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Background and Objective:Acinetobacter is a genus of non-fermenting Gram-negative cocci or coccobacilli, which have low nutritional requirements for growth and can survive for a long time in adverse conditions, on dry surfaces, and also in aqueous environments. The importance of the members of Acinetobacter genus as pathogens involved in nosocomial infections, is increasing. Acinetobacter baumannii is the most common species involved in a broad spectrum of nosocomial infections, including pneumonia, bacteremia, surgical wound infections, urinary tract infections, and meningitis. In this study, enterobacterial repetitive intergenic consensus sequence-based PCR (ERIC-PCR) technique was used for analysis and molecular typing of Acinetobacter strains, which has high discrimination power compared to phenotypic markers. Methods:In the present study, a total of 40 A. baumanniies strains were isolated from patients hospitalized in Tehran hospitals. After identification and confirmation of the isolates by serotyping and biochemical tests, a single colony of each isolate was cultured on liquid LB medium, and after DNA extraction, PCR was performed. After electrophoresis of PCR product, gel images were stored electronically for analysis and comparison of the isolates. Results:In this study, 40 strains of A. baumannii were analyzed by ERIC-PCR method, of which 29 strains were typed into 10 groups and 11 other strains had no PCR bands or had a band that could not be assigned to any of the above groups. Conclusion:In this study, it was found that A. baumanniie strains could be typed using repetitive sequences. This extent of polymorphism shows that ERIC-PCR is a useful method for analysis of genetic variation of A. baumannii strains. High genetic variation of A. baumannii strains may be due to wide geographical distribution of this species in Iran

Article Subject: Molecular Microbiology DOI: Background and Aims: Listeria monocytogenes, a gram positive, facultative, intracellular bacterium is the causative agent of listeriosis that is transmitted to human through raw and ready-to-eat foods. The aim of the present study was to determine dominant serovars of L. monocytogenes isolated from spontaneous abortion using phenotypic and genotypic methods. Materials and Methods: In present study, 258 clinical specimens including placental secretions, vaginal swabs and blood samples from 123 patients with abortion were selected in sterile condition then bacteriological, serological and molecular tests were conducted; dominant serotypes were identified by Multiplex PCR. Results: Out of 28 (%18.8) isolates of L. monocytogenes 21 (%17.7), 5 (%5.7) and 2 (%3.37) were isolated from placental secretions, vaginal swabs and blood respectively. Maximum and minimum isolated of bacteria related to placental secretions and vaginal swabs with 21 and 2 isolates respectively, of which 14 (%50) 1/2a, 10 (%35.7) 4b and 4 (%14.6) 2c serovars were reported for the first time. All of serovars played a key role in the spontaneous abortion as dominant and common serotypes in Iran. All of the isolates 28 (%22.76) showed hlyA gene and 24 isolates (%19.57) were positive for iap gene and compaired with control group there was significant different between the two groups (P<0.0002). Conclusion: The present study showed the isolation dominant and common serotypes of L. monocytogenes from spontaneous abortion and demonstrated that the presence of hlyA and iap were effective genes in increasing aggressive and pathogenicity. Serotypes that lacked the iap gene have less pathogenicity and influenced the pathogenesis in mice. It was also concluded that in the absence of access to molecular tests, performing PI-PLC, Congored and in vivo pathogenicity can be effective in detecting pathogenic serotypes from non-pathogenic L. monocytogenes.

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Background and Aims: Assessment of the extend role of dominant serotyprs of Listeria monocytogenes in spontaneous abortions, using isolation methods and PCR(Polymerase Change Reaction) analysis for the presence of dominant serotypes such as 1/2a, 4b. Materials and Methods: A total of 258 samples comprising placental bits, vaginal swabs and blood were collected from out of 123 patients with spontaneous abortion. Listeria monocytogenes was identified and confirmed by culture, biochemical, serological tests, API system, CAMP (Christie, Atkins, Munch and Petersen), hemolysis on sheep blood agar. PI-PLC (Phosphatidyl Inositol specific Phospholipase C) assay, followed by Multiplex PCR to detection of serotypes 1/2a and 4b. Result: Out of 258 samples, 28 isolates of Listeria monocytogenes were identified   by different methods. All of the isolates were confirmed by PCR. Our search indicated that from 123 patients, 28 of isolated (46.6%)  Listeria monocytogenes strains, 14(50%) belonged to serovar 1/2a, 10(35%) to serovar 4b and 4(14.2%) to other serovars respectively. Conclusions: Based on our study, serovars 1/2a and 4b play a key role in human spontaneous abortion. Data analysis also showed that these serovars (1/2a, 4b) are dominant serovars as causative agents of the spontaneous abortion in pregnant women.

Background and Aim: Since some sealants can control cariogenic microorganisms, therefore the evaluation of antibacterial effect of different sealants are the subject of this study. Materials and Methods: in this experimental study, the plates were divided into 5 groups.Group I control:two plates including Blood Agar with Mutans Streptococcus (SM) & the other MRS with Lactobacillus Acidophilus (LA).Group II:6 plates Blood Agar culture with two wells and inoculation of SM with addition of two fissure sealants; Clinpro 3M with fluoride &flowable composite 3M without fluoride.In group III all the steps were the same as group IIexcept that in which fissure sealants used were Conseal F with flouride& Eco-s without fluoride.In groups IV & V all the steps were the same as groups II & III respectively except that MRS culture media with inoculation of Lactobacillus Acidophilus was used.The diameter of the growth inhibition halo (zone of inhibition) was measured using calipers. The experiment was repeated for three consecutive days with 26 plates and the results were recorded every 48 hours.The data were analyzed using Two-way ANOVA Results: The diameter of growth inhibition halo for Clinpro 3M in the medium where Streptococcus mutans was cultured was 27/29+ 3/59mm&where Lactobacillus Acidophilus was cultured was 12/37+ 1/46mm which differed from other three materials significantly. (p<0.000) Conclution: It seems, Clinpro 3M had the most inhibitory effect on Streptococcus mutans and , Lactobacillus acidophilus growth.

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