were genotype 1. A single dog was found infected with Cryptosporidium canis. River water samples were negative for the investigated parasites.
This study showed a high carriage of intestinal parasites in asymptomatic individuals from two poor Brazilian villages, and highlighted a large genetic variability of Blastocystis spp. and G. duodenalis.
[Show abstract][Hide abstract] ABSTRACT: Trichinellosis is a zoonotic disease caused by Trichinella muscle larvae (ML) through ingestion of raw or undercooked meat. To date, 12 taxa are recognized in this genus, of which four are circulating in Europe (Trichinella spiralis, Trichinella nativa, Trichinella britovi and Trichinella pseudospiralis). T. spiralis and T. britovi circulate in European wildlife and occur simultaneously in the same host species. The possibility of hybrid formation between T. britovi and T. spiralis has hardly been addressed and so far, results of experimental hybridisation attempts between T. britovi and T. spiralis are inconclusive. The aim of the present study was to analyse molecular polymorphisms of single T. spiralis and T. britovi (ML) from natural infections based on nuclear 5S rDNA intergenic spacer region (5S rDNA-ISR) and mitochondrial cytochrome c oxidase 1 (CO1) gene sequences. Six haplotypes of the 5S rDNA intergenic spacer region (5S rDNA-ISR) and 14 of the cytochrome c oxidase 1 (CO1) gene were demonstrated in 89 individual T. britovi ML from Latvia and Poland. In contrast, only two haplotypes were observed at both 5S rDNA-ISR and CO1 of 57 individual T. spiralis ML from Polish wild boar and red foxes. Moreover, this study demonstrates hybridisation in eight individual ML between T. britovi and T. spiralis under natural conditions in four Polish wild boar and two red foxes, revealed by combining 5S rDNA-ISR and CO1 sequence information of individual Trichinella ML. To our knowledge, this is the first report of interspecies hybridisation between T. spiralis and T. britovi under field conditions.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 10/2015; 36. DOI:10.1016/j.meegid.2015.10.005 · 3.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate the spatial distribution of the Trichinella spp. and the factors influencing their circulation in Hungary, 4086 red foxes (Vulpes vulpes) and 0.32 million wild boars (Sus scrofa) were tested for Trichinella spp. infection in Hungary from 2006 to 2014. Trichinella spp. larvae from 86 (2.1%) foxes and 58 (0.02%) wild boars were identified by multiplex PCR as Trichinella britovi, Trichinella spiralis or Trichinella pseudospiralis. T. britovi was the dominant species in both foxes and wild boars (87.5% and 67.3%) followed by T. spiralis (11.2% and 31.0%) and T. pseudospiralis (1.3% and 1.7%). There was no correlation between environmental parameters in the home range of foxes and wild boars and the T. spiralis larval counts, but there was a positive correlation between the boundary zone of Hungary and T. spiralis infection. These results indicate that the distribution of T. spiralis in the Hungarian wildlife is determined by the transborder transmission of the parasite from the surrounding endemic countries. Based on the statistical analysis, non-agricultural areas and the mean annual temperature were the major determinants of the spatial distribution of T. britovi in Hungary. The positive relationship with non-agricultural areas can be explained by the generalist feeding behaviour including scavenging of foxes in these areas. The negative relationship with the mean annual temperature can be attributed to the slower decomposition of wildlife carcasses favouring a longer survival of T. britovi larvae in the host carrion and to the increase of scavenging of foxes.
Magyar Allatorvosok Lapja 08/2015; 137(8):495-506. · 0.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The flagellated protozoan Giardia duodenalis is a worldwide parasite causing giardiasis, an acute and chronic diarrheal disease. Metabolism in G. duodenalis has a limited complexity thus making metabolic enzymes ideal targets for drug development. However, only few metabolic pathways (i.e, carbohydrates) have been described so far. Recently, the parasite homolog of the mitochondrial-like glycerol-3-phosphate dehydrogenase (gG3PD) has been identified among the interactors of the g14-3-3 protein. G3PD is involved in glycolysis, electron transport, glycerophospholipids metabolism and hyperosmotic stress response, and is emerging as promising target in tumor treatment. In this work, we demonstrate that gG3PD is a functional flavoenzyme able to convert glycerol-3-phosphate into dihydroxyacetone phosphate and that its activity and the intracellular glycerol level increase during encystation. Taking advantage of co-immunoprecipitation assays and deletion mutants, we provide evidence that gG3PD and g14-3-3 interact at the trophozoite stage, the intracellular localization of gG3PD is stage dependent and it partially co-localizes with mitosomes during cyst development. Finally, we demonstrate that the gG3PD activity is affected by the antitumoral compound 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX), that results more effective in vitro at killing G. duodenalis trophozoites than the reference drug metronidazole. Overall, our results highlight the involvement of gG3PD in processes crucial for the parasite survival thus proposing this enzyme as target for novel anti-giardial interventions.
Frontiers in Microbiology 06/2015; 06. DOI:10.3389/fmicb.2015.00544 · 3.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Parasites of the genus Trichinella are zoonotic nematodes common in carnivores throughout the world. We determined the prevalence and species of Trichinella infections in Florida panthers (Puma concolor coryi).Methods
Tongues from Florida panthers were collected at necropsy and examined by pepsin-HCl artificial digestion for infection with Trichinella spp. DNA was extracted from larvae and multiplex PCR using Trichinella species-specific primers was used to genotype the worms.Results Trichinella spp. larvae were detected in 24 of 112 (21.4%; 14.6%¿30.3%) panthers. Sixteen of the panthers (14.3%) were infected with T. pseudospiralis, 1 (0.9%) was infected with T. spiralis, and 2 (1.8%) had mixed infections of T. pseudospiralis and T. spiralis. Trichinella spp. larvae from 5 panthers were not identified at the species level due to degraded DNA.Conclusions
This is the highest prevalence of T. pseudospiralis detected in North America up to now and suggests the Florida panther is a key mammalian reservoir of this parasite in southern Florida. Trichinella pseudospiralis can infect both mammals and birds indicting the source of infection for Florida panthers could be broader than believed; however, birds represent a small percentage (0.01%) of the cat¿s diet. Since wild pigs (Sus scrofa) can be parasitized by both T. pseudospiralis and T. spiralis and that these swine can comprise a large portion (~40%) of a panther¿s diet in Florida, we believe that Florida panthers acquired these zoonotic parasites from feeding on wild pigs.
[Show abstract][Hide abstract] ABSTRACT: Serology to monitor Trichinella spp. infection in pigs reared in controlled system has been claimed as a possible diagnostic tool. However, no international biological standards or reference materials exist to validate in house tests or commercial kits, and to improve the inter-laboratory comparability for the serological detection of anti-Trichinella IgG in pigs. In this work, potential reference sera have been prepared from four experimentally infected pigs. Sera were tested, aliquot, lyophilized, and maintained at +4 °C. Since one of the prerequisites for the development of any reference material is to plan and execute stability studies, isochronous studies for short and long term stability testing were carried out to evaluate the possible degradation effects of transportation and storage. The stability of the lyophilized serum samples at +4 °C, was arbitrarily assumed. For the short term stability study, two units were stored at -20 °C, +4 °C, +20 °C, and +50 °C for 0, 1, 2 and 4 weeks, and then tested in duplicate. For the long term stability study, the same number of units and replicates per unit were stored at -80 °C, -20 °C, and +4 °C, for 0, 6, 12, 18 and 24 months. In both studies, unit samples were selected randomly and tested on the same day under repeatability conditions. The linear regression versus time for each serum at each studied temperature was analyzed and then slopes were tested for significance. Further, uncertainty of the short and long term stability was calculated for a shelf life period of one week and three years, respectively. For all sera but one, and for all the studied temperatures but +50 °C, the data from the short term stability study indicate the absence of a significant trend that would hint at degradation. The slopes of the regression lines did not significantly vary from zero. Even if the uncertainty of the short term stability was variable among serum samples, the rate of degradation was considered acceptable. For the long term stability, slopes of the regression lines of two serum samples significantly varied from zero, indicating a trend of possible degradation during storage. The percentage of degradation deducted from the uncertainty of the long term study varied; however, two serum samples showed the lower rate of degradation at all the assayed temperatures. The most suitable temperatures for dispatching serum samples are -20 °C, +4 °C and +20 °C; whereas, -20 °C and -80 °C are suitable temperatures for serum storage.