Browsing by Author "Sadegh Ghorbani-Dalini"
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- ItemThe Association of Virulence Determinants of Uropathogenic Escherichia coli With Antibiotic Resistance(Brieflands, 2014-05-01) Sara Asadi; Mohammad Kargar; Kavous Solhjoo; Akram Najafi; Sadegh Ghorbani-DaliniBackground: The emergence of antimicrobial resistant strains of Escherichia coli has raised considerable interest in understanding the diversity and epidemiology of E. coli infections in humans. Virulence factors of E. coli determine the specific infections caused by this microorganism. Objectives: This study aimed to determine the prevalence of eight E. coli virulence factors and their association with antimicrobial resistance in bacteria isolated from patients with urinary tract infections (UTI). Patients and Methods: One thousand patients with UTI were enrolled in this cross-sectional study. Antimicrobial susceptibility was examined by disc diffusion method according to CLSI guidelines. After DNA extraction, the materials were probed by PCR for eight virulence factors genes, namely fimH, hly, iucC, ibeA, sfa/foc, neuC, papC, and afa genes. Results: The frequency of virulence factors papC, afa, sfa/foc, fimH, hly, neuC, ibeA, and iucC were 53.3%, 51.7%, 53.3%, 56.7%, 23.3%, 31.7%, 20%, and 73.3%, respectively. In addition, there was a high degree resistance to cotrimoxazole and nalidixic acid while a high degree of susceptibility to nitrofurantoin was detected. There was a statistically significant association between fimH gene and resistance to ciprofloxacin (P = 0.006), nalidixic acid (P = 0.025), and cotrimoxazole (P = 0.02). Such associations were found between ibeA gene and amikacin (P = 0.02) and cotrimoxazole (P = 0.02) as well as between afa gene and gentamycin (P = 0.05). Conclusions: The results showed that E. coli isolated from patients with UTI had eight virulence factors with high frequencies. Moreover, these results alleged a direct connection between virulence factors and antimicrobial resistance in E. coli.
- ItemMolecular Detection of Diffusely Adherent Escherichia coli Strains Associated with Diarrhea in Shiraz, Iran(Brieflands, 2017-04-01) Pejman Abbasi; Mohammad Kargar; Abbas Doosti; Jalal Mardaneh; Sadegh Ghorbani-Dalini; Mohammad Ali DehyadegariBackground: Diarrhea continues to be one of the most common causes of morbidity and mortality among children in developing countries. Recently, some studies have implicated diffusely adherent Escherichia coli (DAEC) strains as a cause of diarrhea. The clinical manifestations of diarrhea caused by DAEC strains may include watery or bloody diarrhea, abdominal pain, dehydration, and fever. Objectives: The aims of this study were (1) isolation of E. coli from fecal samples obtained from patients with diarrhea in Shiraz (Iran), (2) detection of DAEC pathotypes in isolates by molecular diagnostic techniques such as conventional PCR and real-time PCR assays, and (3) investigation of the antibiotic susceptibility of DAEC isolates. Materials and Methods: Seven hundred and fifteen stool specimens of diarrhea patients were collected in Shiraz, Fars, Iran. Diarrheagenic E. coli strains were isolated by standard biochemical analysis. Susceptibility testing was performed by the diffusion method, according to the guidelines of the Clinical and Laboratory Standards Institute. Real-time PCR and conventional PCR were used to detect the daaD gene in the DAEC strains isolated. Results: Of the 715 stool samples tested, 101 (14.1%) were identified as E. coli by biochemical tests and culture. Of the infected patients, 58 (57%) were male and 43 (43%) were female, with a mean age of 13.52 (SD, 1.66) years. Eight of the E. coli strains were identified as DAEC strains. The most effective antibiotics against the DAEC isolated were levofloxacin and imipenem, and the least effective antibiotics were ampicillin and penicillin. Conclusions: Our analysis indicated that DAEC strains may be considered as potential pathogens in Shiraz, southern Iran. Further, although the prevalence of DAEC is low, prevention of infection caused by this bacterium among asymptomatic patients is crucial. Therefore, further characterization of the different virulence aspects of DAEC strains is required.
- ItemMolecular Epidemiology of ESBL Genes and Multi-Drug Resistance in Diarrheagenic Escherichia Coli Strains Isolated from Adults in Iran(Brieflands, 2015-10-31) Sadegh Ghorbani-Dalini; Mohammad Kargar; Abbas Doosti; Pejman Abbasi; Meysam SarsharResistance to oxyimino cephalosporins antibiotics in Enterobacteriaceae is primarily done by the extended spectrum β-lactamases (ESBLs). Clear identification of risk factors for ESBLs-producing infections is necessary. Therefore, efficient strategies can be developed to decrease outbreak of these infections. The aim of this study was to determine the antibacterial susceptibility and ESBLs pattern of diarrhogenic Escherichia coli (E. coli) strains isolated from adult patients. In the present study, diarrheogenic E. coli strains were isolated from 54 patients from the University of Medical Sciences hospitals in Shiraz. Antimicrobial susceptibility testing was done by disk diffusion method by CLSI criteria. The presence of blaTEM, blaSHV and blaCTX-M genes was investigated by PCR using designated primers. The prevalence of ESBLs-producer E. coli strains was 12.96%. Antimicrobial resistance testing showed a high resistance to cefexime, trimethoprim-sulfamethoxazole, ampicillin and penicillin. Overall, β-lactamase genes were identified in 52 (96.30%) isolates which were identified as 45 (83.33%) blaTEM, 17 (31.48%) blaSHV and 11 (20.37%) blaCTX-M. ESBLs-producer E. coli is very prevalent in Diarrheogenic strains isolated from adult patients. Also, this study clearly showed that the blaTEM gene for ESBLs-producer E.coli was widespread in Iran.
- ItemOxalate-Degrading Capacities of Gastrointestinal Lactic Acid Bacteria and Urinary Tract Stone Formation(Brieflands, 2013-10-31) Mohammad Kargar; Rouhi Afkari; Sadegh Ghorbani-DaliniBackground: Calcium oxalate is one the most significant causes of human kidney stones. Increasing oxalate uptake results in increased urinary oxalate. Elevated urinary oxalate is one the most important causes of kidney stone formation. This study aims to evaluate oxalate-degrading capacity of lactic acid bacteria and its impact on incidence of kidney stone. Materials and Methods: This case-control study was conducted on serum, urinary, and fecal samples. The research population included a total of 200 subjects divided in two equal groups. They were selected from the patients with urinary tract stones, visiting urologist, and also normal people. The level of calcium, oxalate, and citrate in the urinary samples, parathyroid and calcium in the serum samples, and degrading activity of fecal lactobacillus strains of all the subjects were evaluated. Then, data analysis was carried out using SPSS-11.5, X2 test, Fisher’s exact test, and analysis of variance. Results: The results revealed that the patients had higher urinary level of oxalate and calcium, as well as higher serum level of parathyroid hormone than normal people. In contrast, urinary level of citrate was higher in normal people. In addition, there was a significant difference between the oxalate-degrading capacities of lactobacillus isolated from the patients and their normal peers. Conclusion: Reduction of digestive lactobacillus-related oxalate-degrading capacity and increased serum level of parathyroid hormone can cause elevated urinary level of oxalate and calcium in people with kidney stone.
- ItemThe Sensitivity of the PCR Method for Detection of Coxiella burnetii in the Milk Samples(Brieflands, 2015-06-28) Mohammad Kargar; Afsaneh Rashidi; Abbass Doosti; Akram Najafi; Sadegh Ghorbani-DaliniBackground:: Coxiella burnetii is an obligate intracellular bacterium that causes the zoonotic disease Q fever with a worldwide distribution. Also C. burnetii is classified as a bioterrorism agent. In order to management, prevention and control of Q fever the fast and accurate detection of C. burnetii is necessary. However, the isolation of this strain is very difficult and dangerous. Objectives:: The aim of the study was to evaluate the sensitivity of PCR using different primers for the detection of C. burnetii in milk samples. Materials and Methods:: In this cross-sectional study 70 bovine bulk milk samples were collected randomly from dairy herds in Jahrom, Iran in 2010. All the samples were analyzed for the presence of C. burnetii by PCR targeting 3 different genes (Trans, OMP, Coc). The PCR products were examined by electrophoresis using an agarose gel. Results:: The frequency of C. burnetii in the evaluated samples using Trans-PCR, OMP-PCR and Coc-PCR were 17.14%, 10% and 10%, respectively. Conclusions:: The results of this study show that Trans-PCR is highly sensitive and useful for the direct detection of C. burnetii in milk samples. This technique is a one-step and fast process in comparison to the other assays.