首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.

Background

Whole genome sequencing (WGS) of Cryptosporidium spp. has previously relied on propagation of the parasite in animals to generate enough oocysts from which to extract DNA of sufficient quantity and purity for analysis. We have developed and validated a method for preparation of genomic Cryptosporidium DNA suitable for WGS directly from human stool samples and used it to generate 10 high-quality whole Cryptosporidium genome assemblies. Our method uses a combination of salt flotation, immunomagnetic separation (IMS), and surface sterilisation of oocysts prior to DNA extraction, with subsequent use of the transposome-based Nextera XT kit to generate libraries for sequencing on Illumina platforms. IMS was found to be superior to caesium chloride density centrifugation for purification of oocysts from small volume stool samples and for reducing levels of contaminant DNA.

Results

The IMS-based method was used initially to sequence whole genomes of Cryptosporidium hominis gp60 subtype IbA10G2 and Cryptosporidium parvum gp60 subtype IIaA19G1R2 from small amounts of stool left over from diagnostic testing of clinical cases of cryptosporidiosis. The C. parvum isolate was sequenced to a mean depth of 51.8X with reads covering 100 % of the bases of the C. parvum Iowa II reference genome (Bioproject PRJNA 15586), while the C. hominis isolate was sequenced to a mean depth of 34.7X with reads covering 98 % of the bases of the C. hominis TU502 v1 reference genome (Bioproject PRJNA 15585).The method was then applied to a further 17 stools, successfully generating another eight new whole genome sequences, of which two were C. hominis (gp60 subtypes IbA10G2 and IaA14R3) and six C. parvum (gp60 subtypes IIaA15G2R1 from three samples, and one each of IIaA17G1R1, IIaA18G2R1, and IIdA22G1), demonstrating the utility of this method to sequence Cryptosporidium genomes directly from clinical samples. This development is especially important as it reduces the requirement to propagate Cryptosporidium oocysts in animal models prior to genome sequencing.

Conclusion

This represents the first report of high-quality whole genome sequencing of Cryptosporidium isolates prepared directly from human stool samples.  相似文献   

2.
Iqbal A  Lim YA  Surin J  Sim BL 《PloS one》2012,7(2):e31139

Background

Currently, there is a lack of vital information in the genetic makeup of Cryptosporidium especially in developing countries. The present study aimed at determining the genotypes and subgenotypes of Cryptosporidium in hospitalized Malaysian human immunodeficiency virus (HIV) positive patients.

Methodology/Principal Findings

In this study, 346 faecal samples collected from Malaysian HIV positive patients were genetically analysed via PCR targeting the 60 kDa glycoprotein (gp60) gene. Eighteen (5.2% of 346) isolates were determined as Cryptosporidium positive with 72.2% (of 18) identified as Cryptosporidium parvum whilst 27.7% as Cryptosporidium hominis. Further gp60 analysis revealed C. parvum belonging to subgenotypes IIaA13G1R1 (2 isolates), IIaA13G2R1 (2 isolates), IIaA14G2R1 (3 isolates), IIaA15G2R1 (5 isolates) and IIdA15G1R1 (1 isolate). C. hominis was represented by subgenotypes IaA14R1 (2 isolates), IaA18R1 (1 isolate) and IbA10G2R2 (2 isolates).

Conclusions/Significance

These findings highlighted the presence of high diversity of Cryptosporidium subgenotypes among Malaysian HIV infected individuals. The predominance of the C. parvum subgenotypes signified the possibility of zoonotic as well as anthroponotic transmissions of cryptosporidiosis in HIV infected individuals.  相似文献   

3.
Inconsistent data exist on the distribution of zoonotic Cryptosporidium species and subtypes in sheep and goats in European countries, and few such data are available from Greece. In this study, 280 fecal specimens were collected from 132 diarrheic lambs and 148 diarrheic goat kids aged 4 to 15?days on 15 farms in northern Greece, and examined for Cryptosporidium spp. using microscopy of Ziehl-Neelsen-stained fecal smears. Cryptosporidium spp. in 80 microscopy-positive fecal specimens (39 from lambs and 41 from goat kids) were genotyped by PCR-RFLP analysis of the small subunit rRNA gene and subtyped by sequence analysis the 60?kDa glycoprotein gene. Among the 33 specimens successfully genotyped, C. parvum was found in 32 and C. xiaoi in one. Seven subtypes belonging to two subtype families (IIa and IId) were identified among the 29 C. parvum specimens successfully subtyped, including IIaA14G2R1 (1/29), IIaA15G2R1 (6/29), IIaA20G1R1 (7/29), IIdA14G2 (1/29), IIdA15G1 (9/29), IIdA16G1 (3/29), and IIdA23G1 (2/29). Lambs were more commonly infected with C. parvum IIa subtypes, whereas goat kids were more with IId subtypes. The results illustrate that C. parvum is prevalent in diarrheic lambs and goat kids in northern Greece and these animals could potentially play a role in epidemiology of human cryptosporidiosis.  相似文献   

4.
This study assessed the prevalence, species and subtypes of Cryptosporidium in goats from Guangdong Province, Hubei Province, Shandong Province, and Shanghai City of China. Six hundred and four fecal samples were collected from twelve goat farms, and the overall infection rate was 11.4% (69/604). Goats infected with Cryptosporidium were found in eleven farms across four provincial areas, and the infection rate ranged from 2.9% (1/35) to 25.0% (9/36). Three Cryptosporidium species were identified. Cryptosporidium xiaoi (45/69, 65.2%) was the dominant species, followed by C. parvum (14/69, 20.3%) and C. ubiquitum (10/69, 14.5%). The infection rate of Cryptosporidium spp. was varied with host age and goat kids were more susceptible to be infected than adult goats. Subtyping C. parvum and C. ubiquitum positive samples revealed C. parvum subtype IIdA19G1 and C. ubiquitum subtype XIIa were the most common subtypes. Other C. parvum subtypes were detected as well, such as IIaA14G2R1, IIaA15G1R1, IIaA15G2R1 and IIaA17G2R1. All of these subtypes have also been detected in humans, suggesting goats may be a potential source of zoonotic cryptosporidiosis. This was the first report of C. parvum subtypes IIaA14G2R1, IIaA15G1R1 and IIaA17G2R1 infecting in goats and the first molecular identification of C. parvum and its subtypes in Chinese goats.  相似文献   

5.
The identification and characterisation of Cryptosporidiumgenotypes and subtypes are fundamental to the study of cryptosporidiosis epidemiology, aiding in prevention and control strategies. The objective was to determine the genetic diversity ofCryptosporidium in samples obtained from hospitals of Rio de Janeiro, Brazil, and Buenos Aires, Argentina. Samples were analysed by microscopy and TaqMan polymerase chain reaction (PCR) assays forCryptosporidium detection, genotyped by nested-PCR-restriction fragment length polymorphism (RFLP) analysis of the 18S rRNA gene and subtyped by DNA sequencing of the gp60 gene. Among the 89 samples from Rio de Janeiro, Cryptosporidium spp were detected in 26 by microscopy/TaqMan PCR. In samples from Buenos Aires,Cryptosporidium was diagnosed in 15 patients of the 132 studied. The TaqMan PCR and the nested-PCR-RFLP detected Cryptosporidium parvum, Cryptosporidium hominis, and co-infections of both species. In Brazilian samples, the subtypes IbA10G2 and IIcA5G3 were observed. The subtypes found in Argentinean samples were IbA10G2, IaA10G1R4, IaA11G1R4, and IeA11G3T3, and mixed subtypes of Ia and IIa families were detected in the co-infections. C. hominis was the species more frequently detected, and subtype family Ib was reported in both countries. Subtype diversity was higher in Buenos Aires than in Rio de Janeiro and two new subtypes were described for the first time.  相似文献   

6.
Cryptosporidium spp. are enteric protozoan parasites that infect a wide range of hosts including humans, and domestic and wild animals. The aim of this study was to molecularly characterize the Cryptosporidium spp. found in calf faeces in Japan. A total of 80 pre-weaned beef and dairy calves' diarrhoeic faecal specimens were collected from nine different prefectures in Japan. A nested polymerase chain reaction targeting the small subunit 18S rRNA and GP60 genes were used to detect the Cryptosporidium genotypes and subtypes. 83.8% (67 out of 80) of the specimens were positive for Cryptosporidium spp.; Cryptosporidium was found in both beef and dairy calves. Cryptosporidium parvum was the predominant species, detected in 77.5% (31/40) of beef calves and 80% (32/40) of dairy calves. Cryptosporidium bovis was also detected, 5.0% (2/40) of dairy calves, and C. ryanae was also found 2.5% (1/40) of dairy calves. One mixed-species infection, 2.5% (1/40) was detected in a beef calf having C. parvum, and C. ryanae. We detected the most common subtype of C. parvum (i.e., IIaA15G2R1), as well as other subtypes (i.e., IIaA14G3R1, IIaA14G2R1, and IIaA13G1R1) that have not previously been detected in calves in Japan. Our results demonstrate the widespread diversity of Cryptosporidium infection in calves in Japan.  相似文献   

7.
The studies on Cryptosporidium infections of animals in Turkey mostly rely on microscopic observation. Few data are available regarding the prevalence of Cryptosporidium genotypes and subtypes infection. The aim of this study is to analyse the detection of Cryptosporidium genotypes and subtypes from young ruminants. A total of 415 diarrheic fecal specimens from young ruminants were examined for the Cryptosporidium detection by use of nested PCR of the small subunit ribosomal RNA (SSU rRNA) gene and the highly polymorphic 60 kDa glycoprotein (gp60) gene followed by sequence analyses. The results of this study revealed that 25.6% (106 of 415) of the specimens were positive for Cryptosporidium spp. infection. We identified 27.4% (91/333), 19.4% (13/67), and 13.4% (2/15) of positivity in calves, lambs and goat kids, respectively. Genotyping of the SSU rRNA indicated that almost all positive specimens were of C. parvum, except for one calf which was of C. bovis. Sequence analysis of the gp60 gene revealed the most common zoonotic subtypes (IIa and IId) of C. parvum. We detected 11 subtypes (IIaA11G2R1, IIaA11G3R1, IIaA12G3R1, IIaA13G2R1, IIaA13G4R1, IIaA14G1R1, IIaA14G3R1, IIaA15G2R1, IIdA16G1, IIdA18G1, IIdA22G1); three of them (IIaA12G3R1, IIaA11G3R1 and IIaA13G4R1) was novel subtypes found in calves and lambs. Additionally, three subtypes (IIaA11G2R1, IIaA14G3R1, and IIdA16G1) were detected in young ruminants for the first time in Turkey. These results indicate the high infection of Cryptosporidium in Turkey and propose that young ruminants are likely a major reservoir of C. parvum and a potential source of zoonotic transmission.  相似文献   

8.
Cryptosporidium spp. represent a major public health problem worldwide and infect the gastrointestinal tract of both immunocompetent and immunocompromised persons. The prevalence of these parasites varies by geographic region, and no data are currently available in Lebanon. To promote an understanding of the epidemiology of cryptosporidiosisin this country, the main aim of this study was to determine the prevalence Cryptosporidium in symptomatic hospitalized patients, and to analyze the genetic diversity of the corresponding isolates. Fecal specimens were collected in four hospitals in North Lebanon from 163 patients (77 males and 86 females, ranging in age from 1 to 88 years, with a mean age of 22 years) presenting gastrointestinal disorders during the period July to December 2013. The overall prevalence of Cryptosporidium spp. infection obtained by modified Ziehl-Neelsen staining and/or nested PCR was 11%, and children <5 years old showed a higher rate of Cryptosporidium spp. The PCR products of the 15 positive samples were successfully sequenced. Among them, 10 isolates (66.7%) were identified as C. hominis, while the remaining 5 (33.3%) were identified as C. parvum. After analysis of the gp60 locus, C. hominis IdA19, a rare subtype, was found to be predominant. Two C. parvum subtypes were found: IIaA15G1R1 and IIaA15G2R1. The molecular characterization of Cryptosporidium isolates is an important step in improving our understanding of the epidemiology and transmission of the infection.  相似文献   

9.
Little is known of the occurrence and age patterns of species/genotypes and subtypes of Cryptosporidium spp. and Giardia duodenalis in calves in Egypt. In this study, 248 fecal specimens were collected from dairy calves aged 1?day to 6?months on eight farms in three provinces during March 2015 to April 2016. Cryptosporidium spp. were detected and genotyped by using PCR-RFLP analysis of the small subunit rRNA (SSU rRNA) gene, while G. duodenalis was detected and genotyped by using PCR and sequence analyses of the triose phosphate isomerase (tpi), glutamate dehydrogenase (gdh) and β-giardin (bg) genes. The overall infection rates of Cryptosporidium spp. and G. duodenalis were 9.7 and 13.3%, respectively. The highest Cryptosporidium infection rate (26.7%) was in calves of age?≤?1?month while the highest G. duodenalis infection rate (44.4%) was in calves of 2?months. Three Cryptosporidium spp. were identified, including C. parvum (n?=?16), C. bovis (n?=?5) and C. ryanae (n?=?3), with the former being almost exclusively found in calves of ≤3?months of age and the latter two being only found in calves of over 3?months. Subtyping of C. parvum by PCR-sequence analysis of the 60?kDa glycoprotein gene identified subtypes IIaA15G1R1 (n?=?15) and IIaA15G2R1 (n?=?1). The G. duodenalis identified included both assemblages E (n?=?32) and A (n?=?1), with the latter belonging to the anthroponotic subtype A2. These data provide new insights into the genetic diversity and age patterns of Cryptosporidium spp. and G. duodenalis in calves in Egypt.  相似文献   

10.
The subtype IIaA15G2R1 at the 60 kDa glycoprotein (gp60) gene locus is the most dominant Cryptosporidium parvum infecting dairy cattle and humans in industrialised nations. The reasons for its high transmissibility are not clear, and it remains to be determined whether this subtype represents a homogeneous parasite population. In this study, we sequence-characterised 26 IIaA15G2R subtype specimens and 26 non-IIaA15G2R subtype specimens from the United States, Canada, United Kingdom and Spain at seven other known polymorphic loci, including CP47, CP56, DZ-HRGP, MSC6-5, MSC6-7, RPGR and ZPT. Extensive heterogeneity within IIaA15G2R1 and discordance in typing results between gp60 and other genetic markers were observed. Results of inter-locus and intra-ZPT linkage disequilibrium and recombination analyses indicated that the heterogeneity within IIaA15G2R1 and discordance in typing results among genetic loci were largely due to the occurrence of genetic recombination, mostly within the gp60 subtype IIaA15G2R1. Although there was no clear population diversion between IIaA15G2R and non-IIaA15G2R subtypes, results of STRUCTURE and FST analyses suggested the presence of at least two subpopulations; subpopulation 1 had an epidemic population structure and was widely distributed, whereas subpopulation 2 had a clonal population structure and consisted of geographically segregated multilocus subtypes. Genetic recombination between epidemic and geographically segregated C. parvum populations appeared to be a driving force in the emergence of a hyper-transmissible IIaA15G2R1 subtype. Genetic recombination was observed even between the zoonotic IIa subtype family and anthroponotic subtype family IIc at CP56, MSC6-7 and ZPT. Thus, the IIaA15G2R1 subtype at gp60 is likely a fitness marker for C. parvum and the wide spread of IIaA15G2R1 subtype around the world is probably independent of the sequence characteristics at other genetic loci.  相似文献   

11.

Background

Cryptosporidiosis is an important cause for chronic diarrhea and death in HIV/AIDS patients. Among common Cryptosporidium species in humans, C. parvum is responsible for most zoonotic infections in industrialized nations. Nevertheless, the clinical significance of C. parvum and role of zoonotic transmission in cryptosporidiosis epidemiology in developing countries remain unclear.

Methodology/Principal Findings

In this cross-sectional study, 520 HIV/AIDS patients were examined for Cryptosporidium presence in stool samples using genotyping and subtyping techniques. Altogether, 140 (26.9%) patients were positive for Cryptosporidium spp. by PCR-RFLP analysis of the small subunit rRNA gene, belonging to C. parvum (92 patients), C. hominis (25 patients), C. viatorum (10 patients), C. felis (5 patients), C. meleagridis (3 patients), C. canis (2 patients), C. xiaoi (2 patients), and mixture of C. parvum and C. hominis (1 patient). Sequence analyses of the 60 kDa glycoprotein gene revealed a high genetic diversity within the 82 C. parvum and 19 C. hominis specimens subtyped, including C. parvum zoonotic subtype families IIa (71) and IId (5) and anthroponotic subtype families IIc (2), IIb (1), IIe (1) and If-like (2), and C. hominis subtype families Id (13), Ie (5), and Ib (1). Overall, Cryptosporidium infection was associated with the occurrence of diarrhea and vomiting. Diarrhea was attributable mostly to C. parvum subtype family IIa and C. hominis, whereas vomiting was largely attributable to C. hominis and rare Cryptosporidium species. Calf contact was identified as a significant risk factor for infection with Cryptosporidium spp., especially C. parvum subtype family IIa.

Conclusions/Significance

Results of the study indicate that C. parvum is a major cause of cryptosporidiosis in HIV-positive patients and zoonotic transmission is important in cryptosporidiosis epidemiology in Ethiopia. In addition, they confirm that different Cryptosporidium species and subtypes are linked to different clinical manifestations.  相似文献   

12.

Background

Cryptosporidium hominis is a dominant species for human cryptosporidiosis. Within the species, IbA10G2 is the most virulent subtype responsible for all C. hominis–associated outbreaks in Europe and Australia, and is a dominant outbreak subtype in the United States. In recent yearsIaA28R4 is becoming a major new subtype in the United States. In this study, we sequenced the genomes of two field specimens from each of the two subtypes and conducted a comparative genomic analysis of the obtained sequences with those from the only fully sequenced Cryptosporidium parvum genome.

Results

Altogether, 8.59-9.05 Mb of Cryptosporidium sequences in 45–767 assembled contigs were obtained from the four specimens, representing 94.36-99.47% coverage of the expected genome. These genomes had complete synteny in gene organization and 96.86-97.0% and 99.72-99.83% nucleotide sequence similarities to the published genomes of C. parvum and C. hominis, respectively. Several major insertions and deletions were seen between C. hominis and C. parvum genomes, involving mostly members of multicopy gene families near telomeres. The four C. hominis genomes were highly similar to each other and divergent from the reference IaA25R3 genome in some highly polymorphic regions. Major sequence differences among the four specimens sequenced in this study were in the 5′ and 3′ ends of chromosome 6 and the gp60 region, largely the result of genetic recombination.

Conclusions

The sequence similarity among specimens of the two dominant outbreak subtypes and genetic recombination in chromosome 6, especially around the putative virulence determinant gp60 region, suggest that genetic recombination plays a potential role in the emergence of hyper-transmissible C. hominis subtypes. The high sequence conservation between C. parvum and C. hominis genomes and significant differences in copy numbers of MEDLE family secreted proteins and insulinase-like proteases indicate that telomeric gene duplications could potentially contribute to host expansion in C. parvum.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1517-1) contains supplementary material, which is available to authorized users.  相似文献   

13.
Cryptosporidium is a gastrointestinal parasite that is recognised as a significant cause of non-viral diarrhea in both developing and industrialised countries. In the present study, a longitudinal analysis of 248 faecal specimens from Australian humans with gastrointestinal symptoms from 2005 to 2008 was conducted. Sequence analysis of the 18S rRNA gene locus and the 60 kDa glycoprotein (gp60) gene locus revealed that 195 (78.6%) of the cases were due to infection with Cryptosporidium hominis, 49 (19.8%) with Cryptosporidium parvum and four (1.6%) with Cryptosporidium meleagridis. A total of eight gp60 subtype families were identified; five C. hominis subtype families (Ib, Id, Ie, If and Ig), and two C. parvum subtype families (IIa and IId). The Id subtype family was the most common C. hominis subtype family identified in 45.7% of isolates, followed by the Ig subtype family (30.3%) and the Ib subtype family (20%). The most common C. parvum subtype was IIaA18G3R1, identified in 65.3% of isolates. The more rare zoonotic IId A15G1 subtype was identified in one isolate. Statistical analysis showed that the Id subtype was associated with abdominal pain (p < 0.05) and that in sporadic cryptosporidiosis, children aged 5 and below were 1.91 times and 1.88 times more likely to be infected with subtype Id (RR 1.91; 95% CI, 1.7-2.89; p < 0.05) and Ig (RR 1.88; 95% CI, 1.10-3.24; p < 0.05) compared to children aged 5 and above. A subset of isolates were also analysed at the variable CP47 and MSC6-7 gene loci. Findings from this study suggest that anthroponotic transmission of Cryptosporidium plays a major role in the epidemiology of cryptosporidiosis in Western Australian humans.  相似文献   

14.
The genetic diversity of Cryptosporidium spp. in Apodemus spp. (striped field mouse, yellow-necked mouse and wood mouse) from 16 European countries was examined by PCR/sequencing of isolates from 437 animals. Overall, 13.7% (60/437) of animals were positive for Cryptosporidium by PCR. Phylogenetic analysis of small-subunit rRNA, Cryptosporidium oocyst wall protein and actin gene sequences showed the presence of Cryptosporidium ditrichi (22/60), Cryptosporidium apodemi (13/60), Cryptosporidium apodemus genotype I (8/60), Cryptosporidium apodemus genotype II (9/60), Cryptosporidium parvum (2/60), Cryptosporidium microti (2/60), Cryptosporidium muris (2/60) and Cryptosporidium tyzzeri (2/60). At the gp60 locus, novel gp60 families XVIIa and XVIIIa were identified in Cryptosporidium apodemus genotype I and II, respectively, subtype IIaA16G1R1b was identified in C. parvum, and subtypes IXaA8 and IXcA6 in C. tyzzeri. Only animals infected with C. ditrichi, C. apodemi, and Cryptosporidium apodemus genotypes shed oocysts that were detectable by microscopy, with the infection intensity ranging from 2000 to 52,000 oocysts per gram of faeces. None of the faecal samples was diarrheic in the time of the sampling.  相似文献   

15.
Little is known about the epidemiology of Cryptosporidium in Jordan and no genotyping studies have been conducted on Cryptosporidium isolates from humans or animals from Jordan. Genotyping of 44 Cryptosporidium isolates from Jordanian children at the 18S rRNA locus and a unique diagnostic locus identified four Cryptosporidium species; C. parvum (22), C. hominis (20), C. meleagridis (1) and C. canis (1). Sub-genotype analysis of 29 isolates at the 60-kDa glycoprotein (GP60) locus identified three C. parvum, two C. hominis subtype families and one C. meleagridis subtype. Several rare and novel subtypes were identified indicating unique endemicity and transmission of Cryptosporidium in Jordan.  相似文献   

16.
Soba B  Logar J 《Parasitology》2008,135(11):1263-1270
To assess the importance of cattle as a source of human cryptosporidial infections in Slovenia, Cryptosporidium isolates from calves and humans with cryptosporidiosis were characterized genetically by direct DNA sequencing, targeting a variable region of the 60 subtypes', were identified, of which 7 were novel. In humans, C. hominis Ia (subtype IaA17R3) and Ib (IbA10G2) and Cryptosporidium parvum IIa (IIaA9G1R1, IIaA11G2R1, IIaA13R1, IIaA14G1R1, IIaA15G1R1, IIaA15G2R1, IIaA16G1R1, IIaA17G1R1 and IIaA19G1R1), IIc (IIcA5G3), and IIl (IIlA16R2) were recorded; this is the first record of the latter subtype in humans. In cattle, C. parvum IIa (IIaA13R1, IIaA15G2R1, IIaA16R1 and IIaA16G1R1) and IIl (IIlA16R2 and IIlA18R2) were recorded. Of the 15 subtypes identified, subtypes of C. parvum IIa were the most frequently encountered (>90%) in both humans and calves. The present findings suggest that zoonotic transmission plays an important role in sporadic human cryptosporidiosis in Slovenia.  相似文献   

17.

Background

Cryptosporidium infection is a worldwide cause of diarrheal disease. To gain insight into the epidemiology of the infection in a certain geographic area, molecular methods are needed to determine the species/genotypes and subtypes.

Methodology/Principal Findings

From 2004 to 2009, 161 cryptosporidiosis cases were detected in two hospitals in Barcelona. Diagnosis was performed by microscopic observation of oocysts in stool specimens following modified Ziehl-Neelsen staining. Most cases (82%) occurred in children. The number of cases increased in summer and autumn. Molecular characterization of Cryptosporidium was performed in 69 specimens, and C. hominis and C. parvum were identified in 88.4% and 10.1% of the cases, respectively. C. meleagridis was detected in one specimen. Subtyping based on the gp60 polymorphism showed six subtypes, four C. hominis and two C. parvum. Subtype IbA10G2 was the most prevalent subtype corresponding to 90% of all C. hominis isolates. This is the first report on the distribution of specific Cryptosporidium subtypes from humans in Spain.

Conclusions/Significance

In our geographic area, the anthroponotic behavior of C. hominis, the lower infective dose, and the higher virulence of certain subtypes may contribute to the high incidence of human cryptosporidiosis caused by the IbA10G2 subtype. Further studies should include populations with asymptomatic shedding of the parasite.  相似文献   

18.
Rare systemic studies concerning prevalence of intestinal parasites in children have been conducted in the second smallest country in Africa, the Democratic Republic of São Tomé and Príncipe. Fecal specimens from 348 children (214 in-hospital attending the Aires de Menezes Hospital and 134 from Agostinho Neto village) in São Tome Island were studied by parasitological and molecular methods. Of the 134 children from Agostinho Neto, 52.2% presented intestinal parasites. 32.1% and 20.2% of these children had monoparasitism and polyparasitism, respectively. Ascaris lumbricoides (27.6%), G. duodenalis (7.5%), T. trichiura (4.5%) and Entamoeba coli (10.5%) were the more frequent species identified in the children of this village. Giardia duodenalis (7.5%) and E. bieneusi (5.2%) were identified by PCR. Nested-PCR targeting G. duodenalis TPI identified Assemblage A (60%) and Assemblage B (40%). The E. bieneusi ITS-based sequence identified genotypes K (57.1%), KIN1 (28.6%) and KIN3 (14.3%). Among the 214 in-hospital children, 29.4% presented intestinal parasites. In 22.4% and 7.0% of the parasitized children, respectively, one or more species were concurrently detected. By microscopy, A. lumbricoides (10.3%) and Trichiuris trichiura (6.5%) were the most prevalent species among these children, and Cryptosporidium was detected by PCR in 8.9% of children. GP60 locus analysis identified 6.5% of C. hominis (subtypes IaA27R3 [35.7%], IaA23R3 [14.3%], IeA11G3T3 [28.6%] and IeA11G3T3R1 [21.4%]) and 2.3% of C. parvum (subtypes IIaA16G2R1 [20.0%], IIaA15G2R1 [20.0%], IIdA26G1 [40.0%] and IIdA21G1a [20.0%]). G. duodenalis and E. bieneusi were identified in 0.5% and 8.9% of the in-hospital children, respectively. G. duodenalis Assemblage B was characterized. The E. bieneusi genotypes K (52.6%), D (26.4%), A (10.5%) and KIN1 (10.5%) were identified. Although further studies are required to clarify the epidemiology of these infectious diseases in this endemic region the significance of the present results highlights that it is crucial to strength surveillance on intestinal pathogens.  相似文献   

19.
Molecular typing at the 18S rRNA and Gp60 loci was conducted on Cryptosporidium-positive stool samples from cases collected during 2007 Western Australian and South Australian outbreaks of cryptosporidiosis. Analysis of 48 Western Australian samples identified that all isolates were C. hominis and were from five different Gp60C. hominis subtype families. The IbA10G2 subtype was most common across all age groups (37/48). In South Australia, analysis of 24 outbreak samples, identified 21 C. hominis isolates, two C. parvum isolates and one sample with both C. hominis and C. parvum. All C. hominis isolates were identified as the IbA10G2 subtype.  相似文献   

20.
This research had as objective to evaluate the occurrence and to characterize genetically the infections by Cryptosporidium in Mazama gouazoubira. By a non-invasive harvest methodology using trained sniffer dogs to locate fecal samples of cervids, 642 fecal samples were obtained from six Brazilian localities. The cervids species responsible for the excretion of each fecal sample were identified by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), using the mitochondrial cytochrome b target gene (cyst b) and the restriction enzymes Sspl, AflIII and BstN. From this identification, 437 fecal samples of M. gouazoubira were selected for research of Cryptosporidium spp. performed through negative staining with malachite green and polymerase chain reaction (nPCR), with the subunit of 18S rRNA gene, followed by sequencing the amplified products. In the samples that were diagnosed the presence of parasite species with zoonotic potential, genotyping was also performed using nPCR with the subunit of GP60 gene. Statistical analysis consisted of the Fisher exact test to verify the association of the presence of the enteroparasite in relation to the presence of cattle in each locality, and the McNemar tests and Kappa correlation coefficient used to compare the results obtained between the two diagnostic techniques. In the fecal samples of M. gouazoubira the occurrences of Cryptosporidium were diagnosed in 1.6% (7/437) and 1.1% (5/437), respectively, through nPCR and microscopy. Cryptosporidium. parvum was diagnosed in 100% (7/7) of the samples submitted to sequencing (18S gene). The IIaA16G3R1 subtype was diagnosed in five of the C. parvum samples submitted to genotyping (GP60 gene). This is the first world report of C. parvum in M. gouazoubira and subtype IIaA16G3R1 in cervids.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号