Identification and characterisation of the common aetiologies of cattle respiratory diseases in Mahikeng local municipality, South Africa
Abstract
Bovine respiratory disease (BRO) is one of the most significant health problems in the livestock sector worldwide, resulting in significant economic losses for the livestock industry. Several studies have addressed BRO prevalence in cattle worldwide, including South Africa. Nevertheless, the common pathogenic causes of BRO in the Mahikeng local municipality cattle (North West Province) is unknown. The aim of this study was to determine the common pathogens involved in BRO in Mahikeng local municipality. Following their identification, the bacterial pathogens were evaluated to suggest suitable antibiotic treatment. Two hundred (blood and nasal discharge) samples were collected from cattle showing signs of respiratory distress in different
communal areas. Serum samples were tested for antibodies to Infectious Bovine Rhinotracheitis (IBR), Bovine Viral Diarrhoea Virus(BVDV), and Bovine Parainfluenza Virus type 3(Pl3V) using ELISA. Conventional Polymerase Chain Reaction (PCR) was used to identify the bacteria and the endpoint of PCR assay was sent for sequencing
analysis. Following identification, 6-disc diffusion containing different antimicrobials were used to evaluate isolates antimicrobial susceptibility. According to ELISA results, 71 .8% of samples were positive to Bovine Parainfluenza Virus type 3 followed by Infectious Bovine Rhinotracheitis (68.2%) and Bovine Viral Diarrhoea Virus (60%). Sequence analysis of the isolates in this study were closely related to NCBI-BLAST isolates; Escherichia coli, Shigel/a dysenteriae, Escherichia coli 0145, Listeria welshimeri, Neisseria spp., Enterococcus casseliflavus, Enterobacter cancerogenus, Corynebacterium cal/unae, Clostridium pasteurianum and Kosakonia cowanii. There were high levels of resistance against Gentamicin (96.8%), Chloramphenicol (93.7%), and Penicillin G (88.2%) whereas 87.3% of isolates showed resistance to Norfloxacin. In addition, E. coli were at least susceptible to all the antimicrobial tested . Chi-Square test results showed that there was statistically significant (p-value < 0.05) association between the antimicrobials and antimicrobial resistance. The findings of this study
demonstrate that BVDV, IBR, and Pl3V are common viruses causing BRO in Mahikeng local municipality and control measures to prevent economic losses to the cattle industry are important.