Characteristics of Erythromycin Resistance in Methicillin-Resistant Staphylococcus aureus Isolated From Raw Milk

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) strains are one of the most important multidrug resistant microorganisms that threaten human health. Objective: The present study was conducted to evaluate genotypic and phenotypic characteristics of erythromycin resistance among MRSA isolates recovered from raw milk in Iran. Materials and Methods: A total of 50 MRSA isolates were recovered from raw milk. Tests for erythromycin and clindamycin susceptibility and inducible clindamycin resistance were done. In addition, the presence of the methicillin resistance determinant (mecA), erythromycin resistance genes (ermA, ermB, ermC and msrA) and an important virulence gene (Panton– Valentine leukocidin) were investigated using polymerase chain reaction (PCR) method. Results: Forty-eight percent (24/50) and 46% (23/50) of the isolates were resistant to erythromycin and clindamycin, respectively. Seven (14%) isolates showed inducible clindamycin resistance phenotype. The mecA gene was detected in 88% (44/50) of MRSA isolates. The incidence of the ermA, ermB, ermC and msrA genes was 14%, 64%, 12%, and 26%, respectively and the PVL gene was present in 18% (9/50) of MRSA isolates. Conclusion: According to the results of the study, the incidence of erythromycin resistance genes and inducible clindamycin-resistant MRSA strains was high in raw milk samples in Iran.

Genotypic and Phenotypic Characterization of Erythromycin-Resistant Staphylococcus aureus Isolated from Bovine Mastitis and Humans in Close Contact

“…In this study, the antimicrobial susceptibility profiles of S. aureus were determined and high levels of resistance to erythromycin (52.1%) followed by clindamycin (42.8%) were detected. This resistance rate is comparable to one found by another study Mahdavi and colleagues in which they reported 48% and 46% resistance to erythromycin and clindamycin [ 30 ].…”

Species composition and methicillin resistance of staphylococci taken on dairy farms

“…У цьому контексті антибіотикостійкі бактерії у тварин, яких використовують для одержання харчових продуктів, являють собою серйозну загрозу як потенційне джерело інфекцій людини (Horiuk, 2018;Abreu et al, 2019;Medina et al, 2020). Такий зооноз може відбуватися як через прямий контакт з тваринами, так і у процесі виробництва і споживання продуктів тваринного походження (Kukhtyn et al, 2017;Mahdavi et al, 2019;Rahi et al, 2020). Стурбованість викликає не тільки потенційна передача самих резистентних мікроорганізмів, але і горизонтальна передача генів детермінант стійкості від мікрофлори тварини до патогенів людини Alnakip et al, 2019).…”