Bacteriological and serological studies on mannheimia haemolytica infection in cattle slaughtered at Ahvaz [southwestern Iran] abattoir

In order to investigate the prevalence of Mannheimia haemolytica infection in cattle, nasal and nasopharyngeal swabs and blood samples were obtained from 250 cattle after slaughter at Ahvaz [southwestern Iran] abattoir. Nasal and nasopharyngeal swabs were cultured on blood agar and incubated at 37 [degree sign] C for 24-48 h. The suspected bacterial cultures were processed for isolation of M. haemolytica following routine bacteriological techniques. Sera were tested by indirect hemagglutination test [IHA] to reveal antibodies against the organism. M. haemolytica was isolated from 1.6% of the samples cattle. Statistical analysis showed that there was no relationship between age and sex with bacterial infection. Serological studies showed that 71.6% of tested sera contained antibody [titer >/= 1/16] against M. haemolytica. There was no association between age and sex with serological results

Study on the prevalence of Pasteurella multocida carriers in slaughtered cattle and relationship with their immunity status at Ahvaz abattoir

This study was carried out on 250 slaughtered cattle at Ahvaz abattoir in Khouzestan province of Iran to investigate the occurrence of Pasteurella multocida carriers and relationship with their immunity status. Nasopharyngeal swabs and 10 ml blood samples were taken immediately after slaughter. The swabs were streaked on 5% sheep blood agar plates. Cultures were incubated at 37°C for 24h and the plates were examined for colonies resembling P. multocida. Suspicious colonies were further subcultivated and examined microscopically and biochemically. The isolates were serotyped serologically and their pathogenicity in mice was carried out. Sera samples were tested for the presence of antibody against P. multocida by indirect haemagglutination [IHA] test and sera with a titer of >/= 1:16 were considered as positive. P. multocida was isolated from the nasopharynx of 6 [2.4%] out of 247 healthy cattle examined. There was no relation between infection and sex or age. All of 6 isolates belonged to type B. They were pathogenic for mice and caused death in injected mice within less than 24h after injection. Indirect haemagglutination test revealed the titers of >/= 1:16 of P. multocida antibody in 212 [84.8%] cattle. Among 6 cattle recognized as the carriers of P. multocida, 5 were positive serologically and 2, 2 and one of them had titers 1:128, 1:64, and 1:32, respectively