sina mobasheri zadeh

In developing countries, the presence and diversity of Staphylococcus species in foodstuffs have not been comprehensively studied. So, the present study aimed to investigate the dissemination of Staphylococcus spp. and their antimicrobial susceptibility pattern isolated from foodstuffs in Isfahan in 2015-2016. A total of 194 foodstuff samples were collected from different parts of Isfahan city and processed for the presence of Staphylococcus spp. The conventional tests were used for the primary detection of bacteria and the sequence analysis of 16S rRNA was used for the species identification. The antimicrobial susceptibility pattern of isolates was determined by the disk diffusion method. From a total of 194 food samples, 92 Gram-positive cocci (47.5%) were isolated. Of them, 84 isolates were Staphylococcus spp., 7 Macrococcus spp and one Micrococcus spp. The most prevalent species were S. aureus 25% (21/84), S. vitulinus 15.5% (13/84) and S. succinus sub casei 11.9% (10/84). The most antibiotic resistance rates were against penicillin (59/5%) and tetracycline (20.2%) while the lowest antibiotic resistance rates were observed for levofloxacin, rifampicin, gentamicin, and ciprofloxacin. Characterization of Staphylococcus species is important for epidemiological investigations. Proper identification and management practices including analysis of 16S rRNA for the species identification should be considered to increase food safety and prevent extra treatment costs.

Antibiotic resistance against uro-pathogens is a worldwide health concern. The aim of this study was to determine the causative bacteria and antibiotic susceptibility patterns among hospitalized patients with community acquired urinary tract infection (UTI).

This cross-sectional study was performed in 2016-2018 in Isfahan, Iran. Urine samples were examined for strain identification and antimicrobial resistance pattern using standard tests. Stratification was done based on gender and age (<20 and >20 years) groups. Chi-square and Fisher exact tests were applied to assess differences in etiology and susceptibility rates between groups.

Among 1180 patients, Escherichia coli was the commonest pathogen (68.1%) followed by Enterococcus spp. (8.8%) and Klebsiella pneumonia (8.0 %). Non-E. coli pathogens were more frequent among males (41.8% versus 24.8% in females, P<0.01) and in those aged under 20 years (61.0% versus 22.2% in older than 20 years, P<0.01). Isolated bacteria revealed high susceptibility to imipenem (94.9%), meropenem (92.2%), and amikacin (91.9%); moderate sensitivity to gentamicin (64.4%), cefepime (52.6%) and ceftazidime (47.2%); and low susceptibility to ceftriaxone (41.8%), cefotaxime (40.0%), ciprofloxacin (38.6%) and trimethoprim-sulfamethoxazol (31.3%). The sensitivity of isolates to ceftriaxone, ceftazidime, cefepime, imipenem, meropenem, amikacin and ciprofloxacin was significantly higher in females. Compared to the older age group, uro-pathogens were more susceptible to ciprofloxacin, ceftazidime and gentamicin in patients aged under 20 years.

We found that imipenem, meropenem and amikacin were good choices for empiric therapy of complicated or severe hospitalized patients with community acquired UTI; and gentamicin, cefepime and ceftazidime were acceptable as initial choices in non-severe infections in the area.

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.

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.

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.

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.

Staphylococcus aureus (S. aureus) is one of the most important pathogens in burn infections colonized in the nose and increase the risk of infections.

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.

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.

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.

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.

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.

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.

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.

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.
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.
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).
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.

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).

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.

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).

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.

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.

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.

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.

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.

Macrolide, lincosamide and streptogramin B (MLSB) 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.
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.
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 MLSB (cMLSB), inducible MLSB (iMLSB), macrolide-streptogramin B-resistant (MSB) and lincosamide-streptogramin-A resistance (LSA) 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窹苺欫, in S. aureus isolates was 7% and it was only detected in MRSA isolates.
In the current study, cMLSB 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.

This study was to evaluate the prevalence of CTX-Mand TEM type ESBLs-producing K. pneumoniae and determination of MDR, XDR, and PDR phenotypes of these isolates as well as find out the genetic relationship and molecular typing of these isolates using phenotypic and genotypic methods.
Non-repetitive 96 K. pneumonia isolates were isolated from hospitalized patients in Al-Zahra hospital of Isfahan, Iran. The antibiotic susceptibility test was assessed for 20 antibiotics using Kirby-Bauer disk diffusion method. The frequency of ESBL-producing isolates was determined by phenotypic confirmatory test. All ESBLs-producing isolates were assessed for blaTEM and blaCTX-M genes using PCR method. Molecular typing was performed by enterobacterial repetitive intergenic consensus sequence-based PCR (ERIC-PCR).
Among 96 isolates, 58 isolates (60.4%) were ESBL-producers. In this study, 85.7% and 30.3% of ESBL-producing isolates showed MDR and XDR phenotypes, respectively. No PDR isolate was found. PCR amplification on ESBL-producing isolates showed that 47 (81%) isolates were carried blaTEM gene, while blaCTX-M was detected in all isolates (100%). ERIC-PCR typing was characterized the high genetic similarity among ESBL-producing K. pneumonia isolates and revealed 32 band pattern for the isolates.
This study showed high prevalence of important ESBL genes (blaCTX-M and blaTEM genes) among the K. pneumoniae isolated from in-patients. Constant following of ESBLs, also identification of their types, in bacteria isolated from hospitalized patients has an important clinical impact. It can provide valuable information for the choice of appropriate antibacterial therapy and decrease of antibiotic resistance.

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.

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.

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.

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

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.

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.

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.

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.

Extended-spectrum beta-lactamase of CTX-M-type is considered as an important mechanism resistant to beta-lactam drugs in the gram-negative pathogens. In this study, the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) as well as the frequency of CTX-M genes from urinary tract infections in inpatients and outpatients caused by Escherichia coli in selected health centers in Isfahan, Iran, was studied in 2013. The study was carried out on 120 E. coli isolates from inpatients and outpatients with urinary tract infection. The susceptibility of isolates was tested using disc diffusion method. The ESBL-producer strains were confirmed using combined discs method. Finally, the blaCTX-M gene was determined in ESBL-producer isolates using polymerase chain reaction (PCR) method. To identify the strains of E. coli producing CTX-M genes, PCR method was used. The collected data were entered and analyzed in WHONET 5.6 and Excel softwares. From 120 strains of E. coli, 12 outpatient (20.0%) and 33 inpatient (55.0%) isolates were ESBL-producer. 84.4% and 60.1% of outpatient isolates and 94.9% and 84.8% of inpatient isolates showed resistance to ampicillin and co-trimoxazole, respectively. PCR analysis revealed that 30 isolates had CTX-M gene. The production of ESBL, in particular in isolates of inpatients, is a big threat for use of the broad-spectrum cephalosporins. Given the presence of CTX-M gene in the high proportion of the isolates, more molecular and epidemiological studies on pathogenic bacteria in health centers is required to be able to have a common plan to control bacterial resistance.

The antibiotic resistant of In Enterobacteriaceae bacteria family to carbapenem drugs is continuously increasing. The aims of this study were to determine the prevalence of carbapenems resistance in multidrug-resistant (MDR) strains of E. coli and Enterobacter and to determine their standard antibiotic resistance patterns and frequency of Klebsiella pneumoniae carbapenemase (KPC) enzyme in Isfahan.

This cross-sectional study, was carried out on 300 clinical samples collected from three hospitals in Isfahan. Antibiotic susceptibility of bacteria was determined by disk diffusion method. In carbapenem resistant strains, the minimum inhibitory concentration (MIC) of imipenem and meropenem were calculated by E-test. The resistance rate to 31 antibiotics belonging to 17 classes were evaluated. The frequency of MDR, extended drug resistance (EDR) and pan drug resistant (PDR) strains were determined. The prevalence of the KPC enzyme in these strains was determined by phenotype method.

Totally, 191 strains of E. coli and 43 Enterobacter strains were isolated, among them 151 (79%) and 35 (81%) were MDR respectively. In both bacteria, effective antibiotics were carbapenem, piperacillin/tazobactam, amikacin, cefepime and nitrofurantoin. Five strains of E. coli (3.3%) and three strains of Enterobacter (6.8%) were resistant to carbapenems and the MIC results confirmed these results. Overall 7 strains out of these 8 strains were MDR and only one strain of E. coli was XDR. No PDR strain was detected. KPC enzymes in four E. coli strains (6.2%) and two strains  (7.5%) belonged to Enterobacter strains.

This study demonstrated the high prevalence of MDR among hospitalized patients in Isfahan. This results shows the emergent changes in the level of antibiotic utilization in hospitals.

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.. This study was conducted to characterize ESBLs among E. coli and K. pneumonia isolates by molecular and phenotypic 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.. 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%).. 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..

The aim of this ex vivo study was to compare the antimicrobial effect of triantibiotic paste, 0.2% chlorhexidine gel, Propolis and Aloe vera on Enterococcus faecalis in deep dentin. Ninety fresh extracted single-rooted teeth were used in a dentin block model. Seventy-fi ve teeth were infected with E. faecalis and divided into four experimental groups (n = 15). Experimental groups were treated with triantibiotic mixture with distilled water, 0.2% chlorhexidine gel, 70% ethanol + Propolis and Aloe vera. Fifteen teeth treated with distilled water as the positive control and 15 samples, free of bacterial contamination, were considered as the negative control. Gates- Glidden drill #4 was used for removal of surface dentin and Gates-Glidden drill #5 was used to collect samples of deep dentin. The samples were prepared and colony-forming units were counted. Data were analyzed by one-way ANOVA and post hoc Tukey tests. Statistical signifi cance was defi ned at P < 0.05. Triantibiotic mixture group exhibited the least bacterial growth. However, the rate of bacterial growth showed no signifi cant differences between chlorhexidine and Propolis groups (P > 0.05). Aloe vera had antibacterial effects on E. faecalis, but in comparison with other medicaments, it was less effective (P < 0.05). This experimental study showed that triantibiotic mixture, 0.2% chlorhexidine gel, Propolis and Aleo vera were relatively effective against E. faecalis. All the intracanal medicements had similar effects on E. faecalis in deep dentin except for Aloe vera.

Production of β-lactamase enzymes is the most common and important mechanism of resistance in Gram-negative bacteria. Th e objective of this study was to assess frequency of three main β-lactamase enzymes, including extended spectrum β-lactamases (ESBLs), metallo-β-lactamase (MBL), and Klebsiella pneumoniae carbapenemase (KPC) enzymes in Escherichia coli and Klebsiella spp. isolated from nosocomial and community urinary tract infections (UTI).

In a cross-sectional study from March to December 2012, midstream urine samples were obtained from patients suspicious of UTI who were hospitalized or referred to Al-Zahra Hospital, Isfahan, Iran. Samples were cultured and E. coli and Klebsiella spp. were isolated. Prevalence of ESBLs, KPC, and MBLs producing E. coli and Klebsiella spp. were studied by double-disk (combined-disk), the modifi ed Hodge test and imipenem-ethylenediaminetetraacetic acid combined disc methods respectively. In addition, their antimicrobial susceptibility patterns determined and resistant to carbapenem drugs confi rmed by minimum inhibitory concentrations based on E-test method.

A total of 1080 E. coli and 484 Klebsiella strains were isolated during study period. Among 720 E. coli and 384 Klebsiella isolates from hospitalized patients, 300 (41.7%) and 198 (51.5%) were ESBLs producers, respectively. In out-patients samples, the rate of ESBLs production was 25% (90/360) and 40% (40/100) in E. coli and Klebsiella isolates, respectively. Prevalence of MBLs producing in hospital E. coli and Klebsiella isolates were 0.3% (2/720) and 2.6% (10/384), and for KPC data were 1.4% (10/720) and 48.4% (186/384), respectively. No MBLs and KPC producing isolate was seen in non-hospital E. coli and Klebsiella isolates except for one non-hospital KPC producing Klebsiella isolate.

Th e result of our study showed high prevalence of ESBLs and KPC, but low prevalence of MBLs in cultured bacteria from urine samples of patients with acute UTI. In addition, KPC was the main carbapenem resistance mechanism in Klebsiella and E. coli isolates.

The aim of this study was to isolate and identify KPC (Klebsiella pneumonia carbapenemase) enzyme producing strains of Enterobacteriaceae، and determine their antibiotic susceptibility pattern in three hospitals of Isfahan، Iran. This subject has not previously been investigated comprehensively. KPC detection was done by Modified Hodge Test (MHT) and their antibiotic susceptibility patterns were determined by disc diffusion method. The total of 475 strains were isolated and detected as Enterobacteriaceae during the period of 9 months (July 2012-March 2013) in three hospitals in Isfahan province، Iran. These isolates contained Escherichia coli: 285 strains (60%)، Klebsiella: 128 strains (27%)، Enterobacter aerogenes: 16 strains (3. 4%)، Enterobacter cloacae: 9 strains (1. 9%)، Proteus vulgaris: 12 strains (2. 5%)، Proteus mirabilis: 4 strains (0. 84%)، Citrobacter freundii: 8 strains (1. 7%)، Citrobacter diversus: 3 strains (0. 6%)، Serratia marcescens: 3 strains (0. 6%)، Shigella sonnei: 4 strains (0. 84%)، Salmonella paratyphi A: 2 strains (0. 42%)، and Providencia stuartii: 1 strain (0. 2%). Percentage resistant to ceftazidime and cefotaxime and non-susceptibility to imipenem and meropenem for above isolates were، respectively، as follows: for Escherichia coli isolates 60، 63، 6، and 9; for Klebsiella isolates 70، 75، 55، and 58; for Klebsiella pneumoniae 100، 100، 95، and 94; and for other Enterobacteriaceae isolates 20، 17، 5، and 3. Our results showed that KPC test was positive for 2 isolates (0. 7%) among Escherichia coli strains، 65 (87%) isolates among Klebsiella pneumoniae، and 1 isolate (6%) among Proteus strains. This was approved by Etest based MIC method. In general، our results showed that among Enterobacteriaceae isolates، Klebsiella pneumoniae isolates had higher KPC enzyme production، and most strains had multidrug resistant.

Furthermore application of bacteriocins as alternates for antibiotics، they are fermented as food preservation currently. The aim of this study was isolation and purification of ultraviolet-resistant bacteriocins from enterococci strains active against Listeria monocytogenes. Different strains of enterococci bacteria were isolated and identified from various clinical specimens and bacteriocin production were evaluated against strains of Listeria monocytogenes. An isolate of enterococcus bacteria that produce significant bacteriocin against all studied strains of Listeria monocytogenes was identified based on its phenotypical and biochemical properties as well as its 16SrRNA gene sequencing. In the next stage، this bacteriocin was purified and the effects of proteolytic enzymes، pH، temperature and ultraviolet radiation (UV) on its activity were tested and its molecular weight was determined by SDS-PAGE (Sodium dodecyl sulfate polyacrylamide gel electrophoresis) method. 17 strains of enterococci were isolated and five isolates exhibited an inhibitory effect against Listeria monocytogenes strains and among them، one enterococcus had inhibitory effect against all four strains of Listeria monocytogenes. This enterococcus was identified as Enterococcus faecium strain DSH20 (access number: JX567733. 1). Using proteolytic enzymes led to the loss of antimicrobial activity; so، protein nature of it was confirmed. Bacteriocin production was resistant to UV، high temperature and pH changes. The molecular weight of the bacteriocin was at approximately 35 kilodaltons. Biochemical properties of this bacteriocin، such as thermal stability، resistance to UV radiation and pH، were significant. These properties present it as an alternative of antimicrobial agents against Listeria monocytogenes and preserving of fermented foods.

Patients under hemodialysis are exposed to remarkable volume of water. As dialysis water is in direct contact with patients’ blood, absence of regular disinfection of pipes will facilitate the transfer of the endotoxins produced by bacteria in water to the patient's body. Thus, regular control of dialysis system and water disinfectant equipment is compulsory. This study aimed at comparing relative frequency of positive culture for microorganisms in piped water before and after filtration, culture of water after passing from pipes, and culture of dialysis fluid before entering the dialysis filter in hemodialysis section of Alzahra Medical Center (Isfahan, Iran). During 2010 and 2012, an interventional study was performed in Alzahra Hospital. Samples were taken from piped water before and after filtration and from dialysis fluid before passing from membrane. The obtained samples were cultured in tryptic soy agar (TSA) and the isolated bacteria were then evaluated. Interventions included the disinfection of pipes used for transmission of water and replacement of pipes in hemodialysis section. Purified water was studied before and after passing the pipes. Dialysis fluid was also assessed before and after the intervention. Bacteria had grown in eight out of 14 samples (57%) before the intervention. In fact, five samples developed Escherichia coli, three had pseudomonas, and one had candida. However, after the intervention, only one out of 14 samples was found to have bacteria (alcaligenes) after filtration and before entering dialysis water pipes. According to the results of this study, the probability of bacterial growth is very high in filtration system of dialysis water. Regular disinfection and microbial sampling and culture are hence crucial.

Colonization of bacteria on the equipments in touch with airway and respiratory mucosa may cause respiratory infections. According to available protocols، endotracheal tube connectors should be disposable، but because of financial issues many hospitals use it more than once. In the present study، the colonization rate of endotracheal tube connectors after 24، 48 and 72 hours of administration in multiple patients on mechanical ventilation in the operating room was assessed. In this study، 150 endotracheal tube connectors after repeated use in different patients have been sampled and cultured using standard microbiological methods. Samples were categorized in three groups based on the duration of administration (24، 48 or 72 hours). Colony counts were identified and compared among the three groups. Colonization rate after 24، 48 and 72 hours of usage was 2%، 18% and 30%، respectively (p<0. 05). Separated bacteria usually were in kinds of Streptococci، Bacillus SP، Coagulate negative staphylococci، Klebsiella SP and Mold. Using endotracheal tube connector for more than 24 hours significantly increases the colonization rate. In hospitals with limited financial resources، repeated use of endotracheal tube connector up to twenty four hours maybe acceptable.

The present study was conducted to evaluate the relative frequency of Clostridium difficile (C. difficile) in patients at a university hospital, Isfahan, Iran. This descriptive, analytic study was conducted on 162 patients hospitalized in various wards of Alzahra Hospital (an 800-bed teaching hospital) of Isfahan during October 2009 to March 2010. Fecal samples of patients who suffered from diarrhea after receiving antibiotics were collected. Microbial analysis was performed to determine the existence of C. difficile. C. difficile toxins (A and B) were detected by ELISA method. The obtained data was statistically analyzed using chi-square test in SPSS at a significance level of P < 0.05. C. difficile toxins were detected in 36 (22.2%) patients. The frequency of toxins occurrence was significantly higher in men (P ≤ 0.005). In addition, a large number of individuals infected by C. difficile toxins were children under 4 years of age. Ceftriaxone caused many cases of diarrhea in our studied population. In general, based on our results, wrong prescription and antibiotics abuse can cause infection with C. difficile in patients receiving antibiotics. Therefore, the physicians must pay more attention to the recovery of patients with antibiotics.

Intravenous drug users (IVDUs) are the most at risk group for viral hepatitis C and injection drug is responsible to more than 60% of HCV infected new cases worldwide. Hepatitis C screening in centers for methadone maintenance treatment (MMT) has several benefits in harm reduction stategies.

In an action research study, after coordinating centers for MMT, questiononaires including demographic and risk factors of HCV were sent to 80 active centes in Isfahan province to complete and add their result for HCV-Ab test.

Only seven centers with 1055 members, sent their completed questionaires to administrators, but most of documents were without any HCV-Ab test results. Overall, 74 (7.0%) participants were positive for hepatitis C.

The results of this study indicated serious problem in execution which was due to lack of cooperration of the center's mannagers, stuffs and members. Hence, it is recommended to do active intervention and consider a reward for future investigators.

Introduction and Escherichia coli and Klebsiella pneumoniae are the most agent of urinary tract infection (UTI) and prevalence Extended-Spectrum Beta-lactamase (ESBLs) in these bacteria due to spread of antibiotic resistance and mortality and morbidity in patients. The best manner for control of ESBLs in bacteria, are inhibition of spread these bacteria and use of standard method for recognizes ESBLs producer strains.Subject of this study was comparison frequency of ESBLs in Escherichia coli and Klebsiella pneumonia strain in UTI acquired patients with phenotypic test. This cross-sectional search was performed in Azzahra and Shariaty hospitals during of 2008-2009 years in Esfahan, according to statistical formula randomly selected 91 samples from urinary infections. Bacterial identification was performed with microbiological methods, ESBLs production was performed with screening and confirmatory test and survey antibiotics resistant pattern was performed with Kirby method. Frequence of ESBLs in E.coli and K.pneumoniae strains was respectively 47.97% and 41.66%. According to antibiogram result respectively 59.2%, 54.9%, 30.3%, 27.8%, 19.5% and 16.7% of E.coli strains were resistant into Co-Trimoxazole, Nalidixic acid, Ciprofloxacin, Gentamicin, Ceftazidime and Nitrofurantoin and respectively 75%, 50%, 40%, 44.5%,37.5%, 37.5%, 22.3% and 0% of K.pneumoniae strains were resistant into Ampicillin, Co-Trimoxazole, Nitrofurantoin, Ceftazidime, Amikacin, Cephotaxime, Imipenem and Ciprofloxacin. The result showed high frequence of ESBLs, so antibiotic resistant in isolated bacteria from hospitalized into out patience's that represent high spread antibiotic resistant strains in hospitals.

The rapid emergence of antibiotic resistance, especially broad-spectrum antibiotics, resulted in the avid use of new potent antibiotics. Ceftriaxone and ceftazidime, two third-generation cephalosporin, are usually used to manage complicated and uncomplicated infections. The use of cefepime in resistant infections is increasing gradually, which put this potent antibiotic at risk of resistance.Patients and During an 18-month period, a total of 220 gram-negative bacteria including Pseudomonas spp, Serratia spp, Acinetobacter spp, Proteus spp, E-coli and Klebsiella spp. have been isolated by standard microbiologicalmethods from nosocomial surgical site, abscess, blood stream and urinary tract infections. MIC of antibiotics on isolated bacteria was determined by gradient concentration method. Totally, 29.4%, 19.5% and 23.3% of isolated bacteria with MIC≤8μg/ml were sensitive to cefepime, ceftriaxone and ceftazidime, respectively. High level resistance with MIC≥256μg/ml to cefepime, ceftriaxone and ceftazidime was also observed in 47.1%, 70.8% and 62.5% of cases, respectively (p<0.05). High level resistance to cefepime were more commonly observed for pseudomonas (73.1%) and Klebsiella spp. (73.5%), respectively (p<0.05). According to CLSI criteria, 47.1% of isolated bacteria in this study showed high level of resistance(MIC≥256μg/ml) to cefepime. Therefore application of cefepime, as a drug of choice, for gram-negative organisms is not reasonable. Our result demonstrated that this potent antibiotic should not be used as a choice for empiric antibiotic therapy, in the cases of nosocomial infections caused by gram-negative organisms.