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1.
The diversity of Cryptosporidium at species, subtype family and subtype level in diarrhoeic children was investigated in four provinces in South Africa. A total of 442 stool samples from children <5 years of age were collected under a large rotavirus surveillance programme and analysed by Ziehl–Neelsen acid‐fast staining. Fifty‐four (12.2%) were positive for Cryptosporidium, of which 25 were genotyped by polymerase chain reaction (PCR)–restriction fragment length polymorphism (RFLP) and DNA sequence analyses of the 18S rRNA gene. The majority of genotyped specimens were identified as C. hominis (76%), and a high genetic diversity was found with five different C. hominis subtype families (Ia, Ib, Id, Ie and If). Cryptosporidium parvum was found in 20% of the isolates, and three subtype families were identified (IIc, IIe and IIb), with subtype family IIc being the most common. One specimen was identified as C. meleagridis of the subtype family IIId. These results are in accordance with findings from other developing countries and report for the first time the presence in South Africa of C. meleagridis, various subtypes of C. parvum and the subtype family Ie of C. hominis. The results suggest that C. hominis and anthroponotic C. parvum subtypes are the major cause of cryptosporidiosis in South Africa. Further molecular studies are needed to better understand the epidemiology and public health importance of Cryptosporidium in humans in South Africa.  相似文献   

2.
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3.
Cryptosporidium spp. are common intestinal protozoan parasites that infect a wide range of hosts, including humans and livestock, worldwide. The objective of this study was to determine the prevalence of Cryptosporidium spp. in dairy calves in Prince Edward Island, Canada, and the potential for transmission of this parasite between dairy calves and humans. Fecal samples were collected from 183 dairy calves from 11 farms in Prince Edward Island. The prevalence of Cryptosporidium spp. infections in these animals was determined by examining for the presence of oocysts in the fecal samples, using immunofluorescence microscopy. Molecular characterization was done using a nested-PCR protocol to amplify fragments of the Cryptosporidium heat-shock protein 70 gene, followed by DNA sequencing. Ten calves (6.2%), representing 4 out of 11 farms tested, were positive for Cryptosporidium spp. DNA sequence analysis on five PCR positive samples demonstrated that Cryptosporidium parvum was the only species present in the calves tested, suggesting that there is a potential risk of zoonotic transmission between dairy calves and humans in this region.  相似文献   

4.
Abstract

AIM: To assess the occurrence of Cryptosporidium oocysts in faecal specimens from foals, and investigate an outbreak of neonatal cryptosporidiosis in foals revealed in the course of the study.

METHODS: Faecal specimens from foals received by a diagnostic veterinary laboratory in New Zealand between 2006 and 2007 were submitted to Massey University and tested microscopically for the presence of Cryptosporidium oocysts. The Cryptosporidium isolates in the oocyst-positive specimens were genetically identified to species level. In addition, specimen submission data from the participating laboratory for 2005–2007 were examined. In the course of the study, the identification of one Cryptosporidium-positive specimen triggered an on-farm investigation.

RESULTS: Twelve faecal specimens submitted by the participating laboratory between 2006 and 2007 were tested further, and three were positive for C. parvum. Specimen submission records indicated a total of 67 faecal specimens were tested for Cryptosporidium by the participating laboratory between 2005 and 2007; 12 (18%) were positive. The on-farm investigation on a broodmare farm revealed a high incidence of neonatal diarrhoea in foals; C. parvum was the only enteropathogen found in the faeces of 4/4 affected foals examined. The diarrhoea in all those foals was self-limiting, manifesting during the second week of life, resembling foal heat diarrhoea, and accompanied by a short but intense period of shedding oocysts.

CONCLUSIONS AND CLINICAL RELEVANCE: The fact that Cryptosporidium parasites were identified in 18% of faecal specimens from foals analysed for this agent in 2005–2007 by the participating laboratory indicated that infection with this agent in foals is not uncommon.

Collectively, the results of this and previous studies performed in New Zealand indicate C. parvum is a cause of diarrhoea in newborn foals, potentially accounting for a proportion of cases empirically diagnosed as foal heat diarrhoea. It is therefore advisable to take precautions when handling diarrhoeic foals, until this potentially zoonotic agent is ruled out in the laboratory.  相似文献   

5.
The study was conducted to determine the role of house flies, Musca domestica and Musca sorbens to carry Cryptosporidium species in natural environment and filth flies potential for contamination of food item they visited using acid‐fast stain technique. Cryptosporidium was identified from flies collected in dairy cow barns, butchery, market and defecating grounds. Musca domestica captured from dairy cow barns and M. sorbens from defecating ground were found carrying more oocyst of Cryptosporidium parvum. Oocyst load per fly for M. domestica and M. sorbens was 5.84 and 3.42, respectively. Flies’ population dynamics in each month had little relation to the monthly oocyst frequency, r = 0.06 and 0.02 for M. domestica and M. sorbens, respectively. Cryptosporidium species oocysts were isolated from frozen mango juice, which filth flies visited in dairy farm barn. Load of oocysts in the mango juice was dependent on time contact of flies with mango juice and more oocysts were recovered (P < 0.05) in mango juice samples accessed by filth flies for longer period. Role of filth flies to carry and deposit Cryptosporidium species oocyst for development of food‐borne cryptosporidiosis is signified.  相似文献   

6.
Molecular epidemiology of Cryptosporidium subtypes in cattle in England   总被引：1，自引：0，他引：1  
Samples of Cryptosporidium spp., collected in a cross-sectional study of calves (median age 26 days) from 41 farms in Cheshire, UK, underwent molecular typing. The aim was to determine naturally occurring species/genotypes and to investigate transmission pathways within a local area. Of 60 positive samples, 54 were sequenced at an 18S rRNA locus and 51 were typed at a GP60 locus. C. parvum was identified in 50 samples, three cases were C. bovis and one was Cryptosporidium deer-like genotype. Six GP60 subgenotypes were identified. One subgenotype (IIaA15G2R1) was highly prevalent throughout the study area. A single subgenotype was identified on 20/22 farms. Two subgenotypes were found on 2/22 farms. The spatial scan statistic detected a cluster of subgenotype IIaA15G2R1 comprising seven farms. This suggests local transmission of the parasite between farms. As most of the isolates detected were the potentially zoonotic C. parvum allele IIa, intervention strategies should be considered to reduce the threat to public health. Biosecurity measures may reduce transmission between farms and result in lower levels of environmental contamination.  相似文献   

7.
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8.
The aim of this study was to determine the prevalence, variability with host age, and the genotypes of species of Cryptosporidium in cattle from 15 dairy farms in Qazvin province, Iran. Fecal samples, collected from 272 cattle during May 2006 to December 2007, were characterized microscopically. Oocysts from 51 positive samples were analyzed using PCR assay of 18S SSU rRNA, restriction fragment length polymorphism (RFLP) and sequencing. We identified 72.6% of the positive samples as Cryptosporidium parvum, 17.7% as Cryptosporidium andersoni, 7.8% as Cryptosporidium bovis and 1.9% as a novel genotype of C. parvum possessing a single mutation on MboII restriction. An infection rate of 19.5% of C. parvum among 174 pre-weaned calves was significantly higher than the 3.1% among 98 post-weaned calves (P < 0.0006). This is the first report of C. bovis and the new subgenotype of C. parvum in Iranian cattle.  相似文献   

9.
This study was undertaken to investigate the occurrence and public health significance of Cryptosporidium species/genotypes and subtypes in a newborn lambs. A total of 175 diarrheic fecal samples from lambs (younger than 21 days) were collected in seven sheep flocks located in western Romania, and were microscopically examined for the presence of Cryptosporidium oocysts after staining with modified Ziehl–Neelsen technique. Twenty-four (13.7%) fecal samples were tested Cryptosporidium positive by microscopy and were subjected for molecular characterization. All positive samples were successfully amplified through a nested polymerase chain reaction (PCR) of the small subunit (SSU) rRNA gene (18S). Cryptosporidium species were determined by restriction fragment length polymorphism (RFLP) analysis of the secondary PCR products using the conventional SspI and VspI restriction enzymes. The identified species were: Cryptosporidium parvum (20/24), C. ubiquitum (2/24) and C. xiaoi (2/24), respectively. PCR-RFLP results for C. ubiquitum and C. xiaoi isolates were confirmed by DNA sequencing. Subsequently, subtyping of seven randomly selected C. parvum isolates, based on sequence analysis of the GP60 gene, revealed the presence of five different subtypes (IIaA17G1R1, IIaA16G1R1, IIdA20G1, IIdA24G1 and IIdA22G2R1) belonging in two zoonotic subtype families (IIa and IId). These findings may suggest the potential role of the newborn lambs as a source for human cryptosporidiosis. This is the first published report about the presence of C. ubiquitum and C. xiaoi in lambs from Romania.  相似文献   

10.
The objectives of this study were to determine the individual and herd-level prevalence and genotype of Cryptosporidium and to identify putative risk factors associated with Cryptosporidium spp. infections in water buffaloes in northeast Thailand. Fecal samples from 600 water buffaloes of 287 farms in six provinces were collected and tested using DMSO-modified acid-fast staining and polymerase chain reaction. The overall prevalence of Cryptosporidium infections in buffaloes was 5.7 and 8.7 % among individual animals and herds, respectively. The provinces with highest infected Cryptosporidium were located in the Sakon Nakhon Basin in the northern part of the region. In addition, higher herd prevalence was observed among farms with more than five buffaloes (30 %) than those with five or less animals (16.2 %). Thirty (88.2 %) of the 34 Cryptosporidium-positive samples were Cryptosporidium parvum and four (11.8 %) were Cryptosporidium ryanae.  相似文献   

11.
In this study, we investigated the presence of Cryptosporidium in 171 faecal samples from reptiles commonly used as pet animals. These include lizards belonging to the genera Eublepharis, Pogona, Chlamydosaurus, Hemiteconyx, Teratoscincus, Tiliqua, Iguana, and Chamaeleo, snakes of the genera Lampropeltis, Elaphe, Python, Boa and Corallus, and tortoises belonging to the genera Testudo and Kinixys. Cryptosporidium oocysts were detected by immunofluorescence using a commercially available kit and cryptosporidial DNA by amplification of a polymorphic fragment of the 18S rDNA and the HSP70 locus.Cryptosporidium was detected in 38.6% and 25.1% of the samples analysed by immunofluorescence and PCR, respectively. Molecular characterisation of the isolates confirmed that C. serpentis and C. varanii (syn. C. saurophilum) are the main species involved in infection in pet reptiles but also showed the presence of C. parvum and C. muris, as well as other species or genotypes of this parasite including the Cryptosporidium mouse genotype and Cryptosporidium tortoise genotype previously described in reptiles. In addition, a Cryptosporidium sp. was isolated from a chameleon and a python.  相似文献   

12.
To understand the molecular characteristics of Cryptosporidium species contaminating rivers, water treatment plants and abattoirs in Ibadan Nigeria, water samples were obtained from ten rivers used for household and agricultural purposes, three major functional water treatment plants and three major abattoirs located within Ibadan metropolis during dry and rainy seasons between November, 2016 to October, 2017. Obtained samples were examined for Cryptosporidium oocysts using microscopy after using modified formalin–ether concentration method and modified acid-fast staining. Cryptosporidium oocysts were detected in samples from five rivers with mean oocyst count/field ranging from 7.70 ± 0.57–1.34 ± 0.57, oocysts were also detected in samples from two abattoirs with mean oocyst count/field ranging from 4.60 ± 0.33–2.50 ± 0.33. Genomic DNA were extracted from microscopy positive river and abattoir samples using sucrose gradient purification method and genotypes and subtypes of parasites were detected by nested PCR amplification and nucleotide sequence analysis of both 18S rRNA and 60-kDa glycoprotein (gp60) genes. Cryptosporidium parvum, C. muris and C. fragile were the only genotypes detected in some river samples, while gp60 gene sequence analysis showed that the C. parvum strain detected was subtype IIa. This study provides evidence that rivers used for household and agricultural purposes in studied area may be potential reservoirs and infection sources for Cryptosporidium species and zoonotic subtypes of public health importance.  相似文献   

13.
A total of 4338 faecal samples, 135 of sows, 3368 of pre‐weaned and 835 of post‐weaned piglets from eight farms in South Bohemia, Czech Republic were collected and examined for Cryptosporidium infection. No sow, but 5.7% pre‐weaned and 24.1% post‐weaned piglets were positive for Cryptosporidium infection. No relationship was found between diarrhoea and Cryptosporidium infection in any of the different age groups (pre‐ and post‐weaned piglets). Four piglets, which were sporadically shedding cryptosporidia in faeces, were necropsied. Neither clinical signs of diarrhoea nor macroscopical changes were found. Histologically, a moderate infection of cryptosporidia was detected in the glandular epithelium along the large intestine, with predisposition to the ansa centralis of the colon. No inflammatory response in the lamina propria was observed. Cryptosporidia were also commonly found in the glandular epithelium of submucosal lymphoglandular complexes in the colon. Cryptosporidium isolates from all farms were identified as Cryptosporidium suis using molecular markers (SSU rRNA). All of the C. suis strains obtained were larger [6.2 (6.0–6.8) × 5.5 (5.3–5.7) μm] than any isolate described so far [4.6 (4.4–4.9) × 4.2 (4.0–4.3) μm] and did not appear to be infective for neonatal BALB/c mice.  相似文献   

14.
《Veterinary parasitology》2015,207(1-2):144-148
This report is the first to describe Cryptosporidium infection in bamboo rats (Rhizomys sinensis). Ninety-two fresh fecal specimens were collected from a pet market in Ya’an City, China. One Cryptosporidium isolate from an asymptomatic host and two isolates from separate hosts with diarrhea were obtained by using Sheather's sucrose flotation technique and modified acid-fast staining. The Cryptosporidium spp. were genotyped by nested PCR and nucleotide sequencing of the small subunit rRNA (SSU rRNA), 70-kDa heat shock protein (HSP70), oocyst wall protein (COWP), and actin genes: isolates were identified as Cryptosporidium parvum with minor nucleotide differences at all four loci. Further subtyping was performed by PCR amplification and DNA sequence analysis of the 60-kDa glycoprotein (gp60) gene: two subtype families were detected, including a novel C. parvum subtype IIpA9 and a rare subtype IIoA13G1 (only reported in diarrheal patients of Sweden). Our results suggest that the bamboo rat is a reservoir host of C. parvum. Significantly, we discovered that the rare C. parvum subtype family IIo is also a zoonotic subtype and confirmed C. parvum subtype IIpA9 as a novel subtype family.  相似文献   

15.
Little is known about the diversity and public health significance of Cryptosporidium species in water buffaloes. In this study, we examined the distribution of Cryptosporidium spp. in water buffalo calves in Egypt. Rectal fecal specimens from 179 calves and 359 adults were screened microscopically for Cryptosporidium oocysts using modified Ziehl–Neelsen stain. Cryptosporidium spp. in 17 microscopy-positive specimens from calves were genotyped by DNA sequence analysis of the small-subunit rRNA gene, and Cryptosporidium parvum was subtyped by sequence analysis of the 60 kDa glycoprotein gene. Cryptosporidium ryanae was found in 10 specimens and C. parvum in 7 specimens, with the former belonging to the newly identified C. ryanae buffalo variant and the latter belonging to the subtypes IIdA20G1 (in 5 specimens) and IIaA15G1R1 (in 2 specimens). The prevailing occurrence of C. ryanae and the subtype family IId of C. parvum and the absence of C. bovis and C. andersoni represent some features of Cryptosporidium transmission in water buffaloes in Egypt.  相似文献   

16.
Cryptosporidium oocysts were found in 43 out of 77 calves from two farms in Iwate Prefecture and nine farms on Tanegashima Island, Kagoshima Prefecture, Japan. The DNA fragments of 18S ribosomal RNA (18S rRNA) gene were amplified by a nested PCR from 43 oocyst-positive as well as one oocyst-negative samples. All of them were precisely identified as C. parvum by analyzing the nucleotide sequences of the 18S rRNA gene. C. parvum oocyst-positive calves ranged in age from 6 to 13 days old and significantly have watery diarrhea (P<0.05). Sequences of the gene encoding the 60-kDa glycoprotein (GP60) in 43 Cryptosporidium oocyst-positive samples were identical to that of the zoonotic IIaA15G2R1 subtype. We therefore suggest that calves could be potential sources of C. parvum infections in humans.  相似文献   

17.
There are few epidemiologic studies on the role of dogs in zoonotic parasitic transmission in the Circumpolar North. The objectives of this study were to: (a) estimate the faecal prevalence of Giardia spp. and Cryptosporidium spp. in dogs; (b) investigate potential associations between the type of dog population and the faecal presence of Giardia spp. and Cryptosporidium spp.; and (c) describe the molecular characteristics of Giardia spp. and Cryptosporidium spp. in dogs in Iqaluit, Nunavut. We conducted two cross‐sectional studies in July and September 2016. In July, the team collected daily faecal samples for 3 days from each of 20 sled dogs. In September, the team collected three faecal samples from each of 59 sled dogs, 111 samples from shelter dogs and 104 from community dogs. We analysed faecal samples for the presence of Giardia spp. and Cryptosporidium spp. using rapid immunoassay and flotation techniques. Polymerase chain reaction (PCR) and sequencing of target genes were performed on positive faecal samples. Overall, the faecal prevalence of at least one of the target parasites, when one faecal sample was chosen at random for all dogs, was 8.16% (CI: 5.52–11.92), and for Giardia spp. and Cryptosporidium spp., prevalence was 4.42% (CI: 2.58–7.49) and 6.12% (CI: 3.88–9.53), respectively. The odds of faecal Giardia spp. in sled dogs were significantly higher than those in shelter and community dogs (OR 10.19 [CI: 1.16–89.35]). Sequence analysis revealed that 6 faecal samples were Giardia intestinalis, zoonotic assemblage B (n = 2) and species‐specific assemblages D (n = 3) and E (n = 1), and five faecal samples were Cryptosporidium canis. Giardia intestinalis is zoonotic; however, Cryptosporidium canis is rare in humans and, when present, usually occurs in immunosuppressed individuals. Dogs may be a potential source of zoonotic Giardia intestinalis assemblage B infections in residents in Iqaluit, Nunavut, Canada; however, the direction of transmission is unclear.  相似文献   

18.
In a cross-sectional study of 633 pigs from 21 herds on Prince Edward Island, Canada (PEI), the prevalence of infection with Cryptosporidium and Giardia, and the genotypes and species of isolates were determined in order to establish the zoonotic potential of pigs in this region. As determined by direct immunofluorescence microscopy (DFA), 18 herds (86%) and 163 animals (26%; 95% CI: 22-29%) tested positive for Cryptosporidium, while just 3 herds (14%) and 6 animals (1%; 95% CI: 0.4-2%) tested positive for Giardia. Cryptosporidium spp. isolates were detected in 39% (95% CI: 34-44%) of weanlings (1-3 months of age) and 9% (95% CI: 6-13) of sows (>8 months of age). Molecular characterization using the 18S rDNA and HSP70 gene fragments revealed the presence of Cryptosporidium sp. pig genotype II, C. suis, C. parvum, and Cryptosporidium sp. mouse genotype. Among the 113 isolates of Cryptosporidium spp. successfully genotyped, pig genotype II (61%) predominated, with C. suis (36%) being the next most prominant isolate. C. parvum (2%; two isolates) and Cryptosporidium sp. mouse genotype (0.9%; one isolate) were only occasionally isolated. The only two Cryptosporidium-positive genotyped isolates from sows included one each of C. suis and Cryptosporidium sp. pig genotype II.All but one of the six Giardia positive isolates were detected in weanling pigs. None of the Giardia-positive isolates was amenable to PCR. This study demonstrates that Cryptosporidium spp. are highly prevalent in pigs on PEI, Canada, are found mostly in weanlings (1-3 months of age). Furthermore, the pigs are primarily infected by the host-specific genotypes and species, Cryptosporidium sp. pig genotype II and C. suis, whereas the zoonotic C. parvum is rare. Giardia duodenalis is only occasionally found in pigs. These findings suggest that domestic pigs on PEI, Canada, likely do not pose a significant health risk to humans from these parasites.  相似文献   

19.

The microbiological quality of 118 samples of traditional Chinese food from restaurants and take-away establishments in the provinces of Padua, Treviso, and Venice was examined (April–July, 2008). These food items included various ready-to-eat products. The microbiological quality of the majority of these food items was acceptable; only 12% of samples had values greater than or equal to 6 log CFU/g (eight items were salads) and 19% of samples had values greater than 500 CFU fecal coliforms/g (p < 0.01 to 0.001). The Aw lower values were in sauces (0.839), but were greater than 0.95 in other food sources. No pathogens, such as Salmonella spp. or Listeria monocytogenes, were detected, but Bacillus cereus and coagulase-positive Staphylococcus were both identified. Thus, although final heating reduces the levels of microorganisms present in foods, it does not inactivate any toxins produced by such organisms.

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20.
The objective of this study was to investigate the occurrence of Cryptosporidium spp. and Giardia spp. in a public water‐treatment system and to relate the results to physical, chemical, bacteriological and climate parameters. From March to September 2006, 30 samples, 15 of raw water and 15 of treated water, were examined by membrane filtration and direct immunofluorescence (Merifluor). For each sample, a volume of 1000 l was collected. Of the raw‐water samples, 26.6% were positive for Cryptosporidium (mean concentration of 0.15 oocysts/l), and 6.66% were positive for Giardia (concentration of 0.2 cysts/l); 13.33% of the samples were positive for both (mean concentrations of 0.06 oocysts/l and 0.026 cysts/l respectively). All the samples of treated water were negative. There was no correlation (P < 0.05) between the presence of protozoans in the raw water and the parameters measured. The finding of Giardia and Cryptosporidium in raw water indicates that the water sources are contaminated. Considering that giardiasis is prevalent in the population and that Cryptosporidium has recognized zoonotic potential, long‐term monitoring at critical points of the system is necessary to guarantee that the water will not be a vehicle for transmission of these protozoans.  相似文献   

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