Some studies on Listeria Monocytogenes infection in buffaloes

Abstract

The present study concerned with Listeria monocytogenes which were isolated from apparently healthy buffaloes, buffaloes suffered from abortion, bedding and silage, which were collected from different localities. From the total examined samples (375), (300 samples from apparently healthy buffaloes, bedding and silage, also 75 samples from buffaloes suffered from abortion , bedding and silage) the prevalence of L. monocytogenes was 11(14.7%), isolates from buffaloes suffered from abortion, bedding and silage. All isolates were motile at room temperature, also exhibited positive CAMP test and exhibited narrow zone of β β β β-hemolysis. Serological identification of isolates revealed 6(54.5%) were serotype 4 while 5(45.5%) were untyped. There were differences in isolates susceptibilities to different anti-microbial agents. L. monocytogenes had 100% sensitivity to Ampicillin, chloramphenicol, erythromycin, tetracycline and ceftiofur sodium. Virulence of isolates was assayed by I/P inoculation of 10 9 CFU in mice, all inoculated mice died within 1-5 days. PCR assay for L. monocytogenes isolates revealed positive amplification of 827 bp fragment of act A gene.