Detection of Clindamycin Resistance Antibiotic Genes among Staphylococcus Isolates by Using Real Time PCR

Mahmoud, Alzahraa Nasser; Yousef, Laila Mohamed; Mohammed, Ashraf K; Sayed, Sherif A.

doi:10.21608/smj.2025.419505.1612

Detection of Clindamycin Resistance Antibiotic Genes among Staphylococcus Isolates by Using Real Time PCR

Document Type : Review Article

Authors

¹ Clinical pathology department, faculty of medicine, sohag university, Egypt

² Clinical pathology department, faculty of medicine, sohag university

³ Department of Clinical Pathology, Faculty of Medicine, Sohag University.

⁴ Clinical&chemical pathology department faculty of medicine Sohag university

10.21608/smj.2025.419505.1612

Abstract

Background: S. aureus is a prevalent person pathogen, accountable for a broad range of community- and hospital-acquired illnesses. The rise of methicillin-resistant Staphylococcus aureus (MRSA) and resistance to macrolide-lincosamide-streptogramin B (MLSB) medicines, especially clindamycin, presents significant therapeutic difficulties. This study aimed to determine the occurrence of constitutive and inducible clindamycin resistance among S. aureus clinical isolates utilizing real-time PCR for observation of resistance genes. Among the isolates, inducible clindamycin resistance (iMLSB) has been observed in 23.4%, with a markedly higher prevalence in MRSA (76.4%) compared to MSSA. Constitutive resistance (cMLSB) was lower, at 7.1% in MRSA and 5.8% in MSSA. Molecular analysis revealed the presence of ermA (15.62%), ermB (3.12%), and ermC (18.75%) genes, with higher prevalence of these genes in inducible clindamycin-resistant MRSA isolates. These results highlight the increasing burden of MLSB resistance and emphasize the necessity of routine D-testing and molecular surveillance to guide effective treatment and prevent therapeutic failure.

Conclusion: This study demonstrates a significant occurrence of inducible clindamycin resistance among Staphylococcus aureus isolates, particularly MRSA, with a strong association to erm genes. The high rate of iMLSB resistance underscores the risk of treatment failure if clindamycin is prescribed without prior D-testing. Moreover, the molecular detection of erm genes confirms their critical role in mediating resistance and indicates the importance of integrating genetic surveillance into diagnostic protocols. Strengthening antimicrobial stewardship, promoting rational antibiotic use, and applying reliable diagnostic methods are essential strategies to limit the spread of resistant S. aureus strains and improve patient outcomes.

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