Ph.D.
Nguyen Thi Le Thuy
Deputy head of Department of Animal Biotechnology - Biotechnology Center of Ho Chi Minh City
Title: Distribution and characteristics of methicillin-resistant staphylococci from non-clinical environments in southern Vietnam
Yuri Ushijima1, Le Thuy Thi Nguyen2, Annisa Krama1, Momoko Matsuoka3, Kenta Yamazaki4,
Terumi Miyata5, Masato Higashide5, Nghi Bao Nguyen3,6, Mais Maree1 and Kazuya Morikawa1
- Institute of Medicine, University of Tsukuba, Japan
- Biotechnology Center of Ho Chi Minh City, Vietnam
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan
- College of Medical Sciences, School of Medicine and Health Sciences, University of Tsukuba, Japan
- Kotobiken Medical Laboratories, Inc., Tsukuba, Japan
- Center for Molecular Biomedicine, University of Medicine and Pharmacy at HCMC, Ho Chi Minh City, Vietnam
Background: Methicillin-resistance in pathogenic staphylococci such as Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE) represents a major global health concern. Acquisition of methicillin-resistant (mec) genes enables these organisms to evade Ī²-lactam antibiotics and has facilitated their spread beyond hospitals to the wider community and environment. Nonpathogenic Methicillin-resistant staphylococci (MRS), which inhabit various environments, are considered potential reservoirs of mec genes. However, information on MRS in non-clinical settings remains limited.
Methods: This study conducted a survey on MRS in Vietnam between 2022 and 2024, targeting five categories: meats, livestock, animal-feces, environments, and pets. MRS isolates were obtained using Mannitol-Salt agar containing cefoxitin (CFX) and the presence of resistance genes (mecA, mecB, mecC, mecD) and SCCmec types were confirmed by polymerase chain reaction (PCR). Species identification were performed by TOF-MS for all isolates. Methicillin resistance phenotypes were determined by disk diffusion test using oxacillin (MPI) and cefoxitin (CFX).
Results: A total of 167 MRS were isolated from 183 swabs. The isolates comprised 19 species and 7 SCCmec types. The detection rate of MRS was highest in meats (89.3%), followed by livestock (65.3%), animal feces (58.8%), environments (53.6%), and pets (31.6%). Species commonly colonized in humans were detected at higher rates in meats and pets. In disk diffusion test, inhibition zone diameters for MPI and CFX were correlated among the MRS carrying hospital-acquired SCCmec types (I, II and III), but not among those carrying other types. Isolates showing a faint mecAPCR signal intensity tended to exhibit lower resistance. Heterogeneous resistance, characterized by colonies within inhibitory CFX zones, was observed in 11 species with the highest frequency in Staphylococcus sciuri (43.8%).
Conclusions: This study identified the species, SCCmec types, and the MPI and CFX susceptibilities of MRS isolates from non-clinical settings in Vietnam. The high detection rate indicates the widespread dissemination of diverse MRS in the environment. A correlation between MPI and CFX inhibitory zone diameters was observed only among isolates carrying certain SCCmec types.
Biography of the presenting author
Le Thuy Thi Nguyen completed her PhD at the age of 34 years from University of Tsukuba, Japan. She now is the Deputy head of Department of Animal Biotechnology – Biotechnology Center of Ho Chi Minh City, Vietnam. Her research interests are: (1) Molecular microbiology and epidemiology of antimicrobial resistance in major pathogens including Gram-positive and Gram-negative bacteria; (2) Molecular diagnosis of human and animal pathogens; (3) Development of recombinant proteins for prevention and therapy; (4) Preclinical trial in animal models. She has published more than 20 papers in reputed journals.
Presenting author details
Full name: Le Thuy Thi Nguyen
Contact number: (+84) 0983397430
Email: ntlthuy.shtp@tphcm.gov.vn
Website: https://www.hcmbiotech.com.vn/en/
Session name: Antimicrobial resistance and treatmentĀ Category: Oral presentation