The bioterrorism-associated human anthrax epidemic in the fall of 2001 highlighted the need for a sensitive, reproducible, and specific laboratory test for the confirmatory diagnosis of human anthrax. The Centers for Disease Control and Prevention developed, optimized, and rapidly qualified an enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibodies to Bacillus anthracis protective antigen (PA) in human serum. The qualified ELISA had a minimum detection limit of 0.06 µg/mL, a reliable lower limit of detection of 0.09 µg/mL, and a lower limit of quantification in undiluted serum specimens of 3.0 µg/mL anti-PA IgG. The diagnostic sensitivity of the assay was 97.8%, and the diagnostic specificity was 94.2%. A competitive inhibition anti-PA IgG ELISA was also developed to enhance diagnostic specificity to 100%. The anti-PA ELISAs proved valuable for the confirmation of cases of cutaneous and inhalational anthrax and evaluation of patients in whom the diagnosis of anthrax was being considered.

Four isolates (FSL S4-120 T , FSL S4-696, FSL S4-710, and FSL S4-965) of Gram-positive, motile, facultatively anaerobic, non-spore-forming bacilli that were phenotypically similar to species of the genus Listeria were isolated from soil, standing water and flowing water samples obtained from the natural environment in the Finger Lakes National Forest, New York, USA. The four isolates were closely related to one another and were determined to be the same species by whole genome DNA-DNA hybridization studies (.82 % relatedness at 55 6C and .76 % relatedness at 70 6C with 0.0-0.5 % divergence). 16S rRNA gene sequence analysis confirmed their close phylogenetic relatedness to Listeria monocytogenes and Listeria innocua and more distant relatedness to Listeria welshimeri, L. seeligeri, L. ivanovii and L. grayi. Phylogenetic analysis of partial sequences for sigB, gap, and prs showed that these isolates form a wellsupported sistergroup to L. monocytogenes. The four isolates were sufficiently different from L. monocytogenes and L. innocua by DNA-DNA hybridization to warrant their designation as a new species of the genus Listeria. The four isolates yielded positive reactions in the AccuProbe test that is purported to be specific for L. monocytogenes, did not ferment L-rhamnose, were nonhaemolytic on blood agar media, and did not contain a homologue of the L. monocytogenes virulence gene island. On the basis of their phenotypic characteristics and their genotypic distinctiveness from L. monocytogenes and L. innocua, the four isolates should be classified as a new species within the genus Listeria, for which the name Listeria marthii sp. nov. is proposed. The type strain of L. marthii is FSL S4-120 T (5ATCC BAA-1595 T 5BEIR NR 9579 T 5CCUG 56148 T ). L. marthii has not been associated with human or animal disease at this time.

Laboratory-based surveillance of salmonella isolates serotyped at four state health departments (Illinois, Michigan, Minnesota and Wisconsin) led to the identification of multistate outbreaks of salmonella infections during 1990 (176 cases of S. javiana) and 1993 (100 cases of S. montevideo). Community-based case-control studies and product traceback implicated consumption of tomatoes from a single South Carolina tomato packer (Packer A) MOR 16.0; 95% CI2.1, 120.6; P < 0.0001 in 1990 and again in 1993 (MOR 5.7; 95 % CI 1.5, 21.9; P = 0.01) as the likely vehicle. Contamination likely occurred at the packing shed, where field grown tomatoes were dumped into a common water bath. These outbreaks represent part of a growing trend of large geographically dispersed outbreaks caused by sporadic or low-level contamination of widely distributed food items. Controlling contamination of agricultural commodities that are also ready-to-eat foods, particularly fruits and vegetables, presents a major challenge to industry, regulators and public health officials.

Comparison of the entire coding sequence of flaA (1,764 nucleotides) from 15 isolates of Campylobacter jejuni showed two regions of high variability, one region approximately from base positions 700 to 1,450 and a short variable region (SVR) from base positions 450 to 600. Parsimony analysis of the SVR sequences yielded a dendrogram similar to that which was derived by analysis of the entire gene. PCR was used to generate templates, and the SVR was sequenced with primers constructed to hybridize to conserved flanking sequences. The SVRs of 22 isolates of C. jejuni from four outbreaks that have been well characterized and a larger panel of isolates from three additional outbreaks were sequenced. Analysis of the nucleotide sequences produced results that grouped the isolates very similarly to other subtyping techniques. Sequence data were also generated for isolates from three additional outbreaks. Categorizing the isolates by fla SVR DNA sequence placed them in epidemiologically relevant groups. Sequence analysis of the C. jejuni flaA SVR may be a useful tool for epidemiologic investigations and could complement or replace serotyping and other subtyping methods.