The spores of six strains of Bacillus anthracis (four virulent and two avirulent) were compared with those of four other types of spore-forming bacteria for their resistance to four liquid chemical sporicides (sodium hypochlorite at 5,000 ppm available chlorine, 70,000 ppm accelerated H 2 O 2 , 1,000 ppm chlorine dioxide, and 3,000 ppm peracetic acid). All test bacteria were grown in a 1:10 dilution of Columbia broth (with manganese) incubated at 37°C for 72 h. The spore suspensions, heat treated at 80°C for 10 min to rid them of any viable vegetative cells, contained 1 ؋ 10 8 to 3 ؋ 10 8 CFU/ml. The second tier of the quantitative carrier test (QCT-2), a standard of ASTM International, was used to assess for sporicidal activity, with disks (1 cm in diameter) of brushed and magnetized stainless steel as spore carriers. Each carrier, with 10 l (>10 6 CFU) of the test spore suspension in a soil load, was dried and then overlaid with 50 l of the sporicide being evaluated. The contact time at room temperature ranged from 5 to 20 min, and the arbitrarily set criterion for acceptable sporicidal activity was a reduction of >10 6 in viable spore count. Each test was repeated at least three times. In the final analysis, the spores of Bacillus licheniformis (ATCC 14580 T ) and Bacillus subtilis (ATCC 6051 T ) proved to be generally more resistant than the spores of the strains of B. anthracis tested. The use of one or both of the safe and easy-to-handle surrogates identified here should help in developing safer and more-effective sporicides and also in evaluating the field effectiveness of existing and newer formulations in the decontamination of objects and surfaces suspected of B. anthracis contamination.Bacillus anthracis, the etiologic agent of anthrax, is a sporeforming zoonotic pathogen (3). Its spores are hardy enough for weaponization and environmental dispersal (10); viable spores of the organism have been recovered after many decades from deliberately contaminated sites (6). The more-recent and malicious use of the spores of B. anthracis in the United States (14) clearly attests to the potential of this organism to cause mortality, morbidity, and general societal disruption and reemphasizes the importance of having available suitable remedial measures for countering any subsequent accidental or deliberate release of such spores.The biohazardous nature of B. anthracis mandates its handling in laboratories at biosafety level 3, also called containment level 3 (CL-3), in Canada. The availability of only a very limited number of such facilities seriously hampers experimentation with this increasingly significant pathogen, a recognized biothreat agent. This is especially true for developmental studies on decontamination agents, as such work is often conducted in settings without biosafety level 3 facilities. This study evaluated several potential bacterial surrogates for the spores of B. anthracis to enable a wider search for safer and more-effective liquid chemical sporicides to deal with the threat of anthrax. MATE...

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Mass spectrometry-based phenotypic H-antigen typing (MS-H) combined with whole-genome-sequencing-based genetic identification of H antigens, O antigens, and toxins (WGS-HOT) was used to type 60 clinical Escherichia coli isolates, 43 of which were previously identified as nonmotile, H type undetermined, or O rough by serotyping or having shown discordant MS-H and serotyping results. Whole-genome sequencing confirmed that MS-H was able to provide more accurate data regarding H antigen expression than serotyping. Further, enhanced and more confident O antigen identification resulted from gene cluster based typing in combination with conventional typing based on the gene pair comprising wzx and wzy and that comprising wzm and wzt. The O antigen was identified in 94.6% of the isolates when the two genetic O typing approaches (gene pair and gene cluster) were used in conjunction, in comparison to 78.6% when the gene pair database was used alone. In addition, 98.2% of the isolates showed the existence of genes for various toxins and/or virulence factors, among which verotoxins (Shiga toxin 1 and/or Shiga toxin 2) were 100% concordant with conventional PCR based testing results. With more applications of mass spectrometry and whole-genome sequencing in clinical microbiology laboratories, this combined phenotypic and genetic typing platform (MS-H plus WGS-HOT) should be ideal for pathogenic E. coli typing.