Molecular Systematics of the Entomopathogenic Bacteria Bacillus popilliae, Bacillus lentimorbus, and Bacillus sphaericus
MetadataShow full item record
Using a combination of two PCR primer pairs, the cry18Aa1 gene was detected in 31 of 35 B. popilliae isolates and in 1 of 18 B. lentimorbus isolates. When hemolymph smears were examined microscopically, a parasporal crystal was seen in three of the four B. popilliae strains where the PCR primers could not amplify the paraspore gene. The fourth strain was not tested due to the unavailability of infected hemolymph. A paraspore was also detected by microscopic examination in a subgroup of 14 B. lentimorbus strains. In combination, the primer pairs CryBp1 and CryBp2 are effective at detecting the paraspore gene in B. popilliae isolates, but not in the B. lentimorbus isolates. Growth in media supplemented with 2% NaCl was found to be less reliable in distinguishing the species than was vancomycin resistance, the latter present only in B. popilliae.
The basis for vancomycin resistance in all isolates was investigated using a polymerase chain reaction assay designed to amplify the vanB gene in enterococci. An amplicon was identified and sequenced. The amplified portion of the putative ligase gene in B. popilliae had 77% and 68-69% nucleotide identity to the sequences of the vanA gene and the vanB genes, respectively. There was 75% and 69-70% identity between the deduced amino acid sequence of the putative ligase gene in B. popilliae and the deduced amino acid sequence of the vanA gene and the vanB genes, respectively. It has been determined that the vanE gene is located either on a plasmid greater than 16 kb in size or on the chromosome. The gene in B. popilliae may have had an ancestral gene in common with vancomycin resistance genes in enterococci.
Bacillus sphaericus strains isolated on the basis of pathogenicity for mosquito larvae and strains isolated on the basis of a reaction with a B. sphaericus DNA homology group IIA 16S rRNA probe were analyzed for DNA similarity. All of the pathogens belonged to homology group IIA, but this group also contained nonpathogens. It appears inappropriate to designate this homology group a species based solely upon pathogenicity.
- Doctoral Dissertations 
Showing items related by title, author, creator and subject.
HtrC Is Involved in Proteolysis of YpeB during Germination of Bacillus anthracis and Bacillus subtilis Spores Bernhards, Casey B.; Chen, Yan; Toutkoushian, Hannah; Popham, David L. (American Society for Microbiology, 2014-11-10)Bacterial endospores can remain dormant for decades yet can respond to nutrients, germinate, and resume growth within minutes. An essential step in the germination process is degradation of the spore cortex peptidoglycan ...
Lambert, Emily Anne (Virginia Tech, 2010-03-24)Bacillus anthracis is a spore-forming bacterium that is included on the list of select agents compiled by the Centers for Disease Control. When a B. anthracis spore germinates, a protective layer of peptidoglycan known as ...
Bacterial endophytes: Bacillus spp. from annual crops as potential biological control agents of black pod rot of cacao Melnick, Rachel L.; Zidack, N.K.; Bailey, B.A.; Maximova, S.N.; Guiltinan, M.; Backman, Paul A.This study examines methods to reduce black pod rot in cacao plants.