Determination of some Virulence Factors of Pasteurella multocia isolated from Human and Farm Animals infections

Abstract

Twenty one Isolates of Pasteurella multocida were obtained from different clinical specimens of human and farm animals' infections. Human specimens included wounds swabs taken after cats and dog's bits beside the urine and sputum samples. The animal samples were nasal swabs and blood samples taken from chattels, also the poultry tissues of infected chicken with fowl cholera were collected. Bacterial isolates were isolated using Pasteurella multocida selective agar (PMSA) then identified doing different morphological, biochemical tests followed by api 20E diagnosis. The ability of the bacterial isolates to produce different virulence factors were studied, 18 isolates 85.7% were able to produce Lipase enzyme. Results of pathogenicity study on Lab. animals (mice) showed that there were 9 highly virulent isolates among the 21 (42.8%). The killing time was in between (10-24) hrs after injected the mice’s intraperitoneally. Some of the isolates showed their ability to produce the dermonecrotic toxin and the positive result appeared as highly purulent, dermonecrotic lesions after injection Genia pig intradermally. Results of antibiotic sensitivity test revealed that there were considerable variations in isolates susceptibility. Some of the isolates were highly resisted most of the used antibiotics while others were not. The crude bacterial extract from PMA20 isolate was tested to determine its ability to stimulate human lymphocytes division in vitro, results showed that the extract was able to stimulate cells division when the mitotic index was 1.2% as compared with the positive control.