A survey of selected pathogenic bacteria in chickens from rural households in Limpopo Province

Abstract

Salmonella enterica serovar Gallinarum biovars Gallinarum, and Pullorum, Pasteurella multocida and Escherichia coli are among the most important pathogens in poultry and are the causal agents of fowl typhoid, pullorum disease, fowl cholera and collibacillosis in poultry. The present study was designed to identify and determine the distribution of these pathogens in household-raised chickens and their antibiotic and virulence profiles. For this purpose, 40 chickens were bought from household families at Ga-Dikgale, GaMolepo and Ga-Mphahlele in the Capricorn district of Limpopo Province and sacrificed for sampling. Tissues including breast meat, lungs, small and large intestines were harvested from each chicken. Bacteria associated with these samples were cultured in selective bacteriological media followed by biotyping using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) for identification. Out of a total of 160 tissue samples evaluated, E. coli and Salmonella were detected in these tissues. Furthermore, determination of the pathogenic E. coli and Salmonella strains at species level using primer sets that target selected genes of interest in the polymerase chain reaction (PCR) assay was employed. The invA gene, a confirmatory gene for Salmonella species was detected in all the Salmonella isolates using PCR. For the pathogenic E. coli, astA, eae, hlyA, fIiCH7, stxI and the fimbrial genes (F6 and F41) were detected in some of the E. coli isolates recovered from the samples. Disk diffusion test was also performed to determine the antibiotic susceptibility of the bacteria. The results from the current samples reveals that there is a high distribution of Salmonella and pathogenic E. coli in these areas and therefore further epidemiological and identification studies are needed to determine these organisms at species level and investigate their pathogenicity. The antimicrobial susceptibly data generated from this study can be a valuable reference to veterinarians for treating bacterial diseases in poultry.