ABSTRACT
BACKGROUND: Infections due to Staphylococcus aureus, a nosocomial and community-acquired pathogen, is a major public health problem. Wide range of diseases caused by S. aureus from mild infections of the skin and soft tissue to life threatening diseases which is due to having several virulence factors such as enzymes, toxins and also enterotoxins. Enterotoxin A (SEA) and enterotoxin B (SEB) are superantigens and gastrointestinal toxins causing food poisoning. The sea and seb genes encode SEA and SEB, respectively. The goal of this study was determine the prevalence of sea and seb genes in S. aureus isolated from patients and healthy carriers in Gorgan city, north of Iran. MATERIALS AND METHODS: 170 isolates of S. aureus (95 from patients and 75 healthy carriers) were collected during 1 year. After identification and purification, DNA extraction was done by phenol - chloroform method. Amplification of sea and seb genes was done by specific primers and polymerase chain reaction method. RESULTS: Among the 170 isolates of S. aureus, 60.6% and 27.1% contained sea and seb genes, respectively. The frequencies of isolates containing sea and seb genes were 58.8% and 61.3%, respectively, in methicillin-resistant Staphylococcus aureus (MRSA) isolates and 23.5% and 28.6%, respectively, in methicillin-sensitive Staphylococcus aureus (MSSA) isolates which were not statistically significant. The frequency of these genes was not related to age, sex and source of isolation in the patients. CONCLUSION: This study showed that a high proportion of S. aureus isolates carried sea gene, whereas the frequency of seb gene in this region was predictable.
Subject(s)
Carrier State/microbiology , Enterotoxins/genetics , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , Adolescent , Adult , DNA, Bacterial/genetics , Female , Humans , Iran , Male , Middle Aged , Polymerase Chain Reaction , Prevalence , Staphylococcus aureus/isolation & purification , Virulence Factors/genetics , Young AdultABSTRACT
OBJECTIVE: Shigella is an important etiological agent for diarrhea and especially dysentery. Shigellosis is an intestinal infection that is a major public health problem in many developing countries. The aim of this study was to evaluate the prevalence of Shigella and its various species in diarrheal samples in Gorgan located in the north of Iran. MATERIALS AND METHODS: Between January-December 2005, the epidemiology of Shigella- associated diarrhea was studied among 634 patients in Gorgan. The diarrheal samples accompanied with a questionnaire, which contained the demographic and main symptoms of the patients, were transported to the laboratory and inoculated in different culture media. Colonies suspected to be of Shigella were detected using differential biochemical tests and subsequently, the serotype of Shigella was defined using antisera. RESULTS: Shigella was isolated from 56/634 diarrheal samples) (8.8%) of which S. sonnei was the predominant species (55%). Occurrence of Shigella was highest in the 2-5 years' age group (70.9%) and highest in summer (73.2%) with the most frequent clinical manifestation being abdominal pain (67.8%). The prevalence of Shigella in males and females was 8 and 9.8% respectively, but this difference was not statistically significant. CONCLUSION: It has been shown that Shigella sonnei is the most common Shigella serogroup among 2-5 year-old children in Gorgan. It is therefore suggested that hygienic training be given to childcare attendants and the children themselves.
