Search published articles


Showing 8 results for Esbl

Mahsa Yazdi, Ali Nazemi, Mir Saed Mir Nargasi, Mr Khataminejad, Sh Sharifi, M Babai Kochkaksaraei,
Volume 4, Issue 1 (4-2010)
Abstract

Abstract Background and objectives: Beta-lactamase enzymes are the most causes of resistance to antibiotics among gram-negative bacteria. Nowadays, Infections due to ESBLs are being increased throughout the world and is considered as a new burden to the health systems. This study aimed at determining the sensitivity pattern of E.coli isolates to beta-lactam antibiotics, and investigating the presence of blaCTX-M, blaTEM, and blaSHV genes in the urine samples. . Material and Methods: In this study, 244 E.coli isolates were screened in 2009-2010. The antibiotic susceptibility of E. coli isolates were determined by disc-diffusion method. Antimicrobial agents tested were cefoxatime, ceftazidime, imipenem, nalidixic acid, and ciprofloxacin. The combined disc test was used to confirm the results. The results were compared to the Clinical and Laboratory Standards Institute (CLSI) and ESBL positive isolates were further investigated for the presence of blaCTX-M, blaTEM, and blaSHV genes by PCR. Results: Of 244 E. coli isolates, 116 (47.1%) are resistant to Ceftazidime, and 96 (39.2%) to cefoxatime. Also, 109 (44.3%) isolates are ESBL positive. blaCTX-M, blaTEM, and blaSHV genes are found among 95 (87.1%), 75 (68.8%), and 77 (70.6%) ESBL positive isolates, respectively. Forty (36.6%) isolates have all three genes, while 68 (62.3%) include blaTEM and blaSHV genes. Moreover, 61 (55.9%) isolates carry blaCTX-M and blaTEM genes, and 54(49.5%) have blactx-M and blashv. Conclusion: Regarding the high frequency of resistance to the third generation cephalosporin antibiotics, precise antibiogram testing is highly recommended before any antibiotic prescription in cases of infections with ESBL producing microorganisms. Key words: ESBL Escherichia coli blaCTX-M blaTEM blaSHV.
Doudi M, Naghsh N, Heiedarpour A,
Volume 5, Issue 2 (10-2011)
Abstract

Abstract: Background and objectives: Antibiotic resistant to Antimicrobial agents is one of the most important concern in hospitals, which can lead to increased costs, treatment fails and mortality rates. The aim of this study was identification of Gram-negative bacilli resistant to extended-spectrum β-lactamase Enzymes (ESBLs) and determination of the effect of silver nanoparticles on them. Materials & Methods: of 276 clinical samples referred to three hospitals of Isfahan city, 186 gram negative bacilli were studied. To recognize ESBLs production, the bacilli was assessed by disk diffusion method and confirmed by DDT and Double Disk approximation Test. The ESBL producing bacteria were subjected to increasing concentrations (12.5, 25, 50,100,200,400 and 500 ppm) of silver nanoparticles, prepared in Tehran Nano Pars Company, and Inhibitory zone diameter was measured. Results: of 186 isolates, 140 (%75/3) are gram-negative bacilli producing ESBLs and 46 (24.7%) of them without this capability. Most of ESBLs bacteria are belonged to urine infections and the most prevalent bacterium is Klebsiella pneumonia. All samples are sensitive to the nano silver solution with density of 100 ppm. Enterobacter aerogenes (24 mm) and Pseudomonas aeruginosa (23mm) have the greatest Inhibitory zone diameter in the presence of 500 ppm of silver nanoparticles. Conclusion: It seems that silver nanoparticles have inhibitory effect on all studied gram negative bacilli. The inhibitory effect of silver nanoparticles against ESBL producing Gram negative bacteria is dose depended Keywords: Gram-negative bacilli, ESBLs, silver nanoparticles.
Babaii Kochaksaraii M, Nasrolahiomran A, Javid N, Shakeri F, Yazdi M, Ghaemi E A,
Volume 6, Issue 1 (4-2012)
Abstract

Abstract Background and objectives: The increase of ESBL producing E.coli can create a tremendous difficult y for the health system. These isolates leads to rapid transmission of causative genes to other clinically important bacteria and synchronously increased resistant to other antibiotics. This study was carried out to determine the prevalence of this isolate and related genes in Gorgan, North of Iran. Material and Methods: This study was conducted on 218 isolated E.coli from urinary tract infection of outpatients referring to six medical laboratories in Gorgan, during 2010-11. The resistance to Cefotaxim (Mast Co.) was assessed by Kirby-Bauer disk diffusion method. The confirmatory test for detection of resistant isolates was carried out by double disk method at the presence of Cefotaxim and clavulanic acid. The presence of β lactamase gene of blatem, blactx and blashv in ESBL was assessed by PCR method. Results: of 218, 70 isolates (32.1%) are resistant to Cefotaxim. Sixty-two (88.6%) of them are confirmed as ESBL producing E.coli. β lactamase genes of blactx, blatem and blashv can be seen in 28(45.2%), 26(41.9%) and 6(9.7%) isolates, respectively. Conclusion: the prevalence of ESBL producing E.coli in Gorgan is in the range of country average and blaCTX-M gene is the most common gene. Key words: E.coli, ESBL, bla gene, UTI
H Mahmoudjanlou, K, A Moradi, F Shakeri, M Babaii Koochaksarii, N Mansoor Samae,
Volume 6, Issue 2 (10-2012)
Abstract

Abstract Background and objectives: the increasing use of antibiotics, especially the third generation cephalosporins, is an important factor in the spread of antibiotic resistance in bacteria. The main reason for the development of resistance phenotype such as Extended Spectrum Beta Lactamas (ESBL) is the extensive use of broad-spectrum cephalosporins. In phenotypic survey, the Phenotyping confirmatory test and the minimum inhibitory concentration (MIC) are used. In this study, the prevalence of the isolates resistant to third generation cephalosporin (cefotaxime) was determined based on MIC. Material and Methods: form September 2010 to September 2011, 75 isolates of Klebsiella pneumoniae were collected from the infections of inpatients and outpatients, referred to state and private laboratories of Gorgan. For all of the Klebsiella pneumoniae strains, MIC determination using E-test (company Liofilcheme-Italy) was performed. Results: According to the MIC results, 26 samples (34.6%) are resistant to cefotaxime 22 isolates are completely resistant to concentration of 256μg. Conclusion: Because of the importance of risk of becoming ESBL, further studies are needed to clarify the ESBL in the region. Keywords: ESBL, MIC, Klebsiella pneumoniae, Cephalosporin
Mahmoudjanlou, H, Ghazisaeedi, K, Shakeri, F, Ghaemi, Ea,
Volume 8, Issue 5 (1-2015)
Abstract

Abstract Background and Objective: Klebsiella pneumoniae is one of the agents causing nosocomial infection therefore, we decided to report the prevalence of Klebsiella pneumoniae caused infection. Material and methods: The frequency of Klebsiella in culture media samples of Panje Azar hospital was studied in 2011-2012. After determination of the species with biochemical methods and determination of resistance to third generation cephalosporins, the existence of responsible genes for this resistance was investigated using specific primers. The PCR product for CTX-M gene was sequenced. Results: During the study, 70 isolates of Klebsiella were isolated in that 51 (72.8%) related to three months of November, December and January. Except for the one related to November, other ESBL cases belonged to these three months. Based on molecular investigation of ESBL genes, these isolates at least were in 3 types and had a high frequency in Internal, female and Emergency wards. Conclusion: The present report implied a sudden prevalence of Klebsiella pneumoniae that detected and controlled by a correct monitoring. Keyword: Klebsiella Pneumoniae, ESBL, CTX-M
Roya Rafiee , Fereshte Eftekhar , Seyed Ahmad Tabatabaei , Dariush Minaee-Tehrani ,
Volume 10, Issue 3 (5-2016)
Abstract

ABSTRACT

       Background and Objectives: Pseudomonas aeruginosa is the most frequent opportunistic pathogen isolated from the sputum of patients with cystic fibrosis (CF). Resistance to β -lactam antibiotics may arise from over expression of the naturally occurring AmpC cephalosporinases or acquired extended-spectrum β-lactamases (ESBL). The aim of this study was to determine the antibiotic resistance profiles as well as the prevalence of ESBL and AmpC production in clinical isolates of P. aeruginosa from CF patients in Tehran.

         Methods: Antibiotic resistance of 50 non-duplicate P. aeruginosa isolates was determined by the disc diffusion method. AmpC β-lactamase production was detected by the antagonism disc test and ESBL production was detected by the phenotypic confirmatory test. The presence of ESBL and AmpC genes was assessed by PCR, followed by sequencing the PCR products.

         Results: The antibiotic resistance rates were as follows: 22% to ceftriaxone, 20% to cefotaxime, 10% to imipenem, 8% to carbenicillin and 6% to ticarcillin, 4% each to cefepime, tobramycin, amikacin and aztreonam and 2% to each piperacilin, meropenem and ceftazidime. AmpC production was observed in 47 isolates (94%) and ESBL production was observed in one isolate (2%). PCR results showed that all isolates carried the blaAmpC β-lactamase gene. One multidrug-resistant isolate carried both blaTEM and blaPER-1 genes.

        Conclusion: The results showed that despite the low rate of antibiotic resistance in P. aeruginosa CF isolates,the  presence of multiple β-lactamases even in one isolate is alarming and can complicate the already difficult treatment of chronic infections in the lungs of CF patients.

         


Mohammad Faezi Ghasemi , Seyede Negin Dibadji,
Volume 10, Issue 5 (9-2016)
Abstract

ABSTRACT

      Background and Objective: Extended-spectrum beta-lactamases (ESBL) are widely produced by Escherichia coli strains. The aim of this study was to determine frequency of blaOXA-1 and blaSHV genes in E.coli strains isolated from patients hospitalized in city of Rasht, Iran.

       Methods: In this cross-sectional study, 200 samples were collected from patients. The E. coli strains were identified using morphological characteristics and biochemical tests. Antimicrobial susceptibility testing was performed. The prevalence of the blaOXA-1 and blaSHV genes in the E. coli isolated was assessed by PCR method.

       Results: Overall, 160 E. coli strains were isolated. Of these, 83 (51.9%) showed ESBL activity while 71 (48.1%) did not. All positive strains were resistant to cephalothin. Moreover, 98.8% of ESBL-producing strains were resistance to amoxicillin, cefotaxime and ceftriaxone. The prevalence of the blaOXA-1 and blaSHV genes in ESBL-producing strains were 45% and 17%, respectively. In addition, 28.9% of the strains had both genes while the genes were absent in 9.6% of the strains.

      Conclusion: Prevalence of the blaOXA-1gene is higher than that of the blaSHV gene. The absence of both genes in some isolates indicates the possible role of other genes in the ESBL activity.

      Keywords: Prevalence, ESBLs, Escherichia coli, blaOXA-1gene, blaSHV gene.


Majid Komijani , Majid Bouzari , Fateh Rahimi ,
Volume 11, Issue 2 (3-2017)
Abstract

ABSTRACT
       Background and Objective: Escherichia coli is one of the most common causes of hospital-acquired infections. Extended-spectrum β-lactamase (ESBL)-producing E. coli strains are resistant to third-generation cephalosporins. The three main genes involved in ESBL production are TEM, SHV and CTX-M. Detection of ESBL-producing E. coli is of importance for infection control, reduction of excessive antibiotic use and epidemiological surveillance. This study aimed to detect ESBL-producing E. coli strains isolated from wound infections using phenotypic and molecular methods.
       Methods: During 2013- early 2015, 86 strains were collected from three hospitals in Isfahan, Iran. Antibiotic susceptibility testing was done using ceftazidime and ceftazidime + clavulanic acid discs. Polymerase chain reaction was used for the detection of the three resistance genes.
      Results: The resistance genes SHV, CTX-M and TEM were detected in 49 isolates (56.9%). In addition, 39 isolates (45%) were ESBL-producing strains. According to the results, 5 (5.8%), 14 (16.2%), 19 (22%) and 11 (12.7%) isolates contained the SHV, CTX-M, TEM and CTX-M + TEM genes, respectively. The frequency of CTX and TEM were significantly higher than that of SHV gene (P <0.05). Most of the isolated bacteria were resistant to cefazolin and sensitive to nitrofurantoin.
       Conclusions: There is a difference between the frequency of ESBL-positive isolates reported in the phenotypic and genotypic methods, which could be due to the lower sensitivity of the phenotypic method and impact of environmental factors on the emergence of antibiotic resistance.
       Keywords: Antibiotic resistance genes, ESBL, TEM, SHV, CTX-M, Escherichia coli.


Page 1 from 1     

© 2007 All Rights Reserved | Medical Laboratory Journal

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.