Iranian Journal of Infectious Diseases and Tropical Medicine
Year:2010 | Volume:15 | Issue:49|Papers Count:14

Background and objective: Rotaviruses are the most important cause of severe viral gastroenteritis and dehydration diarrhea in children under five years old worldwide. This study conducted to determine genotypes of protein 7 human rotaviruses with Nested RT- PCR among children hospitalized in Marvdasht During 2007 to 2008.Material and methods: In this study, 141 stool samples of under 5 years old hospitalized children with severe diarrhea were collected from Motahary hospital in Marvdasht. At first group A Rotaviruses were distinguished by Enzyme Immunoassay (EIA) and then, the genotypes of positive samples were determined by using 9 specific primers by Nested RT-PCR method.Results: Out of total collected samples, 40 were positive by EIA. The frequency of G1, G2 and G4 Genotypes were 5.0%, 12.5% and 10.0% respectively. G3, G8 and G9 were detected in none of specimens. The frequency of mixed and non-typeable genotypes was determind 60% and "12.5% respectively.Conclusions: Frequency of mixed genotypes indicates severe infection because of low sanitation or transmission of recombinant strains from animal to humans. Also, the noticeable frequency of non-typeable genotypes indicates the necessity of using other primers for identification of unusual genotypes.

Antiretroviral drugs have improved the course of human immunodeficiency virus (HIV) infection.The cornerstone of these treatments is selection of potent and tolerable regimens to which the patient can adhere and suppress the HIV replication without side effects and emergence of drug resistant strains. Several compounds have been used for the treatment of HIV infections. Drug combinations are aimed to obtaining synergism between the compounds, while reducing the likelihood of drug resistance development. In This paper we reveiwed articles about the efficacy and safety of antiretroviral drugs combination regimens. The results of this survey demonstrated superior virologic, immunologic and morphologic effects of tenofovir-emtricitabine regimen compared to other therapeutic regimens.

Background and objectives: In addition to being a member of the normal gut flora of nearly all animal and human, Enterococci has the ability to cause a wide range of nosocomial infections.According to transfer of resistant genes between bacteria and human, natural reservoir can affect the distribution of resistant species. The aim of the present study was to investigate and identify the prevalence of VRE within isolated Enterococci which was separated from number of Tehran Livestock husbandry unites.Material and methods: 165 isolates of Enterococci were selected on Membrane Filter Enterococcus Selective Agar medium, supplemented with 2, 4 and 8 mg/ml vancomycin. and identified at the species level by the common biochemical tests and specific genus and species primers. The Antibiotic susceptibility was determined by disc diffusion method for 6 antibiotics.MIC of vancomycin was also done using broth micro-dilution assay by CLSI recommendations.Results: Results showed that 86, 57 and 22 isolates were E. faecium, E. faecalis and E. gallinarum respectively. 35, 27, 24, 15, 39, 39 of the isolates were resistant to vancomycin, tetracycline, gentamycin, chloramphenicol, ciprofloxacin and erythromycin respectively. MIC test of the 65 and 30% of the isolates were ³256 mg/ml and ³128 mg/ml respectively.Conclusion: Although diversity of VRE isolates were restricted to 3 species, but E. faecium had high resistance to broad range of Antibiotics. Results of this study showed that more attention must be paid to the important role of livestock samples as a reservoir of resistance elements. Husbandry precise consideration must be given to sanitary and food industries.

Background and objective: Due to the major diffusion of methicillin resistant Staphylococcus aureus (MRSA) strains in hospital settings, prevention and control strategies are receiving increased attention. Phenotypic methods for detection of MRSA have been compared with the gold standard which, as of now, is by the detection of mecA gene by polymerase chain reaction (PCR).Material and methods: The study was conducted from October 2008 to August 2009 and included 350 staphylococci isolates. All Staphylococcus aureus isolates were tested for methicillin resistance using oxacillin disk diffusion and MIC and presence of mecA gene by PCR. Antibiotic resistance of MRSA isolates were accomplished according to the CLSI guidelines.Results: Out of 350 samples 150 Staphylococcus aureus isolates were obtained and MRSA was identified in 68 (45%) samples. All of the MRSA isolates were resistant to penicillin and amikacin and resistance percents among MRSA isolates to kanamycin, ciprofloxacin, tobramycin, erythromycin, gentamicin, tetracycline, clindamycin and co-trimoxazole were higher than 80%. The MIC results for 25 (37%) and 40 (59%) of MRSA isolates were ³512 mg/ml and ³256 mg/ml respectively. The PCR method indicated the presence of mecA gene in 64 (95%) of MRSA isolates.Conclusion: Prevalence of high level methicillin resistance among MRSA isolates is quite high and co-resistance to several antibiotics was detected during the present study. Active surveillance should be considered for the prevention of an outbreak of this type of MRSA in hospital settings.PCR facilitates the rapid detection of MRSA and has the potential to contribute to preventing spread, but should continue to be used in conjunction with culture and drug resistance tests.

Background and objective: Surveillance is collecting, analysis, interpretation of data and distribution of information on a health event. This information can be used by health authorities for planning, implementation and assessment of health programs and activities. This study aimed to assess knowledge and practice of general practitioners (GPs) about Surveillance System in under coverage area of Shahid Beheshti Medical Sciences University, Tehran, Iran.Materials and methods: Through a cross sectional health system research 672 GPs who were working in their private offices in north and west of Tehran in 2008-9, randomly selected. These GPs were selected using sampling framework of private sector physicians of sub secretary for treatment, disease control unit and north, west and Shemiranat health centers. Data gathering has done using questionnaire, interview and inspection.Results: Among 672 participated GPs, 320 (47.6%) during their lifetime practice and 124 (18.5%) during past year reported averagely 3.6 and totally 450 cases. Fifty five percent of GPs were aware of appropriate time of disease report. More cases were reported by GPs used related posters in their office, who had more knowledge and have been working in health sector.Conclusion: Private sector GPs participation in reporting targeted diseases is in low level.Limited knowledge, inappropriate broadcasting, follow-up, feedback and distribution of collected data were introduced as influencing factors.

Background and Objectives: The most important goal of Blood Transfusion Organization is to provide and supply safe and sufficient blood. The awareness of blood transmitted infections prevalence in blood donors that in emergency conditions for example earthquake blood were donated, be could indicator effectiveness of blood donors selection methods and generally education programs of Blood Transfusion Organization. This study was carried out to determine and comparison demographic characteristics, donation type and prevalence of blood transmitted viral infections in Qom blood donors during 48 hours after Barn earthquake (5-6 Daymah, 1382) and other days of 1382 year.Materials and methods: In this Cross-sectional Retrospective study, the comprehensive data bank of Iranian Blood Transfusion Organization (IBTO) was used to collect the number of blood donors, donation type (first-time, repeat and regular), demographic characteristics (sex, age, marriage status, occupation and education level) and confirmated results of HBs-Ag, HCV-Ab and HIV-Ab tests of Qom blood donors that blood had donated during 1382 year (according to Iranian calendar). Data were analyzed by applying SPSS software and Chi-square statistical test.Results: Prevalence of HBV, HCV and HIV infections in Qom blood donors during 1382 year subtraction fifth and sixth days of Daymah the same year (26-27 December, 2003) were 1.06, 0.28 and 0.006 percent respectively; whereas, prevalence of HBV infection in blood donors of abovementioned two-days was 0.58 percent and none of blood donors weren't infected with HIV and HCV. The number of first-time and regular blood donors, married and self-employed during 48 hours after Barn earthquake with significant statistical difference (P<0.05) were more in comparison with other days of 1382 year.

Background and Objectives: Imipenem use as therapeutic for infections associated with drug resistant gram negative bacteria harboring ESBL and Amp C genes. Resistance to imipenem cause with emerged metallo-b-lactamases.Considering to the importance role of Pseudomonas aeruginosa in nosocomial infection, the aim of the study was to determine the imipenem resistance and presence of metallo-b-lactamases (MBLs) in b-lactamase producing clinical isolates of P.aeruginosa.Materials and methods: sixty P.aeruginosa species isolate from bum patient in Ghotbodin hospital of Shiraz. Resistance to cefotaxime, ceftazidime and imipenem was determined by disk diffusion method. Disk diffusion method was used for determination presence of metallo-b- lactamases. The Disks containing 10Ilg imipenem and 10llg imipenem+10 ml EDTA 0.5 M were used. The increase of inhibition zone ³7mm of imipenem tested in combination with EDTA versus imipenem alone was considered positive for MBL. Resistances to seven different antibiotics were determined.Results: From total of 60 b -lactamase producing isolates of P.aeruginosa, 18 isolates were found to be resistant to Imipenem, that five isolates were determined to be MBL producers by phenotypic method. All producing MBLs isolates were resistance more than to eight antibiotics from different classes simultaneously.Conclusion: According to the presence of metallo b lactamases in bacterial strain in the region, also increasing use carbapenems in treatment of infections by producing MBLs and multi drug resistance isolates in our country is not unexpected.

Background and objective: Pertussis is a highly communicable, vaccine-preventable disease.The use of vaccines has reduced the disease but hasn't eliminated the circulation of Bordetella pertussis.In this study we determined the seroprevalence of antibodies against B. pertussis in different age groups in Tehran.Materials and methods: Plasma samples of 1101 subjects between ages of 8 months and 20 years were tested for the presence of pertussis toxin (PT), filamentous hemagglutinin (FHA) and different lipopolysaccharides (LPS) antibodies by ELISA. All cases vaccinated at least three times with DTwP in the first year of life, followed by two boosters at the age of 18 months and 4-6 years.Results: The overall prevalence of pertussis antibodies was 48% and the mean antibody level was 44±47.7 u/ml. Over half (53.1%) of the children aged 8 months to 6 years were negative for pertussis antibodies. Pertussis antibodies rates and levels were significantly different between age groups and their significant elevations were observed with increasing age.Conclusion: Our study showed that up to half of the vaccinated children lacked an antibody response to vaccine, so using a more immunogenic ally effective vaccine to ensure sufficient immunity is essential. Also we showed that B. pertussis infection is on the rise in Iranian adolescents and young adults. Booster vaccination of this age group appears to be the most logical approach to disease prevention in adolescents and control the circulation of the organism.

Background and objective: E. coli Isolation rate by culture-method will be reduced if animals take antibiotics before sampling. This study aimed to setup, optimize and introduce a sensitive and specific PCR detection method for identification of E. coli DNA in clinical samples.Materials and methods: stx2A gene was selected as a specific target sequence. This primer pair amplifies 556 bp of this target gene. E. coli 0157H7 was used as a standard organism for optimization experiments. Phenol – Chloroform method was used for DNA extraction. Amplified product was detected by 1% gel agarose electrophoresis, stained by ethidiome bromide.Results: Provided data confirmed amplification of expected product. Specificity test proved no cross reaction with tested organisms. Sensitivity test detected 500fg E.coli DNA as a final detection limit.Conclusion: Optimized experiment confirming applied PCR protocols is quite fast with high sensitivity and specificity performing in less than three hours.Application of this test to the clinical laboratories can help to rapid diagnosis of the E.coli in samples.

Background and objective: Shigelosis is one of five important infectious diseases. Infection by different species of Shigella (gram-negative bacterium) results in dysentery, an acute inflammatory disease of the colon. Many attempts carried out for produce an efficient vaccine aginst shigella and there are more hope to immunogenic elements of shigella such as invasive plasmid antigen (IpaB, IpaC).Materials and methods: ipaB gene was extracted and amplificated as a template. Then the PCR product was cloned into pGEM-T vector and then subclone into PET22b (+). Finally plasmid was extracted from transformed Escherichia coli (TOPIO strain) and subclon confirmed by enzyme digestion as well as, nested PCR.Results: ipaB gene detected in all strains of shigella; PCR and nested PCR and enzyme digestion confirmed ipaB gene cloned into PET22b (+).Conclusion: According to detection of ipaB gene in all shigella strain, we could use these primers in clinical diagnosis. We cloned ipaB gene of S. dysenteriae successfully. Recombinant plasmid was confirmed. It prepare for future studies such as expression of this protein and assay of immunogenicity, then present this recombinant plasmid as a candid for recombinant vaccine of shigellosis.