Prevalence and antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus clones: A study at Taksin Hospital, Bangkok, Thailand

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen in human diseases. Thirtyseven clinical clones from different patients were tested for a molecular study of the mecA gene and multilocus sequence types (ST). Total genomic extraction, followed by a polymerase chain reaction (PCR) for DNA amplification with specific primers for mecA, and specific primers for various ST were used. Molecular typing for the study of genetic relationships among clones was performed by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Antimicrobial susceptibility testing for all clones to 9 drugs was performed by the disk diffusion and vancomycin Etest. The presence of mecA was detected in all clones. The most common ST was MRSA-ST30, accounting for 81.1% of all MRSA tested, followed by MRSA-ST8/ST97/ST779 (8.1%), MRSA-ST239 (2.7%) and MRSA-nontypeable clones (8.1%). Molecular typing by ERIC-PCR demonstrated DNA fingerprints with corresponding results with sequence types. All clones were susceptible (70-100%) to fosfomycin, fusidic acid, gentamicin, tetracycline, trimethoprimsulfamethoxazole and vancomycin [minimal inhibitory concentration (MIC) range, MIC 50 and MIC 90 were 0.25-1.0, 0.5 and 0.75 µg/ml, respectively by using E-test] but resistant to ciprofloxacin, clindamycin and erythromycin. Inducible macrolide, lincosamide-type B streptogramin resistance (iMLSB) phenotype was 5.4% while constitutive MLSB phenotype was 91.9%. For MRSA-ST30 clones, 96.7% were multi-drug resistant (MDR) with the most common pattern being resistant to ciprofloxacin, clindamycin and erythromycin. These results suggest the importance of MRSA in the field of epidemiology at a hospital in Thailand.

The Prevalence, Epidemiological, and Molecular Characterization of Methicillin-Resistant Staphylococcus aureus (MRSA) in Macau (2017–2022)

“…Studies have demonstrated that, compared to methicillin-susceptible Staphylococcus aureus (MSSA), MRSA exhibits higher morbidity, mortality rates, and incurs elevated healthcare costs, posing a significant threat to global public health [ 5 , 6 , 7 ]. According to reports, in many Asian countries, the prevalence of MRSA in hospitals can reach as high as 50–60% [ 8 , 9 ]. In China, despite a recent decline in MRSA incidence, monitoring reports indicate an ongoing prevalence of over 30% annually [ 10 ].…”

Study of Streptococcus pneumoniae serotype 19A blood isolates from Thailand by enterobacterial repetitive intergenic consensus (ERIC)-PCR typing

“…ERIC-PCR is a simple, sharp, and costeffective genotyping technology that discriminates different types of bacterial isolates. The widespread distribution of these repetitive DNA elements of various bacteria should enable the rapid identification of bacterial species and isolates [12][13][14][15], which is useful for the analysis of bacterial genomes [16][17][18][19]. The ERIC sequences can be utilized as efficient primer binding sites in a PCR to produce fingerprints of different bacterial genomes [20][21][22].…”