Resistant microbial strains are a serious threat to public health in different societies. A mong the extended-spectrum β-lactamases (ESBL) producing strains the Enterobacteriaceae family which is considered as the main factors producing urinary tract infections, have created many problems in treatment of this kind of infections. This study was conducted to determine the frequency of β-lactamase TEM-1 gene in Enterobacteriaceae isolated from urine samples in Ardabil city. Within 6 months, 400 urinary isolates of Enterobacteriaceae of inpatients and outpatients were collected in Ardabil hospitals and were identified by standard methods. Antimicrobial susceptibility of isolates was tested by disk diffusion method, and ESBL producer confirmatory test was conducted using combined disk. Finally, the frequency of β-lactamase TEM-1 gene in producing extended-spectrum β-lactamases strains was investigated using PCR. From 400 isolates of Enterobacteriaceae, 150 cases (37.5%) were ESBL producing. PCR results showed presence of the TEM-1 gene in 69 cases (46%). The frequency of this gene in isolates of Enterobacter (Aerogenes, Cloacae), Klebsiella (Pneumoniae, Oxytoca) and E. coli was obtained to be 62.5%, 54.5% and 44.8%, respectively. Proteus mirabilis and Serratia marcescens strains were lacking these genotypes. As regards the presence of TEM-1 gene, there is also increasing in other members of the Enterobacteriaceae family including Klebsiella and Enterobacter in addition to E. coli, therefore sufficient identification of this strains is necessary to prescribe the right medicine.

β-lactamase enzymes producing bacteria ESBL have spread widely throughout the world. The production of enzymes induces bacterial resistance to a wide range of antibiotics which is leading to the limitation of infection control and correct treatment. The aim of the present study was to investigate patterns of antibiotic susceptibility to antibiotics and the presence of β-lactamase genes SHV، TEM، CTX-M، in Klebsiella pneumoniae isolates from clinical specimens of intensive care. Susceptibility of isolated bacteria against 10 antibiotics was determined by agar disk diffusion method according to the CLSI guidelines. The strains (DDST) were examined for the presence of the spectrum β-lactamase enzymes. Using E-test، the minimum inhibitory concentration (MIC) of the antibiotic was determined to cefotaxime. Moreover، SHV، TEM، CTX-M genes were identified by، Multiplex PCR method، and some of them were sequenced. The antibiotic resistance against 10 antibiotics was determined. The highest percentage of isolates was resistant to ampicillin (100%) and sensitivity to imipenem was 1. 66%). In this study، the majority of strains produced ESBL (60%). TEM gene in 34. 38% and all three genes (TEM and SHV and CTX) at 33. 13% of isolates were observed. The present study showed that the K. pneumoniae producing ESBL in patients in ICU are common. Therefore، the use of procedures and policies for infection control in hospitals and especially ICU is necessary.

The occurrence of extended-spectrum beta-lactamases-producing bacteria is an important public health issue. The aim of this study was to investigate phenotypic and genotypic characteristics regarding the presence of extended spectrum β-lactamase ctx-m, per and ver producing Escherichia coli isolated from raw dairy samples. For this purpose, E. coli were isolated from 247 raw dairy samples (milk and cheese) in Yasooj in 2015-2017, and the isolates were screened for antibiotic resistance, extended spectrum β-lactamase and the presence of ctx-m, per and ver. In total, 200 isolates were selected. The highest frequency of resistance in isolates was against tetracycline (96.5%) and ampicillin (95.5%) antibiotics and the lowest against imipenem (12.5%), In addition, multidrug resistance against four or more antibiotics was observed in some isolates. Extended spectrum β-lactamase resistance was detected in 86 isolates (43%) and ctx-m, per and ver genes were detected in 82, 0 and 7 E. coli isolates, respectively. These findings demonstrated that raw dairy products may be reservoirs for the dissemination of β-lactam antibiotics and that resistance genes could be transmitted to humans through the food chain.

Extended-spectrum beta-lactamase (ESBL) enzymes hydrolyze cephalosporins and penicillins. This study aimed to determine the frequency of Escherichia coli strains producing SHV, TEM and CTX-M β-lactamase genes and their association by inducing antibiotic resistance. In this cross-sectional study, 55 E. coli strains were isolated from urinary samples and cultured on eosin methylene blue (EMB) agar and CHROMagar. After biochemical examinations, antibiotic susceptibility test was performed using the disk-diffusion method according to the guidelines of the Clinical & Laboratory Standards Institute (CLSI). In addition, the presence of blaCTX-M, blaTEM and blaSHV genes was evaluated using specific multiplex polymerase chain reaction (PCR) primers. In this study, the highest antibiotic resistance was observed against penicillin and erythromycin (96% and 94.5%, respectively), while the highest susceptibility was reported for ciprofloxacin and imipenem (67.2%). Out of 55 samples, 26(47.27%) had the TEM gene, and CTX-M gene was detected in 41 (74.54%) samples. Moreover, TEM and CTX-M genes were simultaneously detected in 32.72% of the samples, while in six samples (10.9%), neither of these genes were present. The SHV gene was not detected in any of the samples. According to the results of this study, the production of ESBL was identified in 70% of the investigated E. coli isolates. Therefore, accurate and timely medical care, as well as the use of appropriate antibiotics, is required to prevent the outbreak of ESBL-producing E. coli strains.

One of the most common infections in patients with high mortality rate is ventilator-dependent pneumonia. This study aimed to determine the frequency of extended spectrum beta-lactamase (ESBL) in Klebsiella pneumonia isolated from patients with ventilator-associated pneumonia in Kermanshah City, Iran.
This study performed on tracheal tube samples of patients admitted to the intensive care units. After collecting specimens, 57 Klebsiella pneumonia isolates were confirmed via standard bacteriological and biochemical tests. After antibiotic susceptibility testing by using disk diffusion method, the presence of ESBL phenotype was determined via combined disk test. The frequency of ESBL genes was determined by using their specific primers and polymerase chain reaction (PCR) method.
Findings: From 57 isolates of Klebsiella pneumonia, 22 (38.6%) were positive for ESBL, phenotypically. The highest genotype frequency was shv gene (31.6%) determined via PCR test. The highest resistance was to ceftriaxone and co-trimoxazole (78.9%), and the lowest resistance was to colistin (3.5%).
Considering the high resistance of Klebsiella isolated from samples of patients with ventilator- associated pneumonia against third-generation cephalosporin and the prevalence of ESBL-producing strains among these patients, identification of isolates with ESBL and suitable antibiotic selection for the treatment of this patients seem to be necessary.

Escherichia coli (E. coli), as the main cause of urinary tract infections among most of the age groups including children, due to extended-spectrum beta-lactamases (ESBL) producing has high ability to acquire antibiotic resistance. The purpose of this study was to determine the frequency of ESBL-producing genes in E. coli extracted from urine samples of children in Kermanshah City, Iran.
In this cross-sectional study, 95 E. coli isolates were identified via specific biochemical methods. After determination of antibiotic susceptibility using disk diffusion, ESBL-producing isolates were determined by using phenotypic combined disk (double-disk synergy) methods. The frequency of blaTEM, blaCTX-M, and blaSHV genes were determined via using specific primers and polymerase chain reaction (PCR) method.
Findings: Of 95 E. coli isolates, 24 samples (25.3%) were ESBL-positive and 71 (74.7%) were ESBL-negative samples. The frequency of blaCTX-M, blaTEM, and blaSHV genes was 47.5%, 37.5%, and 4.17%, respectively. The highest antibiotic resistance among isolates was to ampicillin (83.2%), cefixime (69.5%), and trimethoprim/sulfamethoxazole (co-trimoxazole) (67.4%), and the most antibiotic sensitivity was to imipenem (90.5%), norfloxacin (86.3%), and nitrofurantoin (83.2%).
The results showed that prevalence of ESBL-producing E. coli in children was 25.3% and blaCTX-M gene was the most common. According to these findings and relatively high level of resistance to third-generation cephalosporins, the need for more medical care in the correct and appropriate use of antibiotics is concluded; further studies on this subject are recommended, too.

The acquisition of extended spectrum β-Lactamases (ESBL) has made Klebsiella pneumoniae resistant to various types of antibiotics. The aim of this research was to determine the antibiotic resistance pattern and the frequency of TEM, SHV, CTX-M, and PER genes in K. pneumonia strains isolated from Kermanshah medical centers.
In this analytical cross-sectional study, a total of 165 different samples of patients, were collected from three hospitals (Imam Reza, Imam Khomaini, and Taleghani) and a medical diagnostic laboratory (Reference laboratory) in Kermanshah city during 2014-2015. Among them, 100 isolates of K. pneumoniae were confirmed using API-20E kit. Antibiotic susceptibility test was performed by disk diffusion method and phenotypic screening test for ESBL production, was performed by combination disc. After extraction of bacterial genome, CTX-M genes (CTX-M-1 and CTX-M-9 groups), TEM, PER, and SHV were examined by PCR. Then, a number of PCR products were sequenced and analyzed using BLAST software.
Forty percent of the isolates were ESBL-producing and were 100% resistant to third generation of cephalosporins. The isolates of ICU and burn ward patients had a high prevalence of ESBL. The frequency of TEM, CTX-M-1, CTX-M, and SHV genes, were 28%, 32%, 35%, and 83%, respectively, but PER and CTX-M-9 group genes, were not found among the isolates.
The results of this study indicated that the dissemination of ESBL-producing K. pneumoniae isolates, has increased in the isolates from inpatients and outpatients in Kermanshah. Therefore, it can be concluded that multidrug resistant isolates have increased, especially in wards, where patients are hospitalized for a long time. Therefore, identification of ESBL-producing K. pneumoniae strains in medical diagnostic laboratories, seems necessary.

Due to importance and prevalence of ESBL producing isolates in nosocomial infections, this study was undertaken with the aims to determine antibiotic susceptibility patterns,identification of ESBL producing isolates and detection of blaCTX, blaTEM of Acinetobacter spp in clinical isolates from selected Tehran hospitals. Ninety five isolates of Acinetobacter were collected from Tehran’s hospitals.Susceptibility patterns of various antibiotics and MIC for ceftazidime were determined by disk diffusion and microbroth dilution methods respectively based on CLSI protocols. The ESBL producers were screened by phenotypic confirmatory test. PCR was used for detection of blaCTX and blaTEM genes. The lowest and highest resistance rates to investigated antibiotics were seen against colistin (4.2%) and cefexime (100%) respectively. By using PCT, 18.9% of the isolates were ESBL positive. About 83.1 % of Acinetobacter isolates showed MIC ≥ 64 μg/ml to ceftazidime, however only 18.9% of isolates were ESBL producer. Based on the results from PCR technique,1.2% and 12.8% of the isolates were TEM and CTX positive respectively. The rate of MIC to ceftazidime and presence of blaTEM and blaCTX among ceftazidime resistant isolates was very noteworthy in present study. Since less than one fifth of the isolates in present study were ESBL producer, it seems that apart from beta-lactamases, other resistance mechanisms such as efflux pumps and impermeability of the cell membrane may be responsible for this situation.As resistance factors are located on mobile elements, identification and detection of strains producing these enzymes is important in preventing of the expansion of these isolates

Background and Plasmid-medicated quinolone resistance (PMQR) genes play an important role in resistance to quinolones. The aim of this study was to determine the frequency of PMQR genes in extended-spectrum β-lactamase-producing (ESBL) Escherichia coli.
This study was done on 240 isolates of E.­coli from urine samples of patients in Kermanshah, Iran. The susceptibility of isolates to selected antibiotics was tested using disc diffusion and broth microdilution methods. The isolates were screened for ESBL-producing phenotype by combined disc diffusion test. The qnrA, qnrB, qnrS, aac (6­')­-­Ib, and qepA genes were detected by PCR. All PCR products for aac­(6')­-Ib gene were digested by BtsCI for detection of aac­(6')­-Ib-cr variant. Data analysis was done using statistical methods.
Of 66 ESBL-producing isolates, 45 (68.1%) were resistant to ciprofloxacin and levofloxacin and 56 (84.8%) were found to be resistant to nalidixic acid. The qnrA, qnrB, qnrS, and qepA genes were detected in 28.7%, 40.9%, 4.5%, and 3% of the isolates, respectively. The aac­(6')­-Ib gene was found in 65.1% of the isolates amongst which 88.4% were aac­(6')­-Ib-cr variant.
Our results indicate a high prevalence of PMQR genes in ESBL-producing E.coli isolates in Kermanshah. A correlation was observed between resistance to beta-lactams and quinolones which may indicate the cotransfer of quinolone genes by plasmids carrying the ESBL. As a result, identifying E. coli strains with ESBL may indicate a high resistance to quinolones. So, before using quinolones, the screening test for ESBL is recommended to prevent the increasing resistance to this class of drugs.

Escherichia coli is one of the most common causative agent of urinary tract infection. In recent years, resistance to cephalosporins has been considerably on the rise due to production of extended spectrum beta-lactamases (ESBLs.( This study was aimed to determine the survey of CTX-M, SHV, TEM, OXA-1, PER-2, and VEB-1 which are the most famous ESBL genes in E. coli isolated from outpatients with UTI in Guilan.
A total of 2267 urine samples were collected from outpatients suffering from UTIs. After primary biochemical and differential tests like MRVP, Lysin dacarboxilation in LIA medium, Urea hydrolysis test, TSI and Simon citrate test, samples containing E. coli were identified. Antibiotic susceptibilities were determined by disk diffusion. Double disk tests using Cephtriaxon, Amoxiclave and Cephtazidime-clavolonate were performed for phenotypic ESBL production assay. ESBL-producing genes were evaluated by PCR.
Among the 2267 urine samples, 167 E. coli cells were isolated. From these E. coli isolates, 38.9% were shown to be ESBL producers by the Double disk method. Based on the molecular analysis, the frequency of ESBL-producing genes were, CTX-M (70.32%), TEM (9.64%), SHV (4.88%) OXA-1 (57.2%), and PER-2 (12.1%). VEB-1 was not detected in the analyzed samples. Also, some of the isolates had more than one ESBL-producing gene. Statistically, there was a direct correlation between gender and age with the infection.
In this study, more than half of the isolated bacteria were ESBL-producers. As the resistance-inducing genes are carried on mobile genetic elements, rapid detection of resistant species is of major importance to prevent their dissemination.