Tet(M) Mediates Tetracycline Resistance in Methicillin-Resistant Staphylococcus aureus (MRSA) Clinical Isolates from the Private Hospital Sector in KwaZulu-Natal (KZN), South Africa

To elucidate the molecular determinants of tetracycline resistance in clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates from the private health sector in KwaZulu-Natal province (KZN), South Africa (SA). Seventy-five clinical MRSA isolates were collected from the private hospital sector in KZN, SA over a one-year period. Susceptibility to antibiotics (tetracycline, doxycycline, minocycline and tigecycline) were determined and tetracycline resistant strains were screened using polymerase chain reaction (PCR) for the presence of four putative tetracycline resistance determinants (tet(K), tet(L), tet(M) and tet(O)). Efflux inhibitors were used to assess the possibility of efflux-mediated resistance.All isolates were mecA gene positive and susceptible to doxycycline, minocycline and tigecycline. Of note, 47 (62.67%) isolates were resistant to tetracycline. Doxycycline exhibited the largest number of intermediate resistance 20 (26.67%) in all the isolates. The tet(M)gene was found in all 47tetracycline-resistant isolates. No tet(L), tet(K) and tet(O) were detected. Efflux inhibitors did not have any significant effect on the sensitivity of tetracycline-resistant isolates suggesting that efflux played a minor role in tetracycline resistance. In conclusion; Tet(M) mainly mediates tetracycline resistance in MRSA in the private health sector in KZN, SA. This report on the prevalence and molecular determinants of tetracycline resistance is the first study on clinical MRSA isolates from the private health sector in SA

Emergence and Spread of Extended Spectrum β-Lactamase Producing Enterobacteriaceae (ESBL-PE) in Pigs and Exposed Workers: A Multicentre Comparative Study between Cameroon and South Africa

Extended spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) represent a significant public health concern globally and are recognized by the World Health Organization as pathogens of critical priority. However, the prevalence of ESBL-PE in food animals and humans across the farm-to-plate continuum is yet to be elucidated in Sub-Saharan countries including Cameroon and South Africa. This work sought to determine the risk factors, carriage, antimicrobial resistance profiles and genetic relatedness of extended spectrum β-lactamase producing Enterobacteriaceae (ESBL-PE) amid pigs and abattoir workers in Cameroon and South Africa. ESBL-PE from pooled samples of 432 pigs and nasal and hand swabs of 82 humans were confirmed with VITEK 2 system. Genomic fingerprinting was performed by ERIC-PCR. Logistic regression (univariate and multivariate) analyses were carried out to identify risk factors for human ESBL-PE carriage using a questionnaire survey amongst abattoir workers. ESBL-PE prevalence in animal samples from Cameroon were higher than for South Africa and ESBL-PE carriage was observed in Cameroonian workers only. Nasal ESBL-PE colonization was statistically significantly associated with hand ESBL-PE (21.95% vs. 91.67%; p = 0.000; OR = 39.11; 95% CI 2.02–755.72; p = 0.015). Low level of education, lesser monthly income, previous hospitalization, recent antibiotic use, inadequate handwashing, lack of training and contact with poultry were the risk factors identified. The study highlights the threat posed by ESBL-PE in the food chain and recommends the implementation of effective strategies for antibiotic resistance containment in both countries