Background: Shigella spp. are primary pathogens of diarrhea in children worldwide. Emergence of resistance to fluoroquinolones and third-generation cephalosporins is crucial in the management of pediatric shigellosis. We determined the prevalence and the antibiotic resistance patterns of Shigella species isolated from pediatric patients in central Iran. Materials and methods: Pediatric diarrhea samples (n=230) were cultured on MacConkey and XLD agar media and in GN broth. Genus-specific PCR for ipaH was also used for detection directly from fecal specimens. Antibiotic resistance and the frequency of ESBL and AmpC genes were determined. Results: Out of the 230 samples, 19 (8.2%) cases of Shigella spp. were identified using culture. Twenty-six samples were positive by PCR (11.3%), S. flexneri (4/19; 21%) and S. sonnei (15/19; 78.9%) being the most detected. The highest antibiotic resistance rates were found for cotrimoxazole (19/19; 100%), ampicillin (16/19; 84.2%), cefixime (13/19; 68.4%) and ceftriaxone (12/19; 63.1%). Ten cases showed phenotypic ESBL presence and all these strains were positive for bla TEM , bla CTX-M-1 , and bla CTX-M-15 . Three strains were AmpC positive, all of which harbored bla CMY-2 and two contained bla CIT . Of the 19 Shigella isolates 5 (26.3%), 2 (10.5%), and 1 (5.2%) were phenotypically resistant to nalidixic acid, ciprofloxacin, and norfloxacin, respectively. Class 1 integron was found in 18 (94.7%) isolates whereas class 2 integron was found in 19 (100%) strains. Conclusion: We found a considerable presence of Shigella species with elevated antibiotic resistance levels. In particular, the resistance to third-generation cephalosporins (ESBL) and ciprofloxacin must be taken seriously.

Background:Staphylococcus aureus is one of the most common causes of nosocomial infections and its resistance to antibiotics is a global concern. Lysostaphin is an antimicrobial agent belonging to a major class of antimicrobial peptides and proteins known as the bacteriocins. It exhibits a high degree of anti-staphylococcal bacteriolytic activity.Objectives:In this study, high level of recombinant mature lysostaphin in Escherichia coli was produced by using pET32a expression vector.Materials and Methods:The S. simulans gene encoding lysostaphin was extracted, amplified by polymerase chain reaction (PCR), and sub-cloned in prokaryotic expression vector pET32a. E. coli BL21 (DE3) plysS were transformed with pET32a-lys and gene expression was induced by IPTG. The expressed protein was purified by affinity-chromatography using (Ni-NTA) resin.Results:PCR and sequencing results confirmed the successful cloning of the target gene into the vector. The expression of protein was induced by IPTG and high concentration of the recombinant protein was obtained via the purification process by affinity-chromatography.Conclusions:Our data showed that the recombinant mature lysostaphin protein produced by pET32a vector in E. coli system was very efficient.

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In this study, effect of ethanol extract of Saffron (Crocus sativus L.) in the treatment of Experimental Autoimmune Encephalomyelitis (EAE) in C57BL/6 mice was evaluated. EAE was induced by immunization of 8 week old mice with MOG(35-55) with complete Freunds adjuvant. Therapy with saffron was started on day the immunization. Total Antioxidant Capacity (TAC) was assessed by Ferric Reducing-Antioxidant Power (FRAP) method. Nitric oxide (NO) production was also estimated by Griess reaction. For histological analysis, mice brain was harvested and sections were stained with Hematoxylin-Eosin. After daily oral dosage the saffron significantly reduced the clinical symptoms in C57BL/6 mice with EAE. Also, treated mice displayed a delayed disease onset compared with control mice. TAC production was significantly elevated in saffron treated mice. Effect of saffron on serum NO production was not significant. Typical spinal cord leukocyte infiltration was observed in control mice compared with saffron treated mice. These results suggest for the first time that saffron is effective in the prevention of symptomatic EAE by inhibition of oxidative stress and leukocyte infiltration to CNS and may be potentially useful for the treatment of Multiple Sclerosis (MS).