[Standardization of the molecular method for detection of the ent D in staphylococcus aureus isolated from human infections: and sequence determination]

Staphylococcal enterotoxin D as a supper antigen is produced by infected samples of human and animal sources. The aim of this study was to standardize the detection methods for the Staphylococcus strain producing enterotoxin D. A PCR method was set up for detection of enterotoxin D gene [ent D] in Staphylococcus aureus samplesisolated from the human subjects [310 strains isolated from clinical samples]. The specific PCR-product [a band about 700 bp] was purified and sent off for DNA sequencing. Blast analysis showed a 99% identity with the standard gene sequence from Genebank. The ability to produce enterotoxin D by all strains carrying ent D was analyzed by using an ELISA kit. The results of this study show that the PCR method has been well set up. There were two PCR products obtained by the primer pair, one at 700 bp and another at 1400 bp. Both bands were gel purified and sent for DNA sequencing. The results, based on the alignment with the standard ent D sequences from GenBank, suggest that ent D is contained within the 700-bp product. Production of the entrotoxin D in the positive strains was confirmed by ELISA. Based on the available information, coagulase positive Staphylococcus aureus strains are recorded in clinical samples. However, there is no routine method available to analyze the ability of the bacterial strains for producingtoxins including enterotoxin D. This study represents a simple, fast, and standard method for verification of the bacteria enterotoxin D and the strains producing it

effects of vaccination against meningococcal meningitis in Islamic Republic of Iran military forces during the years 1981 to 2009

Meningococcal meningitis is usually seen in overpopulated areas such as military barracks and causes high levels of mortality and morbidity. The aim of this study is to determine the role of vaccination as an interventional method in preventing this infection during 1981 to 2009 in Islamic Republic of Iran Military Forces. In a cross-sectional, the related documents in three other projects, including the mortality rate in high risk populations, intervention by vaccination and its efficiency in the soldiers, were surveyed along with the epidemiological evidences found using advanced laboratory method. The results indicated that the good vaccination has succeeded in protecting at risk groups with high levels of immunity. However, the vaccination accompanied with improved management of the patients resulted in a decrease in the mortality rate less than 0.1% by the end of 2008. Most of the patients who were at risk of meningitis were retired personals and their families. In addition, 35% of bacterial meningitis was due to Streptococcus pneumoniae. The results of this research indicated that the prevalence of mortality decreased from 106 cases in 2001 to nearly zero in 2009 which is due to control of meningococcal meningitis by vaccination and shows its significant impact on infection reduction

Specific PCR assay for rapid and direct detection of Neisseria meningitidis in cerebrospinal fluid specimens

Neisseria meninigitidis is one of the most frequently encountered microorganisms associated with central nervous system infections. The aim of this study was to evaluate a PCR-based assay for specific and rapid detection of N. meninigitidis in CSF specimens. Since April 2002 to July 2006, 130 CSF specimens were collected from patients suspected of having baterial meningitis. Bacterial isolation and identification was carried out according to the standard bacteriological methods. The PCR was used to amplify a 101bp fragment of capsular transport gene A [ctr A] of N. meningitidis. PCR yielded an amplified product with the expected size of 101 base pair fragment. Sensitivity test proved 500 mg of N. meningitidis DNA as the final detection limit and specificity test revealed no cross-reaction for a wide range of respiratory pathogenic organisms. The PCR assay was more sensitive than the bacterial culturing. It might be possible to apply this procedure for rapid diagnosis of meningococci in clinical samples

Advatages of rapid diagnosis of bacterial meningitis by PCR in compare with direct microscopy and culture

Acute bacterial meningitis has remained an important cause of death and neurological damages among survivors. Rapid diagnosis of bacterial meningitis is crucial for the early targeting of antimicrobial therapy. The aim of this study was to develop and apply a PCR assay for rapid diagnosis of meningitidis and to compare the results with those obtained by conventional bacteriology. We assessed 150 cerebrospinal fluid [CSF] specimens from suspected patients by PCR targeting 16S rRNA gene with specefic primers for Neisseria meningitidis, Sterptococcus pneumonia and Heamophilus influenza. All speciemns were also examined by conventional bacteriology. The rapidity of diagnosis increased when bacteriological methods were combined with PCR. Of 150 speciemens tested, 10 were positive for Neisseria meningitidis in PCR. Direct microscopy and bacterial culture found 5 and 8 cases infected with this organism respectively. PCR was more sensitive than direct microscopy and culture for detection of Neisseria meningitidis. However, direct microscopy may provide evidences for the quality of specimens and presence of other organisms in the samples. Wet- mount direct microscopy showed morphology and arrangements of the observed organisms that may be helpful in presumptive identification of certain bacteria such as gram negative bacilli and cocci. Moreover, the observed organisms may be useful in correct selection of culture media in the laboratory and prescription of appropriate therapy by physicians in a quickest time

Is cholera outbreak related to climate factors? report of seven year study from 21th March 1998-to 21th March 2004 in Iran

Cholera is a main food and water borne diseases world wide. This study was conducted to in order to find out is there any relation between Cholera outbreak and climate factors. The number of cholera infection during seven years [1998-2004] compared with the same year climate data. In addition the epidemiology of infection was surveyed in order to find out the possible link. The results of this study indicated that with decreasing or increasing from minimum or maximum range of temperature the outbreaks is dropped down sharply. The humidity around 50% is also prepared the best condition for the outbreak too. Cholera outbreaks could be related with many climate factors. Some factors including moderate temperature [25°C] and humidity increase the risk of epidemic conditions. However the rainfall above 294 mm in the rain seasons and high temperature above 49.6 in hot seasons are the major factors which could be related to cholera epidemic

Serotyping of Neisseria meningitides in conscripts with meningitis admitted to five military hospital in Tehran between September 2004 and September 2006

Meningococcal meningitis is one of the most feared disorders with high rate morbidity and mortality. There is no exact information of meningococcal meningitis incidence in military personnel. Obligate vaccination of the military with meningococcal vaccine is a strategy with the potency to provide active protection of the conscripts before being dispatched to training centers. Although sporadic cases of meningitis in conscripts occurred The aim of this study was serotyping of the bacterium; Neisseria meningitides isolated from patients with meningitis which admited to five military Hospitals. In this cross- sectional study for determination of meningococcal meningitis serotypes in conscripts submit to five military hospitals the investigation was designed and carried out from September 2003 to September 2006. In this period, 12 cerebrospinal fluids of conscripts with clinical signs and symptoms of meningitis were collected, and the laboratory tests were done. In this study enriched Thayer Martin medium and standard bacteriological methods were used. The sample without bacterial cells or PMNs were centrifuged [10000 xg for 5 min], The precipitate was cultured and direct smear was performed.Isolated bacterial strains was recognized by biochemical tests, and Neisseria meningitides strains were serotyped by specific antiserum. During the study, 12 cases of meningitis in conscripts were seen. Neisseria meningitides was isolated only from 6 patients. Serotyping analysis revealed that 5 strains belong to Serotype C and 1 strain was to serotype B. Neisseria sica was isolated from one patient. In three patients there was no bacteriological evidence. In two patients, consumption of antibiotic before lumbar puncture results to no bacterial growth, but direct smear showed gram negative diplococci. In one patient recurrent meningococcal infection has occurred. Complement components analysis revealed deficiency in C3, C4 and CH50 [the rate was below 80 mg per deciliter]. The results of this study showed that, Neisseria meningitides was isolated from six patients which are all conscripts. It is necessary to find the reasons that why vaccinated conscripts infected by Neisseria meningitides serotype C. Further analysis showed that, five patients had complement deficiency and further research is necessary. However, 6 Neisseria meningitides strains were isolated from meningococcal vaccinated conscripts around the country [Tehran, Shiraz, Yazd and Oslavieh] in the period of study. Based on the findings of this study, effectiveness of the vaccine was desirable and the disease had been controlled in this population group. Because of complements deficiency in patients with meningococcal meningitis, other preventing methods for eradication of disease are necessary