Occurrence, molecular confirmation, and multidrug resistance of methicillin-resistant Staphylococcus aureus and Staphylococcus pseudintermedius in companion animals in Indonesia

Vet World Vol.19 January-2026 Article - 23

Research Article

Veterinary World, 19(1): 324-311

https://doi.org/10.14202/vetworld.2026.324-311

Ghias Ghifari Alhadz¹, Siti Isrina Oktavia Salasia¹, Fajar Budi Lestari², Alyaa Rifqoh Putri Yosyana¹, Madarina Wasissa¹, Yasinta Rahma Setianingrum¹, and Rini Widayanti³

1. Department of Clinical Pathology, Faculty of Veterinary Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.

2. Department of Bioresources Technology and Veterinary, Vocational College, Universitas Gadjah Mada, Yogyakarta, Indonesia.

3. Department of Biochemistry, Faculty of Veterinary Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.

Background and Aim: Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP) are increasingly recognized as important pathogens in companion animals, with significant zoonotic and public health implications. Data on methicillin-resistant staphylococci in pets in Indonesia remain scarce, particularly from clinical settings. This study aimed to determine the occurrence, molecular identity, and antimicrobial resistance (AMR) profiles of MRSA and MRSP isolated from companion animals presenting with clinical infections using an integrated phenotypic and genotypic diagnostic approach.

Materials and Methods: We collected 100 clinical swab samples from dogs (n = 26), cats (n = 67), and rabbits (n = 7) presenting with signs of bacterial infection at veterinary clinics in Central Java and the Special Region of Yogyakarta, Indonesia. Isolates were identified using standard biochemical tests and confirmed molecularly by PCR targeting the 23S rRNA and nuc genes for S. aureus and PCR–restriction fragment length polymorphismof the pta gene for S. pseudintermedius. Methicillin resistance was screened using oxacillin resistance screening agar base, phenotypically confirmed by disk diffusion (cefoxitin or oxacillin), and genotypically verified by detection of the mecA gene. The Kirby–Bauer method was used to perform antimicrobial susceptibility testing against 11 commonly used antibiotics.

Results: Of the 100 samples, 41 S. aureus and 14 S. pseudintermedius isolates were confirmed. Based on mecA detection, 27/41 (65.9%) S. aureus isolates were classified as MRSA and 13/14 (92.9%) S. pseudintermedius isolates were classified as MRSP. MDR was highly prevalent, observed in 92.6% of MRSA and 92.3% of MRSP isolates. High resistance rates were noted against β-lactam antibiotics, including penicillin, ampicillin, and amoxicillin. Several isolates carried mecA despite being phenotypically susceptible, indicating silent or low-expression resistance determinants.

Conclusion: This study reveals a great burden of methicillin- and multidrug-resistant staphylococci among companion animals with clinical infections in Indonesia. The detection of mecA-positive MRSA and MRSP underscores a substantial zoonotic risk and highlights the limitations of phenotypic methods. These findings emphasize the need for routine molecular diagnostics, strengthened antimicrobial stewardship in veterinary practice, and integrated One Health surveillance to mitigate the spread of AMR across animal–human interfaces.

Keywords: Antimicrobial resistance, companion animals, Indonesia, mecA gene, methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus pseudintermedius, multidrug resistance, One Health.

How to cite this article: Alhadz GG, Salasia SIO, Lestari FB, Yosyana ARP, Wasissa M, Setianingrum YR, Widayanti R. Occurrence, molecular confirmation, and multidrug resistance of methicillin-resistant Staphylococcus aureus and Staphylococcus pseudintermedius from clinical infections in companion animals in Indonesia. Vet World. 2026;19(1):324–311.

Received: 11-10-2025 Accepted: 23-12-2025 Published online: 25-01-2026

Corresponding author: Siti Isrina Oktavia Salasia E-mail: isrinasalasia@ugm.ac.id

DOI: 10.14202/vetworld.2026.324-311

Copyright: Alhadz, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.