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 15 毫秒
1.

Background

Cryptosporidium parvum is a zoonotic pathogen transmissible from a variety of animals to humans and is a considerable public health concern. Dairy cattle have been identified in numerous reports as a major source of environmental contamination with this pathogen. The aim of study was to detect and isolate the Cryptosporidium spp. from fecal samples of naturally infected pre-wean calves in the Mashhad area

Methods

Overall, 300 fecal specimens from 1 to 30 days pre-weaned calves were collected from 10 farms in the Mashhad area the capital center of the Khorasan Razavi Province, Iran and microscopically examined for Cryptosporidium spp. All infected samples were also analyzed using nested –PCR. A polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis of the small-subunit (SSU) rRNA gene was also used to detect and identify Cryptosporidium spp. in PCR- positive samples.

Results

Eighty five (28.3%) of the specimens were positive for Cryptosporidium spp. The prevalence of Cryptosporidium spp. in 8-14 days old and diarrheic calves were significantly higher than other groups. Restriction digestion of the PCR products by SspI, VspI restriction enzymes and sequence analysis revealed the presence of C. parvum bovine genotype in all isolates.

Conclusions

Our results suggest that pre-weaned calves are likely to be an important reservoir of zoonotic C. parvum.  相似文献   

2.

Background

Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determination of subtypes of Cryptosporidium among children with diarrhea in Tehran by sequence analysis of the highly polymorphic 60-kDa glycoprotein (GP60) gene.

Methods

Fecal samples were collected from 794 diarrheic children. Initial identification of Cryptosporidium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly.

Results

Out of 794 collected samples, 19 (2.40%) were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 (89.47%) of the positive isolates were Cryptosporidium parvum and 2 (10.52%) were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa (6/17) and IId (11/17). The most common allele in all 17 isolates belonged to IId A20G1a (41.18%). A22G1 (IF) subtype was detected in two C. hominis isolates of the children.

Conclusion

The predominancy of C. parvum species (specially, IId A20G1a subtype) in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran.  相似文献   

3.

Background

Cryptosporidium spp. is a coccidian parasite infected humans and animals. Prevalence rate of Cryptosporidium spp. infection associated with is some parameters such as sampling, age, season, country and contact to domestic animals. This study aimed to determine Cryptosporidium spp. Infection in humans and some animals in rural areas of Shushtar district from Khuzestan Province, south- west of Iran.

Methods

In this study, Stool specimens were randomly collected from 45 cattle, 8 buffalos, 35 calves, 22 turkeys, 3 sheep, 2 geese as well as 62 humans in different seasons selected from rural areas of Shushtar district located in Khuzestan in the south- west of Iran from August 2009 to April 2011. The collected stool samples were examined by modified Ziehl-Neelsen staining method.

Results

Altogether, 68/115 (59.1%) domestic animals and 9/62 (14.5%) of humans were showed Cryptosporidium spp. infection in the study areas.

Conclusion

In this study we found the high frequency of Cryptosporidium spp. infection in the studied areas.  相似文献   

4.

Background

Cryptosporidiosis is one of the most important parasitic infections in human and animals. This study was designed for survey on the prevalence of Cryptosporidium infection in farms of Ilam, west of Iran, using parasitology method and genotyping by Nested PCR-RFLP.

Methods

Fecal samples of 217 cattle were collected fresh and directly from the rectum of cattle. All of the samples were examined by microscopic observation after staining with modified Ziehl-Neelsen (MZN). Genomic DNA extracted by using EURx DNA kit. A Nested PCR-RFLP protocol amplifying 825 bp fragment of 18s rRNA gene conducted to differentiate species and genotyping of the isolates using SspI and VspI as restriction enzymes.

Results

The prevalence of Cryptosporidium infection in cattle using both methods is 3.68%. Most of the positive cattle were calves under six months. Species diagnosis carried out by digesting the secondary PCR product with SspI that C. parvum generated 3 visible bands of 448, 247 and 106 bp and digested by VspI restriction enzyme generated 2 visible bands of 628 and 104bp. In this investigation all of the positive samples were Cryptosporidium parvum.

Conclusion

C. parvum (bovine genotype) detected in all positive cattle samples in Ilam, west of Iran. The results of the present study can help for public health care systems to prevention and management of cryptosporidiosis in cattle and the assessment of cattle cryptosporidiosis as a reservoir for the human infection.  相似文献   

5.

Background

The main goal of the present study was to develop a new sensitive and specific PCR based method for Identification of Cryptosporidium sp. using novel primers from 18S ribosomal RNA. Cryptosporidiosis in high-risk host groups particularly in neonates and immuno-compromised individuals may result in death. To the best of our knowledge this is the first study regarding develop a new PCR based method to diagnose the cryptosporidiosis in Iran.

Methods

A total of 850 human fecal samples from patients clinically suspected to cryptosporidiosis and 100 healthy and diarrheic cattle stool specimens were collected. The simplified formol-ether concentration method was carried out for all samples. They were then examined microscopically by modified Ziehl-Neelsen staining method. Total DNA was extracted by QIA amp DNA stool mini kit. PCR and nested-PCR was carried out by using designed primers.

Results

Twenty nine cases of cryptosporidiosis infection in human and 30 samples from cattle microscopically were positive. The described primary and nested PCR method could detect all Cryptosporidium positive samples from human and cattle. Regards to suspected negative samples in primary PCR examination, the Nested PCR could approve two more positive results. Furthermore, Nested PCR analysis was able to detect one more case which was negative in both microscopically examination and primary PCR. Specificity of the test was 100%. Sensitivity of Nested PCR in comparison to our gold standard; microscopy after Ridley concentration modified ziehl-Neelsen, was 100%.

Conclusion

Our developed PCR based method by using new primers devised from 18S ribosomal RNA revealed the ability for identification of the Cryptosporidium species such as C. parvum and C. huminis with high specificity and sensitivity.  相似文献   

6.

Background

The protozoan parasites Cryptosporidium spp. and Giardia are known to occur widely in both raw and drinking waters. They are two of the causative agents of waterborne outbreaks of gastroenteritis throughout the world. In the present study, a PCR assay and FA were developed for detection of Cryptosporidium oocysts and Giardia cyst in environmental samples.

Methods

We have detected Cryptosporidium spp. oocysts and Giardia cysts in seeded and unseeded environmental water samples by PCR method. Water samples were spiked with oocysts (50, 100,300,500) and filtrated with a 1.2-µm pore size cellulose nitrate and follow by DNA extraction and purification by QIAamp DNA mini kit. Nested-PCR assay amplified an 850 bp fragment of 18s rRNA gene specific for Cryptosporidium and 435 bp fragment of glutamate dehydrogenase (GDH) target gene for Giardia. Also many river water from north of Iran, be checked by these methods.

Results

Cryptosporidium and Giardia DNAs were detected in seeded water sample and Giardia was detected in all 5 water samples from river in north of Iran by nested- PCR and FA. Also in one river water sample, Cryptosporidium was detected.

Conclusion

This protocol is effective for detection of these waterborne parasites in treated and untreated water samples. This study can also serve as a platform for further investigations and research water source in Iran.  相似文献   

7.

Background

Cryptosporidium species are important cause of diarrheal diseases in both developing and developed countries. This study aimed to compare the performance of several molecular methods for identification of Cryptosporidium species, and to detect genetic variation among each of these species isolated from Iran, Malawi, Nigeria, Vietnam and the United Kingdom.

Methods

The oocysts DNA samples were derived from 106 Cryptosporidium positive feces. Polymerase chain reaction, PCR- restriction fragment length polymorphism and DNA sequence analysis of the 18S rRNA and the Cryptosporidium oocysts wall protein genes; PCR and DNA sequence analysis of a fragment of 70 kDa heat shock protein and 60 kDa glycoprotein genes were carried out.

Results

Based on these analysis, three species of Cryptosporidium including C. hominis, C. parvum and C. meleagridis, and both C. hominis and C. parvum were found in Iranian and the UK samples, respectively. Also, three C. hominis (Ib, Ib3& Id) and three C. parvum (IIa, IIc & IId) subtypes were identified by sequence analysis of the GP60 gene. Of these, C. hominis Ib was predominant and interestingly, one subgenotype (C. hominis Ib A10G2) accounted for the majority of the samples.

Conclusion

The current study demonstrates the complex subtypes of Cryptosporidium isolates in both developing and developed countries. This is the first report of C. parvum IId subgenotype and three new subtypes of C. parvum IIa in the UK, a new subtype of C. hominis Id from Malawi; and the first multi-locus study of three species of Cryptosporidium in human from Iran.  相似文献   

8.

Background

Although infection of dromedary camels with Cryptosporidium spp. is rare in Iran, it is considered a zoonotic threat to the keepers and herders of camels. Thus we investigated the prevalence of Cryptosporidium in these two hosts in Yazd Province, a semi-arid region in center of Iran.

Methods

This study was conducted during 4 seasons (winter 2008, summer 2009, winter 2009 and summer 2010). Fecal samples (n=200) were collected from live camels. Also, 100 abomasal mucosa and related fecal samples of the slaughtered camels were investigated. Stool samples from 100 individuals who were in persistent contact with camels were also obtained. After staining by modified Ziehl-Neelsen method, the prepared specimens were studied microscopically. Results were analyzed using SPSS 16.

Results

The rate of infection in feces and abomasal mucosa of camels were 20.33% and 12%, respectively. In addition, simultaneous fecal and mucosal infection was detected in 3 cases in winter. Statistical analyses showed no significant relation between infection and age of camels, as well as their sex and the season. Cryptosporidiosis in people who were in long-term contact with camels was also investigated microscopically by obtaining stool samples of 100 individuals (50 in summers, 50 in winters), 24 of them being infected with Cryptosporidium spp. The rate of infection was higher in winter than summer (16/50 compared with 8/50).

Conclusion

The prevalence of Cryptosporidium spp. in camels and involved humans in Yazd Province is relatively considerable and of public health importance.  相似文献   

9.

Background

This is the first work done on cryptosporidiosis among the children in Taiz, Yemen.

Methods

A number of 712 samples were collected from children of different ages (ranging from 1 month to 12 years) from Dec 2006 to Aug 2007. The collected samples were examined by Sheather''s sugar floatation and Modified Ziehl- Neelsen stain as well as ELISA methods. The test results were statistically analyzed by SPSS software.

Results

The overall positive percentage was 43.7%. The higher incidence (36.2%) was occurred in males while the lowest incidence (32.7%) was observed in females (r=0.876; P=0.001). The correlation between infected cases and the type of drinking water was r =0.121. Among the cases examined by ELISA (92 cases), 26.1% were infected. The correlation between seropositivity and gender was r=0.652 (P=0.031).

Conclusion

Cryptosporidium spp. is a significant pathogen among children at Taiz. Fresh water supplies, education, eating habits and domestic animals are considered the main sources for transmission of cryptosporidiosis.  相似文献   

10.

Background

Cryptosporidiosis is a common coccidian parasite infection in patients with diarrhea that has worldwide distribution especially in developed countries. Therefore, the aim of this study was to determine the occurrence of Cryptosporidium infection in patients with gastroenteritis admitted to hospitals of Mazandaran University of Medical Sciences by parasitological and molecular methods in Sari, Iran.

Methods

Stool samples were collected from 348 patients with gastroenteritis admitted to the hospitals of Medical University in the Sari and Ghaemshahr cities in Mazandaran Province, Northern Iran in 2010-2011. Oocysts of Cryptosporidium identified using Formalin-Ether concentration method and stained by Aacid-fast staining (AFS) and Auramine phenol fluorescence (APF). Genomic DAN extracted from microscopically positive samples and nested PCR -RFLP by using SSU rRNA that identifies of the species of cryptosporidium.

Results

In 348 patients with gastroenteritis, the most clinical symptoms were diarrhea, nausea, vomiting, dehydration, fever and weight loss. 2.3% (8 cases) of diarrheal samples tested by both microscopy and molecular methods were positive for the presence of cryptosporidium. Nested PCR products yielded unique bands of 846 bp, correspond to cryptosporidium. Species diagnosis carried out by digesting the secondary PCR product with SspI restriction enzyme, which noted 3 clearly bands of 449, 254, and 108 bp correspond to Cryptosporidium spp.

Conclusion

The results of present study on Cryptosporidium spp. in this area can make a background data for control programs and further molecular analyses. Thus, further work needs to determine the origin of Cryptosporidium species in this area.  相似文献   

11.
12.

Background

The objective of the present research was to determine the frequency of Toxocara spp. eggs in soil samples of public parks, in the city of Tehran, Iran.

Methods

A total of 600 soil samples were taken from 120 parks between Aprils to November, 2008. Soil samples were collected from 5 distinct sites in the parks. The samples were washed with saline solution and the collected sediment from each park were equally divided and examined by floatation and Petri dish methods for Toxocara eggs.

Results

Ten percent were contaminated with Toxocara spp. eggs. The number of observed Toxocara eggs in each microscopic field was varied from 1-3. No significant differences were observed between floatation and Petri dish methods.

Conclusion

Our public parks showed a high risk of toxocariasis and the need for preventive studies.  相似文献   

13.

Background:

Naegleria spp. is a free-living amoeba of which some species including N. fowleri and N. australeinsis are highly pathogenic in human and animals. These widespread amoebae could be found in different environmental sources particularly in aquatic resources of tropical and subtropical regions. The most important source of infection is via recreational water contact. Due to the lack of thorough research regarding species of Naegleria spp. in aquatic sources, the present study was conducted.

Methods:

In the present study, 60 samples were collected from recreational water resources of Rasht city, Guilan province, north of Iran. After filtering and culturing the samples, plates were examined by microscopic method and according to the page criteria. DNA of vahlkampfiid-positive samples were then extracted using phenol-chlorophorm method. Amoebae genus was identified by targeting the ITS-region and sequencing based-approaches.

Results:

Nine (15%) samples out of a 60 total samples were positive for Naegleria spp. of which seven belonged to potentially pathogenic N. australiensis. Two other strains were belonged to non-pathogenic N. pagei.

Conclusion:

The present research was the first report of occurrence of N. australiensis and N. pagei in Rasht city, north Iran. This study reflects the occurrence of Naegleria spp. in water sources of Guilan Province, Iran.  相似文献   

14.

Background

Cryptosporidium parvum causes severe gastroenteritis in immunocompromised human and new borne animals. The organism can be transmitted through water. Since small number of C. parvum is infectious, the aim of the present study was to develop a chromatography method for the isolation of C. parvum oocyst in samples with limited number of oocysts.

Methods

Antibody was prepared against whole antigen from C. parvum oocysts, the achieved Ab bound to the sepharose 4B and used for the isolation of oocysts. Antibody against P23 bound to the sepharose 4B, used also for the isolation of C. parvum oocyst. In comparison to these both methods, 2 traditional methods (Salt floatation and 55% sucrose floatation) were also performed.

Results

Both chromatography methods could bind oocysts with capacity depends on the column size. The isolated oocysts were free of bacteria. Our results showed that the traditional methods are useful for the isolation of oocysts from feces, in its smear stained with ziehl-nelsen, at least 3 oocyts are detectable in each microscopic field under 1000 X magnification. In contrast to the chromatography methods, the bacterial contamination was always observed in oocysts isolated with traditional methods.

Conclusion

Immunochromatography could be used for the successful isolation of C. parvum oocysts from the samples containing limited number of oocysts.  相似文献   

15.

Background

The aim of this study was to determine the seroprevalence of antibody to Neospora caninum in healthy and aborted dairy cattle in Tabriz, capital of East-Azarbaijan in northwest of Iran.

Methods

In this cross-sectional study serum samples were collected from 266 healthy and aborted Holestein-Feriesisnc cows from September 2008 to August 2009. The sera were analyzed to detect of antibody against N. caninum using the commercially ELISA kit.

Results

Seroprevalence of antibody to N. caninum was 10.5% in Tabriz dairy cattle. Also the abortion rate in all cattle sampled was 33.6% but percentage of seropositive aborted cattle was 18.4%.

Conclusion

Neosporosis could be one of the possible causes of abortion in dairy cattle in Tabriz and regarding the distribution in dogs as definitive host for the parasite, further studies in dog and cattle are recommended.  相似文献   

16.

Background

Acanthamoeba spp. are free-living amoebae commonly found in the environmental sources such as water, soil, and air. This ubiquitous amoeba is the causative agent of amoebic keratitis (AK). The objective of the present study was to investigate the presence of Acanthamoeba spp. in water and soil sources in Ahvaz City, Khuzestan Province, southern Iran.

Methods

In general, 110 samples of water and soil were taken from different localities of Ahvaz including agricultural canals, rivers, and swimming pools. Filtration and cultivation were carried out on non-nutrient agar medium (NNA). Axenic cultivation was performed for all of positive isolates. PCR analysis was conducted on positive samples. Sequencing was done for 15 PCR products. Genotypes were identified by Blast search and homology analysis.

Results

Acanthamoeba spp. was found in 43 (71.6%) of samples of water and 13 (26%) soil samples. Genotyping of 15 samples proved that Acanthamoeba belonged to T4 (86.6%), T2 (6.6%), and T5 (6.6%) genotypes.

Conclusion

TYI-S-33 medium could be better than PYG medium for Acanthamoeba axenic culture.  相似文献   

17.

Background

Free-living amoebae (FLA) are a group of ubiquitous protozoan, which are distributed in the natural and artificial environment sources. The main aim of the current study was to identify the presence of FLA in the recreational hot springs of Sarein in Ardebil Province of Iran.

Methods

Seven recreational hot springs were selected in Sarein City and 28 water samples (four from each hot spring) were collected using 500 ml sterile plastic bottles during three month. Filtration of water samples was performed, and culture was done in non-nutrient agar medium enriched with Escherichia coli. Identification of the FLA was based on morphological criteria of cysts and trophozoites. Genotype identification of Acanthamoeba positive samples were also performed using sequencing based method.

Results

Overall, 12 out of 28 (42.9%) samples were positive for FLA which Acanthamoeba and Vahlkampfiid amoebae were found in one (3.6%) and 11 (39.3%) samples, respectively. Sequence analysis of the single isolate of Acanthamoeba revealed potentially pathogenic T4 genotype corresponding to A. castellanii.

Conclusion

Contamination of hot springs to FLA, such as Acanthamoeba T4 genotype (A. castellanii) and Vahlkampfiid amoebae, could present a sanitary risk for high risk people, and health authorities must be aware of FLA presence.  相似文献   

18.

Background

Geothermal waters could be suitable niches for thermophilic free living amoebae including Naegleria and Hartmannella. Ardebil Province, northwest Iran is popular for having many hot springs for recreational and health purposes activity. The present research is the first molecular based investigation regarding the presence of Naegleria and Hartmannella in the hot springs of Ardebil Province in Iran.

Methods

Overall, 30 water samples were taken from waters of thermal hot springs in Ardebil Province, Iran during 2010-2011. All collected samples were transferred to Dept. of Parasitology and Mycology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Cultivation of concentrated water samples was performed using culture-enrichment method. Cloning of the target amoebae was obtained and morphological and molecular analysis was done using page key combined with two sets of primers, respectively. Sequence analysis and homology search was used for strains identification.

Results

Of 30 water samples, 8 (26.7%) were positive for thermotolerant Vahlkampfiids and Hartmannella based on morphological characteristics of vegetative form and double walled cysts. Cloning of the target amoebae were done successfully. Sequencing of the positive isolates revealed that the strains belonged to Naegleria (N. carteri and N. spp) and H. vermiformis.

Conclusion

The result highlights a need for improved filtration and disinfection and periodic monitoring of recreational thermal waters in order to prevent disease related to free- living amoebae. This is the first comprehensive molecular study of thermophilic Naegleria and Hartmannella in hot springs of Iran.  相似文献   

19.

Background

We attempted to determine the prevalence of Hepatozoon spp. infection in Mashhad, northeast of Iran, via blood smear parasitology.

Methods

The prevalence was investigated by examination of blood smear parasitology, using blood samples collected from 254 dogs (51 strays and 203 privately owned-dogs).

Results

Two stray dogs (2/51; 3.92%) and two privately-owned dogs (2/203; 0.98%) were infected with Hepatozoon spp. Therefore, as per blood smear parasitology, the prevalence of Hepatozoon spp. infection was 1.57% (4/254). Sixteen out of 254 dogs (6.29%) were infested with ticks; all of which were Rhipicephalus sanguineus. One of the dogs infected with Hepatozoon spp. exhibited ticks at the time of examination. Concurrent infection with Ehrlichia canis and Leishmania infantum was not detected in the four Hepatozoon spp. infected dogs.

Conclusion

This is the first epidemiological study on the prevalence of Hepatozoon spp. infection in dogs in Iran.  相似文献   

20.

Background:

Free-living amoebae such as Acanthamoeba species may act as carriers of Cryptosporidium and Toxoplasma oocysts, thus, may play an important role in the water-borne transmission of these parasites. In the present study, a loop mediated isothermal amplification (LAMP) method for detection of Toxoplasma and a PCR assay were developed for investigation of Acanthamoeba in environmental water samples.

Methods:

A total of 34 samples were collected from the surface water in Guilan Province. Water samples were filtrated with membrane filters and followed by DNA extraction. PCR and LAMP methods used for detection of the protozoan parasites Acanthamoeba and Toxoplasma respectively.

Results:

Totally 30 and 2 of 34 samples were positive for Acanthamoeba and Toxoplasma oocysts respectively. Two samples were positive for both investigated parasites.

Conclusion:

The investigated water supplies, are contaminated by Toxoplasma and Acanthamoeba (oo)cystes. Acanthamoeba may play an important role in water-borne transmission of Toxoplasma in the study area. For the first time in Iran, protocol of LAMP method was used effectively for the detection of Toxoplasma in surface water samples in Iran.  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