2015—2021年CHINET伤口脓液临床分离菌的分布及耐药性变迁

Changing distribution and antimicrobial resistance profiles of clinical isolates from wound pus:results from the CHINET Antimicrobial Resistance Surveillance Program,2015-2021

目的了解2015—2021年CHINET细菌耐药监测网中伤口脓液临床分离菌的分布及耐药性。方法对CHINET细菌耐药监测网2015—2021年所有伤口脓液标本按照常规方法进行细菌分离、培养和鉴定。采用纸片扩散法或商品化药敏试验自动测定仪按CHINET统一技术方案进行抗菌药物敏感性试验。按2021年CLSI折点标准判断结果。结果从2015—2021年伤口脓液标本分离细菌90856株,其中革兰阳性菌占36.0%(32729株),革兰阴性菌64.0%(58127株)。最常见的分离菌株为大肠埃希菌、金黄色葡萄球菌、肺炎克雷伯菌、铜绿假单胞菌和肠球菌属等。脓液标本中88.9%的菌株分离自住院患者,11.1%的菌株分离自门诊患者。90856株伤口脓液标本分离株的7年平均科室分布为外科(53.4±3.6)%(共49191株)和内科(9.6±1.0)%(共8960株)。大肠埃希菌对碳青霉烯类抗生素的耐药率低(1.1%)。产ESBL大肠埃希菌的检出率为51.1%;大肠埃希菌对头孢噻肟、环丙沙星和甲氧苄啶-磺胺甲唑的耐药率>35%。产ESBL肺炎克雷伯菌的检出率为29.7%,肺炎克雷伯菌对亚胺培南和美罗培南的耐药率从2015年至2021年的耐药率呈波动性变化,均在2020年达最高耐药率,分别为12.5%和12.7%;但其他肠杆菌目细菌对碳青霉烯类耐药率低(产酸克雷伯菌和奇异变形杆菌产ESBL检出率为18.3%和32.5%)。此外,铜绿假单胞菌对亚胺培南和美罗培南的耐药率分别为13.1%和10.6%;但鲍曼不动杆菌显示对上述两药的耐药率高,分别为71.1%和72.4%。7年中伤口脓液标本中的MRSA检出率为22.7%。粪肠球菌中检出3株万古霉素耐药菌株和122株利奈唑胺耐药菌株。屎肠球菌中检出万古霉素耐药菌株31株和利奈唑胺耐药11株。结论临床脓液标本临床分离菌中MRSA、万古霉素耐药肠球菌、利奈唑胺耐药肠球菌、肠杆菌目细菌中产ESBL菌、碳青霉烯类耐药菌近年来的检出率显示低于当年全国CHINET总体监测细菌的检出率,提示分离自不同种类标本的临床菌株对抗菌药物的耐药率是不一样的。在加强细菌耐药性监测的同时,亦应加强感染部位临床菌株的耐药性监测。

Objective To investigate the distribution and antimicrobial resistance profiles of the clinical isolates from wound pus in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods All the bacterial strains were isolated from wound pus samples from 2015 to 2021.The isolates were identified according to conventional methods.Antimicrobial susceptibility test was conducted by disk diffusion method or commercial automated susceptibility testing systems according to CHINET-specified uniform protocol.The results are interpreted according to the Clinical and Laboratory Standards Institute(CLSI)breakpoints(2021 Edition).Results A total of 90856 bacterial strains were isolated from wound pus samples from 2015 to 2021,of which gram positive bacteria accounted for 36.0%(32729/90856)and gram negative bacteria accounted for 64.0%(58127/90856).The most common bacterial species were Escherichia coli,Staphylococcus aureus,Klebsiella pneumoniae,Pseudomonas aeruginosa,and Enterococcus.About 88.9%of these strains were isolated from inpatients and 11.1%from outpatients.The strains collected from surgery department and internal medicine accounted for(53.4±3.6)%(49191/90856)and(9.6±1.0)%(8960/90856)on average over the 7-year period.E.coli showed low level resistance to carbapenems(1.1%).The prevalence of ESBLs-producing E.coli was 51.1%.More than 35%of the E.coli isolates were resistant to cefotaxime,ciprofloxacin,and trimethoprim-sulfamethoxazole.The prevalence of ESBLs-producing K.pneumoniae was 29.7%.The prevalence of imipenem-resistant and meropenem-resistant K.pneumoniae varied from 2015 to 2021,but reached the peak level(12.5%and 12.7%)in 2020.However,other Enterobacterales species showed low resistance rates to carbapenems.The prevalence of ESBLs-producing Klebsiella oxytoca and Proteus was 18.3%and 32.5%,respectively.About 13.1%and 10.6%of P.aeruginosa isolates were resistant to imipenem and meropenem,respectively.However,71.1%and 72.4%of A.baumannii isolates were resistant to imipenem and meropenem,respectively.The overall prevalence of MRSA was 22.7%in wound pus samples over the 7-year period.Three vancomycin-resistant strains and 122 linezolid-resistant isolates were identified in Enterococcus faecalis.Thirty-one vancomycin-resistant strains and 11 linezolid-resistant strains were detected in Enterococcus faecium.Conclusions The overall prevalence of MRSA,vancomycin-resistant Enterococcus(VRE),linezolid-resistant Enterococcus(LRE),ESBLs-producing Enterobacterales,and carbapenem-resistant organisms(CRO)in the isolates from wound pus samples was relatively lower than the corresponding prevalence in the total clinical isolates collected in the CHINET program.This finding suggests that the antimicrobial resistance profile of bacterial isolates may vary with the source of clinical samples.Therefore,we should strengthen the antimicrobial resistance surveillance for the isolates from different sites of infection.