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Background & objectives: Rampant use of ?-lactam antibiotics in both community and hospitals has transformed the human healthy intestinal gut flora into a reservoir of antibiotic-resistant organisms. This study was conducted to find the faecal presence of antibiotic-resistant Enterobacteriaceae in faecal samples in the community in north India. Methods: In this prospective study, 207 stool samples were collected from apparently healthy individuals residing in a semiurban community in Chandigarh, India, from August to October, 2015. Isolates belonging to family Enterobacteriaceae were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and antibiotic susceptibility was determined using Clinical Laboratory Standard Institute disc diffusion method. Detection of extended spectrum ?-lactamases (TEM, SHV, OXA-1, CTXM 1, CTXM 2, CTXM 9 and CTXM 8/25), carbapenemases (IMP, VIM and KPC) and New Delhi metallo-?-lactamase was done by multiplex PCR. Results: Of the population studied, 55.5 per cent were females and 60 per cent were illiterate or had only primary education; 43.4 per cent individuals were aged <20 yr. Overall, 70.5 per cent of stool samples had antibiotic-resistant isolates. Maximum resistance was seen for cephalosporins (60.4%) followed by fluoroquinolones (41.5%). The multidrug-resistant (MDR) isolates were 2.4 per cent. The most commonly detected genes were TEM, SHV, OXA-1, CTXM-1, CTXM-2, CTXM-9 and CTXM-8/25 ?-lactamases. Escherichia coli was the most common resistant isolate, and TEM was the most common gene detected. Interpretation & conclusions: Overall, 70.5 per cent members of Enterobacteriaceae had antibiotic resistance in the community and 2.4 per cent were MDR. Higher resistance rates were observed for most commonly used drugs such as cephalosporins and fluoroquinolones. High rate of antibiotic-resistant Enterobacteriaceae in gut of healthy individuals points towards the need for active screening and prevention of dissemination.
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Background & objectives: Nosocomial infections caused by multidrug-resistant, Pseudomonas species have become a major clinical and public health concern. The aim of this study was to characterize phenotypic and genotypic profile of antimicrobial resistance (AMR) in Pseudomonas spp. isolated from hospitalized patients. Methods: A total of 126 consecutive, non-duplicate isolates of Pseudomonas spp. isolated from various clinical samples were included in the study over a period of two years. Identification and antimicrobial sensitivity was performed using automated culture system according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. Phenotypic detection of extended-spectrum ?-lactamases (ESBLs), Amp-C ?-lactamase (AmpC) and metallo-?-lactamases (MBLs) were done by various combinations of disc-diffusion and E-test methods, followed by polymerase chain reaction-based detection of ?-lactamase-encoding genes. Results: Among 126 clinical isolates, 121 (96.1%) isolates were identified as Pseudomonas aeruginosa. Most of the isolates were recovered from pus sample, 35 (27.8%) followed by urine, 25 (19.84%); endotracheal aspirate, 24 (19.04%); blood, 14 (11.11%) and sputum, four (3.17%). The highest rate of resistance was against ticarcillin-clavulanic acid, 113 (89.7%) followed by meropenem, 92 (72.5%) and ceftazidime, 91 (72.3%). Overall, ESBLs, AmpC and carbapenemase production was detected in 109 (96.4%), 64 (50.8%) and 105 (94.6%) isolates by phenotypic methods. The most prevalent ESBL gene was blaTEMin 72 (57.1%) and the least prevalent was blaSHVin 19 (15.1%) isolates. AmpC gene was seen less compared to ESBL gene. The most prevalent carbapenemases gene was blaNDM-141 (46.06%) followed by blaVIM and blaOXA-1. Interpretation & conclusions: Our findings suggested that a high rate of ESBLs and carbapenemases production was observed in Pseudomonas spp. Therefore, phenotypic and genotypic detection of AMR needs to be combined for better characterization of resistance patterns in Pseudomonas spp.
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Background & objectives: The increasing prevalence of extended-spectrum ?-lactamases (ESBLs) has abated therapeutic options worldwide. This study was undertaken to investigate the molecular profile and resistance patterns of ESBLs among clinical isolates of Escherichia coli and Klebsiella pneumoniae at four tertiary care centres in India. Methods: Clinical isolates of E. coli and K. pneumoniae were collected from the All India Institute of Medical Sciences (AIIMS), New Delhi; the Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Puducherry; Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh and Christian Medical College (CMC), Vellore, over one and a half year period. Antimicrobial susceptibility was determined by Kirby-Bauer disc diffusion method. ESBLs were confirmed phenotypically, and multiplex PCR was performed to identify genes for ?-lactamases (blaTEM, blaSHV, blaOXA-1, blaCTXM-1, blaCTXM-2, blaCTXM-9 and blaCTXM-15). Results: Among 341 E. coli isolates collected during the study period, 171 (50%) harboured blaTEM, 145 (43%) blaOXA-1,70 (21%) blaCTXM-1, 19 (6%) blaSHV and four (1%) harboured blaCTXM-2. Phenotypically, combined disc test detected ESBL production in 98/298 (33%) E. coli. Among 304 K. pneumoniae isolates, 115 (38%), 89 (29%), 83 (27%), 64 (21%) and two (0.6%) harboured blaTEM, blaOXA-1, blaCTXM-1, blaSHV and blaCTXM-2, respectively. Combined disc test (CDT) detected ESBL production in 42 per cent K. pneumoniae. Most of the blaCTXM-1positive isolates were also blaCTXM-15 positive. The carbapenem susceptibility ranged from 56 to 88 per cent for E. coli and from 20 to 61 per cent for K. pneumoniae. Antibiotic sensitivity patterns showed that colistin (CST) was the most sensitive drug for both E. coli (271/274, 99%) and K. pneumoniae (229/234, 98%). Interpretation & conclusions: The prevalence of ESBL among four study centres varied, and blaTEM, blaOXA-1 and blaCTXM-15 were the most common genotypes in E. coli and K. pneumoniae isolates in India. The growing carbapenem resistance and emerging colistin resistance warrant the judicious use of these antimicrobials.
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Purpose: Sepsis is a significant cause of morbidity and mortality amongst neonates. Klebsiella pneumoniae is a common cause of nosocomial outbreaks causing bacteraemia and having potential of acquiring plasmids enhancing antimicrobial resistance. In the present study, we investigate K. pneumoniae outbreak causing bacteraemia amongst neonates over a span of 2 months. Isolates were characterised for antimicrobial resistance, virulence, molecular typing for clonality and plasmid typing for transmission dynamics, and patient outcome was investigated. Methods: Thirteen isolates of K. pneumoniae were obtained during October–November 2016. Antimicrobial susceptibility testing was performed, and multiplex polymerase chain reaction (PCR) for ?-lactamases and PCR for ompK35 and ompK36 were performed. To study hypervirulence, string test and PCR for rmpA and rmpA2 were performed. Multilocus sequence typing and Inc plasmid typing were carried out to study transmission dynamics. Results: Amongst 13 isolates, all isolates harboured blaSHVand blaTEM; 12 isolates carried blaCTX-M-1. ompK35 was present in all, but ompK36 was absent in 12 isolates. Ten isolates belonged to ST48, 6 amongst which contained IncFII (K) plasmid. One isolate each belonged to ST29, ST111 and ST2647 (novel clone). None of the isolates was hypervirulent. Conclusion: Extended-spectrum ?-lactamase K. pneumoniae is commonly seen in Indian hospitals and main mechanisms being production of SHV, TEM and CTX-M enzymes as seen in the present study. Outer membrane porins contribute significantly to antimicrobial resistance. Emergence of new clones such as ST2647 implies continuous evolution of the organism and also potential for rapid genetic recombination leading to multidrug resistance. Outbreaks amongst neonates lead to fatal outcome, and stringent hospital infection control is necessary.
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ABSTRACT During the last 30 years there has been a dissemination of plasmid-mediated -lactamases in Enterobacteriaceae in Brazil. Extended spectrum -lactamases (ESBL) are widely disseminated in the hospital setting and are detected in a lower frequency in the community setting. Cefotaximases are the most frequently detected ESBL type and Klebsiella pneumoniae is the predominant species among ESBL producers. Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae became widely disseminated in Brazil during the last decade and KPC production is currently the most frequent resistance mechanism (96.2%) in carbapenem resistant K. pneumoniae. To date KPC-2 is the only variant reported in Brazil. Polymyxin B resistance in KPC-2-producing K. pneumoniae has come to an alarming rate of 27.1% in 2015 in São Paulo, the largest city in Brazil. New Delhi metallo--lactamase was detected in Brazil in 2013, has been reported in different Brazilian states but are not widely disseminated. Antimicrobial resistance in Enterobacteriaceae in Brazil is a very serious problem that needs urgent actions which includes both more strict adherence to infection control measures and more judicious use of antimicrobials.
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OBJECTIVE To investigate the produce of extended-spectrum ?-lactamases(ESBLs) and the presence of genotype of the ?-lactamases-encoding genes in Klebsiella pneumoniae isolated from the 98th Hospital of PLA,Huzhou,Zhejiang Province,China.METHODS Twenty-five strains of K.pneumoniae were isolated from the inpatients between Sep 2005 and Apr 2006.ESBLs were tested by phenotypic confirmatory tests recommended by CLSI.Twenty-one kinds of ?-lactamases genes of blaTEM,blaSHV,blaLEN,blaOKP,blaCTX-M-1 group,blaCTX-M-2 group,blaCTX-M-9 group,blaOXA-1 group,blaOXA-2 group,blaOXA-10 group,blCARB,blaPER,blaVEB,blaGES,blaLAP,blaDHA,blaACT/MIR,blaCMY/MOX,blaFOX,blaCMY/LAT,and blaACC were analyzed by PCR and verified by DNA sequencing.RESULTS In 25 strains of K.pneumoniae,the positive,negative,and "uncertainty" rates of ESBLs were 56.0%,20.0%,and 24.0%,respectively.The positive rate of genes of blaTEM,blaSHV,blaCTX-M-1 group,blaOXA-10 group,blaLAP,and blaDHA were 80.0%,4.0%,4.0%,80.0%,4.0% and 32.0%,respectively.The 15 kinds of rest genes were all tested negative.The total positive rate of 21 kinds of ?-lactamases gene was 92.0%.Among them,the blaLAP-2 gene sequence of the HZ12593 strain has been registered in GenBank(GenBank Accession Number: EU529981).CONCLUSIONS There are higher rate of ESBLs-producing strains in K.pneumoniae isolated from the inpatients,and at least 6 kinds of ?-lactamases gene existed.Both genes of blaTEM and blaOXA-10 group are the most common genotypes.Carring blaDHA Gene may influence the result of phenotypic confirmatory test for ESBLs in K.pneumoniae.
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OBJECTIVE To investigate drug-resistance status of Klebsiella pneumoniae(KPN) among oil field staff-workers and provide the evidence for clinical application of antibiotics.METHODS Referring to the National Clinical Laboratory Operation Rules,KPN strains were isolated and identified.The drug-sensitivity testing was performed by K-B methods.The extended-spectrum-?-lactamases(ESBLs) producers were detected by double-disc synergy test and disc confirming test.RESULTS The 276 strains of KPN were mainly isolated from respiratory tract and urinary tract.The isolating rate of ESBLs-producing KPN was 37.0%.The results of susceptibility testing showed the drug-resistance to common antibiotics in ESBLs producers was generally higher than that in ESBLs nonproducer.There was no KPN resistant to imipenem and meropenem.CONCLUSIONS Drug-resistance status of KPN in a oil field hospital is very serious.We should strengthen monitoring and controlling of it.
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OBJECTIVE To evaluate VITEK32 expert system(7.02) for detection and analysis of clinically important resistance phenotypes.METHODS A total of 508 known resistant phenotype clinial strains and 9 standards strains were tested by VITEK32 expert system(7.02) and antibiotic susceptibilities were determined by CLSI recommendation.RESULTS The correct phenotype was identified by the expert system in one or more choices for 312 from the 508(61.4%) isolates and standards.The resistant phenotypes for meticillin-susceptible,and resistant Staphylococcus spp,extended-spectrum ?-lactamases(ESBLs) producingEscherichia coli,Klebsiella spp,AmpC producing Enterobacter,cloacae,Serratia marcescens,and vancomycin-resistant Enterococcus faecalis were accurately identified by VITEK32 expert system,this expert system was not including ESBLs producing Proteus mirabilis.CONCLUSIONS VITEK32 expert system can be accurately identified most clinically important bacteria based on phenotype.The data of ESBLs Producing P.mirabilis should be included in the further work on expert system.
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OBJECTIVE To analyze the drug-resistance of Enterobacter cloacae isolated from clinic in the past two years.METHODS The drug-resistance by K-B method,and to perform 3-D test to detect AmpC ?-lactamase and ESBLs were detected.RESULTS One hundred and six strains of E.cloacae was detected.Burn department were the wards which had the highest detection rate.Sputum,wound,bile and drainage fluid had the highest positive rate.Sensitivity test results showed that the resistance rate to penicilins,Ⅰ,Ⅱ-generation cephalosporins and cefoxitin of E.cloacae was the highest,and the resistance rate to the third,and fourth-generation cephalosporins was 24.5-50.9%.The detection rate of ESBLs and AmpC was 27.4% and 40.6%,respectively.Twenty three strains produced both of them.CONCLUSIONS The detection rate and drug resistance of E.cloacae are increasing severely.Laboratory should pay more attention to their detections and surveillance so as to control hospital infection of E.cloacae.
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MIC.RESULTS The bacteriostatic/bactericidal CFR of 0.5g q8h imipenem/cilastatin and 0.5g q8h meropenem were the highest(100%);that of 3.375g q4h sodium piperacillin/tazobactam sodium against ESBLs-producing E.coli was above 90%;the CFRs of ceftriaxone(1g q24h,2g q24h),ceftazidime(1g q8h,2g q8h),cefepime(1g q8h,1g q12h,2g q8h) and cefoperazone sodium/sulbactam(0.5g q8h,1g q8h,2g q8h) against ESBLs-producing strains were clearly less than those of non-ESBLs-producing ones,and the CFRs could not be effectively improved with the dose and frequency increased.CONCLUSIONS The PK/PD simulation is useful to optimize the regimen of anti-infective treatment,and guide its dosing accurately.
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OBJECTIVE To evaluate the relationships between antimicrobial usage and the isolated rate of ESBLs-KPN and ESBLs-ECO.METHODS We monitored the data on the yearly patient-days and the yearly consumption(defined daily dose(DDD) per 1000 patient days) frequent antibiotics and the isolated rate of ESBLs-KPN and ESBLs-ECO causing nosocomial infections from Jan 2004 to Dec 2007 was analyzed.RESULTS The yearly patient-days of our department significantly increased from 64 203 days in 2004 to 74 442 days in 2007(P
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OBJECTIVE To investigate the drug-resistance status of Klebsiella pneumoniae(KPN) in mountain hospitals and provide the reference for rational application of antibiotics.METHODS Referring to Rules of Operation in Clincal Laboratory of Nationwide,146 KPN isolates were cultured and identified and the drug-sensitivity test was performed in our hospital.RESULTS 100% of KPN isolates were sensitive to imipenem and meropenem.The resistant rates to amikacin,piperacillin/tazobactam,cefoperazone/sulbactam and cefoxitin were all below 22.0%.And that to the other 11 antibiotics were higher and all above 30%.The detection rate of the extended-spectrum-?-lactamases(ESBLs) producing KPN was 28.8%.CONCLUSIONS The drug-resistance of KPN in mountain hospitals is obviously lower than that in general hospitals of developed cities.We should strengthen reasonable management of antibiotics to prevent and control the occurrence and dissemination of drug resistant strains.
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OBJECTIVE To analyze the distribution and drug-resistance of Klebsiella pneumoniae isolated from clinic in the past two years to help doctors to use antibiotic reasonably.METHODS To detect the drug-resistance of 470 strains of K.pneumoniae to 15 kinds of antimicrobial agents were detected by K-B method,and the AmpC ?-lactamase and ESBLs were detected through the way of 3-D test.RESULTS ICU and burn department were found where had the highest isolation rate,and sputum and wound that had the highest detection rate.Sensitivity test results showed that the resistance rate of K.pneumoniae to penicillins,first and second-generation cepholosporins,fluoroquinolones and sulfamethoxazole compound was high(51.1-88.3%),and resistance rate to the third and fourth-generation cephalosporins was high,too(32.6-40.4%).All strains were sensitive to imipenem,but two of them were resistant to meropenem.ESBLs were found in 152 strains,the detection rate was 32.3%,AmpC was found in 29 strains,the detection rate was 6.2%.Both of them were found out in 21 strains.CONCLUSIONS The lower respiratory tract infection is the most common one.The ICU and wound ward are the high-risk places ward of infection.Detection rate and drug resistance are increasingly severe,clinic and laboratory should make concerted efforts to reduce nosocomial infection and strengthen information feedback.
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OBJECTIVE To investigate the prevalence of strains producing extended-spectrum ?-lactamases (ESBLs) and AmpC ?-lactamases in Pseudomonas aeruginosa,and to supply the laboratory evidence for antibiotic rational application in clinic. METHODS Totally 105 clinical isolates of P. aeruginosa were identified with VITEK-32. Drug sensitivities were determined by Kirby-Bauer methods. ESBLs were detected by double-disc synergy test,and cefoxitin three dimensional test was applied to filter AmpC positive strains. RESULTS Among 105 strains of P. aeruginosa,28 strains (26.7%) were AmpC enzymes positive,20 strains (19.0%) were ESBLs positive,and 5 strains(4.8%)were AmpC+ESBLs positive. The detective rate of producing AmpC ?-lactamases strains was higher than that of producing ESBLs strains. There was significant difference between them. CONCLUSIONS ESBLs and AmpC ?-lactamases are two main enzyme types conferring resistance to ?-lactam antibiotics in clinical isolates of P. aeruginosa. Imipenem can be the first choice for treating infections caused by P. aeruginosa producing ESBLs or AmpC ?-lactamases.
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OBJECTIVE To investigate the genotype distribution in extended-spectrum ?-lactamases-producing Escherichia coli in our hospital.METHODS Clinical strains of E.coli confirmed to produce ESBLs were collected from our hospital.ESBLs genotype was analyzed by plasmid conjugation,PCR and nucleotide sequencing analysis.RESULTS The susceptiblility rate of ESBLs-producing strains were 100% to imipenem,75.4% to piperacillin/tazobactam.A total of 4 genotypes were identified in the 28 ESBLs-producing strains.CTX-M type was identified in 92.9% of the strains,including CTX-M-14,CTX-M-24 and CTX-M-3.SHV Type was identified in 7.1% of the strains,including SHV-12.CONCLUSIONS ESBLs producers are common in E.coli isolated from our hospital.Most of them are multidrug resistant and CTX-M is the main genotype of ESBLs.Other genotypes of ESBLs are not found.
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OBJECTIVE To investigate the drug-resistance status of Escherichia coli(ECO)from various kinds of specimens to provide the scientific evidence for reasonable use of antibiotics.METHODS ECO strains were isolated and identified according to the National Clinical Laboratory Operation Rules.Drug resistance profile was analyzed by K-B method recommended by CLSI.RESULTS Among 275 ECO strains,50.2%(the most highest isolating rate)were isolated from urine.Detection rate of extended spectrum ?-lactamases(ESBLs)producing ECO was 32.4%(89/275).Except for 100% susceptibility to carbopenems,the drug-resistance to 14 antibiotics in ESBLs producers was higher than in the nonproducers.CONCLUSIONS Laboratory department should think highly of the monitoring of ECO to prevent and control the occurrence and prevalence of the nosocomial infection with ECO.
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OBJECTIVE To analyze the situation of extended spectrum ?-lactamases(ESBLs)and AmpC enzyme produced by nosocomial Escherichia coli isolates in 2005-2007.METHODS ESBLs were detected by double disk synergy test and disk diffusion confirmatory test.AmpC enzyme was detected by the three dimensional assay.Chi square test was used to test the significance.The application of different kinds of antimicrobials before the results of etiology be presented and the resistence rate of the ESBLs both producing and no producing were compared respectively.RESULTS The detectable rate of ESBLs in E.coli isolates of nosocomial and community infection was 55.1% and 21.3% and the detectable rate of AmpC enzyme nosocomial E.coli isolates was 17.4%.All strains were 100% susceptible to meropenem and imipenem but resistant to 15 other antimicrobials in different degree.The sensitivity to Piperacillin/tazobactam,cefoperazone/sulbactam and amikacin were relatively high.CONCLUSIONS The carrying rate of ESBLs from nosocomial E.coli isolates is high and AmpC enzyme and other resistance genes,which lead to multiple drug resistance.Standardized management of antimicrobials application should be strengthened and the consciousness of rational antimicrobials utilization should be raised.
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OBJECTIVE To investigate the drug resistance and the status of producing ESBLs and AmpC beta-lactamases of Klebsiella pneumoniae isolates from 2006 to 2007 in local district.METHODS From 2006 to 2007,110 strains of K.pneumoniae insensitive to cefoxitin were collected.The sensitiveness to 16 antibiotics were tested by K-B method and microdilution method.Genes of TEM,SHV,GES,PER,CTX-M-1,CTX-M-2,CTX-M-3,DHA and MIR-1/ACT-1 were tested by PCR.The gene transfer was detected by conjugation test.RESULTS The resistance rate of 110 K.pneumoniae strains to meropenem,imipenem,piperacillin/tazobactam,cefoperazone/sulbactam,ceftazidime and cefepime was 0-49.9%.The resistance rate to other antibiotics was 80-100%.And ESBLs production was the main result.Genes of ESBLs were CTX-M and SHV.Genes of AmpC beta-lactamases were ACT and DHA.They all could transfer the drug-resistance from plasmid to receptor bacteria.CONCLUSIONS Co-existing of ESBLs and AmpC beta-lactamases is the main reason of multi-drug resistance that K.pneumoniae.Transferring of drug-resistance gene leads to the spreading of drug-resistance.The drug-resistance rate of K.pneumoniae decreased during the last two years.
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OBJECTIVE To investigate the drug resistance of ESBLs-producing Escherichia coli and Klebsiella pneumoniae in local nosocomial infection,for guiding the clinical drug resistance. METHODS ATB analysis system was used for identification of bacteria,extra-susceptibility tests were detected by K-B method. RESULTS The isolation rate of ESBLs-producing E. coli and the K. pneumoniae was 29.9% and 30.8%,respectively. The drug susceptibility was indicated the resistance rate of ESBLs producing strains to antibacterial agents except imipenem was higher than that of non-ESBLs producing strains. CONCLUSIONS Detecting drug resistance of ESBLs producing strains is of important significance for guiding the clinical rational use of antibacterials and controling the epidemics.
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OBJECTIVE To investigate the distribution and drug resistance of strains producing extended spectrum beta-lactamases (ESBLs) isolated from clinic samples and offer scientific basis for reasonable usage of antibioticsMETHODS ESBLs-producing strains isolated from Escherichia coli were identified by phenotypic comfirmatory test,drug resistance was analyzed by K-B method. RESULTS The positive rate of isolated ESBLs-producing E. coli strains was respectively 18.0%,20.3% and 28.4% in three years; that of ESBLs-producing strains isolated from urinary system was respectively 25.6%,29.0% and 39.0% in three years. The susceptibility to AMK and CFS was 70.4% and 85.2%,respectively in 2006. CONCLUSIONS The positive rate of ESBLs-producing strains and their resistance have been increasing in the near three years. so our clinic should pay attention to reasonable usage of antibiotic. AMK and CFS show significant antimicrobial activity for ESBLs-producing E. coli.