ABSTRACT The antifungal susceptibility profile and epidemiological cut-off values (ECOFFs) of Yarrowia lipolytica, a rare opportunistic yeast, remain unclear. We conducted a comprehensive multi-method study on clinical isolates from various central hospitals, based on the China Hospital Invasive Fungal Surveillance Network (2009–2022). Our objective was to evaluate the antifungal susceptibility of Y. lipolytica, establish its local ECOFFs (L-ECOFFs), and compare the performance of the ATB FUNGUS 3 (ATB), Sensititre YeastOne (SYO), and minimum inhibitory concentration (MIC) test strip (MTS) with that of the broth microdilution (BMD) method. L-ECOFFs were established using ECOFFinder, and we examined ERG11 mutations to assess the reliability of the L-ECOFFs. The L-ECOFF for fluconazole was 8 µg/mL. Non-wild-type isolates of antifungal drugs, such as flucytosine and azoles, were exclusively isolated from patients. Additionally, we detected that four strains with the ERG11 A395T mutation (azole MIC >L-ECOFF) may be associated with the exposure to azole drugs. For azoles, ATB showed the highest essential agreement with the BMD (98.18%–100%), followed by SYO (85.45%–100%). However, ATB could not detect susceptibility to echinocandins, while SYO exhibited the highest agreement (98.18%–100%) in detecting echinocandin susceptibility. Our findings indicate that acquired azole cross-resistance has emerged despite Y. lipolytica infections being rare. This research provides crucial antifungal susceptibility data and establishes the initial L-ECOFFs for Y. lipolytica. The SYO is recommended as the optimal laboratory antifungal susceptibility testing method for Y. lipolytica, followed by ATB, whereas the use of MTS requires caution. We hope that this study will facilitate improved clinical management of Y. lipolytica infections. IMPORTANCE Yarrowia lipolytica, also known as Candida lipolytica, is an emerging opportunistic “rare pathogenic yeast”. Due to the limited data on its antifungal susceptibility, the clinical treatments become challenging. Based on the China Hospital Invasive Fungal Surveillance Network (2009–2022), we conducted a comprehensive multi-method study on clinical isolates from various central hospitals. This study is currently the largest study carried out to assess the antifungal susceptibility of Y. lipolytica. It is also the first to establish local epidemiological cut-off values (L-ECOFFs), identify its ERG11 mutations, and assess the consistency between the three prevalent commercial antifungal susceptibility testing methods and the broth microdilution method. We recommend the Sensititre YeastOne as the best option for antifungal susceptibility testing for Y. lipolytica, followed by the ATB FUNGUS 3. Nevertheless, practitioners should use the MIC test strip with discretion.
Candida albicans remains the most common species causing invasive candidiasis. In this study, we present the population structure of 551 global C. albicans strains. Of these, the antifungal susceptibilities of 370 strains were tested. Specifically, 66.6% of the azole-nonsusceptible (NS)/non-wild-type (NWT) strains that were tested belonged to Clade 1. A phylogenetic analysis, a principal components analysis, the population structure, and a loss of heterozygosity events revealed two nested subclades in Clade 1, namely, Clade 1-R and Clade 1-R-α, that exhibited higher azole-NS/NWT rates (75.0% and 100%, respectively). In contrast, 6.4% (21/326) of the non-Clade 1-R isolates were NS/NWT to at least 1 of 4 azoles. Notably, all of the Clade 1-R-α isolates were pan-azole-NS/NWT that carried unique A114S and Y257H double substitutions in Erg11p and had the overexpression of ABC-type efflux pumps introduced by the substitution A736V in transcript factor Tac1p. It is worth noting that the Clade 1-R and Clade 1-R-α isolates were from different cities that are distributed over a large geographic span. Our study demonstrated the presence of specific phylogenetic subclades that are associated with antifungal resistance among C. albicans Clade 1, which calls for public attention on the monitoring of the future spread of these clones. IMPORTANCE Invasive candidiasis is the most common human fungal disease among hospitalized patients, and Candida albicans is the predominant pathogen. Considering the large number of infected cases and the limited alternative therapies, the azole-resistance of C. albicans brings a huge clinical threat. Here, our study suggested that antifungal resistance in C. albicans could also be associated with phylogenetic lineages. Specifically, it was revealed that more than half of the azole-resistant C. albicans strains belonged to the same clade. Furthermore, two nested subclades of the clade exhibited extremely high azole-resistance. It is worth noting that the isolates of two subclades were from different cities that are distributed over a large geographic span in China. This indicates that the azole-resistant C. albicans subclades may develop into serious public health concerns.
Purpose The objective of this study was to investigate the molecular characteristics and potential resistance mechanisms of linezolid-resistant (LZR) Staphylococcus capitis isolates from a tertiary hospital in China. Methods S. capitis isolates were obtained from clinical patient specimens; three of the isolates came from blood cultures and one from the hydrothorax. The agar dilution and E-test methods were used to identify antibiotic resistance. The chloramphenicol-florfenicol resistance (cfr) gene carrier status of the strains was determined by PCR. Whole-genome sequencing (WGS) was used to identify point mutations and L3, L4, and L22 mutations and to study the genetic environment of the cfr gene and the relationships between strains. Results The 4 isolates obtained in this study were all linezolid-resistant Staphylococcus strains. A similar of susceptibility profile pattern was observed in all four S. capitis strains, each of which exhibited a multidrug-resistant phenotype. A potentially novel mutation, C2128T, was identified, and the cfr genes of S. capitis strains were all positive. Additionally, the same mutations (C2128T and G2600T) were identified in all 23S rRNA sequences of the isolates, whereas mutations were lacking in the L3, L4, and L22 ribosomal proteins. The genetic environments surrounding cfr were identical in all four isolates. A schematic diagram of the phylogenetic tree showed that they were closely related to AYP1020, CR01, and TW2795, and a total of seven drug resistance genes were identified in these strains. Conclusions The study indicated that the resistance of the Staphylococcus capitis strains to linezolid was caused by multiple mechanisms, and a potential novel mutation, C2128T, that may have an impact on bacterial resistance was identified.
Background/Purpose: There are limited studies on species distribution and suscep-tibility profiles of Aspergillus strains isolated from patients with otomycosis in China.Methods: A total of 69 confirmed Aspergillus species isolates were obtained from ear swabs of patients diagnosed with otomycosis from 2017 to 2018 in northern China. Identification of these Aspergillus isolates at the species level was performed using conventional morphological methods and MALDI-TOF MS in combination with molecular sequencing, and in vitro suscepti-bility to nine antifungal agents was evaluated using the Sensititre YeastOne system.Results: The Aspergillus section Nigri had the greatest distribution of Aspergillus isolates. A. welwitschiae (n = 25) was the most predominant isolate in section Nigri, followed by A. tu-bingensis (n = 12) and A. niger (n = 11). Other Aspergillus species were also isolated, including A. terreus (n = 11), A. flavus/A. oryzae (n = 8), and A. fumigatus (n = 2). Ampho-tericin B, posaconazole, and echinocandins were highly in vitro active against all the isolates tested. 2.9% (2/69) of the isolates were resistant to azoles in our study, including one A. niger isolate with a high MIC value for itraconazole (ITR) (16 mg/L) and one A. tubingensis isolate cross-resistant to both voriconazole (VOR) (MIC >8 mg/L) and ITR (MIC >16 mg/L). One A. wel-witschiae and one A. niger isolate both had increased MIC values of 4 mg/L against VOR.Conclusions: A. welwitschiae was the most prevalent Aspergillus species isolated from pa-tients with otomycosis. Our findings also indicated that the azole-resistant Aspergillus section Nigri should be utilized to guide clinical medication for Otomycosis.Copyright (c) 2021, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Filamentous fungi identification by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been challenging due to the lack of simple and rapid protein extraction methods and insufficient species coverage in the database. In this study, we created two rapid protein extraction methods for filamentous fungi: a one-step zirconia-silica beads method (ZSB) and a focused-ultrasonication method (FUS). The identification accuracy of two methods were evaluated with the VITEK MS, as well as number of spectra peaks and signal-to-noise ratio (S/N) with M-Discover 100 MALDI-TOF MS compared to the routine method. The better method was applied to build a filamentous fungi in-house spectra library for the M-Discover 100 MS, and then another one and routine method were performed in parallel to verify the accuracy and commonality of the in-house library. Using the two optimized methods, the dedicated operating time before MALDI-TOF MS analysis was reduced from 30 min to 7 (ZSB) or 5 (FUS) min per sample, with only a few seconds added for each additional strain. And both two methods identified isolates from most mold types equal to or better than the routine method, and the total correct identification rate using VITEK MS was 79.67, 76.42, and 76.42%, respectively. On the other hand, the two rapid methods generally achieved higher maximum and minimum S/N ratios with these isolates tested as compared to the routine method. Besides, the ZSB method produced overall mean of maximum and minimum S/N ratio higher than that by FUS. An in-house library of M-Discover MS was successfully built from 135 isolates from 42 species belonging to 18 genera using the ZSB method. Analysis of 467 isolates resulted in 97.22% correctly identified isolates to the species level by the ZSB method versus 95.50% by the routine method. The two novel methods are time- and cost-effective and allow efficient identification of filamentous fungi while providing a simplified procedure to build an in-house library. Thus, more clinical laboratories may consider adopting MALDI-TOF MS for filamentous fungi identification in the future.
Diutina catenulata (Candida catenulata) is an ascomycete yeast species widely used in environmental and industrial research and capable of causing infections in humans and animals. At present, there are only a few studies on D. catenulata, and further research is required for its more in-depth characterization and analysis. Eleven strains of D. catenulata collected from China Hospital Invasive Fungal Surveillance Net (CHIF-NET) and the CHIF-NET North China Program were identified using matrix-assisted laser desorption ionization–time of flight mass spectrometry and internal transcribed spacer sequencing. The antifungal susceptibility of the Diutina catenulata strains was tested using the Clinical and Laboratory Standards Institute broth microdilution method and Sensititre YeastOne™. Furthermore, ERG11 and FKS1 were sequenced to determine any mutations related to azole and echinocandin resistance in D. catenulata. All isolates exhibited low minimum inhibitory concentration (MIC) values for itraconazole (0.06–0.12 μg/ml), posaconazole (0.06–0.12 μg/ml), amphotericin B (0.25–1 μg/ml), and 5-flucytosine (range, <0.06–0.12 μg/ml), whereas four isolates showed high MICs (≥4 μg/ml) for echinocandins. Strains with high MIC values for azoles showed common ERG11 mutations, namely, F126L/K143R. In addition, L139R mutations may be linked to high MICs of fluconazole. Two amino acid alterations reported to correspond to high MIC values of echinocandin, namely, F621I (F641) and S625L (S645), were found in the hot spot 1 region of FKS1. In addition, one new amino acid alteration, I1348S (I1368), was found outside of the FKS1 hot spot 2 region, and its contribution to echinocandin resistance requires future investigation. Diutina catenulata mainly infects patients with a weak immune system, and the high MIC values for various antifungals exhibited by these isolates may represent a challenge to clinical treatment.
Inflammatory bowel disease (IBD) is an increasing global burden and a predisposing factor to colorectal cancer. Although a number of treatment options are available, the side effects could be considerable. Studies on fecal microbiota transplantation (FMT) as an IBD intervention protocol require further validation as the underlying mechanisms for its attenuating effects remain unclear. This study aims to demonstrate the ameliorative role of FMT in an ulcerative colitis (UC) model induced by dextran sulfate sodium (DSS) and elucidate its relative mechanisms in a mouse model. It was shown that FMT intervention decreased disease activity index (DAI) levels and increased the body weight, colon weight and colon length of experimental animals. It also alleviated histopathological changes, reduced key cytokine expression and oxidative status in the colon. A down-regulated expression level of genes associated with NF-κB signaling pathway was also observed. The results of 16S rRNA gene sequencing showed that FMT intervention restored the gut microbiota to the pattern of the control group by increasing the relative abundance of Firmicutes and decreasing the abundances of Bacteroidetes and Proteobacteria. The relative abundances of the genera Lactobacillus, Butyricicoccus, Lachnoclostridium, Olsenella and Odoribacter were upregulated but Helicobacter, Bacteroides and Clostridium were reduced after FMT administration. Furthermore, FMT administration elevated the concentrations of SCFAs in the colon. In conclusion, FMT intervention could be suitable for UC control, but further validations via clinical trials are recommended.
目的 回顾性分析2010-2014年中国侵袭性真菌耐药监测网(CHIF-NET) 62所监测中心重症监护室(ICU)侵袭性酵母的现状,了解我国侵袭性酵母分布的特征及其对唑类药物的耐药情况.方法 收集各所监测中心初步鉴定的菌株,送至北京协和医院检验科,采用基质辅助激光解吸电离飞行时间质谱技术结合分子测序技术对所有菌株进行复核鉴定,再进行唑类药物敏感性检测.结果 2010-2014年,62所监测中心ICU共检出侵袭性酵母2 863株,其中以念珠菌属最多,计2 771株.标本类型包括血液标本(50.8%,1 453/2863),无菌体液标本(49.2%,1 410/2863);其中,50.7%(1 404/2 771)的念珠菌属分离自血液标本.5年间,白念珠菌对氟康唑和伏立康唑十分敏感,敏感率>99.0%;热带念珠菌对氟康唑和伏立康唑的耐药率显著升高,均从12.2%升至23.1%(P<0.01);光滑念珠菌对氟康唑的耐药率也显著升高,从14.7%升至27.7% (P<0.01).非念珠菌属中,新型隐球菌复合体对伏立康唑全部敏感,从2013年开始出现对氟康唑耐药菌;其他酵母对两种唑类药物耐药率整体较高,分别为43.6%和32.7%.菌株复核鉴定的正确率为86.2%(2 467/2 863).结论 ICU中侵袭性酵母分离株中以念珠菌属为主,主要分离自血液,氟康唑和伏立康唑对其抗菌作用非常显著;而非白念珠菌的耐药率有不同程度的升高及交叉耐药的出现,临床需要加以重视.
目的 分析耐药结节细胞分化超家族(RND)外排泵介导多重耐药鲍曼不动杆菌(MDR-AB)对替加环素敏感性降低的机制.方法 收集2015—2018年哈尔滨医科大学附属第四医院替加环素不敏感的鲍曼不动杆菌21株及MDR-AB替加环素敏感株39株.以微量肉汤稀释法为标准方法,以替加环素不敏感菌株[最小抑菌浓度(MIC)≥2μg/mL]为实验组,替加环素敏感菌株(MIC≤1μg/mL)为对照组.采用聚合酶链反应(PCR)检测鲍曼不动杆菌替加环素敏感性降低相关的RND基因adeB、adeG和adeJ,及其上游调控基因adeS、baeR和baeS,并对adeS扩增产物进行测序,查找插入序列.采用实时荧光定量聚合酶链反应(RT-qPCR)检测实验组和对照组外排泵adeABC、adeFGH、adeIJK、adeRS和baeRS的转录水平并进行比较.结果 微量肉汤稀释法确证有12株MDR-AB为替加环素不敏感株,与替加环素敏感性降低相关的RND基因检出率为100%,且在2株菌株中发现了adeS的ISAbaⅠ插入序列.实验组有3株菌株adeABC表达较对照组明显升高,分别为标准菌株鲍曼不动杆菌(ATCC 19606)的3.3、3.5和2.7倍;有1株菌株adeFGH表达量升高明显;adeIJK、adeRS和baeRS表达量在部分菌株中稍有上调.结论 RND外排泵介导的MDR-AB对替加环素敏感性降低与adeABC和adeFGH高表达密切相关,adeABC高表达可能与其上游调控基因adeS中存在ISAbal插入突变有关,但不排除其他替加环素耐药机制的存在.
鲍曼不动杆菌是一种常见的可引起医院感染的条件致病菌,随着抗菌药物的广泛使用,越来越多的多重耐药鲍曼不动杆菌被分离出来.替加环素是治疗鲍曼不动杆菌感染的最后一道防线,近年来替加环素耐药鲍曼不动杆菌不断出现,而其耐药机制至今尚未被完全阐明.文章对鲍曼不动杆菌主动外排系统及近年新发现的耐药机制,包括修饰酶、细胞膜渗透作用、DNA损伤诱导反应及作用靶点改变等机制作一综述,为细菌耐药及新型抗菌药物研究提供理论依据,为临床控制替加环素耐药鲍曼不动杆菌提供新思路.
目的 旨在建立一种操作简便、分型分辨率高以及成本低的耐甲氧西林金黄色葡萄球菌(MRSA)分子分型方法,对多位点可变数量串联重复序列指纹法(MLVF)进行了方法学改良及分型能力比对评估.方法 应用42株MRSA参考菌株对改良MLVF分型能力进行验证;应用116株东北三省六家医院的MRSA临床菌株对改良MLVF、脉冲场凝胶电泳(PFGE)及多位点可变数量串联重复序列分析(MLVA)进行了方法学比对.结果 改良MLVF对42株参考菌株分型率为100%;改良MLVF、PFGE和MLVA分别将116株临床菌株分成28个型(simpson's多样性系数[SID]=0.855),28个型(SID=0.854)和27个型(SID=0.816).改良MLVF在区分国内最主要流行克隆CC239和其他克隆方面分辨率优于MLVA.改良MLVF在分群水平上与PFGE分型一致性(adjusted Rand's,AR系数0.989)优于MLVA(AR指数0.765).结论 改良MLVF具有分辨率高、与金标准PFGE分型一致性好、操作简单、高通量、费用低的优点,适合常规实验室对MRSA进行分子分型,为常规感控工作及分子流行病学研究提供有力工具.
Candida glabrata is an increasingly important cause of invasive candidiasis. In China, relatively little is known of the molecular epidemiology of C. glabrata and of its antifungal susceptibility patterns. Here we studied 411 non-duplicate C. glabrata isolates from 411 patients at 11 hospitals participating in the National China Hospital Invasive Fungal Surveillance Net program (CHIF-NET; 2010-2014). Genotyping was performed using multilocus sequence typing (MLST) employing six genetic loci and by microsatellite analysis. Antifungal susceptibility testing was performed using Sensititre YeastOne™ YO10 methodology. Of 411 isolates, 35 sequence types (ST) were identified by MLST and 79 different genotypes by microsatellite typing; the latter had higher discriminatory power than MLST in the molecular typing of C. glabrata. Using MLST, ST7 and ST3 were the most common STs (66.4 and 9.5% of all isolates, respectively) with 24 novel STs identified; the most common microsatellite types were T25 (30.4% of all isolates) and T31 (12.4%). Resistance to fluconazole (MIC > 32 μg/mL) was seen in 16.5% (68/411) of isolates whilst MICs of >0.5 μg/mL for voriconazole, >2 μg/mL for itraconazole and >2 μg/mL for posaconazole were seen for 28.7, 6.8, and 7.3% of isolates, respectively; 14.8% of all isolates cross-resistant/non-wide-type to fluconazole and voriconazole. Fluconazole resistant rates increased 3-fold over the 5-year period whilst that of isolates with non-WT MICs to voriconazole, 7-fold. All echinocandins exhibited >99% susceptibility rates against all isolates but notably one isolate exhibited multi-drug resistance to the azoles and echinocandins. The study has provided a global picture of the molecular epidemiology and drug resistance rates of C. glabrata in China during the period of the study.
A data analysis of yeast collections from the National China Hospital Invasive Fungal Surveillance Net (CHIF-NET) programme in 2013 revealed a sudden increase in the proportion of Candida parapsilosis complex isolates (n = 98) in one participating hospital (Hospital H). Out of 443 yeast isolates submitted to the CHIF-NET reference laboratory by Hospital H (2010–2014), 212 (47.9%) were identified as C. parapsilosis sensu stricto by sequencing analysis of the internal transcribed spacer region and D1/D2 domain of the 26S rRNA gene. Among the 212 C. parapsilosis sensu stricto isolates, 176 (83.0%) bloodstream-based isolates and 25 isolates from tip cultures of various vascular catheters from 25 patients with candidaemia, were subjected to microsatellite genotyping, and a phylogenetic relationship analysis was performed for 152 isolates. Among the 152 isolates, 45 genotypes (T01 to T45) were identified, and two prevalent genotypes (63.8%) were found: T15 (n = 74, 48.7%) and T16 (n = 23, 15.1%). These two main clones were confined mainly to three different wards of the hospital, and they persisted for 16–25 months and 12–13 months, respectively. The lack of proper coordination between the clinical microbiology laboratory and infection control staff as part of public health control resulted in the failure to timely identify an outbreak, which led to the wide and long-term dissemination of C. parapsilosis sensu stricto in Hospital H.
There are few data on the molecular epidemiology of cryptococcosis in China. Here we investigated the species distribution, molecular types and antifungal susceptibilities of 312 Cryptococcus neoformans species complex isolates from ten hospitals over 5 years. Isolates were identified by internal transcribed spacer (ITS) sequencing and by two matrix-assisted laser desorptioneionization time-of-flight mass spectrometry (MALDI-TOF MS) systems. Multilocus sequence typing (MLST) was used to verify species/ variety and to designate molecular types. Susceptibility to six antifungal drugs was determined by the Sensititre YeastOne T method. Cryptococcus neoformans was the predominant species (305/312 isolates (97.8%), all were ITS type 1, serotype A), of which 89.2% (272/305) were C. neoformans var. grubii MLST sequence type (ST) 5 and 6.2% (19/305) were ST31. Other C. neoformans var. grubii STs were rare but included six novel STs. Only two strains were C. neoformans var. neoformans (both serotype AD). Cryptococcus gattii was uncommon (n = 7, four ITS types) and comprised five MLST STs including one novel ST. For C. neoformans var. grubii, the proportion of isolates with non-wild-type MICs to fluconazole significantly rose in the fourth study year (from 0% (0/56 isolates) in the first year to 23.9% (17/71) in the fourth year), including five isolates with fluconazole MICs of >= 32 mg/L. The study has provided useful data on the species epidemiology and their genetic diversity and antifungal susceptibility. The proportional increase in isolates with non-wild-type MICs to fluconazole is noted. (C) 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
OBJECTIVE To evaluate the results of original identification ,Vitek MS and Bruker MS identification of Candida glabrata species complex collected from National China Hospital Invasive Fungal Surveillance Net (CHIF‐NET) in 2010‐2014 .METHODS A total of one C .bracarensis isolate and twelve C .nivariensis isolates were collected from the CHIF‐NET in 2010‐2014 ,and 411 C .glabrata isolates were collected from eleven hospi‐tals which participated in the CHIF‐NET in five consecutive years from 2010 to 2014 .All of the strains were iden‐tified by using molecular method ,the review identification results were set as"gold‐standard",the results of origi‐nal identification of the conventional methods were evaluated ,and the performances of Vitek MS and Bruker MS matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI‐TOF MS) in the identifica‐tion of the C .glabrata species complex were observed .RESULTS As compared with the molecular identification , the accurate rate of original identification of C .glabrata was 90 .3% ,and 9 .7% of the strains were mistakenly i‐dentified as Candida parapsilosis and Candida albicans by CHROMagar chromogenic media ,ID 32C ,API 20C or Vitek 2 Compact system .C .nivariensise and C .bracarensis could not be identified by using routine identification methods .The accurate rates of the Vitek MS and Bruker MS were 97 .6% and 100 .0% ,respectively .There were no reference spectra for C .bracarensis and C .nivariensis in the Vitek MS 2 .0 database ,so the two species could not be identified .There were reference spectra for the two species in the Bruker Biotyper 3 .1 database ,however , one C .bracarensis isolate could not be identified and all of the 12 C .nivariensise isolates were identified correctly , with the spectral score varying from 1 .708 to 1 .944 .CONCLUSION It is for the first time to evaluate the perform‐ances of Vitek MS and Bruker MS in identification of the C .glabrata species complex in China and is concluded that the two methods are reliable for the identification of the C .glabrata .Bruker MS is superior to Vitek MS in identification of the rare species of Candida .
Objective To understand the resistance mechanism and epidemic resistance clone of carbopenems antibiotics resistance acinetobacter baumannii ( CRAB ) in Heilongjiang prov-ince by the phenotype test and homology analysis .Methods Modified Hodge test , multi sub-strate multi inhibitor synergy classification detecting carbapenemase ( CHBLs) and PCR ampli-fication of OXA-23 , OXA-24 , OXA-58 , OXA-51 were used to analyze the molecular type and the genetic relationship between resistant strains .Rseults Two hundred and eighty-six strains of the 319 clinical CRAB were positive in modified Hodge test .All the 187 strains produced serine carbapenemase (SCHBLs) with no metal carbapenemase (MCHBLs) found.OXA-51 gene were positive among the 187 CRAB strains , and the positive rate of OXA-23 gene was 98%.None specific bands of OXA-24 and OXA-58 gene were found .Conclusion OXA-23 is the major gene of CRAB prevalent in Heilongjiang area .
Methicillin-resistant Staphylococcus aureus (MRSA) has become an important nosocomial pathogen, causing considerable morbidity and mortality. During the last 20 years, a variety of genotyping methods have been introduced for screening the prevalence of MRSA. In this study, we developed and evaluated an improved approach capillary gel electrophoresis based multilocus variable-number tandem-repeat fingerprinting (CGE/MLVF) for rapid MRSA typing. A total of 42 well-characterized strains and 116 non-repetitive clinical MRSA isolates collected from six hospitals in northeast China between 2009 and 2010 were tested. The results obtained by CGE/MLVF against clinical isolates were compared with traditional MLVF, spa typing, Multilocus sequence typing/ staphylococcal cassette chromosome mec (MLST/SCCmec) and pulse field gel electrophoresis (PFGE). The discriminatory power estimated by Simpson's index of diversity was 0.855 (28 types), 0.855 (28 patterns), 0.623 (11 types), 0.517 (8 types) and 0.854 (28 patterns) for CGE/MLVF, traditional MLVF, spa typing, MLST/SCCmec and PFGE, respectively. All methods tested showed a satisfied concordance in clonal complex level calculated by adjusted Rand's coefficient. CGE/MLVF showed better reproducibility and accuracy than traditional MLVF and PFGE methods. In addition, the CGE/MLVF has potential to produce portable results. In conclusion, CGE/MLVF is a rapid and easy to use MRSA typing method with lower cost, good reproducibility and high discriminatory power for monitoring the outbreak and clonal spread of MRSA isolates.
OBJECTIVES To define the antifungal susceptibility patterns of the most common non-albicans Candida spp. in China. METHODS We evaluated the susceptibilities to nine antifungal drugs of Candida parapsilosis species complex, Candida tropicalis, Candida glabrata species complex and Candida krusei isolates from patients with invasive candidiasis at 11 hospitals over 3 years. Isolates were identified by MALDI-TOF MS supplemented by DNA sequencing. MICs were determined by Sensititre YeastOne(TM) using current clinical breakpoints/epidemiological cut-off values to assign susceptibility (or WT), and by CLSI M44-A2 disc diffusion for fluconazole and voriconazole. RESULTS Of 1072 isolates, 392 (36.6%) were C. parapsilosis species complex. C. tropicalis, C. glabrata species complex and C. krusei comprised 35.4%, 24.3% and 3.7% of the isolates, respectively. Over 99.3% of the isolates were of WT phenotype to amphotericin B and 5-flucytosine. Susceptibility/WT rates to azoles among C. parapsilosis species complex were ≥97.5%. However, 11.6% and 9.5% of C. tropicalis isolates were non-susceptible to fluconazole and voriconazole, respectively (7.1% were resistant to both). Approximately 14.3% of C. glabrata sensu stricto isolates (n = 258) were fluconazole resistant, and 11.6% of C. glabrata sensu stricto isolates were cross-resistant to fluconazole and voriconazole. All C. krusei isolates were susceptible/WT to voriconazole, posaconazole and itraconazole. Overall, 97.7%-100% of isolates were susceptible to caspofungin, micafungin and anidulafungin, but 2.3% of C. glabrata were non-susceptible to anidulafungin. There was no azole/echinocandin co-resistance. Disc diffusion and Sensititre YeastOne(TM) methods showed >95% categorical agreement for fluconazole and voriconazole. CONCLUSIONS In summary, reduced azole susceptibility was seen among C. tropicalis. Resistance to echinocandins was uncommon.
正>为了解临床常见酵母样真菌的种类及对常用抗真菌药物的耐药性,现对哈尔滨医科大学附属第四医院近3年分离出的968株酵母样真菌进行培养鉴定及药敏试验,现将结果报告如下。1材料与方法1.1标本来源2010年1月-2012年12月住院及门诊患者送检的痰、咽拭子、血液、尿液、粪便、脑脊液及各种分泌物等不同类型标本中分离出的968株酵母样真菌。1.2仪器和试剂沙保罗琼脂培养基和科玛嘉显