Humans In Iran Research Articles

Determine the prevalence of Brucella spp. and Leptospira spp. in blood samples by multiplex polymerase chain reaction collected from cattle, sheep and goats in herds located in provinces of Iran

Leptospirosis and brucellosis are common zoonosis that affect many species of mammals mostly causing economical losses. Further, very important fact is huge danger for human and animal health around the world. The purpose of the study is to determine the prevalence of <em>Brucella</em> spp. and <em>Leptospira</em> spp. using multiplex polymerase chain reaction (mPCR) method, in blood samples collected from cattle, sheep and goats. In this study, a total number of 250 blood samples (5 cc of blood with ethilen diamin tetra asetic acid) were collected randomly from 100 cattle, 80 sheep and 70 goats located on 6 herds in Chaharmahal Va Bakhtiari and Esfahan provinces, Iran. After DNA extraction and setting of mPCR for <em>Brucella</em> spp. and <em>Leptospira</em> spp. mPCR products were screened. The DNA of these microorganisms was detected by multiplex PCR from 31 and 21 out of 100 cattle, respectively. Four of 70 goat’s blood samples from goat breeding farms were positive for <em>Leptospira</em> spp. and 11 were positive for <em>Brucella</em> spp. Out of 80 sheep blood samples 23 were positive for <em>Brucella</em> spp. and 14 for <em>Leptospira</em> spp. The results of the present study show ruminant as an important reservoir for transmission of these zoonotic diseases to humans in Iran. mPCR has the ability to concurrently detect both Brucella and Leptospira species from blood samples of ruminants. The convenience and the possibility of detection of both bacteria at a time, strongly support the use of this mPCR for routine diagnostics.

The importance of subtype analysis of Cryptosporidium spp. in epidemiological investigations of human cryptosporidiosis in Iran and other Mideast countries.

The importance of subtype analysis of Cryptosporidium spp. in epidemiological investigations of human cryptosporidiosis in Iran and other Mideast countries.

Dermatophytes as a cause of epizoonoses in dairy cattle and humans in Iran: epidemiological and clinical aspects

Zoophilic dermatophytosis is a major public and veterinary health problem globally widespread among cattle. To identify the causative agent and geographical distribution of dermatophytes involved in cattle ringworm and to establish if they would be related to human diseases in Iran, a study was carried out on 6789 heads of cows and 130 herdsmen during 2006-2007. Samples were taken from 380 cattle and 43 herdsmen with suspected dermatophytosis. The causative agents were identified macroscopically and microscopically by KOH examination and culture isolation. Only 352 cases of dermatophytosis were identified in cattle and Trichophyton verrucosum was the exclusive fungus isolated from animals. Moreover, 27 cases of human dermatophytosis were identified and T.verrucosum was the prevalent causative agent for dermatophytosis in the body, scalp, foot, nail and groin of the patients. The obtained results showed that T. verrucosum was the predominant cause of dermatophytosis in livestock and dairy farmers. There is a scarcity of information on isolation and identification of the epizoonotic agents of dermatophytoses in cattle in Iran. This study showed the occurrence of dermatophytosis in humans and cattle and confirms that the dermatozoonoses are responsible for predominant forms of the disease in people who were in contact with cattle.

Evaluation of Different Methods for Diagnosis of Dirofilaria immitis

Dirofilaria immitis, a common parasite of the cardiovascular system of the carnivores all over the world, is reported from dogs, cats and, humans in Iran. Knott method is the most common test for its diagnosis in many regions including Iran. In the present study, during one year period from 2002 to 2003, blood samples of 110 dogs were examined using modified Knott method and commercial antigen detect test kit (WITNESS CHW II kit). All dogs were subjected to necropsy to evaluate the specificity and sensitivity of both tests. In Knott method, 22 harbored dogs (20%) were microfilaraemic of which (of the first instance), 20 dogs (18.18%) D. immitis and 2 (1.82%) D. reconditum. Accordingly, by using commercial antigen detection test kit 16 dogs (14.54%) were found to be infected with D. immitis. At necropsy 14 out of 110 dogs (12.73%) harbored D. immitis in the right ventricle of the heart. Thus, it was concluded that 6 out of 20 positive dogs with D. immitis were microfilaraemic and these microfilaria belonged to other filarial except D. immitis. To compare the findings with golden test (necropsy), the sensitivity and specificity of Knott and antigen detection test were 85.71 and 91.66%, 92.85 and 96.87%, respectively. McNemar test showed that although sensitivity of the latter was higher, differences were not significant (p > 0.05).

Prevalence of Cryptosporidium sp. infection in diarrheic and non-diarrheic humans in Iran

For evaluation of the prevalence of Cryptosporidium sp. infection in diarrheic and non-diarrheic humans in Iran, fecal specimens from diarrheic (n = 129) and non-diarrheic humans (n = 271) were collected and examined for the presence of Cryptosporidium sp. oocysts. The presence of Cryptosporidium sp. oocysts was determined by Ziehl- Neelsen acid-fast staining. Humans were grouped according to their age as follows: younger than 15, 16-25, 26-35, 36-50, and over 51 years. The results showed that the overall prevalence of infection in all 400 samples was 10.8%, but the prevalence (25.6%) in diarrheic humans was higher than that (3.7%) in non-diarrheic humans. Oocysts of Cryptosporidium sp. were detected in the feces of 21.4%, 9.3%, 8.8%, 6.7% and 5.7% of different age groups, respectively. The intensity of oocysts was significantly higher in diarrheic humans than in non-diarrheic ones. There was a significant association between Cryptosporidium sp. infection and occurrence of diarrhea (P < 0.05). The results indicate that Cryptosporidium sp. infection is prevalent in diarrheic humans in Iran.

Detection of the cytolethal distending toxin locus cdtB among diarrheagenic Escherichia coli isolates from humans in Iran

Cytolethal distending toxin (CDT) represents an emerging family of newly described bacterial products that are produced by a number of pathogens. Genes encoding this toxin were identified as a cluster of three adjacent genes, cdt-A, cdt-B and cdt-C. Five cdt genetic variants, designated cdt-I, cdt-II, cdt-III, cdt-IV and cdt-V, have been identified so far. To determine the presence of cdt genes among Escherichia coli isolates, a PCR assay was employed. Using multiplex primers designed for detection of E. coli cdt genes, PCR analysis indicated the presence of cdt genes in 37.5% of these isolates. While specific primers were located in the cdt-B locus for detection of cdt-I, cdt-II, cdt-III and cdt-IV, in multiplex PCR positive isolates indicated that a cdt-I-like gene was present in 45.3% of these isolates. However, in 52% of the isolates, the cdt-III-like gene could be detected. It should be mentioned that in 30.8% of these isolates, cdt-II and - III were detected simultaneously. In 2.6% of the isolates, the cdt-IV gene was present. The cnf-1 gene was detected in 29.4% of strains carrying the cdt-I gene; however, the cnf-2 gene was detected only in 23.1% of the cdt-III-like strains. Furthermore, the data obtained by PCR analysis indicated the presence of cdt-like genes among our E. coli isolates, although in the CHO cell assay, all isolates showed a cytopathic effect characteristic of CDT.

Asymptomatic cryptosporidiosis in cattle and humans in Iran

Asymptomatic cryptosporidiosis in cattle and humans in Iran