Aminoglycoside resistance in gramnegative pathogens of nosocomial infections in Russia]

The study of the mechanisms of aminoglycoside resistance in gramnegative pathogens of nosocomial infections in 14 hospitals of Russia showed that the basic mechanism was production of aminoglycoside modifying enzymes, mainly adenylyl transferase ANT(2"), acetyl transferases AAC(3)-V and ACC(6)-I, and phosphotransferases APH(3')-I and APH(3')-VI. In all the hospitals enzymes modifying gentamicin and tobramycin were wide spread while the resistance phenotypes to aminoglycosides were different in separate hospitals. Isepamycin proved to be the most active aminoglycoside. Recommendations for the use of antibiotics in hospital formulas and empiric therapy should be developed on the basis of the local specific features of the resistance in nosocomial pathogens to aminoglycosides.     

Etiology and microbiological diagnosis of nosocomial pneumonia in newborns]

A comparative analysis of the cases of ventilator-associated pneumonia (VAP) among premature infants in intensive care units and premature infant nurseries in 1994 (group I) and 1999 (group II) is presented. It was shown that the number of the cases of ventilator-associated pneumonia in the premature infants of group. I was 2,4 times higher than that in the group II (45.8 and 19.2 per cent respectively). A marked difference in the species pattern of the pathogens isolated from the endobronchial aspirate in 1994 and 1999 was observed. The species pattern of the isolates from the respiratory tract (Pseudomonas aeruginosa--40 per cent; Klebsiella pneumoniae--31 per cent; Staphylococcus epidermidis and Enterococcus--rare) showed that the pneumonia were nosocomial. The revealed similarity of the species patterns of the microflora in various parts of the respiratory tract and the throat posterior wall made it possible to consider the isolates of the throat posterior wall as a relative guide for confirming the etiological diagnosis of nosocomial pneumonia.     

肺炎克雷伯菌产碳青霉烯酶特性与耐药趋势研究

目的探讨临床分离的耐碳青霉烯类肺炎克雷伯菌(Klebsiella pneumoniae carbapenem-resistant,CRKP)的耐药机制及耐药趋势,为抗感染治疗提供依据。方法收集2008-2013年分离的CRKP 178株,分别运用VITEK-2 Compact全自动细菌分析仪和K-B纸片法检测菌株对药物的敏感性,改良Hodge试验确定是否产碳青霉烯酶以及EDTA抑制试验确定是否产金属酶,用PCR扩增和基因测序技术检测耐药基因。结果临床分离出肺炎克雷伯菌(Klebsiella pneumonia,Kpn)中CRKP的比例从2008年0.1%升至2013年2.2%,呈明显上升趋势;药敏结果显示,其对碳青霉烯类高度耐药外,对头孢曲松、氨曲南、环丙沙星等多种抗菌药物呈现出多重耐药;改良Hodge试验阳性170株(阳性率为95.5%);EDTA双纸片协同试验阳性1株(阳性率为0.6%)。PCR共检出150株携带KPC-2酶基因(blaKPC-2),阳性率为84.3%(150/178),1株肺炎克雷伯菌同时携带blaKPC-2和blaIMP-4,占0.6%(1/178)。结论台州医院分离的CRKP比例逐年升高,对多种抗菌药物高度耐药,产KPC-2型碳青霉烯酶是分离菌株对碳青霉烯类抗菌药物耐药主要原因。     

ICU患者铜绿假单胞菌获得性肺炎耐药研究

目的监测重症监护病房（ICU）铜绿假单胞菌（Pseudomonas aeruginosa,PA）的感染状况及耐药变迁,指导临床合理使用抗菌药物。方法对2003年至2007年间,我院ICU收治的患者下呼吸道分泌物进行培养及体外耐药试验。结果铜绿假单胞菌是ICU下呼吸道感染的主导致病菌且感染率呈逐年上升的趋势（46．3％-81．0％）,细菌对三代头孢、亚胺培南及氨基糖苷类药物的耐药性也呈逐年上升的趋势,并呈现多重耐药的特性。结论铜绿假单胞菌是ICU院内下呼吸道感染的常见病原菌,其多重耐药性及应引起高度重视。     

血液分离的肺炎克雷伯菌的患者疾病类型及耐药谱分析

目的 调查血液分离的肺炎克雷伯菌的耐药谱.方法 收集温州医学院附属第一医院2005年1月至2009年9月间血液分离的肺炎克雷伯菌,采用全自动微生物分析仪对肺炎克雷伯菌进行菌种鉴定和药敏试验,超广谱β-内酰胺酶的检测采用仪器法.舒普深和美洛培南的药敏试验采用K-B法.结果 80株分离自血液的肺炎克雷伯菌主要分离自患有肝胆疾病、血液系统疾病、呼吸系统疾病和神经系统疾病的患者,分别占20.0％、17.5％ 、15.0％和13.7％.80株肺炎克雷伯菌中,10株ESBLs阳性,阳性率为12.5％(10/80).除肺炎克雷伯菌对氨苄西林100％耐药外,对其他15种被测抗菌药物的耐药率全部低于20％,所有被测菌株对亚胺培南和美洛培南全部敏感,对其他9种抗菌药物的耐药率也低于10％.结论 血液分离的肺炎克雷伯菌主要来自患有肝胆疾病、血液系统疾病和神经系统疾病的患者.血液分离的肺炎克雷伯菌的ESBLs检出率非常低,且对常用抗菌药物的耐药率非常低.     

Genetic determinants of antibacterial resistance among nosocomial Escherichia coli, Klebsiella spp., and Enterobacter spp. isolates collected in Russia within 2003-2007

Nosocomial bacterial isolates collected within 2003-2004 (n=411) and 2005-2007 (n=422) were highly resistant to cephalosporins III-IV and antibacterials of other groups (aminoglycosides, fluoroquinolons, chloramphenicol, and co-trimoxazole). Genes encoding TEM, SHV, CTX-M, OXA-2, and AmpC types of beta-lactamases (BLs) in the E. coli, Klebsiella spp., and Enterobacter spp. isolates were detected using polymerase chain reaction (PCR). Prevalent CTX-M-type BLs were detected in 85% of the E. coli, 87% of the Klebsiella spp., and 38% of the Enterobacter spp. isolates of the first strain collection and in 94% of the E. coli, 91% of the Klebsiella spp., and 38% of the Enterobacter spp. isolates of the second one. Genes belonging to three subtypes of blacTx-M genes were identified: bla(CTX-M-1) (228 bla(CTX-M-15) and six bla(CTX-M-3) of the first strain collection; 275 bla(CTX-M-15), three bla(CTX-M-3), and one bla(CTX-M-22) of the second one), bla(CTX-M-2) (one bla(CTX-M-5) of the first strain collection and one bla(CTX-M-2) of the second one), bla(CTX-M-9) (17 bla(CTX-M-14) and one bla(CTX-M-9) of the first strain collection; seven bla(CTX-M-14) and one bla(CTX-M-9) of the second one). Three isolates of the first strain collection and one isolate of the second one carried two genes belonging to two different subtypes, i.e., bla(CTX-M-15) and bla(CTX-M-14) simultaneously. The bacterial isolates had high levels of associative resistance to ciprofloxacin, co-trimoxazole, gentamicin, amikacin, and chloramphenicol associated with the resistance gene cassettes aadA1, aadA2, aadA5, aadB, aacA4, aac(6')Ib; dfrA1, dfrA5, dfrA12, dfrA17, cmlA1, ereA2, and catB8 in the class 1 integrons and the resistance gene cassettes dfrA1, sat1, and aadA1 in the class 2 integrons.     

小儿呼吸道感染肺炎克雷伯杆菌耐药性和基因型研究

目的探讨临海地区小儿呼吸道感染肺炎克雷伯杆菌产超β-内酰胺酶（ESBLs和AmpC酶）的耐药性及耐药基因型分布情况。方法采用VITEK-60型全自动细菌鉴定仪鉴定细菌,按CLSI推荐的确证试验检测ESBLs和K-B纸片法测定药敏结果;采用头孢西丁纸片扩散法筛选产AmpC酶阳性菌株,采用PCR检测AmpC酶基因,并对产物进行测序分析基因型。结果113株肺炎克雷伯杆菌ESBLs和AmpC酶总检测率分别为29．20％和18．58％,其中单产ESBLs、单产AmpC酶和同产AmpC酶＋ESBLs检出率分别为23．01％、12．39％和6．19％;AmpC酶阳性菌株的耐药基因型：16株为DHA-1型,5株为ACT-1型。药敏试验：所分离的肺炎克雷伯杆菌对亚胺培南全部敏感,对喹诺酮类耐药率很低,对大多β-内酰胺类抗生素耐药率较高,并且产酶株的耐药性明显高于非产酶株,耐药现象在同产ES-BLS和AmpC酶菌株中更为严重。结论临海地区小儿呼吸道分离的肺炎克雷伯杆菌产ESBLs和AmpC酶检出率较高;AmpC酶以DHA-1基因型流行为主,产酶株呈现出高度多重耐药性。     

外排泵介导肺炎克雷伯菌耐药的研究进展

肺炎克雷伯菌(Klebsiella pneumoniae)是重要的条件致病菌,近年来肺炎克雷伯菌感染在医院内感染中所占的比率持续上升,耐药率也不断攀升,这给临床治疗带来极大的困难。肺炎克雷伯菌发生耐药的重要机制之一就是其细胞膜上存在的外排泵系统,它们将渗入细菌体内的药物不断泵出,导致菌体内的药物浓度过低,不足以发挥抗菌作用。本文主要针对外排泵介导肺炎克雷伯菌的耐药现状,外排泵的分子结构和基因调节,外排泵抑制剂以及传统中药在耐药菌治疗方面的应用等做系统性梳理,以期为临床治疗耐药肺炎克雷伯菌提供一些新思路。     

血流感染碳青霉烯类耐药肺炎克雷伯菌的耐药分析及同源性研究

本研究旨在探讨血流感染碳青霉烯类耐药肺炎克雷伯菌(carbapenem-resistant Klebsiella pneumonia, CRKP)的耐药特点、分子分型特征和菌株同源性,为CRKP感染的临床诊治和预防控制提供理论参考。收集2015年4月至2018年3月期间就诊于上海市某三甲医院患者血标本分离的肺炎克雷伯菌(KP)非重复菌株,采用VITEK 2 Compact全自动细菌鉴定仪鉴定细菌并进行药物敏感性试验,共获得51株CRKP。对CRKP菌株使用纸片扩散法或琼脂稀释法进行15种抗菌药物的敏感性试验;采用聚合酶链式反应(polymerase chain reaction,PCR)检测碳青霉烯酶基因型;通过脉冲场凝胶电泳和多位点序列分型(MLST)技术分析菌株同源性。结果显示,51株CRKP对检测的15种临床常用抗菌药物呈广泛耐药,对其中的哌拉西林、头孢唑啉、头孢吡肟、头孢噻肟、头孢呋辛、头孢他啶、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦和环丙沙星耐药率为100%;对阿米卡星、庆大霉素和复方新诺明的耐药率较高,分别为76.5%、90.2%和62.8%;对替加环素耐药率较低,为3.9%。51株CRKP均检测出blaKPC基因,经测序鉴定为blaKPC-2基因,提示产KPC-2是CRKP对碳青霉烯类耐药的主要机制。MLST检测到4种ST型别,以ST11型为主,共 43株(84.3%),另有ST15型6株(11.8%),ST4845型1株及1株新分型。51株CRKP的PFGE图谱相似性系数在62.9%～100%,可分为19个簇(A-S簇),每簇分别包含1～12个菌株。其中A簇(13.7%)和G簇(23.5%)包含的菌株相对较多,且MLST分型均为ST11型,为优势簇。G簇包含7个型别,G4型为主要克隆菌株。 ST11型为CRKP的主要型别,PFGE分析表明该院存在菌株的克隆传播,应规范抗菌药物使用,同时加强细菌耐药性监测和医院内感染的防控工作。     

Prevalence of nosocomial infections in selected hospitals

A point prevalence survey of NI in 10 hospitals has been carried out with the aim to obtain more valid results about their occurrence and to raise the interest of clinicians in this problem. Altogether data on 5,553 hospitalized patients have been evaluated. An epidemiologist along with a clinician jointly found a total 365 of NI in 344 patients a point prevalence 6.6%. The prevalence ranged between 3.6 and 10.5% for different hospitals. The highest NI prevalence was found in surgical wards (urology 19.6%, surgery 12.2%). Undesirably high prevalence of NI was observed in paediatrics (mainly diarrhoeal diseases) and neonatal (conjunctivitis) wards. Infections of the upper respiratory tract were most frequently followed by surgical wound infections and infections of the urinary tract. The occurrence of NI of surgical wounds, urinary tract infections and infections of skin was increasing, while the occurrence of infections of gastrointestinal tract and of the eye was decreasing with age. Gram-negative bacteria were more frequently isolated than Gram-positive bacteria (2:1).     

2011-2013年重庆地区儿童感染肺炎克雷伯菌临床分布及耐药性分析

目的了解重庆地区儿童2011-2013年肺炎克雷伯菌的临床分布特征及耐药性,为合理应用抗菌药物和预防控制医院交叉感染提供依据。方法分析我院2011-2013年临床标本分离出的5 500株肺炎克雷伯菌对18种抗菌药物的耐药性,采用BD Phoenix 100 MIC法结合K-B纸片扩散法进行药敏试验,按美国临床实验室标准化委员会(CLSI)标准判断结果。结果共分离肺炎克雷伯菌5 500株,以痰标本多见,占84.9%(4 668株);其在不同病房中以新生儿科病房分布最高,其次为呼吸病房,分别为30.4%和23.0%。肺炎克雷伯菌对阿米卡星的耐药率最低,仅为2.5%,美罗培南、左旋氧氟沙星、亚胺硫霉素耐药率分别为3.5%、3.6%、3.8%。2011-2013年肺炎克雷伯菌对亚胺硫霉素、左旋氧氟沙星、阿米卡星、环丙沙星、氯霉素、美罗培南的耐药率无明显改变(P0.05),其余受试药物的耐药率均有明显改变(P0.05)。超广谱β-内酰胺酶(ESBLs)检出率为33.2%(1 828株),2011-2013年ESBLs检出率有明显改变(P0.0001)。结论肺炎克雷伯菌的耐药性呈上升趋势,新生儿科是本院预防控制的重点科室。     

The spread of Klebsiella in obstetrical hospitals and the biological properties of the isolated strains]

Examination of 278 newborn infants, parturients, and medical personnel in two maternity hospitals revealed a high level of Klebsiella colonization of all examined biotopes of infants (the nasal cavity in up to 36.5% of cases) and the skin of the mammary glands of nursing mothers (in 36.2% of cases). In the intestine and the nasal cavity of parturient women and medical personnel Klebsiella could be detected 3-10 times more often than in the same biotopes of nonhospitalized pregnant women. From 254 objects of the hospital environment Klebsiella were isolated in 9.05% of cases. The possibility of the transmission of Klebsiella in hospitals by patients with inflammatory processes in their genitals were established. The diversity of the serological picture of strains of most K-serovars and a short period of their isolation were shown. In one hospital serovar K10 with some features of a "hospital" strain was isolated. The strains under study were sensitive to aminoglycosides, cephamesine, chlorhexidine, but resistant to semisynthetic penicillins and chloramine.     

2008-2012年484株肺炎克雷伯菌耐药性分析及耐药机制的初步研究

目的回顾性分析近五年来医院住院及门诊病原菌感染患者中肺炎克雷伯菌的分离趋势,探讨其对常规抗菌药物的耐药性变迁和相关耐药机制。方法采用法国梅里埃公司的Vitek-2 Compact全自动微生物分析仪进行细菌鉴定及药敏试验,部分菌株采用微量生化管鉴定,部分药敏试验采用琼脂扩散法（KB）,药敏结果判读按照美国临床和实验室标准化协会（CLSI）制定的标准判读,纸片法表型确证试验检测超广谱β-内酰胺酶（ESBLs）,改良Hodge试验检测碳青霉烯酶表型,EDTA双纸片法检测金属酶表型。结果五年间484株肺炎克雷伯菌部分药物耐药率正逐年上升,其常见药物平均耐药率如下：阿米卡星（3.0%）,复方新诺明（31.1%）,头孢三嗪（14.5%）,环丙沙星（18.7%）,氯霉素（21.6%）,特治星（6.3%）,头孢他啶（22.0%）,头孢噻肟（23.6%）,舒普深（4.2%）,呋喃妥英（26.9%）,美罗培南（2.1%）,ESBLs阳性99株（20.4%）,改良Hodge试验检测碳青霉烯酶表型阳性5株,EDTA双纸片法检测金属酶表型阳性2株。结论部分药物耐药率逐年上升的有复方新诺明、环丙沙星、头孢他啶、头孢噻肟;耐药率较低的有美罗培南、阿米卡星、舒普深、特治星、头孢三嗪。应加强细菌耐药性监测,以及耐碳青霉烯酶筛查试验,为临床提供用药参考。     

Comparison of linezolid and vancomycin in nosocomial pneumonia: results of the multicenter double-blind study]

The results of multicenter, randomized, double-blind comparative study of linezolid and vancomycin efficacy, safety and tolerability in the treatment of nosocomial pneumonia are presented. The trial was performed on 69 patients. Clinical efficacy of linezolid was 83 per cent, of vancomycin--79 per cent. Bacteriological effect (pathogen eradication) was 83 per cent for linezolid group and 86 per cent for vancomycin group. During the study good clinical tolerability of linezolid was demonstrated along with lower side effects incidence and shortened recovery period when compared to vancomycin.     

Measures of prophylaxis of nosocomial infections in somatic hospitals

Data are presented on the complex of measures for the prophylaxis of infections at the obstetrical and surgical clinics; also information on the efficacy of new disinfectants made in the USSR for the disinfection of objects of external environment, hands of medical personnel and air in somatic hospitals is given.     

The resistance plasmid of Klebsiella pneumoniae that controls its cytotoxic activity]

R-plasmid (40 MD) isolated from K. pneumoniae hospital strain makes Escherichia coli strain J62 capable of inducing a cytotoxic effect which can be detected in Hep-2 cell culture. In contrast to the initial E. coli strain J62 producing no changes in the monolayer, E. coli J62 cells containing P-plasmid induced pronounced cytotoxic changes and a sharp increase in the number of nonviable Hep-2 cells by hour 24 of interaction.     

Magnetic resonance imaging of Klebsiella pneumoniae-induced pneumonia in mice

In vivo imaging of small animals is a rapidly developing field. However, the potential of global imaging of infectious processes in animal models remains poorly explored. We used magnetic resonance imaging (MRI) to follow the development and regression of inflammatory lesions caused by infection by Klebsiella pneumoniae in mouse lungs. A virulent strain caused an intense inflammation within 2 days in the whole lungs, while an avirulent strain did not show significant changes. Mice infected with the virulent strain and subsequently treated with antibiotics presented a severe inflammation localized mainly in the left lung that disappeared after a week. The lesions observed by MRI correlated with the damage seen by histological analysis and a 3D representation of the tissue allowed better visualization of the development and healing of inflammatory lesions. MRI thus represents a powerful technique to study in vivo the interactions between a pathogen and its host in real time.     

Antibiotic resistance of Staphylococcus aureus strains isolated in two different Warsaw hospitals]

S. aureus strains isolated in the same period from different specimens obtained from patients of two different hospitals were compared. The significant differences were observed in the frequency of resistance determinants between strains of these hospitals. The most important was the difference in the prevalence of MRSA. In the first hospital the percentage of MRSA was 40% whereas in the second one only 20%. The resistance to the other antibiotics was also compared, and independently from the compared group: MRSA, MSSA or all, the prevalence of resistance determinants was higher in the first hospital than in the second. Although the frequencies of MRSA in both investigated hospitals were relatively high comparing to the other European countries and in the first hospital even alarming, isolated MRSA strains are less resistant to other antibiotics than MRSA in other countries.