Comparison of Genetic Patterns of E. coli Strains Isolated from Patients with Cystitis and Pyelonephritis, Using Pulsed Field Gel Electrophoresis

Abstract: Background & Aims: Urinary tract infection (UTI) is one of the most frequently acquired bacterial infections caused by a large genetically heterogeneous group of Escherichia coli which are called uropathogenic E. coli (UPEC). Cystitis and pyelonephritis are two most common symptoms seen in patients with UTI. The genetic diversity of this organism has hampered the identification of UTI strains and it is unclear whether all UPEC isolates are capable of causing both cystitis and pyelonephritis. Therefore, Careful selection of appropriate genotyping methods is mandatory. The most popular method is Pulsed Field Gel Electrophoresis (PFGE) that is used in the present study to evaluate the genetic patterns of UPEC. Methods: In this cross-sectional study a total of 90 E. coli strains consisting of 48 isolates causing pyelonephritis and 42 isolates causing cystitis in children were analyzed by PFGE and their corresponding patterns were compared. Results: Sixty six PFGE profiles were obtained from the genome of E. coli strains by this genotyping method. Most strains exhibited twelve and thirteen bands and the patterns with eight or nineteen bands had the lowest rate. Genome size of strains was between 1610-4170 kbp. Conclusion: According to these results, it can be suggested that in some cases the strains causing pyelonephritis or cystitis have common patterns and different clinical symptoms could be attributed to different gene factors. Keywords: Escherichia coli, Pyelonephritis, Cystitis, Pulsed Field Gel Electrophoresis » XM

Antibiotic Susceptibility Patterns and Molecular Epidemiology of Metallo-β-Lactamase Producing Pseudomonas Aeruginosa Strains Isolated From Burn Patients.

BACKGROUND: Failure in the treatment of burn patients infected with Pseudomonas aeruginosa could happen as a result of the acquisition of antibiotic resistance, including carbapenems. OBJECTIVES: The aim of the present study was to investigate the phenotypic and genotypic characteristics of the Pseudomonas aeruginosa strains, isolated from burn patients. PATIENTS AND METHODS: During a 12 month period, in this cross-sectional study, two hundred seventy strains of Pseudomonas aeruginosa were isolated from the burn patients in Ghotbeddin Burn Hospital, Shiraz, Iran. Screening for the carbapenem resistance in the isolates was carried out by the E test method. Sensitivity patterns of metallo-β-lactamase (MβLs) producing strains of pseudomonas to eleven antibiotics were determined by the mentioned method. The epidemiological associations of these strains were determined by Pulsed-field gel electrophoresis (PFGE). RESULTS: Of the 270 strains, 60 (22.2%) were resistant to imipenem and meropenem, classified as MβLs producing. MβLs producing strains of pseudomonas were completely resistant to five tested antibiotics while their sensitivities to the three most effective antibiotics including ceftazidime, amikacin and ciprofloxacin were 23.4%, 6.7 % and 1.7%, respectively. In PFGE, 37 patterns from the genome of Pseudomonas aeruginosa were observed. Majority of the strains (43; 71.6%) exhibited more than 80% similarity, based on the drawn dendrogram. CONCLUSIONS: According to the results, none of the tested antibiotics is safe to prescribe. As PFGE revealed, a limited number of Pseudomonas aeruginosa types are predominant in the hospitals which infect the burn patients

Burn Patients Infected With Metallo-Beta-Lactamase-Producing Pseudomonas aeruginosa: Multidrug-Resistant Strains

Background: Metallo-beta-lactamase (MBL) producing Pseudomonas aeruginosa in the burn patients is a leading cause of morbidity and mortality and remains a serious health concern among the clinicians. Objectives: The aim of this study was to detect MBL-producing P. aeruginosa in burn patients and determine multidrug-resistant (MDR) strains, and respective resistance patterns. Patients and Methods: In this cross-sectional study, 270 strains of P. aeruginosa were isolated from the burn patients referred to Ghotbeddin Burn Hospital, Shiraz, Iran. Among them, 55 MBL-producing P. aeruginosa strains were isolated from 55 patients hospitalized in burn unit. Minimum inhibitory concentrations (MICs) and MBLs were determined by the E-test method. Results: Of the 55 burn cases, 29 (53%) were females and 26 (47%) males. Injured burn patients’ ages ranged from 16 to 87 years, with maximum number of cases in the age group of 16 to 36 years (n, 40; 72.7%). Overall, 32 cases were accidental (60%), and 22 were suicidal burns (40%). Of the 55 burn patients, 17 cases were expired (30%). All deaths were due to chemical exposures. In antibiotic susceptibility testing by E-test method, ceftazidime was the most effective one and 35 isolates (63.5%) were resistant to all the 11 tested antibiotics. Conclusions: Routine microbiological surveillance and careful in vitro testing of antibiotics prior to prescription and strict adherence to hospital antibiotic policy may help to prevent, treat, and control MDR and pandrug-resistant (PDR) P. aeruginosa strains in burn units

Health assessment of Arsenic and Zinc in rice cultivated in Fars province (Case Study: Firoozabad fields)

Food security along with the protection of environment has become a global issue.Accumulation of Arsenic and Zinc in rice is considered as a major problem for South-East Asia, where rice is a staple food. Given that, rice is considered as the highly consumed food in the diet of Iranian people, this study was conducted to estimate the concentrations of Zinc and Arsenic in rice cultivated in Firoozabad fields. For this purpose, 38 rice samples were collected from 22 nearby villages. Samples were digested by Digesdahl device and the concentrations of Arsenic and Zinc were determined by ICP. The results showed that the concentration (mean ± SD) of Zinc was 20.87 ± 1.9 mg/kg of dry matter (ranged from 25.26 to 32.97); meanwhile mean value of Arsenic concentration was estimated at 22.89 ± 2.2 mg/kg of dry matter (ranged from 17.61 to 26.77).Comparing the concentrations of Arsenic and Zinc in rice samples with the standard limit set by WHO/FAO it was revealed that Arsenic concentrations in 100% of the samples were higher than standard level, whereas Zinc concentrations in 97.36% of the samples were below the limit

Integron and genotype patterns of quinolones-resistant uropathogenic Escherichia coli

Uropathogenic Escherichia coli are the most common cause of urinary tract infections, and quinolonesresistant strains cause growing concern in developing countries. This study provides relevant data in relation to the molecular epidemiology of these isolates with respect to the distribution of integron among them and in doing so, to control the infections and adopt efficient strategies. This study was performed on 96 strains of E. coli isolated from patients with community acquired urinary tract infections in Jahrom, Iran. Having determined the antibiotic susceptibility patterns, isolates were resistant to quinolones (Ciprofloxacin, Norfloxacin and Nalidixic acid) screened for integron classes by polymerase chain reaction (PCR). Then the genetic patterns of the strains were compared by pulsed field gel electrophoresis. Of the 96 samples, 30 were resistant to at least one of the above mentioned antibiotics. Integrons were detected in 20.8, 25 and 25% of the Nalidixic acid, Ciprofloxacin and Norfloxacin resistant isolates, respectively. By using pulsed field gel electrophoresis among the 30 samples, we obtained 30 genetic patterns. The patterns revealed no clonal relationships between the strains. The gene cassettes observed in class 1 and 2 integrons did not correlate completely with the quinolone resistance observed in these isolates

Molecular Epidemiology of Pseudomonas aeruginosa Isolated from Burn Patients

Background & aim: Because of emerging multi-drug resistance (MDR) Pseudomonas aeruginosa strains, treatment of burn patients infected by this bacterium is difficult. The aim of this study was to detect antimicrobial profile and molecular epidemiology of metallo-beta-lactamase (MBL) producer strains. Methods: In this cross-sectional investigation 270 Pseudomonas aeruginosa isolates were collected from the burn patients. Carbapenem sresistance strains were detected by phenotypic E-test method. Susceptibility profiles of metallo-β-lactamase (MβL) enzyme producing isolates of this bacterium to 11 antimicrobial drug were determined by disc diffusion method according Clinical and Laboratory Standards Institute (CLSI) guidelines. The genetic correlations between isolates were determined by Pulsed-Field Gel Electrophoresis (PFGE) method. Results: Among 270 P. aeruginosa isolates, 60 (22.2%) strains showed resistant to meropenem (MEM) and imipenem (IMI) and were considered as metallo-β-lactamase positive. All metallo-β-lactamase positive isolates were resistant to five tested antimcrobial while their sensitivities to the three best effective antibiotics including ciprofloxacin, amikacin and ceftazidime were 1.7%, 6.7 % and 23.3%, respectively. Majority of the isolates (71.6%) showed more than 80% similarity based on the drawn dendrogram. Conclusion: Our results showed, the tested antimicrobials are not safe to prescribe for burn patients. According PFGE pulsotypes, a limited number of P.aeruginosa types are common in the hospital burn unit which infect the patients hospitalized in this ward

Genotypic analysis of E. coli strains isolated from patients with cystitis and pyelonephritis

BACKGROUND: Urinary tract infection is the most common health problem affecting millions of people each year, mainly caused by a large genetically heterogeneous group of Escherichia coli called uropathogenic E. coli This study investigates the genotypic analysis of E. coli strains isolated from patients with cystitis and pyelonephritis. METHODS: During 2008-2009, 90 E. coli strains were analyzed, consisting of 48 isolates causing pyelonephritis in children and 42 isolates causing cystitis. Having identified the strains by standard methods, they were subtyped by pulsed field gel electrophoresis (PFGE) and their corresponding patterns were compared using dendrogram. RESULTS: Sixty five PFGE profiles were obtained from the genome of E. coli strains by this genotyping method. Thirty six and thirty three patterns were obtained for pyelonephritis and cystitis, respectively. Most strains exhi-bited twelve and thirteen bands and the patterns with eight or nineteen bands had the lowest rate. Genome sizes of the strains were between 1610-4170 kbp. CONCLUSION: With due attention to these results, genetic patterns showed that the strains had different clonalities and it could be suggested in some cases that the strains causing pyelonephritis or cystitis have common patterns and different diseases could be explained by different gene factors

Enteroaggregative Escherichia Coli (EAEC) in South of Iran

Introduction:  The aim of the present study was to investigate the presence and the frequency of EAEC as etiologic agent of diarrhea in Shiraz. Enteroaggregative E. coli (EAEC) is increasingly recognized as a cause of often persistent diarrhoea in children and adults in both developing and developed countries, and have been identified as the cause of several outbreaks worldwide.   Materials and Method: A total of 715 stool samples were collected from patients with diarrhea in Shiraz. Diarrheagenic E. coli were isolated by biochemical tests and culture from 715 stool samples collected from different hospitals. Diarrheagenic E. coli strains isolated from diarrheal stool samples were examined for the detection of the aggR gene by Real time PCR and PCR method.   Results: In this study, a total of 101 (14.12%) diarrheagenic E. coli were isolated from 715 stool samples collected from different hospitals. Diarrheagenic E. coli were isolated much more frequently in the summer months than other season. Out of these 101 diarrheagenic E. coli identified, 5 were confirmed as EAEC in patient. The high prevalence of EAEC isolates was also found in watery diarrhea.   Conclusion: We therefore, recommend the routine isolation and identification of EAEC strains from patient with diarrhea in all the clinical laboratories and other pathotype diarrhoeagenic E. coli in Iran.   Keywords: Diarrhea, Enteroaggregative Escherichia coli (EAEC), Real-Time PCR