Jorjani Biomedicine Journal

Background and Objectives: Escherichia coli (E.coli) is one of the most common bacteria causing urinary tract infections which has become resistant to beta-lactam antibiotics due to the acquisition of plasmids encoding extended-spectrum beta-lactamases (ESBL). Here, we investigated the phenotype and genotype of Cefotaxsim-M (CTX-M) gene among ESBL-producing Escherichia coli among urine samples of patients reffering to Yahyanejad hospital of Babol city.

Methods: The present cross-sectional study was conducted among all 1842 patients referring to Yahyanejad hospital since June to December of 2015. Disc diffusion method was used to evaluate the bacterial resistance to cefotaxime, meropenem, gentamicin, amikacin, ciprofloxacin, ceftriaxone, nitrofurantoin and nalidixic acid. The resistant strains were also confirmed using a combination of cefotaxime-clavulanic acid and ceftazidime-clavulanic acid discs. The presence of CTX-M gene was evaluated among ESBL-producing strains by Real time PCR. SPSS 20 software and chi-square test were used to analyze data statistically.

Results: A total of 84 E.coli isolates were detected in all specimens. The most sensitivities were against amikacin (91.67%), meropenem (96.43%), ampicillin/sulbactam (95.24%) and  piperacillin/tazobactam (94.5%). However, the highest resistancies were against nalidixic acid (83%) , doxycycline/ salicilin (70%), ceftriaxone (46.63 %) and ciprofloxacin (51.2%). Twenty-nine isolates (34.5%) produced ESBL. The CTX-M positive ESBL-producing E-coli was 69%. There was a significant relationship between the presence of CTX-M gene and ESBL (P-value = 0.03).

Conclusion: In the present study, the presence of beta-lactamase-producing genes (CTX-M) in E.coli strains were markedly high. Therefore, the consumption of antibiotics should be controled and further phenotypic and genotypic studies on bacterial pathogens should be conducted.

Background and Objectives: Nowadays, to avoid the use of synthetic preservatives, which do more harm than good, numerous studies are currently focused on using natural ingredients to enhance food product quality and shelf life. Since no study has been conducted on combining coatings with electrolyzed water containing natural antimicrobial compounds, the present study has innovation and priority. In the present study, the effect of chitosan coating prepared through Neutral Electrolyzed Water (NEW) on inhibiting the growth of Escherichia coli O157:H7 inoculated in rainbow trout fillet over 12 days at 4 ˚C was examined.
Material and Methods: Fish samples were allocated into six groups following inoculation with E. coli O₁₅₇:H₇ (final concentration: ~ 10⁵ CFU/g). Treatments included control (CON), distilled water (DW), neutral electrolyzed water (NEW), chitosan 2% (CH), chitosan coating prepared by neutral electrolyzed water (CH/NEW), and neutral electrolyzed water followed by chitosan (NEW+CH). Treatments were kept at low temperature (refrigerator) and counting bacteria was done on 0, 1^st, 3^rd, 6^th, 9^th, and 12^th days. Data analyses were done through repeated measure ANVOA and Bonferroni post hoc tests.
Results: As indicated by the findings, the reduction rate of EW, CH, CH+WE, and CH/EW samples were 1.04, 1.45, 2.01, and 2.02 log CFU/g compared with the CON, respectively. The highest reduction rate was observed in the CH/NEW sample, due to the antimicrobial activity of chitosan and neutral electrolyzed water.
Conclusion: Chitosan coating can be combined with NEW in fish to increase the safety against pathogenic bacteria and E. coli O₁₅₇:H₇. Therefore, it can suggest the use of these natural antimicrobial compounds in the food industry.