2026_Antimicrobial Resistance and Genetic Characterisation Of Staphylococcus Aureus Clinical Isolates from Terengganu, Malaysia
| Format: | General Document |
|---|
| _version_ | 1860798364233236480 |
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| building | INTELEK Repository |
| collection | Online Access |
| collectionurl | https://intelek.unisza.edu.my/intelek/pages/search.php?search=!collection8803 |
| copyright | Copyright©PWB2026 |
| country | Malaysia |
| date | 2025-07-11 |
| format | General Document |
| id | 17473 |
| institution | UniSZA |
| originalfilename | ANTIMICROBIAL RESISTANCE AND GENETIC CHARACTERISATION OF Staphylococcus aureus CLINICAL ISOLATES FROM TERENGGANU, MALAYSIA (PHD_2025).pdf |
| person | Ainal Mardziah Che Hamzah |
| recordtype | oai_dc |
| resourceurl | https://intelek.unisza.edu.my/intelek/pages/view.php?ref=17473 |
| sourcemedia | Server storage Scanned document |
| spelling | 17473 https://intelek.unisza.edu.my/intelek/pages/view.php?ref=17473 https://intelek.unisza.edu.my/intelek/pages/search.php?search=!collection8803 General Document Malaysia Library Staff (Top Management) Library Staff (Management) Library Staff (Support) Terengganu Faculty of Health Sciences English application/pdf 1.6 Public Access Server storage Scanned document Universiti Sultan Zainal Abidin Universiti Sultan Zainal Abidin 191 Dissertations, Academic Methicillin-Resistant Staphylococcus Aureus (MRSA) Staphylococcus Aureus Antimicrobial Resistance Whole Genome Sequencing (WGS) Copyright©PWB2026 Thesis 2025-07-11 Ainal Mardziah Che Hamzah Multidrug-resistant (MDR) Bacteria SCCmec Typing Virulence Genes MLSB Resistance Phenotype Molecular Epidemiology Terengganu, Malaysia Staphylococcus Aureus Drug Resistance in Microorganisms Molecular Epidemiology Anti-infective Agents 2026_Antimicrobial Resistance and Genetic Characterisation Of Staphylococcus Aureus Clinical Isolates from Terengganu, Malaysia Staphylococcus aureus presents a significant challenge to healthcare systems worldwide due to its diverse resistance mechanisms, which have led to the emergence of multidrug-resistant (MDR) strains such as methicillin-resistant S. aureus (MRSA). Beyond its potential for MDR, S. aureus also harbours various virulence factors that further amplify its pathogenic potential. This study aimed to comprehensively characterise clinical S. aureus isolates through antibiotic resistance profiling and genotypic characterisation. Additionally, whole genome sequencing (WGS) was also performed on a selection of MDR-MRSA isolates. A total of 197 non-repetitive MRSA isolates were collected from Hospital Sultanah Nur Zahirah (HSNZ) between July 2016 and December 2020, and 109 methicillin-susceptible S. aureus (MSSA) isolates were collected between July 2016 and June 2017. Antibiotic susceptibility of MRSA isolates against 24 antibiotics from 16 antimicrobial classes, including macrolide-lincosamide-streptogramin B (MLSB) resistance phenotypes, was assessed. The carriage of staphylococcal cassette chromosome mec (SCCmec) types among MRSA isolates, as well as the presence of MLSB resistance genes and 19 types of exotoxin virulence genes in both MRSA and MSSA isolates, were screened. A total of 88 MDR-MRSA isolates underwent WGS using a short-read, paired-end sequencing strategy. The MRSA isolates were predominantly hospital-acquired (76.1%, 150/197) and showed a higher prevalence among male patients (57.9%, 114/197, p = 0.027) and individuals aged 45–64 years (33.5%, 66/197, p = 0.000). Pus specimens were the most common source of isolation, accounting for 54.8% (108/197) of isolates. Antibiotic susceptibility testing revealed that most of the MRSA isolates were MDR (74.1%, 146/197), with high resistance rates against beta-lactams and fluoroquinolones. Additionally, approximately half of the isolates exhibited the inducible MLSB (iMLSB) resistance phenotype (52.3%, 103/197). The majority of the MRSA isolates belonged to SCCmec type IV (78.7%, 155/197) and had a high carriage rate of the MLSB resistance gene ermC (91.1%, 113/124). Two of the five MLSB-resistant MSSA isolates also carried the ermC gene. Virulence profiling indicated that the haemolysin genes hla and hld were common in both MRSA and MSSA isolates, with prevalence rates > 78%, while the enterotoxin gene cluster (EGC) was detected in over half of the MRSA isolates. Molecular typing from WGS data revealed ST22-SCCmec IV as the dominant clone (69.3%, 61/88). Notably, two novel sequence types (STs) were also identified (ST7879 and ST7883), and the emergence of ST672 in this study was reported for the first time in Malaysia, highlighting the dynamic clonal population of the HSNZ MRSA isolates. This study also demonstrated a high concordance between phenotypic resistance and genotypic predictions from WGS data, with > 95% concordance rates recorded for most antibiotics. The high prevalence of MDR strains and the dominance of the iMLSB phenotype among the MRSA isolates, coupled with the carriage of multiple virulence genes in both the MRSA and MSSA isolates, underscore an ongoing public health threat. The emergence of novel STs such as ST7879 and ST7883, along with the first report of ST672 strains, stresses the need for ongoing surveillance and strict infection control. uuid:e2d2cd39-9186-4739-a50d-bec7635e6e61 Adobe PDF Library 22.2.244 ANTIMICROBIAL RESISTANCE AND GENETIC CHARACTERISATION OF Staphylococcus aureus CLINICAL ISOLATES FROM TERENGGANU, MALAYSIA (PHD_2025).pdf |
| spellingShingle | 2026_Antimicrobial Resistance and Genetic Characterisation Of Staphylococcus Aureus Clinical Isolates from Terengganu, Malaysia |
| state | Terengganu |
| subject | Dissertations, Academic Staphylococcus Aureus Drug Resistance in Microorganisms Molecular Epidemiology Anti-infective Agents |
| summary | Staphylococcus aureus presents a significant challenge to healthcare systems worldwide due to its diverse resistance mechanisms, which have led to the emergence of multidrug-resistant (MDR) strains such as methicillin-resistant S. aureus (MRSA). Beyond its potential for MDR, S. aureus also harbours various virulence factors that further amplify its pathogenic potential. This study aimed to comprehensively characterise clinical S. aureus isolates through antibiotic resistance profiling and genotypic characterisation. Additionally, whole genome sequencing (WGS) was also performed on a selection of MDR-MRSA isolates. A total of 197 non-repetitive MRSA isolates were collected from Hospital Sultanah Nur Zahirah (HSNZ) between July 2016 and December 2020, and 109 methicillin-susceptible S. aureus (MSSA) isolates were collected between July 2016 and June 2017. Antibiotic susceptibility of MRSA isolates against 24 antibiotics from 16 antimicrobial classes, including macrolide-lincosamide-streptogramin B (MLSB) resistance phenotypes, was assessed. The carriage of staphylococcal cassette chromosome mec (SCCmec) types among MRSA isolates, as well as the presence of MLSB resistance genes and 19 types of exotoxin virulence genes in both MRSA and MSSA isolates, were screened. A total of 88 MDR-MRSA isolates underwent WGS using a short-read, paired-end sequencing strategy. The MRSA isolates were predominantly hospital-acquired (76.1%, 150/197) and showed a higher prevalence among male patients (57.9%, 114/197, p = 0.027) and individuals aged 45–64 years (33.5%, 66/197, p = 0.000). Pus specimens were the most common source of isolation, accounting for 54.8% (108/197) of isolates. Antibiotic susceptibility testing revealed that most of the MRSA isolates were MDR (74.1%, 146/197), with high resistance rates against beta-lactams and fluoroquinolones. Additionally, approximately half of the isolates exhibited the inducible MLSB (iMLSB) resistance phenotype (52.3%, 103/197). The majority of the MRSA isolates belonged to SCCmec type IV (78.7%, 155/197) and had a high carriage rate of the MLSB resistance gene ermC (91.1%, 113/124). Two of the five MLSB-resistant MSSA isolates also carried the ermC gene. Virulence profiling indicated that the haemolysin genes hla and hld were common in both MRSA and MSSA isolates, with prevalence rates > 78%, while the enterotoxin gene cluster (EGC) was detected in over half of the MRSA isolates. Molecular typing from WGS data revealed ST22-SCCmec IV as the dominant clone (69.3%, 61/88). Notably, two novel sequence types (STs) were also identified (ST7879 and ST7883), and the emergence of ST672 in this study was reported for the first time in Malaysia, highlighting the dynamic clonal population of the HSNZ MRSA isolates. This study also demonstrated a high concordance between phenotypic resistance and genotypic predictions from WGS data, with > 95% concordance rates recorded for most antibiotics. The high prevalence of MDR strains and the dominance of the iMLSB phenotype among the MRSA isolates, coupled with the carriage of multiple virulence genes in both the MRSA and MSSA isolates, underscore an ongoing public health threat. The emergence of novel STs such as ST7879 and ST7883, along with the first report of ST672 strains, stresses the need for ongoing surveillance and strict infection control. |
| title | 2026_Antimicrobial Resistance and Genetic Characterisation Of Staphylococcus Aureus Clinical Isolates from Terengganu, Malaysia |
| title_full | 2026_Antimicrobial Resistance and Genetic Characterisation Of Staphylococcus Aureus Clinical Isolates from Terengganu, Malaysia |
| title_fullStr | 2026_Antimicrobial Resistance and Genetic Characterisation Of Staphylococcus Aureus Clinical Isolates from Terengganu, Malaysia |
| title_full_unstemmed | 2026_Antimicrobial Resistance and Genetic Characterisation Of Staphylococcus Aureus Clinical Isolates from Terengganu, Malaysia |
| title_short | 2026_Antimicrobial Resistance and Genetic Characterisation Of Staphylococcus Aureus Clinical Isolates from Terengganu, Malaysia |
| title_sort | 2026_antimicrobial resistance and genetic characterisation of staphylococcus aureus clinical isolates from terengganu, malaysia |