Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a common and major pathogen responsible for skin and soft tissue infections (SSTIs). This study was aimed to delineate the molecular genotype distribution and antibiotic resistance genes amongst MRSA isolates from three corrections agencies in Changhua (including one prison, one jail and one rehabilitation unit) and Chang Bing Show-Chwan Memorial Hospital.
Methods: A total of 353 clinical MRSA isolates derived from custodial facilities and Chang Bing Show-Chwan Memorial Hospital in Changhua throughout the 2017 calendar year were investigated by using molecular genotyping, multi-locus sequence typing (MLST) and PCR detection for mupirocin and chlorhexidine resistance genes.
Results: Of 353 MRSA isolates, the top three leading SCCmec types in order were SCCmec IV (58.3%), SCCmec VT (28.3%), and SCCmec V (7.3%). For sequence type, ST59 was the leading type and accounted for 36.4%, followed by ST8 (35.2%) and ST45 (17.9%). With respect to MRSA derived from custodial facilities, MRSA was responsible for 78.2% of SSTI, which is significantly higher than the rate in the hospital (p <0.001). MRSA from custody predominantly carried SCCmec type IV (65.3%) and had a distribution pattern of a distinct sequence type: ST8 was the leading sequence type (38.4%), and of note, the rate of ST45 was significantly higher in comparison to the hospital (23.2% vs 9.7%, p=0.019.). For mupirocin and chlorhexidine resistance, most MRSA carried high resistant mupA genes (91.4%) but the overall qacA/B gene carriage rate was only 25.8%. By contrast, MRSA from custody had a lower rate of qacA/B gene carriage (7.8% vs 55.2%, p<0.001).
Conclusions: ST59, ST8 and ST45 MRSA are the leading circulating MRSA strains in Taiwan but the molecular distribution varied distinctly between the custodial facilities and hospital. Mupirocin resistance rate is quite high regardless of the origin of MRSA. Chlorhexidine resistance is relatively low, especially seen in MRSA from custodial facilities, and could potentially be used for custodial environmental decolonization.