Genotyping of ESBL Producing Uropathogenic Escherichia coli in West of Iran

Antibiofilm activity of promethazine against ESBL-producing strains of Escherichia coli in urinary catheters

The bacterium Escherichia coli is one of the main causes of urinary tract infections. The formation of bacterial biofilms, especially associated with the use of urinary catheters, contributes to the establishment of recurrent infections and the development of resistance to treatment. Strains of E. coli that produce extended-spectrum beta-lactamases (ESBL) have a greater ability to form biofilms. In addition, there is a lack of drugs available in the market with antibiofilm activity. Promethazine (PMZ) is an antihistamine known to have antimicrobial activity against different pathogens, including in the form of biofilms, but there are still few studies of its activity against ESBL E. coli biofilms. The aim of this study was to evaluate the antimicrobial activity of PMZ against ESBL E. coli biofilms, as well as to assess the application of this drug as a biofilm prevention agent in urinary catheters. To this end, the minimum inhibitory concentration and minimum bactericidal concentration of PMZ in ESBL E. coli strains were determined using the broth microdilution assay and tolerance level measurement. The activity of PMZ against the cell viability of the in vitro biofilm formation of ESBL E. coli was analyzed by the MTT colorimetric assay and its ability to prevent biofilm formation when impregnated in a urinary catheter was investigated by counting colony-forming units (CFU) and confirmed by scanning electron microscopy (SEM). PMZ showed bactericidal activity and significantly reduced (p < 0.05) the viability of the biofilm being formed by ESBL E. coli at concentrations of 256 and 512 μg/ml, as well as preventing the formation of biofilm on urinary catheters at concentrations starting at 512 μg/ml by reducing the number of CFUs, as also observed by SEM. Thus, PMZ is a promising candidate to prevent the formation of ESBL E. coli biofilms on abiotic surfaces.

High prevalence of plasmid-mediated quinolone resistance in escherichia coli strains producing extended-spectrum beta-lactamases isolated from faeces and urine of pregnant women with acute cystitis

BACKGROUND

Escherichia coli is the most common etiological agent of urinary tract infections (UTIs). Meanwhile, plasmid-mediated quinolone resistance (PMQR) is reported in E. coli isolates producing extended-spectrum β-lactamases (ESBLs). Furthermore, the reservoirs and mechanisms of acquisition of uropathogenic Escherichia coli (UPEC) strains are poorly understood. On the other hand, UTIs are common in pregnant women and the treatment challenge is alarming.

METHODS AND RESULTS

In the present study, 54 pregnant women with acute cystitis were included. A total of 108 E. coli isolates, 54 isolates from UTI and 54 isolates from faeces of pregnant women (same host) were collected. In the antimicrobial susceptibility test, the highest rate of antibiotic resistance was to nalidixic acid (77%, 83/108) and the lowest rate was to imipenem (9%, 10/108). Among the isolates, 44% (48/108) were ESBLs producers. A high frequency of PMQR genes was observed in the isolates. The frequency of PMQR genes qnrS, qnrB, aac(6')-Ib-cr, and qnrA was 58% (63/108), 21% (23/108), 9% (10/108), and 4% (4/108), respectively. Meanwhile, PMQR genes were not detected in 24% (20/85) of isolates resistant to nalidixic acid and/or fluoroquinolone, indicating that other mechanisms, i.e. chromosomal mutations, are involved in resistance to quinolones, which were not detected in the present study. In ESBL-producing isolates, the frequency of PMQR genes was higher than that of non-ESBL-producing isolates (81% vs. 53%). Meanwhile, UTI and faeces isolates mainly belonged to phylogenetic group B2 (36/54, 67% and 25/54, 46%, respectively) compared to other phylogenetic groups. In addition, virulence factors and multidrug-resistant (MDR) were mainly associated with phylogenetic group B2. However, predominant clones in faeces were not found in UTIs. Rep-PCR revealed the presence of 85 clones in patients. Among the clones, 40 clones were detected only in faeces (faeces-only), 35 clones only in UTI (UTI-only) and 10 clones in both faeces and UTI (faeces-UTI). We found that out of 10 faeces-UTI clones, 5 clones were present in the host's faeces flora.

CONCLUSION

This study revealed a high rate of resistance to the quinolone nalidixic acid and a widespread distribution of PMQR genes in MDR E. coli strains producing ESBLs. The strains represented virulence factors and phylogenetic group B2 are closely associated with abundance in UTI and faeces. However, the predominant clones in faeces were not found in UTIs and it is possible that rep-PCR is not sufficiently discriminating clones.

Study of antibiotic resistance and virulence genes in Escherichia coli isolated from urinary tract infection patients in Tanta University Hospitals

This study aimed to investigate the prevalence of antibiotic resistance genes CTX-M and Qnr, as well as the virulence genes HlyA, Pap, CNF1, and Afa, in uropathogenic Escherichia coli (UPEC) isolates from the Egyptian population. In this cross-sectional study, a total of 50 E. coli isolates were collected from urine samples from patients with urinary tract infections (UTIs) admitted to Tanta University Hospital from December 2020 to November 2021. The isolates were cultured, identified, and tested for antibiotic susceptibility by the disc diffusion method. The CTX-M, Qnr (QnrA, B, and S), Pap, CNF1, HlyA, and Afa genes were detected by polymerase chain reaction in UPEC isolates. The Pap, CNF1, HlyA, and Afa genes were found to be positive in 18%, 12%, 10%, and 2% of the isolates, respectively. In addition, CTX-M and QnrS were found to be positive in 44% and 8% of the isolates, while QnrA and B were not detected. Furthermore, positive Pap, CNF1, and HlyA genes were significantly associated with both upper and lower UTIs, increased frequency, urgency, and dysuria, and complicated UTIs, as well as pyuria over 100 white blood cells per high-power field. In conclusion, the prevalence of virulence and antibiotic resistance genes varies by population. At our hospital, the Pap gene is the most prevalent virulence gene and was strongly associated with complicated UTIs, while the CTX-M and QnrS genes were the most prevalent and related to antibiotic resistance. Our findings, however, should be interpreted with caution due to the small sample size.

High frequency and molecular characterization of ESBL-producing Enterobacteriaceae isolated from wound infections in North Lebanon

BACKGROUND

Extended-spectrum beta-lactamases producing Enterobacteriaceae (ESBL-PE) represent a major problem in wound infections. Here, we investigated the prevalence and molecular characterization of ESBL-PE associated with wound infections in North Lebanon.

RESEARCH DESIGN AND METHODS

A total of 103 non-duplicated E. coli and K. pneumoniae strains isolated from 103 patients with wound infections, were collected from seven hospitals in North Lebanon. ESBL-producing isolates were detected using a double-disk synergy test. In addition, multiplex polymerase chain reaction (PCR) was used for the molecular detection of ESBLs genes.

RESULTS

E. coli was the predominant bacteria (77.6%), followed by K. pneumoniae (22.3%). The overall prevalence of ESBL-PE was 49%, with a significantly higher rate among females and elderly patients. K. pneumoniae was the common MDR and ESBL-producer bacteria (86.95% and 52.17%) compared to E. coli (77.5% and 47.5%). Most of the isolated ESBL producers harbored multiple resistant genes (88%), where blaCTX-M was the most predominant gene (92%), followed by blaTEM (86%), blaSHV (64%), and blaOXA genes (28%).

CONCLUSIONS

This is the first data on the ESBL-PE prevalence associated with wound infections in Lebanon, showing the emergence of multidrug-resistant ESBL-PE, the dominance of multiple gene producers, and the widespread dissemination of blaCTX-M and blaTEM genes.

Incidence of Urinary Tract Infection Among Patients: Systematic Review and Meta-Analysis

Healthcare-associated infection is one of the most common and severe threats to patients' health and remains a significant challenge for healthcare providers. Among healthcare-associated infections, urinary tract infection (UTI) is one of the most common infections. This study aimed to determine the global incidence of UTI among patients. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline was used to perform this systematic review and meta-analysis. The articles were searched from April 4 to August 5, 2022, from electronic databases (Scopus, PubMed, Web of Science, Google Scholar, DOAJ, and MedNar) using Boolean logic operators, MeSH terms, and keywords. The quality of the study was assessed using the JBI Critical Assessment tool. One thousand nine ninety three articles were retrieved from the electronic databases, of which 38 articles conducted on 981 221 patients were included in the current study. The study found the global pooled incidence of UTI accounted for 1.6%. Based on the subgroup analysis by survey period and WHO region, the highest incidence of UTI was reported in the African Region [3.6%] and among studies conducted between 1996 and 2001 [3.7%]. This study revealed the overall pooled incidence of UTI was 1.6%. The highest incidence of UTI (3.6%) was reported in the African region. This indicates that there is a need to implement safety measures.

Clonal groups of extended-spectrum β-lactamase and biofilm producing uropathogenic Escherichia coli in Iran

Pathogenicity of a bacterium is affected by the social characteristics of the population and environmental factors. The ability of biofilm formation among β-lactamase-producing uropathogenic Escherichia coli (UPEC) could facilitate the exchange of antibiotic-resistance genes, which resulted in widespread dissemination of antibacterial drug resistance. We investigated the prevalence of biofilm and β-lactamase producing UPECs among patients with urinary tract infection (UTI) in two cities with different demographics and climates in Iran. A total of 265 E. coli was isolated from patients with UTIs from two referral hospitals (n = 191) and two outpatient clinics (n = 74) in Isfahan and Zahedan, Iran. Production of curli and cellulose, and, biofilm formation was investigated using Congo red agar and microtiter plate methods, respectively. Biofilm producing (BFP) isolates (n = 107) were further characterized using rep-PCR, antimicrobial susceptibility testing and extended-spectrum β-lactamase (ESBL)/AmpC phenotypic production. Isolates were also screened for the presence of carbapenemase, ESBL and AmpC genes using multiplex PCR.   High diversity was found among BFP strains in both cities, with 58% strains producing ESBL and 21% producing AmpC. ESBL (98%), AmpC (50%) and carbapenemase genes (40%) were identified in BFP strains with ESBL-positive phenotype, respectively. The prevalence of BFP strains, antibiotic resistance and β-lactamase genes in Zahedan, a low socioeconomic city with a warm climate, was significantly higher than that of Isfahan. High prevalence of biofilm and β-lactamase producing UPEC strains among strains from Zahedan suggests that socioeconomic status and environmental factors might have a role in pathogenicity of the strains.

Studies on Virulence and Extended-Spectrum β-Lactamase-Producing Uropathogenic Escherichia coli Isolates and Therapeutic Effect of Fosfomycin in Acute Pyelonephritis Mice

The understanding about virulence factors (VFs) and the drug resistance of uropathogenic Escherichia coli (UPEC) helps us understand the pathogenesis of urinary tract infections (UTIs) and make better decisions for clinical treatment. This study examined the correlation between the extended-spectrum β-lactamases (ESBLs) phenotype and VFs in UPEC strains. In addition, we validated the therapeutic potential of fosfomycin in acute pyelonephritis mice. From May 2017 to November 2018, 22 nonduplicate E coli. strains were isolated from UTI patients. PCR was utilized to detect the distribution of virulence genes. We also analyzed the ESBL phenotype in E coli. We further evaluated the therapeutic effect of intravenous fosfomycin treatment in the acute pyelonephritis (APN) model. All 22 UPEC strains expressed the type 1 fimbriae (FimH) gene and more than 50% (12/22) of strains produced ESBLs. The detection rates of the iron acquisition-associated genes ChuT and IutA were 77.3% (n = 17) and 50% (n = 11) and those of P fimbria papA and papC genes were 45% (n = 10) and 50% (n = 11), respectively. Though the VFs were closely related with pathologenicity, the relationship between VFs and ESBLs still needs further investigation. Furthermore, intravenous fosfomycin 800 mg/kg significantly reduced the bacterial load and the inflammatory infiltration in the bladder and kidney, maintaining the structural integrity of the kidney. Intravenous fosfomycin administration can be used for the treatment of acute pyelonephritis caused by highly pathogenic and drug-resistant UPEC strains.

Prevalence of ESBL and AmpC genes in E. coli isolates from urinary tract infections in the north of Iran

Beta-lactam resistance in Gram-negative bacteria, especially Escherichia coli, is a main clinical problem. It is often caused by the production of β-lactamases, particularly extended-spectrum β-lactamases (ESBLs) or AmpC enzymes. This study was undertaken to characterize ESBL and AmpC producers among Escherichia coli isolates from urine samples. During six months, 263 E. coli isolates were detected by standard biochemical tests. The isolates were screened for ESBL production by the double-disk synergy test using Ceftazidime (30 μg) and Cefotaxime (30 μg) disks and confirmed by combined disk diffusion test using Clavulanic acid. AmpC production was confirmed by an AmpC disk test based on filter paper disks impregnated with EDTA. The presence of genes encoding TEM, SHV, CTX-M, CIT, FOX, MOX, ACC, and EBC were detected by PCR. 263 E. coli isolates were selected for the combined disk (Ceftazidime, Cefotaxime, and Clavulanic acid) assay in the disk agar diffusion test. In the combined disk assay, among 263 isolates, 121 (46%) isolates were detected as ESBLs, and none of the isolates were AmpC producers. PCR performed on all ESBL producers and blaSHV, blaTEM, and blaCTX-M were detected in 42 (34.7%), 44 (36.4%), and 47 (38.8%) cases, respectively. Also, from 48 Isolates with zone diameters of less than or equal to 18 mm to Cefoxitin, 7 (14.6%), 4 (8.3%), and 9 (18.8%) cases contained MOX, EBC, and CIT genes, respectively. DHA, FOX, and ACC genes were not detected in any sample. Since pathogens evolve in the hospital setting, updating local data, such as this research, offers scientific evidence to improve the outcome of nosocomial infections.

Frequency of quinolone resistance genes among extended-spectrum β-lactamase (ESBL)-producing Escherichia coli strains isolated from urinary tract infections

Background

As an opportunistic pathogen, Escherichia coli (E. coli) is widely recognized as the main cause of nosocomial infections as well as some disorders especially those associated with urinary tract infections (UTIs). This study, therefore, sets out to determine the extent of antibiotic resistance to quinolones and to measure the frequency of qnr genes (A, B, and S) within extended-spectrum beta-lactamase (ESBL) and non-ESBL-producing strains of E. coli isolated from UTI-diagnosed patients as well as to investigate their antimicrobial susceptibility patterns for some selected antibiotics in southwest Iran.

Methods

Two hundred E. coli strains were isolated from UTI-diagnosed patients, hospitalized in nine different wards of Ahvaz Golestan Hospital between November 2015 and March 2016. The isolates were confirmed through well-practiced phenotypical methods. Moreover, the antimicrobial susceptibility test was successfully performed using a disk diffusion method. ESBL production among the isolates was screened by double disk synergism test (DDST), and the qnr genes were identified using a multiplex PCR.

Results

Out of the 200 samples collected, 167 isolates were confirmed to be E. coli strains. Maximum and minimum resistance were reported against nalidixic acid and chloramphenicol with 65.3% and 17.4%, respectively. Most of the isolates were resistant to all three types of quinolones studied in this research. Using multiplex PCR, the qnr genes were found in 100 (59.88%) strains (qnrA = 10, qnrB = 21, qnrS = 41, qnrB-S = 21, qnrB-A = 1, qnrA-S = 3, qnrA-B-S = 3), 58% of which was found among ESBL-producing isolates.

Conclusions

Resistance to quinolones antibiotics was highest among ESBL-producing isolates harboring, especially qnrS among other determinants of the qnr gene. There is a need for sensitive antibiotic stewardship especially in hospitals of Ahvaz, Khuzestan province. Further research is needed to ascertain the gravity of quinolones resistance in Iran and to quickly act against its spread among other nosocomial pathogens.

Relationships between Virulence Factors and Antimicrobial Resistance among Escherichia coli Isolated from Urinary Tract Infections and Commensal Isolates in Tehran, Iran

Objectives

Uropathogenic Escherichia coli (UPEC) are the major cause of urinary tract infections (UTIs). Here, we determined whether sensitivity to antibiotics was related to the prevalence of iron scavenging genes, or to biofilm and hemolysis formation.

Methods

A total of 110 UPEC and 30 E coli isolates were collected from the urine of UTI patients and feces of healthy individuals without UTI, respectively. The presence of iron receptor genes and phenotypic properties were evaluated by polymerase chain reaction and phenotypic methods, respectively. Susceptibility to routine antibiotics was evaluated using the disc diffusion method.

Results

The prevalence of iron scavenging genes ranged from 21.8% (ireA) to 84.5% (chuA) in the UPEC. Resistance to ceftazidime and cefotaxime was significantly correlated with the presence of fyuA and iutA iron genes. Biofilm production was significantly associated with the prevalence of fyuA and hma iron genes. A higher degree of antibiotic resistance was exhibited by isolates that produced biofilms than by their non-biofilm producing counterparts.

Conclusion

Our study clearly indicates that biofilm production is associated with antibiotic resistance, and that iron receptors and hemolysin production also contribute to reduced antibiotic sensitivity. These results further our understanding of the role that these virulence factors play during UPEC pathogenesis, which in turn may be valuable for the development of novel treatment strategies against UTIs.

Global research output in antimicrobial resistance among uropathogens: A bibliometric analysis (2002-2016)

OBJECTIVES

Antimicrobial resistance (AMR) among uropathogens contributes to treatment failure. Research in AMR among uropathogens is important to establish treatment options. This study assessed global research trends in AMR among uropathogens.

METHODS

SciVerse Scopus was used to retrieve relevant documents for the period 2002-2016. Only journal articles were included in the analysis. Analysis of author keywords was carried out using VOSviewer.

RESULTS

A total of 1087 journal articles were retrieved with an h-index of 50. The number of publications increased noticeably in the past decade. Analysis of subject areas of retrieved documents showed that 275 (25.3%) articles were in molecular biology/genetics/microbiology/immunology, 197 (18.1%) were in pharmacological/therapeutic approaches for treatment of urinary tract infections and 615 (56.6%) were in epidemiology/public health. Terms such as multidrug-resistant and extended-spectrum β-lactamases (ESBLs) appeared more frequently in documents published in the period 2012-2016. The mean number of authors per article was 5.3. Most active authors in this field were from Japan. The USA ranked first with 148 documents (13.6%), followed by India (97; 8.9%) and Iran (84; 7.7%). The top productive institution was Tehran University of Medical Sciences (21 publications), followed by Kobe University in Japan (20 publications). The Journal of Antimicrobial Chemotherapy ranked first with 33 publications.

CONCLUSION

Research in AMR among uropathogens showed a noticeable increase in the past decade. Reports of increasing incidence of resistance among uropathogens were published from different parts of the world. Empirical therapy should be based on updated research in AMR.

Distribution of extended-spectrum β-lactam, quinolone and carbapenem resistance genes, and genetic diversity among uropathogenic Escherichia coli isolates in Tehran, Iran

OBJECTIVES

Antimicrobial resistance among uropathogenic Escherichia coli (UPEC) is increasing. The aim of this study was to evaluate antimicrobial resistance in UPEC isolates and its correlation with virulence factors.

METHODS

A total of 120 E. coli isolates were collected from patients with urinary tract infection in Tehran, Iran. Biofilm formation and antimicrobial susceptibility were determined by phenotypic tests. The combination disk diffusion test and modified Hodge test (MHT) were performed for phenotypic detection of extended-spectrum β-lactamases (ESBLs) and carbapenemases, respectively. PCR was used for the detection of virulence genes, ESBL-encoding genes, and quinolone (qnr) and carbapenem resistance genes. Pulsed-field gel electrophoresis (PFGE) was performed to explore the genetic relatedness among isolates.

RESULTS

Most isolates exhibited biofilm formation, and different frequencies of virulence genes were observed. There was a high rate of resistance, especially multidrug resistance, to most of the antimicrobial agents tested. Phenotypically, 67.5% of the isolates produced an ESBL and were resistant to different antimicrobial classes. In total, 83.3% of the isolates harboured ESBL genes, especially bla_TEM and bla_CTX-M, and 32.5% were positive for the quinolone resistance genes qnrS and qnrB. All isolates were negative for carbapenemases by the MHT and PCR. These results indicate the association between the presence of various virulence genes and antimicrobial susceptibility. PFGE analysis showed that there was great clonal diversity among the selected isolates, with 17 isolates divided into five clusters.

CONCLUSIONS

These results indicate that the high antimicrobial resistance among UPEC isolates is alarming and requires urgent attention.

Escherichia coli in Iran: An Overview of Antibiotic Resistance: A Review Article

BACKGROUND

Escherichia coli is the most prominent cause of infectious diseases that span from the gastrointestinal tract to extra-intestinal sites such as urinary tract infection, septicaemia, and neonatal meningitis. The emergence and spread of antibiotic resistance in E. coli is an increasing public health concern across the world. Rising resistance in E. coli isolates is also observed in Iran. This review summarizes the status of antibiotic resistance of E. coli isolates in Iran from 2007 to 2016.

METHODS

The data of the prevalence of E. coli antibiotic resistance were collected from databases such as Web of Science, PubMed, Scopus, Embase, Cochrane Library, Google Scholar and Scientific Information Database.

RESULTS

Antibiotic resistance in E. coli is on the rise.

CONCLUSION

Prevalence of antibiotic resistance of E. coli varies from region to region in Iran.

EXTENDED-SPECTRUM BETA-LACTAMASE PRODUCING GRAM NEGATIVE BACTERIA IN IRAN: A REVIEW

Background:

The emergence and spread of extended spectrum β-lactamase (ESBL)-producing Gram- negative bacteria (GNB), particularly in Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa, have increased all over the world. ESBLs are characterized by their ability to hydrolyze β-lactams, early cephalosporins, oxyimino-thiazolyl cephalosporins, and monobactams, but not cephamycins or carbapenems. The rate of nosocomial infections caused by ESBL-producing GNB in Asia Pacific has increased and several studies have identified their prevalence in the region. The aim of this study is to review the prevalence of ESBL-producing GNB in the West Asia and the Middle East with a particular focus on Iran.

Materials and Methods:

The available evidence from various studies (Microbia and clinical studies, retrieved from the PubMed, and Scopus databases) regarding the ESBL producing Gram negative bacteria in Iran were evaluated.

Results:

In almost all parts of the country, high resistance has been observed, especially in the central part of Iran. Up to 89.8% Escherichia coli, 72.1% Klebsiella pneumonia, 84.2% Acinetobacter baumannii, and 83.8% Pseudomonas aeruginosa isolates are ESBL positive.

Conclusion:

The present study showed the increasing prevalence of ESBLs in different regions of Iran, which could be useful to strategic policy towards reducing reduce their prevalence.

Multidrug- and Extensively Drug-Resistant Uropathogenic Escherichia coli Clinical Strains: Phylogenetic Groups Widely Associated with Integrons Maintain High Genetic Diversity

In recent years, an increase of uropathogenic Escherichia coli (UPEC) strains with Multidrug-resistant (MDR) and Extensively Drug-resistant (XDR) profiles that complicate therapy for urinary tract infections (UTIs) has been observed and has directly impacted costs and extended hospital stays. The aim of this study was to determine MDR- and XDR-UPEC clinical strains, their virulence genes, their phylogenetic groups and to ascertain their relationship with integrons and genetic diversity. From a collection of 500 UPEC strains, 103 were selected with MDR and XDR characteristics. MDR-UPEC strains were mainly associated with phylogenetic groups D (54.87%) and B2 (39.02%) with a high percentage (≥70%) of several fimbrial genes (ecpA, fimH, csgA, and papGII), an iron uptake gene (chuA), and a toxin gene (hlyA). In addition, a moderate frequency (40–70%) of other genes (iutD, tosA, and bcsA) was observed. XDR-UPEC strains were predominantly associated with phylogenetic groups B2 (47.61%) and D (42.85%), which grouped with ≥80 virulence genes, including ecpA, fimH, csgA, papGII, iutD, and chuA. A moderate frequency (40–70%) of the tosA and hlyA genes was observed. The class 1 and 2 integrons that were identified in the MDR- and XDR-UPEC strains were associated with phylogenetic groups D, B2, and A, while the XDR-UPEC strains that were associated with phylogenetic groups B2, D, and A showed an extended-spectrum beta-lactamase (ESBL) phenotype. The modifying enzymes (aadA1, aadB, aacC, ant1, dfrA1, dfrA17, and aadA4) that were identified in the variable region of class 1 and 2 integrons from the MDR strains showed resistance to gentamycin (56.25 and 66.66%, respectively) and trimethoprim-sulfamethoxazole (84.61 and 66.66%, respectively). The MDR- and XDR-UPEC strains were distributed into seven clusters and were closely related to phylogenic groups B2 and D. The diversity analysis by PFGE showed 42.68% of clones of MDR-UPEC and no clonal association in the XDR-UPEC strains. In conclusion, phylogenetic groups including virulence genes are widely associated with two integron classes (1 and 2) in MDR- and XDR-UPEC strains.

Genomic diversity and antimicrobial susceptibility profiling of nasal carriage Staphylococcus aureus isolated from pediatric ward in Western Iran

Nasal carriage of Staphylococcus aureus (S. aureus) probably causes the transmission of infection between individuals in hospital and community. This study aimed to evaluate the molecular epidemiology and antibiotic resistance pattern of nasal carriage S. aureus in pediatric ward patients and personnel. A total of 122 Nasal samples were taken from 28 personnel and 94 hospitalized patients in the pediatric ward. Minimum Inhibitory Concentration (MIC) to vancomycin and cefoxitin was determined by Agar dilution method strips. All S. aureus isolates were analyzed by pulsed-field gel electrophoresis (PFGE). A total of 41 S. aureus were isolated from the patients. 16 isolates (39.09%) were hospital-associated S. aureus (HA-SA) and 25 (60.97%) were community-associated S. aureus (CA-SA); also, 13 S. aureus isolates were obtained from the personnel. Based on MIC results, all of S. aureus isolates were susceptible to vancomycin, and in 41 patient isolates, 13 isolates (31.7%) were resistant to cefoxitin (MRSA). Of 13 S. aureus isolates of the personnel, 3 (23%) isolates were MRSA. Totally 11 common clones and 13 single clones were obtained. In conclusion the prevalence of CA-SA in the ward was higher than that of HA-SA. In the strains obtained from a hospital ward, there was a high epidemiology, genotypic diversity in the studied ward. However, horizontal transfer of S. aureus was observed between patients and between personnel and patients, which indicated the risk of transmission of resistant strains in the hospital wards.