Enterotoxin Synthesis by the Staphylococci*

In many countries Staphylococcus aureus is considered to be the second or third most common pathogen causing outbreaks of food poisoning, only outnumbered by Salmonella spp. and in competition with Clostridium perfringens. Often Ž . the consumption of ham or meat containing staphylococcal enterotoxins SE is identified as cause of the illness. Thus, to gain an insight into the prevalence of S. aureus and its emetic enterotoxins in raw pork and uncooked smoked ham and to investigate how the prevalence of the pathogen is influenced during the fabrication process, a total of 135 samples of raw pork, salted meat and ready-for-sale uncooked smoked ham were examined for the prevalence of S. aureus and Ž . staphylococcal enterotoxins A to D SEA-SED . To this means classical cultural methods were employed as well as Ž . molecular biological techniques PCR and the results were compared.In 25.9% of all samples S. aureus was detected by culture whereas 51.1% of the samples showed a positive result when PCR was used for the detection of the pathogen. Fresh meat was contaminated most often. By PCR, 62.2% were identified as being S. aureus positive compared to 57.7% positive samples using the cultural technique. The detection rate during the fabrication process declined significantly. The pathogen was cultivated from 8.9% of the salted meat samples. Here, 55.6% of the samples reacted positively in the PCR, and finally, in approximately a third of the ready-for-sale smoked hams, S. aureus genes were found. From 11.1% of these samples, the pathogen could be isolated by culture. From these results, we conclude that the PCR used in this study is more sensitive than the classical cultural method.By PCR, one or more staphylococcal enterotoxin genes were found in 24 of the 135 examined samples. This means that 34.8% of the staphylococcal strains identified using the PCR technique were enterotoxigenic. Using the SET-RPLA, a percentage of 28.6% enterotoxigenic isolates was ascertained. No staphylococcal enterotoxin formation was detected by the SET-RPLA in ready-for-sale ham, although SE-genes were found by PCR. The detection of SE-genes by PCR is faster and easier to perform than the SET-RPLA. q 2001 Elsevier Science B.V. All rights reserved.

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“…ing Bergdoll et al, 1974 . In this study, staphylococcal enterotoxin A was found most often, but we Ž .…”

Section: Discussionmentioning

confidence: 99%

“…2000 , of which the staphylococcal enterotoxins A to D are isolated most often from outbreaks of food Ž . poisoning Bergdoll et al, 1974 .…”

Section: Introductionmentioning

confidence: 99%

Prevalence of Staphylococcus aureus and staphylococcal enterotoxins in raw pork and uncooked smoked ham—a comparison of classical culturing detection and RFLP-PCR

Atanassova

Meindl

Ring

2001

International Journal of Food Microbiology

144

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“…The staphylococcal enterotoxins are a group of secreted proteins that cause emesis when orally administered to primates (6). To date, a number of enterotoxins have been characterized based on their serological reactivities and designated SEA to SEJ, including subtypes SEC 1 to SEC 3 (5,8,24,29,(32)(33)(34).Though staphylococcal enterotoxins are similar in structure and biological properties (22), they differ with respect to genetic localization, amount of toxin produced, and mechanism of gene regulation. The genes for SEA and SEE are carried on prophage, some of which are defective prophage.…”

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confidence: 99%

Characterization of the Promoter Elements for the Staphylococcal Enterotoxin D Gene

Zhang

Stewart

2000

J Bacteriol

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Deletion analysis of the promoter for the Staphylococcus aureus enterotoxin D determinant indicated that a 52-bp sequence, from ؊34 to ؉18, was sufficient for sed promoter function and agr regulation. A consensus ؊10 Pribnow box sequence, a less conserved ؊35 sequence, and a TG dinucleotide motif were present. Transcribed sequences (؉1 to ؉18) are essential for promoter activity.Staphylococcal food poisoning is an intoxication resulting from ingestion of foods contaminated with enterotoxin producing Staphylococcus aureus strains (16). The symptoms include emesis, diarrhea, abdominal cramping, and in severe cases, fever and shock (6,30,31). The staphylococcal enterotoxins are a group of secreted proteins that cause emesis when orally administered to primates (6). To date, a number of enterotoxins have been characterized based on their serological reactivities and designated SEA to SEJ, including subtypes SEC 1 to SEC 3 (5,8,24,29,(32)(33)(34).Though staphylococcal enterotoxins are similar in structure and biological properties (22), they differ with respect to genetic localization, amount of toxin produced, and mechanism of gene regulation. The genes for SEA and SEE are carried on prophage, some of which are defective prophage. SED and SEJ gene determinants are carried on the same penicillinasetype plasmid. The genes for SEB and SEC are chromosomal, but the nature of the genetic elements on which they reside has not been elucidated (7,18,19). SEB and SEC are expressed in greater quantities than the other enterotoxins, often on the order of 100 g/ml of culture supernatant, whereas maximal production of SEA, SED, and SEE is usually less than 10 g/ml (3). Furthermore, SEA is produced throughout the log phase of growth, while SEB, SEC, and SED are produced in greater quantities during the transition from the exponential to the stationary phases of growth (5). The latter expression pattern is characteristic of many staphylococcal exoprotein virulence factors which are under the control of the accessory gene regulator (agr) two-component regulatory system (25). The transcription of seb, sec, and sed is subject to regulation by the agr system. In agr mutant strains, mRNA steady-state levels were reduced 4-fold for seb, 5.5-fold for sed, and 2 to 3-fold for sec (2, 28).Information regarding the promoter elements of the staphylococcal enterotoxin genes is very limited. The sea promoter has been identified by means of primer extension analysis in conjunction with deletion mutagenesis. However, detailed characterization of the promoters for the agr-regulated enterotoxin genes has not been reported. Promoter sequences for seb and sed were defined by mapping the transcription start site and by comparison to Escherichia coli promoter consensus Ϫ10 and Ϫ35 sequences. Mahmood and Khan found that a region upstream of the Ϫ35 element, at positions Ϫ93 to Ϫ58, is required for seb expression (21). Although primer extension studies have been carried out on sed, only a Pribnow box could be identified in the sequence (2). No convincing...

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“…Nasal tampons are primarily applied to control epistaxis and after intranasal surgical procedures, as well as for internal stabilization of bone cartilage after operations. In addition to homeostasis, nasal tampons are beneficial in the prevention of postoperative synechia and restenosis development (11)(12)(13). Therefore, another important problem in using tampon systems is that of which type of nasal tampon should be used and how long it should be kept intranasally (13,14).…”

Section: Discussionmentioning

confidence: 99%

“…In addition to homeostasis, nasal tampons are beneficial in the prevention of postoperative synechia and restenosis development (11)(12)(13). Therefore, another important problem in using tampon systems is that of which type of nasal tampon should be used and how long it should be kept intranasally (13,14). Tampon application after nasal surgery depends upon the surgeon, such that some investigators may keep the tampon inserted for 1 day postoperatively while others may leave it inserted until the seventh postoperative day (14,15).…”

Section: Discussionmentioning

confidence: 99%

Ocular surface culture changes in patients after septoplasty

Özkırış¹,

Gencer²,

Kader³

et al. 2014

Turk J Med Sci

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IntroductionNasal airway obstruction is one of the most common complaints encountered by ear-nose-throat (ENT) specialists. In patients with chronic nasal obstruction due to mechanical causes, surgical procedures such as septoplasty or submucosal septum resection are applied in order to increase nasal air flow (1). Since the nasal cavity and the eyes are interconnected via the nasolacrimal duct and they neighbor each other, an infection developing in one may affect the other.Nasal and oropharyngeal flora consist of numerous strains of aerobic bacteria that maintain a balance through strategies of antagonism and coexistence. The location, severity, and complexity of nasal septal deviation influence airflow dynamics in the nasal cavity (2). This interaction may also be observed after septoplasty operations. This condition may affect the nasal cavity and flora (3).The increase in the local microbiological load, due to both tampon placement and trauma, further supports the potential microbiological interrelation between the nose and eyes. A literature search revealed that no studies investigating such an interrelationship have been conducted up to now. Therefore, the aim of this study was to investigate, both pre-and postoperatively, whether there are potential changes via the above-mentioned pathways (i.e. the nasolacrimal duct or directly via the lamina papyracea) in the microbiologic flora of the eyes of patients who underwent classical septoplasty due to septal deviation. Materials and methodsForty patients, who were diagnosed with septal deviation and underwent a septoplasty operation in our ENT Department at Bozok University Training and Research Hospital between January 2012 and April 2012, were enrolled in this study. This study was carried out in accordance with the Helsinki Declaration of the World Medical Association and was approved by the institutional ethics committee of Bozok University. Informed consent was obtained from all the patients.Patients with vasomotor rhinitis, nasal polyposis, allergic rhinitis, autoimmune disorders, and systemic Aim: To investigate the interrelationships between pre-and postoperative microbiological changes by taking samples from both eyes of 40 patients who underwent septoplasty due to septal deviation. Materials and methods:Forty patients diagnosed with septal deviation who underwent a septoplasty operation under general anesthesia were enrolled in this study. The study was conducted on 40 patients who met the inclusion criteria and attended follow-up visits. One day before the operation and 48 h after the operation, cultures were taken individually from the conjunctivas and puncta of both eyes and sent to the microbiology laboratory.Results: Patients who were candidates for nasal surgery due to their symptoms and clinical examination results were randomly selected and 40 of these completed the study. No statistically significant differences in bacterial growth were observed between the eyes before the operation (P > 0.05). There were, however, statistically significant ...

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Enterotoxin Synthesis by the Staphylococci*

Cited by 31 publications

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Prevalence of Staphylococcus aureus and staphylococcal enterotoxins in raw pork and uncooked smoked ham—a comparison of classical culturing detection and RFLP-PCR

Prevalence of Staphylococcus aureus and staphylococcal enterotoxins in raw pork and uncooked smoked ham—a comparison of classical culturing detection and RFLP-PCR

Characterization of the Promoter Elements for the Staphylococcal Enterotoxin D Gene

Ocular surface culture changes in patients after septoplasty

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