Very different toxins are responsible for the two types of gastrointestinal diseases caused by Bacillus cereus: the diarrhoeal syndrome is linked to nonhemolytic enterotoxin NHE, hemolytic enterotoxin HBL, and cytotoxin K, whereas emesis is caused by the action of the depsipeptide toxin cereulide. The recently identified cereulide synthetase genes permitted development of a molecular assay that targets all toxins known to be involved in food poisoning in a single reaction, using only four different sets of primers. The enterotoxin genes of 49 strains, belonging to different phylogenetic branches of the B. cereus group, were partially sequenced to encompass the molecular diversity of these genes. The sequence alignments illustrated the high molecular polymorphism of B. cereus enterotoxin genes, which is necessary to consider when establishing PCR systems. Primers directed towards the enterotoxin complex genes were located in different CDSs of the corresponding operons to target two toxin genes with one single set of primers. The specificity of the assay was assessed using a panel of B. cereus strains with known toxin profiles and was successfully applied to characterize strains from food and clinical diagnostic labs as well as for the toxin gene profiling of B. cereus isolated from silo tank populations.

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The essential protein lysyl-tRNA synthetase (LysRS) exists in two unrelated forms, a class I and a class II-type aminoacyl-tRNA synthetase. Comparative genome sequence analysis revealed that Borrelia burgdorferi sensu lato, the etiological agent of Lyme disease, contains a class I-type LysRS, whereas its tick and mammalian hosts would be expected to contain a class II-type protein. To investigate the utility of the class I LysRS as a diagnostic target for Lyme disease, the corresponding gene (lysK) was cloned and sequenced from B. afzelii, B. garinii, and B. hermsii. These lysK sequences were then used to design a primer set that could detect and genotype B. burgdorferi sensu strictu, B. afzelii, and B. garinii in one single polymerase chain reaction, while showing no cross reactivity with examples of other Borrelia or spirochetes.