Invasive pulmonary fungal diseases (IPFD) continue to posing an increasing clinical and public health burden on immunocompromised populations. In many Asian settings, the diagnosis of IPFD faces substantial challenges driven by the high prevalence of comorbidities, including poorly controlled diabetes, tuberculosis (TB), and human immunodeficiency virus (HIV) infection, considerable heterogeneity in local pathogens, and disparities in access to diagnostic resources. To address these unmet needs, experts from 18 countries collaboratively developed this consensus, which provides a diagnostic algorithm tailored to high-burden Asian settings based on existing international and regional guidelines. When clinical manifestations are atypical or diagnostic clues are limited, the algorithm prioritizes evaluation for common and regionally prevalent IPFD, followed by stepwise expansion to other potential fungal pathogens. In addition, this consensus outlines the regional accessibility of different diagnostic modalities across Asia. This consensus focuses exclusively on optimization of the diagnostic algorithm and does not provide specific recommendations regarding antifungal therapy. Notably, improved diagnosis of IPFD through this algorithm may contribute to better patient outcomes and strengthened public health strategies in high-burden regions.

BACKGROUND:Staphylococcus aureus is one of the most important bacteria in human colonization and infection. Clonal complex1 (CC1) is one of the largest and most important S. aureus CCs, and it is a predominant clone in S. aureus colonization and can cause a series of S. aureus infections including bloodstream infections. No studies on the relationship of CC1 S. aureus between colonization and infection have been published. METHODS:To figure out if there are some significant factors in CC1 S. aureus help its colonization or infection, 15 CC1 S. aureus isolates including ten from colonization and five from bloodstream infections were enrolled in this study. Whole-genome sequencing and bioinformatics analysis were performed. RESULTS:Virulence factor regulators XdrA, YSIRK signal peptide, CPBP family and OmpR family specifically found in infection isolates can promote virulence factors and enhance the pathogenicity of S. aureus. In addition, some significant differences in metabolism and human diseases were discovered between colonization and infection. Fst family of type I toxin-antitoxin system that mainly maintains stable inheritance was specifically found in CC1 S. aureus colonization isolates and might help S. aureus survive for colonization. No significant differences in genomic evolutionary relationship were found among CC1 S. aureus isolates between colonization and infection. CONCLUSIONS:Virulence factor regulators and metabolic state can promote CC1 S. aureus pathogenic process compared with colonization, and it seems that the strains of colonization origin cannot have pathogenic potential. Experimental confirmation and a bigger number of CC1 S. aureus strains are necessary for further study about the details and mechanism between colonization and infection.

1 前言 碳青霉烯类抗菌药物包括亚胺培南、美罗培南和厄他培南等,是治疗多重耐药革兰阴性菌所致感染最有效的抗菌药物之一.随着该类药物在临床的广泛使用,碳青霉烯类耐药细菌(carbapenem-resistant organisms, CRO)的检出率呈逐年上升趋势,其中以肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌为代表.CHINET中国细菌耐药监测网2021年监测结果显示,我国临床分离肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌对亚胺培南的耐药率分别为23.1％、23％和71.5％[1-2].

目的 了解2015-2021年国内主要地区医疗机构临床分离链球菌属细菌对抗菌药物的耐药性.方法 对国内主要地区51所医院临床分离的链球菌属采用纸片扩散法(K-B法)或E试验方法或自动化商业药敏测试系统,按CHINET统一监测方案进行抗菌药物敏感性试验,并按2022年CLSI折点标准统计分析总结.结果 2015-2021年共收集到89 684株链球菌属细菌,包括肺炎链球菌35 254株(39.3％),β溶血链球菌42 563株(47.6％),草绿色链球菌11 767株(13.1％).42 563株β溶血链球菌中A群、B群以及未能鉴定分型的链球菌分别为39.8％、52.8％、7.4％.非脑脊液样本儿童患者分离的25 552株肺炎链球菌中青霉类敏感、中介、耐药(PSSP、PISP、PRSP)菌株的检出率分别为86.2％～97.7％、1.7％～6.5％和0.6％～7.3％,在成人患者7 997株中的检出率分别为92.0％～95.1％、3.8％～5.3％和1.4％～2.7％.脑脊液分离肺炎链球菌PRSP占比81.2％.无论是脑脊液或非脑脊液分离儿童和成人的肺炎链球菌对红霉素和克林霉素高度耐药,耐药率均在90％以上.β溶血链球菌对青霉素和头孢曲松均敏感,未发现耐药菌株;草绿色链球菌对青霉素的耐药率为5.7％～8.5％.46.3％～55.0％的B群β溶血链球菌对左氧氟沙星耐药,其他链球菌对左氧氟沙星仍十分敏感.链球菌属细菌中未发现利奈唑胺和万古霉素的耐药株.结论 青霉素仍是链球菌属非中枢神经系统感染的首选药物.链球菌属持续对红霉素、克林霉素高浓度耐药.

The dissemination of carbapenem-resistant Gram-negative bacilli (CRGNB) is a global public health issue. CRGNB isolates are usually extensively drug-resistant or pandrugresistant, resulting in limited antimicrobial treatment options and high mortality. A multidisciplinary guideline development group covering clinical infectious diseases, clinical microbiology, clinical pharmacology, infection control, and guideline methodology experts jointly developed the present clinical practice guidelines based on best available scientific evidence to address the clinical issues regarding laboratory testing, antimicrobial therapy, and prevention of CRGNB infections. This guideline focuses on carbapenem-resistant Enterobacteriales (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Sixteen clinical questions were proposed from the perspective of current clinical practice and translated into research questions using PICO (population, intervention, comparator, and outcomes) format to collect and synthesize relevant evidence to inform corresponding recommendations. The grading of recommendations, assessment, development and evaluation (GRADE) approach was used to evaluate the quality of evidence, benefit and risk profile of corresponding interventions and formulate recommendations or suggestions. Evidence extracted from systematic reviews and randomized controlled trials (RCTs) was considered preferentially for treatment-related clinical questions. Observational studies, non-controlled studies, and expert opinions were considered as supplementary evidence in the absence of RCTs. The strength of recommendations was classified as strong or conditional (weak). The evidence informing recommendations derives from studies worldwide, while the implementation suggestions combined the Chinese experience. The target audience of this guideline is clinician and related professionals involved in management of infectious diseases. Copyright 2023, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction Polymyxin-resistant Enterobacterales poses a significant threat to public health globally, but its prevalence and genomic diversity within a sole hospital is less well known. In this study, the prevalence of polymyxin-resistant Enterobacterales in a Chinese teaching hospital was investigated with deciphering of their genetic determinants of drug resistance. Methods Polymyxin-resistant Enterobacterales isolates identified by matrix-assisted laser desorption were collected in Ruijin Hospital from May to December in 2021. Both the VITEK 2 Compact and broth dilution methods were used to determine polymyxin B (PMB) susceptibility. Polymyxin-resistant isolates were further characterized by molecular typing using PCR, multi-locus sequence typing, and sequencing of the whole genome. Results Of the 1,216 isolates collected, 32 (2.6%) across 12 wards were polymyxin-resistant (minimum inhibitory concentration (MIC) range, PMB 4–256 mg/ml, and colistin 4 ≥ 16 mg/ ml). A total of 28 (87.5%) of the polymyxin-resistant isolates had reduced susceptibility to imipenem and meropenem (MIC ≥ 16 mg/ml). Of the 32 patients, 15 patients received PMB treatment and 20 survived before discharge. The phylogenetic tree of these isolates showed they belonged to different clones and had multiple origins. The polymyxin-resistant Klebsiella pneumoniae isolates belonged to ST-11 (85.72%), ST-15 (10.71%), and ST-65 (3.57%), and the polymyxin-resistant Escherichia coli belonged to four different sequence types, namely, ST-69 (25.00%), ST-38 (25.00%), ST-648 (25.00%), and ST-1193 (25.00%). In addition, six mgrB specific mutations (snp_ALT c.323T>C and amino acid change p.Val8Ala) were identified in 15.6% (5/32) of the isolates. mcr -1, a plasmid-mediated polymyxin-resistant gene, was found in three isolates, and non-synonymous mutations including T157P, A246T, G53V, and I44L were also observed. Discussion In our study, a low prevalence of polymyxin-resistant Enterobacterales was observed, but these isolates were also identified as multidrug resistant. Therefore, efficient infection control measures should be implemented to prevent the further spread of resistance to last-line polymyxin therapy.

目的 了解2015-2021年我国不同地区51家医院分离的不动杆菌属分布情况和耐药变迁趋势.方法 按CHINET耐药监测方案,采用纸片扩散法或自动化仪器法对收集的菌株进行药敏试验,按CLSI 2021 年版标准判读药敏结果,采用WHONET 5.6 软件进行数据分析.结果 在此期间共分离到不动杆菌属 143 393 株,其中鲍曼不动杆菌是最常见的菌种,占所有不动杆菌属的 89.6%.呼吸道样本分离最常见的是不动杆菌属,占所有样本分离株的 73.0%.94.0%的菌株分离自住院患者,其中ICU分离的菌株占 35.5%.除米诺环素、替加环素和多黏菌素B外,不动杆菌属对其他抗菌药物如β内酰胺类、氨基糖苷类和氟喹诺酮类等耐药率较高.不同等级医院和不同科室分离的不动杆菌属对抗菌药物的耐药率存在差异.2015-2021 年鲍曼不动杆菌对头孢哌酮-舒巴坦和哌拉西林-他唑巴坦耐药率呈现上升趋势,而对替加环素和米诺环素的耐药率呈现下降趋势.碳青霉烯类耐药的鲍曼不动杆菌分离率较高,在三级医院达75.2%.结论 不动杆菌属是医院感染的重要病原菌,对临床常用抗菌药物呈现较高的耐药性.对于多重耐药不动杆菌属感染,可以采用多黏菌素B、替加环素和米诺环素等抗菌药物治疗.

探讨新型冠状病毒(新冠)病救治临时定点医院的工作人员医院感染(院感)防控管理的方案.外派医疗队入驻外院新冠感染定点医院时,工作人员面临病区布局不熟悉、收治任务时间紧以及培训时间不足这三个问题.为确保安全完成收治新冠感染患者的任务,迫切需要制定合理的院感防控管理方案.本感控方案针对以上问题,就人员培训、多举措检查督导、制度保障与清洁区域驻地酒店管理等具体措施进行规划及落实.该方案在2022年3月至4月,应用于上海市老年医学中心瑞金医疗队院感防控,并取得了全队零感染的目标.本感控方案安全且有效,可用于新冠感染定点医院实施感染防控,也能为今后的抗疫工作提供参考.

目的 分析2016-2020年某三级综合医院耐碳青霉烯类肺炎克雷伯菌(CRKP)检出情况及变化趋势.方法 回顾分析2016年1月1日-2020年12月31日上海交通大学医学院附属瑞金医院住院患者标本中分离的CRKP,比较不同年度、不同科室、不同标本类型中CRKP检出率的变化趋势,使用卡方检验及Cochran-Armit-age趋势检验对调查数据进行统计分析.结果 2016-2020年医院整体CRKP检出率有所波动,其差异有统计学意义(χ2=52.457,P<0.001),不同年份间CRKP检出率并未呈现上升或下降趋势(Z=0.130,P=0.896).CRKP主要来源于重症监护科(ICU)及烧伤科,主要标本来源为痰液.胰腺外科CRKP检出率从2016年至2020年逐年上升(P<0.05).CRKP对磷霉素耐药率逐年下降(P<0.05),对替加环素耐药率逐年上升(P<0.05).结论 医院CRKP检出率处于国内较高水平,不同科室、不同标本来源检出率存在差别,其中ICU及深静脉导管标本中历年CRKP检出率均在50％以上.CRKP对常见抗菌药物高度耐药.

Polymyxin-resistant Pseudomonas aeruginosa is a major threat to public health globally. We investigated the prevalence of polymyxin-resistant P. aeruginosa in a Chinese teaching hospital and determined the genetic and drug-resistant phenotypes of the resistant isolates. P. aeruginosa isolates identified by MALDI-TOF MS were collected across a 3-month period in Ruijin Hospital. Antimicrobial susceptibility was determined by a Vitek-2 Compact system with broth dilution used to determine polymyxin B (PMB) susceptibility. Polymyxin-resistant isolates were further characterized by molecular typing using PCR, multi-locus sequence typing (MLST) and whole-genome sequencing. Phylogenetic relationships were analyzed using single nucleotide polymorphism (SNP) from the whole-genome sequencing. Of 362 P. aeruginosa isolates collected, 8 (2.2%) isolates from separate patients across six wards were polymyxin-resistant (MIC range, PMB 4–16 μg/mL and colistin 4–≥16 μg/mL). Four patients received PMB treatments (intravenous, aerosolized and/or topical) and all patients survived to discharge. All polymyxin-resistant isolates were genetically related and were assigned to five different clades (Isolate 150 and Isolate 211 being the same ST823 type). Genetic variations V51I, Y345H, G68S and R155H in pmrB and L71R in pmrA were identified, which might confer polymyxin resistance in these isolates. Six of the polymyxin-resistant isolates showed reduced susceptibility to imipenem and meropenem (MIC range ≥ 16 μg/mL), while two of the eight isolates were resistant to ceftazidime. We revealed a low prevalence of polymyxin-resistant P. aeruginosa in a Chinese teaching hospital with most polymyxin-resistant isolates being multidrug-resistant. Therefore, effective infection control measures are urgently needed to prevent further spread of resistance to the last-line polymyxins.

BackgroundBloodstream infections (BSIs), especially hospital-acquired BSIs, are a major cause of morbidity and mortality. However, the details about the pathogens and antimicrobial resistance profile of BSIs across China are still lacking.MethodsAn investigation was conducted in 10 large teaching hospitals from seven geographic regions across China in 2016 based on China Antimicrobial Surveillance Network (CHINET) to profile the clinical and etiological features of BSIs.ResultsA total of 2,773 cases of BSIs were identified, a majority (97.3%) of which were monomicrobial. Overall, 38.4% (1,065/2,773) were community-acquired BSIs (CABSIs), and 61.6% (1,708/2,773) were hospital-acquired BSIs (HABSIs). Of the 2,861 pathogenic BSI isolates, 67.5% were Gram-negative bacteria, 29.6% were Gram-positive bacteria, and 2.9% were fungi. The top BSI pathogens were Escherichia coli, Klebsiella pneumoniae, coagulase-negative Staphylococci (CNS), Staphylococcus aureus, Enterococci, and Acinetobacter baumannii. Escherichia coli and K. pneumoniae isolates showed low susceptibility to penicillins, cephalosporins (except ceftazidime and cefepime), and ampicillin-sulbactam (13.1%–43.4% susceptible); moderate susceptibility (about 60% susceptible) to ceftazidime, cefepime, and aztreonam; and high susceptibility (>90%) to β-lactam/β-lactamase inhibitor combinations other than ampicillin-sulbactam, except K. pneumoniae strains to piperacillin-tazobactam (59.2% susceptible). HABSIs were associated with significantly higher prevalence of carbapenem-resistant and extended-spectrum β-lactamases-producing K. pneumoniae, methicillin-resistant S. aureus, methicillin-resistant CNS, and ampicillin-resistant Enterococci than CABSIs. Overall, 42.0% of the BSI due to S. aureus strains were resistant to methicillin.ConclusionsThe findings about BSIs in teaching hospitals across China add more scientific evidence to inform the appropriate management of the disease.

当前,细菌耐药已成为全球公共健康领域的重大挑战,其中尤以碳青霉烯类耐药肠杆菌目细菌(carbapenem-resistant Enterobacterales, CRE)引起的感染形势最为严峻.碳青霉烯类抗生素包括亚胺培南、美罗培南和厄他培南等,是治疗多重耐药革兰阴性杆菌所致感染最有效的抗菌药物之一.

Objective To investigate the susceptibility and resistance of clinical isolates collected from hospitals in several regions of China.Methods These clinical strains were collected from 51 hospitals.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were analyzed according to CLSI 2021 breakpoints.Results A total of 301 917 clinical isolates were collected from January to December 2021,of which gram negative organisms and gram positive cocci accounted for 71.4% and 28.6% respectively.Methicillin-resistant strains in S.aureus （MRSA）,S.epidermidis and other Staphylococcus species （except S.pseudintermedius and S.schleiferi） accounted for 30.0%,80.7% and 77.7% respectively.MR strains showed much higher resistance rates to most of other antimicrobial agents than MS strains.However,92.4% of MRSA strains were still susceptible to trimethoprim-sulfamethoxazole,while 90.7% of MRSE strains were susceptible to rifampin.No staphylococcal strains were found resistant to vancomycin.E.faecalis strains demonstrated much lower resistance rates to most of the drugs tested than E.faecium.A few strains of both Enterococcus species were resistant to vancomycin.The prevalence of PSSP was 97.8% in the non-meningitis S.pneumoniae isolates from children and 95.1% in the non-meningitis S.pneumoniae isolates from adults.The Enterobacterales strains were still highly susceptible to carbapenems.Overall,less than 13% of these strains were resistant to carbapenems.K.pneumoniae isolates showed increasing resistance rates to imipenem and meropenem,from 3.0% and 2.9% in 2005 to 25.0% and 26.3% in 2018.However,the resistance rates of Klebsiella pneumoniae to imipenem and meropenem decreased since 2019.About 65.6% and 66.5% of Acinetobacter spp.were resistant to imipenem and meropenem,respectively.Overall,23.0% and 18.9% of the Pseudomonas aeruginosa isolates were resistant to imipenem and meropenem,respectively.Conclusions Bacterial resistance to commonly used antibiotics is still on the rise.However,the prevalence of carbapenem-resistant K.pneumoniae and P.aeruginosa is decreasing in recent years.It is suggested that strengthening the monitoring of bacterial resistance and multidisciplinary teamwork are effective in controlling the spread of drug-resistant bacteria.

Research indicates that Staphylococcus aureus colonization in the elderly with predisposing risks is associated with subsequent infection. However, the molecular epidemiology and risk factors for S. aureus colonization among residents and staff in nursing homes (NHs) in China remain unclear. A multicenter study was conducted in three NHs in Shanghai between September 2019 and October 2019. We explored the prevalence, molecular epidemiology, and risk factors for S. aureus colonization. All S. aureus isolates were characterized based on antimicrobial resistance, virulence genes, multilocus sequence typing (MLST), staphylococcus protein A (spa) typing, and staphylococcal cassette chromosome mec (SCCmec) typing. NH records were examined for potential risk factors for S. aureus colonization. S. aureus and methicillin-resistant S. aureus (MRSA) isolates were detected in 109 (100 residents and 9 staff, 19.8%, 109/551) and 28 (24 residents and 4 staff, 5.1%, 28/551) subjects among 496 residents and 55 staff screened, respectively. Compared to methicillin-susceptible S. aureus isolates, all 30 MRSA isolates had higher resistance rates to most antibiotics except minocycline, rifampicin, linezolid, vancomycin, and teicoplanin. Sequence type (ST) 1 (21.3%) was the most common sequence type, and t127 (20.5%) was the most common spa type among 122 S. aureus isolates. SCCmec type I (70%) was the dominant clone among all MRSA isolates. CC1 (26/122, 21.3%) was the predominant complex clone (CC), followed by CC398 (25/122, 20.5%), CC5 (20/122, 16.4%) and CC188 (18/122, 14.8%). Female sex (OR, 1.70; 95% CI, 1.04–2.79; P = 0.036) and invasive devices (OR, 2.19; 95% CI, 1.26–3.81; P = 0.006) were independently associated with S. aureus colonization.

Tigecycline is an alternative antibiotic for managing carbapenem-resistant Gram-negative bacterial infections. However, disk diffusion and automated testing often show false-intermediate or false-resistant results in tigecycline susceptibility, misleading clinical antimicrobial therapy. Broth microdilution (BMD) is the reference method for testing tigecycline susceptibility, but it is labor intensive and time consuming to perform in clinical laboratories. Therefore, a simple and accurate method is urgently needed. We evaluated the performance of VITEK 2, E-test, Kirby–Bauer disk diffusion (KB), and modified KB disk diffusion (mKB) versus BMD in testing tigecycline susceptibility of 372 strains of carbapenem-resistant Klebsiella pneumoniae (CRKP) and 346 strains of carbapenem-resistant Acinetobacter baumannii (CRAB). BMD confirmed that 96.8% of CRKP and 91% of CRAB strains were susceptible to tigecycline. E-test, VITEK 2, KB, and mKB yielded categorical agreement of 96.7/59.3%, 69.9/54.3%, 78.5/87.3%, and 96.5%/91% for CRKP/CRAB, respectively. No very major error was found for either CRKP or CRAB by any method. No major error was found for CRKP or CRAB by the mKB method. The mKB method enhanced by R-buffer is simple, accurate, and inexpensive for clinical laboratories to test the susceptibility of CRKP and CRAB isolates to tigecycline.

Carbapenemresistant organism(CRO) includes carbapenem resistant Enterobacteriaceae(CRE), carbapenem resistan t Acinetobacter baumannii(CRAB) and carbapenem resistant Pseudomonas aeruginosa (CRPA) , which are currently the most threatening multi-drug resistant bacteria. The situation of CRO infection in our country is very serious. In this paper, the prevalence and trend of CRO and the epidemic characteristics of CRE carbapenemase are briefly discussed.

目的 监测国内主要地区医疗机构临床分离菌对抗菌药物的敏感性.方法 对全国52所医院临床分离菌采用纸片扩散法或自动化仪器法按CHINET统一监测方案进行抗菌药物敏感性试验.按2020年CLSI折点标准判断结果.结果 收集2020年1—12月上述医院临床分离菌共251135株,其中革兰阳性菌占28.1％,革兰阴性菌占71.9％.金黄色葡萄球菌、表皮葡萄球菌和其他凝固酶阴性葡萄球菌(除假中间葡萄球菌和施氏葡萄球菌外)中甲氧西林耐药株(MRSA、MRSE和其他MRCNS)的检出率分别为31.0％、81.7％和77.5％,甲氧西林耐药株对绝大多数抗菌药物的耐药率均显著高于甲氧西林敏感株(MSSA、MSSE和其他MSCNS).MRSA中有93.6％菌株对甲氧苄啶-磺胺甲噁唑敏感;MRSE中有89.9％的菌株对利福平敏感;未发现万古霉素耐药株.肠球菌属中粪肠球菌对多数测试抗菌药物的耐药率均显著低于屎肠球菌,两者中均有少数万古霉素耐药株.2020年儿童和成人中分离的非脑膜炎肺炎链球菌中青霉素敏感株(PSSP)(96.7％和95.5％)所占比例较2019年有所上升,青霉素中介和耐药株(PISP和PRSP)的检出率有所下降.除克雷伯菌属对亚胺培南和美罗培南的耐药率分别为21.5％和22.4％外,肠杆菌目细菌对碳青霉烯类抗生素仍高度敏感,多数菌属的耐药率低于12％.2005—2020年16年的监测显示,肺炎克雷伯菌对亚胺培南和美罗培南的耐药率从2005年的3.0％和2.9％持续上升至2018年的25.0％和26.3％,但从2019年和2020年开始呈连续下降趋势.此外,不动杆菌属对亚胺培南和美罗培南的耐药率分别为68.1％和69.0％,铜绿假单胞菌对上述两药的耐药率分别为23.2％和19.3％.结论 临床分离菌对常见抗菌药物的耐药率虽仍呈增长趋势,但如碳青霉烯类耐药的肺炎克雷伯菌和铜绿假单胞菌等多种重要的碳青霉烯类耐药细菌的检出率在多年升高的情况下,近年来呈现连续下降趋势,提示加强细菌耐药监测,结合医院感染预防控制措施,对控制耐药细菌的流行播散是行之有效的.

Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) is an important issue associated with significant morbidity and mortality and well known as a predominant pathogen causing bloodstream infection (BSIs) globally. To estimate the antibiotic resistance and molecular characteristics of S. aureus causing BSIs in Shanghai, 120 S. aureus isolates (20 isolates each year) from the patients with S. aureus BSIs from 2013 to 2018 were randomly selected and enrolled in this study. Fifty-three (44.2%) MRSA isolates were determined, and no isolate was found resistant to vancomycin, daptomycin, synercid, linezolid and ceftaroline. The toxin genes tst, sec, seg and sei were found more frequently among MRSA isolates compared with MSSA isolates (all P < 0.0001). Twenty-nine sequence types (STs) were identified, and ST5 (23.3%) was the most common ST, followed by ST398 (11.7%) and ST764 (10.0%). SCCmec II (73.6%) was the most frequent SCCmec type among MRSA isolates. The dominant clonal complexes (CCs) were CC5 (ST5, ST764, ST965 and ST3066; 36.7%) and the livestock-associated clone CC398 (ST398, 11.7%). MRSA-CC5 was the predominant CC among MRSA isolates (37/53, 69.8%), and CC5-II MRSA was found in 34 isolates accounting for 91.9% (34/37) among CC5 MRSA isolates. In addition, all 29 tst-positive MRSA isolates were CC5-MRSA as well. Our study provided the properties and genotypes of S. aureus causing BSIs at Ruijin Hospital in Shanghai from 2013 to 2018, and might suggest of value clues for the further study insights into pathogenic mechanisms intrinsically referring to the development of human-adapted S. aureus clones and their diffusions.

目的 监测国内主要地区医疗机构临床分离菌对抗菌药物的敏感性.方法 对国内主要地区36所三级医院临床分离菌采用纸片扩散法或自动化仪器法按CHINET统一监测方案进行抗菌药物敏感性试验.按CLSI文件标准判断结果.结果 收集2019年1-12月上述医院临床分离菌共249 758株,其中革兰阳性菌占29.0％,革兰阴性菌占71.0％.金黄色葡萄球菌、表皮葡萄球菌和其他凝固酶阴性葡萄球菌(除假中间葡萄球菌和施氏葡萄球菌)中甲氧西林耐药株的检出率分别为31.4％、82.4％和78.3％.甲氧西林耐药株(MRSA、MRSE和MRCNS)对绝大多数抗菌药物的耐药率均显著高于甲氧西林敏感株(MSSA、MSSE和MSCNS).MRSA中有92.6％的菌株对甲氧苄啶-磺胺甲(口恶)唑敏感;MRSE中有89.0％的菌株对利福平敏感;未发现万古霉素耐药株.肠球菌属中粪肠球菌对多数测试抗菌药物的耐药率均显著低于屎肠球菌,两者中均有少数万古霉素耐药株.2019年儿童和成人中分离的肺炎链球菌中PSSP(95.2％和95.3％)所占比例较2018年有所上升,PISP和PRSP的检出率有所下降.除肺炎克雷伯菌对碳青霉烯类的耐药率为27.6％外,肠杆菌科细菌对碳青霉烯类抗生素仍高度敏感,多数菌属的耐药率低于10％.2005-2019年15年的监测数据显示肺炎克雷伯菌对亚胺培南和美罗培南的耐药率呈持续上升趋势(3.0％和2.9％对25.3％和26.8％).此外,不动杆菌属对亚胺培南和美罗培南的耐药率分别为73.6％和75.1％;铜绿假单胞菌对上述两药的耐药率分别为27.5％和23.5％.结论 临床分离菌对常用抗菌药物的耐药率仍呈增长趋势,尤其是碳青霉烯类耐药革兰阴性杆菌.为应对严峻的全国细菌耐药形势,需各相关部门协作以遏制细菌耐药.

Background: Quinolones are commonly used for treatment of infections by bacteria of the Enterobacteriaceae family. However, the rising resistance to quinolones worldwide poses a major clinical and public health risk. This study aimed to characterise a novel multiple resistance plasmid carrying three plasmid-mediated quinolone resistance genes in Escherichia coli clinical stain RJ749. Methods: MICs of ceftriaxone, cefepime, ceftazidime, ciprofloxacin, and levofloxacin for RJ749 and transconjugant c749 were determined by the Etest method. Conjugation was performed using sodium azide-resistant E. coli J53 strain as a recipient. The quinolone resistance-determining regions of gyrA, gyrB, parC, and parE were PCR-amplified. Results: RJ749 was highly resistant to quinolones, while c749 showed low-level resistance. S1-nuclease pulsed-field gel electrophoresis revealed that RJ749 and c749 both harboured a plasmid. PCR presented chromosomal mutation sites of the quinolone resistance-determining region, which mediated quinolone resistance. The c749 genome comprised a single plasmid, pRJ749, with a multiple resistance region, including three plasmid-mediated quinolone resistance (PMQR) genes (aac(6′)-Ib-cr, qnrS2, and oqxAB) and ten acquired resistance genes. One of the genes, qnrS2, was shown for the first time to be flanked by two IS26s. Three IS26-mediated circular molecules carrying the PMQR genes were detected. Conclusions: We revealed the coexistence of three PMQR genes on a multiple resistance plasmid and a new surrounding genetic structure of qnrS2 flanked by IS26 elements. IS26 plays an important role in horizontal spread of quinolone resistance.