Article Published in Microbiology Insights; SAGE

 

Genotypically confirmed Vancomycin-Resistant Staphylococcus aureus with vanB gene among clinical isolates in Kathmandu

Niranjan Nepal¹, Prakriti Mahara², Shishir Subedi³, Komal Raj Rijal¹, Prakash Ghimire¹, Megha Raj Banjara¹, Upendra Thapa Shrestha¹

¹Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu, Nepal

²GoldenGate International College, Old Baneshwor, Kathmandu, Nepal

³Grande International Hospital, Dhapasi, Kathmandu, Nepal

 

CORRESPONDING AUTHORS: Upendra Thapa Shrestha, Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu, Nepal, E-mail: upendrats@gmail.com; upendra.thapashrestha@cdmi.tu.edu.np/

Megha Raj Banjara, Central Department of Microbiology, TU Email: megha.banajara@cdmi.tu.edu.np;

 

ABSTRACT

Purpose: Methicillin-resistant Staphylococcus aureus, a common bacterial pathogen causes various infections. The acquisition of various antimicrobial-resistant genes in S. aureus has led to the transformation of this bacterium into a superbug. Vancomycin resistance among MRSA isolates is an emerging threat in empirical therapy of various infections. The study was hence aimed to find out the susceptibility status of S. aureus isolates towards vancomycin and detect mecA, vanA and vanB genes among the isolates.

Methods: A total of 1245 clinical samples from the participants attending a tertiary care hospital in Kathmandu were processed. S. aureus isolated from the samples subjected for antibiotic susceptibility pattern using the modified Kirby-Bauer disk diffusion method. Agar dilution method was used to determine the minimum inhibitory concentration of vancomycin. The antibiotic-resistant genes such as mecA, vanA, and vanB among S. aureus isolates were screened by a conventional polymerase chain reaction.

Results: Of 1245 samples, 80 S. aureus were identified. Out of which, 47.5% (38/80) were phenotypically confirmed MRSA isolates. mecA gene was detected in 84.2% (32/38) of MRSA isolates. 10.5% (4/38) were confirmed as vancomycin-intermediate S. aureus (VISA) by MIC determination. None of the isolates was positive for the vanA gene; however, two isolates were found to possess the vanB gene. The two isolates have vancomycin MIC breakpoints of 4-8 μg/mL.

Conclusion: There might be a spreading of vancomycin resistance among S. aureus, creating serious public health problems. Therefore, measures to limit vancomycin resistance should be considered in healthcare facilities as immediately as possible.

Key words: Staphylococcus aureus, Multidrug-resistant, MRSA, VISA, mecA, vanB

 

 

RECEIVED: January 23, 2023. ACCEPTED: May 26, 2023.

 

TYPE: Original Research

 

Microbiology Insights

Volume 16: 1–9

© The Author(s) 2023

Article reuse guidelines:

sagepub.com/journals-permissions

DOI: 10.1177/11786361231183675

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