Diagnostic real-time PCR assays for the detection of emetic Bacillus cereus strains in foods and recent food-borne outbreaks.

نویسندگان

  • Martina Fricker
  • Ute Messelhäusser
  • Ulrich Busch
  • Siegfried Scherer
  • Monika Ehling-Schulz
چکیده

Cereulide-producing Bacillus cereus can cause an emetic type of food-borne disease that mimics the symptoms provoked by Staphylococcus aureus. Based on the recently discovered genetic background for cereulide formation, a novel 5' nuclease (TaqMan) real-time PCR assay was developed to provide a rapid and sensitive method for the specific detection of emetic B. cereus in food. The TaqMan assay includes an internal amplification control and primers and a probe designed to target a highly specific part of the cereulide synthetase genes. Additionally, a specific SYBR green I assay was developed and extended to create a duplex SYBR green I assay for the one-step identification and discrimination of the two emesis-causing food pathogens B. cereus and S. aureus. The inclusivity and exclusivity of the assay were assessed using a panel of 100 strains, including 23 emetic B. cereus and 14 S. aureus strains. Different methods for DNA isolation from artificially contaminated foods were evaluated, and established real-time assays were used to analyze two recent emetic food poisonings in southern Germany. One of the food-borne outbreaks included 17 children visiting a day care center who vomited after consuming a reheated rice dish, collapsed, and were hospitalized; the other case concerned a single food-poisoning incident occurring after consumption of cauliflower. Within 2 h, the etiological agent of these food poisonings was identified as emetic B. cereus by using the real-time PCR assay.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Detection of emetic Bacillus cereus by real-time PCR in foods.

The simplex real-time PCR assays based on the TaqMan probe and SYBR green I, which target cereulide synthetase genes (ces genes) were used for rapidly, reliably and sensitively identifying the emetic strains from among Bacillus cereus strains isolated from different sources. Only the emetic strains showed positive reactions to the real-time PCR assays, but all examined strains of diarrheal B. c...

متن کامل

Isolation and identification of Bacillus cereus of dry bulk and packaged vegetables by culture and PCR

Background: Bacillus cereus is an endemic, Gram-positive, rod-shaped, motile, beta hemolytic bacterium. Some strains are harmful to humans and cause foodborne illness and it's spore is resistant against difficult condition In recent years life style and feeding habits have changed and an increase in the use of ready to eat product has raised concern about quality and health assessment. Dehydrat...

متن کامل

Identification of emetic toxin producing Bacillus cereus strains by a novel molecular assay.

Bacillus cereus causes two types of gastrointestinal diseases: emesis and diarrhea. The emetic type of the disease is attributed to the heat-stable depsipeptide cereulide and symptoms resemble Staphylococcus aureus intoxication, but there is no rapid method available to detect B. cereus strains causing this type of disease. In this study, a polymerase chain reaction (PCR) fragment of unknown fu...

متن کامل

Rapid molecular techniques for detection of foodborne Bacillus cereus pathogen

Background and Objective: Bacillus cereus is responsible for several outbreaks of foodborne diseases. Therefore, the purpose of the study was to replace routine culture testing, by employing PCR directly from food to detect the bacteria and its enterotoxins. Methods: In the present study, a total of 75 Kibda sandwiches, Sausage sandwiches, Luncheon chicken, Luncheon meat and shawarma sandwiche...

متن کامل

Emetic toxin-producing strains of Bacillus cereus show distinct characteristics within the Bacillus cereus group.

One hundred representative strains of Bacillus cereus were selected from a total collection of 372 B. cereus strains using two typing methods (RAPD and FT-IR) to investigate if emetic toxin-producing hazardous B. cereus strains possess characteristic growth and heat resistance profiles. The strains were classified into three groups: emetic toxin (cereulide)-producing strains (n=17), strains con...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Applied and environmental microbiology

دوره 73 6  شماره 

صفحات  -

تاریخ انتشار 2007