Search

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: 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: Attention has largely been focused on appearance of multiple drug resistance enterococci in the last 20 years. One of the methods to overcome this problem is to combine different antibiotics in order to increase antimicrobial activity and reduce toxicity. The combination of fluor quinolones with other antibiotics has been widely investigated. The aim of this study was to investigate the synergistic effect of ciprofloxacin in several antibiotics Beta-lactam (piperacillin, ceftazidime and imipenem) on isolated enterococci. Materials and Methods: In this cross sectional study, 67 Streptococci strains were isolated from clinical samples from March to September 2012. The serial broth dilution method in test tubes was used for the MIC, and the check board Format was used for the synergistic effect of ciprofloxacin with Beta-lactam antibiotics. The synergistic effect was determined with four- fold reduction of initial MIC. Results: Totally, 67 strains of Streptococci were used, in which 50 strains (74.6%) were enterococci, 6(9%) were group B streptococcus, 5(7.5%) were non-group A streptococci, 2 (3%) were pneumococci, and 2 were strains of alpha streptococci (3%), respectively. All results were determined by the MIC and MBC of each antibiotic individually and also in combination with ciprofloxacin. Conclusion: The effect of ciprofloxacin on other antibiotics was indifferent, and the synergistic effect was not observed. [ABSTRACT FROM AUTHOR]

Background: Septicaemia is a leading cause of morbidity and mortality of infant's and childerens espicially in first week of their life, both in developed and underdeveloped countries.The aim of this research was to study of bacterial agents causing septicaemia and to determine their antibiotic suseptibility patternes. Materials and Methods : This was a descriptive study, it was performed during eight months from October 2011 till May 2011. In total 216 blood culture samples of children suspected of septicaemia in children health centre hospital were send to the laboratory for investigation. The bacterial identification was carried out by culturing and conventional biomedical tests. The antibiotic sensitivity tests were performed by disk diffusion method. These data are analyzed by SPSS and the results Expressed as relative frequencies. Results: Out of 216 tested samples 55(25.6%) were positive and 161 (74.54%) negative. The dominated bacteria was Escherichia coli (31.42%), followed by Staphylococcus aureus (22.86 %), Klebsiella pneumonia (20%)), Staphylococcus epidermidis (14.28%), Streptococcus pneumonia (2.86%), Salmonella typhi (2.86%), Enterobacter cloacae (2.86%) and Stenotrophomonas maltophilia (2.86%). In general gram-negative bacteria were isolated more than gram-positive. Staphylococcus bacteria were more resistant to antibiotics than other isolated bacteria, and were 100% resistant to penicillin. The enterobacteriaceae were more sensitive to norfloxacin, amikacin, tobramycin, and they were 100% resistant to ampicillin. Conclusion: The results obtained in this study showed that gram-negative bacteria are more responsible in septicaemia in children ward, and norfloxacin is the more effective antibiotic in comparison with others. [ABSTRACT FROM AUTHOR]