Development and validation of a real-time quantitative PCR assay for rapid identification of Bacillus anthracis in environmental samples

A real-time polymerase chain reaction (PCR) assay was developed for rapid identification of Bacillus anthracis in environmental samples. These samples often harbor Bacillus cereus bacteria closely related to B. anthracis, which may hinder its specific identification by resulting in false positive signals. The assay consists of two duplex real-time PCR: the first PCR allows amplification of a sequence specific of the B. cereus group (B. anthracis, B. cereus, Bacillus thuringiensis, Bacillus weihenstephanensis, Bacillus pseudomycoides, and Bacillus mycoides) within the phosphoenolpyruvate/sugar phosphotransferase system I gene and a B. anthracis specific single nucleotide polymorphism within the adenylosuccinate synthetase gene. The second real-time PCR assay targets the lethal factor gene from virulence plasmid pXO1 and the capsule synthesis gene from virulence plasmid pXO2. Specificity of the assay is enhanced by the use of minor groove binding probes and/or locked nucleic acids probes. The assay was validated on 304 bacterial strains including 37 B. anthracis, 67 B. cereus group, 54 strains of non-cereus group Bacillus, and 146 Gram-positive and Gram-negative bacteria strains. The assay was performed on various environmental samples spiked with B. anthracis or B. cereus spores. The assay allowed an accurate identification of B. anthracis in environmental samples. This study provides a rapid and reliable method for improving rapid identification of B. anthracis in field operational conditions.

Prevalence and associated factors of viral hepatitis and transferrin elevations in 5036 patients admitted to the emergency room of a Swiss university hospital: cross-sectional study

BACKGROUND: The epidemiology of liver disease in patients admitted to emergency rooms is largely unknown. The current study aimed to measure the prevalence of viral hepatitis B and C infection and pathological laboratory values of liver disease in such a population, and to study factors associated with these measurements. METHODS: Cross-sectional study in patients admitted to the emergency room of a university hospital. No formal exclusion criteria. Determination of anti-HBs, anti-HCV, transferrin saturation, alanine aminotransferase, and obtaining answers from a study-specific questionnaire. RESULTS: The study included 5'036 patients, representing a 14.9% sample of the target population during the study period. Prevalence of anti-HBc and anti-HCV was 6.7% (95%CI 6.0% to 7.4%) and 2.7% (2.3% to 3.2%), respectively. Factors independently associated with positive anti-HBc were intravenous drug abuse (OR 18.3; 11.3 to 29.7), foreign country of birth (3.4; 2.6 to 4.4), non-white ethnicity (2.7; 1.9 to 3.8) and age > or =60 (2.0; 1.5 to 2.8). Positive anti-HCV was associated with intravenous drug abuse (78.9; 43.4 to 143.6), blood transfusion (1.7; 1.1 to 2.8) and abdominal pain (2.7; 1.5 to 4.8). 75% of all participants were not vaccinated against hepatitis B or did not know their vaccination status. Among anti-HCV positive patients only 49% knew about their infection and 51% reported regular alcohol consumption. Transferrin saturation was elevated in 3.3% and was associated with fatigue (prevalence ratio 1.9; 1.2 to 2.8). CONCLUSION: Emergency rooms should be considered as targets for public health programs that encourage vaccination, patient education and screening of high-risk patients for liver disease with subsequent referral for treatment if indicated.