Detection of Antimicrobial Susceptibility and Integrons Among Extended-spectrum β-lactamase Producing Uropathogenic Escherichia coli Isolates in Southwestern Iran

Integron distribution and relationship to antimicrobial resistance in E. coli isolated from blood culture

PURPOSE

The aim of this study was to evaluate the distribution of integrons in strains of E. coli isolated from blood culture and the relationship between integrons and antimicrobial resistance.

METHODS

The study included 100 E. coli strains sent to the Medical Microbiology Laboratory from different clinics between September 2022 and June 2023. Antibiotic susceptibility was evaluated according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). The presence of integrons was determined by the inhouse polymerase chain reaction (PCR).

RESULTS

Integron positivity was detected in 45 (45%) of isolates, and class 1 integrons were found in 41 (41%), class 2 integrons in 2 (2%), and both class 1 integrons and class 2 integrons in 2 (2%). Class 3 integron positivity was not detected. In total, 63 cases of community origin and 37 cases of hospital origin were identified. When antibiotic resistance was evaluated, the highest sensitivity was noted for amikacin (1%), meropenem (5%), imipenem (6%), and the highest resistant antibiotics were ampicillin (82%), cepfuroxime sodium (65%), and amoxicillin/clavulanate (62%), respectively. Of the 16 antimicrobial substances evaluated, 10 had an antibiotic resistance rate of over 45%. In class 1 integron-positive samples, ampicillin resistance and trimethoprim/sulfamethoxazole resistance were higher than in negative samples (p = 0.02, p = 0.0001, respectively). Fifty-one (51%) samples were found to have multiple drug resistance (MDR). In total, 59.5% of hospital-acquired isolates and 46% of community-acquired isolates were considered to be MDR. The class 1 integron positivity in MDR samples was high (p = 0.038).

CONCLUSION

The high MDR rates in both hospital-acquired and community-acquired isolates are alarming. In particular, class 1 integron monitoring is very important to prevent the spread of MDR isolates.

Characterization of integrons, extended spectrum beta lactamases and genetic diversity among uropathogenic Escherichia coli isolates from Kerman, south east of Iran

Background and Objectives

The study aimed to investigate the distribution of genes encoding integrons, extended spectrum beta-lactamase (ESBL) in E. coli isolated from UTIs, as well as the genetic diversity among the isolates.

Materials and Methods

E. coli isolates were recovered from the patients with UTI in Kerman Iran. Antibiotic susceptibility was done according to CLSI guidelines. The presence of ESBL genes and integrons was evaluated using PCR. PCR and sequencing were applied for the evaluation of cassette content of integrons. Genotyping of the isolates was performed by multiple-locus variable-number tandem repeat analysis (MLVA).

Results

Imipenem was the most effective antibiotic, while the highest resistance was observed to streptomycin. In total 40.2% of isolates were ESBL producers. Of 69 integron-positive isolates, 59 only had class I integrons, 4 only had class II integrons and 6 had both types. The most common gene cassette found within class I integrons was dfrA17-aadA5 (n=27). The E. coli isolates were divided into 16 MLVA clusters.

Conclusion

The current study demonstrated the simultaneous presence of class I integrons and ESBLs involved in the resistance of UPEC isolates to antibacterial agents. Our finding also revealed that the E. coli isolates belonged to diverse clones.

Dissemination of Class A Cephalosporinases and Class D Carbapenemases in Escherichia coli Isolates From a Tertiary Hospital in Sudan

Introduction The high prevalence of urinary tract infections (UTIs) and rising resistance to beta-lactam antibiotics, which is a global therapeutic concern, are caused by Escherichia coli (E. coli) extended-spectrum beta-lactamases (ESBLs) producers. It is unclear how E. coli that produces ESBLs spreads throughout Gezira state, Sudan. The study aimed to evaluate the dissemination of class A and class D resistance genes among E. coli and to recognize the antibacterial activity of the locally used cephalosporins and carbapenems. Methods One hundred and fifteen isolates of uropathogenic E. coli were collected from patients who attended a tertiary hospital. The isolates were identified using colony morphology, gram staining, and biochemical tests and checked for 16S rRNA using PCR. The multidrug-resistant (MDR) testing was conducted using agar disk diffusion. Finally, the class A and D resistance genes were analyzed by multiplex PCR. Results The study enrolled 200 patients with UTIs. E. coli isolates were found in 115 (57.5%) urine specimens examined, and 60 (52.2%) of them produced resistance to most locally used antibiotics. The antibiotic resistance pattern was higher against cefepime (100%), ceftizoxime (90%), cefuroxime (81.7%), and ceftriaxone (81.7%) and had lower activity against meropenem (13.3%). The genotypic characterization of class A cephalosporinases was 85% for blaCTX-M, 70% for blaSHV, and 33.3% for blaTEM, while for class D carbapenemases, it was 10% for both blaOXA-23 and blaOXA-51. Conclusion The considerable antibiotic resistance to the cephalosporins and meropenem and the increased predominance of the blaCTX-M and blaSHV genes are serious concerns for the health authorities. Meropenem could still be used as the drug of choice for ESBL-producing E. coli.

Antimicrobial susceptibility and integrons detection among extended-spectrum β-lactamase producing Enterobacteriaceae isolates in patients with urinary tract infection

Background

Integrons are bacterial mobile genetic components responsible for mediating the antibiotic resistance process by carrying and spreading antimicrobial resistance genes among bacteria through horizontal gene transfer.

Objectives

This cross-sectional hospital-based study aimed to find the prevalence of antibiotic resistance patterns and to detect integrons classes (I, II, and III) among bacterial isolates in patients with urinary tract infections (UTI) in Sulaimani, Iraq.

Patients and Methods

Mid-stream urine samples (no. = 400) were collected from patients with UTI at three different Hospitals from Sulaimani, Iraq, between September 2021 to January 2022. Urine samples were cultured on various agar media, and grown bacteria were isolated. Antibiotic susceptibility test (AST) and an extended-spectrum β-lactamase (ESBL) screen were done for isolated bacteria. Then, integrons classes were screened using conventional PCR with gene sequencing and uploaded to the National Center for Biotechnology Information (NCBI).

Results

The frequency rate of Enterobacteriaceae was 67.03% among positive urine cultures. E. coli (no. = 86) and Klebsiella pneumoniae (no. = 32) isolates were identified. The most sensitive antibiotics were the carbapenem group (85.3%) and nitrofurantoin (NFN) (64.2%), while the most resistant antibiotics were nalidixic acid (NA) and 3^rd generation cephalosporin. The occurrence rate of ESBL was 56.6% with a predominance of class I integron (54.2%), then class II (15.8%) and no positive record for class III integron were observed.

Conclusion

Most bacterial isolates from patients with UTI produced class I and II integrons genes with favourable ESBL properties.

High prevalence of extensively drug resistant and extended spectrum beta lactamases (ESBLs) producing uropathogenic Escherichia coli isolated from Faisalabad, Pakistan

Urinary tract infections (UTIs) are predominantly caused by uropathogenic Escherichia coli (E. coli). There is rapid increase in antimicrobial resistance in UTIs, also declared as a serious health threat by World Health Organization (WHO). Present study was designed to investigate the antimicrobial resistance status with specific focus on ESBLs and carbapenemases in local uropathogenic E. coli (UPEC) isolates. E. coli isolates were characterized from patients of all ages visiting diagnostic laboratories for urine examination. Demographic data was also recorded for each patient. Antibiograms were developed to observe antibiotic resistance in UPEC using Kirby Bauer disc diffusion technique. Double Disc Synergy test (DDST) was used for phenotypic ESBL test. ESBLs and carbapenemases genes were detected in UPEC using PCR. The PCR results were confirmed by sequencing. The UPEC isolates under study exhibited 78%, 77%, 74%, 72% and 55% resistance against cefotaxime, amoxicillin, erythromycin, ceftriaxone and cefixime, respectively. Resistance against colistin and meropenem was observed in 64% and 34% isolates, respectively. Phenotypic DDST identified 48% isolates as ESBLs producers. Genotypic characterization identified 70%, 74.4% and 49% prevalence of CTXM-1, TEM-1 and CTXM-15 genes respectively. One isolate was observed exhibiting co-existence of all ESBL genes. TEM-1 + CTXM-1 and TEM-1 + CTXM-1 + CTXM-15 + OXA-1 gene patterns were dominant among ESBLs. For carbapenem-resistance, 14% isolates indicated the presence of KPC whereas GES and VIM was detected in 7% and 3.4% isolates, respectively. In conclusion, our results present a high prevalence of extensively drug resistant UPEC isolates with a considerable percentage of ESBL producers. These findings propose the need of continuous surveillance for antimicrobial resistance and targeted antimicrobial therapy.

Phylogenetic groups and antimicrobial resistance characteristics of Escherichia coli strains isolated from clinical samples in North Iran

BACKGROUND AND STUDY AIM

Extraintestinal pathogenic Escherichia coli (ExPEC) is one of the most common bacterial pathogens, which causes a remarkable amount of morbidity and mortality. This study was designed to determine the antibiotic resistance profiles, phylogenetic groups, and subgroup analyses among the ExPEC strains isolated from hospitalized patients in north Iran.

PATIENTS AND METHODS

This cross-sectional investigation was conducted at five educational hospitals in Rasht in north Iran. Using standard microbiological tests, 150 E. coli isolates were identified. The antibiotic susceptibility pattern of all isolates was determined using the disk diffusion method. The double disk phenotypic confirmatory test was performed to detect extended-spectrum β-lactamase (ESBL)-producing isolates. A triplex polymerase chain reaction (PCR) was performed to determine the phylogenetic group of each strain.

RESULTS

The results of antibiogram pattern showed that E. coli isolates were mostly non-susceptible to ampicillin (79.3%), followed by nalidixic acid (75.3%) and cephalothin (70%), whereas nitrofurantoin (94.7%) was the most effective agent, followed by imipenem (92.7%). The rate of ESBL-producing isolates was 53.3% (80/150). Multiplex PCR screening revealed that the most common phylogroup was the B2 group (97 isolates; 64.6%), followed by the D group (34, 22.7%). In contrast, phylogroup analyses showed that B2₃ (50.7%) and D₂ (16.4%) were the most common subgroups.

CONCLUSIONS

Our findings indicated a considerable rate of antibiotic resistance and ESBL-producing isolates among E. coli strains isolated from clinical samples. Moreover, we reported a tendency that most isolates belonged to the B2 and D phylogroups. As a result, the detection of genotypic identical or similar isolates indicated that these isolates have an endurance capability in the hospital environment and could be transmitted among patients.

Antimicrobial Susceptibilities of Urinary Extended-spectrum β-lactamase Escherichia coli to Fosfomycin

Objectives

Escherichia coli (E. coli)-induced urinary tract infection (UTI) is a common infection associated with frequent use of antibiotics and the increase in global antibiotic resistances. We aimed to determine the susceptibility profile of extended-spectrum β-lactamase (ESBL) producing E. coli isolated from the urinary samples to fosfomycin and other antibiotics.

Methods

We retrospectively analyzed urine samples with ESBL-producing E. coli isolates obtained between January 2018 and December 2019 in the Microbiology Section, Salmaniya Medical Complex, Bahrain. We collected and analyzed all the E. coli urinary isolates' data and their antibiotic susceptibility patterns.

Results

The study included 3044 E. coli isolates with 50.6% obtained in 2018 and 49.4% in 2019; 38.1% (1161 isolates) were ESBL E. coli, and 0.7% (21 isolates) were carbapenem-resistant ^{Enterobacteriaceae} (CRE). There were 1161 (38.1%) isolates with ESBL-producing E. coli, with 37.3% isolated in 2018 and 39.0% isolated in 2019. The antibiotic susceptibility of ESBL-producing E. coli during the study period showed susceptibility to trimethoprim/sulfamethoxazole in 46.1% of isolates (50.2% in 2018 dropped to 41.9% in 2019), to ciprofloxacin in 49.0% of isolates (49.5% in 2018 dropped to 48.4% in 2019), to nitrofurantoin in 91.8% of isolates (94.3 in 2018 dropped to 89.3% in 2019), and to fosfomycin in 97.6% of isolates (98.8% in 2018 dropped to 96.3% in 2019).

Conclusions

ESBL-producing E. coli is an important cause of UTI in Bahrain. Fosfomycin is a very effective oral antimicrobial that retains high efficacy against ESBL-producing E. coli, which helps decrease the need for parenteral therapy and, consequently, hospitalization.

Antimicrobial Susceptibilities of Urinary Extended-spectrum β-lactamase Escherichia coli to Fosfomycin

OBJECTIVES

Escherichia coli (E. coli)-induced urinary tract infection (UTI) is a common infection associated with frequent use of antibiotics and the increase in global antibiotic resistances. We aimed to determine the susceptibility profile of extended-spectrum β-lactamase (ESBL) producing E. coli isolated from the urinary samples to fosfomycin and other antibiotics.

METHODS

We retrospectively analyzed urine samples with ESBL-producing E. coli isolates obtained between January 2018 and December 2019 in the Microbiology Section, Salmaniya Medical Complex, Bahrain. We collected and analyzed all the E. coli urinary isolates' data and their antibiotic susceptibility patterns.

RESULTS

The study included 3044 E. coli isolates with 50.6% obtained in 2018 and 49.4% in 2019; 38.1% (1161 isolates) were ESBL E. coli, and 0.7% (21 isolates) were carbapenem-resistant Enterobacteriaceae (CRE). There were 1161 (38.1%) isolates with ESBL-producing E. coli, with 37.3% isolated in 2018 and 39.0% isolated in 2019. The antibiotic susceptibility of ESBL-producing E. coli during the study period showed susceptibility to trimethoprim/sulfamethoxazole in 46.1% of isolates (50.2% in 2018 dropped to 41.9% in 2019), to ciprofloxacin in 49.0% of isolates (49.5% in 2018 dropped to 48.4% in 2019), to nitrofurantoin in 91.8% of isolates (94.3 in 2018 dropped to 89.3% in 2019), and to fosfomycin in 97.6% of isolates (98.8% in 2018 dropped to 96.3% in 2019).

CONCLUSIONS

ESBL-producing E. coli is an important cause of UTI in Bahrain. Fosfomycin is a very effective oral antimicrobial that retains high efficacy against ESBL-producing E. coli, which helps decrease the need for parenteral therapy and, consequently, hospitalization.

The Prevalence of Bacteriospermia in Infertile Men and Association with Semen Quality in Southwestern Iran

INTRODUCTION

Infertility considered as a social and public health issue and estimated that most of these infertile couples are residents of developing countries. Infectious diseases including the history of Sexually Transmitted Infections (STIs) may impact on male reproductive function. Therefore, the present study aimed to investigate the prevalence of bacterial contaminants of semen and probable association with sperm quality of infertile men in Iranian population.

METHODS

The study population consisted of 200 infertile men and 150 fertile men attending an infertility Center in southwestern Iran during the study period in 2015. The assessment of sperm parameters was according to the World Health Organization (WHO) guidelines. The presumptive pathogens were identified using standard microbiology tests and confirmed by specific PCR primers.

RESULTS

The prevalence of bacteriospermia in the semen of the infertile group was significantly higher than that in the fertile group (48% vs. 26.7%, P <0.001). The microbiological analysis of samples showed that the most abundant species of bacteria in semen of infertile men were Chlamydia trachomatis (12.5%) followed by Neisseria gonorrhoeae (11%). On the other hand, in the control group, Lactobacillus spp. (17.3%) was the most isolated pathogen. Results showed that the presence of N. gonorrhoeae, C. trachomatis, Mycoplasma genitalium, Haemophilus, and Klebsiella was significantly associated with sperm abnormality.

CONCLUSIONS

Based on our findings, it seems that bacteriospermia is associated with alterations in the properties of semen which may lead to a decrease in the fertilization potential of sperm. Therefore, immediate and appropriate treatment is necessary before investigating every other possible cause of infertility.

Evaluation of Blood and Liver Cytotoxicity and Apoptosis-necrosis Induced by Nanochelating Based Silver Nanoparticles in Mouse Model

This study aimed to evaluate the in-vitro and in-vivo biological activities of newly synthesized nanochelating based silver nanoparticles (AgNPs) in mouse model. Nanochelating technology was used to design and synthesize the AgNPs. The animals studies were including the lethal dose (LD50) determination by the intraperitoneal administration in mice, and determination of liver enzymes levels and hematological parameters. Flow cytometry analysis was used to quantitatively determine apoptosis and necrotic cells in-vitro. The NPs A and NPs B have LD50 = 250 mg/kg and LD50 = 350 mg/kg, respectively and classified as non-toxic. In general, minor alterations were observed in levels of liver enzymes as indicative of liver damage. For blood parameters several factors associated with significant changes in AgNPs treated animals. Regarding animals weight, combination therapy showed more effective to maintain animals weight losses after infection. Flow cytometry results showed that AgNPs induced cell apoptosis-necrosis depends on AgNP size, concentration and exposure time. Cells damage due to AgNPs (A) with lower size (20-25 nm) were relatively more than cells exposed to AgNPs (B) (30-35 nm). The findings support the potent antibacterial activities of nanochelating based AgNPs. Also, the present study showed that nanochelating based AgNPs induce a moderate level of apoptosis/necrosis in mice, and affected several clinical parameters like blood parameters, liver enzymes, and body weight with no definite signs of toxicity.

The Global Prevalence of Class 1 Integron and Associated Antibiotic Resistance in Escherichia coli from Patients with Urinary Tract Infections, a Systematic Review and Meta-Analysis

Objectives: The present systematic review and meta-analysis study aimed to investigate the prevalence of class 1 integrons and their associated antibiotic resistance in uropathogenic Escherichia coli. Materials and Methods: A systematic search was conducted to identify studies meeting our inclusion criteria in the Web of Science, PubMed, Embase, Scopus, and Google Scholar electronic databases to the end of July 2019. Finally, 35 articles were selected for data extraction, and meta-analysis was performed using the metaprop program in the STATA, version 11.0, software. Results: The pooled prevalence of class 1 integrons was 47% (95% confidence interval [CI]: 40-54), ranging from 6% to 90%. There was significant heterogeneity among the 35 studies (χ² = 840.37; p < 0.001; I² = 95.95%). The results of the subgroup analysis based on characterization of patients indicated that pooled prevalence of class 1 integrons was 52% (95% CI: 41-63; n = 14 studies) and 43% (95% CI: 34-54; n = 19 studies) in hospitalized and community patients, respectively. The lowest and highest prevalence of antibiotic resistance was observed for imipenem and ampicillin, respectively. According to the results of Begg's and Egger's tests, we did not find significant publication bias both in the included studies and in the subgroup analysis. Conclusions: The results show the high prevalence of class 1 integrons and high level of antibiotic resistance in association with those among uropathogenic E. coli. Moreover, the prevalence of class 1 integrons in Asian countries, as well as hospital-acquired urinary tract infection (UTI), was higher than in other countries and community-acquired UTI.

Occurrence of Multidrug-resistant Uropathogens Implicated in Asymptomatic Bacteriuria in Adults with Sickle Cell Disease in Ile-Ife, Southwest Nigeria

OBJECTIVES

We sought to determine the prevalence of asymptomatic bacteriuria (ASB) in patients with sickle cell disease (SCD), the susceptibility profile of its agents and their extended-spectrum β-lactamase (ESBL) production.

METHODS

Fifty-nine patients with SCD and 116 healthy controls were investigated. Urine samples were collected and cultured by standard techniques. We used the disc diffusion technique to determine antibiotic susceptibility. ESBL was detected by the combination disc method and detection of bla SHV, bla TEM, and bla CTX-M genes by multiplex-polymerase chain reaction.

RESULTS

The prevalence of ASB was higher among patients with SCD (8.6%) than controls (0.9%) (p = 0.016), predominantly among females. Coagulase-negative staphylococci (n = 2; 33.3%) predominated among the isolates. Other uropathogens included Stenotrophomonas maltophilia, Acinetobacter baumannii, and Enterobacter cloacae. All isolates were sensitive to meropenem but were resistant to ceftazidime, ampicillin, and tetracycline. bla SHV, bla TEM, and bla CTX-M-15 were detected in Enterobacter cloacae.

CONCLUSIONS

The prevalence of ASB is high in patients with SCD predominantly among females. Rare multidrug-resistant uropathogens were implicated. We posit a need for resistance surveillance programs and antibiotic stewardship to prevent treatment failure and reduce drug resistance.

The Phylogenetic Relatedness of bla NDM-1 Harboring Extended-Spectrum β-Lactamase Producing Uropathogenic Escherichia coli and Klebsiella pneumoniae in the North of Iran

Background

Escherichia coli and Klebsiella pneumoniae as an important part of Enterobacterales family are important causes of both community- and hospital-acquired infections. The present study aimed to investigate the prevalence of antibiotics resistance and molecular characteristics of uropathogenic isolates of E. coli and K. pneumoniae in Iranian patients.

Methods

This cross-sectional study performed on 223 Escherichia coli and 68 Klebsiella pneumoniae isolates obtained from hospitalized patients in the north of Iran. The isolates were identified by standard microbiologic tests and confirmed by API 20E strip. Disk diffusion method was applied to determine antibiotic susceptibility pattern. The presence of β-lactamases encoding genes was evaluated by PCR method. Analysis of the mutations and homology among sequences was done by the CLC sequence viewer (Qiagen, Denmark), and phylogenetic trees were constructed by the neighbor-joining method (Bootstrap: 1000 times).

Results

The overall rates of extended-spectrum β-lactamases (ESBLs)-producing E. coli and K. pneumoniae isolates were 37.7% and 32.4%, respectively. The overall presence of bla_SHV, bla_NDM-1, and bla_OXA-1 genes was detected in 16 (5.5%), 12 (4.1%), and 48 (16.4%) of isolates, respectively. The neighbor-joining analysis for E. coli KU985246.1 strain showed that the most related bla_NDM-1 sequences were from China, Singapore, UK, Thailand, and Bangladesh. While K. pneumoniae KU985245.1 strains were mostly related to bla_NDM-1 sequences form Myanmar, and China.

Conclusion

In summary, the remarkable rate of ESBL-producing uropathogenic Enterobacterales along with the first prevalence of NDM-1 β-lactamases can be a serious concern in our region.

Isolation and Molecular Identification of Aeromonas Wound Infection in Iranian Burn Patients

INTRODUCTION

Aeromonas have recently emerged as opportunistic pathogens and only a few studies are available regarding the isolation of these bacteria from burn wound infections. This study aimed at isolating Aeromonas as an infrequent cause of infection in this group of immunocompromised patients.

METHODS

A total of 300 samples were collected from the wounds of burn patients hospitalized in Gotbodin Shirazi Burn Center in 2013. The samples were cultured on Aeromonas specific media and then confirmed using standard biochemical tests and 16S rRNA gene amplification and sequencing. The antibiotic susceptibility of the isolates was determined using the disk diffusion and broth microdilution methods.

RESULTS

Biochemical tests demonstrated five presumptive samples of Aeromonas, while, molecular testing confirmed only three. All isolates were resistant to ampicillin-sulbactam, erythromycin, oxacillin, and vancomycin. However, they were susceptible to gentamicin, meropenem, nitrofurantoin, chloramphenicol, cephalexin, and cefotaxime. Two Aeromonas veronii isolates were resistant to sulfamethoxazole-trimethoprim and sensitive to nalidixic acid, while Aeromonas bestiarum was sensitive to the former and resistant to the latter antibiotics. Lastly, only one of the A. veronii isolates was found to be resistant to tetracycline.

CONCLUSION

This study is the first to report on the isolation of Aeromonas spp. from burn patients in Iran. Moreover, this is the first report of isolating A. bestiarum from burn wounds. The results of this study confirm earlier findings that the use of molecular methods is essential to accurately identify these bacteria.

Class 1 Integrons in Clinical Multi Drug Resistance <i>E. coli</i>, Sana'a Hospitals, Yemen

BACKGROUND AND OBJECTIVES

The occurrence of multi-drug resistance (MDR) Escherichia coli is one responsible for raised mortality and morbidity and was reported as major health problem. Class 1 integrons has crucial role in distributing antibiotic resistance genes among bacteria. Present work was aimed to determine the prevalence of class 1 integrons and its association with antibiotic resistance in MDR E. coli isolated from patient's body fluid and tissues from 6 health centers in Sana'a, Yemen.

MATERIALS AND METHODS

A cross-sectional study a total of 198 E. coli from patients diagnosed with infection that had been referred to 6 hospitals and medical diagnostic from July, 2017 to August, 2017 in Sana'a, Yemen. Susceptibility of E. coli isolates to 15 antibiotics using the disc diffusion method. Conventional polymerase chain reaction was used for detection of class 1 of integrons in 100 randomly selected MDR E. coli.

RESULTS

Overall 174 (87.9%) of 198 E. coli isolates were MDR. Class 1 integrons were detected in 67% of the randomly selected 100 of 198 MDR E. coli. A significant range (p<0.05-p<0.0001) was identified between presence of class 1 integrons and resistance to ceftriaxone, aztreonam, cefepime, amoxicillin-clavulanic acid, cefotoxime, cefepime-clavulanic acid, ceftazidime-clavulanic acid, ciprofloxacin, ceftazidime, norfloxacin and trimethoprim-sulfamethoxazole, while no significant difference were identified between integron class 1 and resistance to gentamicin, amikacin, nitrofurantoin and imipenem.

CONCLUSION

High MDR E. coli isolates were detected in this study, among them the prevalence of class 1 integrons is the most common. The significant association between class 1 integrons and resistance to common prescribed antibiotics in hospitals in Sana'a, Yemen.

Characterization of antibiotic resistance and virulence factors of Escherichia coli strains isolated from Iranian inpatients with urinary tract infections

Background

Urinary tract infections (UTIs) are one of the most frequent human infectious diseases causing considerable amount of morbidity and mortality. The present study aimed to investigate the occurrence of antibiotics resistance and virulence genes among Escherichia coli strains isolated from UTIs in the north of Iran.

Methods

This cross-sectional study was performed at 5 teaching hospitals in Rasht in the north of Iran. Totally, 129 E. coli isolates were identified by standard microbiologic tests. Antimicrobial susceptibility pattern was determined using disk diffusion method. The presence of virulence genes was detected by PCR method.

Results

The results of antibiotic susceptibility showed that the highest resistance rates were to ampicillin (78.3%) followed by nalidixic acid (74.4%) and trimethoprim/sulfamethoxazole (69.8%). On the other hand, the highest susceptibility was toward nitrofurantoin (96.1%) and imipenem (92.2%). Further analysis revealed that the rate of ESBL-producing and multiple-drug resistant isolates was 51.2% and 84.5%, respectively. Molecular analysis revealed that traaT (87.6%) gene was the most prevalent virulence factors followed by fyuA (86%) and kpsmt (76%) genes. Also, fimH gene was the most frequently detected adhesion-associated gene with 74.4%.

Conclusion

In summary, our results showed a remarkable rate of drug resistance and heterogeneity for virulence factors among E. coli strains isolated from UTIs in the north of Iran. The emergence of such strains can be a predictive marker for their persistence in the hospital and consequently a significant threat for hospitalized patients.

Prevalence of quinolone-resistant uropathogenic Escherichia coli in a tertiary care hospital in south Iran

Background: Quinolones are a family of synthetic antimicrobial agents with a broad antibacterial activity commonly used as a suitable therapy in patients with urinary tract infection (UTI). In the present study, we aimed to evaluate the prevalence of quinolones resistance and the presence of plasmid-mediated quinolone resistance (PMQR) genes among Escherichia coli isolates.

Methods

This study was performed on a collection of 121 E. coli isolates derived from patients with UTI. Antimicrobial susceptibility to nalidixic acid, ciprofloxacin, levofloxacin, norfloxacin, and ofloxacin was specified by the disk diffusion method. The presence of PMQR genes was determined by PCR method.

Results

Antibiotic susceptibility results showed that the highest and lowest resistance rates were against nalidixic acid (71.9%) and norfloxacin (44.6%), respectively. The molecular results showed that 40 (33.1%) and 15 (12.4%) of the isolates were positive for qnrS and qnrB genes, respectively. Meanwhile, 5 (4.1%) of the isolates were found positive for both genes, while none were found to be positive for qnrA gene. There was no significant association between the presence of qnr genes and higher antibiotic resistance.

Conclusion

We found high levels of quinolones resistance (more than 40%) among E. coli strains isolated from patients with UTIs in the south of Iran. We further report the prevalence of PMQR genes among uropathogenic E. coli; however, it seems that these genes are not the main components of quinolone resistance in our region.