VanB表型-vanA基因型VRE分子特征及遗传背景研究

目的 探讨VanB表型-vanA基因型VRE耐药转座子结构、分子特征及遗传背景,并与VanA表型-vanA基因型VRE进行比较分析,以确定基因型与表型不一致的形成机制.方法 收集2008年3月至2009年1月卫生部北京医院临床标本中21株VRE菌株,用Etest法对10种抗生紊进行MIC测定,并通过PCR、序列测定、接合试验、耐药转座子结构、PFGE及MLST进行分子特征和遗传背景研究.结果 21株VRE均为vanA基因型,其中3株菌呈现VanB表型(万古霉素耐药,替考拉宁敏感);21株菌属于9个不同PFGE型,6个不同MIST型;多对引物对转座子的不同区域PCR扩增并进行序列拼接、比对,发现Tn1546结构中vanX、vanY的缺失及ISEfa4的插入与VanB表型-vanA基因型VRE菌株形成相关.结论 VanB表型-vanA基因型VRE菌株在国内较为罕见,Tn1546结构的改变与菌株的基因型与表型不一致相关.     

High occurrence and persistence of antibiotic-resistant enterococci in poultry food samples in Portugal

OBJECTIVES: We determined the presence of antibiotic-resistant enterococci (ARE) in commercialized poultry samples from Portugal and analysed their clonal diversity and the resistance genes harboured by these strains. METHODS: Ninety-nine retail poultry samples of 10 widely commercialized brands were studied (1999-2001). Samples were enriched and plated on selective media with and without vancomycin, gentamicin, streptomycin or kanamycin. Antibiotic susceptibility was established following standard criteria. Identification and detection of genes coding for resistance were determined by PCR. Clonal relatedness was established by PFGE. RESULTS: A high percentage of samples contained vancomycin-resistant enterococci (VRE) (48%), or enterococci highly resistant (HLR) to gentamicin (34%), streptomycin (32%) or kanamycin (30%). Co-resistance to tetracycline, erythromycin, ciprofloxacin and quinupristin/dalfopristin was observed in most of these isolates. VRE were classified as VanA phenotype-vanA genotype (38% of samples), VanB phenotype-vanA (13%) or VanC phenotype-vanC1 (23%). All HLR to gentamicin isolates contained aac(6')-Ie-aph(2')-Ia. We detected erm(B) in both erythromycin-resistant and -susceptible isolates. Some VRE and HLR to gentamicin strains were recovered from different samples and brands. Long-term persistence of particular VRE strains (>2 years), exhibiting different Van phenotypes, was observed. CONCLUSIONS: High occurrence of ARE suggests maintenance of selective pressure by the use of antibiotics/other substances in the Portuguese poultry environment. Persistence of a number of widespread PFGE types containing different resistance genes might reflect environmental/host-adapted enterococcal strains that might contribute to the maintenance of antibiotic resistance, thus constituting a resistance reservoir that is non-sensitive to banning interventions.     

European survey of vancomycin-resistant enterococci in at-risk hospital wards and in vitro susceptibility testing of ramoplanin against these isolates

A survey in eight European countries, including 13 hospitals, of vancomycin-resistant enterococci (VRE) in at-risk hospital wards (such as the ICU and the haematology ward) was performed in 2001, and the in vitro susceptibility of the isolates ramoplanin and other drugs was tested. A total of 1314 non-duplicate clinical enterococcal isolates were collected, and 38 (2.9%) were vancomycin resistant: 27 Enterococcus faecium and 11 Enterococcus faecalis; 35 VanA and three VanB phenotypes. Rates of VRE among clinical enterococcal isolates varied between 0 and 1.7% for the participating countries, except the UK (10.4%) and Italy (19.6%). One hundred and twenty-three (3.5%) VRE were found among 3499 stool samples tested for the presence of these organisms: 111 (3.2%) E. faecium and 12 (0.3%) E. faecalis; 114 (3.3%) VanA and nine (0.3%) VanB phenotypes. Rates of intestinal colonization with VRE varied between 0 and 1.2% for the participating countries, except Italy (7.5%) and the UK (32.6%). In vitro susceptibility testing showed that the Italian and UK VRE are multi-resistant (including resistance to ampicillin and high-level resistance to gentamicin and streptomycin), and that ramoplanin was active against all strains of VRE, with an MIC90 of 0.5 mg/L for clinical isolates. Pulsed-field gel electrophoresis showed that the high prevalence of VRE in the Italian and UK centres was related to the monoclonal emergence and spread of three centre-specific clones. This survey suggests that in some centres in Europe, a similar situation may be encountered to that in the USA (monoclonal spread of multi-resistant VRE in at-risk wards).     

万古霉素耐药肠球菌的检测和分子流行病学分析

目的为了解本院万古霉素耐药肠球菌（VRE）的流行情况，对VRE株进行实验室检测和分子流行病学检测分析。方法采用多重PCR及测序检测万古霉素耐药基因van，Etest法测定VRE株对万古霉素、替考拉宁的耐药表型；应用脉冲场凝胶电泳（PFGE）对11株VRE进行检测流行病学分析。结果检出1株VanA、4株VanB、5株vanC1，1株VanC2，对万古霉素、替考拉宁的药敏表型与基因型一致；11株VRE中2号vanB株与5号vanB株显示出相同片段，其他VRE株则分别有多于5个区带不同。结论实验室准确检测VRE对防止VRE感染和流行是非常重要的；PFGE电泳分析结果表明了本院11株VRE医院感染为散发。     

Performance of three chromogenic VRE screening agars, two Etest(®) vancomycin protocols, and different microdilution methods in detecting vanB genotype Enterococcus faecium with varying vancomycin MICs

Frequencies of vanB-type Enterococcus faecium increased in Europe during the last years. VanB enterococci show various levels of vancomycin MICs even below the susceptible breakpoint challenging a reliable diagnostics. The performance of 3 chromogenic vancomycin-resistant enterococci (VRE) screening agars, 2 Etest® vancomycin protocols, and different microdilution methods to detect 129 clinical vanB E. faecium strains was investigated. Altogether, 112 (87%) were correctly identified as VanB-type Enterococcus by microdilution MICs. An Etest® macromethod protocol was more sensitive than the standard protocol while keeping sufficient specificity in identifying 15 vanA/vanB-negative strains. Three chromogenic VRE agars performed similarly with 121 (94%), 123 (95%), and 124 (96%) vanB isolates that grew on Brilliance^TM VRE Agar, CHROMagar^TM VRE, and chromID^TM VRE agar, respectively. Using identical media and conditions, we did not identify different growth behaviour on agar and in broth. A few vanB strains showed growth of microcolonies inside the Etest® vancomycin inhibition zones, suggesting a VanB heteroresistance phenotype.     

CPT-EIA assays for the detection of vancomycin resistant vanA and vanB genes in enterococci

Cycling Probe Technology (CPT) was combined with a colorimetric enzyme-immuno assay (EIA) to develop two assays for the detection of vanA and vanB genes in vancomycin resistant enterococci (VRE). The CPT-EIA assay employs a gene-specific fluorescein labeled DNA-RNA-DNA probe that gets cleaved within the probe : target duplex. The cleaved DNA probe fragments dissociate from the target, making it available for further cycling. Following the separation of cleaved probe fragments, anti-fluorescein-horseradish peroxidase antibodies are used for the detection of uncleaved probes. The two CPT-EIA assays were used to screen a collection of 440 clinical isolates (Modrusan et al., 1999). All of the 154 VanA and 131 VanB isolates were correctly identified in the vanA and vanB CPT-EIA, respectively. The VanA and VanB isolates were differentiated from vancomycin sensitive enterococci (VSE) and also from the VanC isolates. In addition, an accurate VRE detection in the CPT-EIA assay was shown with cultures grown on eight different media.     

258株肠球菌耐药性分析及耐万古霉素基因检测

目的研究肠球菌的耐药率及耐万古霉素肠球菌(VRE)的耐药表型和基因型。方法按照美国临床和实验室标准化研究所(CLSI)2009年推荐的微量稀释法进行临床分离肠球菌对各类药物的最小抑菌浓度(MIC)检测,VRE进一步用E-test药敏试验确认;PCR法检测VRE的耐药基因。结果 2010年7月至2011年11月沈阳军区总医院共检出粪肠球菌95株,屎肠球菌163株。粪肠球菌对万古霉素、替考拉宁保持较高敏感度,对氨苄西林、青霉素、呋喃妥因三种抗菌药物敏感度也在65%以上,对其他抗菌药物敏感度低,统计期内未检出耐万古霉素粪肠球菌菌株。屎肠球菌对多数抗菌药物表现为耐药,对氯霉素敏感率为70%,对万古霉素、替考拉宁敏感度下降,为90.7%。期间检出15株VRE,其耐药表型为多重耐药,PCR扩增结果显示,15株万古霉素耐药屎肠球菌VanA基因扩增均为阳性,产物长度在700～1000bp之间,约783bp,符合预期;VanB、VanC引物扩增均阴性。15株万古霉素耐药屎肠球菌对多数抗菌药物耐药,仅对氯霉素、四环素相对敏感,对万古霉素MIC>256mg/L,对替考拉宁也表现为耐药。结论屎肠球菌耐药性高于粪肠球菌,VRE多为多重耐药,给临床治疗带来困难,医院应加强对其预防监测。     

Enterococcus

Enterococci have a variety of intrinsic antibiotic resistances, and also they can acquire new antibiotic resistance determinants including mutated ligase genes such as VanA or VanB. The increased prevalence and dissemination of multidrug-resistant Enterococci (i.e., Vancomycin resistant Enterococci: VRE) worldwide have resulted in a major decrease in therapeutic options and poor prognosis of infections by these organisms. Newer antibiotics, linezolid, Q/D, daptomycin and tigecycline have good in vitro activity against, however their clinical use are limited in certain infectious diseases. Although the prevalence of VRE in Japan is still quite low, strict infection control measures including active surveillance and regional information sharing is necessary to prevent dissemination in hospitals and regions.     

Surveillance of vancomycin-resistant <Emphasis Type="Italic">Enterococcus</Emphasis> in hospitals in Ibaraki prefecture

We surveyed the prevalence of vancomycin-resistant Enterococcus (VRE) in six hospitals in Ibaraki prefecture. Three hundred and fifty-five fecal specimens were examined and 18 Enterococcus intermediately resistant to vancomycin were isolated. All of them were vanC genotypes (16 vanC-1 and 2 vanC-2 genotypes) and susceptible or intermediately resistant to ampicillin, teicoplanin, linezolid, and quinupristin-dalfopristin. Neither the vanA nor vanB gene was detected. Two of the vanC genotypes were not motile. We concluded that VRE of either VanA or VanB phenotype or those highly resistant to the antibiotics commonly used against enterococcal infection were not epidemic in this prefecture to date. In addition, we consider that detection of vancomycin-resistant genes should be encouraged for the characterization of VRE, because the vanC genotypes are occasionally motility-negative and can be misinterpreted as other Enterococcus species.     

High frequency of vancomycin-resistant Enterococcus faecium isolates with VanB phenotype and vanA genotype in Korean hospitals

A total of 59 vancomycin-resistant Enterococcus faecium (VREF) clinical isolates were collected from 8 Korean hospitals for 2 months in 2004. They were investigated by genotyping for glycopeptide resistance, multilocus sequence typing (MLST), esp repeat profiling, and structural analysis of Tn1546-like element. Nine of 59 VREF isolates (15.3%) from 5 hospitals in Korea showed VanB phenotype, but they contained vanA gene. MLST and esp repeat profiling indicated that E. faecium isolates with VanB phenotype and vanA genotype occurred from independent genetic background except 3 isolates from 1 hospital. Structural analysis of Tn1546 also showed that these isolates were not clonally related. Data showed a relatively high frequency of VREF isolates with incongruence between phenotype and genotype for glycopeptide resistance in Korean hospitals.     

Van genotype and molecular typing of clinical isolates of vancomycin-resistant Enterococcus北大核心CSCD

Objective To determine the genotype and molecular typing of vancomycin-resistant Enterococcus (VRE). Methods Seventeen clinical isolates of VRE were collected in 2016. The strains were identified to species and confirmed by 16S rRNA sequencing. The minimum inhibitory concentration of antimicrobial agents was determined by microdilution method and agar dilution method. Multilocus sequence typing (MLST) was used for molecular typing. Results The VRE strains were confirmed as Enterococcus faecium by 16S rRNA sequencing. All strains were resistant to vancomycin, but only 12 strains were resistant to teicoplanin. The vanA gene was identified in 13 of the 17 strains. The vanM gene was detected in 9 strains. Both vanA and vanM genes were identified in five of the 17 strains. Six MLST types were identified in the 17 strains, including ST78 (n=8), ST80 (n=4), ST555 (n=2), and one each for ST117, ST262 and ST341. Conclusions The van genotype was primarily vanA (76.5%) and vanM (52.9%) in clinical isolates of VRE. The VRE strains carrying both vanA and vanM were found for the first time. © 2018, Editorial Department of Chinese Journal of Infection. All rights reserved.     

Antibiotic activity against urinary tract infection (UTI) isolates of vancomycin-resistant enterococci (VRE): results from the 2002 North American Vancomycin Resistant Enterococci Susceptibility Study (NAVRESS)

BACKGROUND: The purpose of this study was to assess the prevalence of vancomycin-resistant enterococci (VRE) in urinary isolates in North America, and the activity of various antibiotics against VRE. MATERIALS AND METHODS: Twenty-eight medical centres in the United States and 10 centres in Canada assessed the prevalence of VRE in urinary isolates in 2002. Each study site was asked to collect up to a maximum of 50 consecutive VRE (Enterococcus faecium, Enterococcus faecalis only) urinary isolates. Susceptibility was determined by NCCLS broth microdilution. The prevalence of vanA and vanB resistance genotypes was determined by multiplex PCR. RESULTS: From the 28 US medical centres, a total of 697 VRE (616 [88.4%] E. faecium and 81 [11.6%] E. faecalis) were received. Approximately 75% of all VRE (E. faecium and E. faecalis) isolates demonstrated a VanA phenotype (resistance to both vancomycin and teicoplanin). PCR detection of vanA and vanB resistance determinants showed that the vanA genotype was present in 584 of 697 (83.8%) VRE isolates, whereas 113 (16.2%) isolates possessed the vanB gene. The most active agents were linezolid, nitrofurantoin and chloramphenicol, with 0.3%, 0.6% and 2.4% resistance, respectively. The majority (77.8%) of vancomycin-resistant E. faecium isolates displayed the VanA phenotype, and 538 of these 616 (87.3%) isolates were PCR-positive for vanA; the vanB genotype was detected in 78 (12.7%) isolates. Resistance was lowest with linezolid, chloramphenicol and nitrofurantoin at 0.3%, 0.3% and 0.5%, respectively. Only three genetically indistinguishable vanA-positive E. faecium were isolated from the 10 Canadian medical centres. CONCLUSION: VRE urinary isolates are common in the United States, are primarily of the vanA genotype and are very susceptible to linezolid, nitrofurantoin and chloramphenicol. In Canada, VRE urinary isolates remain uncommon.     

A new Tn1546 type of VanB phenotype–vanA genotype vancomycin-resistant Enterococcus faecium isolates in mainland China

VanB phenotype–vanA genotype vancomycin-resistant Enterococcus faecium (VREF) has never been reported in mainland China. We investigated the frequency and molecular characteristics of this strain in a Beijing tertiary hospital. Of 23 vanA genotype VREF clinical isolates, 12 (54.3%) were VanB phenotype–vanA genotype. Mutilocus sequence typing (MLST) analysis revealed that all isolates belong to a single clonal complex (CC78), which has been disseminated worldwide. Based on MLST and pulsed-field gel electrophoresis, 23 isolates were polyclonal dissemination in our hospital. Tn1546-like element structure analysis showed that of 12 VanB phenotype–vanA genotype isolates, 5 had complete deletion of vanY and vanZ accompanying insertion of IS1216V in vanX–vanY intergenic region, 5 had ISEfa4 insertion in orf2–vanR intergenic region, a new Tn1546 structure type, and 2 were identical to VanA phenotype–vanA genotype VREF. Data showed that the deletion of vanY and vanZ genes or ISEfa4 insertion in orf2–vanR intergenic region can partly explain the causes of difference between phenotype and genotype.     

Antimicrobial resistance and molecular epidemiology of vancomycin-resistant enterococci from North America and Europe: a report from the SENTRY antimicrobial surveillance program

Increases in prevalence of vancomycin-resistant enterococci (VRE) have been documented globally since its emergence in the 1980s. A SENTRY Antimicrobial Surveillance Program (2003) objective monitored VRE isolates with respect to antimicrobial susceptibility trends, geographic resistance variability, and clonal dissemination. In 2003, VRE isolates from North America (United States and Canada, n = 839, 26 sites) and Europe (n = 56, 10 sites) were susceptibility tested using Clinical and Laboratory Standards Institute (CLSI) reference methodologies. Based on resistance profiles, 155 isolates displayed similar multidrug-resistant (MDR) profiles and were temporally related; these were subsequently submitted for typing by pulsed-field gel electrophoresis (PFGE). Most of the submitted isolates were Enterococcus faecium (91.0%) and Enterococcus faecalis (7.8%). Among VRE, the VanA phenotype was more prevalent in North America (76%) than Europe (40%), and all isolates had elevated resistance rates to other antimicrobial classes including the following: 1) chloramphenicol resistance among E. faecalis being greater in North America than in Europe (28.6% versus 7.1%, respectively) but reversed among E. faecium (0.5% and 15.0%, the latter due to clonal occurrences); 2) ciprofloxacin resistance in North America >99% for both species and in Europe varying from 85.7% to 87.5%; 3) rare occurrences of linezolid resistance in North America (0.8% to 1.8%) due to G2576U ribosomal mutation; 4) higher quinupristin/dalfopristin resistance observed among European E. faecium strains (10.0% versus 0.6%); and 5) higher rifampin resistance rates among European E. faecalis (21.4% versus 5.4%). Thirty-five MDR epidemic clusters were identified by PFGE in 21 North American and 2 European medical centers including the following: 1) VanA (20 sites, 27 clonal occurrences) and VanB (1 site, 2 clonal occurrences); 2) elevated quinupristin/dalfopristin MIC results (not vatD/E, 3 sites); and 3) chloramphenicol resistance (chloramphenicol acetyltransferase-positive strains, 3 sites). The esp gene, part of the putative E. faecium pathogenicity island and a marker for the clonal complex-17 lineage, was detected in 76% of vancomycin-resistant E. faecium. Clonal spread appears to be a dominant factor of MDR VRE dissemination on both continents, and further monitoring is critical to assist in the control of these resistant pathogens.     

耐万古霉素肠球菌表型检测及基因分型

目的 研究对万古霉素耐药或中介的肠球菌株的表型和基因型，以了解本院耐万古霉素肠球菌（VRE）的流行状况，指导临床合理用药。方法 收集200株临床分离的肠球菌株，用琼脂筛选法筛选VRE，并分别用E test和多重PCR检测和分析对万古霉素耐药或中介肠球菌株的表型和基因型。结果 共检出10株对万古霉素耐药或中介的肠球菌株，其中5株为天然耐万古霉素肠球菌。基因型分析的结果为1株van A型，4株van C1型，3株van C2型，2株基因型不明。结论 已发现5株VRE（1株VAN A型），提示临床上须合理使用抗生素，以防止VRE等多重耐药细菌的爆发流行。     

Detection of vancomycin resistant genes vanA and vanB by cycling probe technology.

Cycling Probe Technology (CPT) has been used to develop gene-based assays for detection of vancomycin resistance genes vanA and vanB in enterococci (VRE). Cycling Probe Technology utilizes a chimeric DNA-RNA-DNA probe that is cleaved by the enzyme RNase H when hybridized to its complementary DNA target. Conversion of full-length probe into the cleaved probe fragments is the basis for detection and quantification of the CPT reaction. Two gene-specific probes, each one unique to either the vanA or vanB gene, were utilized for development of vanA and vanB CPT assays, respectively. Both vanA and vanB CPT assays were used to determine the presence or absence of the corresponding gene in 440 clinical enterococcal isolates. The presence of vanA and vanB gene sequences was detected in 154 and 131 isolates, respectively. Phenotypic characterization of all isolates was determined through interpretation of conventional susceptibility data obtained with the disk diffusion method. Comparison between disk diffusion characterization and CPT assays revealed 11 discrepant isolates. The identity of these isolates was resolved by polymerase chain reaction (PCR) which confirmed the vanA and vanB CPT assay data. Therefore, compared to conventional phenotyping, both the vanA and vanB CPT assays appeared superior for accurate identification of VanA and VanB isolates.     

A nationwide, multicenter, case-control study comparing risk factors, treatment, and outcome for vancomycin-resistant and -susceptible enterococcal bacteremia

National Nosocomial Resistance Surveillance Group participants from 22 hospitals across the United States reviewed medical records for hospitalized patients with vancomycin-resistant enterococcal (VRE) or vancomycin-susceptible enterococcal (VSE) bacteremia to identify risk factors associated with the acquisition of VRE bacteremia, describe genetic traits of VRE strains, and identify factors predictive of clinical outcome. VRE cases were matched to VSE controls within each institution. Multiple logistic regression (LR) and classification and regression tree (CART) analysis were used to probe for factors associated with VRE bacteremia and clinical outcome. A total of 150 matched-pairs of VRE cases and VSE controls were collected from 1995 to 1997. Using LR, the following were found to be highly associated with VRE bacteremia: history of AIDS, positive HIV status, or drug abuse (OR 9.58); prior exposure with parenteral vancomycin (OR 8.37); and liver transplant history (OR 6. 75). CART analysis revealed that isolation of Enterococcus faecium, prior vancomycin exposure, and serum creatinine values > or = 1.1 mg/dl were predictors of VRE bacteremia. Greater proportions of clinical failure (60% versus 40%, P < 0.001) and all-cause mortality (52% versus 27%, P < 0.001) were seen in patients with VRE versus VSE bacteremia. Results from both LR and CART indicated that patients with persisting enterococcal bacteremia, intubation at baseline, higher APACHE II scores, and VRE bacteremia were at greater risk for poor outcome.     

A clonal lineage of VanA-type Enterococcus faecalis predominates in vancomycin-resistant Enterococci isolated in New Zealand

Avoparcin was used as a feed additive in New Zealand broiler production from 1977 until June 2000. We report here on the effects of the usage and discontinuation of avoparcin on the prevalence of vancomycin-resistant enterococci (VRE) in broilers. Eighty-two VRE isolates were recovered from poultry fecal samples between 2000 and mid-2001. VRE isolates were only obtained from broiler farms that were using, or had previously used, avoparcin as a dietary supplement. Of these VRE isolates, 73 (89%) were VanA-type Enterococcus faecalis and nine (11%) were VanA-type Enterococcus faecium. All E. faecalis isolates were found to have an identical or closely related pulsed-field gel electrophoresis (PFGE) pattern of SmaI-digested DNA and were susceptible to both ampicillin and gentamicin. The PFGE patterns of the nine E. faecium isolates were heterogeneous. All VRE contained both the vanA and ermB genes, which, regardless of species or PFGE pattern, resided on the same plasmid. Eighty-seven percent of the VRE isolates also harbored the tet(M) gene, while for 63 and 100%, respectively, of these isolates, the avilamycin and bacitracin MICs were high (>or=256 microg/ml). Five of eight vancomycin-resistant E. faecalis isolates recovered from humans in New Zealand revealed a PFGE pattern identical or closely related to that of the E. faecalis poultry VRE isolates. Molecular characterization of Tn1546-like elements from the VRE showed that identical transposons were present in isolates from poultry and humans. Based on the findings presented here, a clonal lineage of VanA-type E. faecalis dominates in VRE isolated from poultry and humans in New Zealand.     

The effect of pulsed-xenon ultraviolet disinfection on surfaces contaminated with vancomycin-resistant Enterococci in a Japanese hospital

IntroductionRecently, a worldwide outbreak of vancomycin-resistant Enterococci (VRE) was reported. However, due to the low incidence of VRE infection and colonization, VRE contamination of hospital environments has not been fully investigated in Japan.MethodsSurfaces were swabbed, before and after manual cleaning and after pulsed xenon ultraviolet (PX-UV) disinfection, in five patient rooms that had been occupied by patients colonized with VRE. Difference in the number of VRE-positive samples and VRE colony forming units (CFUs), before and after disinfection, for each cleaning method was estimated.ResultsWe detected VRE contamination in 22/60 (37%) and 14/60 (23%) samples collected before and after manual cleaning, respectively. In contrast, VRE contamination was not detected in the samples collected after PX-UV disinfection. In addition, 3/5 (60%) spray nozzles of electric warm-water bidet toilet seats were found to be contaminated with VRE before terminal cleaning. Manual cleaning caused a significant decrease in the number of VRE CFUs compared with that before cleaning (P = 0.031). PX-UV disinfection also caused a significant decrease in the number of VRE CFUs compared to that of manual cleaning (P < 0.001).ConclusionWe identified hot spots of severe contamination, such as private bathrooms in patient rooms and areas around the bed of patients using diapers and required assistance. VRE contamination persisted even after terminal disinfection; PX-UV disinfection in addition to terminal disinfection was effective at eliminating VRE contamination. These results can be useful in controlling the spread of VRE infections in Japanese hospitals.     

A comparison of high-level aminoglycoside resistance in vancomycin-sensitive and vancomycin-resistant Enterococcus species

The aim of this study was to investigate whether there was a significant difference in high-level aminoglycoside resistance (HLAR) between vancomycin-sensitive enterococci (VSE) and vancomycin-resistant enterococci (VRE). Vancomycin resistance was determined in 116 Enterococcus isolates using brain-heart infusion agar containing 6 micrograms/ml vancomycin. HLAR was determined by both standard agar screening and disk diffusion methods. Streptomycin and gentamicin were used as predictors of HLAR. Vancomycin resistance and HLAR were found in 17 (14.7%) and 41 (35.3%) of the Enterococcus strains, respectively. HLAR was found in 11 of 17 VRE and 30 of 98 VSE strains. HLAR in VRE strains was significantly higher than in VSE. More enterococcal strains were found to be resistant to both gentamicin and streptomycin (29) than to gentamicin (one) or streptomycin (11) alone. The HLAR rate in VRE was two-fold higher than in VSE. The synergistic bactericidal effect of aminoglycosides and beta-lactam or glycopeptide antibiotics is lost if there is high-level resistance to aminoglycosides.