Abstract
Aim:This study was undertaken to isolate Listeria (L.) species from raw meats sold in markets in Enugu State, Southeast Nigeria, and to determine the antibacterial resistance profile.Materials and Methods:Twenty-five grams of beef (n=144), chicken meat (n=144), and pork (n=144) were collected randomly from supermarkets and general markets in Enugu State. Isolation of Listeria was done using half and full Fraser broths, and polymyxin acriflavine lithium chloride ceftazidime aesculin mannitol agar. Identification of isolates was done using an analytical profile index kit specific for Listeria. Confirmation of the genus Listeria was done by a polymerase chain reaction. The resistance of the isolates was determined using the disk diffusion method.Results:Listeria was isolated from 39/144 (27.1%) chicken meat, 19/144 (13.2%) pork, and 66/144 (45.8%) beef samples cultured. Listeria innocua was the predominant species in chicken meat (52.6%) and beef (81.8%) samples. Listeria grayi, Listeria welshimeri, and Listeria ivanovii were also isolated from the beef and chicken meat samples. More than 65% of the isolates were resistant to penicillin, rifampicin, ciprofloxacin, sulfamethoxazole-trimethoprim, and cephalothin. All the isolates from beef and pork samples and 23 (92%) from chicken meat samples, were resistant to ≥3 classes of antibacterial agents. Mean multiple antibiotic resistance index (MARI) was 0.77 (range=0.42-1.00), 0.58 (range=0.25-0.83), and 0.79 (range=0.58-0.92) for the isolates from beef, chicken meat, and pork samples, respectively. All the isolates had MARI >0.2.Conclusion:Multidrug-resistant Listeria strains contaminate raw beef, pork, and chicken meats marketed in Enugu State, Southeast Nigeria.
Highlights
Listeria species are Gram-positive rods constituting part of normal commensal flora in the gut of humans and animals [1]
Two of the L. grayi isolates and one L. innocua strain were obtained from two samples; all the L. welshimeri strains were isolated together with L. innocua in four samples whereas two L. ivanovii and two L. grayi strains were recovered from two different samples
Table-4: Multiple antibacterial resistance patterns and indices of 25 Listeria isolates from raw chicken meats marketed in Enugu State Southeast Nigeria
Summary
Listeria species are Gram-positive rods constituting part of normal commensal flora in the gut of humans and animals [1]. Due to their virulence attributes (biofilm formation, invasion and survival in host’s phagocytic cells, and so on), Listeria species are facultatively pathogenic and they are associated with zoonotic foodborne infections (generally termed listeriosis) worldwide [2]. The recent outbreak of listeriosis in South Africa (2017-2018) which accounted for 27% mortality (World Health Organization [WHO], 2018) [5], rekindled the interest in occurrence of Listeria species especially the antibacterial-resistant (ABR) strains, in foods of animal origin in developing countries [2,5].
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call