Background: Vancomycin-resistant Enterococcus (VRE) can be carried in the gut for a long period and its carriage status is associated with subsequent infections. This study aimed to investigate the frequency of intestinal VRE carriage in intensive care patients in Beijing. Methods: A multicenter, retrospective cross-sectional study was conducted at six hospitals in Beijing, China. All patients admitted to intensive care units (ICUs) between April 2 and May 1, 2017, were enrolled, and their clinical data were gathered by reviewing electronic medical records. Rectal swabs collected from patients were stored at -80 degrees C in the Institute of Clinical Pharmacology, Peking University First Hospital, and they were selectively cultured for VRE, then the identified strains were analyzed by polymerase chain reaction (PCR) to detect the glycopeptide resistance gene and were characterized by multilocus sequence typing (MLST). Results: Of 148 patients recruited, 46 (31.1%) carried VRE, with the majority (n Z 42) being Enterococcus faecium. In total, 78.3% of the VRE were vanA positive and 15.2% vanM positive, while 6.5% undetected glycopeptide resistance gene. The predominant ST was ST78 (47.6%) followed by ST192 (14.3%), ST555 (9.5%), and ST789 (9.5%). Multivariate analysis showed that factors associated VRE carriage were patients aged >65 years (odds ratio [OR], 3.786; 95% confidence interval [CI], 1.402-10.222) and recent third-generation cephalosporins use (OR, 6.360; 95% CI, 1.873-21.601).

目的 监测2017年至2020年临床分离得到大肠埃希菌中多黏菌素耐药mcr-1阳性菌株的分子流行病学特征.方法 使用聚合酶链反应技术筛查mcr-1阳性菌株从临床分离的1518株大肠埃希菌.采用16SrRNA验证所有纳入分析的mcr-1阳性菌株的菌种.使用微量肉汤法与琼脂二倍稀释法进行抗菌药物敏感实验.所有mcr-1阳性菌株通过多位点序列分型(MLST)进行同源性分析.结果 在1518株临床分离大肠埃希菌中,检测到14株(0.92％)携带mcr-1基因的大肠埃希菌.微量肉汤法显示14株mcr-1阳性菌株均对多黏菌素耐药.16SrRNA验证14株mcr-1阳性菌株类型均为大肠埃希菌.14株阳性菌株对临床常用抗菌药物中的第三、四代头孢菌素、单环β-内酰胺类以及喹诺酮类等都表现出较高的耐药率,尤其阳性菌株对头孢唑啉、头孢呋辛、头孢噻肟、头孢曲松、头孢他啶、头孢哌酮和头孢吡肟的耐药率在57.1％～92.9％,对氨曲南的耐药率为64.3％,对环丙沙星和左氧氟沙星的耐药率达到92.9％;14株mcr-1阳性菌对β内酰胺类酶抑制剂复合制剂和碳青霉烯类药物(亚胺培南、美罗培南和厄他培南)的耐药率较低,均为14.3％;14株mcr-1阳性菌对庆大霉素和阿米卡星的耐药率为57.1％和21.4％;对四环素和米诺环素耐药率分别为85.7％和64.3％,但是均对替加环素表现为敏感.MLST分析显示14株mcr-1阳性菌株分别获得14种不同STs分型.对14株阳性菌株进行聚类分析显示较为分散,相似度低于60％.结论 临床分离的大肠杆菌mcr-1阳性菌株的检出率低于往年.14个不同的ST分型显示mcr-1阳性大肠埃希菌的遗传多样性.应进一步关注阳性菌株的多重耐药表型和传播.

目的：分析血清甲状腺激素检验在甲状腺疾病诊断中的应用。方法：本次研究对本院2021年4月-2022年2月收入的血清甲状腺激素检验对象进行对照分析，抽取48例非甲状腺疾病体检对象作为对照组，另选择48例确诊甲状腺疾病患者作为观察组；对比两组对象的相关激素水平差异，甲亢和甲减患者治疗前后的激素水平改善情况。结果：观察组和对照组的血清甲状腺激素比较有显著差异（P<0．05），确诊患者中甲减和甲亢患者的数量多且占比均匀，其中甲亢患者FT3、FT4、TT3及TT4水平显著高于对照组和甲减患者，甲亢患者S-TSH水平

Background:The clinical use of carbapenems is facing challenges due to increased carbapenemase-producing Escherichia coli (CP-EC) infections over the past decade. Meanwhile, whole-genome sequencing (WGS) is an important method for bacterial epidemiological research. We aim to provide more gene-based surveys to explore the genomics and occurrence of CP-EC in China.Methods:A total of 780 Escherichia coli isolates were collected by the China Antimicrobial Resistance Surveillance Trial (CARST) from 2019 to 2020. An antibacterial susceptibility test was performed by using the agar dilution method. CP-EC were detected by the modified carbapenem inactivation method (mCIM), EDTA-modified carbapenem inactivation method (eCIM), and polymerase chain reaction (PCR). Homology analysis was performed by multilocus sequence typing (MLST). A conjugation experiment was performed to verify the transferability of plasmids carrying carbapenemase genes. WGS was conducted to explore the gene-environment of the carbapenemase gene.Result:Of the 780 Escherichia coli isolates, 31 isolates were insensitive to carbapenem with a rate of 4%. Among them, 13 CP-EC isolates had transferability of the bla NDM gene. These isolates belonged to nine distinct sequence types (STs), with some correlation. We found that two (2/13, 15.4%) of the CP-EC isolates that were collected from blood specimens were highly pathogenic and also showed high transferability of the bla NDM gene. In addition, eight (8/13, 61.5%) of the CP-EC isolates were found to be multidrug-resistant.Conclusion:With the increasing use of carbapenem, CP-EC isolates accounted for nearly half of the total carbapenem-insensitive Escherichia coli isolates. Our findings highlight the urgent need to pay attention to CP-EC isolates in bloodstream infections and ESBL-producing CP-EC isolates. Based on the One Health concept, we suggest various measures, including the development of bacterial vaccines, antibiotic management, and establishment of better medical environments, to avoid the outbreak of CP-EC.

世界卫生组织公布了需优先研发新型抗生素的病原菌,分别为碳青霉烯类耐药鲍曼不动杆菌、碳青霉烯类耐药铜绿假单胞菌、碳青霉烯类耐药肠杆菌科细菌及第三代头孢菌素耐药肠杆菌科细菌[1].

目的 监测我国主要城市三级甲等医院住院患者分离的革兰氏阴性菌的细菌耐药状况,掌握耐药流行趋势,为抗生素合理使用提供科学数据.方法 定点收集来自全国19家医院临床分离细菌,由中心实验室统一用平皿/肉汤二倍稀释法测定抗菌药物最低抑菌浓度(MIC)值.结果 对2019年7月至2020年6月来自全国19座城市19家医院的4795株临床分离致病菌进行了MIC测定.结果 显示,大肠埃希菌和肺炎克雷伯菌中超广谱β内酰胺酶(ESBLs)表型检出率分别为52.8％和23.6％,均持续下降,碳青霉烯类耐药肺炎克雷伯菌比例与前次监测持平.对肠杆菌目细菌抗菌作用较好的药物包括碳青霉烯类、阿米卡星、拉氧头孢、β内酰胺类合剂、磷霉素氨丁三醇和西他沙星等.非发酵革兰阴性菌中铜绿假单胞菌和鲍曼不动杆菌对亚安培南的耐药率分别为27.1％和70.7％,多重耐药菌(MDR)检出率分别为39.7％和74.9％,泛耐药菌(XDR)检出率分别为11.8％和69.0％.不同病房、不同年龄以及不同标本来源菌株耐药率比较提示,重症监护病房分离肺炎克雷伯菌、鲍曼不动杆菌和铜绿假单胞菌中MDR占比更高,儿童患者分离肺炎克雷伯菌中ESBLs检出率高于成人和老年人,我国儿童中细菌耐药问题不容忽视.结论 ESBLs检出率有所下降;碳青霉烯类耐药肺炎克雷伯菌、铜绿假单胞菌、鲍曼不动杆菌比例稳定;鲍曼不动杆菌对米诺环素耐药率有所升高,值得注意.

目的 对碳青霉烯类耐药大肠埃希菌的分子流行病学进行调查.方法 通过微量肉汤稀释法测定中国细菌耐药监测研究(CARST)于2019年至2020年收集的大肠埃希菌的最低抑菌浓度;通过改良碳青霉烯灭活试验(mCIM)、EDTA改良碳青霉烯灭活试验(eCIM)检测菌株的碳青霉烯酶表型;通过聚合酶链反应和Sanger测序检测碳青霉烯酶相关耐药基因;通过接合实验验证碳青霉烯酶耐药基因所在质粒的水平传递性;通过多位点序列分型对碳青霉烯类耐药菌株进行同源性分析.结果 36株对美罗培南或亚胺培南或厄他培南不敏感的菌株中22株只对厄他培南耐药.只对厄他培南耐药的22株大肠埃希菌碳青霉烯酶检测均为阴性,对美罗培南或亚胺培南耐药的14株大肠埃希菌碳青霉烯酶检测均为阳性,分别有8株携带blaNDM-5,3株携带blaNDM-1,1株携带blaNDM-7,1株携带blaNDM-16,1株碳青霉烯酶基因未测得.7株blaNDM-5阳性菌株、3株blaNDM-1阳性菌株、1株blaNDM-7阳性菌株和1株blaNDM-16阳性菌株可以通过接合实验使大肠埃希菌J53获得碳青霉烯抗性.14株碳青霉烯酶所致耐药的大肠埃希菌分属9个ST型,部分有关联.结论 临床上只对厄他培南耐药但对亚胺培南和美罗培南敏感菌株的耐药性主要为非产碳青霉烯酶所致.而对亚胺培南或美罗培南耐药的14株菌mCIM和eCIM同时为阳性,提示临床分离株对亚胺培南或美罗培南耐药时,耐药机制较可能为产金属碳青霉烯酶.

目的 评价2种利奈唑胺片在中国健康受试者的生物等效性.方法 按单中心、随机、开放、单剂量、两制剂、两序列、双周期、交叉研究设计方法,随机交叉单次口服利奈唑胺片受试制剂与参比制剂600 mg,空腹状态下28例受试者完成试验,餐后状态下27例受试者完成试验,用LC-MS/MS法测定血浆中利奈唑胺的浓度,用WinNonlin 6.4软件按非房室模型计算药代动力学参数,并进行生物等效性评价.结果 受试者口服利奈唑胺片受试制剂与参比制剂600 mg后,在空腹状态下给药的血浆主要药代动力学参数如下:Cmax分别为(15.88±4.31)和(15.34±4.56)μg·mL-1,tmax分别为(1.08±0.98)和(1.22±0.92)h,AUC0-t分别为(111.22±32.45)和(114.86±39.54)μg·mL-1·h,AUC0-∞分别为(117.72±35.09)和(120.38±42.47)μg·mL-1·h;在餐后状态下给药的血浆主要药代动力学参数如下:Cmax分别为(13.84±3.44)和(13.00±3.13)μg·mL-1,tmax分别为(2.06±1.02)和(1.88±1.13)h,AUC0-t分别为(104.05±42.71)和(100.58±42.90)μg·mL-1·h,AUC0-∞分别为(110.29±44.61)和(107.56±45.46)μg·mL-1·h.2种制剂的Cmax、AUC0-t和AUC0-∞经对数转换后90％置信区间在空腹状态下分别为96.71％～112.66％,92.71％～103.20％和93.56％～104.71％;在餐后状态下分别为97.31％～117.12％,94.52％～114.07％和93.45％～113.55％.结论 无论空腹还是餐后单次口服2种利奈唑胺片在中国健康受试者体内均具有生物等效性.

目的 探讨中国健康受试者细胞色素P4502C9(CYP2C9)和通道亚家族J成员11基因(KCNJ11)基因多态性对格列喹酮药代动力学(PK)的影响.方法 将48例中国健康受试者,单次给予格列喹酮片30 mg,用液相色谱串联质谱法测定格列喹酮血样浓度,计算PK参数,比较不同基因型对Cmax、AUC0-t、AUC0-∞、tmax和t1/2的影响.结果 口服格列喹酮片后,CYP2C93为AA和AC基因型的Cmax分别为(482.02±166.28)和(821.83±255.92)ng·mL-1,t1/2分别为(9.90±4.27)和(5.21±1.17)h,AUC0-t分别为(3053.76±816.14)和(4985.33±1206.58)ng·mL-1·h,AUC0-∞分别为(3284.07±790.12)和(5103.83±1223.00)ng·mL-1·h.与CYP2C93 AA基因型相比,携带AC基因型受试者的Cmax、t1/2、AUC0-t和AUC0-∞差异均有统计学意义(P<0.01,P<0.001),对于tmax的影响差异无统计学意义(P>0.05).CYP2C927(rs7900194)和KCNJ11(rs5219)不同基因型间,主要PK参数差异均无统计学(均P>0.05).结论 CYP2C93基因多态性可能影响格列喹酮的代谢.在应用格列喹酮时,应充分考虑CYP2 C9基因多态性的影响,实现临床个体化精准用药,以保障临床用药的疗效及安全.

Objectives: XNW4107 is a novel beta-lactamase inhibitor that possesses broad activity against serine-beta-lactamases. XNW4107 in combination with imipenem exhibited potent in vitro activity against carbapenem-resistant bacteria and particularly against carbapenem-resistant Acinetobacter baumannii. This study aimed to evaluate the in vitro and in vivo antibacterial activities of imipenem/XNW4107. Methods: The minimum inhibitory concentrations, minimum bactericidal concentrations, time-kill curves, post-antibiotic effects, and spontaneous frequency of resistance were used to investigate the imipenem/XNW4107 in vitro activity. A mouse systemic infection model was used to evaluate the imipenem/XNW4107 in vivo efficacy. Results: MIC90 of imipenem/XNW4107 against imipenem-nonsusceptible A. baumannii (n = 106) was 8 mg/L, which was 16-fold lower than the MIC90 of imipenem; the resistance rate decreased from 90% to 20% applying the CLSI imipenem breakpoint. MIC90 of imipenem/XNW4107 against imipenem-resistant Klebsiella pneumoniae (n = 54) was 2 mg/L, which was 128-fold lower than the MIC90 of imipenem; 80% imipenem-nonsusceptible Pseudomonas aeruginosa (n = 101) exhibited MICs of imipenem/XNW4107 from 2 to 8 mg/L, which were 4- to 8-fold lower than the MICs of imipenem. Imipenem/XNW4107 was bactericidal against A. baumannii, K. pneumoniae, and Escherichia coli. The time-kill curves showed that increasing concentrations did not result in progressively increased killing at concentrations >4 x MIC. Imipenem/XNW4107 has a low potential for resistance development in tested strains except for K. pneumoniae. Imipenem/XNW4107 provided good protection against imipenem-resistant A. baumannii and K. pneumoniae in vivo. Conclusions: The broad-spectrum profile and potent in vitro and in vivo antibacterial activities support imipenem/XNW4107 as a promising investigational candidate. (c) 2022 The Authors. Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Purpose: The antimicrobial resistance profiles of gram-negative bacilli causing bloodstream infections have changed over time, while comprehensive and real-time surveillance data are limited in China. This study aimed to review the antimicrobial susceptibility trends among main gram-negative bacilli isolated from blood specimens in China. Methods: From 2011 to 2020, a total of 4352 non-duplicate isolates were collected from 21 tertiary hospitals in 18 provinces or cities across China. Antimicrobial susceptibility testing was conducted by the agar dilution method recommended by the Clinical and Laboratory Standards Institute (CLSI), and the results were interpreted using CLSI criteria. Results: During this 10-year surveillance period, meropenem and imipenem were the most effective agents against Escherichia coli (resistance remaining <5%). The proportion of ESBL-producing isolates in carbapenem-susceptible E. coli displayed a decreasing trend (from 72.9% to 51.2%). The resistance rates of Klebsiella pneumoniae to meropenem and imipenem increased from 3.3% and 1.6% in the 2011-12 period to 15.0% and 15.4% in the 2019-20 period, respectively. Carbapenems and amikacin were the most active agents against Enterobacter cloacae. The resistance rates of Pseudomonas aeruginosa to meropenem and imipenem increased from 13.1% and 17.7% in the 2015-16 period to 24.5% and 21.0% in the 2019-20 period, respectively. Few agents showed activity against Acinetobacter baumannii. The frequency of imipenem-non-susceptible A. baumannii remained stable (remaining similar to 70%). Conclusion: The rapid spread of carbapenem-resistant K. pneumoniae has been serious in recent years. Conversely, the prevalence of ESBL-producing isolates was decreased. Carbapenems are still effective against gram-negative bacilli causing BSIs, except for A. baumannii. More attention should be given to A. baumannii, considering its high resistance against different classes of antimicrobials.

目的 评价盐酸曲美他嗪缓释片仿制药与原研药在中国健康受试者空腹和餐后条件下给药的生物等效性与安全性.方法 按单中心、随机、开放、单剂量、两制剂、两序列、双周期、交叉研究设计,共纳入47例(空腹试验23例,餐后试验24例)成年男性和女性受试者随机交叉给药,分别单次口服受试制剂或参比制剂35 mg,用LC-MS/MS法测定血浆中曲美他嗪的浓度,用WinNonlin 6.4软件按非房室模型计算药代动力学参数,并进行生物等效性评价.结果 空腹组盐酸曲美他嗪缓释片受试制剂和参比制剂的主要药代动力学参数如下:Cmax分别为(65.62±13.92)和(66.39±15.15)μg·L-1,tmax分别为(3.96±1.15)和(4.26±1.21)h,AUC0-t分别为(909.43±219.81)和(920.65±230.09)μg·L-1·h,AUC0-∞ 分别为(921.57±226.17)和(933.35±236.56)μg·L-1·h;餐后组盐酸曲美他嗪缓释片受试制剂和参比制剂的主要药代动力学参数如下:Cmax分别为(69.78±14.65)和(65.99±13.73)μg·L-1,tmax分别为(4.83±0.82)和(4.71±1.00)h,AUC0-t分别为(766.54±165.62)和(793.50±163.67)μg·L-1·h,AUC0-∞ 分别为(774.17±167.43)和(802.04±166.02)μg·L-1·h.在空腹和餐后条件下,受试制剂和参比制剂主要药代动力学参数90％置信区间均在80.00％～125.00％.结论 空腹与餐后单次口服盐酸曲美他嗪缓释片仿制药与原研药在中国健康受试者体内均有生物等效性.

目的 对黏菌素耐药肺炎克雷伯菌的分子流行病学进行调查.方法 通过琼脂稀释法和微量肉汤稀释法测定中国细菌耐药监测研究(CARST)于2015-2018年收集的肺炎克雷伯菌的最低抑菌浓度;通过聚合酶链反应和Sanger测序检测黏菌素相关耐药基因;通过接合实验验证mcr-1和mcr-8所在质粒的水平传递性;通过多位点序列分型对黏菌素耐药菌株进行同源性分析.结果 共有29株肺炎克雷伯菌对黏菌素耐药.其中,5株携带mcr-1,4株携带mcr-8,15株菌存在双组分系统基因突变;2株mcr-1阳性菌株和1株mcr-8阳性菌株可以通过接合实验使大肠埃希菌J53获得黏菌素抗性.29株黏菌素耐药肺炎克雷伯菌分属23个ST型,彼此无明显关联.结论 黏菌素作为多重耐药肺炎克雷伯菌的少数治疗选择之一,应及时采取措施阻止其耐药情况加剧.

目的 评价中国健康受试者单次口服不同剂量羟戊基苯甲酸钾片的安全性和耐受性.方法 采用随机、双盲、安慰剂对照、单一剂量递增的单中心临床研究.合格的46例受试者随机进入5个递增剂量试验组(100 mg、200 mg、300 mg、400 mg和500 mg),100 mg和500 mg剂量组8例,其余各组10例,每个剂量组中有2例受试者口服安慰剂.用药后对受试者临床观察,定时进行实验室检查、心电图检查.结果 46例受试者全部完成了研究,研究期间,共有6例受试者发生10例次不良事件,试验组有5例受试者发生9例次不良事件,对照组有1例受试者发生1例次不良事件.试验组不良事件主要表现为恶心、头晕、碰伤、谷丙转氨酶(GPT)升高、血清淀粉酶(S-Amy)升高、肌酸激酶(CK)升高.结论 在100～500 mg剂量范围内单次口服羟戊基苯甲酸钾片耐受性良好.

Objectives: The emergence of colistin-resistant Klebsiella pneumoniae (CoRKp) is a serious public-health issue as colistin is the last line of defence against infections caused by multidrug-resistant Gram-negative bacteria. In this study, we generated a draft genome sequence for CoRKp strain P094-1 isolated from a sputum sample of an infected patient. Methods: Whole genomic DNA of strain P094-1 was sequenced using a PacBio sequencing platform. Gen-erated reads were de novo assembled using Hierarchical Genome Assembly Process (HGAP) v.3.0. Colistin resistance-related genes were predicted from the genome sequence and were validated experimentally. Results: The genome of strain P094-1 lacked a 20.3-kb region, including complete deletion of the mgrB gene. Molecular and genome sequencing-based analyses revealed that the observed colistin resistance of P094-1 could not be attributed to plasmid-borne genes mcr-1 to mcr-9 or to alteration of the pmr and pho operons (deletions, insertions or substitutions), but was conferred by an insertion sequence 1 (IS1)-induced total deletion of mgrB. Conclusion: This is the first reported whole-genome sequence of an unusual CoRKp isolate containing an IS1-induced deletion of mgrB. (c) 2021 Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Background: Vancomycin-resistant Enterococcus (VRE), as an important nosocomial pathogens, can be carried in gut for a long period and its colonization status associated with the subsequent infections. The aim of this study was to investigate the frequency of intestinal VRE colonization and identify the risk factors associated with VRE carriage in intensive care patients. Methods: We conducted a 4-week cross-sectional study at six hospitals in Beijing, China. Patients admitted to Intensive Care Units (ICUs) were screened for intestinal colonization of VRE every Tuesday morning. Rectal swabs were selectively cultured for VRE, then the identified strains were analyzed by PCR to detect the glycopeptide resistance gene and were characterized by MLST. Risk factors were recorded to assess their effect on VRE acquisition during ICUs stay. Results: Of 148 patients recruited, 46 (31.1%) were colonized with VRE, with the majority (n=42) being Enterococcus faecium . In total, 78.3% of the VRE were vanA positive and 15.2% vanM positive, while 6.5% undetected glycopeptide resistance gene. The predominant ST was ST78 (47.6%) followed by ST192 (14.3%), ST555 (9.5%), ST789 (9.5%), ST547 (4.8%), and ST922 (4.8%). Risk factors associated with VRE carriage were age of >65 years, a longer length of ICU stay, use of an endotracheal tube, and prior glycopeptides use. Conclusions: The overall incidence proportion of VRE colonization at ICUs was relatively high in Beijing, and clonal expansion and horizontal transmission of resistant genes were both found here. Routine screening is necessary to prevent the dissemination of VRE.

Background The purpose of this study was to investigate the safety, tolerability and pharmacokinetics of tetramethylpyrazine nitrone (TBN) in healthy Chinese volunteers. Methods A single-ascending-dose (SAD) study where 68 subjects were randomized to a single dose of placebo or TBN (50, 100, 200, 400, 700, 1,000, 1,400, or 1,800 mg) through IV infusion over 30 min. A multiple-ascending-dose (MAD) study where 24 subjects received TBN twice daily (with 12 hr interval) for total 6.5 days at doses of either 700 or 1,400 mg. Adverse events were recorded and pharmacokinetic samples were collected during the whole study period. Results No serious adverse events were found in the study. All of the observed adverse events, including increased white blood cell (4.4% subjects) and neutrophil counts (4.4% subjects), and decreased hemoglobin levels (4.2% subjects), were laboratory test abnormalities. All the adverse events were mild and tolerable, and returned to normal without any intervention. In the SAD study, linearC(max)values were observed in the dose interval of 50-1,800 mg. In the MAD study, the average steady-state concentrations (C-avg.ss) of TBN in the 700 and 1,400 mg dose group were 2,407 and 5,837 ng/ml, respectively. No drug accumulation was observed in this study. Conclusions TBN is well tolerated in healthy volunteers. LinearC(max)values were observed in the interval of 50-1,800 mg, and target exposures of TBN were achieved without accumulation after twice daily administration to subjects. (This study has been registered at . Identifier: ChiCTR1800016225 and ChiCTR1800019627.)

OBJECTIVES:To establish the epidemiological cut-off values (ECOFFs) for cefoselis against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Proteus mirabilis and Pseudomonas aeruginosa.METHODS:We collected 2288 non-repetitive clinical isolates from five laboratories throughout four cities in China. The cefoselis MICs and inhibition zone diameters for all isolates were established using the broth microdilution method and the disc diffusion method following EUCAST guidelines. MIC ECOFFs were determined by visual estimation and ECOFFinder software. Zone diameter ECOFFs were set if a high correlation of MICs and inhibition zone diameters was found by Pearson correlation. Zone diameter ECOFFs were finally determined by the visual estimate method.RESULTS:MICs of cefoselis were distributed from 0.008 to >256 mg/L for the four Enterobacterales species and from 0.25 to >256 mg/L for P. aeruginosa. MIC ECOFFs were 0.125 mg/L for E. coli, K. pneumoniae and P. mirabilis, 0.25 mg/L for E. cloacae and 32 mg/L for P. aeruginosa. A high correlation of MICs and zone diameters was observed for all Enterobacterales (|r| > 0.8, P < 0.001) and a relatively high correlation was found for P. aeruginosa (|r| = 0.71, P < 0.001). The zone diameter ECOFF was 24 mm for E. cloacae, E. coli and K. pneumoniae, 26 mm for P. mirabilis and 21 mm for P. aeruginosa.CONCLUSIONS:We determined MIC and zone diameter ECOFFs for cefoselis against four Enterobacterales species and P. aeruginosa. The establishment of ECOFFs for cefoselis provides clinicians with helpful guidance to differentiate WT and non-WT pathogens.