Comparison of the phenotyping methods ID 32E and VITEK 2 compact GN with 16S rRNA gene sequencing for the identification of Enterobacter sakazakii.

A total of 34 isolates (28 Enterobacter sakazakii and 6 Enterobacteriaceae) from infant formulae, milk powder, and the production environment of milk powder factories were identified using ID 32E and VITEK 2 compact GN systems (bioMérieux, France). The ID 32E version 3.0 and VITEK 2 compact GN version 01.

The incompatibility between the PlcR- and AtxA-controlled regulons may have selected a nonsense mutation in Bacillus anthracis.

Bacillus anthracis, Bacillus thuringiensis and Bacillus cereus are members of the Bacillus cereus group. These bacteria express virulence in diverse ways in mammals and insects. The pathogenic properties of B.

Expression of a new operon from Bacillus subtilis, ykzB-ykoL, under the control of the TnrA and PhoP-phoR global regulators.

The ykzB and ykoL genes encode two peptides, of 51 and 60 amino acids, the functions of which are unknown. The ykzB and tnrA genes are contiguous and transcribed divergently. Expression of ykzB and ykoL is induced by glutamate and is under the control of the TnrA global regulator of nitrogen utilization.

Atomic force microscopy imaging of dried or living bacteria.

Atomic force microscopy (AFM) was used to obtain micrographs of dried bacteria in air, and of living ones in their culture medium. Images of dried bacteria were very similar to images obtained elsewhere by the much more complicated cryoetching preparation technique for transmission electron microscopy. Living bacteria were immobilized on a poly-L-lysine film, and directly observed in their culture medium at a resolution unattainable by any other technique applicable to living material.

The rpoN (sigma54) gene from Listeria monocytogenes is involved in resistance to mesentericin Y105, an antibacterial peptide from Leuconostoc mesenteroides.

To gain insight into the mode of action of mesentericin Y105, a bacteriocin bactericidal agent against Listeria monocytogenes, we undertook to identify the listerial factors mediating this susceptibility by using a genetic approach. Transposon mutants resistant to the bacteriocin were obtained. One of them corresponded to a transposon insertion in a gene (rpoN) encoding a putative protein (447 amino acids) with strong homologies to alternative transcriptional sigma54 factors, including that of Bacillus subtilis (38% identity).