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 ß-lactamases, particularly extended-spectrum ß-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.

Epidemiology of toxic shock syndrome toxin-1 harboring Staphylococcus aureus obtained from clinical samples in Iran: A Systematic Review and Meta-analysis.

BACKGROUND: S. aureus strains, with the capability of producing toxic shock syndrome toxin-1 (TSST-1), are more likely to cause complicated infections. However, due to lack of comprehensive local data on the prevalence of TSST-1, we aimed to determine the prevalence of TSST-1 harboring S. aureus isolates in Iran. METHODS: A systematic search was performed by using PubMed and Scopus databases from papers published by Iranian authors from January 2000 to the end of March 2017. Then, 10 publications which were matched with inclusion criteria were selected for data extraction and analysis by Comprehensive Meta-Analysis Software. RESULTS: The overall prevalence of TSST-1 carrying S. aureus in Iran was 21.3% (95% CI: 7.9%-46.1%), ranging from 0% to 68%. Moreover, from the included studies, the pooled prevalence of TSST-1 producing MRSA isolates was estimated to be 25.2% (95% CI: 13.3%-42.5%), ranging from 0% to 69.8%. From those studies which showed the distribution of toxin-harboring S. aureus it was found that the skin and soft tissue, respiratory and bloodstream infections were the common sites of TSST-1 harboring S. aureus. CONCLUSIONS: In summary, it seems that emergence of MRSA strains leads to higher prevalence of TSST-1 carrying strains in the north of Iran. However, further research is required to elucidate the interplay between the outcome of diseases and TSST-1 producing strains, especially in our country.

The presence of extended-spectrum ß-lactamase as a risk factor for MDR in clinical isolation of Escherichia coli.

Significant increases in antibiotic resistance have become a critical dilemma in healthcare systems around the world. Enterobacteriaceae acquired different mechanisms of antibiotic resistance such as ESBLs production and transposon attainment, which hold antibiotic resistance genes. This may create multidrug resistant (MDR) strains. Antibiotic resistance patterns vary in different geographical regions. The present estimated-cross sectional study is aimed to determine antibiotic resistance pattern of 182 E. coli strains to 20 antibiotics. Three different methods were applied to detect the ESBL-producing E. coli. Observations revealed that oxacillin, amoxicillin and ampicillin had the lowest effect, while imipenem, gentamicin and nitrofurantoin had the highest impact on clinical E. coli strains in our region. Three different methods, including double disk synergy test (DDST) (30 mm), double disk synergy test (DDST) (20mm) and combined disk test were used to identify ESBL-producing E. coli. The prevalence of ESBL producers was at a 35.71% rate. Findings of this study indicate that there is no significant difference between these three methods in identifying ESBLproducing E. coli. There was a significant relation between ESBL production and resistance to three other classes of antibiotics, including protein synthesis inhibitor, Quinolones and Metabolite analogues. Moreover, antibiotic resistance rate in ESBL-producing E. coli was significantly higher than non ESBL- producing isolates. The MDR was at a 65.93% rate. Unfortunately, the rate of antibiotic resistance is globally increasing; this is due to several factors such as inappropriate antibiotic use, incomplete course of antibiotics use, protracted length of stay in hospitals and self-medication. Resistance mechanisms such as ESBL production and MDR cause treatment failure. Our findings suggest that ESBL production is a risk factor for MDR in clinical E. coli. Therefore, Physicians are recommended to stop excessive and long term administration of antibiotics.

Effects of pentoxifylline on oxidative stress and levels of EGF and NO in blood of diabetic type-2 patients; a randomized, double-blind placebo-controlled clinical trial.

BACKGROUND: As oxidative stress contributes to both progression and pathologic complications of diabetes and effective therapeutic strategies to prevent or delay the damage remain limited, the aim of the present study was to assess the efficacy of pentoxifylline in reducing of oxidative stress. Since there is a relationship between nitric oxide (NO), epidermal growth factor (EGF) and oxidative stress, we measured the effect of this drug on these parameters in comparison to placebo. METHODS: Thirty-nine patients with type-2 diabetes mellitus were randomized in a double blind, placebo-controlled clinical trial to receive either pentoxifylline 400 mg four times a day or placebo for 14 days. Blood samples were obtained at baseline and at the end of the study. Samples were analyzed for thiobarbituric reactive substances (TBARS) as a marker of lipid peroxidation, ferric reducing ability (total antioxidant power, TAP), EGF and NO levels. RESULTS: Pentoxifylline in comparison to placebo was effective (P < 0.05) in reduction of lipid peroxidation in plasma of the patients without significant effects on TAP, levels of EGF and NO in plasma. CONCLUSION: Adding of pentoxifylline to drug regimen of diabetic type-2 patients can be helpful. Exact mechanism of action of pentoxifylline in reduction of blood lipid peroxidation remains to be elucidated.