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We characterized the prevalence, antibiotic susceptibility profiles, and genotypes of Staphylococcus aureus among US meat and poultry samples (n = 136). S. aureus contaminated 47% of samples, and multidrug resistance was common among isolates (52%). S. aureus genotypes and resistance profiles differed significantly among sample types, suggesting food animal-specific contamination.

Before the anthrax letter attacks of 2001, the developing field of microbial forensics relied on microbial genotyping schemes based on a small portion of a genome sequence. Amerithrax, the investigation into the anthrax letter attacks, applied high-resolution whole-genome sequencing and comparative genomics to identify key genetic features of the letters' Bacillus anthracis Ames strain. During systematic microbiological analysis of the spore material from the letters, we identified a number of morphological variants based on phenotypic characteristics and the ability to sporulate. The genomes of these morphological variants were sequenced and compared with that of the B. anthracis Ames ancestor, the progenitor of all B. anthracis Ames strains. Through comparative genomics, we identified four distinct loci with verifiable genetic mutations. Three of the four mutations could be directly linked to sporulation pathways in B. anthracis and more specifically to the regulation of the phosphorylation state of Spo0F, a key regulatory protein in the initiation of the sporulation cascade, thus linking phenotype to genotype. None of these variant genotypes were identified in single-colony environmental B. anthracis Ames isolates associated with the investigation. These genotypes were identified only in B. anthracis morphotypes isolated from the letters, indicating that the variants were not prevalent in the environment, not even the environments associated with the investigation. This study demonstrates the forensic value of systematic microbiological analysis combined with whole-genome sequencing and comparative genomics.

A forensic capability to help identify perpetrators and exclude innocent people should be an integral part of a strategy against terrorist attacks. Exercises have been conducted to increase our preparedness and response capabilities to chemical, biological, radiological, and nuclear (CBRN) terrorist attacks. However, incorporating forensic components into these exercises has been deficient. CBRN investigations rely on forensic results, so the need to integrate a forensic component and forensics experts into comprehensive exercises is paramount. This article provides guidance for planning and executing exercises at local, state, federal, and international levels that test the effectiveness of forensic capabilities for CBRN threats. The guidelines presented here apply both to situations where forensics is only a component of a more general exercise and where forensics is the primary focus of the exercise.

Monitoring antiviral resistance in influenza is critical to public health epidemiology and pandemic preparedness activities. Effective monitoring requires methods to detect low-level resistance and to monitor the change in resistance as a function of time and drug treatment. Resistance-conferring single-nucleotide mutations in influenza virus are ideal targets for such methods. In the present study, fives sets of paired TaqMan allele-specific PCR (ASPCR) assays were developed and validated for quantitative single-nucleotide polymorphism (SNP) analysis. This novel method using Delta Ct is termed allele-specific mixture analysis (ASMA) or FluASMA. The FluASMA assays target L26F, V27A, A30T, and S31N mutations in the A/Albany/1/98 (H3N2) M2 gene and H275Y mutation in the A/New Caledonia/20/99 (H1N1) NA gene and have a limit of quantification of 0.25-0.50% mutant. The error for % mutant estimation was less than 10% in all FluASMA assays, with intra-run Delta Ct coefficient of variance (CoV) at