新生儿血培养中病原菌的分布及耐药性分析

目的监测新生儿血流感染常见病原菌分布特征及其耐药性，指导新生儿感染的预防和控制。方法采用法国生物梅里埃ATB Expression鉴定及药敏仪进行细菌鉴定和药敏试验。结果372株病原菌中居前3位的依次为凝固酶阴性葡萄球菌（77．7％）、大肠埃希菌（4．8％）、金黄色葡萄球菌（4．0％）。药敏显示MRS菌株对β－内酰胺类抗生素100％耐药，对万古霉素100％敏感。G－杆菌对亚胺培南100％敏感。结论MRS菌株已成为新生儿血流感染的主要病原菌，应严格执行消毒隔离制度，根据新生儿生理特点及药敏试验结果合理用药。     

血培养常见菌株的分布及金黄色葡萄球菌耐药性的分析

目的调查同济医院2006年1月至2008年12月血培养中常见非重复分离菌株的构成;分析金黄色葡萄球菌对常用抗菌药物的耐药性。方法采用WHONET5．4软件分析连续3年血培养中的非重复分离菌株的分布;采用K-B纸片法测定金黄色葡萄球菌对常用抗菌药物的敏感性。结果2006年1月至2008年12月共分离细菌1336株,其中革兰阳性球菌占58．5％（781／1336）、革兰阴性杆菌占37．2％（497／1336）、真菌占4．27％（57／1336）。分离的前10位菌株依次为凝固酶阴性葡萄球菌（CNS,40．42％）、大肠埃希菌（13．47％）、肠球菌属（5．54％）、克雷伯菌属（4．94％）、金黄色葡萄球菌（4．34％）、草绿链球菌（4．34％）、真菌（4．27％）、沙门菌属（3．59％）、铜绿假单胞菌（3．29％）、嗜麦芽窄食单胞菌（3．14％）。金黄色葡萄球菌共58株,其中甲氧西林耐药金黄色葡萄球菌（methicillinresistantStaphylococcusoltl-eus。MRSA）占44．8％（26／58）。MRSA对头孢菌素类、氨苄西林／舒巴坦、红霉素、克林霉素、复方新诺明、庆大霉素和左氧氟沙星、磷霉素、利福平耐药率明显高于甲氧西林敏感的金黄色葡萄球菌（methicillin—susceptibleStaphylococcuso,uFeus,MSSA）,且差异具有统计学意义（P〈0．001）。未发现对万古霉素和替考拉宁不敏感的菌株。结论本院血培养分离株中,凝固酶阴性葡萄球菌仍占据第一位。金黄色葡萄球菌占分离菌株第五位,其中MRSA检出率较高,且耐药性严重。MRSA病区的分布及耐药谱分析提示可能存在MRSA的克隆传播。     

新生儿败血症细菌耐药性与敏感性分析

目的　及早有效地干预治疗新生儿败血症 ,减少其死亡 .方法　分析了新生儿败血症的有关临床及致病菌的耐药性和敏感性资料 .结果　 32例新生儿败血症中死亡 5例 (15 .6 % ) ,医院感染 2例 (6 .2 5 % ) .严重的新生儿败血症有严重原发疾病 ,主要由革兰氏阴性菌引起 .主要的优势菌群有凝固酶阴性葡萄球菌、克雷伯菌、大肠埃希氏菌、铜绿假单胞菌 .结论　凝固酶阴性葡萄球菌是新生儿败血症最主要的病原菌 ,加强对复合菌或革兰氏阴性杆菌引起败血症的监测、治疗 ,严格执行各种治疗原则 ,预防医院感染败血症的发生 .     

新生儿败血症细菌耐药性与敏感性分析

目的及早有效地干预治疗新生儿败血症,减少其死亡.方法分析了新生儿败血症的有关临床及致病菌的耐药性和敏感性资料.结果 32例新生儿败血症中死亡5例(15.6%),医院感染2例(6.25%).严重的新生儿败血症有严重原发疾病,主要由革兰氏阴性菌引起.主要的优势菌群有凝固酶阴性葡萄球菌、克雷伯菌、大肠埃希氏菌、铜绿假单胞菌.结论凝固酶阴性葡萄球菌是新生儿败血症最主要的病原菌,加强对复合菌或革兰氏阴性杆菌引起败血症的监测、治疗,严格执行各种治疗原则,预防医院感染败血症的发生.     

1145例新生儿需氧血培养结果分析

目的了解近年来住院新生儿需氧血培养病原菌种类.方法用BACTEC-9120全自动血培养仪对1145例中新生儿需氧血培养进行检测,对结果进行比较分析.结果 1145例共检出病原菌125株(10.9%),其中革兰氏阳性菌占9.4%,革兰氏阴性菌占1.5%.葡萄球菌108株,肠杆菌科细菌11株,革兰氏阴性非发酵菌6株.男女及年龄段无差异.结论凝固酶阴性的葡萄球菌检出率最高.早期新生儿感染病原菌种类较多,分布较广.     

2013-2015年鲍曼不动杆菌感染分布特征与耐药性变迁

目的：了解徐医附院2013—2015年临床分离鲍曼不动杆菌的临床分布特征及对抗菌药物的耐药性变迁,为临床合理使用抗菌药物提供依据。方法：对2013—2015年徐医大附院收集的所有鲍曼不动杆菌临床数据进行分析。结果：2013—2015年共收集鲍曼不动杆菌1664株,其中在临床ICU科室检出率最高,占58.2%。临床分离的鲍曼不动杆菌耐药严重,其中对碳青霉烯类抗菌药物的耐药率已高达73.0%以上。对其他β内酰胺类、头孢菌素类等抗菌药物的耐药率总体维持在70.0%~80.0%之间。结论：鲍曼不动杆菌感染在ICU最为严重,且对常规抗生素耐药率普遍较高。应加强鲍曼不动杆菌耐药监测,以提高临床对感染性疾病的诊治疗效。     

1145例新生儿需氧血培养结果分析

目的：了解近年来住院新生儿需氧血培养病原菌种类．方法：用BACTEC——9120全自动血培养仪对1145例中新生儿需氧血培养进行检测，对结果进行比较分析．结果：1145例共检出病原菌125株(10．9％)，其中革兰氏阳性菌占9．4％，革兰氏阴性菌占1．5％．葡萄球菌108株，肠杆菌科细菌11株，革兰氏阴性非发酵菌6株．男女及年龄段无差异．结论：凝固酶阴性的葡萄球菌检出率最高．早期新生儿感染病原菌种类较多，分布较广．     

血培养阳性病原菌的临床分布及耐药性分析

目的了解血培养中分离菌株的构成比及耐药情况。方法采用回顾性分析．对BacT／Alert3D全自动快速血液细菌培养系统培养的2138份血液标本进行检测，分离所得菌株用VITTEK32全自动微生物分析／药敏系统进行鉴定和药敏试验。结果分离152株阳性菌株。阳性率为13．97％。革兰阴性杆菌103株，占67．3％；革兰阳球菌34株，占22．2％；真菌15株，占9．8％。血中产超广谱B一内酰酶（ESBLs）的大肠埃希菌和肺炎克雷伯菌检出率分别为22．5％和32．5％。在凝固酶阴性葡萄球菌和金黄色葡萄球菌中MRSCN和MRSA分别是85．7％和55．0％。结论目前深圳市第二人民医院菌血症仍以革兰阴性杆菌为主，对血培养中分离的菌株进行耐药性监测很有必要，及时了解血培养结果对临床有针对性的抗菌治疗可提供科学依据．提高治愈率，降低病死率。     

临床分离4364株细菌的分布特征和耐药性变迁分析

目的了解2003—2005年分离的4364株细菌的分布特征及耐药性变迁，为合理使用抗菌药物提供依据。方法大多数分离细菌的鉴定和药敏试验利用BD Phoenix仪，少数利用手工鉴定和K-B法药敏试验。数据分析用WHONET5．0软件。结果葡萄球菌对万古霉素和替考拉宁的敏感率一直为100％，对其他抗菌药物的耐药率大多逐年上升，甲氧西林耐药率也逐年上升，金黄色葡萄球菌从40．8％上升到61．6％，表皮葡萄球菌从69．7％上升到79．8％。G^-杆菌合计，大多数抗菌药物的耐药率逐年升高，耐药率一直低于30％的为美洛培南、亚安培南、头孢哌酮／舒巴坦、哌拉西林-他唑巴坦和头孢他啶。大肠埃希菌和肺炎克雷伯菌体外产ESBLs的检出率一直居高不下，为29．5％～45．5％。结论本院肠杆菌科产ESBLs比例、葡萄球菌甲氧西林耐药率和非发酵菌碳青霉烯类耐药率均较高，应加强抗菌药物的合理使用和采取有效的隔离措施以降低耐药率及多重耐药菌的扩散。     

医院感染患者痰液中分离细菌的分布特征和耐药性变迁分析

目的了解2003—2005年医院感染患者痰液中分离细菌的分布特征和耐药性，为合理使用抗菌药物提供依据。方法大多数分离细菌的鉴定和药敏试验利用BD Phoenix仪，少数利用手工鉴定和K—B法药敏试验。数据分析用WHONET5．0软件。结果医院感染患者痰液中最常见的为铜绿假单胞菌、肺炎克雷伯菌、金黄色葡萄球菌和表皮葡萄球菌。痰液中分离的G-杆菌合计，耐药率低于40％的为美洛培南、亚安培南、头孢哌酮／舒巴坦、哌拉西林-他唑巴坦、头孢他啶和头孢吡肟。大肠埃希菌和肺炎克雷伯菌产超广谱β-内酰胺酶（ESBLa）的检出率为45．2％-62．5％和36．7％-52．3％。葡萄球菌对多肽类抗菌药物万古霉素的敏感率一直为100％，对其他抗菌药物的耐药率均大于30％。金黄色葡萄球菌和表皮葡萄球菌甲氧西林耐药性居高不下，分别为69．8％-72．0％、77．3％-87．1％。非发酵菌碳青霉烯类耐药率不断升高，铜绿假单胞菌对美洛培南和亚安培南耐药率已分别高达30．5％和49．4％。结论医院感染患者痰液中肠杆菌科产ESBLa比例、葡萄球菌甲氧西林耐药率和非发酵菌碳青霉烯类耐药率均较高，应加强抗菌药物的合理使用和采取有效的隔离措施以降低耐药率及多重耐药菌的扩散。     

Prevalence and antimicrobial resistance pattern of multidrug-resistant enterococci isolated from clinical specimens

Purpose: Vancomycin-resistant enterococci (VRE) pose an emerging problem in hospitals worldwide. The present study was undertaken to determine the occurrence, species prevalence, antibacterial resistance, and phenotypic and genetic characteristics of VRE isolated in Riyadh hospitals, KSA. Materials and Methods: Two hundred and six isolates of enterococcal species were obtained from clinical samples. The antibiotic susceptibility of isolates and minimum inhibitory concentration (MIC) tests for vancomycin and teicoplanin were determined. Molecular typing of VRE isolates was carried out by using pulsed field gel electrophoresis (PFGE) and the resistance genotype was determined by polymerase chain reaction (PCR). Results: VRE accounted for 3.9% of the isolates and were detected mostly in urine, wound and blood specimens isolated from ICU, internal medicine and surgical wards. All strains were identified to species level and were found to consist of E. faecalis (69.2%), E. faecium (11.3%), E. avium (2.1%), E. hirae (0.8%), E. casseliflavus (1.3%) and E. gallinarum (1.3%) species. According to the susceptibility data obtained, 8 (3.9%) out of 206 isolates were found to be VRE (MICs > 32 µg/ml). The vanA, vanB and vanC gene fragments of E. faecalis, E. faecium and E. gallinarum were amplified from isolates and were detected. PFGE patterns of the VRE isolates revealed homogenous patterns with dominant clone suggesting that the strains intrinsic resistance is independent. Conclusions: This study shows an emergence of VRE along with increased rate of multidrug-resistant enterococci in the area of the study. Regular surveillance of antimicrobial susceptibilities should be done regularly and the risk factors should be determined.     

Rapid molecular tests for detection of antimicrobial resistance determinants in Gram-negative organisms from positive blood cultures: a systematic review and meta-analysis

BackgroundTimely detection of antimicrobial (cephalosporin/carbapenem) resistance (AMR) determinants is crucial to the clinical management of bloodstream infections caused by Gram-negative bacteria (GNB).ObjectivesTo review and meta-analyse the evidence for using commercially available molecular tests for the direct detection of AMR determinants in GNB-positive blood cultures (PBCs).Data sourcesPubMed, Scopus and ISI Web of Knowledge.Study eligibility criteriaClinical studies evaluating the performance of two major commercial systems, namely the Verigene® and FilmArray® systems, for rapid testing of GNB-PBCs, in comparison with the phenotypic or genotypic methods performed on GNB-PBC isolates.MethodsLiterature search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria and, for meta-analysis of sensitivity and specificity of both systems, bivariate random-effects model.ResultsTwenty studies were identified (3310 isolates) from 2006 to 2019. Nine studies were conducted in East Asia. In 15 studies using phenotypic comparators (1930 isolates), 1014 (52.5%) isolates were Escherichia coli, and 287 (14.9%) of all the isolates displayed AMR phenotypes. In five studies using genotypic comparators (1380 isolates), 585 (42.4%) were E. coli, and 100 (7.2%) of all the isolates displayed AMR genotypes. Pooled sensitivity and specificity estimates for detection of AMR determinants by the Verigene (i.e. CTX-M, IMP, KPC, NDM, OXA and VIM) and/or FilmArray (i.e. KPC) systems were 85.3% (95% CI 79.9%–89.4%) and 99.1% (95% CI 98.2%–99.5%), respectively, across the 15 studies, and 95.5% (95% CI 89.2%–98.2%) and 99.7% (95% CI 99.1%–99.9%), respectively, across the five studies.ConclusionsOur findings show that the Verigene and FilmArray systems may be a valid adjunct to the conventional microbiology (phenotypic or genotypic) methods used to identify AMR in GNBs. The FilmArray system detects only one AMR genotype, namely KPC, limiting its use. Both Verigene and FilmArray systems can miss important cephalosporin/carbapenem resistance phenotypes in a minority of cases. However, the sensitivity and specificity of both systems render them valuable clinical tools in timely identification of resistant isolates. Further studies will establish the prominence of such rapid diagnostics as standard of care in individuals with bloodstream infections.     

Enterococcus faecium isolated from bone marrow transplant patients in Tunisia: high prevalence of antimicrobial resistance and low pathogenic power

Objectives

Investigation of the occurrence and antibiotic susceptibility of Enterococcus faecium isolates, collected during four years from neutropenic patients at the Tunisian bone marrow transplantation centre.

Materials and methods

E. faecium strains were identified by conventional methods and by the Api20 Strep (Bio-Mérieux, France). Antibiotic susceptibility was determined by the disk diffusion method on Mueller-Hinton agar and interpreted as recommended by CA-SFM. MICs of ampicillin, vancomycin, and teicoplanin were determined by E-test method.

Results

Two hundred and thirty five E. faecium isolates were recovered from stool cultures or rectal swabs (229), throat (three), urine (two), and pus of wound (one). None was responsible for bacteraemia. Ampicillin resistance, without production of β-lactamase, was observed in 43.8% of isolates. All the isolates were susceptible to glycopeptides. High rates of resistance were observed: high-level resistance (HLR) to gentamicin (33.6%), HLR to kanamycin (55.7%), HLR to streptomycin (47.6%), erythromycin (86.4%), ciprofloxacin (78.7%), rifampicin (85%), and tetracycline (43%). Strains with HLR to gentamicin were significantly more resistant to ampicillin and streptomycin. Multiple drug resistance was observed in most isolates.

Conclusion

These findings demonstrated the low pathogenic power of E. faecium in our patients, and the high frequencies of resistance to ampicillin and aminoglycosides. In the absence of glycopeptide-resistance, vancomycin remains an alternative treatment against multidrug resistant strains.     

Global epidemiology of antimicrobial resistance in commensal Neisseria species: A systematic review

BackgroundCommensal Neisseria species (spp). represent an important reservoir of antimicrobial resistance genes for pathogenic Neisseria spp. In this systematic review, we aimed to assess the antimicrobial susceptibility of commensal Neisseria spp. and how this has evolved over time. We also aimed to assess if commensal Neisseria spp. showed intrinsic resistance to four antimicrobials - penicillin, azithromycin, ceftriaxone and ciprofloxacin.MethodsPubmed and Google Scholar were searched following the PRISMA guidelines. Articles reporting MICs of commensal Neisseria spp. were included according to inclusion/exclusion criteria, and the quality of the articles was assessed using a pre-designed tool. Individual and summary measures of penicillin, azithromycin, ceftriaxone and ciprofloxacin MICs were collected. Additional data was sought to perform a comparison between the MICs of pathogenic and commensal Neisseria spp.ResultsA total of 15 studies met our criteria.We found no evidence of intrinsic AMR in commensal Neisseria spp. We did find evidence of an increasing trend in MICs of commensal Neisseria spp. over time for all antimicrobials assessed. These findings were similar in various countries. Eight additional studies were included to compare pathogenic and commensal Neisseria spp.ConclusionThe MICs of commensal Neisseria spp. appear to be increasing in multiple countries. Surveillance of MICs in commensals could be used as an early warning system for antimicrobial resistance emergence in pathogens. Our findings underline the need for antibiotic stewardship interventions, particularly in populations with high antimicrobial consumption.     

Changing aetiology,clinical features,antimicrobial resistance,and outcomes of bloodstream infection in neutropenic cancer patients

Recent changes in the management of patients with haematological malignancies might have influenced the aetiology, characteristics, antimicrobial resistance and outcomes of bloodstream infection (BSI) during neutropenia. We compared 272 episodes of BSI in adult neutropenic patients with cancer prospectively collected from January 1991 to December 1996 (first period), when quinolone prophylaxis was used, with 283 episodes recorded from January 2006 to March 2010 (second period), when antibacterial prophylaxis was stopped. Patients in the second period were significantly older and were more likely to have graft-versus-host disease and a urinary catheter in place, whereas the presence of a central venous catheter, parenteral nutrition, corticosteroids and antifungal and quinolone prophylaxis, were more frequent in the first period. More patients in the first period had mucositis and soft-tissue infection as the origin of BSI, but an endogenous source was more common during the second. Gram-positive BSI was more frequent in the first period (64% versus 41%; p <0.001), mainly due to coagulase-negative staphylococci and viridans group streptococci. In the second period gram-negative BSI increased (28% versus 49%; p <0.001), quinolone susceptibilities were recovered, but multidrug-resistant gram-negative BSI also increased (1% versus 6%; p <0.001). Although patients in the second period were more likely to need admission to the intensive-care unit, overall case-fatality rate was similar in the two periods (19% versus 15%). The aetiology of BSI in neutropenic patients with cancer has shifted from gram-positive to gram-negative organisms. Multidrug resistance among gram-negative bacilli is emerging as a therapeutic challenge. Overall case-fatality rate remains high.     

肝炎肝硬化患者合并败血症病原学及耐药分析

目的总结肝炎肝硬化患者合并败血症的病原菌分布及耐药情况。方法回顾分析33例肝炎肝硬化合并败血症患者的肝功能指标、凝血指标、外周血象及血培养结果,分析导致败血症的原因。结果 33例患者合并败血症与其肝硬化严重程度相关,致病菌中革兰阳性菌7株（占21.0%）,革兰阴性菌26株（占79.0%）。革兰阳性菌株中肺炎链球菌和金黄色葡萄球菌对常用抗菌素普遍耐药,革兰阴性菌株中产酸克雷伯菌耐药率最高,左氧氟沙星对主要革兰阳性菌普遍敏感,哌拉西林/他唑巴坦、头孢替坦对主要革兰阴性菌普遍敏感。结论失代偿期肝硬化患者出现发热寒战首先应考虑败血症可能,致病菌以革兰阴性菌多见,主要为大肠埃希菌。经验性抗菌治疗可首选哌拉西林/他唑巴坦、头孢替坦或左氧氟沙星。     

Genetic relatedness and antimicrobial resistance determinants among clinical isolates of enterococci from Cuba

This study describes the genetic relationships and antimicrobial resistance determinants found among 99 clinical isolates of enterococci from 15 different hospitals in Cuba. Pulsed-field gel electrophoresis SmaI analysis demonstrated a high degree of genetic diversity. A limited number of multiresistant Enterococcus faecalis clones, showing resistance to three or more families of antimicrobial agents, were detected simultaneously in different institutions, suggesting inter-hospital circulation of selected clones, and/or selection of particular clones following their introduction into the hospital environment. Antimicrobial resistance determinants, including erm(B), aac(6')-aph(2'), aph(3'), ant(6), vanB (E. faecalis) and vanA (Enterococcus faecium) were detected by PCR in various isolates.     

Coagulase-negative staphylococci causing blood stream infection at an Indian tertiary care hospital: Prevalence,antimicrobial resistance and molecular characterisation

Introduction: Recent years have seen a rise of coagulase-negative staphylococci (CoNS) from common contaminants to agents of nosocomial blood stream infections (BSI’s). Molecular typing and establishing a correlation with antibiotic resistance is essential particularly in countries like India where genotyping studies for drug-resistant CoNS are sparse. Methods: A prospective study was done over 18 months, wherein 42,693 blood samples were received, and 59 patients with BSI due to CoNS were evaluated. The isolates recovered were identified by a biochemical test panel and matrix-assisted laser desorption ionization – time of flight mass spectrometry followed by antimicrobial susceptibility testing by Kirby–Baur disc diffusion method and E-test strips. Staphylococcal chromosomal cassette mec (SCCmec) element was characterised by multiplex polymerase chain reaction for all methicillin-resistant (MR) isolates. Results: The majority of CoNS isolated were constituted by Staphylococcus haemolyticus (47.5%) followed by Staphylococcus epidermidis (33.9%), Staphylococcus hominis (11.86%), Staphylococcus cohnii (5.08%) and Staphylococcus warneri (1.69%). Among all isolates 57.6% were MR with statistically significant higher resistance versus methicillin sensitive-CoNS. This difference was significant for erythromycin (76% vs. 44%, P = 0.011), rifampicin (50% vs. 12%, P = 0.002) and amikacin (26.5% vs. 4%, P = 0.023), ciprofloxacin (64.7% vs. 20%, P = 0.001) and cotrimoxazole (55.9% vs. 20%, P = 0.006). SCCmec type I was predominant (61.8%, P = 0.028) and exhibited multidrug resistance (76.2%). Coexistence of SCCmec type I and III was seen in 8.82% MR isolates. Conclusion: CoNS exhibit high antimicrobial resistance thereby limiting treatment options. The presence of new variants of SCCmec type in hospital-acquired CoNS may predict the antibiotic resistance pattern. This is the first evaluation of the molecular epidemiology of CoNS causing BSI from India and can serve as a guide in the formulation of hospital infection control and treatment guidelines.