Hong Xiaolan, Zhou Shaobo, Dai Xubo, Xie Dandan, Cai Yuanyuan, Zhao Guimei, Li Bin
Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fujian, China.
Department of Clinical Laboratory, The 910 Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Fujian, China.
Front Microbiol. 2023 Sep 20;14:1236497. doi: 10.3389/fmicb.2023.1236497. eCollection 2023.
() is the most common causative agent of burn wound infection, that often leads to high morbidity and mortality. However, there is not enough knowledge about the molecular epidemiology and antimicrobial susceptibility of isolates from burn wound infections in Fujian, China.
Between 2016 and 2021, 90 isolates were collected from burn wound infections in Fujian, China, including 59 methicillin-resistant (MRSA) strains and 31 methicillin-susceptible (MSSA) strains. These were investigated for molecular characteristics, virulence genes, biofilms, and antimicrobial susceptibility. All the isolates were genotyped by multilocus sequence typing (MLST), typing, typing, and SCC typing. Conventional PCR was performed for the detection of virulence genes. Biofilm formation capacity was assessed by tissue culture plate assay (TCP). The antimicrobial susceptibility of the isolates was evaluated using the dilution method.
In total, 37 sequence types (ST) and 34 Staphylococcal protein A () types (including a new type named -t20720) were identified based on multilocus sequence typing (MLST) and typing, respectively. CC8-ST239-t030-I-SCCIII (57.6%,34/59) and CC7-ST7-t091-I (16.1%, 5/31) represented the main clone of MRSA and MSSA isolates, respectively. Antibiotic susceptibility testing identified a significant difference in resistance rates between ST239 and non-ST239 isolates ( < 0.05). Twelve virulence genes were detected, of which the most common were and (both 100%), followed by and (both 96.7%), (95.6%), (81.1%), (62.2%), (50%), (26.7%), and (4.4%). Moreover, , , I, and III were significantly correlated with burn severity ( < 0.05). MRSA isolates were less likely, compared with MSSA isolates, to carry , and ( < 0.05). A new spa type, t20720, was identified that contains , , , , , , , and genes and has strong biofilm formation ability.
CC8-ST239-t030-I-SCCIII and CC7-ST-7-t091-I were the prevalent molecular signatures of MRSA and MSSA isolates from burn wound infections in Fujian, China, respectively. The newly identified -t20720 isolate, which carries a wide range of virulence genes and has strong biofilm formation ability, requires special clinical attention.
（某菌）是烧伤创面感染最常见的病原体，常导致高发病率和死亡率。然而，关于中国福建烧伤创面感染分离株的分子流行病学和抗菌药物敏感性，目前了解不足。
2016年至2021年期间，从中国福建的烧伤创面感染中收集了90株分离株，其中包括59株耐甲氧西林金黄色葡萄球菌（MRSA）菌株和31株甲氧西林敏感金黄色葡萄球菌（MSSA）菌株。对这些菌株进行了分子特征、毒力基因、生物膜和抗菌药物敏感性研究。所有分离株均通过多位点序列分型（MLST）、spa分型、SCC分型进行基因分型。采用常规PCR检测毒力基因。通过组织培养板试验（TCP）评估生物膜形成能力。采用稀释法评估分离株的抗菌药物敏感性。
基于多位点序列分型（MLST）和spa分型，分别鉴定出37种序列类型（ST）和34种葡萄球菌蛋白A（spa）类型（包括一种名为t20720的新类型）。CC8-ST239-t030-I-SCCIII（57.6%，34/59）和CC7-ST7-t091-I（16.1%，5/31）分别代表MRSA和MSSA分离株的主要克隆型。药敏试验显示，ST239和非ST239分离株的耐药率存在显著差异（P<0.05）。检测到12种毒力基因，其中最常见的是mecA和spa（均为100%），其次是sasX和sasY（均为96.7%）、scn（95.6%）、eta（81.1%）、lukS-PV（62.2%）、hla（50%）、hlb（26.7%）和lukF-PV（4.4%）。此外，eta、hla、I和III与烧伤严重程度显著相关（P<0.05）。与MSSA分离株相比，MRSA分离株携带sasX、sasY和lukF-PV的可能性较小（P<0.05）。鉴定出一种新的spa类型t20720，其含有sasX、sasY、scn、eta、lukS-PV、lukF-PV、hla、hlb和mecA基因，且具有较强的生物膜形成能力。
CC8-ST239-t030-I-SCCIII和CC7-ST-7-t091-I分别是中国福建烧伤创面感染MRSA和MSSA分离株的主要分子特征。新鉴定的t20720分离株携带多种毒力基因且具有较强的生物膜形成能力，需要临床特别关注。
