Appendical Perforation by Infection with Extended-Spectrum Beta-Lactamase (ESBL)-Producing <i>Escherichia coli</i>: Case Report

We report the very rare case of a huge appendical abscess with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) as the pathogen. There have been several reports of appendical infections such as appendicitis and appendical abscess caused by ESBL-producing bacteria in adults. The treatment of ESBL-producing E. coli infection is specific, and ESBL-producing bacteria have recently been reported as pathogens associated appendicitis in children. To the best of our knowledge, this is the second report of perforated appendicitis with abscess due to ESBL-producing E. coli. We discuss the diagnostic modalities and treatments for appendical abscess with ESBL-producing E. coli. and propose that the patients with perforated appendicitis and abscess formation due to ESBL-producing E. coli should be administered the antibiotic MEPM within 2 weeks to treat the abscess more effec-tively without producing other multidrug-resistant bacteria.

Diagnostic Validity of Cica Beta Test 1 for the Detection of Extended Spectrum Beta-Lactamase (ESBL) Producing Gram Negative Bacteria by Comparing with Phenotypic Method

Background: Detection of extended spectrum beta lactamase producing bacteria is an important issue in the clinical settings. Objective: The purpose of the present study was to validate the Cica Beta Test 1 for detection of extended spectrum beta-lactamase (ESBL) producing bacteria. Method: This analytical type of cross-sectional study was carried out in the Department of Microbiology and Immunology at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from January 2006 to December 2006 for a period of one (01) year. All the patients presented with the clinical features of urinary tract infection and surgical as well as burn wound infection at any age with both sexes were selected as study population. All bacteria were isolated and identified by their colony morphology, staining characters, pigment production, motility and other relevant biochemical tests. Phenotypic confirmation of ESBLs producing isolates were done by inhibitor potentiated disc diffusion test according to CLSI recommendation. The Cica Beta Test 1 was performed according to the manufacturer’s instructions. Result: A total number of 288 Gram negative bacteria were isolated. Among these isolates Cica Beta test 1 was positive in 97 strains and phenotypic confirmatory test was positive in 89 strains. The test sensitivity of Cica Beta Test 1 was 100% (95% CI 95.9% to 100.0%). Specificity of the test was 96.0% (95% CI 92.2% to 98.2%). The positive predictive value (PPV) and negative predictive value (NPV) were 92.7% (95% CI 84.5% to 95.7%) and 100.0% (95% CI 98.0% to 100.0%) respectively. The accuracy of the test was 97.2% (95% CI 95.1% to 99.1%). Area under ROC curve = 0.980 (95% CI 0.964 to 0.996);p value 0.0001. Conclusion: In conclusion, Cica Beta Test 1 is very high sensitivity and specificity for the detection of ESBL from Gram negative bacteria.

鸭大肠杆菌超广谱β-内酰胺酶检测(ESBLs)及药物敏感性测定

对国内7个省份临床分离的32株鸭大肠杆菌进行超广谱β-内酰胺酶(ESBLs)检测及药物敏感性研究。结果表明,32株分离的鸭大肠杆菌中产ESBLs菌株7株,阳性检出率为21.87%;产ESBLs菌株对常用头孢三代及半合成青霉素类药物的敏感率低于42.9%,耐药率则高于28.6%,对阿莫西林、氨苄西林、头孢噻呋的耐药率高达100%。产酶菌株和非产酶菌株对新型头孢四代产品头孢吡肟及碳青霉烯类药物亚胺培南、美罗培南的敏感率高于96%。加酶抑制剂的β-内酰胺类抗生素如阿莫西林/棒酸、氨苄西林/舒巴坦、头孢哌酮/舒巴坦等对产酶菌株和非产酶菌株的敏感率全部高于未加酶抑制剂的单方药物。产ESBLs菌株存在多重耐药现象,酶抑制剂能够部分解决此类耐药性问题。

下呼吸道感染产ESBLs肺炎克雷伯菌基因型分析

目的了解引起下呼吸道感染产 ESBLs 肺炎克雷伯菌的耐药性及 ESBLs 和 AmpC 基因型,指导临床合理用药。方法收集产 ESBLs 肺炎克雷伯菌36株。用纸片扩散法进行药敏性试验,表型筛选法检测出同时产 AmpC 酶的菌株,PCR 法检测 ESBLs 和 AmpC 酶的基因型。结果产 ESBLs 肺炎克雷伯菌对亚胺培南和美罗培南全部敏感,对所测试的其他药物呈不同程度耐药。36株产 ESBLs 肺炎克雷伯菌中,20株扩增出 CTX-M-Ⅲ群基因,15株扩增出 TEM 基因,SHV 和 OXA 基因各1株,ACT-1(MIR-1)和 DHA-1(DHA-2)各4株,12株细菌同时携带2种以上的基因型。结论本院下呼吸道感染患者中分离的产 ESBLs 肺炎克雷伯菌主要携带 CTX-M 和 TEM 基因型,少数携带 ACT、DHA、SHV 和 OXA 基因型,可介导对β内酰胺类药物的耐药。本研究未对 TEM 和 SHV 基因型作进一步分析。

禽致病菌ESBLs和AmpC酶的检测及药敏分析

用全自动微生物鉴定系统(VITEK-32)鉴定了禽分离致病菌,分别进行了β-内酰胺酶(BLA)、超广谱β-内酰胺酶(ESBLs)、AmpC酶的检测,并用试管两倍稀释法测定了各种抗生素对非产酶菌、产ESBLs菌及产AmpC菌的抗菌活性。结果表明,鉴定分离的20株致病菌有大肠埃希菌15株、阴沟肠杆菌1株、铜绿假单胞菌1株、法氏柠檬酸杆菌1株、肺炎克雷伯菌1株及鹑鸡肠球菌1株,其中法氏柠檬酸杆菌、肺炎克雷伯菌及鹑鸡肠球菌系兽医上首次检出。报道所分离的20株致病菌均产β-内酰胺酶,其中产ESBLs 9株,同时产ESBLs和AmpC酶1株。产酶菌株对抗生素的耐药性严重,而抗生素/抑制剂联用能降低药物对细菌的MICs。

产ESBLs肺炎克雷伯菌的致病性及头孢他啶疗效分析

目的探讨产ESBLs肺炎克雷伯菌不同感染途径的致病性差异及头孢他啶对产ESBLs肺炎克雷伯菌腹腔感染小鼠的保护作用。方法分别采用滴鼻途径建立小鼠呼吸道感染模型和腹腔注射途径建立小鼠腹腔感染模型,将小鼠分成6组,检测产ESBLs肺炎克雷伯菌对小鼠的半数致死量。另将头孢他啶体外药敏试验敏感的产ESBLs肺炎克雷伯菌腹腔感染小鼠分成3组,采用不同治疗方法考察头孢他啶的体内治疗作用,同时与亚胺培南/西司他丁钠疗效做对比分析。结果产ESBLs肺炎克雷伯菌经过滴鼻途径感染小鼠未见死亡,经腹腔感染途径的半数致死量为105;头孢他啶预防给药组小鼠的死亡率为10%,同时给药与感染4h后给药组小鼠的死亡率为30%,头孢他啶对产ESBLs肺炎克雷伯菌腹腔感染小鼠的保护作用与亚胺培南/西司他丁钠作用一致。结论产ESBLs肺炎克雷伯菌经呼吸道感染途径的致病性比腹腔感染途径弱,头孢他啶体外药敏试验敏感的产ESBLs肺炎克雷伯菌感染可以采用头孢他啶治疗,但应尽早使用。

产ESBLs肺炎克雷伯菌基因型分析

目的分析肺炎克雷伯菌临床分离株产超广谱β-内酰胺酶(ESBL s)的主要基因型。方法用表型确定的临床分离产ESBL s的肺炎克雷伯菌34株,分别用TEM,SHV,CTX-M-1,CTX-M-2和CTX-M-9扩增引物进行聚合酶链反应(PCR)扩增,并对PCR产物进行序列分析。结果PCR扩增结果显示TEM,SHV,CTX-M-1,CTX-M-2和CTX-M 9的阳性率分别为47.06%,85.29%,26.47%,32.35%和52.94%,CTX-M型总阳性率为88.24%,序列分析证实扩增为目的产物。结论34株ESBL s肺炎克雷伯菌的主要基因型是CTX-M型和SHV型,且同时携带2种以上基因的菌株占所测菌株的82.35%,需引起临床的高度重视。

产ESBLs大肠埃希菌基因型分析

目的分析大肠埃希菌临床分离株产超广谱β-内酰胺酶(ESBLs)的主要基因型。方法用表型确定的临床分离产ESBLs的大肠埃希菌47株,分别用TEM、SHV、CTX-M-1、CTX-M-2和CTX-M-9扩增引物进行聚合酶链反应(PCR)扩增,并对PCR产物进行序列分析。结果PCR扩增结果显示TEM、SHV、CTX-M-1、CTX-M-2和CTX-M-9的阳性率分别为59.57%、4.26%、17.02%、19.15%和82.98%,CTX-M型总阳性率为93.62%,序列分析证实扩增为目的产物。结论47株ESBLs大肠埃希菌的主要基因型是CTX-M型和TEM型,且同时携带2种以上基因的菌株占所测菌株的63.83%,需引起临床的高度重视。

头孢菌素对产ESBLs肺炎克雷白杆菌的抗菌活性研究

目的探讨头孢他啶和头孢噻肟钠体内外抗产超广谱β-内酰胺酶(ESBLs)肺炎克雷白杆菌的效果。方法采用K-B法和仪器法对确认为产ESBLs的肺炎克雷白杆菌进行药敏试验,并选择两株体外药敏结果不同的产ESBLs的肺炎克雷白杆菌建立小鼠腹腔感染模型,同时用头孢他啶和头孢噻肟钠对感染小鼠进行治疗。结果产ESBLs的肺炎克雷白杆菌对头孢他啶的耐药率明显低于其他头孢菌素类药物(均P<0.05),头孢他啶对药敏试验敏感的产ESBLs肺炎克雷白杆菌腹腔感染小鼠保护率为90.0%,头孢他啶和头孢噻肟钠对药敏试验耐药的产ESBLs的肺炎克雷白杆菌腹腔感染小鼠保护率为0。结论头孢菌素类抗菌药物的体内外抗产ESBLs肺炎克雷白杆菌作用基本一致,头孢他啶可以作为亚胺培南/西司他丁钠的替代品治疗产ESBLs肺炎克雷白杆菌感染。

头孢拉宗等9种抗菌药物对产ESBLs大肠埃希菌和肺炎克雷伯菌的体外抗菌活性研究

目的:对比研究头孢拉宗等9种抗菌药物对产超广谱β-内酰胺酶(ESBLs)大肠埃希菌以及肺炎克雷伯菌的体外抗菌活性。方法:采用琼脂平板二倍稀释法测定头孢拉宗等9种抗菌药物对临床分离的产ESBLs大肠埃希菌115株、肺炎克雷伯菌30株的最低抑菌浓度(MIC)。结果:产ESBLs大肠埃希菌和肺炎克雷伯菌对亚胺培南/西司他丁(100%和96.7%)、美罗培南的敏感率最高(100%和96.7%),对头孢拉宗(98.3%和93.3%)、头孢美唑(93.0%和96.7%)和阿米卡星(95.7%和96.7%)的敏感率较高,对哌拉西林/他唑巴坦(92.1%和60.0%)、头孢他啶(62.6%和73.3%)比较敏感,但对头孢噻肟(3.5%和0)、头孢哌酮/舒巴坦(43.5%和36.7%)的耐药率很高。结论:头孢拉宗对产ESBLs的大肠埃希菌和肺炎克雷伯菌均有很强的体外抗菌活性。

ESBLs在大肠埃希菌、肺炎克雷伯菌和阴沟肠杆菌中的检出率及耐药情况比较

目的分析并对比ESBLs（超广谱内酰胺酶）在大肠埃希菌、阴沟肠杆菌以及肺炎克雷伯菌中的检出率、耐药情况。方法以我院2011年6月~2015年9月间内科收治的106例化脓性胆管炎患者为临床研究对象,分别记录其胆汁大肠埃希菌、阴沟肠杆菌以及肺炎克雷伯菌的培养结果,并通过药敏测定和试验检查ESBLs在各类菌种中的耐药情况。结果在154株实验培养菌中,共有62株产ESBLs株,其总检出率为40.3%。而在62株产ESBLs株中,大肠埃希菌检出33株（53.2%）,阴沟肠杆菌检出8株（22.2%）,肺炎克雷伯菌检出21株（37.5%）。大肠埃希菌、肺炎克雷伯菌的检出率要明显高于阴沟肠杆菌,x12=22.77,其对比均具有统计学意义（P〈0.05）;肺炎克雷伯菌的检出率要明显高于阴沟肠杆菌,x22=7.61,其对比有统计学学意义（P〈0.05）。在各类标本中,在胆管结石病例胆汁培养结果中,产ESBLs肺炎克雷伯菌（85.7%）的检出数量最高;在胆管恶性梗阻病例中,产ESBLs阴沟肠杆菌、大肠埃希菌所占比例较高。产ESBLs阴沟肠杆菌、大肠埃希菌和肺炎克雷伯菌均对阿莫西林耐药,且耐药率为100%;3种菌株对头孢类抗菌药耐药率较高,3种菌株对碳青霉烯类耐药率比较低。产ESBLs阴沟肠杆菌的耐药率要低于产ESBLs大肠埃希菌和肺炎克雷伯菌,特别是在庆大霉素、环丙沙星以及头孢类药物上差距最为明显。结论对于产ESBLs（超广谱内酰胺酶）菌株导致的感染疾病,结合药敏试验的结果来合理选择抗生素用药,是延滞细菌耐药性出现的关键,也是临床合理用药的重要保证。

产ESBLs及AmpC大肠埃希菌耐药性分析

目的 调查对头孢菌素耐药的大肠埃希菌的耐药机制及对15种抗生素的耐药性与耐药特点。方法 对华中科技大学同济医学院附属同济医院检验科2004年1～12月临床分离的468株大肠埃希菌采用琼脂二倍稀释法测定15种抗生素的最低抑菌浓度（MIC），标准纸片扩散法检测超广谱G-内酰胺酶（ESBLs），改良三维试验检测头孢菌素酶（AmpC）。结果 468株大肠埃希菌中检出ESBLs153株，检出率32．7％（153／468），AmpC酶7株，检出率1．5％（7／468）。产ESBLs大肠埃希菌对二代头孢耐药率大于90％，对三代头孢耐药率为30．4％（头孢他啶）和55．4％（头孢噻肟），对四代头孢（头孢吡肟）耐药率为58．9％，对酶抑制剂联合制剂阿莫西林／克拉维酸和头孢哌酮／舒巴坦的耐药率为92．9％和80．4％，对环丙沙星的耐药率为83％，对庆大霉素的耐药率为73．3％，对四环素的耐药率为88％。产AmpC酶大肠埃希菌表现出更高的耐药性，对二、三代头孢、四环素、环丙沙星和庆大霉素100％耐药，对四代头孢（头孢吡肟）的耐药率达71．4％，对酶抑制剂联合制剂阿莫西林／克拉维酸和头孢哌酮／舒巴坦的耐药率为100％和71．4％，对单环酰胺类的氨曲南耐药率为85．7％。非产ESBLs和AmpC大肠埃希菌的耐药率明显低于产酶者，碳青霉烯类的亚胺培南对所有测试菌株的耐药率为0，MIC50为0．5mg／L。结论 （1）对头孢菌素耐药的大肠埃希菌的耐药机制主要是产生ESBLs。（2）产AmpC酶大肠埃希菌比ESBLs耐药更严重，仅亚胺培南对其有效。（3）在临床抗感染治疗中应依据药物敏感试验合理选择抗生素，尽量少选具有诱导细菌产酶的抗生素。

Near Future Perspective of ESBL-Producing Klebsiella pneumoniae Strains Using Mathematical Modeling

While antibiotic resistance is becoming increasingly serious today,there is almost no doubt that more challenging times await us in the future.Resistant microorganisms have increased in the past decades leading to limited treatment options,along with higher morbidity and mortality.Klebsiella pneumoniae is one of the significant microorganisms causing major public health problems by acquiring resistance to antibiotics and acting as an opportunistic pathogen of healthcare-associated infections.The production of extended spectrumbeta-lactamases(ESBL)is one of the resistance mechanisms of K.pneumoniae against antibiotics.In this study,the future clinical situation of ESBL-producing K.pneumoniae was investigated in order to reflect the future scenarios to understand the severity of the issue and to determine critical points to prevent the spread of the ESBL-producing strain.For evaluation purposes,SIS-type mathematical modeling was used with retrospective medical data from the period from 2016 to 2019.Stability of the disease-free equilibrium and basic reproduction ratios were calculated.Numerical simulation of the SISmodel was conducted to describe the dynamics of non-ESBL and ESBL-producing K.pneumoniae.In order to determine the most impactful parameter on the basic reproduction ratio,sensitivity analysis was performed.A study on mathematical modeling using data on ESBL-producing K.pneumoniae strains has not previously been performed in any health institution in Northern Cyprus,and the efficiency of the parameters determining the spread of the relevant strains has not been investigated.Through this study,the spread of ESBL-producing K.pneumoniae in a hospital environment was evaluated using a different approach.According to the study,in approximately seventy months,ESBL-producing K.pneumoniae strains will exceed non-ESBL K.pneumoniae strains.As a result,the analyses showed that hospital admissions and people infected with non-ESBL or ESBL-producing K.pneumoniae have the highest rate of spreading the infections.In addition,it was observed that the use of antibiotics plays a major role in the spread of ESBL-producing K.pneumoniae compared to other risk factors such as in-hospital transmissions.As amatter of course,recoveries fromKlebsiella infections were seen to be the most effective way of limiting the spread.It can be concluded from the results that although the use of antibiotics is one of themost effective factors in the development of the increasing ESBL-producing K.pneumoniae,regulation of antibiotic use policy could be a remedial step together with effective infection control measures.Such steps may hopefully lead to decreased morbidity and mortality rates as well as improved medical costs.

重新认识氨曲南在产ESBLs大肠埃希菌感染中的治疗地位

目的探讨氨曲南对产ESBLs大肠埃希菌所致感染的疗效。方法临床药师参与1例氨曲南敏感的产ESBLs大肠埃希菌引起脓毒症的抗感染治疗全过程,进行用药分析与干预。结果患者使用氨曲南治疗产ESBLs大肠埃希菌引起的脓毒症效果良好。结论并非所有产ESBLs肠杆菌科细菌感染都必须选择碳青霉烯类,部分患者可根据药敏结合患者病情选择性使用氨曲南。

Antimicrobial Resistance and β-Lactamase Production among Hospital Dumpsite Isolates

Metallo-β-Lactamases (MBLs) and Extended Spectrum β-Lactamses (ESBLs) have emerged world-wide as a significant source of β-lactam resistance. The emergence of MBLs and ESBLs encoded on plasmids among Gram-negative pathogens in hospital dumpsites was investigated. Soils of different government and private hospitals were collected and processed following standard bacteriological techniques. Antimicrobial susceptibility testing was carried out by the disk-diffusion technique using Ceftazidime (30 μg), Cefuroxime (30 μg), Cefotaxime (30 μg), Cefixime (5 μg), Trimethprim-sulfamethoxazole (25 μg), Gentamycin (100 μg) Amoxicillin-Clavunalate (30 μg), Ciprofloxacin (5 μg), Ofloxacin (5 μg), Nitrofurantoin (300 μg) and Imipenem (10 μg). The role of plasmids in resistance was evaluated by subjecting isolates to curing using Sodium Dodecyl Sulfate (SDS). ESBLs production by Double-Disk Synergy Test (DDST) was carried out. Isolates resistant to Imipenem were subjected to a confirmatory test using Modified Hodge’s test and to MBLs production by DDST. Eighty-two Gram-negative isolates comprising of 32 (39.02%) Escherichia coli, 20 (24.39%) Serratia marcescens, 14 (17.07%) Klebsiella pneumonia, 10 (12.28%) Proteus mirabilis and 6 (7.32%) Enterobacter aerogenes were obtained. Susceptibility results revealed a 100% resistance of all isolates to Ceftazidime, Cefuroxime, Cefixime, Amoxycillin-clavulanate and Cefotaxime. A total of 66 (80.48%) isolates harboured plasmids out of which 26 (31.71%) isolates were ESBL producers. MBLs production was observed in 8 (25.00%) E. coli, 2 (2.41%) Klebsiella pneumonia and 2 (2.41%) Proteus mirabilis isolates. All MBLs producing isolates were ESBLs producers. The finding of highly resistant isolates producing ESBLs and MBLs in a hospital environment is quite disturbing and should be addressed urgently.

多重耐药阴沟肠杆菌β-内酰胺酶编码基因的研究

目的 了解北京朝阳医院临床分离的多重耐药阴沟肠杆菌的 β-内酰胺酶编码基因。方法 对 12株临床分离的多重耐药的阴沟肠杆菌进行琼脂稀释法药敏试验、改良三维试验法和聚合酶链反应克隆测序。结果 12株阴沟肠杆菌对多种抗生素耐药 ,改良三维试验法证实同时产生 Am p C酶和 ESBL s;其中 ,9株 ESBL s编码基因PCR结果阳性 ,分别为 SHV- 2、SHV- 12、CTX- M- 3和 CTX- M- 14型 ESBL s;对另外 3株进行粗酶等电点测定发现 ,存在 7.89和 8.0等电点条带 ,并被克拉维酸抑制 ;12株细菌 am p D和 amp C基因 PCR扩增均呈阳性 ,将 6株耐药菌进行 amp D基因的克隆测序发现均存在羧基端可疑的突变位点。结论 12株多重耐药的阴沟肠杆菌同时产生≥ 1种的 ESBL s及高产 Am p C酶。

产超广谱β-内酰胺酶阳性率及药物敏感试验

目的 了解本地区革兰阴性 (G- )菌超广谱 β-内酰胺酶 (ESBL s)的产生情况及其临床分布 ,指导临床医生合理使用抗生素 ,防止医院感染及产 ESBL s细菌的暴发流行。方法 用 Micro Scan W/ A- 4 0细菌分析系统对分离菌株进行鉴定 ,用纸片扩散法对分离的 G-菌进行 ESBL s确证试验。结果 在所有 4 36株 G-菌中 ,ESBL s总的检出率为 17.2 % ,主要见于大肠埃希菌 2 7.9%、肺炎克雷伯菌 2 5 .7%、阴沟肠杆菌 11.9%、产酸克雷伯菌8.3% ;各病区 ESBL s细菌的检出率以重症监护病房 (ICU)最高 (2 7.4 % ) ,其次为呼吸科病房 (2 2 .7% )和肾内科病房 (18.3% ) ;在各种标本中 ESBL s的检出率以痰标本最高 ,其次为尿液标本 ;ESBL s细菌对亚胺培南的敏感率最高 (10 0 % ) ,其次为哌拉西林 /他唑巴坦。结论 ESBL s总的检出率为 17.2 % ,以大肠埃希菌为主 ;重症监护病房、呼吸科病房是 ESBL s细菌的高发病房 ;ESBL s细菌广泛耐药 ,其治疗以亚胺培南为首选 ,其次为大剂量的哌拉西林 /他唑巴坦。

产超广谱β-内酰胺酶大肠埃希菌和肺炎克雷伯菌的分布及耐药性分析

目的了解医院产超广谱β-内酰胺酶（ESBLs）大肠埃希菌和肺炎克雷伯菌的分布及耐药性特点。方法对我院2004年7月～2006年7月间各类临床标本分离出的大肠埃希菌307株和肺炎克雷伯菌202株，用CLSI／NCCLS推荐的表型确证法检测其ESBLs，采用K-B纸片琼脂扩散法进行药敏试验，分析产ESBLs菌株的分布及耐药性。结果大肠埃希菌和肺炎克雷伯菌产ESBLS菌株的检出率分别为38．4％（118／307）和31．7％（64／202），主要分布于尿和痰、咽拭子中，病区主要集中于肺科、神经外科、感染科、泌尿外科、ICU室。产ESBLs菌株对亚胺培南和美罗培南呈高度敏感，对哌托西林／三唑巴坦、头孢哌酮／舒巴坦、头孢西丁耐药率较低，对其他抗菌药物均出现较高耐药。结论产ESBLS的大肠埃希菌和肺炎克雷伯菌分布在不同病区的不同标本中，碳青霉烯类抗生素亚胺培南和美罗培南是治疗产ESBLS菌株感染的较佳药物。

下呼吸道铜绿假单胞菌超广谱β-内酰胺酶、AmpC酶的检测及意义

目的研究下呼吸道铜绿假单胞菌的主要耐药机制超广谱β-内酰胺酶(ESBLs)和AmpC酶的产生情况。方法采用K-B试验,选用5种药敏纸片(IPM、CTX、CAZ、CTX/CLAV、CAZ/CLAV),参照相关标准,根据抑菌环特征推测ESBLs、AmpC酶的产生。结果114株下呼吸道铜绿假单胞菌中检出产ESBLs菌10株(8.8%),如果仅以CTX/CTX/CLAV为底物,检出7株(6.1%),以CAZ/CAZ/CLAV为底物检出5株(4.4%);产AmpC酶菌79株(69.5%);同时产ESBLs和AmpC酶菌4株(3.5%),产AmpC酶菌的检出率明显高于产ESBLs菌,差别具有显著性(P<0.05)。结论联合CTX/CTX/CLAV和CAZ/CAZ/CLAV两组底物可以提高铜绿假单胞菌ESBLs的检出率;下呼吸道铜绿假单胞菌AmpC酶产生率高,ESBLs产生率低;AmpC酶可能是下呼吸道铜绿假单胞菌对β-内酰胺类抗生素耐药的主要机制。

肠杆菌科细菌中产超广谱β-内酰胺酶菌株的检测及药敏分析

目的了解瑞金医院产ESBLs菌株的发生率,初筛试验与确证试验的符合率以及ESBL菌株的耐药情况。方法按照NCCLS标准用纸片扩散法进行初筛实验和确证实验,用Whonet5软件处理实验数据。结果初筛阳性为55株,用确证试验证实其中52株为产ESBLs菌株,2株肺炎克雷伯氏菌同时产AmpC酶,不能用确证实验检测到,可通过阿莫西林/克拉维酸与头孢吡肟的协同现象予以检测。产ESBLs菌株的发生率:大肠埃希氏菌33株(25.4%),肺炎克雷伯氏菌21株(28.5%)。结论本院流行的产ESBLs菌对头孢噻肟的水解能力很强,部分产ESBLs菌株对头孢吡肟和头孢他啶不敏感。ESBLs产生菌对阿米卡星、庆大霉素和环丙沙星有很高的耐药率,分别为37.0%、68.5%和64.8%,亚胺培南和美罗培南对ESBL产生菌的敏感率为100%。