Search

Introduction: Enterobacteriaceae are a high prevalent gram-negative species worldwide, which play a major role in various infections. Objectives: The present study aims to assess the prevalence of antimicrobial resistance in Enterobacteriaceae at a tertiary hospital in Isfahan, Iran. Materials and Methods: This cross-sectional laboratory-based study was performed during 2020 in Al-Zahra hospital, Isfahan, Iran. The isolates of all of the clinical samples submitted for the bacterial culture containing Enterobacteriaceae strains were checked for antibiotic resistance during March 2018 to March 2019. Results: The results revealed that the specimens obtained from intensive care units (ICUs) exhibited more resistance than the others. Additionally, the highest abundant antibiotic resistance among inpatients was related to ampicillin/sulbactam, and carbapenem resistance was significantly high. Conclusion: The high prevalence of antibiotic resistance indicated the inappropriate antibiotic prescription in this center. The results emphasized the importance of preventive strategies and restrictions in over-the-counter antibiotic consumption.

Background: Staphylococcus aureus (S. aureus) is one of the most important pathogens in burn infections colonized in the nose and increase the risk of infections. Methods: Overall, 85 S. aureus isolates were isolated from clinical and nasal hospitalized patients and health care workers (HCWs) in a burn unit and non-burn units in Isfahan from June 2016 and September 2016. Genes encoding penicillin-binding protein 2a (mecA) and adhesive surface proteins, including fibronectin-binding proteins (fnbA,fnbB), fibrinogen binding protein (fib), laminin-binding protein(eno), collagen binding protein (cna), elastin binding protein (ebps), intracellular adhesion operon (icaA and icaD) were detected using PCR method. Results: The rate of methicillin-resistant S. aureus (MRSA) among burn and non-burn isolates were 62% (18/29) and 25% (14/56), respectively. The most prevalent MSCRAMMs genes in burn units were eno (86%) and fib (66%). The most common gene pattern in burn center was icaA+fib+eno. The frequency of icaD, fib and ebpS was higher in clinical samples than nasal samples. No relation was found between the MSCRAMMs genes in the burn unit and non-burn units. Conclusion: The high prevalence of MRSA in burn center can be a new challenge for clinicians. The higher frequency of icaD, fib and ebpS in clinical isolates than nasal isolates may reflect the important role of these genes in colonization and pathogenesis of S. aureus.

Background: Staphylococcus aureus (S. aureus) is one of the most important pathogens in burn infections colonized in the nose and increase the risk of infections. Methods: Overall, 85 S. aureus isolates were isolated from clinical and nasal hospitalized patients and health care workers (HCWs) in a burn unit and non-burn units in Isfahan from June 2016 and September 2016. Genes encoding penicillin-binding protein 2a (mecA) and adhesive surface proteins, including fibronectin-binding proteins (fnbA, fnbB), fibrinogen binding protein (fib), laminin-binding protein(eno), collagen binding protein (cna), elastin binding protein (ebps), intracellular adhesion operon (icaA and icaD) were detected using PCR method. Results: The rate of methicillin-resistant S. aureus (MRSA) among burn and non-burn isolates were 62% (18/29) and 25% (14/56), respectively. The most prevalent MSCRAMMs genes in burn units were eno (86%) and fib (66%). The most common gene pattern in burn center was icaA+fib+eno. The frequency of icaD, fib and ebpS was higher in clinical samples than nasal samples. No relation was found between the MSCRAMMs genes in the burn unit and non-burn units. Conclusion: The high prevalence of MRSA in burn center can be a new challenge for clinicians. The higher frequency of icaD, fib and ebpS in clinical isolates than nasal isolates may reflect the important role of these genes in colonization and pathogenesis of S. aureus.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) has become a considerable public health concern in the entire world due to the rapid spread of this bacterium in human community; also the epidemiology of MRSA has changed, as the isolation of MRSA strains from healthy and non-healthy patients. Therefore, the objective of this study is to determine the genetic diversity and antibiotic resistance profile of community-acquired (CA)-MRSA nasal carriage in the Iranian samples. Materials and Methods: A total of 25 CA-MRSA were isolated from the anterior nares of 410 healthy preschool children. All MRSA isolates were characterized by the detection of the toxic shock syndrome toxin-1 (TSST-1) and typed by γ-hemolysin genes, agr groups, and staphylococcal protein A (spa) typing. Kirby-Buyer antibiotic susceptibility testing was performed and interpreted as per the standard guidelines. Results: A total of 25 (6.1%) MRSA isolates were recovered from the anterior nares of 410 preschool children. Sixteen isolates (64%) were positive for the TSST-1 gene. Three agr specificity groups were determined, as follows: eight (32%) isolates belonged to agr Group I, five (20%) isolates belonged to agr Group II, and 12 (48%) isolates belonged to agr Group III. The repeated profiles of these spa types of 25 isolates were organized into eight different lineages groups. Five of lineages contained a single strain, three of lineages contained two strains, and three of lineages consisted of more than three strains. Conclusions: The results of our study show that the rate of MRSA in our region is significantly high. Additionally, spa type t037 was the predominant type among CA S. aureus.

Purpose . Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a considerable public health concern in both developed and developing countries due to the rapid spread of this bacterium around the world, also the epidemiology of MRSA has changed, as the isolation of MRSA strains is not limited to health-care settings or patients with predisposing risk factors. Therefore, the objective of this study is to determine the genetic diversity and antibiotic resistance profile of CA-MRSA nasal carriage in Iranian children. Methodology . A cross-sectional study was conducted from April 2013 to March 2014. A total of 25 CA-MRSA were isolated from the anterior nares of 410 preschool children with no risk factors. All MRSA isolates were characterized by detection of the Panton–Valentine leukocidin (pvl) and γ-hemolysin genes, staphylococcal cassette chromosome mec (SCCmec) typing and multi-locus sequence typing (MLST). Results . In 25 CA-MRSA isolates, Pvl and γ-hemolysin genes were detected in one (4%) and 18 (72 %) isolates; respectively. Overall, 92% (23/25) of isolates belonged to SCCmec type IV and 8% (2/25) of them had SCCmec type V profile. Using MLST, the 25 isolates were grouped into six clonal complexes (CC) and eight sequence types (ST) (CC5/ST6, CC22/ST22 and ST217, CC30/ST30 and ST1107, CC78/ST859, CC398/ST291 and CC97/ST405). The ST859/SCCmec IV (11/25, 44%) was the predominant clone among the isolates. ST859-MRSA-IV-pvl-negative (resistant to tetracycline) have successfully adapted to the Iranian preschool children population. Conclusion . Our results suggest that the genomic diversity was observed among the CA-MRSA. In addition, the current study demonstrates that pvl is not a reliable marker for CA-MRSA in our region.

Background: Methicillin - resistant Staphylococcus aureus (MRSA) has become a considerable public health concern in the entire world due to the rapid spread of this bacterium in human community; also the epidemiology of MRSA has changed, as the isolation of MRSA strains from healthy and non-healthy patients. Therefore, the objective of this study is to determine the genetic diversity and antibiotic resistance profile of community-acquired (CA)-MRSA nasal carriage in the Iranian samples. Materials and Methods: A total of 25 CA-MRSA were isolated from the anterior nares of 410 healthy preschool children. All MRSA isolates were characterized by the detection of the toxic shock syndrome toxin-1 (TSST-1) and typed by γ-hemolysin genes, agr groups, and staphylococcal protein A (spa) typing. Kirby-Buyer antibiotic susceptibility testing was performed and interpreted as per the standard guidelines. Results: A total of 25 (6.1%) MRSA isolates were recovered from the anterior nares of 410 preschool children. Sixteen isolates (64%) were positive for the TSST-1 gene. Three agr specificity groups were determined, as follows: eight (32%) isolates belonged to agr Group I, five (20%) isolates belonged to agr Group II, and 12 (48%) isolates belonged to agr Group III. The repeated profiles of these spa types of 25 isolates were organized into eight different lineages groups. Five of lineages contained a single strain, three of lineages contained two strains, and three of lineages consisted of more than three strains. Conclusions: The results of our study show that the rate of MRSA in our region is significantly high. Additionally, spa type t037 was the predominant type among CA S. aureus.

OBJECTIVE To study on antibiotic susceptibility and identify coagulase-negative Staphylococcus (CoNS) species based on tuf gene sequencing from keratitis followed by using soft contact lenses in Isfahan, Iran, 2013. METHODS This study examined 77 keratitis cases. The samples were cultured and the isolation of CoNS was done by phenotypic tests, and in vitro sensitivity testing was done by Kirby-Bauer disk diffusion susceptibility method. RESULTS Thirty-eight of isolates were conveniently identified as CoNS. In this study, 27 (71.1%), 21 (55.3%), and 16 (42.1%) were resistant to penicillin, erythromycin, and tetracycline, respectively. One hundred percent of isolates were sensitive to gentamicin, and 36 (94.7%) and 33 (86.8%) of isolates were sensitive to chloramphenicol and ciprofloxacin, respectively. Also, resistances to cefoxitin were 7 (18.4%). Analysis of tuf gene proved to be discriminative and sensitive in which all the isolates were identified with 99.0% similarity to reference strains, and Staphylococcus epidermidis had the highest prevalence among other species. CONCLUSIONS Results of this study showed that CoNS are the most common agents causing contact lens-associated microbial keratitis, and the tuf gene sequencing analysis is a reliable method for distinguishing CoNS species. Also gentamycin, chloramphenicol, and ciprofloxacin are more effective than the other antibacterial agents against these types of bacteria.

Background: Isfahan Antibiotic Resistance Surveillance System-1 has been instituted in Isfahan, Iran to construct a project for surveillance of clinically significant bacteria, and to help raise a logic regional stewardship program for prevention and control of disseminating-resistant organisms. Methods: During March 2016 to March 2018, an antibiotic resistance surveillance system was designed and implemented by Isfahan Infectious Diseases and Tropical Medicine Research Center. The surveillance program was implemented in three general hospitals in Isfahan. In addition to the routine microbiology data, clinical data (differentiation between true infections and contamination, healthcare-associated infections (HCAI) and community-acquired infections (CAI), as well as determination of the infection site) were obtained and analyzed by WHONET software. Results: During a 2-year period, from 7056 samples that revealed growth of bacteria, 3632 (51.5%) isolates were detected as contamination and 3424 (48.5%) true bacterial isolates were identified. Of these, about 32% of isolates were recognized as HCAI. Totally, the most recognized infections were urinary tract infection, bloodstream infection and skin and soft tissue infections. In patients with HCAIs, 70% of isolates were gram negative and in patients with CAIs 73% isolates were gram negative bacteria. Conclusions: The strength of the project is gathering enough clinical information in addition to microbiologic data, which would increase application of the results for empiric treatment and prevention of the infectious diseases in clinical settings.

Background and Objectives: Staphylococcus aureus is an important pathogen that can be colonized in the nose and increase the risk of spreading infections in hospitals. The present study aimed at determining the phenotypic and genotypic characterization of S. aureus strains isolated from patients and healthcare workers (HCWs) from a teaching hospital in Isfahan, Iran. Materials and Methods: This cross-sectional study was performed on 262 nasal swabs and 23 clinical isolates that were collected from a teaching hospital during February and April 2016. Staphylococcal cassette chromosome mec (SCCmec) and multilocus sequence typing (MLST) were performed for selected isolates. Results: Overall, 23% and 18% of healthcare workers and patients were carriers, respectively. Methicillin-resistant S. aureus (MRSA) rate was 13%, 33% and 52% in nasal HCWs, nasal patients, and clinical samples, respectively. The molecular typing of MRSA isolates revealed that the most common SCCmec type is SCCmec type III (88%). The highest rate of resistance was observed against tetracycline and erythromycin, with 48.7%. The most frequently detected toxin genes among S. aureus isolates were hla (99%) and sea (44%), moreover, pvl genes were detected in (40%) of MRSA isolates. The results of MLST showed 7 different sequence types (STs): ST859 (2/9), ST6 (2/9), ST639 (1/9), ST343 (1/9), ST239 (1/9), ST291 (1/9) and ST25 (1/9). Conclusion: Our results revealed that ST clones associated with healthcare-associated MRSA (HA-MRSA) are actively circulating among nasal carriage in our healthcare setting, and thus, effective infection control policies are needed to reduce nasal carriage in healthcare settings.

Background: Escherichia coli is a Gram-negative, opportunistic human pathogen in which increasing antibiotic resistance is a great concern for continued human survival. Although biofilm formation is a mechanism that helps E. coli to survive in unfavorable conditions, according to the importance of biofilm formation in developing the antibiotic resistance here, we studied the relation between antibiotic resistance and in vitro qualitative rating method biofilm formation in E. coli isolated from patients with urinary tract infection (UTI). Materials and Methods: The clinical isolates of E. coli (n = 100) were collected from urine of patients with UTI attending Isfahan Alzahra hospital. The strains were confirmed as E. coli using biochemical tests and molecular method. The Kirby-Bauer disk diffusion tests were done according to the Clinical and Laboratory Standards Institute protocol, and the biofilm synthesis was performed by microplate method. The binary logistic test was applied and P < 0.05 was considered statistically significant. Results: Our results showed a high outbreak of multidrug-resistant (MDR) E. coli strains (73%) and the highest resistance was observed toward ampicillin. The prevalence of biofilm producer isolates was 80% that 29% produced strong biofilm. The distribution of non-MDR isolates was high among strong biofilm producers, which shows a significant negative correlation between biofilm production and MDR pattern (P < 0.001). Conclusions: We found a negative correlation between MDR phenotype and biofilm formation capacity. This transmits the concept that more antibiotic susceptibility of strong biofilm producers may be due to the reduced exposure to multiple antibiotics.

Background: Extended-spectrum β-lactamase (ESBL)-producing is a significant resistant mechanism to β-lactams in Enterobacteriaceae, especially in Klebsiella pneumoniae. The main objectives of this study were to genetically characterize urinary clinical isolates of K. pneumoniae through the investigating of blaTEM, blaCTX-M and using molecular typing by Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) method. We also determined the frequency of antibiotic resistance of K. pneumoniae strains to characterize the β-lactamases included. Materials and Methods: A cross-sectional study was carried out to evaluate 98 strains of K. pneumoniae isolated from urine culture of outpatients referred to Al-Zahra Hospital, Isfahan, Iran. Antibiotic susceptibility testing was performed using Kirby–Bauer's method. Screening of ESBLs was carried out using double-disk screening test. PCR technique was performed to detect TEM and CTX-M genes. The total DNA of each strain was tested by ERIC-PCR. Results: In 98 K. pneumoniae studied clinical isolates, 25.5% were ESBL producing and 44.9% multidrug-resistant (MDR). From 25 ESBL isolates, 23 (92%) cases showed MDR phenotype. In ESBL producing isolates, 23 (92%) were blaCTX-M and 19 (76%) blaTEM positive. The antimicrobial drug susceptibilities of ESBL isolates indicated high resistant rates for cefotaxime and ceftazidime. All 25 ESBL producing isolates were resistant to cefotaxime. Complex patterns of fingerprints isolates showed that 36% of the isolates were belonged to the cluster no 5. Conclusion: This study revealed high antimicrobial resistance rates among ESBL isolates which can lead to various health difficulties. Epidemiological data collection from patients is recommended to develop the strategies to manage antibiotic resistance.

Background and Objectives: Macrolide, lincosamide and streptogramin B (MLS B) are noteworthy antibiotics for the treatment of Staphylococcus aureus infections. The purpose of this study, was to determine the phenotypic and genotypic characterization of macrolide resistance, among S. aureus, isolated from clinical samples and nasal swabs. Materials and Methods: Totally, 162 non-duplicate S. aureus isolates were collected from clinical samples and nasal swabs, from patients and healthcare workers (HCWs), between March 2016 and September 2016, at four teaching hospitals in Isfahan. The antibiotic resistance profile was determined using disk diffusion test and the presence of resistance genes was detected, using PCR. Results: Of 162 S. aureus isolates, 43.8% (71/162) and 34% (55/162) isolates were erythromycin-resistant and methicillin-resistant S. aureus (MRSA), respectively. The prevalence of constitutive MLS B (cMLS B), inducible MLS B (iMLS B), macrolide-streptogramin B-resistant (MS B) and lincosamide-streptogramin-A resistance (LS A) phenotype was 32%, 6%, 6% and 2%, respectively. The most common erythromycin resistance genes, in S. aureus isolates were ermC (35.2%), followed by ermA (20.4%) and msrA (17.3%). Meanwhile, msrA was detected in 43.6% of MRSA isolates. The frequency of coexistence of ermA+ermC+msrA, in S. aureus isolates was 7% and it was only detected in MRSA isolates. Conclusion: In the current study, cMLS B phenotype was the most common erythromycin resistance pattern and ermC was the most prevalent gene in erythromycin-resistant isolates. The results revealed that the various mechanisms of erythromycin resistance are expanding in Isfahan.

Carriage of S. aureus in the anterior nares seems to play a significant role in the pathogenesis of infection. This study aimed to determine the molecular characteristics and antibiotic susceptibility pattern of S. aureus isolates obtained from the nasal carriage of health care workers (HCWs). This study was performed during July 2014 to July 2015 at three tertiary care hospitals. Nasal samples were collected from the nasal cavity of HCWs. Standard microbiological methods were used for identification of S. aureus isolates. Antibiotic susceptibility pattern was determined by the disc diffusion method. Determination of SCCmec typing and virulence genes was performed by the PCR method. From the isolates of 340 nasal swab samples of HCWs, 65 S. aureus strains (19%) including 22 (33.8%) MRSA were isolated. The highest sensitivity for MRSA isolates was towards vancomycin and rifampicin, each with 90.9%. Overall, 17% (11/65) and 92.3% (60/65) of S. aureus isolates were positive for pvl and hla genes, respectively. The rates of SCCmec types II, III, IV, V and I among MRSA isolates were 36.4 %, 22.7 %, 22.7 %, 9.1% and 4.5% respectively. The results of the present study indicate that S. aureus nasal carriage with potential virulence ability still remains a significant healthcare problem, especially in hospital environments.

Anthropogenic origin pollutants including pesticides, heavy metals, pharmaceuticals and industry chemicals impose many risks to human health and environment and bioremediation has been considered the strategy of choice to reduce the risk of hazardous chemicals. In the current study, we aimed to screen and characterize mycobacteria from the diverse range of Iranian aquatic and terrestrial ecosystems with harsh and unfavorable environmental conditions that can be utilized for biodegradation of target pollutants. Mycobacteria were isolated from a collection of 90 environmental samples and identified to the species level using conventional microbiological and molecular methods including the PCR amplification of hsp65 and sequence analysis of, 16S rRNA genetic markers. The growth rate of the isolates in presence of pollutants, chromatography, Gibbs and turbidometric methods were used to assess their biodegradation activity. A total of 39 mycobacterial isolates (43.3%) were recovered from 90 samples that belonged to 21 various species consisting of M. fortuitum; 6 isolates, M. flavescens and M. paragordonae; 4 isolates each, M. monacense, M. fredriksbergense and M. aurum; 2 isolates each, 7 single isolates of M. conceptionense, M. porcinum, M. simiae, M. celeriflavum, M. novocastrense, M. neoaurum, M. obuense and 12 isolates that belonged to 8 unknown potentially novel mycobacterial species. The isolates were categorized in three groups based on their bioremediation activity, i.e., 5 (12.8%) organisms without biodegradation activity, 20 (51.2%) organisms with previously reported biodegradation activity, and 14 (35.9%) organisms that showed biodegradation activity but not previously reported. Our results showed that the Iranian ecosystems harbor a good reservoir of diverse mycobacterial species with biodegrading potentiality for neutralizing environmental chemical pollutants.

Background: Extended-spectrum β-lactamase (ESBL)-producing is a significant resistant mechanism to β-lactams in Enterobacteriaceae , especially in Klebsiella pneumoniae. The main objectives of this study were to genetically characterize urinary clinical isolates of K. pneumoniae through the investigating of blaTEM, blaCTX-M and using molecular typing by Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) method. We also determined the frequency of antibiotic resistance of K. pneumoniae strains to characterize the β-lactamases included. Materials and Methods: A cross-sectional study was carried out to evaluate 98 strains of K. pneumoniae isolated from urine culture of outpatients referred to Al-Zahra Hospital, Isfahan, Iran. Antibiotic susceptibility testing was performed using Kirby–Bauer's method. Screening of ESBLs was carried out using double-disk screening test. PCR technique was performed to detect TEM and CTX-M genes. The total DNA of each strain was tested by ERIC-PCR. Results: In 98 K. pneumoniae studied clinical isolates, 25.5% were ESBL producing and 44.9% multidrug-resistant (MDR). From 25 ESBL isolates, 23 (92%) cases showed MDR phenotype. In ESBL producing isolates, 23 (92%) were blaCTX-M and 19 (76%) blaTEM positive. The antimicrobial drug susceptibilities of ESBL isolates indicated high resistant rates for cefotaxime and ceftazidime. All 25 ESBL producing isolates were resistant to cefotaxime. Complex patterns of fingerprints isolates showed that 36% of the isolates were belonged to the cluster no 5. Conclusion: This study revealed high antimicrobial resistance rates among ESBL isolates which can lead to various health difficulties. Epidemiological data collection from patients is recommended to develop the strategies to manage antibiotic resistance.

Background: The rapid emergence and spread of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has raised considerable public health concern in both developed and developing countries. The current study aimed to address the extent of this phenomenon in healthy preschool children of a developing country. Materials and Methods: We conducted a prospective study from April 2013 to March 2014 on 410 healthy 2-6 years old preschool children in Isfahan, Iran. Demographic medical data and nasal samples were collected from the participating children. Isolates were identified as S. aureus and MRSA based on microbiological and molecular tests, including the presence of eap and mecA genes. Results: The overall prevalence of S. aureus and CA-MRSA nasal carriage was 28% (115/410) and 6.1% (25/410), respectively. The identity of isolates was confirmed by molecular assay. The factors that were independently associated with nasal carriage of S. aureus were: Children crowding in day-care nurseries and income level of families. A total of 20/90 (22.2%) of methicillin-susceptible S. aureus and all 25 CA-MRSA displayed multiple drug resistance to 3–8 antibiotics. Conclusions: The current report reflects issues and concerns that the high rate of colonization by CA-MRSA in Iranian healthy children provides obliging evidence that MRSA have established a foothold in the community and are emerging as important health threatening pathogens. It is suggested that we need more effective infection control measures to prevent transmission of nasal CA-MRSA in healthy preschool children.

The aim of this study was to apply RAPD technique to analyze the genetic variability among the Iranian CA-MRSA isolates.The RAPD amplification was implemented on 25 strains isolated from the anterior nares of 410 healthy children using four randomly selected oligonucleotide primers from the stocks available in our laboratory, including the primers 1254, GE6, OLP6 and OLP13 from our stock. The amplified PCR products were detected on a 1.5% agarose gel and subjected to further analysis to establish the band profiles and genetic relationships using the Gel Compar® program.The Iranian CA-MRSA isolates produced distinct RAPD patterns which varied based on the primer used, however, the primer 1254 revealed highly polymorphic patterns consisting 5 discernable RAPD types (RT), “RT1” (12, 48%), “RT2” (8, 32%), “RT3” (3, 12%), and “RT4 and RT5”, (a single RAPD type each, 4%). Phylogenetic analysis based on RAPD profiles divided most of the CA-MRSA isolates into 2 distinct but related RAPD clusters, a small group and two single unrelated RAPD types.This study shows that the simple and cost-effective but rather difficult to optimize RAPD fingerprinting could be used to evaluate genetic and epidemiological relationships of CA-MRSA isolates on condition that the patterns are obtained from carefully optimized laboratory tests.

Background: Extended-spectrum beta-lactamases (ESBLs) are a group of enzymes that hydrolyze antibiotics, including those containing new cephalosporins, and they are found in a significant percentage of Escherichia coli and Klebsiella pneumoniae strains. With the widespread use of antibiotics, difficulties with infection therapy caused by drug resistant organisms, especially those that have acquired resistance to beta-lactams, such as broad-spectrum cephalosporins, have amplified the above-mentioned organisms. Objectives: This study was conducted to characterize ESBLs among E. coli and K. pneumonia isolates by molecular and phenotypic methods. Materials and Methods: Different strains of E. coli and K. pneumonia were collected from patients with urinary tract infections. The ESBL phenotype was determined by a double disk diffusion test (DDDT). In addition, polymerase chain reaction (PCR) analysis specific for β-lactamase genes of the TEM and SHV family was carried out. The PCR products were run on agarose and examined for DNA bands. Results: A total of 245 E. coli and 55 K. pneumonia strains were isolated from different samples. In total, 128 of the 300 isolates were confirmed as potential ESBLs producers as follows: 107 (43.67%) E. coli and 21 (38.18%) K. pneumonia. ESBLs genes were found in 24 isolates (18.75%): 21 E. coli and 3 K. pneumonia isolates. The TEM gene was present in 13 (12.14%) E. coli strains, but it was not detected in K. pneumonia. In addition, the SHV gene was present in 8 (7.47%) E. coli and 3 (14.28%) K. pneumonia isolates. Five (4.67%) of the E. coli isolates harbored both TEM and SHV genes. All isolates (100%) were susceptible to imipenem. The lowest rates of resistance to other antibiotics were observed for; piperacillin-tazobactam (6.25%), amikacin (12.5%) and gentamicin (14.84%). The rates of resistance to other antibiotics were as follow: nitrofurantoin (16.4%), nalidixic acid (23.43), co-trimoxazole (25%), cefepime (32%), ciprofloxacin (55.46%), ampicillin (69.53%), ceftazidime (100%), and cefotaxime (100%). Conclusions: The results of this study indicate the widespread prevalence of ESBLs and multiple antibiotic resistance in E. coli and K. pneumoniae. Therefore, beta-lactam antibiotics and beta-lactamase inhibitors or carbapenems should be prescribed based on an antibacterial susceptibility test.

Hand hygiene is the mainstay of nosocomial infection prevention. This study was a baseline survey to assess hand hygiene compliance of healthcare workers by direct observation in three major hospitals of Isfahan, Iran. The use of different hand hygiene products was also evaluated. In 3078 potential opportunities hand hygiene products were available on 2653 occasions (86.2%). Overall compliance was 6.4% (teaching hospital: 7.4%; public hospital: 6.2%; private hospital: 1.4%). Nurses (8.4%) had the highest rates of compliance. Poor hand hygiene compliance in Isfahan hospitals necessitates urgent interventions to improve both hospital infrastructure and staff knowledge.

This study aims to evaluate the effect of the protocol for the preparation of oxygen-moisturizing chamber on the count of its bacteria.This study is a double- group clinical trial before and after intervention, which was carried out in the neurology ward of an educational hospital in Esfahan from July to December 2015. In this study, 64 oxygen humidifying chambers were studied in terms of number and type of microorganisms in two groups of 32 during three phases, before, immediately after, and 6 hours after its intervention. In order to identify the microorganisms, the samples were cultured on the blood agar and EMB (Eosin Methylene Blue). Then, the routine laboratory methods were used to identify the types of microorganisms. Data were analyzed using SPSS 18, Wilcoxon, Mann-Whitney, chi-square and Friedman statistical tests.The results showed that before intervention, 71.9% (46/64) of oxygen-moisturizing chambers were contaminated with microorganisms. The extent of microbial contamination was from 0 to 105 CFU. Most of the contamination was with microorganisms such as Lactobacillus spp 23.4% (15/64), Bacillus sp17.2% (11/64), Pseudomonas aeruginosa 10.9% (7/64), Coagulase-negative staphylococci 7.8% (5/64), Acinetobacter baumannii 3.1% (2/64), Sphingomonas spp 3.1%(2/64), Escherichia coli 1.6% (1/64), Streptococcus spp 3.1% (2/64), Fungus spp 3.1% (2/64). However, immediately after the intervention and 6 hours after connecting oxygen-moisturizing chamber to the patient, the infection rate was substantially reduced and reached zero (pWith regard to the fact that the contamination of oxygen-moisturizing chamber was significantly reduced after the implementation of care protocol, the implementation of this Protocol can be one of the effective measures in reducing the transmission of nosocomial infections.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of infections. The changing epidemiology of MRSA became evident in the 1990s when CA-MRSA cases were first reported. Nasal carriage of CA-MRSA is associated with an increased risk for development of infections in various populations. Materials and Methods: Anterior nares culture for the presence of methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA was taken from 345 children attending kindergartens, who didn't have any known risk factor for MRSA colonization. Also, children demographic variables were recorded. Identification of SA and community-acquired methicillin-resistant Staphylococcus aureus ( CA-MRSA) with standard microbiological test was performed. Finally, the susceptibility of isolated to various antibiotics determined. The data were analyzed with Whonet 5.6 software. Results: Of 345 children, 20 children (5.8%) were colonized with CA-MRSA, 86 children (24.9%) with MSSA and 239 cases (69.3%) didn't have SA colonization. The highest rate of MSSA and MRSA colonization was obtained at the age of 6 years. The frequency distribution of SA (MSSA and MRSA) colonization prevalence didn't have any significant differences based on age, gender and the admission time (P > 0.05); but it was significantly different in the urban areas (P < 0.001). The lowest resistance rate of CA-MRSA isolates, with a frequency of 10%, was detected with gentamicin, rifampin, and trimethoprim-sulfamethoxazole. Conclusions: In summary, CA-MRSA colonization was observed in child care centers remarkably. Therefore, by facing various infections due to SA especially in areas of low socio-economic status, it must be considered. Based on antibiogram test, empirical treatment with rifampin, gentamicin and ciprofloxacin is recommended during CA-MRSA infections.

Evolving resistant uropathogens are associated with elevated risk of morbidity and mortality both in nosocomial and in spinal cord injury (SCI)-associated urinary tract infections (UTIs). Clinico-epidemiological studies are therefore essential to facilitate empirical therapy and decrease treatment time.This study was performed at Al-Zahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. All E. coli-infected UTI hospitalized patients, except those with symptoms of UTI prior to admission or in the first 48 hours of hospitalization, were included in this study as group A. All E. coli-infected SCI-associated UTIs were included in group B. Urine samples were cultured and the MICs of nine antibiotics on the isolated bacteria were determined by the gradient concentration method with E. coli ATCC25922 as the standard control.Antibiotic-resistant uropathogens were more prevalent among the nosocomial than the SCI-associated UTIs. The antibiotic-resistance rates of isolated E. coli in the nosocomial and SCI-associated UTIs were 13.9% and 5.9% for amikacin, 65% and 40.5% for ceftazidime, 69.8% and 32.4% for ceftriaxone, 50% and 41.2% for ciprofloxacin, 56.9% and 13.6% for gentamicine, 2.1% and 0% for imipenem, 3.9% and 0% for meropenem, and 73.6% and 63.6% for trimethoprim/sulfamethoxazole, respectively. Only resistance to nalidixic acid was mildly higher in SCI E. coli. The MIC50 of all the antibiotics except nalidixic acid was higher in nosocomial E. coli.Despite more risk factors for antibiotic-resistant E. coli in SCI patients, antibiotic-resistant E. coli was observed more in nosocomial UTIs, which may be attributable to the hospital environment.

The aim of this study is to identify the antibiotic sensitivity pattern of pathogens involved in the process of surgical site infection, in surgical wards. Changes made in the pattern of antibiotic use will result in different microorganism susceptibility patterns, which needs correct determination for precise empiric antibiotic therapy. One thousand patients (62% men and 38% women, 18- 74-years-old, with mean age 43 +/- 8)) who underwent surgical treatment, in Alzahra University Hospital, Isfahan University of Medicine, Isfahan, Iran, were studied from 2005 to 2006. Surgical wound infections, based on the reported criteria, were aspirated for culturing within 1 plus gram staining of prepared smears. Minimum Inhibitory Concentrations (MICs) were determined for samples and all derived data were compared by SPSS 13 and WHO net 5 software. The prevalence of SSI was 13.3% with 150 positive cultures, totally. Of 150 bacteria, isolated from surgical site infections Staphylococcus aureus had most frequency (43%). Resistance of isolated organisms was 41.7% in amikacin, 65 and 78.6% in ceftazidime, 85.7% in ceftriaxone, 61.5% in ciprofloxacin, 78.8% in gentamicine, 6.4% in imipenem, 13% in meropenem and 70.6% in trimethoprim/sulfamethoxazole, respectively. 78.9% of Staphylococcus aureus isolates were MRSA and vancomycine was the most effective antibiotic without any resistance. Among 10 isolates of coagulase negative Staphylococcus, no vancomycine resistance was seen, but in contrast all cases were resistant to oxacillin. The most common gram negative organism was Klebsiella (18 isolates) in which 100 and 80% were sensitive to imipenem and meropenem, respectively. Seventeen cases were E. coli, in which the most sensitivity was to meropenem (80%) and imipenem (77.8%). Thirteen cases of Pseudomonas were detected, in which 16.7% were resistant to imipenem and 8.3% to meropenem. Our results demonstrated that the total antibiotic resistance is increasing among SSIs, with an up sloping pattern, which will contact with a constant empiric antibiotic therapy. So, precise up to date antibiogram tantalize us toward balancing the rate of total antibiotic resistance to SSIs.

Injury resulting from contaminated sharp devices among health care workers (HCWs) is one of the most important concerns in medical centers. This can lead to dangerous infections such as human immunodeficiency virus, hepatitis B virus and hepatitis C virus among such people. The documentation of needle stick injuries started in Sadi Hospital, Isfahan, Iran in 2003, and our objective was to study cases of injuries by sharp devices before and after the implementation of intervention methods.In an intervention survey of the type of before and after study, we studied injuries by needle and other sharp devices among 87 HCWs in Sadi Hospital, a private hospital in Isfahan, Iran, during the years 2003-2004. The groups under study were workers and paramedical staff; and the wards under study included surgery, internal, lab, x-ray and laundry. We entered and evaluated the data in SPSS software.In the first phase of the study in 2003, 55.2% of those injured had been injured by sharp devices. After intervention in 2004, this percentage was reduced to 19.5% (p0.05). At the beginning of the study, 26.4% of the injured had been injured by sharp devices more than twice, and at the end of the study this number was reduced to 2.3% (p0.05). Also, injuries resulting from recapping were 45.8% at the beginning of the study, which was reduced to 5.9% at the end (p0.05).With regard to this study and other studies carried out in other countries, a large number of injuries by contaminated sharp devices can be prevented by implementing suitable educational programs regarding disposal of sharp devices, and by using safe needle devices.

Background/purpose The narrow spectrum of action of most bacteriocins is an important limitation for their application as antimicrobial agents. The current study describes a novel bacteriocin-like inhibitory substance (BLIS) that display extended spectrum antimicrobial activity against vancomycin-resistant Enterococcus (VRE) strains. Methods Acquired resistance profiles of Enterococcus isolates determined based on the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC) definition as multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug resistant (PDR). BLIS activity of Enterococcus isolates was investigated against Enterococcus faecalis ( E. faecalis ) ATCC 29212 as the indicator strain and clinical isolates including VRE, methicillin resistant Staphylococcus aureus (MRSA) and Gram-negative bacteria containing Pseudomonas aeruginosa ( P. aeruginosa ), Klebsiella , Acinetobacter , and Escherichia coli ( E. coli ). Results Among 273 Enterococcus isolates, 27 and 2 VRE isolates, respectively, were XDR and PDR and eight isolates had BLIS activity against the indicator strain. One of these isolates, identified as E. faecium strain DSH20 based on its phenotypical and biochemical properties, as well as its 16S rRNA gene sequence, had potent BLIS production against all 29 VRE strains, but had no activity against MRSA, P. aeruginosa , Klebsiella , Acinetobacter , and E. coli strains. It was heat stable up to 121°C for 15 minutes (autoclave condition), active within the pH range of 3–9 and had UV stability, but its activity disappeared by treatment with proteinase K, pepsin, and trypsin, demonstrating its proteinaceous nature. It was designated as an approximately 35kDa peptide using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method. Conclusion This peptide is a potential agent for use as an alternative antibacterial agent for the treatment of drug-resistant strains of VRE infection.