Prevalence and tetracycline resistance profile of Salmonella typhi from local milk consumed in Yola, Adamawa State, Nigeria

Abstract

Biological contamination of food by pathogens such as Salmonella typhi is mostly caused by poor personal and public hygiene which threatens public health with foodborne diseases. This study sought to determine the prevalence of S. typhi in local milk consumed in Yola, Adamawa State, Nigeria and their tetracycline resistance profile. A total of one hundred and twenty-two milk samples were collected around the city from local milk vendors and packaged in sterile containers for analysis. Salmonella typhi was isolated from the milk samples on Salmonella Shigella agar and characterized using Polymerase Chain Reaction (PCR). Salmonella isolates were then tested for sensitivity against tetracycline using agar well diffusion method. Out of the 122 samples, only 3 (2.46%) were contaminated with S. typhi. Two out of the three 2 (67%) samples exhibited phenotypic resistance to tetracycline and only one (133%) was sensitive, implying low prevalence of S. typhi contamination. However, S. typhi is a pathogenic bacterium and its presence in food intended for human consumption is not expected. Also, the resistance exhibited by the bacteria to the most commonly used antibiotic is of public health concern.