Assessment of multidrug-resistant Listeria monocytogenes in milk and milk product and One Health perspective

Abstract

The occurrence and the antibiogram signatures of Listeria monocytogenes (Lm) recovered from 65 milk samples and its products within the Eastern Cape province were examined. The EN ISO 11290:2017 procedures Parts 1 and 2 described by the International Organization for Standardization for the enumeration and isolation of Lm was adopted for the study. Lm was detected in 18.46% of all the samples examined, and the strains recovered from the samples belong to serotypes 4b and 1/2b. The virulence determinants including prfA, plcA, plcB, inlA, inlC, hly, mpl, actA, inlJ and inlB were detected in all the isolates. About 95.24% of the studied Lm isolates demonstrated potential capacity for biofilm formation. The antibiogram profile revealed high resistance against sulfamethoxazole (71.43%), trimethoprim (52.86%); erythromycin, cefotetan and oxytetracycline (42.86% respectively). About 85.71% exhibited multiple antibiotic resistance phenotypes against the test antibiotics. The resistance determinants encoding resistance against the β-lactamase antibiotics [such as the blaTEM, blaSHV, blaTEM variants (TEM-1 and TEM-2) and the blaZ], the tetracycline resistance genes (including tetA, tetD, tetG and tetM and tetK) were detected among resistant isolates. In addition, the aminoglycoside resistance gene aph (3)-IIa (aphA2)a was detected only in one isolate. Finally, the sulfonamide resistance genes including the sul2 and the sul1 genes were the most frequently observed among Lm isolates. Generally, 71.43% of all Lm isolates recovered from the samples investigated harboured one or more resistance genes encoding resistance against various antibiotics. The antibiogram signatures of Lm isolates observed in this study is an indication that empirical treatment of listeriosis may be challenging in the future as the pathogen may obliterate the success of antibiotics. We, therefore, advocate for the recognition of the One Health approach to ensuring food safety and curbing the spread of antimicrobial resistance in food.

Hypervirulent clonal complex (CC) of Listeria monocytogenes in fresh produce from urban communities

“…Because the isolates in this study were recovered from geographically and temporally separate occasions, it remains to be tested as to their antibiotic susceptibility phenotypes as genotypes and phenotypes do not always coincide. Although antibiotic resistance in general is not a serious issue in Listeria , multidrug-resistant Listeria do occur in food ( Kayode and Okoh, 2022a , b ). Thus, it is important to monitor the prevalence of antibiotic resistance genes, especially in hypervirulence clonal groups.…”

Antibacterial and anti-biofilm activities of probiotic Lactobacillus plantarum against Listeria monocytogenes isolated from milk, chicken and pregnant women

“…In the present study, 80.8% of L. monocytogenes isolates showed the ability to form biofilm at 37°C, and of these isolates, 34.6% showed strong biofilm-forming ability. The biofilmforming potential of L. monocytogenes is influenced by the presence of virulence genes (Price et al, 2018) and antimicrobial resistance (Kayode and Okoh, 2022). MDR strains were associated with strong biofilm-forming ability, which might be attributed to the higher tolerance of these isolates to disinfectants and antimicrobials (Doulgeraki et al, 2017).…”

Molecular Characterization of Multi-Drug Resistant Fungal Isolates Obtained from Raw Cow Milk in Bowen University, Nigeria

“…Adem et al (11) also confirmed the presence of high quantities of disease-causing fungi and parasites in a large component of raw milk sourced from local animal breeders in the country. Scientific reports on multi-drug resistant bacteria are available in the country [12]. Thonda et al (13) reported the prevalence of antibiotic resistant bacteria in raw cow milk samples in Osun state, Nigeria.…”