Background and objective: Echerichia coli (E.COLI) a coccobacillus from enterobacteriaceae family causes different diseases in human, and is the most common gram- negative bacterium, causing urinary tract infection. It can also produce bacteremia, gallbladder and billiary tract, gastrointestinal and wound infection. Although E.COLI is known as an antibiotic- sensitive bacterium, it's resistance has been increased during past decade.Material and methods: This study was performed on 1042 positive cultures for E.COLI at four laboratories: Shahid Rahnemoon hospital (Yazd), Afshar hospital (Yazd), Ziaie hospital (Ardakan) and central laboratory (Meibod). Data was collected by completing the questionnaires which then analyzed by SPSS software, using chi- square and extended fishers exact test.Results: In this study, sensitivity of E.COLI was at the highest rate to ciprofloxacin (89%), ceftriaxone (86.6%) and chloramphenicol (76.1%), and the highest rate of resistance was to vancomycin (93.1 %) and ampicillin (65.2%). In this survey, the sensitivity rate of samples was different according to the geographic area and clinical isolates. Conclusion: Pattern of antibiotic resistance was different in different areas and clinical samples and this subject requires further studies in the future.

Background: A 57-year-old Iranian woman with a 4-day history of fever, malaise, and disorientation is presented. Signs of meningeal irritation were evident on examination. The patient’s medical history was remarkable for diabetes mellitus, and hypertension with several admissions to hospital. Ampicilin, ceftriaxon, and vancomycin were administered for possible bacterial meningitis. A brain CT scan without contrast was unremarkable. Analysis of CSF revealed compatible values for bacterial meningitis. Culture of urine and CSF samples led to isolation of E. coli. The patient's clinical condition showed no improvement after 3 days. Four days following hospitalization, re-culture of CSF sample again produced positive result for E. coli. Using disk diffusion method, the isolate was found to be resistant to ceftriaxone and imipenem but sensitive to ciprofloxacin. Ceftriaxone was replaced by IV ciprofloxacin plus ceftazidime. The results of repeated analyses of CSF were indicative of clinical improvement with negative result for CSF culture. Ciprofloxacin and ceftazidime were continued for a total of 21 days. The patient remained asymptomatic with no recurrence.

Background: The development of rapid and effective tools for the identification and quantitation of E. coli is of extreme importance in food analysis, environmental monitoring and clinical diagnostics.Methods: The biosensor developed in this work is based on electrochemistry reactions. Therefore, the layout of the sensor is patterned as a two-electrode configuration, working electrode (WE) and reference electrode (RE). The RE were prepared by mixing 1.20 g of graphite powder, which had been heated at 700oC in a muffle furnace for 15 s, with 800 mL of paraffin oil with a mortar and pestle. A WE was prepared in a similar fashion, except that the graphite powder was mixed with a desired weight of bacteriophage. Both RE and WE pastes were packed into a polyethylene tube (2.5 mm diameter), the tip of which had been cut off. Electrical contact to the paste was established via inserting a copper wire thorough flank.Results: Electrochemical experiments were carried out with an electrochemical interface LCR meter as a signal transducer and an electrochemical cell that contains the two-electrode system. The E. coli trapping on bacteriophage was reported by capacitance measurements. Conclusion: In this work, we have successfully fabricated an electrochemical biosensor with bacteriophage electrodes on a paste substrate. The proposed sensors have good characteristics such as; low detection limit, wide concentration, fast response time and good selectivity coefficient for Escherichia coli detection.

Background and Objectives: Serratia is a gram-negative bacterium. The pigmentation property of Serratia Marcescens is used as a marker of dust particles in the environment and in the hospital. Today biopigments are also widely used in the manufacture and production of pharmaceutical products. Prodigiosin is a promising drug due to its reported properties of antifungal immunosuppressive and antiproliferative activities. In the present study, cloning of pig gene-isolated from Serratia Marcescens in Ecoli XL1blue was performed. Subjects and Methods 60 Samples were taken from clinical sources of patients hospitalized with urinary tract infections in Saveh Hospitals. Serratia Marcescens were identified and isolated by different tests. The pig gene was cloned by T-A cloning using PTG-19 vector into the Escherichia coli XL1blue as host. Expression of cloned gene in recombinant colonies was evaluated by Real time PCR. The phylogenetic tree was plotted using clustalX and Mega5 software Results Screening of samples identified 12 isolates of Serratia Marcescens from then 4 isolates had pig gene. Expression of Pig gene in Escherichia coli XL1blue was confirmed by Real-Tima PCR. As a result of phylogenetic studies, some close relatives of serratia have been identified as candidates for further studies Conclusion Serratia Marcescens can be considered as a rich source of pigments with many applications and can be used as indigenous strains to produce Prodigiosin.

Aim and Background: Influenza A is a major cause of mortality in a year. There has been an efficient vaccine available against it since 1960. Antigenic variation is a preventive agent for yearly vaccine production. Now researchers focus on the constant antigens of viruses. M2 protein makes an ionic channel in the coat of influenza, a virus that is effective on infection by virus. This protein is conserved and it is considered as a proper candidate vaccine for influenza infection.Materials and Methods: Due to limitations for influenza virus culture at the lab, the sequence of influenza virus H1N1 strain of Iran was synthesized. It was sub-cloned into pET22b vector recombinant protein and expressed in BL21 E.COLI and confirmed with specific antibody by SDS-PAGE and western blot techniques.Results: The concentration of recombinant M2 protein was 300μg/ml confirmed by specific antibody.Conclusion: Influenza M2 protein could be expressed in BL21 E.COLI host.

Background: This research was carried out for a by considering gene sequence and each amino acid codon in host, which express protein in order of probable vaccine production against influenza A, a major cause of mortality in a year. M2 protein is conserved and it can be a proper candidate vaccine for influenza infection.Materials and Methods: Present research was an experimental study. The sequence of M2 protein of Iran influenza virus H1N1 strain was modified and synthesized. It was subcloned into pET22b vector recombinant protein and expressed in BL21 E.COLI and confirmed with specific antibody by western blot technique.Results: The modified M2 gene was expressed in E.COLI. The concentration of it was 300μg/ml and it was confirmed by western blotting with specific antibody.Conclusion: Influenza M2 protein with modification in sequence could be expressed in BL21 E.COLI host.

INTRODOCTION: Colibacillosis is a common systemic infection caused by E. Coli in poultry. The disease is economically important for poultry producers. In the past strain identification was limit to serotyping and determination of antimicrobial resistance patterns which is not of great value because an identical resistance pattern does not prove that the strains are identical. In present study we compared serotype, antimicrobial resistance pattern, plasmid DNA profiling along with restriction endonuclease analysis for subtyping E. Coli isolated form poultry. MATERIALS & METHODS: A total of 50 strains of E.COLI, was isolated from bile and liver of poultry in several aviaries in Tehran between 1 October 2001 and 15 January 2002. Isolation and identification of strains was carried using standard procedures. Serotyping was performed by agglutination test using the Mst Diagnostic Kit (Mast Group Ltd., Mersey side, UK). Using monovalent and polyvalent serums of the kit only O6 serotype was determined. Serotyping was not possible for all of the isolated strains using the above menthioned kit. All clinical isolated serotypes were routinely tested by single-disk diffusion method against the commonly used antimicrobial agents. RESULTS: 50 strains of E.COLI showed 10 different resistance patterns. The most common antimicrobial resistance pattern was Tiamulin/ Flumequine/ Tetracycline/ Oxytetracycline/ Rifampicin/ Sxt/ Enrofloxacin (28%). Plasmid DNA was extracted by modification of the Birnboim and Doly technique. Isolated Plasmids were separated by electrophoresis on a 0.8% agarose gel in TBE buffer. In all the screened E.COLI strains plasmid of different molecular size were found. Plasmid profile distinguished more strains than did antimicrobial resistance pattern. In 50 E.COLI isolates which showed 10 different patterns of resistance, we found 25 plasmid profiles. Plasmid preparations were further compared by restriction endonuclease digestion, using Hind III, HindII, and EcoRI. In some cases restriction endounclease analysis in one banding pattern plasmid profiles showed heterology between plasmids.CONCLUSION: In this study Plasmid profile analysis distinguished more strains of E.COLI from poultry in comparisom to antimicrobial resistance pattern and serotyping.

When bacteria are exposed to cations or Benzalkonium chloride (from quaternary ammonium compounds) disinfectants, cations attach to phosphate groups of cell membrane phospholipids, whereas unpolar half of the molecule penetrates into hydrophobic part. So as a result there would be some deviation in cell membrane which leads to losing its' semi permeability property, so the nitrogenous and phosphogenous compounds can leave the cell. Furthermore cations entrance into cell causes some change in proteins structure. This antibacterial effect of cations can be reduced by presence of metal ions like Ca++ and Mg++ that probably compete for the anionic places on cell membrane. As water hardness is generally related to its' Ca++ and Mg++ quantity and is calculated by CaC03 (mg/lit) concentration, we studied cations reaction efficiency against water hardness increasment in this research to examine water hardness role in enteric epidemic outbreaks in those areas with hard water in summer. We examined efficiency of two Benzalkonium chloride disinfectants (Mahan and Mass) against three enteric pathogens: Escherichia coli (PTCC 1047), Salmonella enterica (typhimorium serotype PTCC 1340) and Shigella flexnery (PTCC 1234) in 48 alkaline hard water samples with different hardness grades (from 36 to 1610 CaC03 mg/lit). This antibacterial examination was done by dilution and diffusion methods. Results of 720 repeated tests showed that by following the steps mentioned on the label, these disinfectants were able to kill 108/ml of above-mentioned bacteria even in highest understudied water hardness (1610 mg/lit CaC03), but by diluting the examined disinfectants, water hardness could interact with their efficiency. Among three studied pathogens, Salmonella enterica (typhimorium serotype) showed the most resistance to Benzalkonium chloride in hard water. Considering Salmonella epidemic outbreaks in all over the world and also Iran, It is necessary to inform people how to use Benzalkonium Chloride in waters with various hardness as a disinfectant.

Background and purpose: The antibiotics' side effects and microbial resistance have increased the need for natural antimicrobial agents in treating infections. This study aimed to investigate the antimicrobial effects of Nigella sativa extract and its possible nephrotoxicity compared with gentamicin.The effect of N. sativa on gentamicin induced renal toxicity and its synergistic effect were evaluated on urinary tract infection caused by Ecoli in rabbits.Materials and methods: In this experimental study, 36 male New Zealand rabbits were designated into seven groups: gentamicin-bacteria, N. sativa -bacteria, N. sativa -gentamicin-bacteria, N. sativa-gentamicin, bacteria, gentamicin and control groups. The animals were anesthetized after ten days of treatment, and the kidney specimens were collated for histopathological examination. The nephrotoxic effects of gentamicin and protective effects of N. sativa on kidney were studied. Antibacterial effects of the extracts were evaluated with laboratory tests and the MBC and MIC values were obtained for N. sativa.Results: The level of urea nitrogen and creatinine in urine increased in bacteria group compared to control group (P<0.05). But, they decreased in bacteria-N. sativa group compared with the bacterial group (P<0.05). Histopathological examination of kidney tissue showed that renal lesions in bacterial and, bacteria- gentamicin groups (ATN) were more than N. sativa -bacteria and bacteria-gentamycin- N. sativa (minor necrosis) groups.Conclusion: According to the results, N. sativa in addition to antibacterial effect against E. coli, can prevent the nephrotoxic effects of gentamicin. Therefore, it may be considered as an alternative, or in combination with gentamicin.