PUBLIC HEALTH RISK OF LISTERIA MONOCYTOGENES IN RAW MILK IN EGYPT: VIRULENCE GENES, ANTIBIOTIC-RESISTANCE AND HIGH-RISK CONSUMPTION PRACTICES

Listeria monocytogenes is an important food-borne pathogen with serious complications in humans. Despite of its public health importance, studies on L. monocytogenes are scarce in Egypt. This study aimed to investigate the public health risk of L. monocytogenes in raw milk with regard to prevalence, virulence, antibiotic resistance and high-risk consumption practices. A total of 200 milk samples were collected and L. monocytogenes was detected in 2% of all samples. On species level, L. monocytogenes was isolated from 4% of sheep, 2% of goats, 2% of cows but not from camel milk samples. Molecular analysis showed that inlA, inlB and hlyA virulence genes were detected in 100%, 75% and 75% of the isolates, respectively. All isolates were multi-drug resistant (MDR) to at least 4 antibiotics. Livestock owners’ responses with regard to their consumption practices revealed that 62.1% of respondents consume raw milk, 100% of them don’t boil milk before dairy processing and 27.1% of them were willing to drink milk from morbid animals. All of these practices are considered of high-risk for transmission of milk-borne pathogens. The high rates of L. monocytogenes detection in milk imply unhygienic milk production. The virulence and antibiotic resistance profiles of isolates may pose a potential high risk for the milk consumers in the study region. Continuous monitoring of virulence and antibiotic resistance traits of L. monocytogenes pathogens is necessary for accurate risk evaluation and designing of preventive measures in Egypt. Public health education campaigns regarding hygienic milk production and risks of milk-borne pathogens are urgently needed for improving the awareness and reduce the high-risk consumption practices in residents of the study region.