Journal title

fa بررسی شیوع و شناسایی انواع کارباپنمازهای تولید شده توسط اشریشیا کلی و کلبسیلا نومونیه جدا شده از بیماران مراجعه کننده به مراکز درمانی ایلام به روش فنوتیپی و ژنوتیپی Identification of Carbapenemase genes and evaluation of their prevalence among E.coli and Klebsiella pneumoniae Isolated from patients who admitted to Ilam hospitals by phenotypic and genotypic method عمومي General مقطعی (Cross sectional) Cross sectional برای انتخاب درمان آنتی بیوتیکی مناسب و جلوگیری از گسترش روز افزون سویه های مقاوم به کارباپنم ها و جلوگیری از انتقال آنها به سایر سویه های باکتریایی و همچنین جهت طراحی و ساخت آنتی بیوتیک ها و حتی واکسن های جدید بر علیه سویه های مولد کارباپنمازها، این چنین مطالعاتی مبنی بر بررسی باکتری های تولید کننده کارباپنماز و شناسایی الگوی انواع کارباپنمازهای تولید شده امری ضروری به نظر میرسد.  از آنجا که در کشورعزیزمان ایران مطالعه جامعی مبنی بر بررسی شیوع و شناسایی انواع کارباپنمازهای تولید شونده توسط باکتری های اشریشیا کلی و کلبسیلا نومونیه انجام نشده است لذا هدف از این مطالعه بررسی شیوع و شناسایی کارباپنمازهای تولید شده توسط اشریشیا کلی و کلبسیلا نومونیه جدا شده از بیماران مراجعه کننده به مراکز درمانی ایلام بالینی میباشد.  مهمترین یافته ها: فراوانی ژن های دخیل در مقاومت به انتی بیوتیک های بتالاکتام  در درمان عفونت های حاصل باکتری های ذکر شده قابل ملاحظه می باشد. به طوری که در درصد بالایی از جدایه های کلبسلا پنمونیه و اشرشیا کلای، آنزیم کارباپنماز ردیابی گردید.  پیشنهاد برای کاربرد نتایج:  ارائه الگوی مقاومت به جامعه پزشکی جهت بکار گیری درمان موثرتر باکتری های مقاوم به بتالاکتم Abstract Objectives: Drug resistance among gram-negative bacteria is a worldwide challenge. Due to the importance of drugresistant Klebsiella pneumoniae and Escherichia coli strains in hospital-acquired infections, we aimed to determine the phenotypic and genotypic characteristics of ESBL-, AmpC-, and carbapenemase-producing isolates obtained from hospitalized patients in Tehran and Ilam (Iran). Materials and Methods: In total, 90 K. pneumoniae isolates and 65 E. coli isolates were collected from various infections. Phenotypic identification of bacterial isolates was performed using standard methods. Phenotypic screening of ESBL, AmpC, and carbapenemase enzymes was carried out. Detection of ESBL, AmpC, and carbapenemase genes was also performed by the PCR method. Results: Phenotypic detection tests showed that 36 (40%) K. pneumoniae and 23 (35.4%) E. coli isolates were ESBL producers. Moreover, 18 (20%) and 6 (9.2%) K. pneumoniae and E. coli isolates were AmpC producers, respectively. Modified Hodge test results indicated that 39 H.K. and H.H. contributed equally to this work as first authors. This is an Open Access article licensed under the Creative Commons Attribution-NonCommercial-4.0 International License (CC BY-NC) (http://www.karger.com/Services/OpenAccessLicense), applicable to the online version of the article only. Usage and distribution for commercial purposes requires written permission. 2 Med Princ Pract Kazemian et al. DOI: 10.1159/000500311 (43.3%) K. pneumoniae and 18 (27.7%) E. coli isolates produced carbapenemase. Molecular tests showed that 40% of K. pneumoniae and 36.9% of E. coli isolates were ESBL positive. AmpC was detected in 24.4 and 13.8% of K. pneumoniae and E. coli isolates. Carbapenemase was detected in 34 (37.8%) K. pneumoniae and 13 (20%) E. coli isolates. Conclusion: In this study, 3 K. pneumoniae isolates simultaneously carried ESBL, AmpC, and carbapenemase genes. Upto- date strategies such as combination therapy or utilization of new antimicrobial agents might help to combat such drug-resistant organisms. © 2019 The Author(s) Published by S. Karger AG, Basel Introduction Drug resistance in gram-negative bacteria is a worldwide challenge [1]. Major resistance to gram-negative pathogens is related to Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa [2]. In the Enterobacteriaceae family, Klebsiella pneumoniae and Escherichia coli have notable drug resistance. Also, they are the common cause of hospital- and community-acquired infections [3, 4]. The wide distribution of extended-spectrum β-lactamases (ESBLs) amongst Enterobacteriaceae has been attributed to the over- or misuse of these antibiotics [5]. ESBLs are able to hydrolyze various types of β-lactam antibiotics, including cephalosporins and monobactams. Therefore, treating infections caused by ESBL-producing bacteria has become a complicated issue [5, 6]. Dissemination of hospital-acquired infections can be prevented via early detection of infections caused by such microorganisms [7]. Carbapenems have been considered as the treatment of choice for ESBL-producing gram-negative bacterial infections. Carbapenemase-producing strains cause serious infections in hospitalized patients and are associated with mortality [8]; hence, the use of molecular techniques could be helpful in accurately diagnosing infections caused by ESBL- and carbapenemase-producing organisms. Drug-resistant strains of K. pneumoniae and E. coli in hospital-acquired infections are important [9]; thus, the aim of the present study was to determine the phenotypic and genotypic characterization of ESBL-, AmpC-, and carbapenemase-producing isolates of K. pneumoniae and E. coli obtained from hospital-associated infections in Tehran and Ilam (Iran). Materials and Methods Bacterial Strains A total of 90 K. pneumoniae and 65 E. coli isolates were obtained from various infections of hospitalized patients between April 2016 and March 2017 in Tehran and Ilam. Phenotypic and biochemical identification of bacterial isolates was performed according to standard methods [10]. Phenotypic Screening of ESBL, AmpC, and Carbapenemase Enzymes All isolates were initially screened for ESBL production by a combined disk method according to the guidelines of the Clinical Laboratory Standards Institute (CLSI) [11]. Briefly, susceptibility to cefotaxime (30 μg), cefotaxime/clavulanate (30/10 μg), ceftazidime (30 μg), and ceftazidime/clavulanate (30/10 μg) (Mast Co., UK) was determined on Müller-Hinton agar (Merck Co, Germany). ESBL-producing strains were recognized by an at least 5-mm increase in zone diameter around cefotaxime/clavulanate and ceftazidime/clavulanate disks in comparison with disks without clavulanic acid. E. coli ATCC 35218 was used as the control strain [11]. Cefoxitin disks (30 μg) were used to screen AmpC-producing isolates according to CLSI recommendations [11]. A cefoxitincloxacillin double-disk synergy test was carried out to confirm AmpC production, as previously described [12]. The modified Hodge test (MHT) was performed to screen carbapenemase- producing isolates [11]. K. pneumoniae ATCC BAA- 1705 and BAA-1706 were used as MHT-positive and -negative controls [11]. Detection of ESBL-, AmpC-, and Carbapenemase-Related Genes Polymerase chain reaction was performed using specific primers to detect genes encoding ESBLs (blaTEM, blaSHV, blaCTX-M, and blaPER), AmpC (blaACC, blaDHA, blaEBC, blaFOX, blaMOX, and blaCIT), and carbapenemase (blaIMP, blaVIM, blaNDM, blaKPC, and blaOXA-48-like), as previously described [13–17]. The products were separated by electrophoresis in 1% agarose gel with 1× TBE (Tris/ borate/EDTA) buffer, stained with safe stain load dye (CinnaGen Co., Tehran, Iran) and visualized under ultraviolet illumination. Statistical Analysis The distribution of resistance genes among resistant and susceptible isolates was calculated using χ2 and Fisher’s exact tests for each gene. p values ≤0.05 were considered to be statistically significant. کارباپنماز, اشریشیا کلی , کلبسیلا نومونیه Klebsiella pneumoniae · Escherichia coli · ESBLs · AmpC · Carbapenemase 0 0 http://newresearch.medilam.ac.ir/browse.php?a_code=A-10-3001-3&slc_lang=fa&sid=1 Iraj Pakzad ایرج پاکزاد pakzad_i2006@yahoo.com 4539274457 100319475328460049329 Yes Clinical Microbiology Research Center, Ilam University of Medical sciences, Ilam, Iran مرکز تحقیقات میکروب شناسی بالینی، دانشگاه علوم پزشکی ایلام، ایلام، ایران Hossein Kazemian حسین کاظمیان h.kazemian@outlook.com 4501161371 100319475328460049330 No Department of Microbiology, School of Medicine, Ilam University of Medical sciences, Ilam, Iran گروه آموزشی میکروب شناسی، دانشکده پزشکی، دانشگاه علوم پزشکی ایلام، ایلام، ایران