Characterization of two newly isolated bacteriophages PW2 and PW4 and derived endolysins with lysis activity against Bacillus cereus group strains

ABSTRACT Bacillus anthracis is nonhemolytic, even though it is closely related to the highly hemolytic Bacillus cereus. Hemolysis by B. cereus results largely from the action of phosphatidylcholine-specific phospholipase C (PC-PLC) and sphingomyelinase (SPH), encoded by the plc and sph genes, respectively. In B. cereus, these genes are organized in an operon regulated by the global regulator PlcR. B. anthracis contains a highly similar cereolysin operon, but it is transcriptionally silent because the B. anthracis PlcR is truncated at the C terminus. Here we report the cloning, expression, purification, and enzymatic characterization of PC-PLC and SPH from B. cereus and B. anthracis. We also investigated the effects of expressing PlcR on the expression of plc and sph. In B. cereus, PlcR was found to be a positive regulator of plc but a negative regulator of sph. Replacement of the B. cereus plcR gene by its truncated orthologue from B. anthracis eliminated the activities of both PC-PLC and SPH, whereas introduction into B. anthracis of the B. cereus plcR gene with its own promoter did not activate cereolysin expression. Hemolytic activity was detected in B. anthracis strains containing the B. cereus plcR gene on a multicopy plasmid under control of the strong B. anthracis protective antigen gene promoter or in a strain carrying a multicopy plasmid containing the entire B. cereus plc-sph operon. Slight hemolysis and PC-PLC activation were found when PlcR-producing B. anthracis strains were grown under anaerobic-plus-CO2 or especially under aerobic-plus-CO2 conditions. Unmodified parental B. anthracis strains did not demonstrate obvious hemolysis under the same conditions.

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Phenotypic and Genotypic Characterization of the New Bacillus Cereus Phage SWEP1

10.21203/rs.3.rs-522035/v1 ◽

2021 ◽

Author(s):

Chujin Ruan ◽

Xinyao Niu ◽

Guangzhou Xiong ◽

GuoWei Chen ◽

Hanqing Wu ◽

...

Keyword(s):

Bacillus Cereus ◽

Burst Size ◽

Black Soil ◽

Genotypic Characterization ◽

Lysis Activity ◽

Query Coverage ◽

Host Lysis ◽

Comparative Genomics Analysis ◽

Phenotypic And Genotypic Characterization

Abstract A new Bacillus cereus phage SWEP1 was isolated from black soil. The host lysis activity of phage SWEP1 has a relatively short latent time (20 min) and a small burst size of 83 PFU. The genome of SWEP1 consists of 162,461 bp with 37.77% G+C content. The phage encodes 278 predicted proteins where 103 were assigned functionally. No tRNA gene was found. Comparative genomics analysis indicated that SWEP1 is related to Bacillus phage B4 (86.91% identity, 90% query coverage). Phenotypic and genotypic characterization suggesting that SWEP1 is a new member of a new species in the genus Bequatrovirus, family Herelleviridae.

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Characterization of a spore-specific protein of the Bacillus cereus group

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.2012.02562.x ◽

2012 ◽

Vol 331 (2) ◽

pp. 152-159

Author(s):

Cecilie From ◽

Menno Voort ◽

Tjakko Abee ◽

Per Einar Granum

Keyword(s):

Bacillus Cereus ◽

Specific Protein ◽

Bacillus Cereus Group

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Prevalence and characterization of Bacillus cereus group from various marketed dairy products in India

Dairy Science and Technology ◽

10.1007/s13594-014-0174-5 ◽

2014 ◽

Vol 94 (5) ◽

pp. 483-497 ◽

Cited By ~ 22

Author(s):

Sarita Kumari ◽

Prabir K. Sarkar

Keyword(s):

Bacillus Cereus ◽

Dairy Products ◽

Bacillus Cereus Group

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Incidence and characterisation of Bacillus cereus bacteriophages from Thua Nao, a Thai fermented soybean product

BioMolecular Concepts ◽

10.1515/bmc-2021-0009 ◽

2021 ◽

Vol 12 (1) ◽

pp. 85-93

Author(s):

Wallapat Phongtang ◽

Ekachai Chukeatirote

Keyword(s):

Bacillus Cereus ◽

Food Industry ◽

Pathogenic Bacteria ◽

Morphological Analysis ◽

Food Poisoning ◽

Fermented Soybean ◽

Foodborne Pathogenic Bacteria ◽

Ph Range ◽

Potential Use

Abstract Bacillus cereus is considered to be an important food poisoning agent causing diarrhea and vomiting. In this study, the occurrence of B. cereus bacteriophages in Thai fermented soybean products (Thua Nao) was studied using five B. cereus sensu lato indicator strains (four B. cereus strains and one B. thuringiensis strain). In a total of 26 Thua Nao samples, there were only two bacteriophages namely BaceFT01 and BaceCM02 exhibiting lytic activity against B. cereus. Morphological analysis revealed that these two bacteriophages belonged to the Myoviridae. Both phages were specific to B. cereus and not able to lyse other tested bacteria including B. licheniformis and B. subtilis. The two phages were able to survive in a pH range between 5 and 12. However, both phages were inactive either by treatment of 50°C for 2 h or exposure of UV for 2 h. It should be noted that both phages were chloroform-insensitive, however. This is the first report describing the presence of bacteriophages in Thua Nao products. The characterization of these two phages is expected to be useful in the food industry for an alternative strategy including the potential use of the phages as a biocontrol candidate against foodborne pathogenic bacteria.

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