Frequency Of Extended-spectrum Beta-lactamase Research Articles

Molecular Analysis of Fosfomycin Resistance Among Escherichia coli Isolates from Urinary Tract Infections in Kidney Transplant Patients During 2019 - 2020

Background: This study aimed to estimate the prevalence of fosfomycin resistance and the frequency of extended-spectrum beta-lactamase (ESBL) production in Escherichia coli isolates from three kidney transplant patients (KTPs) in Tehran. Methods: Sixty clinical isolates of uropathogenic E. coli were collected from three kidney transplant centers in Tehran between April and May 2019. Antimicrobial susceptibility testing (AST), minimum inhibitory concentration (MIC) of fosfomycin, and screening for ESBL production were conducted following the protocols established by the Clinical and Laboratory Standards Institute (CLSI). The presence of the blaTEM, blaSHV, blaCTX-M, fosA3, and fosC2 genes was evaluated using polymerase chain reaction (PCR) and sequencing. Additionally, mutations in the murA, glpT, uhpT, and cya genes were assessed. The activity of the carbohydrate phosphate transporter was measured using the real-time PCR assay. Results: According to the AST results, ampicillin showed the highest resistance rate (86%), while ertapenem and doripenem exhibited complete susceptibility (100%). According to the E-test, 1.6% of E. coli isolates were resistant to fosfomycin. Furthermore, 33.4% of E. coli isolates in KTPs were ESBL producers, with the most frequent occurrence of the blaTEM gene (55%). Additionally, mutations were identified in the murA, uhpT, and glpT genes of resistant samples. No plasmid genes for fosA3 and fosC2 were detected. The expression of the uhpT gene increased 32-fold in a susceptible isolate, as determined by qPCR. Conclusions: The high resistance of E. coli isolates from urinary tract infections (UTIs) of KTPs to β-lactam antibiotics remains a significant clinical challenge. However, no correlation was found between ESBL production and resistance to fosfomycin. The resistance rate to fosfomycin was low, and the primary cause of resistance was mutations in chromosomal genes.

Frequency of Extended-Spectrum Beta-Lactamases-Producing Escherichia coli Among Out- and In-patients in Rafsanjan City, Iran

Background: The frequency of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains among clinical isolates has been steadily increasing, leading to limited treatment options. Objectives: This study aimed to assess the antibiotic sensitivity of E. coli and the frequency of ESBL isolates among both out-patients and in-patients. Methods: A total of 390 E. coli isolates were received at the Ali-Ebn-e-Abitaleb Hospital laboratory in Rafsanjan. The antibiogram, as well as the phenotypic and genotypic detection of ESBL isolates, were conducted using Kirby-Bauer, combination disk confirmatory, and polymerase chain reaction tests, respectively. Results: Of all the E. coli isolates, 45.6% exhibited ESBL production. Among these isolates, 46.1% were obtained from hospital wards, while 42.5% were from outpatients. Meropenem and imipenem displayed sensitivities of 97.2% and 93.3%, respectively, whereas amikacin and nitrofurantoin showed sensitivities of 89.7% and 85.6%, respectively, for all isolates. Notably, ceftriaxone, cefotaxime, cefixime, ampicillin, co-trimoxazole, and nalidixic acid demonstrated high resistance rates, surpassing 50%. ESBL-producing isolates were more frequently observed in blood samples (65%) and wounds (60%) compared to other tested isolates. Approximately 8.6% of isolates carried a single type of ESBL gene, while 38.5% carried multiple ESBL genes. Conclusions: The data indicate a prevalence of ESBL-producing E. coli isolates among both out-patients and in-patients, with some of them acquiring two or three types of ESBL enzymes. As a result, their ability to hydrolyze antibiotics has increased, leading to their higher occurrence in clinical samples.

Prevalence and Molecular Characterization of Extended Spectrum β-Lactamase and Carbapenemase-Producing Enterobacteriaceae Isolates from Bloodstream Infection Suspected Patients in Addis Ababa, Ethiopia.

BackgroundProduction of Extended spectrum beta-lactamase (ESBL) and Carbapenemase is the most common strategy for drug resistance in clinical isolates of Enterobacteriaceae. This study was conducted to determine the magnitude of ESBL and Carbapenemase production (CPE) among clinical isolates of Enterobacteriaceae causing bloodstream infections (BSI) in Ethiopia.MethodsA cross-sectional study was performed from September 2018 to January 2019 in Ethiopia. A total of 2397 BSI suspected patients were enrolled and blood culture was performed using a BacT/Alert instrument in combination with conventional methods for identification. After antimicrobial susceptibility test, phenotypic confirmation of ESBLs was done by combined disc-diffusion. Meanwhile carbapenemase production was done by modified carbapenem inactivation method. Multiplex PCR was conducted to detect the presence of blaCTX-M,blaSHV, blaTEM, blaKPC and blaNDM genes.ResultsA total of 104 (4.3%) Enterobacteriaceae were isolated from 2397 BSI suspected patients. Klebsiella pneumoniae (55/104, 52%) was the predominant isolate followed by E. coli, (19.2%, 20/104) and K.oxytoca (17.3%, 18/104). ESBL and carbapenemase production were observed from 70 (67.3%, 57.4 −76.2% at 95% CI) and 8 (7.7%, 3.4–14.6% at 95% CI) isolates respectively. The highest frequency of ESBL and carbapenemase production was observed in K. pneumoniae 78.2% (43/55) and 9.1% (5/55), respectively. All the 70 isolates confirmed as ESBL producers harbored at least one of the ESBL genes and the majority of them carried multiple beta-lactamase genes (84.3%), where blaCTX-M, type was the most predominant (67.3%). Similarly, the entire eight isolates positive for carbapenemase carried blaNDM but none of them carried blaKPC.ConclusionIn our study, the rate of ESBL production among BSI-causing Enterobacteriaceae was alarming and most of the isolates carried multiple types of ESBL genes. A significant magnitude of CPE isolates causing BSI was recorded.

598. A 3-Year Evaluation of Antibiotic Resistance Patterns in Gram-Negative Genitourinary Tract Infections Treated in Outpatient Infusion Centers (POICs)

BackgroundResistant Gram-negative pathogens (GNP) are common causes of genitourinary tract infections (GUI) often requiring outpatient parenteral antibiotic therapy (OPAT). Data are sparse regarding antibiotic resistance of GNP in patients (pts) treated with OPAT. We analyzed GNP of GUI pts treated in Infectious Disease OICs over a 3-year period stratified by location prior to OPAT.MethodsRecords from 18 POICs were queried for GUI pts with ≥1 GNP receiving OPAT from 2018 to 2020. Demographics, pt location prior to OPAT, infection type, year of therapy, and GNP were recorded. Antibiotic resistance patterns were defined as extended-spectrum beta-lactamase (ESBL) or multi-drug resistant (MDR). Chi Square and Fisher’s exact test were used to determine if ESBL status was associated with GNP or location prior to OPAT (hospital vs. community). The Cochran-Armitage test was used to analyze temporal trend in ESBL expression. Statistical significance was defined as P< 0.05 for all tests. ResultsA total of 634 GNP were identified in 601 pts (mean age: 64±16, 58% female). Infections were 75% complicated urinary tract infection, 20% pyelonephritis, and 5% prostatitis/other. Overall, 56% (n=339) were treated directly from the community and 44% (n=262) following hospital discharge. GNP isolated were 56% E. coli, 19% Pseudomonas spp., 16% Klebsiella spp. and 9% others. Of the 611 GNP with potential to express ESBL, 43% (n=265) were ESBL producers (Table 1). Significantly more ESBL-producing GNP occurred in pts discharged from a hospital prior to OPAT compared to the community (53% vs. 36%, P< 0.001). Overall, the incidence of MDR constituted 36% (n=231) of GNP, which did not differ by location prior to OPAT. Evaluation of ESBL incidence by year showed a significant increase from 2018 to 2020 (P=0.03). Although a slight increase in MDR was noted from 2018 to 2020, this was not significant (Figure 1).Table 1. Frequency of ESBL and MDR by Location prior to OPAT Figure 2. Prevalence of ESBL producers and MDR Pathogens by Year ConclusionResistant GNP were observed in the OPAT setting for GUI with both ESBL and MDR pathogens. We saw a significantly higher rate of ESBL with GNP from hospital discharged pts compared to community-acquired infections and an increase in the overall incidence of ESBL over time. Management of Gram-negative genitourinary infections in the OPAT setting requires close monitoring of emerging resistance patterns. Disclosures Kimberly A. Couch, PharmD, MA, FIDSA, FASHP, AbbVie (Speaker's Bureau) Lucinda J. Van Anglen, PharmD, Merck & Co. (Research Grant or Support)

Detection of Extended Spectrum Beta Lactamases (ESBLs) Producing Enterobacteriaceae Family from Urinary Tract Infection (UTI) Patients

Background: Extended spectrum beta lactamase (ESBLs) are betalactamase capable of conferring bacterial resistance to the first, second and third-generation Cephalosporin’s but these are inhibited by lactamase inhibitors such as clavulanic acid. The ESBLs are typically plasmidmediated enzymes, mostly produced by E. coli and Klebsiella pneumonia Enterobacteriaceae family. ESBLs enzymes were discovered in Germany in 1983 from Klebsiella pneumonia. ESBL-producing gram negative bacteria have been responsible for numerous outbreaks of infection throughout the several counties and region challenging infection control issues. Different phenotypic test for ESBL detection have been developed, which are easy to use and cost effective. Materials and Methods: In this study, 10 Urine samples were collected from Government Hospital, Dharmapuri, Tamil Nadu. Collected clinical samples were isolated and identified by standard microbiological method. The antibiotic susceptibility testing was performed by the disc-diffusion method. The preliminary phenotypic detection of ESBLs was carried out by combination disc-diffusion test (CDDT) Performed using Kirby- bauer disc diffusion method on muller hinton agar. Results: Totally 10 clinical samples were collected and investigated Among 7 clinical samples of positive of Urinary tract infection (UTI), 20 micro-organisms belonging to 3 genus were isolated. Of the patients, 7 were female and 3 were male. E. coli and Klebsiella pneumonia were most prevalent species. E. coli and Klebsiella pneumonia were multidrug-resistant (resistance to five or more antibiotics) among the isolates. Of the isolated in Uro pathogens such as E. coli and Klebsiella pneumonia were ESBLs positive. Conclusion: Based on the results, E. coli and Klebsiella pneumonia predominated in the samples, giving the maximum frequency of ESBLs producing followed by E. coli (70%) and Klebsiella pneumonia (30%) from the combined disk diffusion method. Herbal medicine should be perform for UTI patients to prevent the spread of more. Only limited therapeutically options for ESBL-PE.

Incidence of Beta-Lactamase Enzymes among Klebsiella pneumonia Isolates Causing Urinary Tract Infections in Aliabad, North-East Iran

AimsIn the past decade, drug resistance in Gram negative bacilli has become a serious problem. The production of extended spectrum beta-lactamase (ESBL), AmpC beta-lactamase, and metallo beta-lactamase (MBL) enzymes in Klebsiella pneumoniae strains is the mechanism of drug resistance among these commonly isolated Gram negative bacteria from clinical specimens. The aim of this study was to assess the frequency of β-lactamase enzymes, including extended spectrum β-lactamases (ESBLs), metallo-β-lactamases (MBLs), and AmpC beta-lactamases, in K. pneumonia strains isolated from urine samples referred to medical laboratories in Aliabad.Materials & MethodsA total of 780 urine samples were collected from patients suspected of having UTI from March to June 2017. In positive urine samples, K. pneumonia isolates were identified by biochemical tests. Antibiotic resistance pattern was determined by disk diffusion method, and phenotypic confirmatory test was performed for detecting ESBLs, MBLs, and AmpC BLs producers.FindingsOut of 378 positive samples for UTI, 97 K. pneumonia strains were isolated. Most of the isolates (more than 90%) were resistant to ampicillin and amoxicillin; however, imipenem and amikacin were effective antibiotics against the isolates. The frequency of ESBLs, MBLs, and AmpC BLs producers was determined as 33.3, 21.3, and 5.1%, respectively.ConclusionsIn this study, 14 isolates were simultaneously positive for ESBL and AmpC BL production, and 2 isolates were co-producer of ESBL and MBL. This finding could have a great impact on the management and treatment of UTI cases. Therefore, detection of beta‑lactamases is of great importance for controlling and reducing the spread of ESBL, AmpC BL, and MBL producing strains.

Frequency and Susceptibility Pattern of Extended Spectrum Beta Lactamase Producing Aerobic Gram Negative Bacteria in Post-Operative Infections

Extended spectrum β-lactamases occur commonly in the aerobic Gram negative bacteria (AGNB) such as <i>E. coli</i>, <i>Klebsiella</i> spp., <i>Proteus</i> spp., <i>Pseudomonas aeruginosa</i>, <i>Acinetobacter</i> spp., etc. and have the ability to make these organisms resistant to cephalosporins (e.g. ceftazidime, ceftriaxone, cefotaxime etc.), penicillins, and monobactams, i.e. aztreonam. However theses antibiotics become sensitive in the presence of clavulanic acid, an extended spectrum beta-lactamase (ESBL) inhibitor. ESBL enzymes do not influence cephamycins or carbapenems, i.e. meropenem, imipenem, etc. Major problems in surgery is wound infections after operations. High risks of wound infections are due to being immune-comprised on antibiotics, prolonged hospitalization and other factors in many cases. The current research determined various aerobic gram negative bacteria in post-operative wound infections at the College of Medical Laboratory Technology, the National Institute of Health, Islamabad, Pakistan. It also determined the frequency of ESBL in the organisms and established their susceptibility profile during the time period of the research. Infections caused by ESBL producers are a major problem in our post-operative patients. The commonest isolate was <i>E. coli</i> and the commonest ESBL producer was <i>Klebsiella</i> spp. Double disk synergy test is an effective method for screening of such isolates, and the practice of incorporating this test along with the routine sensitivity is recommended.

Frequent isolation of extended-spectrum beta-lactamase-producing bacteria from fecal samples of individuals with severe motor and intellectual disabilities.

Extended-spectrum beta-lactamase (ESBL) producing bacteria spread worldwide and became major concern for antibiotic treatment. Although surveillance reports in general hospitals and long-term care facilities are increasing, their frequencies in individuals with severe motor and intellectual disabilities (SMID) are so far unknown. In this study, we examined the frequency of ESBL in stool samples collected from 146 asymptomatic SMID subjects hospitalized in a single institution. With their clinical information, we evaluated possible risk factors for ESBL colonization. From 146 fecal samples, ESBL-producing bacteria were isolated in 45 cases (31%). Drug sensitivity testing showed that 82% of the isolates were resistant to levofloxacin but were sensitive to tazobactam/piperacillin and cefmetazole. The most frequent genotype was CTX-M-9 detected in 36/45 (80%). A high degree of disability, antibiotic use within three months before sampling and post-tracheostomy were statistically significant risk factors. Tube feeding was also strongly correlated with ESBL colonization (p<0.001) and associated with lower micro-organismic diversities. Our findings are the first to reveal a high prevalence of ESBL in the fecal samples of SMID individuals and suggest possible relationships between high degree disability, tube feeding and latest histories of antibiotic use.

Antimicrobial susceptibility of extended-spectrum beta-lactamase producing &lt;i&gt;Enterobacteriaceae&lt;/i&gt; causing urinary tract infections in Ouagadougou, Burkina Faso

Objective: To determine the frequency of extended-spectrum beta lactamase producing Enterobacteriaceae (ESBL) and other antibioticsresistant bacteria in urinary tract isolates.Study Design: prospective and experimental study.Methodology: Place and duration of study :YalgadoOuedraogo University Hospital Center, Charles De Gaulle Pediatric Hospital Center, Saint Camille Hospital and National Public Health Laboratory, Ouagadougou, from November 2014 to October 2015.AllEnterobacteriaceaestrains isolated from urinary samples of patients were identifiedusing API 20E chemical gallery (BioMerieux, France). All strains were subjected to an array of 14 antibiotics to study their drug susceptibility by using Kirby- Baeurdisk diffusion method. Detection of ESBL was carried out by double disk diffusion technique. Statistical analysis was performed by Microsoft Excel and Anova one-way GrapPad Prism version 5.01. Chi-square (χ2) test was used to determine significance. A p˂ 0.05was considered to be statistically significant.Results: A total of 324 isolates of Enterobacteriaceae were identified during the study period, including211(65%) E. coli, 75 (23%)Klebsiella spp., 18 (6%) Enterobacter spp., 11 (3%)Proteus spp., 5 (2%) Citrobacter spp., Serratia spp. 3 (1%).All the clinical isolates were susceptible to imipenem. Resistance to amikacinwas 14% (45/324); gentamicin 54% (175/324); tobramycin 58% (187/324); nalidixic acid 72% (234/324),ciprofloxacin 63% (204/324) and to cotrimoxazole 83% (269/324).The overall rate of the EBSL producing strains was 35% (114/324). Their susceptibility to antibiotics was (imipenem,amikacin, cefoxitin and fosfomycin) 100% (114/114), 93% (106/114), 74% (84/114) and 84% (96/114) respectively. ESBL positivity within individual organism group was highest inEscherichia coli 64% (73/324) followed byKlebsiellaspp. 28% (32/324), Enterobacterspp. 3% (4/324), Proteus spp. and Citrobacterspp. 2% (2/324).Conclusion: The results showeda high frequency of ESBL producing Enterobacteriaceae, especially Escherichia coli and Klebsiellaspp. The data points to theneed of routine detection and surveillance of ESBL producing bacteria in Burkina Faso.Keywords: Antimicrobial susceptibility, Enterobacteriaceae, Urine, Burkina Faso

Frequency of Extended-Spectrum Beta-Lactamase (ESBLs) –Multidrug Resistance Produced by Pseudomonas aeruginosa Isolated from Clinical Specimens in Khorramabad City, Iran

Background: Pseudomonas aeruginosa is one of the most important pathogenic bacteria causing hospital infections, which has intrinsic resistance to many antibiotics. One of the reasons for the emergence of drug resistance in P. aeruginosa isolates is the production of ESBLs (extendedspectrum beta-lactamase) enzymes. Resistance rate is increasing due to the production of these enzymes in P. aeruginosa. The goal of this study was to determine the prevalence of ESBL senzymes in P. aeruginosa isolates from different samples of patients in Khorramabad city by CDT (combined disk test) phenotypic method. Methods: This study was an investigation on 70 P. aeruginosa samples isolated from patients in Original Research Article Azizi et al.; BMRJ, 5(6): 490-495, 2015; Article no.BMRJ.2015.052 491 medical centers of Khorramabad city during one year (2013). The bacteria were identified by routine biochemical tests. Antibiotic sensitivity of the isolates was evaluated by double disk diffusion method. Phenotypic investigation of ESBLs production among the tested isolates using cefotaxime and ceftazidime disks alone and in combination with clavulanic acid (combined disk test) was performed. Results: Results of combined disk test showed that, out of 70 isolated pseudomonas, 100% of the samples had multi-drug resistance. Maximum resistance to cefixime (79.1%) and minimum resistance to meropenem (25%) were observed. Out of 70 isolates, 25 (35.7%) were phenotypic beta-lactamase-producing enzymes. That highest percentage was related to wounds, equal to 12 (17%). Conclusion: Considering the increasing prevalence of P. aeruginosa strains which produce extended-spectrum beta-lactamase, it is recommended to use an appropriate treatment protocol based on determining antibiogram pattern of strains. This means that all isolated before treating with antibiotics were examined by antibiotic susceptibility test. Also antibiotics should be used according to CLSI (Clinical and Laboratory Standards Institute). This issue is of serious concern for applying infection-control criteria with the purpose of preventing spread of this microbe.

Occurrence and antimicrobial susceptibility pattern of ESBL-producers among Gram-negative bacteria isolated from burn unit at the Al Shifa hospital in Gaza, Palestine : A short original article

AbstractBackground: Infection is an important cause of death in burns. The emergence of antimicrobial resistant pathogens like ESBL producers is leading to inappropriate/or treatment failure and increased morbidity and mortality.Objective: the purpose of this study was to determine the antimicrobial susceptibility pattern with the identification of Extended spectrum Beta-lactamase (ESBL) producers among pathogens isolated from burn patients at Al-Shifa burn unit in Gaza, Palestine.Methods: A total of 40 gram-negative bacterial isolates were obtained from burn wound patients at Al-Shifa Hospital burn unit from August 2012 to December 2012. Antibiotic susceptibility profiles were determined by the standard disc diffusion method according to CLSI guidelines. The ESBL detection was screened by using double disc diffusion method.Results: Pseudomonas aeruginosa was the predominant isolate 15 (37.5%) followed by Klebsiella pneumoniae 10 (25%), Escherichia coli 9 (22.5%), Enterobacter cloacae 4 (10%) and Acinetobacter baumannii 2 (5%). ESBL was detected in 37.5% of isolates. Most of ESBL-producing isolates were susceptible to meropenem and imipenem (80% and 73% respectively). However, ESBL producing isolates showed 100% resistance against cefotaxime, followed by ampicillin with 93.3% resistance. The resistance rate towards sulfamethoxazole/trimethoprim, tetracycline, cefepime, tobramycin and aztreonam was 80%, 73.3%, 66.7%, 60% and 60% respectively. A. baumannii isolates were resistance to all tested antibiotics.Conclusion: P. aeruginosa is the most common bacteria isolated from burn wound patients. The frequency of ESBL among gram-negative bacteria is high. Carbapenems including imipenem and meropenem remain the most effective treatment options against gram-negative producing ESBL isolated from Al-Shifa burn unit.

Microbial resistance and frequency of extended-spectrum beta-lactamase (ESBL) in isolated from blood cultures

Introduction: The emergence and spread of isolated carriers of extended-spectrum beta-lactamase (ESBL) have complicated the treatment of nosocomial infections, since its production is not easily identified by the sensitivity tests, routinely performed in clinical laboratories, leading to difficulties in the hospital control of resistant microorganisms and antibiotics misuse. Objective: The objective of this study was to analyze the resistance profile and the frequency of ESBL in Gram-negative bacteria isolated from blood cultures. A hundred bacterial samples from blood cultures of adult patients were analyzed, which were phenotypically identified by biochemical tests of carbohydrates fermentation and submitted to determination of the resistance profile by disc diffusion test and ESBL screening by disc approximation and disc replacement methods. Results: Among the bacterial samples tested, 30 were identified as Gram-negative bacteria, predominantly by Proteus mirabilis, Pantoea agglomerans, and Escherichia coli. Of these, 73.33% were positive for the detection of ESBL by phenotypic tests, and was found mainly in Pantoea agglomerans, Proteus mirabilis, and Enterobacter cloacae. Conclusion: The increase in the occurrence of ESBL in different Enterobacteriaceae shows the importance of the amplification of detection in other species than Escherichia coli or Klebsiella sp., so that the assistance to the patient is not restrained, since these resistant bacteria cannot be detected by the laboratories. Considering the frequency of ESBL in this study, we highlight the importance of its detection, aiming to its contribution to the development of improvements in the health care policies of hospitals.

The resistance rates of urinary tract infections: Our data from year 2010.

More than 95% of all urinary tract infections are caused by a single bacterium. Although E. coli is the most common bacterium causing community-acquired infections, Klebsiella spp., enteric gram-negative bacteria and S. saprophyticus have been also identified. This study evaluated the microorganisms isolated from the urine cultures of patients admitted to our outpatient clinics in 2010 and assessed E. coli resistance and the frequency of extended-spectrum beta lactamase (ESBL)-producing bacteria. In total, 7145 urine cultures were obtained from patients admitted to all clinics between 1 January 2010 and 31 December 2010. The double-disk synergy test was used to identify the presence of ESBL producers. The most frequently isolated microorganisms were E. coli (60.6%), Enterococcus spp. (10.3%), Klebsiella spp. (7.3%), Pseudomonas spp. (4.8%), and Streptococcus spp. (3.3%). E. coli strains were more resistant to ciprofloxacin (45.12%), trimethoprim-sulfamethoxazole (44.8%) and amoxicillin-clavulanate (31.6%), but they were less likely to be resistant to meropenem (0%), imipenem (0.2%), and amikacin (0.7%). The frequency of ESBL-producing E. coli strains was 14%. The choice of antibiotic treatment influences the overall success of treatment and the development of resistance, and it is also closely related to the cost of the treatment. As a result, there is a need to review the current treatment protocols. As resistance rates show regional differences, it is necessary to regularly examine regional resistance rates to determine the appropriate empiric antibiotic treatment and reduce costs.

Isolation of ESBL producing organisms by Double Disc Synergy Test in tertiary care hospital

Extended spectrum beta-lactamase (ESBL) producing organisms pose unique challenges to clinical microbiologists, clinicians, infection control professionals and antibacterial discovery scientists. The study was done to determine ESBL producing strains by a most feasible and accurate phenotypic method. Urine, surgical wound swab, burn wound swab and pus samples were taken from Sir Salimullah Medical College and Mitford Hospital and from Burn Unit of Dhaka Medical College Hospital from January 2011 to December 2011. ESBL producers were detected by Double Disc Synergy Test. From 354 different samples, 59.04% organisms were isolated. Among them 89% were Gram-negative organisms. Out of these Gram-negative organisms 41.40% isolates were ESBL producers. Among them 75% were Klebsiella spp. and 41.67% were Esch coli. This study shows that the frequency of ESBL producing strains of Esch. coli and Klebsiella spp. is high in both hospitals and it has a significant inference for patient's management. Hence, it is very important that a doctor should be familiar with the clinical significance of these enzymes and potential strategies for dealing with this growing problem.DOI: http://dx.doi.org/10.3329/bjmm.v7i2.19330 Bangladesh J Med Microbiol 2013; 07(02): 21-24

English

BACKGROUND: Beta lactams are the most extensively used group of antimicrobials, however growing resistance to these invaluable drugs mediated by extended spectrum beta-lactamase (ESBL) enzymes is a major concern. The frequency of ESBL producing strains among clinical isolates has been steadily increasing over the past few years that has generated a major problem in clinical therapeutics. OBJECTIVES: Our aim was to determine the prevalence of ESBL producing Escherichia coli, study their antibiogram and to evaluate the association between ESBL production and antibiotic resistance in Escherichia coli. SETTINGS AND DESIGN: This prospective study was conducted in the Department of Microbiology, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh. STATISTICAL ANALYSIS USED: Chi-square test was used to analyze the data statistically. Probability values less than 0.05 were considered significant. MATERIALS AND METHODS: Two hundred and eighty six consecutive, non-repeated isolates of Escherichia coli obtained from pus, urine, blood, stool, throat swab, cervical swab, sputum, CSF and conjunctival swab samples received in our bacteriology laboratory were analyzed in this study. These bacterial isolates were identified and tested for antibiotic sensitivity by standard microbiological procedures. Subsequently, they were screened and then phenotypically confirmed for ESBL production by phenotypic confirmatory disk diffusion test (PCDDT). RESULTS : Out of 286 isolates of Escherichia coli screened for ESBL production, 65.03% (n=186) were detected to be positive using either ceftazidime or cefotaxime. In the screen positives, 91.94% (n=171) were phenotypically confirmed ESBL producers by PCDDT method. The overall prevalence of ESBL producing Escherichia coli was 59.79% (n=171/286) with 87.72% obtained from in-patients and 12.28% from out-patients. Majority of ESBL producing Escherichia coli were recovered from stool (73.33%), followed by pus (62.62%), urine (61.80%) and blood (60.61%) samples. The antibiogram revealed no resistance to imipenem, while the highest resistance rate was detected against cefoperazone, amoxicillin/clavulanic acid, ampicillin, cefotaxime, aztreonam, cefoxitin, piperacillin, ceftazidime, and ceftriaxone. CONCLUSIONS: ESBL producing strains of Escherichia coli show extremely wide spectrum of antibiotic resistance including resistance to penicillins, cephalosporins, aminoglycosides, and fluoroquinolones. This leads to significant implications in the management of patients. Advanced drug resistance surveillance and determination of molecular characteristics of ESBL isolates are necessary to formulate antibiotic prescription policies, so as to ensure appropriate and judicious use of the available antimicrobial drugs.

Antibiogram pattern in extended spectrum beta lactamase nano enzyme producing gram negative bacilli in Iranian urinary tract infection

Urinary tract infection is one of the most prevalent infections worldwide. Extended spectrum beta lactamase (ESBL) is defined as beta lactamase capable of hydrolyzing third generation cephalosporin's, and is inhibited by beta lactamase inhibitor. Escherichia coli and Klebsiella pneumoniae are relevant opportunistic pathogens that account for nosocomial infections. Antibiotics resistance in extended spectrum beta lactamase producer strain is currently one of the emerging health related problems in the world. The present study was performed in two tertiary care hospitals in Iran during a 14 month period. Standard microbiological methods were performed. In order to validate the extended-spectrum beta-lactamases producing strains, ceftazidim, ceftazidimclavulanic acid, cefotaxim, and cefotaximclavulanic acid were used, by disk diffusion method. Frequency of ESBLs in E. coli and K. pneumoniae strains was 35.06 and 35.71%, respectively. According to antibiogram result respectively 59.2, 54.9, 30.3, 27.8, 19.5 and 16.7% of E. coli strains were resistant to co-trimoxazole, nalidixic acid, ciprofloxacin, gentamicin, ceftazidime and nitrofurantoin, and respectively 75, 50, 40, 44.5, 37.5, 37.5, 22.3 and 0% of K. pneumoniae strains were resistant to ampicillin, co-trimoxazole, nitrofurantoin, ceftazidime, amikacin, cephotaxime, imipenem and ciprofloxacin. Justifiable use will be an effective means of controlling and decreasing spread of beta lactam antibiotics strains. Key words: Escherichia coli, Klebsiella pneumoniae, urinary tract infection, extended spectrum beta lactamase.

Frequency of extended spectrum beta lactamase producing enterobacteriaceae among urinary pathogen isolates.

To determine the frequency of extended-spectrum beta lactamase (ESBL) producing Enterobacteriaceae in urinary isolates. Observational study. Ziauddin University Hospital, Karachi, from February to October 2008. All members of Enterobacteriaceae isolated from urinary samples of in-patients were included and identified using standard biochemical tests. Urinary samples from out-patients were excluded. Detection of ESBL was carried out by double disk diffusion technique. Statistical analysis was performed by SPSS version 10. A total of 289 isolates of Enterobacteriaceae were identified during the study period. Of those 190/289 (65.7%) of the isolates were found to be ESBL producing. ESBL positivity within individual organism group was highest in Klebsiella species 84.16%, followed by Escherichia coli 68.55%, Enterobacter species 36.84%, and Proteus mirabilis 28.55%. Mean age of patients with ESBL producing organisms was 58.69 ± 18.97 years. ESBL production was almost similar in all age groups. A high frequency of ESBL producing organisms especially Klebsiella species and Escherichia coli amongst the hospital obtained urinary isolates was documented particularly in the older age group. The data points towards an urgent need for regular screening and surveillance for ESBL producing organisms in this region.

Bacteremia due to multidrug-resistant (MDR) and extended-spectrum beta-lactamase (ESBL) producing Acinetobacter baumannii

Bacteremia due to Acinetobacter baumannii is a common problem in hospitals worldwide. Physicians in the intensive care units (ICUs) encountered a serious challenge of finding a drug to cure the extended-spectrum beta-lactamase (ESBL) producing and multi-drug resistant (MDR) A. baumannii bacteremia. Our aim was to determine the frequency of A. baumannii bacteremia in an Iranian hospital ICUs, their antibiotic susceptibility patterns, and the frequency of ESBLs by a cross-sectional study. A total of 340 patients admitted to ICUs during a 6 month period of study were investigated for bacteremia due to A. baumannii. Bacteria isolates from blood specimens were identified as A. baumannii by API 20NE system. Antimicrobial susceptibility was studied with disk diffusion method. Detection of ESBLs was done by double disk synergy test. Of the 340 patients investigated, bacteremia was found in 114 cases (33%). A. baumannii was diagnosed as the etiological agent of bacteremia in 69 cases (60.5%). All the isolates were multi-drug resistant. Except one, all the remaining isolates (98.6%) were resistant to at least 7 of 13 tested antibiotics. Pandrug-resistance was observed in 4 isolates (5.6%). Of all the isolated A. baumannii, 49 (71%) were found to be resistant to cephalosporins by screening tests and among them 27 isolates (39%) were found to be ESBL producing.Our study showed a high frequency of A. baumannii bacteremia occurrence in our hospital ICUs. An urgent intervention is needed to reduce the MDR bacterial load in these critical units. Key words: Acinetobacter baumannii, bacteremia, multi-drug resistant, extended-spectrum beta-lactamase.

Frequency of extended spectrum beta-lactamase (ESBLs) producing Escherichia coli and Klebseilla pneumonia isolated from urine in an Iranian 1000-bed tertiary care hospital.

Betal-lactam antibiotics are the most frequently prescribed antibiotics. Emerging resistance to these antibiotics among gram-negative bacilli limited their utility. This study was done to determine the frequency of extended spectrum beta-lactmase (ESBLs) producing Escherichia coli and Klebsiella pneumoniae isolated from urine in Milad Hospital of Tehran. This study was done on 735 urine gram-negative bacilli isolates including 620 strains of E. coli and 115 strains of K. pneumoniae in microbiology laboratory of Milad Hospital in Tehran, Iran. ESBls resistance was detected in 132 (21%) of isolates of E. coli and 18 (12%) in those with K. pneumoniae. Of 150 patients which had positive ESBLs isolates, 104 were outpatients and 46 others were hospitalized. Nearly 80% ESBls isolates were resistant to co-trimoxazole and nitrofuantion was the most effective antibiotic against ESBLs producing isolates. Our study revealed that there is a high frequency isolates of ESBls producing strains of E. coli and K. pneupmiae in both community and hospital. This has a significant implication for patients’ management. Further drug resistance surveillance in our hospitals and molecular characteristics of ESBls isolates in our country is necessary. Key words: Extended spectrum beta-lactamase (ESBLs), Escherichia coli,Klebseilla pneumonia, urinary tract.

Antibiogram of Extended Spectrum Beta-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae isolated from Hospital Samples

Extended spectrum beta-lactmase (ESBL) producing organisms create a major problem for clinical therapeutics. The frequency of ESBL producing strains among clinical isolates has been steadily increasing over the past few years resulting in limitation of the therapeutic options. These resistant bacteria are emerging world wide as a threat to human health in both the community and hospital settings. -lactamase production by several organisms is the most important mechanism of resistance to beta-lactam antibiotics, such as penicillins and cephalosporins. This study was done to determine the susceptibility of different antimicrobials to ESBL producing Escherichia coli and Klebsiella pneumoniae isolated from wound swabs, blood, urine, fluid, tracheal aspirates and sputum in Shahid Bahonar Hospital of Tehran from July, 2007 to June, 2008. A total of 115 ESBLproducing isolates were obtained from outdoor and indoor patients. Out of 115 isolates, 60% were E. coli and 40% were K. pneumoniae. All ESBL-producing isolates were confirmed using the Clinical and Laboratory Standards Institute (CLSI)-approved double-disk diffusion method. 29.6% of these isolates were collected from medical wards and 24.3% were collected from outdoor. Urine (70.4%) was the main source of ESBL-producing isolates from all patients, followed by blood (16.5%). All isolates were susceptible to both imipenem and meropenem. Of all isolates, 93.9% were susceptible to amikacin. The cephalosporins (1-4 generations) were almost 100% resistant. For Nitrofurantoin, 57.4% were sensitive. High rate resistance (74.8%) was observed to all quinolones tested. Aztreonam, Ampicillin, Co-amoxyclav and Ampicillin/Sulbactam were 100% resistant. This study shows that the frequency of ESBL producing strains of E. coli and K. pneumoniae is high in both hospital and community levels and it has a significant implication for patients’ management. Advance drug resistance surveillance and molecular characteristics of ESBL isolates is necessary to guide the appropriate and judicious antibiotic use. Key words: Extended spectrum beta-lactamase (ESBL), Drug sensitivity, Escherichia coli, Klebseilla pneumoniae DOI: http://dx.doi.org/10.3329/bjmm.v4i1.8467 BJMM 2011; 4(1): 32-36