Molecular genotyping and epidemiology of Mycobacterium bovis strains obtained from cattle in Iran

Restriction fragment length polymorphism (RFLP) genotyping was employed to analyze the population genetics of Mycobacterium bovis in Iran. One hundred and twenty-three isolates collected from slaughtered tuberculosis-suspect cattle and one clinically asymptomatic buffalo were subjected to RFLP analysis with probes of the polymorphic GC-rich sequence (PGRS) and the direct repeat sequence (DR) using DNA digested with PvuII and AluI. All these methods detected a large homogeneous population in which only a few isolates had variant genotypes. Only AluI-based RFLPs of both the PGRS and DR sequences were able to clearly differentiate between BCG and field strains of M. bovis. As in previous reports, these findings seem to reflect a recent dispersal of one or a few strains in Iran following the substantial expansion of Holstein-Friesian cattle over the last few decades.     

A review of the contemporary knowledge of bovine tuberculosis and government policy in Iran

In 1931 Carpantier reported bovine TB (BTB) in Iranian cattle. Some eighty years on with a national test-and-slaughter programme in place for over four decades, the efforts to vanquish Mycobacterium bovis (M. bovis) infection in cattle have been in vain as the vast majority of the 30 Iranian provinces still have reports of BTB in their cattle herds every year. This paper reviews the present epidemiology of BTB in Iran and in the region and evaluates the success of government policy in controlling this disease.     

Development of Rose Bengal test against mallein test for rapid diagnosis of equine glanders

Tropical Animal Health and Production - Burkholderia mallei, the etiologic agent of the disease known as glanders. Clinical and bacteriological diagnosis of glanders is difficult in the early...     

The population structure of Salmonella enterica Enteritidis in Iran analyzed by multiple-locus variable-number tandem repeat analysis

Salmonella enterica Enteritidis is the most frequent etiological agent of salmonellosis in humans and poultry. To understand the genetic diversity of S. Enteritidis in Iran, we examined 69 chicken isolates from 18 broiler farms and six non-epidemic human isolates from six geographically distant provinces by multi-locus variable-number tandem repeat analysis (MLVA). Among SE2, SE3, SE5, SE7, SE8, SENTR4, and SENTR7, only SE5 with four and SENTR7 with two alleles, respectively, proved variable giving estimates of locus genetic diversity of 0.58 and 0. In all, six closely related MLVA profiles were identified among which three were commonly represented by human and chicken isolates. This population homogeneity contrasts with the high diversity at these loci reported elsewhere and is likely a consequence of a single clone of S. Enteritidis distributed across Iran.     

Comparison of rapid diagnostic tests to detect <Emphasis Type="Italic">Mycobacterium avium</Emphasis> subsp. <Emphasis Type="Italic">paratuberculosis</Emphasis> disseminated infection in bovine liver

Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne’s disease, a chronic enteritis in cattle and other domestic and wild ruminants. The presence of MAP in tissues other than intestines and associated lymph nodes, such as meat and liver, is a potential public health concern. In the present study, the relationship between the results of rapid diagnostic tests of the Johne’s disease, such as serum ELISA, rectal scraping PCR, and acid-fast staining, and the presence of MAP in liver was evaluated. Blood, liver, and rectal scraping samples were collected from 200 slaughtered cattle with unknown Johne’s disease status. ELISA was performed to determine the MAP antibody activity in the serum. Acid-fast staining was performed on rectal scraping samples, and PCR was performed on rectal scraping and liver samples. PCR-positive liver samples were used for mycobacterial culture. Overall, the results of this study demonstrated that MAP can be detected and cultured from liver of slaughtered cattle and rapid diagnostic tests of Johne’s disease have limited value in detecting cattle with MAP infection in liver. These findings show that the presence of MAP in liver tissue may occur in cows with negative results for rapid diagnostic tests and vice versa. Hence, liver might represent another possible risk of human exposure to MAP. Given concerns about a potential zoonotic role for MAP, these results show the necessity to find new methods for detecting cattle with MAP disseminated infection.     

The Epidemiology of Mycobacterium bovis in Buffalo in Iran

Mycobacterium bovis is the cause of bovine tuberculosis (bovine Tb) in animals and is considered to be zoonotic and accordingly it infects humans, although cattle are the main host. Buffalo can also be infected and develop bovine Tb. In Iran, almost half a million buffaloes are farmed, mainly in three provinces. In West Azerbaijan, which has the largest numbers of buffaloes, cattle and buffalo are often farmed together. According to the reports of the Iranian Veterinary Organization over the last 25 years, there have been no reports of bovine Tb in buffalo, although the disease is often reported in cattle in this province. Eighteen and 140 pathology specimens from cattle and buffalo, respectively, collected from West Azerbaijani abattoirs were cultured. From one buffalo specimen out of 140, M. bovis was recovered, whereas the pathogen was isolated from 13 cattle specimens. Spoligotyping showed a relatively higher polymorphism within these isolates compared with M. bovis isolated from other Iranian provinces.     

Paratuberculosis in Holstein-Friesian cattle farms in Central Iran

Paratuberculosis is an important disease of ruminants with a worldwide distribution. In developing countries where funding constraints challenge establishment of control schemes, large losses are incurred on cattle farmers due to paratuberculosis. In this study, faecal specimens from Holstein-Friesian cows with progressed and moderate clinical paratuberculosis (N = 223) from 13 dairy farms in Isfahan, Central Iran, were subjected to bacterial culture. Culture growth diagnostic for M. avium subsp. paratuberculosis was found in cattle from nine of the 13 farms and in 71 of the cattle studied. These results illustrate the emergence of PTb in this region, and they imply that PTb should be given a higher priority for veterinary measures.