Reservoir For Human Infection Research Articles

Zoonotic and genetically diverse subtypes of Blastocystis in US pre-weaned dairy heifer calves.

Blastocystis is an emerging zoonotic pathogen with global distribution. However, limited data exist on the prevalence and genetic diversity of Blastocystis in the USA and in food animals. We conducted the first large-scale molecular investigation of Blastocystis in the USA by testing 2539 fecal samples from dairy heifer calves from 13 states. Blastocystis was detected in 73 (2.9%) fecal samples and in 10 of the 13 tested states. Molecular characterization showed a wide diversity of subtypes. Eleven subtypes were identified, seven previously reported (ST-3, ST-4, ST-5, ST-10, ST-14, ST-17, and ST-21) and four potentially novel subtypes (named ST-23 to ST-26). Zoonotic subtypes 3, 4, and 5 were found in 67% (49) of the positive specimens in this population. Our results suggest that cattle could serve as reservoirs of infection for humans and other domestic animals highlighting the potential risk of zoonotic transmission for Blastocystis.

Seroprevalence and current infections of canine vector-borne diseases in Nicaragua

BackgroundVector-borne diseases constitute a major problem for veterinary and public health, especially in tropical regions like Central America. Domestic dogs may be infected with several vector-borne pathogens of zoonotic relevance, which may also severely compromise canine health.MethodsTo assess the prevalence of canine vector-borne diseases in Nicaragua, 329 dogs from seven cities, which were presented to the veterinarian for various reasons, were included in this study. Dogs were examined clinically and diagnostic blood samples were taken for analysis of packed cell volume (PCV) and presence of microfilariae as well as antigen of Dirofilaria immitis and antibodies to Ehrlichia spp., Anaplasma spp. and Borrelia burgdorferi (sensu lato) by use of a commercially available rapid ELISA. To detect current infections, specific PCRs for the detection of E. canis, A. platys and A. phagocytophilum were carried out on blood samples of the respective seropositive dogs. Microfilaremic blood samples, as well as D. immitis antigen positive samples were further subjected to PCR and subsequent sequencing for filarial species identification.ResultsAntibodies against Ehrlichia spp. were present in 62.9% of dogs, while Anaplasma spp. seroprevalence was 28.6%. Antibodies against species of both genera were detected in 24.9% of dogs. Borrelia burgdorferi (s.l.) antibodies were not detected. Dirofilaria immitis antigen was present in six animals (1.8%), two of which also showed D. immitis microfilariae in buffy coat. In addition to D. immitis, Acanthocheilonema reconditum was identified by PCR and sequencing in two of four additional microfilaremic blood samples, which were tested negative for D. immitis antigen. Current E. canis infections as defined by DNA detection were present in 58.5% of Ehrlichia-seropositive dogs, while 5.3% of Anaplasma-seropositive dogs were PCR-positive for A. platys, 2.2% for A. phagocytophilum and 16.0% for both Anaplasma species. Current E. canis infection had a statistically significant negative impact on PCV, whereas no relationship between infection status and clinical signs of disease could be observed.ConclusionsThese results indicate that canine vector-borne diseases are widespread in Nicaragua and that dogs may constitute a reservoir for human infection with E. canis, A. phagocytophilum and D. immitis. Thus, the use of repellents or acaricides to protect dogs from vector-borne diseases is strongly recommended.

Occurrence and subtype distribution of Blastocystis sp. in humans, dogs and cats sharing household in northern Spain and assessment of zoonotic transmission risk

Blastocystis sp. is probably the most common enteric parasite in humans globally. Although the role of Blastocystis in human disease is still controversial, epidemiological and experimental evidence suggests that pathogenicity may be associated with certain subtypes of the protist. Since the life cycle of Blastocystis is maintained through still elusive pathways, companion animals have attracted the attention of researchers as potential reservoirs of human infections. In order to evaluate the risk of zoonotic transmission of Blastocystis, we investigated the occurrence and molecular diversity of this microorganism in human, canine and feline populations sharing temporal and spatial settings in the province of Álava, northern Spain. A total of 268 (including 179 human, 55 canine and 34 feline) faecal specimens were obtained from 63 family households during February-December 2014. Detection of Blastocystis was achieved by PCR amplification and sequencing of small subunit rRNA genes. Blastocystis was found in 35.2% (95% CI: 0.29%-0.42%) of the human stool samples analysed, but not in any of the canine or feline faecal specimens investigated. Out of the 63 PCR-positive human samples, 84.1% (53/63) were successfully subtyped, allowing the identification of the subtypes ST2 (62.3%), ST3 (17.0%), ST1 (13.2%) and ST4 (7.5%). No mixed subtype infections were identified. Blastocystis carriage was independent of the gender and region of origin of the affected individuals, but children in the age groups of >5-10years and >10-15years were significantly more affected by the protist. None of the risk factors considered (water-use practices, contact with livestock, contact with individual undergoing diarrhoeal episodes) were associated with increased prevalence of Blastocystis. Our data demonstrate that pet dogs and cats play a negligible role as natural reservoirs of human Blastocystis infection in this geographic region, although the applicability of these results should be corroborated in future molecular epidemiological studies.

Enterocytozoon bieneusi genotypes in people with gastrointestinal disorders in Queensland and Western Australia

Enterocytozoon bieneusi is the commonest pathogenic microsporidian found in humans and animals in many countries, but there is scant information on this pathogen in Australia. Here, we conducted the first molecular epidemiological investigation of E. bieneusi in humans with gastrointestinal disorders in Queensland and Western Australia. Genomic DNAs derived from 605 individual faecal samples from children (n = 279) and adults (n = 326) were extracted, and then subjected to nested PCR-based sequencing of the internal transcribed spacer (ITS) of nuclear ribosomal DNA to detect and characterise E. bieneusi. Enterocytozoon bieneusi was detected in eight of 605 human faecal samples (1.3%), including five children (≤3 years of age) and one adult (58 years) in Queensland, and two children (≤3 years) in Western Australia. Analysis of ITS sequence data revealed two known zoonotic (ALP1 and Ind4) and three novel (Hum_q1–3) genotypes of E. bieneusi. Genotype ALP1 identified here in humans has been found previously in farmed alpacas in Australia. Phylogenetic analysis showed that genotypes ALP1, Hum_q1–2 and Ind4 belonged to E. bieneusi Group 1 (with zoonotic potential), whereas genotype Hum_q3 clustered within E. bieneusi Group 10, suggesting that some genotypes within Group 10 might have zoonotic potential. Further investigations of humans, alpacas, marsupials and other animals in Australia will be significant to understand the epidemiology of E. bieneusi in Australia, to identify possible reservoirs of human infection, and to assist in the prevention and control of human microsporidiosis.

First survey on zoonotic helminthosis in urban brown rats (Rattus norvegicus) in Spain and associated public health considerations

The brown rat, Rattus norvegicus, with a worldwide distribution, is the most commensal species among synanthropic rodents, since its main habitat, in urban as well as in rural areas, is always linked to humans. Therefore, people living in close proximity to rodent populations can be exposed to infection. Whereas bacteria and viruses are the best known rat-associated zoonoses in urban environments, the role of brown rats as reservoirs for helminth parasites and the associated risk for humans are less well known. Specifically, this role has not been analyzed in Spain to date. A total of 100 R. norvegicus trapped in the sewage system (n = 85), and parks (n = 15) of Barcelona was examined. The overall prevalence of helminth infection was 85%. The helminths found were Hymenolepis nana (17%), H. diminuta (33%) (Cestoda), Calodium hepaticum (17%), Eucoleus gastricus (28%), Aonchotheca annulosa (12%), Trichosomoides crassicauda (7%), Nippostrongylus brasiliensis (46%), Heterakis spumosa (62%), Gongylonema neoplasticum (20%) (Nematoda) and Moniliformis moniliformis (6%) (Acanthocephala). Five of the ten helminth species are considered zoonotic parasites, with rats acting as reservoirs for human infection, i.e. H. nana, H. diminuta, C. hepaticum, G. neoplasticum and M. moniliformis. G. neoplasticum and M. moniliformis are reported for the first time in urban rats in Europe. H. nana, H. diminuta and C. hepaticum are the most widespread species in European cities. For H. nana and C. hepaticum, rats act as effective spreaders of the human infective stage (eggs). For H. diminuta, G. neoplasticum and M. moniliformis, rats act as indirect reservoirs of the zoonoses since the eggs shed by the rats are infective for their insect intermediate hosts only. Medical practitioners need to be made aware of the range of parasites carried by rats, as there is a realistic likelihood that ill health currently caused by rat infestations may be misdiagnosed.

Contribution of Healthy Chickens to Antimicrobial-Resistant Escherichia coli Associated with Human Extraintestinal Infections in Egypt.

Chickens are considered potential reservoirs for human extraintestinal infections with pathogenic Escherichia coli. However, information about genetic relatedness between E. coli from healthy chickens and human patients is still limited. In this study, clinical samples from patients with extraintestinal infections and healthy broiler chickens were collected from geographically related locations in Egypt during the 2nd half of 2015. The recovered isolates were tested for susceptibility against β-lactam antimicrobials and screened for the presence of extended-spectrum β-lactamases (ESBLs) and virulence genes; clonal and phylotypes were also determined. Forty-eight percent (48/100) and 31.3% (50/160) of human and chicken samples were positive for E. coli, respectively. Although only 4% (2/50) of the chicken isolates were resistant to the tested β-lactams, over 58% of human E. coli isolates (28/48) exhibited resistance to cefotaxime. For β-lactamases, 52.1%, 33.3%, 20.8%, and 6.25% of human E. coli were positive for blaCTX-M, blaTEM, blaOXA, and blaCMY, while blaTEM, blaOXA, and blaCMY were found in 32%, 4%, and 34% of chicken isolates, respectively. Low frequencies of virulence genes within human and chicken E. coli isolates were detected by PCR. The majority of E. coli isolates harboring β-lactam resistance genes from human and chicken sources belonged to phylogroup C and B1, respectively. Using pulsed-field gel electrophoresis (PFGE), some E. coli grouped based upon source; however, most clusters contained isolates from both humans and chickens. The above findings suggest that although no single clone appeared to be circulating among E. coli isolates from human and chicken, some shared characteristics exist among isolates from both sources. Increased study will aid to track the dissemination of β-lactam-resistant E. coli from healthy chickens to humans for implementation of effective intervention strategies.

Ruminant and chicken: important sources of campylobacteriosis in France despite a variation of source attribution in 2009 and 2015

Pathogen source attribution studies are a useful tool for identifying reservoirs of human infection. Based on Multilocus Sequence Typing (MLST) data, such studies have identified chicken as a major source of C. jejuni human infection. The use of whole genome sequence-based typing methods offers potential to improve the precision of attribution beyond that which is possible from 7 MLST loci. Using published data and 156 novel C. jejuni genomes sequenced in this study, we performed probabilistic host source attribution of clinical C. jejuni isolates from France using three types of genotype data: comparative genomic fingerprints; MLST genes; 15 host segregating genes previously identified by whole genome sequencing. Consistent with previous studies, chicken was an important source of campylobacteriosis in France (31–63% of clinical isolates assigned). There was also evidence that ruminants are a source (22–55% of clinical isolates assigned), suggesting that further investigation of potential transmission routes from ruminants to human would be useful. Additionally, we found evidence of environmental and pet sources. However, the relative importance as sources varied according to the year of isolation and the genotyping technique used. Annual variations in attribution emphasize the dynamic nature of zoonotic transmission and the need to perform source attribution regularly.

Detection of anti-Salmonella antibodies in food animals of Nagpur region by In-house ELISA

Salmonella is a widespread enteric pathogen of many animal species, including mammals, birds, insects, reptiles and humans. It is an opportunistic bacterium, infecting immunosuppressed animal and takes over lead in the absence of other competing gut bacteria. Salmonella Typhimurium DT104, is of particular public health concern. In the present study sero-survey based on in-house enzyme-linked immunosorbent assays (ELISAs) have been attempted to study prevalence of anti-Salmonella antibodies among food animals by employing whole cell (WC) and lipopolysachharide (LPS) antigens. A total of 200 sera samples comprising 50 each from slaughter male cattle, buffaloes, goats and pigs were included in a study. WC-ELISA recorded 24% (cattle), 6% (buffalo), 68% (goat) and 74% (pigs) seropositivity for Salmonella whereas LPS-ELISA estimated seroprevalence of 8%, 0%, 56% and 40% among cattle, buffaloes, goats and pigs respectively. Though the results of ELISAs based on two antigens are not parallel, but the fact of presence of anti-Salmonella antibodies among food animals cannot be denied which is important from public health point of view. More comprehensive studies on livestock salmonellosis are required for further analysis of the bacterial reservoir for human infection. The usefulness of these two antigens as the diagnostic markers for detecting anti-Salmonella antibodies requires more study.

Predicting the likelihood and intensity of mosquito infection from sex specific Plasmodium falciparum gametocyte density.

Understanding the importance of gametocyte density on human-to-mosquito transmission is of immediate relevance to malaria control. Previous work (Churcher et al., 2013) indicated a complex relationship between gametocyte density and mosquito infection. Here we use data from 148 feeding experiments on naturally infected gametocyte carriers to show that the relationship is much simpler and depends on both female and male parasite density. The proportion of mosquitoes infected is primarily determined by the density of female gametocytes though transmission from low gametocyte densities may be impeded by a lack of male parasites. Improved precision of gametocyte quantification simplifies the shape of the relationship with infection increasing rapidly before plateauing at higher densities. The mean number of oocysts per mosquito rises quickly with gametocyte density but continues to increase across densities examined. The work highlights the importance of measuring both female and male gametocyte density when estimating the human reservoir of infection.

Outbreaks of abortions by Coxiella burnetii in small ruminant flocks and a longitudinal serological approach on archived bulk tank milk suggest Q fever emergence in Central Portugal.

Q fever is a worldwide zoonotic infectious disease caused by Coxiella burnetii and sheep and goats are known to be the main reservoir for human infection. This study describes the epidemiological and laboratory findings of C.burnetii outbreaks affecting sheep and goat flocks and also provides the results of a prospective serosurvey in bulk tank milk samples to assess C.burnetii circulation in a population of sheep living in close contact to the human population in Central Portugal. In the epizooties, C.burnetii was identified in tissues of the resulting abortions by qPCR. As for the serological survey, 10.2% (95%CI: 4.5-19.2) of the 78 bulk tank milk samples collected in 2015 presented IgG antibodies against C.burnetii. The same farms were visited and sampled in 2016 and 25.6% (95%CI: 16.4-36.8) were positive. This steep increase in the number of anti-C.burnetii farms between the 2015 and 2016 collections showed to be statistically significant (p=0.020) and is strongly suggestive of Q fever emergence in Central Portugal. Measures on animal health and on disease spread control to the human population should be considered.

Modeling the impact of Plasmodium falciparum sexual stage immunity on the composition and dynamics of the human infectious reservoir for malaria in natural settings.

Malaria transmission remains high in Sub-Saharan Africa despite large-scale implementation of malaria control interventions. A comprehensive understanding of the transmissibility of infections to mosquitoes may guide the design of more effective transmission reducing strategies. The impact of P. falciparum sexual stage immunity on the infectious reservoir for malaria has never been studied in natural settings. Repeated measurements were carried out at start-wet, peak-wet and dry season, and provided data on antibody responses against gametocyte/gamete antigens Pfs48/45 and Pfs230 as anti-gametocyte immunity. Data on high and low-density infections and their infectiousness to anopheline mosquitoes were obtained using quantitative molecular methods and mosquito feeding assays, respectively. An event-driven model for P. falciparum sexual stage immunity was developed and fit to data using an agent based malaria model infrastructure. We found that Pfs48/45 and Pfs230 antibody densities increased with increasing concurrent gametocyte densities; associated with 55–70% reduction in oocyst intensity and achieved up to 44% reduction in proportions of infected mosquitoes. We showed that P. falciparum sexual stage immunity significantly reduces transmission of microscopic (p < 0.001) but not submicroscopic (p = 0.937) gametocyte infections to mosquitoes and that incorporating sexual stage immunity into mathematical models had a considerable impact on the contribution of different age groups to the infectious reservoir of malaria. Human antibody responses to gametocyte antigens are likely to be dependent on recent and concurrent high-density gametocyte exposure and have a pronounced impact on the likelihood of onward transmission of microscopic gametocyte densities compared to low density infections. Our mathematical simulations indicate that anti-gametocyte immunity is an important factor for predicting and understanding the composition and dynamics of the human infectious reservoir for malaria.

A versatile and sensitive lateral flow immunoassay for the rapid diagnosis of visceral leishmaniasis.

Visceral leishmaniasis (VL) is a zoonotic infectious disease with a severe impact on humans and animals. Infection is transmitted by phlebotomine sand flies, and several domestic and wild mammals act as reservoirs for the infection, so the prompt detection of infected hosts is crucial to preventing and controlling the spread of the disease and its transmission to humans. A rapid and portable tool for VL diagnosis based on the lateral flow immunoassay (LFIA) technology is described herein. The device exploits a highly specific chimeric recombinant antigen as the recognition element for capturing anti-leishmanial antibodies, and protein A labelled with gold nanoparticles as the signal reporter. The LFIA shows excellent diagnostic sensitivity (98.4%), specificity (98.9%), and agreement with serological reference methods for diagnosing canine VL. The long-term stability of the LFIA device was confirmed based on six months of storage at room temperature or 4°C, and the qualitative response of the device was not affected by limited thermal stress. The use of the broadly specific protein A means that the LFIA can be readily adapted to diagnose VL in dogs (the main reservoir for human infection) and other mammals, thus further assisting efforts to control the spread of VL. Graphical abstract A rapid and portable diagnostic tool for visceral leishmaniasis (VL) based on lateral flow immunoassay (LFIA) technology. The presence of anti-leishmanial antibodies is revealed through the binding of these antibodies to a highly specific chimeric antigen. Employing a broadly specific signal reporter (protein A labelled with gold nanoparticles) enables the LFIA to be easily adapted to diagnose VL in different animals.

Surface and Extracellular Proteome of the Emerging Pathogen Corynebacterium ulcerans.

Corynebacterium ulcerans is an emerging pathogen, which is increasingly recognized as an etiological agent of diphtheria, but can also evoke ulcers of the skin and systemic infections in humans. Besides man, the bacteria can colonize a wide variety of different animals, including cattle and pet animals, which might serve as a reservoir for human infections. In this study, surface-located proteins and the exoproteome of two Corynebacterium ulcerans strains were analyzed, since these may have key roles in the interaction of the pathogen with host cells. Strain 809 was isolated from a fatal case of human respiratory tract infection, while strain BR-AD22 was isolated from a nasal swap of an asymptomatic dog. While a very similar pattern of virulence factors was observed in the culture supernatant and surface protein fractions of the two strains, proteome analyses revealed a higher stability of 809 cells compared to strain BR-AD22. During exponential growth, 17% of encoded proteins of strain 809 were detectable in the medium, while 38% of the predicted proteins encoded by the BR-AD22 chromosome were found. Furthermore, the data indicate differential expression of phospholipase D and a cell wall-associated hydrolase, since these were only detected in strain BR-AD22.

Prevalence and multi-locus genotyping of Giardia duodenalis from goats in Shaanxi province, northwestern China

Giardia duodenalis (syn. Giardia lamblia, Giardia intestinalis) is an important zoonotic parasite that parasitizes the gastro-intestines of humans and animals, with diarrhea as the most common clinical symptom. The goat has been indicated as one of the most important reservoirs of G. duodenalis for humans. In the present study, we investigated the prevalence and genetic diversity of G. duodenalis in goats in Shaanxi province, northwestern China. A total of 1311 faecal specimens were examined, and the overall prevalence was 7.1% (93/1311). Although all the meat, cashmere and dairy goats were positive for infection, the highest prevalence was found in cashmere goats (10.2%), followed by dairy (9.4%) and meat goats (2.0%). Negative correlation between age and prevalence was also observed, and the highest prevalence was detected in 0–2-month goats. Genetic analysis showed the presence of three assemblages, including two zoonotic (A and B) and one animal-adapted assemblage E, with E as the prevalent assemblage found in all breeds of positive goats. The zoonotic assemblage A was found in Guanzhong dairy and Shanbei cashmere goats, but B was only detected in Boar goats. Additionally, mixed assemblages E and A were also identified in two cashmere goats. Multi-locus genotyping (MLST) using the gene loci of the triosephosphate isomerase (tpi), b-giardin (bg) and glutamate dehydrogenase (gdh) identified four novel multi-locus genotypes (MLGs), including two assemblage E MLGs and two assemblage A MLGs. These results suggested that Boar, Guanzhong dairy and Shanbei cashmere goats in Shaanxi province would be potential reservoirs for human infections in this area, and this study also provided basic data for controlling G. duodenalis infection in goats as well as other hosts.

Epidemiological characteristics and post-exposure prophylaxis of human rabies in Chongqing, China, 2007\u20132016

BackgroundAccording to the global framework of eliminating human rabies, China is responding to achieve the target of zero human death from dog-mediated rabies by 2030. Chongqing is the largest municipality directly under central government in China. We described the epidemiological characteristics and post-exposure prophylaxis (PEP) of human rabies in this area, in order to provide a reliable epidemiology basis for further control and prevention of human rabies.MethodsThe most updated epidemiological data for human rabies cases from 2007 to 2016 in Chongqing were collected from the National Disease Reporting Information System. A standardized questionnaire was applied to the human rabies cases or family members of cases as proxy to investigate the PEP situation.ResultsA total of 809 fatal human rabies cases were reported in Chongqing from 2007 to 2016. There was a trend of gradual annual decline about number of cases from 2007 to 2013, followed by stable levels until 2016. Rabies was mostly reported in summer and autumn; a majority of cases were noted in farmers (71.8%), especially in males (65.3%). The cases aged 35–74 and 5–14 years old accounted for 83.8% of all the cases. We collected information of 548 human rabies cases’ rabies exposure and PEP situation. Of those, 95.8% of human rabies cases were victims of dog bites or scratch, and 53.3% of these dogs were identified as stray dogs. Only 4.0% of the domestic dogs were reported to have been vaccinated previously. After exposure, 87.8% of the 548 human rabies cases did not seek any medical services. Further investigation showed that none of the 548 cases received timely and properly standardized PEP.ConclusionHuman rabies remains a major public health problem in Chongqing, China. Dogs are the main reservoir and source of human rabies infection. Unsuccessful control of canine rabies and inadequate PEP of cases might be the main factors leading to the serious human rabies epidemic in this area. An integrated “One Health” approach should be encouraged and strengthened in this area; with combined effort it would be possible to achieve the elimination of human rabies in the expected date.

Diagnosis of Leptospira spp. Infection in Sheep Flocks in the State of Mato Grosso, Brazil

Background: Leptospirosis has a worldwide distribution with high social and economic impact. It is caused by a variety of Leptospira spp. serovars, particularly in tropical regions. Various species of animals can be affected by Leptospira spp. including cattle, horses, sheep, goats and swine, and can act as a reservoir for human infection. In Brazil, sheep leptospirosis has been diagnosed in a variety of States, however, little is known about sheep flocks of Mato Grosso. Considering the marked growth of sheep industry in Mato Grosso State in past recent years, this study aimed to evaluate the frequency of serologically positive sheep for Leptospira spp. serovars in the State of Mato Grosso (Brazil).Materials, Methods &amp; Results: Blood samples of 346 sheep, which belonged to 16 sheep flocks of the medium northern region of Mato Grosso was obtained by jugular vein puncture. Serum was obtained by blood centrifugation and stored at -20°C until the test to be performed. The diagnosis was performed using the microscopic agglutination test. Serovars Australis, Autumnalis, Bataviae, Bolívia, Castelonis, Celledoni, Grippotyphosa, Hardjo, Hardjobovis, Hebdomadis, Icterohaemorrhagiae, Javanica, Lagoa, Norma, Panama, Pomona, Sejroe, Shermani, Szwajizak, and Wolffi were tested. Reactions were considered positive with minimum titration of 1:100. Considering all serovars, 54.9% of sheep were positive, and the serovar more frequently detected was Celledoni (22.8%), followed by Javanica (19.4%), Castellonis (16.5%), and Norma (15.3%), with predominance of titration of 100 for these serovars, while only one sheep had a titration of 1:800 detected for serovar Hardjo. All flocks (100%) were positive (at least one positive animal), with the frequency of animals positive to Leptospira spp. varying of 31.3% to 79.2% in flocks.Discussion: Infection for Leptospira spp. in humans has a large social and sanitary impact. Under an animal health perspective, beyond sanitary impact, leptospirosis have a large economic impact and can act as important reservoirs for Leptospira spp. for human infection, especially in tropical conditions, which favor the persistence of agent in the environment. The occurrence of sheep leptospirosis has been diagnosed in several States of Brazil as Rio Grande do Sul, Paraíba, Rio de Janeiro, São Paulo and Maranhão, with frequency of herds positive for Leptospira spp. varying of 5.4% to 47.4%, however, the frequency of positive sheep in this study was higher than these previous reports in other Brazilian States. The most frequent serovar in sheep flocks have a great importance for prophylactic control. However, there were identified as main frequent serovar Celledoni and Javanica, which are considered unusual in sheep, and indicates a peculiar profile of ovine serovars for the region. Considering de high frequency of positive farms (100%) in Mato Grosso and the lack of studies about the occurrence of leptospirosis in this region, our results suggest the occurrence of risk factors that can favor the dispersion and survival of agent. Contact of the sheep evaluated in this study with other animal species such as cattle, dogs, and horses that can serve as a source for sheep infection or may become contaminated from sheep. Then, the profile of sheep infection by Leptospira spp. in the State of Mato Grosso has a peculiar profile of serovars, with high frequency of infection of animals and herds.

Prevalence and Molecular Characterization of Giardia duodenalis in Calves in Turkey

Background: Giardia duodenalis (G. duodenalis) is an ubiquitous, flagellated intestinal protozoan with major public health significance worldwide. Limited data are available on the epidemiology of G. duodenalis in dairy cattle from Turkey. Determining the zoonotic potential of the Giardia infection requires molecular characterization. The aim of the present study was to investigate the prevalence and to molecularly characterize G. duodenalis in calves less than three months of age in Aydin, Aegean region of Turkey.Materials, Methods &amp; Results: The study was conducted on different dairy farms in the south-western part of the Turkey, Aegean Region, Aydin. A total of 198 Holstein Friesian calves less than three months of age, of both sexes were enrolled into the study. Faecal samples from each calf were collected manually from the rectum using a disposable latex glove. The consistency of collected samples was recorded as diarrhoeic or non-diarrhoeic. Diagnosis of G. duodenalis infection was made microscopically by detection of cysts in the faecal samples. One hundred and sixteen (58.5%) of the 198 faecal samples were diarrheic. Giardia cysts were found in 27 (23.28%) of the diarrheic samples and in 8 (9.76%) of nondiarrheic samples (P &lt; 0.05). The overall prevalence of giardiosis in calves was determined as 17.67%. The prevalence of Giardia genotypes was identified by DNA sequence analysis of the beta-giardin gene for every PCR positive sample. The beta-giardin nested PCR assay was revealed assemblage A and sub-genotype A3 was detected in all of 35 samples (100%).Discussion: The highest prevalence of Giardia infection in calves is reported at the age between 1 and 6 months, and the prevalence shows decreased rate from the age of 6 months. The present study was conducted in Aydin, a province of south-western Turkey in the Aegean Region, and the overall prevalence from a total of 198 dairy calves was 17.67%. The prevalence rate in calves with diarrhoea was higher and reached up to 23.28%, whereas it was 9.76% in non-diarrhoeic calves. A prevalence study with molecular characterization of G. duodenalis isolates in cattle has not yet been reported from Turkey. Molecular studies have shown that mostly assemblage E predominates in cattle, but recent studies denoted that assemblage A is increasingly being detected and might be more widespread than expected before. In the present study, Giardia positive samples identified with a beta-giardin nested PCR assay. The sub-genotype A3 was identified in all samples. The same sub-genotype was identified in human and dog samples from different countries. Furthermore, sub-genotype A3 was found in humans and dogs from Turkey. In this context, results of the present study suggested an important role of calves as potential reservoirs of human infections in Turkey. In conclusion, epidemiological data revealed that G. duodenalis infection is frequent in calves with diarrhoea in Aydin, Turkey. The presence of the potentially zoonotic sub-genotype A3 and high prevalence of Giardia infection in diarrheic calves indicated the importance of treatment and necessary preventative measures. Further studies in human and animal populations living in this region are warranted regarding the zoonotic epidemiology of Giardia duodenalis.

Molecular Characterization of Enterocytozoon bieneusi in Wild Carnivores in Spain.

Microsporidia comprises a diverse group of obligate intracellular parasites that infect a broad range of invertebrates and vertebrates. Among Microsporidia, Enterocytozoon bieneusi is the most frequently detected species in humans and animals worldwide bringing into question the possible role of animal reservoirs in the epidemiology of this pathogen. Although E.bieneusi is an emerging zoonotic pathogen able to infect many domestic and wild mammals that could act as reservoir of infection for humans and other animals, only few studies have documented its occurrence in wild carnivores. To determine the occurrence of E.bieneusi in wild carnivores, we examined 190 wild carnivores collected from different locations in Spain. Twenty-five fecal samples (13.2%) from three host species (European badger, beech marten, and red fox) were E.bieneusi-positive by PCR. Nucleotide sequence analysis of the ITS region revealed a high degree of genetic diversity with a total of eight distinct genotypes including four known (PtEbIX, S5, S9, and WildBoar3) and four novel (EbCar1-EbCar4) genotypes identified. Phylogenetic analysis showed that the four novel genotypes (EbCar1-EbCar4), S5, S9, and WildBoar3 clustered within the previously designated zoonotic Group 1. Our results demonstrate that human-pathogenic genotypes are present in wild carnivores, corroborating their potential role as a source of human infection and environmental contamination.

Co-infection with Fasciola hepatica may increase the risk of Escherichia coli O157 shedding in British cattle destined for the food chain

Escherichia coli O157 is a zoonotic bacterium that can cause haemorrhagic diarrhoea in humans and is of worldwide public health concern. Cattle are considered to be the main reservoir for human infection. Fasciola hepatica is a globally important parasite of ruminant livestock that is known to modulate its host’s immune response and affect susceptibility to bacterial pathogens such as Salmonella Dublin. Shedding of E. coli O157 is triggered by unknown events, but the immune system is thought to play a part. We investigated the hypothesis that shedding of E. coli O157 is associated with F. hepatica infection in cattle. Three hundred and thirty four cattle destined for the food chain, from 14 British farms, were tested between January and October 2015. E. coli O157 was detected by immunomagnetic separation and bacterial load enumerated. F. hepatica infection status was assessed by copro-antigen ELISA. A significant association (p=0.01) was found between the log percent positivity (PP) of the F. hepatica copro-antigen ELISA and E. coli O157 shedding when the fixed effects of day of sampling and the age of the youngest animal in the group, plus the random effect of farm were adjusted for. The results should be interpreted cautiously due to the lower than predicted level of fluke infection in the animals sampled. Nevertheless these results indicate that control of F. hepatica infection may have an impact on the shedding of E. coli O157 in cattle destined for the human food chain.

Persistence of hepatitis E virus in the liver of non-viremic naturally infected wild boar.

Hepatitis E virus (HEV) is an emerging zoonotic pathogen with pigs and wild boar serving as reservoirs for human infection through direct contact with infected animals or the consumption of raw or undercooked pork products. The liver is considered the main target site of HEV replication in swine and an important organ in the pathogenesis of the disease. The aim of this study was to characterize the target liver cells for HEV entry in naturally infected wild boar and to evaluate the type and severity of the pathological changes in order to reach a better understanding of the hepatic pathogenic mechanisms involved in hepatitis E. In total, 58 livers from hunted wild boar were histopathologically evaluated. The presence of specific HEV antibodies in serum was determined by indirect ELISA. Immunohistochemistry was used for the detection of HEV antigen and Real time RT-PCR to detect HEV RNA in liver and serum. HEV seroprevalence in these animals was of 5.197% (CI95%: 1.77–14.14). By Real time RT-PCR, HEV was detected in the liver tissue of four wild boar (6.8%; CI95%: 2.7–16.4) and only one animal was also positive in serum (1.7%; CI95%: 0.3–9.1). The non-viremic animals naturally infected with HEV presented evidence of liver infection, mainly in Kupffer cells and liver sinusoidal endothelial cells, without apparent associated hepatitis lesions. This study supports the hypothesis that low viral titers may persist in the liver of non-viremic individuals, giving thus the possibility of consumption of contaminated liver of animals diagnosed as HEV-negative in serum. Further immunopathogenic studies are necessary to elucidate the mechanisms responsible for this process and to evaluate the protocols of HEV diagnosis in animals destined for human consumption.