Role of ribosidase in germination of Bacillus cereus T spores induced.

1985 ◽  
Vol 40 (3) ◽  
pp. 581-587 ◽  
Author(s):  
Hirofumi SHIBATA ◽  
Noriaki OHNISHI ◽  
Keiko TAKEDA ◽  
Isamu TANI
Keyword(s):  

1992 ◽  
Vol 6 (12) ◽  
pp. 1593-1604 ◽  
Author(s):  
Diana R. Wetmore ◽  
Sui-Lam Wong ◽  
Rodney S. Roche


2014 ◽  
Vol 80 (8) ◽  
pp. 2493-2503 ◽  
Author(s):  
Sara Esther Diomandé ◽  
Stéphanie Chamot ◽  
Vera Antolinos ◽  
Florian Vasai ◽  
Marie-Hélène Guinebretière ◽  
...  

ABSTRACTThe different strains ofBacillus cereuscan grow at temperatures covering a very diverse range. SomeB. cereusstrains can grow in chilled food and consequently cause food poisoning. We have identified a new sensor/regulator mechanism involved in low-temperatureB. cereusgrowth. Construction of a mutant of this two-component system enabled us to show that this system, called CasKR, is required for growth at the minimal temperature (Tmin). CasKR was also involved in optimal cold growth aboveTminand in cell survival belowTmin. Microscopic observation showed that CasKR plays a key role in cell shape during cold growth. Introducing thecasKRgenes in a ΔcasKRmutant restored its ability to grow atTmin. Although it was first identified in the ATCC 14579 model strain, this mechanism has been conserved in most strains of theB. cereusgroup. We show that the role of CasKR in cold growth is similar in otherB. cereus sensu latostrains with different growth temperature ranges, including psychrotolerant strains.



2006 ◽  
Vol 53 (4) ◽  
pp. 346-350 ◽  
Author(s):  
X. Lu ◽  
Y. Yuan ◽  
X.-L. Xue ◽  
G.-P. Zhang ◽  
S.-N. Zhou


2007 ◽  
Vol 74 (3) ◽  
pp. 850-860 ◽  
Author(s):  
Barbara Cardazzo ◽  
Enrico Negrisolo ◽  
Lisa Carraro ◽  
Leonardo Alberghini ◽  
Tomaso Patarnello ◽  
...  

ABSTRACT In the present study we characterized 47 food-borne isolates of Bacillus cereus using multilocus sequence typing (MLST). Newly determined sequences were combined with sequences available in public data banks in order to produce the largest data set possible. Phylogenetic analysis was performed on a total of 296 strains for which MLST sequence information is available, and three main lineages—I, II, and III—within the B. cereus complex were identified. With few exceptions, all food-borne isolates were in group I. The occurrence of horizontal gene transfer (HGT) among various strains was analyzed by several statistical methods, providing evidence of widespread lateral gene transfer within B. cereus. We also investigated the occurrence of toxin-encoding genes, focusing on their evolutionary history within B. cereus. Several patterns were identified, indicating a pivotal role of HGT in the evolution of toxin-encoding genes. Our results indicate that HGT is an important element in shaping the population structure of the B. cereus complex. The results presented here also provide strong evidence of reticulate evolution within the B. cereus complex.



2020 ◽  
Vol 43 (2) ◽  
pp. 250-253 ◽  
Author(s):  
Masataka Oda ◽  
Atsushi Yokotani ◽  
Naoki Hayashi ◽  
Go Kamoshida
Keyword(s):  


2008 ◽  
Vol 74 (8) ◽  
pp. 2370-2378 ◽  
Author(s):  
Maarten Mols ◽  
Tjakko Abee

ABSTRACT The presence and activities of urease genes were investigated in 49 clinical, food, and environmental Bacillus cereus isolates. Ten strains were shown to have urease genes, with eight of these strains showing growth on urea as the sole nitrogen source. Two of the urease-positive strains, including the sequenced strain ATCC 10987, could not use urea for growth, despite their capacities to produce active urease. These observations can be explained by the inability of the two strains to use ammonium as a nitrogen source. The impact of urea hydrolysis on acid stress resistance was subsequently assessed among the ureolytic B. cereus strains. However, none of the strains displayed increased fitness under acidic conditions or showed enhanced acid shock survival in the presence of urea. Expression analysis of urease genes in B. cereus ATCC 10987 revealed a low level of expression of these genes and a lack of pH-, nitrogen-, urea-, oxygen-, and growth phase-dependent modulation of mRNA transcription. This is in agreement with the low urease activity observed in strain ATCC 10987 and the other nine strains tested. Although a role for B. cereus ureolytic activity in acid survival cannot be excluded, its main role appears to be in nitrogen metabolism, where ammonium may be provided to the cells in nitrogen-limited, urea-containing environments.



1977 ◽  
Vol 130 (1) ◽  
pp. 242-248 ◽  
Author(s):  
J F Charba ◽  
H M Nakata
Keyword(s):  


1992 ◽  
Vol 38 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Sonia Senesi ◽  
Giulia Freer ◽  
Giovanna Batoni ◽  
Simona Barnini ◽  
Anna Capaccioli ◽  
...  

Spores of the strain NCIB 8122 of Bacillus cereus have been depleted of coats by treatment with 0.1% sodium dodecyl sulfate – 200 mM 2-mercaptoethanol – 0.5 M NaCl (pH 9.6). The coat-depleted spores did not show any decrease in viability, heat resistance, refractility, dipicolinic acid content, or specific activities of several protoplastic enzymes. The germinative response of the coat-depleted spores to adenosine and several analogues thereof was found qualitatively similar to that obtained with intact spores. However, germination kinetics appeared to be affected by coat removal, since germination rate measured as loss of refractility was eight times slower even at inducer concentrations 10-fold higher than those required to promote optimal germination response of intact spores. Loss of heat resistance, on the other hand, was hardly affected by coat removal. These results suggest that, even though spore coats are not essential for the triggering reaction, they are required for a rapid evolution of the later events in the germination process. Key words: adenosine analogues, germination-triggering reaction, spore coats, coat-depleted spores, Bacillus cereus.



1971 ◽  
Vol 34 (1) ◽  
pp. 12-15 ◽  
Author(s):  
H. U. Kim ◽  
J. M. Goepfert

One hundred seventy samples of dried food products in national distribution were examined for the incidence and level of contamination by Bacillus cereus. Twenty-five per cent of the samples yielded B. cereus at a level not exceeding 4000 per gram. Mannitol-egg yolk-polymyxin (MYP) agar was used as a presumptive test for the presence of B. cereus in the food samples. Various biochemical tests for the confirmation of suspicious colonies appearing on MYP agar were evaluated. A precipitin test employing spore precipitinogens was investigated as a confirmatory test for B. cereus. The possible role of B. cereus in outbreaks of foodborne disease in the United States is discussed.



2011 ◽  
Vol 77 (15) ◽  
pp. 5149-5156 ◽  
Author(s):  
Sara Salvetti ◽  
Karoline Faegri ◽  
Emilia Ghelardi ◽  
Anne-Brit Kolstø ◽  
Sonia Senesi

ABSTRACTBacillus cereuscan use swarming to move over and colonize solid surfaces in different environments. This kind of motility is a collective behavior accompanied by the production of long and hyperflagellate swarm cells. In this study, the genome-wide transcriptional response ofB. cereusATCC 14579 during swarming was analyzed. Swarming was shown to trigger the differential expression (>2-fold change) of 118 genes. Downregulated genes included those required for basic cellular metabolism. In accordance with the hyperflagellate phenotype of the swarm cell, genes encoding flagellin were overexpressed. Some genes associated with K+transport, phBC6A51 phage genes, and the binding component of the enterotoxin hemolysin BL (HBL) were also induced. Quantitative reverse transcription-PCR (qRT-PCR) experiments indicated an almost 2-fold upregulation of the entirehbloperon during swarming. Finally, BC1435 and BC1436, orthologs ofliaI-liaHthat are known to be involved in the resistance ofBacillus subtilisto daptomycin, were upregulated under swarming conditions. Accordingly, phenotypic assays showed reduced susceptibility of swarmingB. cereuscells to daptomycin, and Pspac-induced hyper-expression of these genes in liquid medium highlighted the role of BC1435 and BC1436 in the response ofB. cereusto daptomycin.



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