جستجوی مقالات مرتبط با کلیدواژه "enterotoxin a" در نشریات گروه "پزشکی"

Staphylococcus aureus is responsible for the majority of food poisoning all around the world. Nasal carriers of S. aureus and foodstuffs need for handling are important sources and vehicles to transmit this pathogen to ready-to-eat foods. According to hygienic standards, confectioners should not be contaminated with S. aureus. This study aimed to detect nasal carriers and creamy pastries contaminated with enterotoxigenic S. aureus in confectioneries of Shiraz, Iran.

From the confectioneries of Shiraz city, 27 places in the north, south, center, west, and east areas were selected randomly then 100 creamy pastries samples and 117 nasal swabs were collected. Bacteriological and biochem- ical tests were performed to isolate S. aureus. The polymerase chain reaction (PCR) test was used to identify the virulence and enterotoxins genes of the S. aureus isolates. Agar disk diffusion was performed to find out the antibiotic resistance of the isolates.

Results revealed that 16.24 and 33 percent of workers and creamy pastries were contaminated with S. aureus respec- tively. Also, 100%, 37%, 58%, and 6% of nasal samples harbored femA, mecA, sea, and sec genes respectively. According to the results 97%, 70%, 54.5%, and 6% of creamy pastries isolates harbored femA, mecA, sea, and sec genes respectively. No isolate carried seb and sed genes. The results also showed that 41.5% of nasals and 5.5% of creamy pastry isolates har- bored both sea and sec genes. The sea was the most common enterotoxin gene observed in nasal and creamy pastries. The results of the antimicrobial resistance test showed that 68.42% of nasal and 48.48% of creamy pastry isolates were resistant to cefocxitn (FOX) respectively. Both nasal (89%) and creamy pastry (82%) isolates presented the highest resistance to pen- icillin (P) and the most sensitivity to trimethoprim-sulphamethoxazole (SXT) (94%). Most of the isolates were sensitive to erythromycin (E), aztreonam (AZM), tetracycline (TE), trimethoprim (TMP), and ciprofloxacin (CP). Isolates of S. aureus harboring multi-enterotoxin genes were resistant to more antibiotics than others.

The presence of enterotoxigenic S. aureus in the workers’ nasal samples and creamy pastries of Shiraz confec- tioneries was high which is a potential public health hazard.

Staphylococcus aureus is one of the most important human pathogens that produces a wide range of toxins and causes various diseases. Staphylococcal enterotoxin is the most common cause of food poisoning. In addition, S. aureus enterotoxins are classified into 18 serotypes A to U based on serological and biological properties.

The samples were isolated from clinical specimens and identified by routine bacteriological methods. The isolated S. aureus was evaluated by polymerase chain reaction (PCR) for the detection of the genes encoding SEA and SEA.

Based on the PCR results, 3 isolates possessed the enterotoxins B (SEB) gene while none of them showed enterotoxins A (SEA) gene.

The obtained results revealed that the clinical samples might be a potential source of the enterotoxigenic strains of S. aureus.

Staphylococcus aureus (S. aureus) is a pathogen in community-acquired or hospital infections. Hence, the identification of this pathogen in clinical samples is a health concern and demands continued surveillance and close monitoring. In the current study, S. aureus strains were isolated from various clinical specimens in the Shariati Hospital, Tehran, Iran. Samples were studied to discover S. aureus enterotoxin-coding genes A (sea), B (seb), C (sec), and D (sed). It was found that 21% enterotoxigenic S. aureus harbored sea gene, 39% were carried seb gene, 37% were positive for sec-gene, and 3% were carried sed gene. None of all S. aureus strains harbored more than one of the enterotoxigenic genes. Based on the data obtained from the current study, it could be suggested that seb and sec genes are good candidates for the identification of S. aureus in clinical specimens. Further investigations are required to discover the association between these genes and the pathogenicity of this bacteria, and finally using these data in clinical settings.

Staphylococcus aureus (S. aureus) is considered as one of the most dangerous pathogenic bacteria due to the production of extracellular toxins. The objective of this study was to determine the prevalence of S. aureus and to characterize the recovered strains for their enterotoxin-producing genes in raw cow milk.
During 9 months duration of the study, a total of 322 raw milk samples were collected from different markets in Isfahan province in Iran. S. aureus isolates were identified by bacteriology and biochemical tests. The isolates were typed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for detection of coa gene and genes encoding classic enterotoxins (sea, seb, sec and sed).
A total of 109 strains were positive for at least one type of staphylococcal enterotoxin genes with sea being the predominant. The isolates were grouped into 3 genotypes I, VIII and IX using RFLP analysis results of the genes.
The alarmingly high prevalence of S. aureus and their enterotoxin genes in raw cow milk should raise awareness about the food safety of such milk and milk products.

Bacillus cereus is a Gram-positive spore-forming bacterium, which causes food poisoning. Spores enable the persistence of B. cereus in the environment, and B. cereus strains can tolerate adverse environmental conditions, such as temperature and insufficient nutrients. B. cereus causes food poisoning via the production of two enterotoxins. Most isolates produce toxins leading to diarrhea (enterotoxins) and vomiting (emetic forms). Diarrhea is caused by the production of three different heat-labile enterotoxins: HBL, NHE, and cytotoxin K. A heat-stable toxin, cereulide, is responsible for emesis.
This study aimed to detect enterotoxigenic B. cereus isolates in cheese samples using the polymerase chain reaction (PCR).
Two-hundred pasteurized (n = 100) and nonpasteurized (n = 100) cheese samples were collected. The initial isolation was performed on PEMBA specific medium. Antibiotic susceptibility testing was performed using several antibiotic disks, according to the guidelines of the Clinical Laboratory and Standards Institute. Specific primers amplifying the hblA enterotoxin-encoding gene and bal hemolysin-encoding gene were used for the molecular detection of the toxins.
Ten samples were positive for the presence of B. cereus, with both Gram staining and biochemical reactions. All the isolates were resistant to penicillin and ampicillin but susceptible to vancomycin, erythromycin, and ciprofloxacin. Six and three isolates were resistant to tetracycline and trimethoprim-sulfamethoxazole, respectively. The hblA and bal genes were amplified in all the B. cereus isolates.
The prevalence of B. cereus among the cheese samples was low. All the isolates were positive for genes encoding the hblA enterotoxin and bal toxin.

Several virulence factors have been described in pathogenesis of Staphylococcus aureus strains. Staphylococcal Enterotoxins(SEs) that is one of the most factors, are belonging to important members of bacterial superantigens. Superantigens are defined by their ability to stimulate cytokine release from both T cells and macrophages. 13 different SEs are known that their function is not only as gastrointestinal toxins but also as superantigens.
Aim: The aim of this study was to evaluate the prevalence of SEs genes in isolates from patients in Ahwaz hospitals.
Material: This study was performed on 1280 clinical samples from patients who were referred to the four hospitals in Ahwaz. Samples were collected from urine, blood, skin chips and sputum of patients. Staphylococcus aureus isolates were identified by routine bacteriological methods. Genomic DNA was extracted by Phenol-chloroform method. The sets of enterotoxin genes(sea-sei) were amplified by multiplex PCR. PCR products were analyzed by electrophoresis.
In this study 231 Staphylococcus aureus were isolated from urine , blood, skin chips and spatum samples. 89(39%) strains had enterotoxin gene. The frequency of sea (17%), seg (15%), sec (6%), sed and seh (5.6%), seb (5.1%) and sei (9.5%) were reported. There was no see gene among isolates. The study of genes simultaneously showed that the frequency of two genes and three genes were 20% and 17 %.
Given the importance of nosocomial Staphylococcus aureus infections and the role of SEs as superantigen in the development of various diseases, study of these genes in clinical specimen is necessary.

Rheumatoid arthritis (RA) is the most common chronic inflammatory disease. The staphylococcal superantigens are considered as the causative agent of RA disease.. This study aimed to assess the presence of staphylococcal enterotoxin D in synovial fluid and blood of patients with RA..Patients and A total of 120 blood and SF samples of patients with RA were studied. Bacterial culture, primer pairs design, polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) methods have been used to assess of the staphylococcal enterotoxin D. The data were analyzed through descriptive statistics.. During this study and after sequential subcultures, only 5 bacterial strains were isolated. The results of PCR showed the presence of staphylococcal enterotoxin D gene in almost 50% of SF and also in 48.4% of blood samples of patients with RA. Similarly, the ELISA method detected staphylococcal enterotoxin D in 36.16% of SF and in 33.33% of blood of patients with RA.. The result of this study showed that a high percentage of patients with RA have shown staphylococcal enterotoxin D (superantigen D) or entD gene in SF and in blood. However, the origin of this superantigen was not clarified and no Staphylococcus aureus enterotoxin D producer was isolated. This finding indicates other role of this superantigen besides its intoxication. Therefore, staphylococcal enterotoxin D as a biomarker may provide a good model for the diagnosis and treatment of patients with RA..

Staphylococcus aureus, the major virulence factor of hospital and community acquired infections, secretes numerous exotoxins (super antigens), which may affect immunological and inflammatory status in psoriatic skin lesion. This study is designed to compare the S. aureus super antigens level in sera of psoriatic patients with normal cases (nevus).Patients and A case control study was performed in dermatology ward of Rasoul Hospital in Tehran, IR Iran (2008 - 2010). Staphylococcal super antigens (Entrotoxin A, B, D and TSST1) were measured in serum of 41 psoriatic patients and 28 normal persons (Nevus) by ELISA. Chi square values (CI 95%, P value < 0.05) were calculated for all categorical variables. In this study 63.4% (26) of cases were male, 36.6% (15) were female. Age ranged from 4 months to 64 years old, with a mean age of 33.7 ± 15.4 years. Type of skin disease in cases: 20% (8) were inflicted by the Gutate form of the disease; 59% (23) with chronic plaque psoriasis (CPP), 7.7% (3) with erythrodermic and 12.8% (5) had other types of the disease (plaque, pustular, inverse). TSST (toxic shock syndrome toxin) was detected in 47% (20/41) of cases and in 6% (1/28) of the controls with a significant difference. (P value = 0.000) Entrotoxins (A, B, D) were detected in the sera of 48.8% (21/41) of cases; and only 6 %(1/21) of controls, showed significant differences (P value = 0.000) positive TSST was more common in spring, and correlates with CPP type of psoriasis, but not related to patient`s gender and age. In this study, S. aureus were 25 times more in psoriatic patients. Super antigens should be first detected in the serum samples; if negative, the skin lesions should be examined by PCR especially in chronic types of disease. Adding the antibiotics against S. aureus to other conventional treatments might be helpful. It has a more important and significant role in children with acute infection.

Staphylococcus aureus is a major human pathogen producing different types of toxins. Enterotoxin A (SEA) is the most common type among clinical and food-related strains. The aim of the present study was to examine the prevalence of sea in clinical isolates of S. aureus. Moreover, the correlation between sea producing strains and type of infection as well as resistance to antibiotics is also considered. 128 S. aureus isolates randomly collected from different clinical samples in Tehran University Hospitals from February 2008 to June 2008. Patients’ information including sex, infection type and the hospital where samples come from were recorded. The sea gene was observed among 60 (46.9%) of clinical isolates. There was a significant correlation between prevalence of sea gene and type of infection (P = 0.01). Furthermore, significant correlation was detected between the presence of sea gene and resistance to the most of antibiotics used in this study. The significant relationship between the type of infection and S. aureus isolates carrying sea indicates the interaction quality of the S. aureus pathogen and the host as well as the pathogenic role of S. aureus.