Serotayping and Sensitivity Tests of Pathogenic Escherichia Coli Isolated From Salpingitis in Commercial Laying Hens.

Abstract

Reproductive system disorders of laying hens have been gaining increasing attention due to immense economic losses that are being inflicted by these conditions on the growing poultry industry. Salpingitis is considered as an important one of these disorders. In order to determine the incidence of salpingitis in laying hens, 1050 recently dead laying hens from commercial laying farm in Assiut province were necropsied. Among thesehens, 120 (11.43%) cases showed lesions of salpingitis. Bacterial examination detected 103(85.8%) bacterial cultures from 120 suspected cases of salpingitis that yielded Esherichia coli in 46 (38.3%), Enterobacter spp in 31 (25.9%), Klebsiella spp in 11 (9.1%), Citrobacter spp in 8 (6.7%) of these cases and mixed bacteria in 7 (5.8%) cases. No bacteria were isolated from 17 (14.2%) of the suspected cases and also from normal oviducts of healthy hens. The fourty-sixE. coli isolates were serotyped and examined for susceptibility to 13 antimicrobials. O-serogroup determination test showed that the isolates belonged to nine different O serogroups including: O111, O26, O125, O55, O114, O127, O86, O124 and O142 serogroups. The most prevalent serogroups were O111, O26, O125, O55 respectively. However the maximum antimicrobial resistance of the tested E. coli isolates was demonstrated to sulfamethoxazol (100%), followed by amoxicillin (97.8%), erythromycin and oxytetracycline (89.1% for each), neomycin (87%), ampicillin (80.4%), kanamycin (67.4%) and streptomycin (60.9%), the minimal resistance was against gentamycin (2.2%) then ciprofloxacin (6.5%), norfloxacin (10.9%), nalidixic acid and lincospectin (23.9% for each). Multiple antimicrobial-resistant phenotypes (to 3 or more) were observed in 41/46 (89.1%) of E. coli isolates and one isolate was resistant to all tested drugs. The obtained results were recorded and compared with other workers results.