Molecular characterization of Pasteurella species isolated from slaughtered cattle in Assiut abattoirs and molecular detection of some antibiotic resistance genes

Pasteurella multocida (P. multocida) is one of the most predominant pathogenic bacterial agents causing respiratory diseases in different types of animals with considerable economic losses and unfavorable prognosis in Egypt. Recently, P. multocida has exhibited resistance to the most used antibiotics in the veterinary field. So, this study was carried out to investigate the prevalence of both virulence and antibiotic resistance genes among P. multocida isolated from apparently healthy and diseased bovine lungs. Only 10 out of 60 lung samples were collected from the different slaughterhouses and just 9 were confirmed finally positive for P. multocida by PCR using Kmt1. Antibiotic susceptibility testing of the recovered isolates revealed that they were all multidrug/resistant (MDR) with a predominance of resistance to erythromycin (100%) and most of them by (90 and 80 %) for amoxicillin and doxycycline, respectively; followed by 60 and 50 for ceftriaxone, gentamicin. All of the obtained isolates were promoting consistency through PCR screening for a few relevant common antibiotic resistance genes. All MDR P. multocida isolates had at least one gene for antibiotic resistance, mostly AphA1 and BlaROB1 (100%), and only 60% of them had the ermX gene. Antibiotic resistance genotyping showed that the majority of the isolates, (60%) of isolates, having three genes producing identical resistance phenotypes had multiple antibiotic resistance genes. Our results demonstrated that pathogenic P. multocida strains carrying virulence and antibiotic resistance genes may originate from cattle. Therefore, it is evident that there is an urgent need for the judicious use of antibiotics in bovine treatment systems to successfully mitigate the propagation of drug resistance across P. multocida species.