Tehran University Medical Journal

Background: Determining the etiologic causes of septic arthritis is of the most importance. Goal of this study was to investigate presence of staphylococcal enterotoxins A, B, C and Toxic Shock Staphylococcal toxin-1 in the synovial fluid of patients with arthritis.

Methods: This cross-sectional study was performed in the Pediatric and Orthopedic Wards of Hazrat Rasoul Hospital in Tehran, Iran during 2008- 2010. Gram stains, conventional cultures, direct detection of soluble bacterial antigens were used to detect H. influenza, S. pneumonia, group B streptococci, and N. meningitidis while Latex particle agglutination test was used for staphylococcal supper antigens (by enzyme immunoassays) upon synovial fluid tapping of 62 individuals (5 mo to 16 yrs, mean=113.8 yrs). P<0.05 was considered statistically significant.

Results: Positive SF cultures (n=11): 5 positive cases of S. aureus 5 S. pneumonia 1 H. influenza, and 1 Klebsiella. Positive gram stains: 10% and positive LPA: 4%. Staphylococcal arthritis was diagnosed in 7 (39%) cases upon positive culture or positive gram stain. The most common type was TSST-1 (47%) and the least common was enterotoxin B (18%). Isolation of S. aureus (positive culture) was correlated to presence of enterotoxin A in synovial fluid but not to enterotoxins B, C or TSST-1.

Conclusion: Staph. aureus had a prominent role in arthritis. 47% of cases with negative culture for S. aureus had at least one type of staphylococcal super antigens in the synovial fluid. Searching for antigens of usual organisms or staphylococcal supper antigens could be helpful for diagnosis and

Background: Staphylococcal superantigens (SAg&aposs) may have some role in otitis media with effusion (OME). The aim of this study was the search of staphylococcal SAg&aposs in middle ear effusion of children with OME. 
Methods: This cross sectional-analytic study was done in ENT & pediatric wards upon 64 children with otitis media with effusion (OME) between 1-15 years, (mean age=7.42+4 years) of Rasoul Akram University Hospital, Tehran, Iran in 2009-2011. Fifty six percent (36) of cases were male, 43.8% (28) were female. Staphylococcal SAg&aposs Toxic Shock Syndrome Toxin-1 (TSST-1), Staphylococcal enterotoxin A, B, C, D (Enzyme immune assay, AB Cam, USA) were detected in middle ear effusion samples after conventional culture.
Results: None type of SAg&aposs found in 39% of OME cases, enterotoxin B found in: 22% enterotoxin A: 17%, enterotoxin C: 15.6%, enterotoxin D: 12.5%, Toxic Shock Syndrome Toxin-1 (TSST-1): 7.8% Mean age of cases with positive TSST-1, enterotoxin A, B, C, and D was: 1, 5, 8.6, 9.6 and 9.6 years respectively. Positive TSST had no agreement with positive enterotoxin A and C but had weak agreement with type B and D. Mean age of cases with positive TSST was one years which had significant difference with (7.9 years) in cases with negative TSST test (P<0.0001).
Conclusion: At least one or more type of staphylococcal toxins had found in middle ear effusion of 70% of OME cases with negative culture for Staphylococcus aureus. Even in culture negative cases, staphylococcal toxins might have some immunologic role in middle ear effusion forming. Finding the SAg&aposs (at least one type) are important for treatment of immunosuppressive or corticosteroid in cases with resistant OME.

Background: Staphylococcus aureus is one the most common pathogens causing community-acquired infections and a major concern for public health, and the other hands antibiotic resistance is also of great concern for public health authorities also Staphylococcus aureus produce a lot of virulence factors such as variety of exoproteins included toxic shock syndrome and exfoliative toxin which causes colonization and different infections in their host. The aims of current study were to evaluate the prevalence of Toxic shock syndrome toxin 1 (TSST-1) and ETs genes in isolated S. aureus strains using polymerase chain reaction (PCR) assay. Methods: This cross-sectional study was performed on 100 methicillin-resistant staphylococcal aureus (MRSA) and 100 methicillin-sensitive staphylococcal aureus (MSSA) isolated from clinical specimens of inpatients, outpatients hospitals and nasal carriers in Hamadan University from October 2013 to August 2014. Identified species by biochemical methods were confirmed by the PCR method. Antibiotic resistance was performance by disk diffusion and the presence of TSST-1 and ETs genes was investigated using PCR. Results: Of the 100 isolates MRSA examined, the most frequent resistance was observed to ciprofloxacin (95%), followed by tetracycline (91%), erythromycin (92%), Gentamicin (90%), Rifampin (85%), trimethoprim-sulfamethoxazole (85%), clindamycin (80%) and cefoxitin (100%). Of the 100 isolates MSSA examined, the most frequent resistance was observed to erythromycin (68%), ciprofloxacin (66%), followed by tetracycline (52%), gentamicin (25%), clindamycin (46%), rifampin (45%), trimethoprim-sulfamethoxazole (66%) and cefoxitin (0%). Prevalence of TSST-1 and ETs genes were determined 13% (n=26) isolates, totally. Also the prevalence of TSST-1 was 11% (n=22) and ETs genes was 2% (n=4) isolates and none of the investigated isolates carried eta gene. Conclusion: The increasingly prevalence of MRSA and emerging its antibiotic resistance in clinical isolates can be considered a serious problem for public health. Detection of the high rate prevalence of TSST genes in current study is considered as a serious problem and existing and circle of these strains in according to colonization in community especially old people and immunocompromised patients is very serious.

Background: Staphylococcus aureus is a gram positive coccus which is able to cause different kinds of infection in certain condition. The function of this bacteria is to provide the conditions for the invasion of it to the host with the secretion of different sorts of toxins such as Staphylococcus aureus enterotoxin, including important virulence factors that super antigens are all factors digestive inconvenience. Staphylococcus aureus enterotoxin-secreting toxins such conditions provides invasion of host genes. There are different types of SE, but type A enterotoxin (SEA) and type B enterotoxin (SEB) are the most important types. Therefore, in this study, the prevalence of Staphylococcus aureus toxin-producing enterotoxin genes (SEB, SEA) in clinical strains isolated from patients in teaching hospitals of Shahrekord city, Iran, were studied.

Methods: This cross-sectional and descriptive study, which was conducted from May 2014 to December 2014. A hundred and ten isolates of Staphylococcus aureus from patients collected over a period of 8 months and were first identified using standard biochemical methods and laboratory. Using standard methods and laboratory tests were identified and compared with the antibiotic oxacillin minimum inhibitory concentration were determined by broth micro dilution, and then they were assessed by polymerase chain reaction (PCR) technique.

Results: The results indicated that, 110 samples of dairy products infected by Staphylococcus aureus were detected. Two cases (1.8%) of these infected samples were carrying both enterotoxin A and enterotoxin B genes. The frequencies of enterotoxin A genes were twenty-six cases (23/6%) and The frequencies of enterotoxin B genes were two cases (1/8%), respectively.

Conclusion: The detection of enterotoxin A and enterotoxin B genes, shows the most important role they have in bringing about superinfection. The detection of enterotoxin A and B genes, shows the most important role they have in bringing about superinfection. Enterotoxins SEA and SEB are heat stable; therefore heating has no effect on dairy products contaminated by enterotoxins and gastritis may occur in a short period of time. As PCR is a rapid, sensitive, specific and inexpensive method, we suggest that it can be replaced to traditionally assays for detecting Staphylococcus aureus enterotoxin.