An investigation into the incidence of E. coli bacterial infections linked to outbreaks of rabbit diarrhea was carried out using a field survey. Ninety samples were recovered from diseased and freshly dead rabbits, suffering from diarrhea , from Kafrelsheikh governorate farms. Samples of fecal swabs and Internal organs, including the liver, spleen, and intestinal contents, were aseptically collected, and E. coli was isolated and identified by traditional method. E.coli was typed serologically and tested for antimicrobial agents. E.coli infection incidence rate was (66.6%). Moreover, the serologically identified of seven E. coli isolates were three O91, two O128 ,one O17 and one O44 .All bacterial isolates were highly sensitive to Ciprofloxacin , Amikacin, and Fosfomycin by 100% , while tetracycline and streptomycin resistance was present in 90% and 40% of the strains, respectively. The isolates were screened for presence of cnf1 and tsh virulence genes, qnrA and tetA(A) antibiotic resistance genes . Six weeks-old thirty healthy rabbits were used , fecal swabs were taken to make sure that rabbits free from E.coli . Rabbits were divided into 5 groups (6 rabbits for each) ; Group 1 were kept as negative control (without infection) , Group 2,3,4,5 were inoculated orally with 1 ml of culture (1x107 CFU/ml) , Group 2 were kept as positive control (without treatment)and tested for the virulence by expermintal examination , Group 3 were treated with ciprofloxacin 2 days after infection for 5 successive days , Group 4 treated with acetic acid 2 days after infection for 5 successive days , while Group 5 were treated with ciprofloxacin and acetic acid 2 days after infection for 5 successive days . All animals were kept for 21 days (period of observation) with daily examination for clinical signs, mortality rate and gross P.M. lesions in dead animals till the end of the observation period and trials of reisolation were conducted .
Aim of the work
The principal objective of the research was to find out the incidence of E. coli is in young rabbits in the Egyptian governorate of Kafrelsheikh. The polymerase chain reaction (PCR) was also used to investigate the presence of certain virulence and antibiotic resistance genes in the isolated E. coli strains. Acetic acid alone and acetic acid with antibiotic were used as trials for treatment of artificially infected rabbits with E.coli .