Molecular serotyping and antimicrobial susceptibility profiles of Pasteurella multocida isolated from cases of hemorrhagic septicemia in cattle from selected districts of Keffa and Bench Sheko zones, South West Ethiopia

Abstract

BACKGROUND: Hemorrhagic septicemia is a highly fatal disease of cattle caused by the bacteria; Pasteurella multocida serotypes B and E in Asia and Africa respectively. Even though the capsular serotype E is considered to be the common cause of Hemorrhagic septicemia in Africa, there is not enough evidence that other serotypes are not involved. Furthermore, the serotypes currently circulating in South West Ethiopia have not been identified. This study was carried out to identify circulating capsular serotypes of Pasteurella multocida and assess its antimicrobial resistance on hemorrhagic Septicemic cattle through bacterial isolation, molecular identifications, and antimicrobial susceptibility tests in Keffa and Bench Sheko Zones of South West Ethiopia Peoples' Regional State. RESULTS: The bacteriological analysis from 45 purposively collected nasopharyngeal swab samples of hemorrhagic Septicemic cattle revealed that 12 (26.7%) isolates were identified as Pasteurella multocida. Similarly, the molecular analysis of these isolates revealed all twelve (12) isolates were confirmed to be Pasteurella multocida. On further capsular typing, serotype B (n = 5, 41.6%) and E (n = 5, 41.6%) were the confirmed circulating strains in the area while two (n = 2, 16.6%) isolates formed non-specific bands. All the Pasteurella multocida isolates were susceptible to Gentamicin (100%), Chloramphenicol (100%), Oxytetracycline (91.7%), and Streptomycin (75%). However, all the isolates showed multidrug resistance (100%), to four antibiotics "Ampicillin, Clindamycin, Penicillin-G, and Vancomycin". CONCLUSIONS: Molecular analysis of the study isolates confirmed serotypes B and E as the etiology for Hemorrhagic septicemia in cattle in the study area. A multivalent vaccine comprising serotypes B and E is recommended to prevent outbreaks along with early treatment of suspected cases during the pyretic stage using antibiotics that are effective against the strains.