[Application of micro agglutination test in detecting serovars of leptospira]

Leptospirosis is an infectious and zoonosis disease, which is caused by leptospira and is transmitted from animal to human. The rapid diagnosis can control the disease, therefore this study was carried out to determine the prevalent serovars of leptospira using micro agglutination test [MAT] in human and cattles. In this descriptive study, 175 cattles and 67 suspected human serum samples were tested in five provinces in Iran during 2011-12. Serum samples tested by micro agglutination test using 20 live leptospira serogroup. Ninty nine out of 175 [56.5%] cattle serum samples and 31 out of 67 [46.2%] human samples were positive against leptospira antigen. The most prevalent leptospira serovar in cattles and human were Serjoe hardjo [61.9%] and Serjoe serjoe [23%], respectively. The most frequent titer in positive samples was equal to be 1/400. Fifty percent of human positive samples belong to farmers between 20-40 years old. The common contaminations belong to polluted water [61.1%] and infected blood [28.3%], respectively. Using micro agglutination test, the most prevalent leptospira serovar in cattles was Serjoe hardjo and in human was Serjoe serjoe

Hyperimmune lipopolysaccharide antiserum mediated inhibition of the adherence of E. coli O157:H7 to HEP-2 cells and large intestine of mice

Escherichia coli O157:H7 is found in cattle farms and can live in the intestine of healthy cattle. Most cases of human illnesses including nonbloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome can be traced, either directly or indirectly, to cattle. One strategy for reducing the risk of Enterohemorrhagic Escherichia coli [EHEC] infections in human is to reduce the prevalence of infection in cattle. Antiserum against whole cell of isolated E. coli O157:H7 from cattle showed inhibition of adherence of this strain to HEP-2 cells in 1:1280 titer and to intestine tissue of mice in 1:640 titer are significant. histology of intestine tissue confirms our results. The difference between in vivo and in vitro titrations for blocking the attachments depends on these two different conditions

[Molecular study of phase variation of type 1 fimbriae in uropathogenic escherichia coli 044 serotypes during touching with solid surfaces]

Type 1 fimbriae is the most common adhesion factor in urine tract infection. In this Study, presence of virulence genes in isolated strains of uropathogenic E. Coli, O serotyping and molecular detection of phase variation of type 1 fimbriae were assessed during solid surfaces exposure. Isolated E. coli from urine samples of patients were serotyped by using serologic methods. Phenotypic estimation of phase variation was applied by mannose - resistant hemagglutination [MRHA]. Fim opron phase variation was studied by HinFI digestion and PCR reaction. For all 158 E. coli strains, the most occurrences belonged to O44. Forty nine percent of the isolates were mannose-sensitive and expressed fim operon in agar medium. While, 51% of strains were resistant to mannose in the same position. In Broth medium 68% of isolates were mannose-sensitive and 32% were mannose-resistant. PCR products with 359bp and 200bp long fragment demonstrated ON position and those with 489bp and 70bp long fragment indicated ON and OFF positions. Uropathologic E. coli strains posses few number of O serotypes. Environmental factors play an important role in regulation of fimberiae operon expression. Strains recovered from these urine samples, however, were shown capable to switch the fim operon to the ON position after culture in broth medium. Type 1 fimbrial expression and flagella motility are probably representative of an essential dynamic interplay between bacterial adhesion and motility. The strains present in urine samples but nonattached to the epithelium are inactive for type 1 fimbriae expression