Peptoniphilus methioninivorax sp. nov., a Gram-positive anaerobic coccus isolated from retail ground beef.

Strain NRRL B-23883(T) was isolated from retail ground beef as part of a study on the genetic diversity of Clostridium perfringens. The strain was found to be a strictly anaerobic, Gram-positive coccus that was able to utilize peptone as a sole carbon source. Analysis of the 16S rRNA gene sequence revealed that the strain was closely related to species within the genera Peptoniphilus and Anaerosphaera, but it was substantially different from the closest recognized species by nearly 10 % sequence divergence. The strain was also found to be closely related (>99 % sequence similarity) to an uncultured bacterial strain that was sequenced from a 16S rRNA gene clone library constructed to characterize the bacterial community of faeces from a captive spotted hyena. Strain NRRL B-23883(T) shared the peptidoglycan type A4ß, l-Orn-d-Glu with members of the genus Peptoniphilus. Further phenotypic analysis revealed that strain NRRL B-23883(T) was able to utilize glycyl l-methionine as a sole carbon source, in contrast to other species of the genus Peptoniphilus. Therefore, it is proposed that the isolate represents a novel species, Peptoniphilus methioninivorax sp. nov.; the type strain is NRRL B-23883(T) ( = DSM 22461(T)).

Analysis of core housekeeping and virulence genes reveals cryptic lineages of Clostridium perfringens that are associated with distinct disease presentations.

Clostridium perfringens is an important human and animal pathogen that causes a number of diseases that vary in their etiology and severity. Differences between strains regarding toxin gene composition and toxin production partly explain why some strains cause radically different diseases than others. However, they do not provide a complete explanation. The purpose of this study was to determine if there is a phylogenetic component that explains the variance in C. perfringens strain virulence by assessing patterns of genetic polymorphism in genes (colA gyrA, plc, pfoS, and rplL) that form part of the core genome in 248 type A strains. We found that purifying selection plays a central role in shaping the patterns of nucleotide substitution and polymorphism in both housekeeping and virulence genes. In contrast, recombination was found to be a significant factor only for the virulence genes plc and colA and the housekeeping gene gyrA. Finally, we found that the strains grouped into five distinct evolutionary lineages that show evidence of host adaptation and the early stages of speciation. The discovery of these previously unknown lineages and their association with distinct disease presentations carries important implications for human and veterinary clostridial disease epidemiology and provides important insights into the pathways through which virulence has evolved in C. perfringens.

Mass spectrometric analysis of lipopeptides from Bacillus strains isolated from diverse geographical locations.

Matrix-assisted laser desorption/ionization time-of-flight MS (MALDI-TOF MS) has been applied to characterize lipopeptide biomarkers from 54 different strains of Bacillis from most taxa within the Bacillis subtilis-Bacillis licheniformis clade, isolated from seven geographic locations on five continents. Even the most narrowly defined taxa are diverse in terms of the lipopeptide profiles. Many strains produce previously identified compounds with known antimicrobial properties (e.g. polymyxins and bacitracins), whereas other compounds represent novel classes that were hitherto unknown. Of particular interest is the novel 942/958 Da biomarkers produced by B. s. spizizeni desert strains and several type strains.

Phylogeny and molecular taxonomy of the Bacillus subtilis species complex and description of Bacillus subtilis subsp. inaquosorum subsp. nov.

The Bacillus subtilis species complex is a tight assemblage of closely related species. For many years, it has been recognized that these species cannot be differentiated on the basis of phenotypic characteristics. Recently, it has been shown that phylogenetic analysis of the 16S rRNA gene also fails to differentiate species within the complex due to the highly conserved nature of the gene, yet DNA-DNA hybridization values fall well below 70 % for the same species comparisons. As a complementary approach, we propose that phylogenetic analysis of multiple protein-coding loci can be used as a means to detect and differentiate novel Bacillus taxa. Indeed, our phylogenetic analyses revealed the existence of a previously unknown group of strains closely related to, but distinct from, Bacillus subtilis subsp. spizizenii. Results of matrix-assisted laser desorption ionization-time of flight mass spectrometry analyses revealed that the group produces a novel surfactin-like lipopeptide with mass m/z 1120.8 that is not produced by the other currently recognized subspecies. In addition, the group displayed differences in the total cellular content of the fatty acids C(16 : 0) and iso-C(17 : 1)omega10c that distinguish it from the closely related B. subtilis subsp. spizizenii. Consequently, the correlation of these novel phenotypic traits with the phylogenetic distinctiveness of this previously unknown subspecies group showed that phylogenetic analysis of multiple protein-coding loci can be used as a means to detect and differentiate novel Bacillus taxa. Therefore, we propose that this new group should be recognized as representing a novel taxon, Bacillus subtilis subsp. inaquosorum subsp. nov., with the type strain NRRL B-23052(T) (=KCTC 13429(T)=BGSC 3A28(T)).

Bacterial species diversity in cigarettes linked to an investigation of severe pneumonitis in U.S. Military personnel deployed in operation iraqi freedom.

This report presents results from a study on the bacterial diversity of cigarette brands collected from military personnel during the U.S. Army's investigation of a series of cases of acute eosinophilic pneumonitis in military personnel deployed in Operation Iraqi Freedom. Eight species of Bacillus, including five new species, and one new species of Kurthia were isolated from the cigarettes. Some of these species have been identified elsewhere as causes of hypersensitivity pneumonitis and other respiratory syndromes. All of the isolates were facultative anaerobes, and many displayed mucoid growth under anaerobic conditions. In addition, many isolates also displayed the ability to form surface biofilms under liquid culture. Although biofilm formation and mucoid growth were not correlated, the former was found to be much more pronounced under anaerobic conditions as opposed to aerobic ones. The implications of these findings are discussed.