Epidemiology and control of genital pasteurellosis in breeding rabbits

This study aimed to investigate the epidemiology and the possible ways of control of Pasteurella multocida (P. multocida) microorganism as a genital and a respiratory pathogen in rabbit bucks during the period from 2012-2016. Two hundred semen and nasal samples randomly collected from 23-35-week-old apparently healthy breeding bucks representing 30 rabbit farms located in different districts at Giza Governorate. The examined rabbit bucks suffered from low reproductive activity. Serological identification was performed by using slide agglutination test (SAT), gel-diffusion precipitin test (GDPT) and enzyme linked immunosorbant assay (ELISA). Molecular identification of the isolated strains was performed using polymerase chain reaction (PCR). The correlation between the presences of P. multocida and reproductive disorders in rabbit bucks was investigated by measuring semen parameters (advanced sperm motility %, live spermatozoa %, Sperm concentration x 106 / ml and sperm abnormalities %) in alternative husbandry systems. The results revealed that isolation of 7 isolates of P. multocida with an incidence of 3.5 %. The in vitro antibiotic sensitivity test revealed that the isolated strains were highly sensitive to thiamphenicole, gentamycin, ciprofloxacin, amoxycillin, amoxycillin + clavulanic acid, clindamycin, colistin sulphate, tetracycline, enrofloxacin, lincomycin and vancomycin and moderately sensitive to neomycin and oxytetracycline. On the other hand isolates were resistant to ampicillin, erythromycin, penicillin G, sulphamethozole-trimethoprim and streptomycin. Experimental infection of 6-8-month-old rabbit bucks with isolated strain (A: 12) of P. multocida from semen followed by treatment trials using thiamphenicole and gentamycin with ciprofloxacin were carried out. Clinical signs, postmortem gross lesions and semen evaluation with re-isolation of P. multocida strains in pure form were discussed in details. Histopathological examination of tissue sections from different organs of experimentally infected bucks revealed less severe lesions after treatment with thiamphenicole and gentamycin with ciprofloxacin, when compared with infected non treated rabbit groups.