Objective:To survey the prevalence severe diarrhea arising from these bacteria in children under5 years old inMarvdasht.Methods:In this study faecal sample from615 children aged <5 years old who were hospitalized for gastroenteritis inFars hospitals inIran were collected and then enriched inEscherichia coli(E. coli) broth and modified tryptone soy broth with novobiocin media.Fermentation of sorbitol, lactose and β-glucoronidase activity of isolated strains was examined byCT-SMAC,VRBA and chromogenic media respectively.Then isolation ofE. coli O157:H7 have been confirmed with the use of specific antisera and with multiplexPCR method presence of virulence genes including: stx1,stx2,eaeA,hly has been analyzed.Results:E. coli O157:H7 was detected in7(1.14%) stool specimens.A significant difference was seen between detection rate of isolated bacteria from age groups18-23 months and other age groups(P=0.004). Out of considered virulence genes, only1 of the isolated strains(0.16%) the stx1 andeaeA genes were seen and also all isolated bacteria had resistance to penicillin, ampicillin and erythromycin antibiotics.Conclusions:We found that children <2 years of age were at highest risk of infection withE. coliO157:H7.Regarding severity ofE. coliO157:H7 pathogenesis, low infectious dose and lack of routine assay for detection of these bacteria in clinical laboratory, further and completed studies on diagnosis and genotyping of thisE. coliO157:H7 strain has been recommended.

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 <5 years old who were hospitalized for gastroenteritis in Fars hospitals in Iran were collected and then enriched in Escherichia coli (. E. coli) broth and modified tryptone 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: stx1, stx2, eaeA, hly has been analyzed. Results: E. coli O157:H7 was detected in 7 (1.14%) stool specimens. A significant difference was seen between detection rate 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%) the stx1 and eaeA genes were seen and also all isolated bacteria had resistance to penicillin, ampicillin and erythromycin antibiotics. Conclusions: We found that 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 of these bacteria in clinical laboratory, further and completed studies on diagnosis and genotyping of this E. coli O157:H7 strain has been recommended.

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.