Microbiological external quality assurance program (MEQAP)--evaluation of results obtained in sanitary epidemiological laboratories in 2002

The aim of this study was to evaluate reliability of identification and determination of sensitivity to antibiotics and chemotherapeutics of some Gram positive cocci strains in 34 sanitary-epidemiological stations. All laboratories engaged in this study received 3 strains: S. aureus (S. aureus SC+ CF+, resistant to methicillin., or S. aureus SC - CF+, sensitive to methicillin), coagulase-negative staphylococci (S. epidermidis or S. haemolyticus or S. saprophyticus) and Enterococcus sp. (E. faecalis HLAR-positive or E. faecalis HLAR-negative or E. faecium or E. gallinarum). All these strains previously were identified in Department of Bacteriology of National Institute of Hygiene. Of the 68 staphylococci strains tested, 66 isolates were correctly identified. Among the 34 enterococcal strains studied the greatest difficulty in identification was caused by E. gallinarum strain--(8 out of 13 strains were incorrectly recognised). The determination of the sensitivity of the control strains to antibiotics and chemotherapeutic agents, generally was performed correctly in accordance with to the NCCLS and national recommendations. Some incorrect results of the antibiograms were caused by an erroneous interpretation of the zones of inhibition.     

Sensitivity to selected beta-lactam antibiotics of clinical strains of Escherichia coli and Klebsiella pneumoniae

The studies aimed at analysing the resistance to some beta-lactam antibiotics among E. coli and K. pneumoniae clinical isolates and at evaluating. The extended spectrum of beta-lactamases (ESBL) production in the isolates. The analysis included 137 E. coli strains and 52 K. pneumoniae strains, isolated from hospitalized patients and out-patients treated in the first trimester of 1998. The strains were identified using the ATB computer system. Antibiotic sensitivity of the isolates was determined by disc-diffusion tests. ESBL production capacity of E. coli and K. pneumoniae strains was estimated by double-disc and ATB BLSA tests. Most of the analysed E. coli strains were found to exhibit significant sensitivity to compound penicillin preparations containing beta-lactam inhibitor (Augmentin, Tazocin) and to the third generation cefalosporins, in contrast, K. pneumoniae strains much more frequently were resistant to the drugs. Among the obtained isolates, 3 (2.2%) E. coli strains and 21 (40.4%) K. pneumoniae strains produced ESBL but all the isolates proved sensitive to imipenem. In evaluation of ESBL production-detecting tests, the double-disc test was found to be more reliable than ATB BLSA test.     

2014—2016年大连地区血流感染肺炎克雷伯菌的耐药性特征分析

目的 分析肺炎克雷伯菌所致血流感染患者的科室分布及其病原菌耐药性特征,为指导临床合理应用抗菌药物,有效控制感染提供依据。方法 选择2014—2016年大连医科大学附属第一医院送检血液标本中分离得到的289株肺炎克雷伯菌,对其进行细菌鉴定、药敏试验及ESBL确认试验,分析肺炎克雷伯菌所致血流感染的科室分布特征及其病原菌耐药性变迁。结果 患者血液中肺炎克雷伯菌检出率以急诊科（24.91%）和ICU为最高（23.88%）。3年中肺炎克雷伯菌对碳青霉烯类抗生素和阿米卡星耐药率较低,均在20.00%左右。产ESBL肺炎克雷伯菌共135株,占46.71%,对常用抗生素的耐药率均显著高于非产ESBL菌株（P<0.01）。碳青霉烯类抗生素耐药菌株对常用抗生素耐药率均高于敏感菌株（P<0.01）,对四环素、复方新诺明和阿米卡星耐药率相对较低,分别为66.10%、66.10%、71.19%。结论 我院2014—2016年患者血液中肺炎克雷伯菌检出率以急诊科和ICU为最高。该菌对碳青霉烯类抗生素及阿米卡星的耐药率较低,碳青霉烯类抗生素耐药菌株对四环素、复方新诺明和阿米卡星尚有一定敏感性。     

Prevalence of extended-spectrum beta-lactamases produced by nosocomial isolates of Enterobacteriaceae in Trakya University Hospital,Turkey

The prevalence of extended-spectrum beta-lactamase (ESBL) production by 194 nosocomial isolates of Enterobacteriacea recovered from 1995 to 1999 was investigated. The ESBL production was determined by the double-disk synergy test and was confirmed by the E-test ESBL strip. Twenty-three isolates (21 Klebsiella pneumoniae, one Escherichia coli, one Providencia rettgeri) were found as ESBL-producers (11.8%). These isolates were also usually resistant to non-betalactam antibiotics. Most of them contained a beta-lactamase with a pI of 7.6. All the strains conjugally transferred their ESBLs to recipient E. coli. Contrary to others, ESBL-producing K. pneumoniae strains isolated in 1999 were resistant to ciprofloxacin, and had the identical plasmid profiles suggestive of an outbreak. Ciprofloxacin resistance in these strains could not be transferred. In conclusion, K. pneumoniae was the main ESBL-producing species among nosocomial isolates of Enterobacteriacae in our hospital.     

In vitro activity of three different antimicrobial agents against ESBL producing Escherichia coli and Klebsiella pneumoniae blood isolates

Extended spectrum beta-lactamases (ESBLs) usually associated with multiple drug resistance, including beta-lactam and non-beta-lactam antibiotics. This resistance can cause Limitation in the choice of drugs appropriate for using in clinical practice, especially in life-threatening infections. In this study we aimed to investigate in vitro activity of meropenem, ciprofloxacine and amikacin against ESBL-producing and non-producing blood isolates of Escherichia coli and Klebsiella pneumoniae strains. Fifty-eight E. coli (21 ESBL-producing, 37 non-ESBL producing) and 99 K. pneumoniae (54 ESBL-producing, 45 non-ESBL producing) strains were included in the study. The presence of ESBL was investigated by double disk synergy test and E-test methods. Antibiotic susceptibility test was done by microdilution method according to NCCLS guideline. In vitro susceptibilities of ESBL producing E. coli and K. pneumoniae strains were found as 100% for meropenem, 33.3% and 25.9% for ciprofloxacine, 94.5% and 83.3% for amikacin. It was observed that; meropenem was equally active agent in both ESBL-producing and non-producing strains, and its activity was not affected by ESBL production. Whereas amikacin activity was minimally affected and ciprofloxacine activity was markedly decreased by ESBL production. In conclusion, meropenem seems to be better choice of antibiotic should be used for ESBL positive life-threatening infections, because of remaining highest activity.     

Infectivity and resistance to antibiotics of bacterial strains isolated from patients hospitalised in intensive care units

The aim of this study was to evaluate the frequency of isolation and antimicrobial resistance testing of bacterial strains isolated from clinical specimens from patients hospitalized in three Intensive Care Units in Wroc?aw. The susceptibility of bacteria (107 strains) to selected antibiotics was determined. The results clearly show that non-fermentative rods were identified as the main agents causing pneumonia (58% of isolates). The second commonest pathogens were Gram-positive cocci (29%). The P. aeruginosa and E. cloacae strains were resistant to ampicillin, amoxicillin/clavulanate, cefuroxime and cefotaxime. All isolates of A. baumanii were susceptible only to imipenem. The rods of K. pneumoniae and E. coli were resistant to ampicillin, about 55% strains of both bacteria were sensitive to other antibiotics, except piperacillin/tazobactam, imipenem and ciprofloxacin. About 90% of methicillin resistant S. epidermidis strains were resistant to all antibiotics, except vancomycin (100% isolates were sensitive). ESBL were detected among E. cloace, K. pneumoniae and E. coli. We found P. aeruginosa rods producing MBL.     

社区与医院感染中肺炎克雷伯杆菌和大肠埃希菌耐药性分析

目的探讨社区和医院感染中肺炎克雷伯杆菌和大肠埃希菌产ESBLs的情况及耐药特性。方法采用体外扩散确证试验检测ESBLs,同时用Micro scan wat RA way-40系统全自动细菌鉴定/药敏分析仪及K-B琼脂扩散法进行细菌鉴定和体外药敏试验。结果社区感染标本中分离出肺炎克雷伯杆菌79株,产ESBLs20株,阳性率为25.3%,大肠埃希菌177株,产ESBLs27株,阳性率为15.3%;医院感染标本中分离出肺炎克雷伯杆菌82株,产ES-BLs33株,阳性率为40.2%,大肠埃希菌135株,产ESBLs42株,阳性率为31.1%,社区与医院感染菌株产ESBLs比较差异均有统计学意义(P均<0.05);ESBLs阳性菌株对多种抗生素耐药,其耐药性明显高于ESBLs阴性菌株。结论肺炎克雷伯杆菌和大肠埃希菌产ESBLs菌株在临床分离率较高,医院感染标本要显著高于社区感染标本,并且对多种抗生素具有高度耐药性,产ESBLs菌株耐药性显著高于不产ESBLs菌株,临床上应加强对ESBLs的控制,以防感染流行。     

Biological characteristics of Streptococcus pneumoniae strains isolated from children with pneumococcal diseases

The biological properties of 97 S. pneumoniae strains isolated from 92 children with purulent meningitides, meningoencephalitides, pneumonia and otitis, hospitalized at the Leningrad Research Institute of Childhood Infections, were studied. The data obtained in this investigation were indicative of the formation of atypical forms of pneumococci (R-forms, unbalanced growth forms and L-forms) in all clinical forms of pneumococcal infection in children. In purulent meningitides and meningoencephalitides serovars 1 and 6, in pneumonia serovars 1, 3 and 6 and in otitis serovars 6 and 19 played the leading role. The determination of sensitivity to antibiotics showed that the forms under study retained high sensitivity to a number of antibiotics. The appearance of strains resistant to benzylopenicillin was registered. (10%). The isolated strains either possessed low virulence or were avirulent in bioassay on white mice.     

Profiles of phenotype resistance to antibiotic other than β-lactams in Klebsiella pneumoniae ESBLs-producers, carrying blaSHV genes

Extended spectrum β-lactamases production is one of the most common mechanism of resistance to extended spectrum β-lactam antibiotics is increasing worldwide. Twenty five strains of Klebsiella pneumoniae isolated from clinical specimens were tested. Based on the phenotypic confirmatory test all these strains were defined as ESBL producers named ESBL(+). The plasmid DNA from each strains was used to investigate the presence of blaSHV genes responsible for extended spectrum β-lactamases production. Moreover, susceptibility of these strains to antibiotic other than β-lactams in was tested.     

The occurrence and characterisation of oxy-imino-beta-lactams resistant strains among Salmonella enterica subsp. enterica isolated in Poland

Extended-spectrum beta-lactamases (ESBLs) are enzymes manifesting considerable hydrolyzing activity on a wide variety of beta-lactam antibiotics including oxyiminocephalosporins and aztreonam. In the study reported here we investigated the types of ESBL produced by Salmonella enterica subsp. enterica strains isolated from clinical samples in the microbiological laboratories of sanitary-epidemiological units in Poland from 1999 to 2004. Among 239 ampicillin-resistant Salmonella enterica subsp. enterica strains isolated from clinical samples in the microbiological laboratories of sanitary-epidemiological units in Poland, 68 isolates of oximino-beta-lactams resistant of 6 serovars were found. There were 16 epidemiological unrelated strains (6 isolates of S. Enteritidis, 5 isolates of S. Thompson, 3 isolates of S. Typhimurium, one-fold isolate of S. Muenster and S. enterica 1,9,12:-:-) coming from different areas of country and 52 epidemiologically related isolates of S. Oranienburg, coming from a prolonged outbreak in an orphanage in Lód?. All the strains were identified as the ESBLs producers. The molecular analysis revealed that most of them expressed CTX-M-3 ESBL which is widely observed in Poland and additional enzyme TEM-1. All tested isolates of S. Thompson and one of three S. Typhimurium isolates were found to produce SHV-5 ESBL. This is the first report regarding the presence of SHV-5 in the genus Salmonella in Poland.     

Prevalence and antimicrobial resistance of extended-spectrum beta-lactamases-producing Escherichia coli and Klebsiella pneumoniae strains isolated in a university hospital in Split, Croatia.

The prevalence of Escherichia coli and Klebsiella pneumoniae that produce extended-spectrum b-lactamases (ESBL) was investigated in patients of a university hospital in Split, Croatia. Patients were grouped according to age (pediatric vs. adult), antibiotic type, and hospital ward. From Jan. 2001 to Dec. 2002, the susceptibility of E. coli and K. pneumoniae isolates to antimicrobials was tested. ESBL production was assayed using the double-disk synergy test. ESBL-producing E. coli and K. pneumoniae were detected in all sites of infection sampled. The percentages of ESBL-positive isolates were higher in the pediatric wards than in the adult wards. The antibiotics most commonly prescribed to patients in all hospital wards belonged to the third-generation cephalosporin group. Among ESBL producers, E. coli isolates were more resistant to aminoglycosides, but less resistant to ciprofloxacin and cotrimoxazole. Resistance of E. coli and K. pneumoniae to ciprofloxacin was exclusively found in isolates from adult patients. None of the isolates, regardless of ESBL production, was resistant to carbapenemes. In addition, the prevalence and antimicrobial resistance of ESBL-producing E. coli and K. pneumoniae isolates differed between pediatric and adult patients.     

连续12年产超广谱β-内酰胺酶肺炎克雷伯菌感染分布及耐药性分析

目的了解产超广谱β-内酰胺酶（ESBLs）肺炎克雷伯菌（KPN）的临床分布及耐药性,为临床合理选用抗菌药物提供依据。方法用常规方法,结合法国梅里埃公司的自动化细菌鉴定分析仪分离鉴定细菌;用K-B纸片扩散法进行药敏试验;用双纸片协同筛选法和酶抑制剂增强纸片法检测ESBLs。对中国医科大学附属盛京医院1999年1月至2010年12月期间临床分离的产ESBLs和非产ESBLs KPN菌株的临床分布及其耐药趋势进行回顾性分析。结果 KPN的ESBLs检出率分别从1999年的19.82%上升至2010年的49.34%;KPN主要分离于痰占52.4%,其次是血液占17.74%,主要来源于外科病区和新生儿病区;产ESBLs菌和非产ESBLs菌对阿米卡星、左氧氟沙星等非β-内酰胺酶类抗菌药物的耐药率均显著增高,差异具有统计学意义（P〈0.01）,对亚胺培南和美罗培南都保持高度敏感,耐药率均低于2%。结论 12年间ESBLs检出率总体呈上升趋势,产ESBLs肺炎克雷伯菌表达对包括非β-内酰胺类在内的抗菌药物多重耐药,对碳青霉烯类抗菌药物仍保持高度敏感性。     

Isolation rate of gram negative microflora and its sensitivity to antibiotics in hemoblastosis patients

A total of 67 patients with blood system diseases and infectious complications were examined. During the period of the examination 139 microorganisms were isolated. Of these gram negative microorganisms constituted 51%, gram positive microorganisms--34.8% and fungal flora--14.2%. Most frequently the following gram negative microorganisms were isolated from the patients: Pseudomonas sp. (including P. aeruginosa), Klebsiella pneumoniae, Escherichia coli, Haemophilus influenzae. All isolated microorganisms retained sensitivity to imipenem, with the exception of individual strains of Pseudomonas sp.; the latter exhibited sensitivity to amicacin and ceftazidim. Cefotaxime was active with respect to 75% of K. pneumoniae strains and all E. coli strains, ciprofloxacin was active with respect to 43% of E. coli strains, 80% of K. pneumoniae strains and 83.4% of Pseudomonas sp. strains, cefepim was active with respect to 85.7% of Pseudomonas sp. strains and all E. coli strains, ceftazidim was active with respect to all Pseudomonas sp. and E. coli strains. 75% of K. pneumoniae strains, 77.8% of Pseudomonas sp. strains and 86% of E. coli strains retained sensitivity to amicacin. 25% of K. pneumoniae strains required testing for ESBL production.     

Experience with epidemiologic studies of pyocyaneus infections. I. Feasibility of using serotypes and antibiotic resistance as a epidemiologic label for clinical strains]

The authors carried out serological typing of 98 Pseudomonas aeruginosa strains, isolated from patients of burn department of the Sklifosovsky First Aid Institute in January-July, 1974, and of 215 strains obtained from other sources; their sensitivity to 13 antibiotics was determined. Pseudomonas aeruginosa cultures isolated from the patients were typed with O-sera of 10 serological types. The presence of several hospital strains of Pseudomonas aeruginosa was found by means of serological typing; along with these there were revealed cultures of this causative agent sporadically appearing in the department. Sensitivity to some antibiotics could serve as an additional criterion for differentiation of Pseudomonas aeruginosa strains of the same serological type.     

Infectivity and resistance to antibiotics of uropathogenic gram-negative rods

The nature of bacterial isolates from children with clinically suspected urinary tract infections (UTI) was studied. The susceptibility of urinary pathogens to selected antibiotics was determined. The results clearly show that E. coli was identified as the main causative agent of UTI children (67% of isolates). The second commonest pathogen was P. mirabilis (10%). Over half E. coli isolates were resistant to amino-penicilins but almost all isolates (over 80%) were sensitive to antimicrobial agents combined with beta-lactamase inhibitors. We found significantly high percentage (32.5%) of ESBL strains among K. pneumoniae isolates.     

重症监护病房肺炎克雷伯菌ESBLs检测及耐药性分析

目的了解江山市人民医院重症监护病房肺炎克雷伯菌产超广谱β-内酰胺酶（ESBLs）的情况及其耐药性分析。方法收集2006年1月至2011年12月该院重症监护病房临床分离的肺炎克雷伯菌418株,采用VITEK-32全自动细菌鉴定仪;药物敏感试验采用K-B纸片扩散法,用双纸片协同试验进行ESBLs检测。采用聚合酶链式反应（PCR）扩增检测细菌产ESBLs的基因分型。结果 418株肺炎克雷伯菌主要来源于痰液标本和中段尿标本等,其中产ESBLs的肺炎克雷伯菌有111株。重症监护病房肺炎克雷伯菌年龄分布以71～80岁年龄组最高,而产ESBLs菌株则以51～60岁年龄组为最高,可达43.1%。产ESBLs菌株对一～三代头孢菌素、氯霉素、大多数氟喹诺酮类抗菌药物耐药率一直很高;对碳青霉烯类抗菌药物总体上有较高的敏感性,但耐药菌也在有所出现。PCR扩增检测ESBLs基因型,该院中CTX-M、SHV、TEM等均占较高比例,提示上述三种耐药基因型在本地区均有分布。结论医院重症监护病房临床分离的肺炎克雷伯菌产ESBLs的比例较高,尤其是泛耐药菌株的不断出现,给临床治疗带来了巨大难题,应引起高度重视,以预防重症监护病房感染的发生和暴发流行。     

The establishment of resistance phenotypes for bacteria isolated from outpatients in urine cultures

From 1911 outpatients, who addressed a Timi?oara private clinical laboratory, from January to December 2005, we collected 1,889 urine cultures, 431 being positive. Bacteria identification was generally done using morphological, cultural, biochemical characters and pathogenicity tests. Sensitivity testing to antimicrobial medical drugs was done by using the classical diffusion Kirby-Bauer method and the automatic analyzer Osiris, also. The main bacteria involved in the etiology of these infections were represented by Enterobacteriaceae, head of the list being Escherichia coli (81.21%), followed by Klebsiella pneumoniae (8.35%) and Proteus mirabilis (3.02%). We also isolated Gram positive cocci (in a much smaller proportion), mainly represented by Enterococcus faecalis (1.16%), Staphylococcus aureus (0.93%), Streptococcus agalactiae, and also Gram negative non-fermentative bacilli, such as Pseudomonas aeruginosa (0.93%) or Acinetobacter baumanii (0.23%). As soon as we performed the sensitivity tests, we divided them in resistance phenotypes: Most of the Enterobacteriaceae were integrated in the wild phenotype, followed by the penicillinase producing phenotype. An E. coli strain (0.29%) and 3 Klebsiella pneumoniae strains (8.33%) were integrated in the large spectrum, multidrug resistant, beta-lactamase producing phenotype, also associated with resistance to fluoroquinolones and aminoglycosides; Non-fermentative bacilli did not present special resistance problems, the four Pseudomonas aeruginosa strains were integrated in the wild phenotype (secreting induced chromosomal cephalosporinase). As for Staphylococcus aureus it was identified a strain having fluoroquinolone resistance, two strains secreting penicillinase and having a K (Nm) phenotype and a strain secreting penicillinase only. Antibiotic resistance represents a major concern for patients, physicians, healthcare managers, and policymakers. The use of antibiotics is closely linked with the development of acquired antibiotic resistance.     

社区老年人上呼吸道定植菌调查及药敏分析

调查社区老年人上呼吸道的定植菌情况,能够了解引起社区老年人呼吸道感染的危险因素,分析主要定植菌的药敏结果,指导社区老年人呼吸道感染的经验治疗。取社区老年人咽喉部拭子进行细菌分离培养及鉴定,调查呼吸道定植菌情况,并对主要定植菌进行药敏试验,细菌鉴定应用法国生物梅里埃公司的细菌鉴定仪VITEK2和API系统,药敏试验采用K-B纸片琼脂扩散法,结果统计应用WHONET5.4软件。对706例社区老年人上呼吸道标本进行分离培养,有274份标本生长了致病菌或条件致病菌,其中248份标本有一种细菌生长,26份标本生长2种细菌,总体阳性率为38.8%。共分离9种细菌,居首位的细菌是肺炎克雷伯菌151株,占21.4%,其次为副流感嗜血杆菌74株,占10.5%,第3位的是β-溶血链球菌31株,占4.4%。75株肺炎克雷伯菌的药敏结果显示全部为敏感株,从药敏表型分析具有较高的同源性。老年人群上呼吸道定植菌以革兰阴性杆菌尤其以肺炎克雷伯杆菌为主,并对常用抗菌药物有高度敏感性,一旦发生定植菌感染应选择合适的抗菌药物并给予恰当的治疗方案,防止细菌产生耐药性。     

Application of PCR ribotyping and tDNA-PCR for Klebsiella pneumoniae identification

PCR analysis of 16S-23S internal transcribed spacer (PCR ribotyping) and tRNA intergenic spacer (tDNA-PCR) were evaluated for their effectiveness in identification of clinical strains of Klebsiella pneumoniae and differentiation with related species. For this purpose both methods were applied to forty-three clinical isolates biochemically identified as K. pneumoniae subsp. pneumoniae isolated from patients clinical specimens attended at five hospitals in three Brazilian cities. References strains of K. pneumoniae subsp. pneumoniae, K. pneumoniae subsp. ozaenae, K. oxytoca, K. planticola and Enterobacter aerogenes were also analyzed. Both PCR methods showed specific patterns for each species. A conserved PCR ribotype pattern was observed for all clinical K. pneumoniae isolates, while differing from other related analyzed species. tDNA-PCR revealed five distinct patterns among the K. pneumoniae clinical isolates studied, demonstrating a predominant group with 90.6% of isolates presenting the same pattern of K. pneumoniae type strain. Both PCR-based methods were not able to differentiate K. pneumoniae subspecies. On the basis of the results obtained, both methods were efficient to differentiate the Klebsiella species analyzed, as well as E. aerogenes. Meanwhile tDNA-PCR revealed different tRNA arrangements in K. pneumoniae, suggesting intra-species heterogeneity of their genome organization, the polymorphism of the intergenic spacers between 16S and 23S rRNA genes appears to be highly conserved whithin K. pneumoniae clinical isolates, showing that PCR ribotyping can be an useful tool for identification of K. pneumoniae isolates.     

Evaluation of the usefulness of selected commercial systems for identification of Streptococcus species

The usefulness was assessed of three commercially available systems for rapid identification of streptococcal strains. The studied material comprised 68 strains of streptococci and enterococci (including 24 standard strains) belonging to serological groups: A (14 strains), B (10), C (11), D (10), F (3) and G (10), as well as 10 S. pneumoniae strains. The strains were isolated from throat, nasal, wound swabs, blood, pus of inpatients and throat and nasal swabs of outpatients. For the identification of streptococci 3 commercially available systems were used: API 20 STREP (bioMerieux, France), rapid ID 32 Strep (bioMerieux, France), Streptoplast PPL 18 (HTL, Poland). The determinations were done according to producer's instructions. The highest percent of correctly identified strains was obtained with the rapid ID 32 Strep--80.9%, with the API 20 STREP--76.4% strains were identified correctly and with the PPL 18--61.8%. The study showed that the API 20 STREP and rapid ID 32 STREP are suitable for the identification of streptococcal strains from groups: A, B, C, D, F and enterococci--group D. The proportions of correctly identified strains from these groups with the Streptoplast PPL 18 were lower than those determined with the bioMerieux systems. Using of three identification systems streptococci from group G and S. pneumoniae strains cannot be identified.