ABSTRACT
Background: Human group A rotaviruses are the most common cause of severe diarrhea among children <5 years of age worldwide. Rotaviruses are widely present in environmental water. The aim of this study was to detect the human group A rotaviruses in urban sewage, hospital sewage and river water samples in Alborz province using ELISA method
Materials and methods: This cross-sectional study was carried out on 76 samples collected from both influent and effluent water of 4 sewage treatment systems, hospital sewage, Karaj and Baraghan rivers in Alborz province. All samples were concentrated using pellet method. Afterwards, human group A rotaviruses were detected using ELISA method
Results: In total, rotaviruses were identified in 6 samples [7.89 percent] using ELISA method. Three positive samples [50 percent] were related to the raw sewage influent and three positive samples [50 percent] were related to the Karaj river. The frequency of rotavirus detection in summer, autumn and winter was 1 sample [16.66 percent], 3 samples [50 percent] and 2 samples [33.33 percent], respectively
Conclusion: This study showed the contamination of environmental water by human group A rotaviruses. Therefore, it is necessary to constantly monitor sewage treatment systems and river water for detecting rotaviruses
ABSTRACT
Background: Staphylococcus aureus is one of the most common nosocomial and community acquired pathogens. The bacterium has different virulence factors and provides aggressive conditions to the host with secretion of the toxins such as super antigenic enterotoxins. Staphylococcal enterotoxin A and B [SEA,SEB] have the most severe toxic effect among these toxins. The aim of this study was to determine the frequency of A and B enterotoxin genes in Staphylococcus aureus isolated from skin infections in Tehran Razi hospital
Materials and methods: A total of 65 isolates of Staphylococcus aureus from skin samples were collected and confirmed with phenotypic methods and checked by Polymerase Chain Reaction [PCR] using species specific primers. Then the frequency of the sea and seb genes were detected with PCR using specific primers
Results: The PCR results showed that 86.20 % of Staphylococcus aureus isolates carried the sea gene and the frequency of seb gene in the tested isolates was 15.40 %
Conclusion: According to the importance of Staphylococcus aureus enterotoxins and their role in the development and exacerbation of the Staphylococcal diseases, the presence and expression of the corresponding genes in clinical isolates must be considered in management of the diseases
Subject(s)
Staphylococcal Infections , Staphylococcal Skin Infections , Enterotoxins , Polymerase Chain Reaction , Disease ManagementABSTRACT
Clostridium tetani or Nicolaier's bacillus is an obligatory anaerobic, Gram-positive, movable with terminal or sub terminal spore. The chromosome of C. tetanicontains 2,799,250 bp with a G+C content of 28.6%. The aim of this study was identification and genomic fingerprinting of the vaccine strain of C. tetani. The vaccine strain of C. tetani was provided by Razi Vaccine and Serum Research Institute. The seeds were inoculated into Columbia blood agar and grown for 72 h and transferred to the thioglycolate broth medium for further 36 h culturing. The cultures were incubated at 35[degree]C in anaerobic conditions. DNA extraction with phenol/ chloroform method was performed. After extraction, the consistency of DNA was assayed. Next, the vaccine strain was digested using pvuII enzyme and incubated at 37[degree]C for overnight. The digested DNA was gel-electrophoresed by 1% agarose for a short time. Then, the gel was studied with Gel Doc system and transferred to Hybond N+membrane using standard DNA blotting techniques. The vaccine strain of C. tetani genome was fingerprinted by RFLP technique. Our preliminary results showed no divergence exists in the vaccine strain used for the production tetanus toxoid during the periods of 1990-2011. Observation suggests that there is lack of significant changes in RFLP genomic fingerprinting profile of the vaccine strain. Therefore, this strain did not lose its efficiency in tetanus vaccine production. RFLP analysis is worthwhile in investigating the nature of the vaccine strain C. tetani
ABSTRACT
Salmonella enterica serovar Enteritidis which involves poultry is transmitted by food. The aim of this survey was to optimize PCR method in order to detect Salmonella enteritidis in poultry products. In this basic research, 80 samples [40 broiler meat and 40 egg samples] were obtained from distribution centers in Karaj and suburb. Following the DNA extraction of the samples, PCR was optimized and performed using standard strain of Salmonella enteritidis [RTCC1621] as positive control and primers against the flagella coding sequence of Salmonella Enteritidis genome. The analysis of the PCR products by agarose gel electrophoresis indicated the amplification of 250 bp segments in 16 out of 40 [40%] broiler meat and 9 out of 40 [23%] egg samples. The sensitivity of the PCR at the DNA level was found to be 1pg and the specificity of the PCR was determined using 6 other entric Gram negative bacteria and found to be positive only for Salmonella enteritidis. This study confirmed that PCR provides sensitive, specific and rapid approach for detection of Salmonella enteritidis in food samples