Molecular characterization of human-pathogenic microsporidia and Cyclospora cayetanensis isolated from various water sources in Spain: a year-long longitudinal study

Molecular detection of Cyclospora in water, soil, vegetables and humans in southern Italy signals a need for improved monitoring by health authorities

To date, in Europe, there is scant information on the occurrence of Cyclospora in water from treatment plants and in humans, and no data are available on soil or fresh plant products. Here, we undertook the first molecular survey of Cyclospora in multiple biological matrices collected from the Apulia region of southern Italy. Samples of irrigation water from four municipal treatment plants, eight different types of vegetables or fruit (cucumber, lettuce, fennel, celery, tomato, melon, endive and chicory) and soil from the same farms on which these plants were grown, as well as faecal samples from humans living in the same region were tested by qPCR-coupled single-strand conformation polymorphism (SSCP) analysis and DNA sequencing. Cyclospora was detected in 15.5% of all 213 samples tested. Specifically, this protist was detected in (i) treated water (21.3% of 94 samples), well water (6.2% of 16), but not drinking water (0% of 3); (ii) soil (11.8% of 51 samples) and vegetables (12.2% of 49), with the highest prevalence (18.7%) on fennel; and (iii) human stools (27.5% of 40 samples). In environmental and food samples, Cyclospora was detected mainly in autumn and was significantly more prevalent in the faeces from humans of 40-50 years of age. This is the first comprehensive molecular survey of Cyclospora in environmental, food and human faecal samples in Europe. These data suggest that irrigation water, soil and vegetables might be contaminated by Cyclospora cayetanensis, which might represent a source of infection to humans in the study area and calls for monitoring by health authorities.

High Prevalence and Widespread Distribution of Zoonotic Enterocytozoon bieneusi Genotypes in Swine in Northeast China: Implications for Public Health

This study analyzed 563 fecal specimens of asymptomatic pigs from five cities of northeast China for the prevalence and genetic characteristics of Enterocytozoon bieneusi. The parasite was detected in 267 of 563 (47.4%) pigs by nested PCR of the ribosomal internal transcribed spacer (ITS). The differences in prevalence between preweaned (58.0%, 94/162) and growing pigs (39.6%, 114/288) and between weaned (52.2%, 59/113) and growing pigs are significant (p < 0.05). Genotypic typing and phylogenetic analysis facilitated identification of six human-pathogenic genotypes EbpC, O, CS-4, EbpA, Henan-IV, and PigEBITS5 and six potentially zoonotic genotypes EbpB, CC-1, CS-1, CS-3, CHN7, and CS-10. Genotypes CS-4 (32/35) and EbpC (3/35) from Harbin and Henan-IV (5/64) from Qiqihar determined in pigs herein represented the main causative agents of human microsporidiosis in Harbin. The most dominant genotype EbpC found in pigs from Daqing (35/65) and Qiqihar (a close neighbor to Daqing) (47/64) contributed significantly to human infections in Daqing. Genotype EbpC was also a leading E. bieneusi pathogen in humans, drinking water, and wastewater in central China. This study provided robust evidence that pigs could be an outstanding source of human microsporidiosis and water contamination in China.

Zoonotic and Potentially Host-Adapted Enterocytozoon bieneusi Genotypes in Sheep and Cattle in Northeast China and an Increasing Concern about the Zoonotic Importance of Previously Considered Ruminant-Adapted Genotypes

This study investigated fecal specimens from 489 sheep and 537 cattle in multiple cities in northeast China for the prevalence and genetic characteristics of Enterocytozoon bieneusi by PCR and sequencing of the ribosomal internal transcribed spacer. Sixty-eight sheep specimens (13.9%) and 32 cattle specimens (6.0%) were positive for E. bieneusi. Sequence polymorphisms enabled the identification of 9 known genotypes (BEB4, BEB6, CM7, CS-4, EbpC, G, I, J, and OEB1) and 11 new genotypes (NESH1 to NESH6 and NECA1 to NECA5). The genotypes formed two genetic clusters in a phylogenetic analysis, with CS-4, EbpC, G, NESH1 to NESH3, and NECA1 to NECA5 distributed in zoonotic group 1 and BEB4, BEB6, CM7, EbpI, J, OEB1, and NESH4 to NESH6 distributed in potentially host-adapted group 2. Nearly 70% of cases of E. bieneusi infections in sheep were contributed by human-pathogenic genotypes BEB6, CS-4, and EbpC, and over 80% of those in cattle were by genotypes BEB4, CS-4, EbpC, I, and J. The cooccurrence of genotypes BEB4, CS-4, EbpC, I, and J in domestic ruminants and children in northeast China and the identification of BEB6 and EbpC in humans and water in central China imply the possibility of zoonotic transmission. This study also summarizes E. bieneusi genotypes obtained from ruminants worldwide and displays their host ranges, geographical distributions, and phylogenetic relationships. The data suggest a host range expansion in some group 2 genotypes (notably BEB4, BEB6, I, and J) that were previously considered to be adapted to ruminants. We should be concerned about the increasing zoonotic importance of group 2 genotypes with low host specificity.

Cyclospora cayetanensis travels in tap water on Italian trains

Tap water samples from the toilets of an Italian national railway train were collected over a period of 10 months and tested for the presence of Cyclospora cayetanensis (C. cayetanensis) using EvaGreen® real-time polymerase chain reaction (RT-PCR) assay coupled with high resolution melting (HRM) analysis for protozoan detection and oocyst quantification. C. cayetanensis positive samples were detected in March, April, and May 2013, with the number of oocysts of 4, 5, and 11 per liter, respectively. This is the first finding of C. cayetanensis in water samples in Italy. The findings call for an improvement of hygiene and water safety by the Italian national railway company.

Occurrence, source, and human infection potential of Cryptosporidium and Enterocytozoon bieneusi in drinking source water in Shanghai, China, during a pig carcass disposal incident

In March 2013, thousands of domestic pig carcasses were found floating in the Huangpu River, a drinking source water in Shanghai, China. To investigate the impact of the pig carcass incident on microbial water quality, 178 river water samples were collected from the upper Huangpu River from March 2013 to March 2014. Samples were concentrated by calcium carbonate flocculation and examined for host-adapted Cryptosporidium and Enterocytozoon bieneusi by ploymerase chain reaction (PCR). Positive PCR products were sequenced to determine Cryptosporidium species and E. bieneusi genotypes. A total of 67 (37.6%) and 56 (31.5%) samples were PCR-positive for Cryptosporidium and E. bieneusi, respectively. The occurrence rates of Cryptosporidium and E. bieneusi in March 2013 (83.3%; 41.7%) and May 2013 (73.5%; 44.1%) were significantly higher than rates in later sampling times. Among the 13 Cryptosporidium species/genotypes identified, C. andersoni and C. suis were the most common species, being found in 38 and 27 samples, respectively. Seventeen E. bieneusi genotypes were found, belonging to 11 established genotypes (EbpC, EbpA, D, CS-8, PtEb IX, Peru 8, Peru 11, PigEBITS4, EbpB, G, O) and six new ones (RWSH1 to RWSH6), most of which belonged to pig-adapted Groups 1d and 1e. EbpC was the most common genotype, being found in 37 samples. The distribution of Cryptosporidium species and E. bieneusi genotypes suggest that dead pigs contributed significantly to Cryptosporidium and E. bieneusi contamination in the Huangpu River. Although most Cryptosporidium species found in river water were not major human pathogens, the majority of E. bieneusi genotypes detected were endemic in China. Data from this study should be useful in the development of strategies in addressing future contamination events in drinking water supplies.

Enterocytozoon bieneusi, giardia, and Cryptosporidium infecting white-tailed deer

Despite a white-tailed deer (WTD) population in the United States of approximately 32 million animals extremely little is known of the prevalence and species of the protists that infect these animals. This study was undertaken to determine the presence of potential human protist pathogens in culled WTD in central Maryland. Feces from fawns to adults were examined by molecular methods. The prevalence of Enterocytozoon bieneusi, Cryptosporidium, and Giardia was determined by PCR. All PCR-positive specimens were sequenced to determine the species and genotype(s). Of specimens from 80 WTD, 26 (32.5%) contained 17 genotypes of E. bieneusi. Four genotypes were previously reported (I, J, WL4, LW1) and 13 novel genotypes were identified and named DeerEb1-DeerEb13. Genotypes I, J, and LW1 are known to infect humans. Ten (12.5%) specimens contained the Cryptosporidium deer genotype, and one (1.25%) contained Giardia duodenalis Assemblage A. The identification zoonotic G. duodenalis Assemblage A as well as four E. bieneusi genotypes previously identified in humans suggest that WTD could play a role in the transmission of those parasites to humans.

Microsporidia detection and genotyping study of human pathogenic E. bieneusi in animals from Spain

Microsporidia are ubiquitous parasites infecting all animal phyla and we present evidence that supports their zoonotic potential. Fecal samples taken from domestic (cats and dogs), farm (pigs, rabbits and ostriches) and wild animals (foxes) from different provinces of Spain were evaluated for microsporidia infection by light microscopy and PCR. After Microsporidia species identification, E. bieneusi genotypes were additionally studied by sequence analysis of the ITS region. Eighty-five samples out of 159 exhibited structures that were compatible with microsporidia spores by Webeŕs stain with 37 of them being confirmed by PCR. Microsporidia species identified included E. bieneusi, E. intestinalis and A. algerae. We report the first diagnosis of E. intestinalis and E. bieneusi in ostriches and A. algerae in pigs. We also provide new information on the molecular characterization of E. bieneusi isolates both in rabbits and ostriches. All of the E. bieneusi genotypes identified belonged to the zoonotic group of genotypes (Group I) including genotypes A (dogs), I (pigs), D (rabbits and foxes) and type IV (ostriches). Our results demonstrate that microsporidia are present in domestic, farm and wild animals in Spain, corroborating their potential role as a source of human infection and environmental contamination.

Cystoisospora and cyclospora

PURPOSE OF REVIEW

The present review focuses on recent epidemiological and diagnostic advances in cystoisosporiasis and cyclosporiasis.

RECENT FINDINGS

Continuous outbreaks of these parasites occur worldwide. Sporadic cases in the United States are travel acquired, but also domestically acquired. New molecular diagnostic methods allow for accurate early diagnosis in humans, and might potentially decrease the burden of disease by detecting these parasites in vehicles of transmission.

SUMMARY

Better understanding of the epidemiology of Cyclospora cayetanensis and to a less extent to Cystoisospora belli has been gained recently. However, several gaps still remain in knowledge on the transmission and on mechanisms of persistent infection in immunosuppressed patients and prevention. New molecular methods might help in filling these gaps and in controlling transmission.

Host specificity and source of Enterocytozoon bieneusi genotypes in a drinking source watershed

To assess the host specificity of Enterocytozoon bieneusi and to track the sources of E. bieneusi contamination, we genotyped E. bieneusi in wildlife and stormwater from the watershed of New York City's source water, using ribosomal internal transcribed spacer (ITS)-based PCR and sequence analyses. A total of 255 specimens from 23 species of wild mammals and 67 samples from stormwater were analyzed. Seventy-four (29.0%) of the wildlife specimens and 39 (58.2%) of the stormwater samples from streams were PCR positive. Altogether, 20 E. bieneusi genotypes were found, including 8 known genotypes and 12 new ones. Sixteen and five of the genotypes were seen in animals and stormwater from the watershed, respectively, with WL4 being the most common genotype in both animals (35 samples) and stormwater (23 samples). The 20 E. bieneusi genotypes belonged to five genogroups (groups 1, 3, 4, and 7 and an outlier), with only 23/113 (20.4%) E. bieneusi-positive samples belonging to zoonotic genogroup 1 and 3/20 genotypes ever being detected in humans. The two genogroups previously considered host specific, groups 3 and 4, were both detected in multiple groups of mammals. Thus, with the exception of the type IV, Peru11, and D genotypes, which were detected in only 7, 5, and 2 animals, respectively, most E. bieneusi strains in most wildlife samples and all stormwater samples in the watershed had no known public health significance, as these types have not previously been detected in humans. The role of different species of wild mammals in the contribution of E. bieneusi contamination in stormwater was supported by determinations of host-adapted Cryptosporidium species/genotypes in the same water samples. Data from this study indicate that the host specificity of E. bieneusi group 3 is broader than originally thought, and wildlife is the main source of E. bieneusi in stormwater in the watershed.