A Frequency Matrix for Probabilistic Identification of Some Bacilli

Priest, Fergus G.; Alexander, Brian

doi:10.1099/00221287-134-11-3011

Cited by 21 publications

(21 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The scores obtained with this matrix were acceptable, being well within the limits for identification scores set in other studies (e.g. Williams et al, 1985;Priest & Alexander, 1988). It is anticipated that this matrix will be particularly useful when identifying restricted selections of strains recovered, for example, from selective isolation plates or diseased insects.…”

Section: Discussionsupporting

confidence: 50%

See 1 more Smart Citation

Numerical classification and identification of Bacillus sphaericus including some strains pathogenic for mosquito larvae

Alexander

Priest

1990

Journal of General Microbiology

Self Cite

View full text Add to dashboard Cite

Ninety-one strains of Baciffus sphaericus, including representatives of all the established DNA homology group, related round-spored and oval-spored species, and six strains pathogenic for mosquito larvae, were examined for 155 characters. Numerical analyses (Jaccard coefficient/average linkage clustering) based on the 88 variable features revealed 14 clusters at the 79 yo similarity level that contained more than one strain and 17 single member clusters. All insect pathogenic strains were recovered in a single cluster and the classification was in accord with an established classification based on DNA sequence homology. Two frequency matrices for probabilistic identification were constructed and tested. A comprehensive matrix comprising 14 mesophilic, round-spored taxa and 27 tests gave good results for identification of hypothetical median organisms, cluster overlap and identifications of representative strains (based on data generated in the classification study). Reference strains for the 14 taxa and eight additional insect pathogenic strains were examined for the 27 tests and were correctly identified with high scores using this matrix. A second matrix comprising seven taxa and 13 tests also performed well in the theoretical evaluation and correctly identified the reference strains and insect pathogenic strains.

show abstract

Section: Discussionsupporting

confidence: 50%

“…Test results were redetermined for cluster representatives and some additional strains, which were identified using MATIDEN (Sneath, 1979~). Use of these programs has been described previously (Priest & Alexander, 1988).…”

Section: Methodsmentioning

confidence: 99%

Numerical classification and identification of Bacillus sphaericus including some strains pathogenic for mosquito larvae

Alexander

Priest

1990

Journal of General Microbiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…This group comprises the six species B. cereus, Bacillus mycoides, Bacillus pseudomycoides, Bacillus thuringiensis, Bacillus weihenstephanensis and Bacillus anthracis (Gordon et al, 1973;Lechner et al, 1998;Priest et al, 1988;Turnbull & Kramer 1991). While a high degree of diversity concerning the virulence factors is found, a close genetic relationship has been observed between all species of the B. cereus group (Helgason et al, 2000a).…”

Section: Introductionmentioning

confidence: 99%

Emetic toxin formation of Bacillus cereus is restricted to a single evolutionary lineage of closely related strains

Svensson²,

et al. 2005

View full text Add to dashboard Cite

An in-depth polyphasic approach was applied to study the population structure of the human pathogen Bacillus cereus. To assess the intraspecific biodiversity of this species, which is the causative agent of gastrointestinal diseases, a total of 90 isolates from diverse geographical origin were studied by genetic [M13-PCR, random amplification of polymorphic DNA (RAPD), multilocus sequence typing (MLST)] and phenetic [Fourier transform Infrared (FTIR), protein profiling, biochemical assays] methods. The strain set included clinical strains, isolates from food remnants connected to outbreaks, as well as isolates from diverse food environments with a well documented strain history. The phenotypic and genotypic analysis of the compiled panel of strains illustrated a considerable diversity among B. cereus connected to diarrhoeal syndrome and other non-emetic food strains, but a very low diversity among emetic isolates. Using all typing methods, cluster analysis revealed a single, distinct cluster of emetic B. cereus strains. The isolates belonging to this cluster were neither able to degrade starch nor could they ferment salicin; they did not possess the genes encoding haemolysin BL (Hbl) and showed only weak or no haemolysis. In contrast, haemolytic-enterotoxin-producing B. cereus strains showed a high degree of heterogeneity and were scattered over different clusters when different typing methods were applied. These data provide evidence for a clonal population structure of cereulide-producing emetic B. cereus and indicate that emetic strains represent a highly clonal complex within a potentially panmictic or weakly clonal background population structure of the species. It may have originated only recently through acquisition of specific virulence factors such as the cereulide synthetase gene.Abbreviations: FTIR, Fourier transform Infrared; Hbl, haemolysin BL; MLST, multilocus sequence typing; Nhe, non-haemolytic enterotoxin; RAPD, random amplification of polymorphic DNA.The GenBank/EMBL/DDBJ accession numbers for the sequences of the internal gene fragments used for MLST and for the sporulation stage III AB genes reported in this paper are AY762151-AY762213 and AY578317-AY578349, respectively.

show abstract

“…Based on their high similarity, it has been repeatedly proposed that all species of the B. c~'reus group be merged into a single species (1, 2, 7, 26,39,40). It is suggested, however, that there are good reasons, in spite of the close relationship of the species, to maintain the taxonomy of the B. cereus group at the species level.…”

mentioning

confidence: 99%

Bacillus weihenstephanensis sp. nov. is a new psychrotolerant species of the Bacillus cereus group

Lechner

Mayr

Francis

et al. 1998

International Journal of Systematic Bacteriology

389

324

View full text Add to dashboard Cite

The Bacillus cereus group comprises the four valid species Bacillus cereus, Bacillus mycoides, Bacillus fhuringiensis and Bacillus anthracis. Some isolates of B. cereus are known to be psychrotolerant (growth a t 7 O C or below). Here, specific sequence differences are described between the 165 rDNA, the 235 rDNA, the 165-235 rDNA spacer region and the genes of the major cold-shock protein homologue cspA in a variety of psychrotolerant and mesophilic B. cereus and B. mycoides strains. Randomly amplified polymorphic DNA analysis using three different primers clearly separated psychrotolerant strains of both species from the rest of the B. cereus group, as did inverse PCR patterns of the rDNA operons. These data strongly support a hitherto unrecognized fifth sub-group within the B. cereus species group comprising psychrotolerant, but not mesophilic, B. cereus strains. Despite the latter finding, the DNA sequences investigated exhibited a high degree of sequence similarity indicating a close relationship between the species of the B. cereus group. Considering the unusual importance of B. cereus in both food poisoning and food spoilage and to avoid merging all species of the group, a new species, Bacillus weihenstephanensis sp. nov., comprising psychrotolerant 'cereus' strains, is proposed. Isolates of the new species grow a t 4-7 "C but not a t 43 OC and can be identified rapidly using rDNA or cspA targeted PCR. The type strain is B. weihenstephanensis WSBC 10204T (= DSM 1182IT).

show abstract

A Frequency Matrix for Probabilistic Identification of Some Bacilli

Cited by 21 publications

References 27 publications

Numerical classification and identification of Bacillus sphaericus including some strains pathogenic for mosquito larvae

Numerical classification and identification of Bacillus sphaericus including some strains pathogenic for mosquito larvae

Emetic toxin formation of Bacillus cereus is restricted to a single evolutionary lineage of closely related strains

Bacillus weihenstephanensis sp. nov. is a new psychrotolerant species of the Bacillus cereus group

Contact Info

Product

Resources

About