scholarly journals Susceptibility Pattern and Distribution of Oxacillinases andblaPER-1Genes among Multidrug ResistantAcinetobacter baumanniiin a Teaching Hospital in Iran

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Sareh Bagheri Josheghani ◽  
Rezvan Moniri ◽  
Farzaneh Firoozeh ◽  
Mojtaba Sehat ◽  
Yasaman Dasteh Goli

Acinetobacter baumannii (A. baumannii)is an important nosocomial pathogen in healthcare institutions.β-Lactamase-mediated resistance is the most common mechanism for carbapenem resistance inA. baumannii. The aim of this study was to determine the antibiotic resistance pattern, to detectOXAencoding genes, class A,blaPER-1, and to detect the presence of ISAba1. A total of 124A. baumanniiisolates were collected from hospitalized patients in a teaching hospital in Kashan, Iran. The susceptibility of isolates to different antibiotics was determined by disk-diffusion method. PCR was used to detectblaPER-1,blaOXA-23,blaOXA-24,blaOXA-51,blaOXA-58, and ISAba1 genes. All isolates were resistant to ceftazidime, ceftriaxone, and cefotaxime. All of the isolates revealed susceptibility to polymyxin B and colistin. Ninety-six percent of the isolates were extensive drug resistance (XDR), 5.6% extended spectrum beta-lactamase (ESBL), and 54.8% metallo-beta-lactamase (MBL). All isolates were positive forblaOXA-51and ISAba1.blaOXA-23,  blaOXA-24, andblaOXA-58were found in 79.8%, 25%, and 3.2%, respectively. The frequency rate ofblaPER-1gene was 52.4%. Multidrug resistantA. baumanniiisolates are increasing in our setting and extensively limit therapeutic options. The high rate presence of class D carbapenemase-encoding genes, mainlyblaOXA-23carbapenemases, is worrying and alarming as an emerging threat in our hospital.

Author(s):  
Ranjit Sah ◽  
Shusila Khadka ◽  
Gentle Sunder Shrestha ◽  
Subhash Acharya ◽  
Diptesh Aryal ◽  
...  

Abstracts Background Resistance to antimicrobial agents of pathogenic bacteria has become a major problem in routine medical practices. Carbapenem resistance has long been increasing. The production of carbapenem- hydrolysing β-lactamases (carbapenamases), which include NDM, KPC, OXA-48, IMP-1 and VIM is the most common mechanism. Case presentation A 56 years old male presented with fever and mental changes with progressively decreasing sensorium for the last 3 days. He was admitted to Intensive care unit (ICU) with a diagnosis of meningoencephalitis. On day seven, he developed ventilator associated pneumonia due Klebsiella pnemoniae and Acinetobacter baumannii. He was on meropenem, but the isolates were susceptible to colistin, tigecyclin and amikacin solely. Hence, amikacin was started with addition of intravenous and nebulized colistin. Subsequently, vital signs improved with resolution of fever. However, on day 18, he developed fever once again with a drop in blood pressure. Inotropic support was maintained, and echinocandins and tigecycline were added to the regimen. Repeat blood and urine culture grew Providencia species, which were resistant to most of the drugs on phenotypic Kirby-Bauer disk diffusion method and are intrinsically resistant to colistin and tigecycline. Phenotypic detection of ESBL (combined disk method), MBL, KPCs, AmpC and co-producer were tested according to updated CLSI guideline and all were negative. But the Modified Hodges test was found to be positive. Consequenty, OXA-48 drug resistance pattern was brought into action by blank disc method according to A Tsakris et al., which revealed indentation of growth toward both EDTA and EDTA/PBA disk indicating production of OXA-48 carbapenamase. To confirm the resistance pattern we processed the isolated colonies for Xpert Carba-R (Cepheid) assay, which detected blaOXA-48 gene and confirmed the OXA-48 drug resistance pattern. Hence, the infecting organism was not susceptible to any of the antibiotics. The patient was kept under isolation and on 31th day of admission, he died of septic shock. Conclusions Carbapenamase production along with intrinsic colistin resistance in infecting bacterial pathogens can cause fatal outcomes in the resource limited countries like Nepal where new antibiotic combinations ceftazidime+ Avibactam, or aztreonam +avibactam are not available. Drug resistance patterns including OXA 48 producer should be characterized in all cases by standard phenotypic methods or by Xpert Carba-R assay and larger studies are required to know the exact burden of OXA 48 producer in Nepal.


2011 ◽  
Vol 2 (1) ◽  
pp. 8
Author(s):  
Ronak Bakhtiari ◽  
Jalil Fallah Mehrabadi ◽  
Hedroosha Molla Agamirzaei ◽  
Ailar Sabbaghi ◽  
Mohammad Mehdi Soltan Dallal

Resistance to b-lactam antibiotics by gramnegative bacteria, especially <em>Escherichia coli (E. coli)</em>, is a major public health issue worldwide. The predominant resistance mechanism in gram negative bacteria particularly <em>E. coli </em>is via the production of extended spectrum beta lactamase (ESBLs) enzymes. In recent years, the prevalence of b-lactamase producing organisms is increased and identification of these isolates by using disk diffusion method and no-one else is not satisfactory. So, this investigation focused on evaluating the prevalence of ESBL enzymes by disk diffusion method and confirmatory test (Combined Disk). Five hundred clinical samples were collected and 200 <em>E. coli </em>isolates were detected by standard biochemical tests. To performing initial screening of ESBLs was used from Disk diffusion method on <em>E. coli </em>isolates. A confirmation test (Combined Disk method) was performed on isolates of resistant to cephalosporin's indicators. Up to 70% isolates exhibited the Multi Drug Resistance phenotype. In Disk diffusion method, 128(64%) <em>E. coli </em>isolates which resistant to ceftazidime and cefotaxime while in Combined Disk, among 128 screened isolates, 115 (89.8%) isolates were detected as ESBLs producers. This survey indicate beta lactamase enzymes are playing a significant role in antibiotic resistance and correct detection of them in phenotypic test by using disk diffusion and combined Disk is essential for accurate recognition of ESBLs.


2010 ◽  
Vol 4 (04) ◽  
pp. 239-242 ◽  
Author(s):  
Supriya Upadhyay ◽  
Malay Ranjan Sen ◽  
Amitabha Bhattacharjee

Introduction: Infections caused by Pseudomonas aeruginosa are difficult to treat as the majority of isolates exhibit varying degrees of beta-lactamase mediated resistance to most of the beta-lactam antibiotics. It is also not unusual to find a single isolate that expresses multiple β-lactamase enzymes, further complicating the treatment options. Thus the present study was designed to investigate the coexistence of different beta-lactamase enzymes in clinical isolates of P. aeruginosa. Methodology: A total of 202 clinical isolates of P. aeruginosa were tested for the presence of AmpC beta-lactamase, extended spectrum beta-lactamase (ESBL) and metallo beta-lactamase (MBL) enzyme. Detection of AmpC beta-lactamase was performed by disk antagonism test and a modified three-dimensional method, whereas detection of ESBL was done by the combined disk diffusion method per Clinical and Laboratory Standards Institute (CLSI) guidelines and MBL were detected by the Imipenem EDTA disk potentiation test. Results: A total of 120 (59.4%) isolates were confirmed to be positive for AmpC beta-lactamase. Among them, 14 strains (7%) were inducible AmpC producers. Co-production of AmpC along with extended spectrum beta-lactamase and metallo beta-lactamase was reported in 3.3% and 46.6% isolates respectively. Conclusion: The study emphasizes the high prevalence of multidrug resistant P. aeruginosa producing beta-lactamase enzymes of diverse mechanisms. Thus proper antibiotic policy and measures to restrict the indiscriminative use of cephalosporins and carbapenems should be taken to minimize the emergence of this multiple beta-lactamase producing pathogens.


2015 ◽  
Vol 8 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Olga I Chub ◽  
Aleksandr V Bilchenko ◽  
Igor Khalin

Background : Increased multidrug resistance of extended-spectrum beta-lactamases (ESBLs) compromises the efficacy of treatment of urinary tract infections. Objective : The objective of this study is to determine the prevalence of ESBL-producing uropathogens from hospitalized patients with chronic pyelonephritis and to identify the presence of genes involved in the resistance. Methods : A cross-sectional study of 105 patients with chronic pyelonephritis, treated in Kharkiv City Clinical Emergency Hospital, Ukraine was carried. Bacterial isolates were collected, antimicrobial susceptibility of isolates was determined by the Kirby Bauer disk diffusion method and screening for the presence of blaSHV, blaTEM, blaCTX-M ESBL genes was performed by polymerase chain reaction. Results : 84 (80%) patients had positive urine cultures. Eschеrichia coli wаs the most common microorganism isolated. Among them, 29 (25.2%) were found to be ESBL producers. Out of 53 E. coli isolates, 10 (18.9%), 4 (7.5%) and 6 (11.3%) were identified to carry bla(TEM), bla(SHV) and bla(CTX-M) beta-lactamase genes, respectively. The highest resistance was observed against ampicillin (75.9%), ciprofloxacin (48.3%), levofloxacin (41.4%) and gentamicin (41.4%). Beside this, only meropenem (96.6% susceptibility), nitroxolinum (86.2%) and fosfomycin (72.4%) exhibited a good enough activity against ESBLs-producing urinary strains. Conclusion : Isоlation and detеction of ESBL-prоducing strаins are еssential fоr the sеlection оf the mоst effеctive antibiоtic for the empiric trеatment.


Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1403
Author(s):  
Josman Dantas Palmeira ◽  
Marisa Haenni ◽  
Jean-Yves Madec ◽  
Helena Maria Neto Ferreira

Resistances to extended-spectrum cephalosporins (ESC) and colistin are One Health issues since genes encoding these resistances can be transmitted between all sectors of the One Health concept, i.e., human, animal, and the environment. Among food-producing animals, sheep farming has long been overlooked. To fill in this knowledge gap, we looked for ESC- and colistin resistance in 21 faecal samples collected from sheep in one farm in the south of Portugal. ESC-resistant isolates were selected on MacConkey agar plates supplemented with cefotaxime. Susceptibility testing was performed by the disk-diffusion method according to CLSI, while colistin MIC was determined by broth microdilution. ESC- and colistin-resistance genes were identified by PCR, and the clonality of all isolates was assessed by XbaI-PFGE. The replicon content was determined by PCR according to the PCR-based replicon typing (PBRT) scheme. Sixty-two non-duplicate ESC-resistant E. coli isolates were identified, which all presented an extended-spectrum beta-lactamase (ESBL) phenotype, mostly due to the presence of CTX-M genes. One CTX-M-1-producing E. coli was concomitantly colistin-resistant and presented the plasmid-mediated mcr-1 gene. Nearly all isolates showed associated resistances to non-beta-lactam antibiotics, which could act as co-selectors, even in the absence of beta-lactam use. The results showed a high proportion of ESBL-producing E. coli in sheep faeces. Their dissemination was very dynamic, with the spread of successful clones between animals, but also a large diversity of clones and plasmids, sometimes residing in the same animal. This study highlights the need for global surveillance in all food-producing sectors, in order to avoid the dissemination of genes conferring resistance to last-resort antibiotics in human medicine.


2019 ◽  
Vol 13 (01) ◽  
pp. 50-55
Author(s):  
Umut Safiye Say Coskun ◽  
Emel Caliskan ◽  
Asegul Copur Cicek ◽  
Halbay Turumtay ◽  
Cemal Sandalli

Introduction: The spread of Acinetobacter baumannii, resistant to most of the available antimicrobial agents, is a serious health problem. The high rate of carbapenem resistance among Acinetobacter baumannii isolates is considered as a threat to public health. In this study, we aimed to determine the antibiotic resistance and related genes in carbapenem-resistant Acinetobacter baumannii isolates. Methodology: Ninety six isolates of A. baumannii were included. Antimicrobial susceptibility was performed by Phoenix Automated System and disk diffusion method. Carbapenem resistane was characterized by scrneeing of resistance genes such as blaTEM, blaSHV, blaCTX-M1-2, blaPER, blaVEB, blaKPC, blaGES, blaNDM, blaVIM, blaIMP and blaOXA23-24-51-58 using multiplex polymerase chain reaction. Results: Resistance for the levofloxacin, gentamicin, amikacin, and tigecycline were determined as 96.9%, 93.7%, 72.9% and 45.8% respectively. Colistin was the only susceptible antibiotic against all clinical isolates. All isolates were defined as multidrug resistance and of these, 31.2% were extensively drug-resistant (sensitive only to colistin). BlaOXA-51­  and blaOXA-23 genes were detected in 100% strains while blaTEM was found in only 2% strains. There was no amplification for the blaSHV, blaCTX-M1-2, blaPER, blaVEB, blaKPC, blaGES blaNDM, blaVIM, blaIMP and blaOXA24-58 genes. Conclusions: The high frequency of blaOXA-23 and low frequency of blaTEM gene was observed that indicate prevalence of a variety of A. baumannii strains. The rates of resistance genes vary from region to region. Studies are required for the prevention and control of A. baumannii infection and to formulate the strategies of antibiotic usage.


Author(s):  
R. C. Osaro-Matthew ◽  
O. G. Nweke

Aim: This study’s aim was to determine the antibiotics resistant profile of lactic acid bacteria isolated from poultry and swine faeces. Study design: Faecal samples from swine and birds were randomly collected from livestock and poultry farms located in Umuahia metropolis, Abia State. Place and duration of study: Department of microbiology, Michael Okpara University of Agriculture Umudike, between January 2019 to August 2019. Methodology: A total of 12 faecal samples, 6 each from swines and birds were examined for the presence of lactic acid bacteria using  Deman Rogosa Sharpe agar supplemented with 0.3% CaCO3 (w/v). Isolates were identified based on their physiological and biochemical characteristics. Antibiotic susceptibility was carried out using disk diffusion method. Results: Of the 12 faecal samples examined, all were positive for lactic acid bacteria, with counts ranging from 1.74 – 2.36 x 106 in swine and 1.52 – 2.08 x 106 in birds. Total of 14 strains that belong to three genera; Lactobacillus, Lactococcus and Streptococcus were isolated, genus Lactobacillus occurred highest 8(57.1%). The isolates showed multidrug resistance and exhibited high rate of resistance to Augmentin (100%), Ceftazidime (100%), Cefotaxime (92.9%), Erythromycin (85.7%), Ceftriaxone (71.4%) and Azithromycin (71.4%). Conclusion: The antibiotic resistance pattern of the isolated lactic acid bacteria is a clear indication that most animal farmers are misusing antibiotics. Therefore, animal farmers should be advised on antibiotic application safety measures.


Author(s):  
Mst. Sonia Parvin ◽  
Sudipta Talukder ◽  
Md. Yamin Ali ◽  
Emdadul Haque Chowdhury ◽  
Md. Tanvir Rahman ◽  
...  

Multidrug resistant extended-spectrum &beta;-lactamase (ESBL)-producing Escherichia coli is considered a serious concern to public health worldwide including Bangladesh, and chicken meat is recognized as an important reservoir of ESBL-Ec dissemination to humans. Therefore, this study aimed to determine the prevalence, and phenotypic and genotypic antimicrobial resistance pattern of ESBL-producing Escherichia coli (ESBL-Ec) in frozen chicken meat. A total of 113 frozen chicken meat samples were purchased from 40 outlets of 9 branded supershops in five megacities in Bangladesh. Isolation and identification of Escherichia coli were done based on cultural, biochemical properties and PCR assay. The resistance pattern was determined by disk diffusion method. ESBL-encoding genes were determined by multiplex PCR. The results showed that 76.1% samples were positive for Escherichia coli, of which 86% were ESBL producers. All the isolates were multidrug-resistant (MDR). Resistance to 9&ndash;11 and 12&ndash;13 antimicrobial classes was observed in 38.4% and 17.4% isolates, respectively while only 11.6% were resistant to 3&ndash;5 classes. The possible extensively drug resistance (pXDR) was found in 2.3% isolates. The high single resistance was observed for oxytetracycline (93%) and amoxicillin (91.9%), followed by ampicillin (89.5%), trimethoprim-sulphamethoxazole and pefloxacin (88.4%), and tetracycline (84.9%). Most importantly, 89.6% of isolates were resistant to carbapenems. All the isolates were positive for blaTEM gene. However, the blaSHV and blaCTX-M-2 genes were identified in two ESBL-non producer isolates. None of the isolates were carried blaCTX-M-1 gene. This study provided evidence of wide dissemination of MDR and existence of pXDR ESBL-Ec in frozen chicken meat in Bangladesh. Our data clearly indicated that frozen chicken meat is, at the present time, the most significant known food source of ESBL-Ec to which peoples are regularly exposed.


2021 ◽  
Vol 8 (4) ◽  
pp. 247-253
Author(s):  
Ali Ozturk ◽  
Hadice Ozcinar ◽  
Bashar Mohammed Salih Ibrahim ◽  
Mehmet Bayraktar

Objective: This study aimed to determine the antibiotic resistance, inducible beta-lactamase (IBL), and Metallo beta-lactamase (MBL) rates in P. aeruginosa isolates. Material and Methods: In our study, 100 P. aeruginosa isolates obtained from various clinical samples were used. Antibiotic susceptibility was performed by using the Kirby-Bauer disk diffusion method. Carbapenem resistance to imipenem and meropenem was verified by the E test. The disk induction method was used to determine the IBL production while the Modified Hodge test, MBL E test, and combined imipenem/ EDTA disk were used to determine the production of MBL. Results: According to the results of antibiotic susceptibility tests, 58% of P. aeruginosa isolates were susceptible to all antipseudomonal drugs, while resistance rates to other drugs were as follows; ceftazidime 7%, cefoperazone sulbactam 8%, cefepime 13%, piperacillin 14%, piperacillin-tazobactam 12%, imipenem 9%, meropenem 11%, aztreonam 8%, amikacin 8%, gentamicin 13%, tobramycin 12%, netilmicin 19%, There was a 10% resistance to ciprofloxacin. 8% of the isolates were resistant to at least three drugs, of which two isolates were positive for MBL enzyme production. IBL production was detected in 86% of the isolates with the disk induction method. Conclusion: The results we obtained in our study are consistent with other researchers globally and in Turkey. It was concluded that there is a need for well-standardized phenotypic tests with defined evaluation criteria and further studies to verify these tests genotypically.


Author(s):  
F. Z. Uyanga ◽  
E. O. Ekundayo ◽  
E. O. Nwankwo ◽  
A. I. Inimfon

Background/Purpose: The aim of this study was to evaluate the effectiveness of CHROMagar ESBL in comparison with Double Disc Synergy Test (DDST) for the detection of ESBL producing uropathogens. Methods: Six hundred and sixty urine samples were collected from pregnant women attending antenatal at General hospital Ikot Ekpene, Eket and Oron. Two hundred and fifty eight isolates were obtained while two hundred and thirty one isolates were ESBL producers. Microbact 24E(Oxoid, UK) was used in the identification of bacterial isolates, antibiotic susceptibility test was done using Kirby-Bauer disk diffusion method following CLSI guidelines using commercially available disc (Oxoid Ltd). Double disk synergy test was carried out on the isolates and inoculation was done using CHROMagar ESBL (France). Results: The prevalence of ESBL 35% was recorded. The sensitivity and specificity of DDST was 88% and 89%, respectively. CHROMagar showed an increase in sensitivity and specificity at 48 h with 98% and 99.0%, respectively. 80% of the ESBL producing isolates were multi drugs resistant. The predominant bacterial pathogens were Enterobacter cloacae (23%), Proteus mirabilis (14%) and Acinetobacter baumanii (13.4%).The ESBL producing isolates showed maximum resistance against Ceftazidime (90%), Cefotaxime (91%), Azetronam (95%), Amikacin (68.2%) followed by ofloxacin (70%) while maximum sensitivity was seen for imipenem (90%) and Augumentin (80%). The study demonstrated that CHROMagar was superior and more sensitive than DDST. Conclusion: CHROMagar ESBL seems to be the most reliable method among phenotypic methods for detection of ESBL in the absence of PCR.


Sign in / Sign up

Export Citation Format

Share Document