Risk factors associated with E. coli causing neonatal calf diarrhea.

Calf diarrhea is one of the major health challenges in cattle herds. The bacteriological examination of fecal samples collected from apparently healthy and diarrheic calves' revealed isolation of 26 E. coli isolates out of 56 calves with an incidence of 46.4%. Serogroups O1, O26, O44, O55, O115, O119, O125, O146, and O151 were identified from the collected fecal samples. Using PCR all isolates was positive for ompA gene species specific for E. coli. While stx1 and eaeA genes detected with incidence of 3.8 and 19.2% respectively from the isolates. The presence of stx2 gene was negative in the fecal isolates. Among colostrum samples 4 E. coli isolates were detected and serogrouped to O26, O55 and O119. They were negative for eaeA, stx1 and stx2 except strain number 4 (O55) was positive for stx1. E. coli strains were sensitive to norfloxacin (80.7%) and resistant to ampicillin and cefotaxime (100% each). Based on our findings, there was no association between occurrence of E. coli and age of calf (2-14 days), while bottle feeding calf colostrum may be a source of E. coli contamination.

Isolation of antimicrobial producing Actinobacteria from soil samples.

Emergence of multidrug resistant bacteria has made the search for novel bioactive compounds from natural and unexplored habitats a necessity. Actinobacteria have important bioactive substances. The present study investigated antimicrobial activity of Actinobacteria isolated from soil samples of Egypt. One hundred samples were collected from agricultural farming soil of different governorates. Twelve isolates have produced activity against the tested microorganisms (S. aureus, Bacillus cereus, E. coli, K. pneumoniae, P. aeruginosa, S. Typhi, C. albicans, A. niger and A. flavus). By VITEK 2 system version: 07.01 the 12 isolates were identified as Kocuria kristinae, Kocuria rosea, Streptomyces griseus, Streptomyces flaveolus and Actinobacteria. Using ethyl acetate extraction method the isolates culture's supernatants were tested by diffusion method against indicator microorganisms. These results indicate that Actinobacteria isolated from Egypt farms could be sources of antimicrobial bioactive substances.

Preparation of goat and rabbit anti-camel immunoglobulin G whole molecule labeled with horseradish peroxidase.

AIM: As the labeled anti-camel immunoglobulins (Igs) with enzymes for enzyme-linked immunosorbent assay (ELISA) are unavailable in the Egyptian market, the present investigation was directed for developing local labeled anti-camel IgG with horseradish peroxidase (HRP) to save hard curacy. MATERIALS AND METHODS: For purification of camel IgG whole molecule, camel sera was preliminary precipitated with 50% saturated ammonium sulfate and dialyzed against 15 mM phosphate-buffered saline pH 7.2 then concentrated. This preparation was further purified by protein A sepharose affinity column chromatography. The purity of the eluted camel IgG was tested by sodium dodecyl sulfate polyacrylamide gel electrophoresi. Anti-camel IgG was prepared by immunization of goats and rabbits separately, with purified camel IgG. The anti-camel IgG was purified by protein A sepharose affinity column chromatography. Whole molecule anti-camel IgG was conjugated with HRP using glutraldehyde based assay. Sensitivity and specificity of prepared conjugated secondary antibodies were detected using positive and negative camel serum samples reacted with different antigens in ELISA, respectively. The potency of prepared conjugated antibodies was evaluated compared with protein A HRP. The stability of the conjugate at -20°C during 1 year was assessed by ELISA. RESULTS: The electrophoretic profile of camel IgG showed four bands of molecular weight 63, 52, 40 and 33 kDa. The recorded sensitivity and specificity of the product are 100%. Its potency is also 100% compared to 58-75% of commercial protein A HRP. The conjugates are stable for 1 year at -20°C as proved by ELISA. CONCLUSION: Collectively, this study introduces goat and rabbit anti-camel IgG whole molecules with simple, inexpensive method, with 100% sensitivity, 100% specificity and stability up to 1 year at -20°C. The important facet of the current study is saving hard curacy. Future investigations are necessary for preparation of IgG subclasses.