Serotyping, antibiogram, and detection of bacterial pathogens associated with bovine respiratory disease in selected areas of Ethiopia

Mirtneh Akalu; BhadraMurthy Vemulapati; Takele Abayneh; Teferi Degefa; Getaw Deresse; Esayas Gelaye

doi:10.1186/s13620-022-00210-z

Serotyping, antibiogram, and detection of bacterial pathogens associated with bovine respiratory disease in selected areas of Ethiopia

Ir Vet J. 2022 Mar 3;75(1):3. doi: 10.1186/s13620-022-00210-z.

Authors

Mirtneh Akalu^{1

2}, BhadraMurthy Vemulapati³, Takele Abayneh⁴, Teferi Degefa⁴, Getaw Deresse⁴, Esayas Gelaye⁴

Affiliations

¹ Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Gunture, 522502, India. mirtneh2010@gmail.com.
² National Veterinary Institute, P.O.Box: 19, Bishoftu, Oromia, Ethiopia. mirtneh2010@gmail.com.
³ Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Gunture, 522502, India.
⁴ National Veterinary Institute, P.O.Box: 19, Bishoftu, Oromia, Ethiopia.

Abstract

Background: Bovine Respiratory Disease (BRD) is a multifactorial and economically important illness of cattle. The current study was designed to characterize the major bacterial pathogens associated with BRD and determine the antibiotic susceptibility patterns of isolates. Samples were collected from 400 pneumonic cases of cattle.

Results: Laboratory assay revealed isolation of 376 (94.0%) bacterial pathogens. The most prevalent bacterial pathogens recovered were Mannheimia haemolytica (M. haemolytica) followed by Pasteurella multocida (P. multocida), Histophilus somni (H. somni), and Bibersteinia trehalosi (B. trehalosi) from 191 (50.80%), 81 (21.54%), 56 (14.89%), and 48 (12.77%) samples, respectively. M. haemolytica strains were confirmed using multiplex PCR assay through the amplification of PHSSA (~ 325 bp) and Rpt2 (~ 1022 bp) genes. Capsular typing of P. multocida revealed amplification of serogroup A (hyaD-hyaC) gene (~ 1044 bp) and serogroup D (dcbF) gene (~ 657 bp). B. trehalosi isolates displayed amplification of the sodA gene (~ 144 bp). Besides, serotyping of M. haemolytica showed the distribution of serotype A:1 (82.20%), A:2 (10.47%), and A:6 (7.33%). Whereas, biotyping of P. multocida revealed a higher prevalence of biotype A:3 (83.95%), then A:1 (8.64%), A:2 (4.94%), and A:12 (2.47%). The majority of the retrieved isolates showed remarkable susceptibility to enrofloxacin, ciprofloxacin, sulfamethoxazole-trimethoprim, florfenicol, and ceftiofur (100%). Besides, varying degree of antimicrobial resistance was observed against streptomycin, gentamicin, penicillin-G, and ampicillin.

Conclusions: The current findings confirmed that M. haemolytica (A:1) strain is the most common bacterial pathogen identified from BRD cases in the study areas of Ethiopia. Hence, continuous outbreak monitoring and evaluation of antibiotics susceptibility patterns of bacterial pathogens associated with BRD are indispensable to reduce the impact of BRD in the study areas. Further investigation of bacterial pathogens and genotypic analysis of pathogens from a wider area of the country is essential to design a cost-efficient control strategy.

Keywords: Antibiogram; Ethiopia; H; M. haemolytica; P. multocida; Serotype; somni.