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Background and Objective: Yersinia is a gram-negative bacillus that cause diarrhea through consumption of contaminated food and water. This study was performed to identify the atypical Yersinia virulence markers isolated from children with diarrhea. Methods: This descriptive cross -sectional study was done on 384 fecal samples of 0- 14 years old children admitted at children medical center from August 2011 to August of 2012. Fecal samples, for the enrichment, after 21 days of incubation in alkaline buffer with pH=7.2 at 4degree C, on days 7, 14 and 21 samples were cultured on CIN agar and Mac agar and then confirm the differentiation atypical Yersinia from other typical Yersinia species from fermentation of different sugars. Isolates were tested for marker of virulence including calcium dependence, auto agglutination, Congo red uptake and binding of crystal violet. Results: Out of 384 stool samples, 4 (1.04%) were infected with Yersinia (Yersinia frederikseni, Yersinia kristensenii and Yersinia enterocolitica). Out of these three, only two samples in association was positive with virulence markers. Conclusion: Phenotypic markers can be used to study the properties of phenotypic strains of Yersinia.

Background and Objective: Probiotics are beneficial organisms therapeutic within microbial flora. Shigella, Escherichia coli and Salmonella are the most common cause of intestinal infectious diseases that lead to morbidity and mortality in infant and children worldwide. The aim of this study was to evaluate anti-microbial activity of Lactobacillus acidophillus and Lactobacillus ruteri against entero-pathoges by in vitro and in vivo methods. Methods: In this experimental study, the therapeutic effect of the lactobacillus acidophilus ATCC 4356 and ruteri ATCC 23272 against Shigella sonnei ATCC 9290, Escherichia coli ATCC 25922 and Salmonella enterica BAA-708 were evaluated by in vitro (spot agar) and in vivo (BALB/c mice) methods. Weight improvment and survival rate in mice were recorded. Results: Lactobacillus acidophillus and ruteri had protective and therapeutic effect against diarrhea caused by pathogenic bacteria. Probiotics reduced the weight, colonization of pathogens and increased the survival rate of animals (P

Background and Objective: Yersinia enterocolitica is a worldwide pathogen belong to genus Yersinia. The association between acute childhood diarrhea and other diseases caused by Yersinia enterocolitica has been established by several researchers. Due to the lack of sufficient information on other pathogenic Yersinia species, this study was done to determine the prevalence and the pattern of antibiotic susceptibility of atypical Yersinia spp isolated from children, less than 14 years old. Methods: This descriptive cross - sectional study was carried on 384 children with diarrhea whom referred to the Tehran children medical center, Tehran, Iran during August 2011 to August 2012. 384 fecal specimens of children were transferd to the laboratory and cold enrichment in alkaline buffer with pH of 7.2 for 21 days. The samples were cultured in Cefsulodin-Irgasan-Novobiocin Agar (CIN) differential media in 7, 14, and 21 days. The identification of Yersinia species were carried out by conventional procedure. Antibiotic susceptibility test to Ciprofloxacin, Co-trimoxazole, Tetracycline, Chloramphenicol, Erythromycin, Ampicillin, Gentamicin, Penicillin were determined by standard disk diffusion method. Results: Out of 384 fecal samples, 3 (0.7%) were infected with Yersinia. Three species of Yersinia were Y.enterocolitica, Y.Kristensenii and Y.frederiksenii. All three strains were sensitive to Cotrimoxazole, Tetracycline, Chloramphenicol, Ciprofloxacin and Gentamicin. Conclusion: This study showed that atypical Yersinia play important role in diarrhea. Therefore, more attention should be noticed to atypical Yersinia species in addition to Yersinia enterocolitica.

Background and Objective: Gastroenteritis due to Salmonella is common in human and considered as a global dilemma of public health. This study was done to determine the Pattern of serotyping and antibiotic resistance of Salmonella in children with diarrhea in Iran. Methods: In this laboratory study, 306 stool samples were collected from children with diarrhea in public health centers in Robat-karim, Tehran province, Iran. The specimens were enriched in Selenite F medium and then cultured on Hekton agar. The identification of Salmonella was carried out by conventional method and antimicrobial susceptibility testing was performed according to CLSI procedures. Results: Out of 306 stool samples, 7.2 % were identified as Salmonella species, as follow: 7 Salmonella typhi, 6 Salmonella paratyphi B, 3 Salmonella paratyphi C, 2 Salmonella paratyphi A and 4 samples were not identifiable. There was a significant relation between presence of WBC in fecal and salmonellosis (P

Background and Objective: Klebsiella species are gram-negative bacteria with positive voges proskauer (VP) reaction. Klebsiella species are found as commensal in human digestive and respiratory system. This group of organisms can create a serious health hazards in hospitalized patients, and their ability to drug resistance is a major health problems. This study was done to evaluate the efficacy of Ciprofloxacin, Ceftizoxims and Carbenicillin on Klebsiella species isolated from hospital specimens. Materials and Methods: In this laboratory study, 1200 clinical samples were isolated from patients in Imam Khomeini hospital, Tehran, Iran. The identification Klebsiella species were carried out according to conventional biochemical tests. The minimum inhibitory concentration (MIC) of carbenicillin, ceftizoxime, and ciprofloxacin antibiotics were determined using Macrodilution broth test. Results: Out of 1200 isolated samples, 25% were identified as Klebsiella species. 73% of identified Klebsiella were obtained from urine samples. Klebsiella.peumoniae with rate of 94% was the most abundant among other species. The results of MIC and minimum bactericidal concentration by using standard microdilution method showed drug resistance range of 16-1024 μg/ml, 4-256 μg/ml and 0.25-16 μg/ml for carbenicillin, ceftizoxime, and ciprofloxacin, respectivley. In general, 94%, 6% and 1% of species were resistance to carbenicillin, ceftizoxime and ciprofloxacin, respectively. Conclusion: Ciprofloxacin and Ceftizoxime are suitable for the treatment of infections due to Klebsiella species.

Abstract Background and objectives: Helicobacter pylori is a helical gram negative bacterium with polar flagella, discovered by Warren and Marshall in 1983. Helicobacter pylori exist in the stomach mucus tissue of less than 20% of people under 30 years old, but this amount would increase up to 40% and 60% in 60- year- old people. The aim of this study was to compare three methods of culture media, direct slide staining and the urease test for the rapid diagnosis of bacterium in case of peptic or duodenal ulcer. Material and Methods: In This descriptive study, duplicate biopsy specimens were taken from 82 clients referring to four different Hospitals .In endoscopy room of the Hospitals, a rapid urease test were carried out on one of duplicate specimens for the presence or non-presence of Helicobacter pylori. In order to see the Helicobacter pylori in the tissues, three slides using foushin, giemsa, and gram staining were prepared from the second specimens. Then, the specimens were incubated into selective culture media and incubated for 4-6 days in micoraerophilic condition. Results: Of 82 tested specimens 70(85.5%) and 66(80.5%) are identified as Helicobacter pylori by positive urease and culture medium, respectively. The frequency of foushin, giemsa, and gram staining are 67 (81.7%), 66 (80.5%), and 61 (74.4%), respectively. The foushin staining is the best with 100% sensitivity among the other methods. Conclusion: Based on difference between proportions, There is no significant difference between staining methods (foshin, giemsa, gram staining) and culture media in all cases. Key words: Helicobacter pylori, microscopic methods, urease test, culture media, identification

Background&Objective: Foodstuffs additives are a general term for materials that are added to the foodstuffs in order to increase durability and to improve the appearance, composition, taste and food nutritional value. Colors are classified in this group and are added to foodstuffs in order to increase their attraction. Colors may cause illness such as allergy, rash and hyper activation in children and also they may debilitate the Immune system, Anaphylaxis reactions may also occur and they may have cancerous effect. The aim of this survey was to analyze status of added colors to the dried sweets which are produced in south of Tehran city. Materials & Methods: 191 samples of dried sweets were randomly collected and analyzed from south of Tehran areas. First, the samples were de-colored by Clorhidric Acid, and then were analyzed after refining by Thin Layer Chromatography (T.L.C) method. Samples were identified by taking Retention Factor (RF values) into consideration. Results: 93.2 percent from the total samples contained colors. Among chromatic samples, 42 samples (22%) out the total samples, contained artificial, non-edible colors and 96 samples (50.3%) from the total samples contained artificial and edible colors (for Industrial Producers) and 40 samples (21%), contained natural colors. Sunset yellow color was detected more than other added colors in sweets. Conclusion: Low costs, stability, PH, purity, and environmental conditions, motivate the producers for high utilization of edible colors without considering their possible hazards and/or their edible quality aspects. It is suggested that, based on the findings of this study and high consumption of colors.