Prevalence of shiga toxins(stx_1,stx_2),eaeA and hly genes of Escherichia coli O157:H7 strains among children with acute gastroenteritis in southern of Iran

Objective:To survey the prevalence severe diarrhea arising from these bacteria in children under 5 years old in Marvdasht.Methods:In this study faecal sample from 615 children aged <5years old who were hospitalized lor gastroenteritis in Fars hospitals in Iran were collected and then enriched in Escherichia coli(E.coli) broth and modified tryplone soy broth with novobiocin media,fermentation of sorbitol,lactose and β— glucoronidase activity of isolated strains was examined by CT—SMAC,VRBA and chromogenic media respectively.Then isolation of E.coli O157:H7 have been confirmed with the use of specific antisera and with multiplex PCR method presence of virulence genes including:xtx_1.stx_2,eae.A.hly has been analyzed.Results:E.coli O157:H7 was detected in 7(1.14%) stool specimens.A significanl difference was seen between detection rale of isolated bacteria from age groups 18-23 months and other age groups(P=0.004).Out of considered virulence genes.only 1 of the isolated strains(0.16%)he stx,and eaeA genes were seen and also all isolated hacleria had resistance to penicillin,ampicillin and erythromycin antibiotics.Conclusions:We found thai children < 2 years of age were at highest risk of infection with E.coli O157:H7.Regarding severity of E.coli O157:H7 pathogenesis,low infectious dose and lack of routine assay for detection ol these bacleria in clinical laboratory,further and completed studies on diagnosis and genolyping of this E.coli O157:H7 strain has been recommended.

Adjuvant activity of Pasteurella multocida A strain,Pasteurella multocida B strain and Salmonella typhimurium bacterial DNA on cellular and humoral immunity responses against Pasteurella multocida specific strain infections in Balb/c mice

Objective: To evaluate the effects of Pasteurella multocida(P. multocida) vaccines on the expression and release of antibodies, interleukin(IL)-6 and IL-12 by serum. Methods: Balb/c mice were immunized with two formalin and iron inactivated vaccine doses within 2 weeks. The vaccines were adjuvant with P. multocida A strain, P. multocida B strain and Salmonella typhimurium bacterial DNA(AbDNA, BbDNA and SbDNA for short, respectively). The animals were challenged 4 weeks after immunization. Blood of mice was collected to detect the change of specific antibody, IL-6, and IL-12 using ELISA. Results: The specific antibody and interleukins in the immunized group increased significantly compared to the control mice after vaccination and challenge(P<0.05). The highest release of these cytokines was obtained by P.multocida inactivated with iron and adjuvant with AbDNA at a concentration of 25 μg/mL. The antibody titer peak was 0.447 in mice vaccinated with iron-killed whole-cell antigen adjunct with AbDNA. The time-courses of release showed that bacterial DNA was able to stimulate IL-6 and IL-12 production more than alum(P<0.05). Conclusions: Our findings introduce that bacterial DNA is capable of releasing an immunological response with several cytokines.These indicate that bacterial DNA entrapped with killed P. multocida antigen is a new and effective adjuvant to enhance specific immunity and resistance of animal against the infectious pathogen, which could simplify the development of highly promising strong adjuvant.

A simple multiplex PCR for assessing prevalence of extended-spectrumβ-lactamases producing Klebsiella pneumoniae in Intensive Care Units of a referral hospital in Shiraz,Iran

Objective:To identify three common genes(bla_(TEM),bla_(SHV)and bla_(CTX-M)responsible for ESBL production in Klebsiella pneumnniae(K.pneumnniae)isolated from Intensive Care Units of Namazi Hospital,Shiraz,Iran.Methods:A total of 60 non-repetitive nosocomial isolates from 60patients were selected during 2009-2010.The phenotypic identification of ESBL production was confirmed by Double Disk Synergy Test(DDST)according to CLSI guidelines.The ESBL's genotype was then analyzed by multiplex PCR of bla_(TEM),bla_(SHV)and bla_(CTX-M)genes and DNA sequencing.Results:The primary susceptibility tests of K.pneumoniae showed that among 10 examined antibiotics,the most resistant and susceptible antibiotics identified in this study were ampicillin and imipenem,respectively.The phenotypic determination of ESBL by DDST showed that 60%(n=36)of isolates produced ESBL.Multiplex PCR of genes among K.pneuunoniae isolates showed that 39%(n=18)of them have TEM,39%in=18)of then have both CTX-M and TEM and 13%(n=8)of them have TEM,SHV,CTX-M.Conclusions:Our findings reveal the high prevalence(60%)of ESBL prcxducing K.pneumnniae from ICL patients along with a new pattern of bla_(TEM)distribution differ from other countries.

The relationship between <i>Helicobacter pylori</i>disease and bacterial count in stomach

Several studies showed significant relationships between bacterial counts and the severity and type of disease in patients. The aim of this study was to evaluate the relationship between Helicobacter pylori disease and bacterial count. In this study, 287 patients with dyspeptic symptoms were evaluated. Three variables including patient-reported data, clinical signs and bacterial load of gastric specimens were analyzed. Biopsy samples were collected from patients who were referred for endoscopies because of dyspeptic symptoms. Initially, the clinical status was evaluated and recorded by a questionnaire. DNA extraction was performed and H. pylori was analyzed for bacterial count by Real-time PCR assay and specific primers and probe. The variety range of bacteria in specimens was 104 to 1012. The results revealed that a greater relationships existed between 1012 and gastric cancer (p = 0.036), also 104 and acid reflux (p = 0.006) and vomiting (p = 0.047). Real-time PCR assay provides a highly accurate, rapid and precise method for detection of H. pylori and determination of progressive disease due to this bacterium.