Ma Mingbiao, Tao Lvyan, Li Xinyue, Liang Yanqi, Li Jue, Wang Haiping, Jiang Hongchao, Dong Jing, Han Dingrui, Du Tingyi
Department of Clinical Laboratory, Kunming Children's Hospital, Kunming, China.
Yunnan Key Laboratory of Children's Major Disease Research, Kunming Children's Hospital, Kunming, China.
Front Microbiol. 2022 Aug 11;13:944078. doi: 10.3389/fmicb.2022.944078. eCollection 2022.
Invasive () infection is associated with high rates of mortality in children. No studies have been reported on invasive infection among children in Kunming, China, and it remains unknown whether the COVID-19 epidemic has affected prevalence in this region. Thus, this study investigated the changes in molecular characteristics and antimicrobial resistance of invasive strains isolated from children in Kunming during 2019-2021. In total, 66 invasive strains isolated from children were typed by multilocus sequence typing (MLST), , and Staphylococcal cassette chromosome mec (SCC), and antimicrobial resistance and virulence genes were analyzed. A total of 19 ST types, 31 types and 3 SCC types were identified. Thirty nine (59.09%) strains were methicillin-sensitive (MSSA) and 27 (40.91%) strains were methicillin-resistant (MRSA). The most common molecular type was ST22-t309 (22.73%, 15/66), followed by ST59-t437 (13.64%, 9/66). In 2019 and 2021, the dominant molecular type was ST22-t309, while in 2020, it was ST59-t437. After 2019, the dominant molecular type of MRSA changed from ST338-t437 to ST59-t437. All strains were susceptible to tigecycline, ciprofloxacin, moxifloxacin, vancomycin, quinopudine-dafoputin, linezolid, levofloxacin, and rifampicin. From 2019 to 2021, the resistance to penicillin and sulfamethoxazole initially decreased and then increased, a trend that contrasted with the observed resistance to oxacillin, cefoxitin, erythromycin, clindamycin, and tetracycline. Sixteen antimicrobial resistance profiles were identified, with penicillin-tetracycline-erythromycin-clindamycin-oxacillin-cefoxitin being the most common, and the antimicrobial resistance profiles varied by year. The carrier rates of virulence genes, A, D, , A, B, A, B, and were 100.00%. Furthermore, , , C, R, , , , , , , and -1 had carrier rates of 96.97, 92.42, 87.88, 69.70, 84.85, 62.12, 56.06, 50, 37.87, 30.30, and 7.58%, respectively. Since COVID-19 epidemic, the annual number of invasive strains isolated from children in Kunming remained stable, but the molecular characteristics and antimicrobial resistance profiles of prevalent strains have changed significantly. Thus, COVID-19 prevention and control should be supplemented by surveillance of common clinical pathogens, particularly vigilance against the prevalence of multidrug-resistant and high-virulence strains.
侵袭性（）感染与儿童高死亡率相关。中国昆明尚无关于儿童侵袭性感染的研究报道，且新冠疫情是否影响该地区的流行情况仍不清楚。因此，本研究调查了2019 - 2021年期间从昆明儿童中分离出的侵袭性菌株的分子特征和抗菌药物耐药性变化。总共对从儿童中分离出的66株侵袭性菌株进行多位点序列分型（MLST）、分型以及葡萄球菌盒式染色体mec（SCC）分型，并分析抗菌药物耐药性和毒力基因。共鉴定出19种ST型、31种型和3种SCC型。39株（59.09%）菌株为甲氧西林敏感（MSSA），27株（40.91%）菌株为甲氧西林耐药（MRSA）。最常见的分子型为ST22 - t309（22.73%，15/66），其次是ST59 - t437（13.64%，9/66）。2019年和2021年，优势分子型为ST22 - t309，而2020年为ST59 - t437。2019年后，MRSA的优势分子型从ST338 - t437变为ST59 - t437。所有菌株对替加环素、环丙沙星、莫西沙星、万古霉素、奎奴普丁 - 达福普汀、利奈唑胺、左氧氟沙星和利福平敏感。2019年至2021年，对青霉素和磺胺甲恶唑的耐药性先下降后上升，这一趋势与观察到的对苯唑西林、头孢西丁、红霉素、克林霉素和四环素的耐药性相反。鉴定出16种抗菌药物耐药谱，其中青霉素 - 四环素 - 红霉素 - 克林霉素 - 苯唑西林 - 头孢西丁最为常见，且抗菌药物耐药谱随年份有所不同。毒力基因A、D、、A、B、A、B和的携带率为100.00%。此外，、、C、R、、、、、、、和 -1的携带率分别为96.97%、92.42%、87.88%、69.70%、84.85%、62.12%、56.06%、50%、37.87%、30.30%和7.58%。自新冠疫情以来，从昆明儿童中分离出的侵袭性菌株年度数量保持稳定，但流行菌株的分子特征和抗菌药物耐药谱发生了显著变化。因此，新冠疫情防控应辅以对常见临床病原体的监测，尤其要警惕多重耐药和高毒力菌株的流行。
