Prevalence, virulence genes, and genetic diversity of Bacillus cereus isolated from convenience food [pdf]

Members of Bacillus cereus group are important food contaminants and they are of relevant interest in food safety and public heath due to their ability to cause two distinct forms of food poisoning, emetic and diarrhoeal syndrome. In the present study, 90 strains of B. cereus isolated from dairy products, have been typed using Multilocus Sequence Typing (MLST) analysis and investigated for the occurrence of 10 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, entS and bceT) and one emetogenic gene (ces), to determine their genetic diversity. A total of 58 sequence types were identified and among these 17 were signalled as new profiles. Among the virulence genes, the majority of our strains carried the entS (92%), entFM (86%), nhe (82%) and cytK (72%) genes. All remaining genes were identified in at least one strain with different prevalence, stressing the genetic diversity, how even the different grade of pathogenicity of B. cereus isolated from dairy products.

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Corrigendum: Bacillus cereus Isolated From Vegetables in China: Incidence, Genetic Diversity, Virulence Genes, and Antimicrobial Resistance

Frontiers in Microbiology ◽

10.3389/fmicb.2020.00848 ◽

2020 ◽

Vol 11 ◽

Author(s):

Pengfei Yu ◽

Shubo Yu ◽

Juan Wang ◽

Hui Guo ◽

Ying Zhang ◽

...

Keyword(s):

Genetic Diversity ◽

Antimicrobial Resistance ◽

Bacillus Cereus ◽

Virulence Genes

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Bacillus cereus Isolated From Vegetables in China: Incidence, Genetic Diversity, Virulence Genes, and Antimicrobial Resistance

Frontiers in Microbiology ◽

10.3389/fmicb.2019.00948 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 9

Author(s):

Pengfei Yu ◽

Shubo Yu ◽

Juan Wang ◽

Hui Guo ◽

Ying Zhang ◽

...

Keyword(s):

Genetic Diversity ◽

Antimicrobial Resistance ◽

Bacillus Cereus ◽

Virulence Genes

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Genetic diversity and virulence genes in Streptococcus uberis strains isolated from bovine mastitis

Semina Ciências Agrárias ◽

10.5433/1679-0359.2017v38n4suplp2595 ◽

2017 ◽

Vol 38 (4Supl1) ◽

pp. 2595 ◽

Cited By ~ 3

Author(s):

Rafael Ambrósio Loures ◽

Ulisses De Pádua Pereira ◽

Glei Dos Anjos de Carvalho-Castro ◽

Gláucia Frasnelli Mian ◽

Dircéia Aparecida da Costa Custódio ◽

...

Keyword(s):

Genetic Diversity ◽

Virulence Genes ◽

Mammary Epithelial Cells ◽

Bovine Mastitis ◽

Mammary Epithelial ◽

Molecular Characteristics ◽

Dairy Herds ◽

High Genetic Diversity ◽

Streptococcus Uberis ◽

Intensively Managed

Mastitis is one of the most common and costly infectious diseases in dairy cattle worldwide. This is a multifactorial illness caused by different microorganisms, including virus, yeasts, algae, parasites, and several species of bacteria. Among these bacteria, Streptococcus uberis is an important environmental pathogen that is responsible for a large range of clinical and subclinical mammary infections, especially in intensively managed herds. Despite the increasing importance of this pathogen in the etiology of bovine mastitis, data on its virulence and diversity in Brazilian dairy herds are scarce. The aims of the present study were to investigate the virulence characteristics of S. uberis isolated from bovine mastitis and to assess the molecular epidemiology of the Brazilian isolates using pulsed-field gel electrophoresis (PFGE). In this work, 46 strains of S. uberis isolated from bovine mastitis from 26 Brazilian dairy herds were evaluated regarding their genetic diversity by PFGE using with the SmaI enzyme. Additionally, the presence of the virulence genes skc and pauA, which encode plasminogen activators, and the gene sua, which encodes an adhesion molecule in mammary epithelial cells, were assessed by PCR. Our results showed a high genetic diversity in the population, displaying many different patterns in the PFGE analysis. A high proportion of strains was positive for virulence genes in the sampled population (sua [100%], pauA [91%], and skc [91%]). The high frequency of skc, pauA, and sua genes among the studied strains suggests the importance of these virulence factors, possibly helping S. uberis in the colonization of the bovine mammary gland. Surveys of the genetic and molecular characteristics of this pathogen can improve our knowledge of bacterial activity and identify molecules that have roles in the establishment of the infection. This might help in the development of more effective measures to control and prevent bovine mastitis.

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Expression of Bacillus cereus Virulence-Related Genes in an Ocular Infection-Related Environment

Microorganisms ◽

10.3390/microorganisms8040607 ◽

2020 ◽

Vol 8 (4) ◽

pp. 607 ◽

Cited By ~ 1

Author(s):

Phillip S. Coburn ◽

Frederick C. Miller ◽

Morgan A. Enty ◽

Craig Land ◽

Austin L. LaGrow ◽

...

Keyword(s):

Bacillus Cereus ◽

Virulence Genes ◽

Ex Vivo ◽

Brain Heart Infusion ◽

Luria Bertani ◽

Ocular Infection ◽

Rna Seq ◽

Specific Factors ◽

Low Levels

Bacillus cereus produces many factors linked to pathogenesis and is recognized for causing gastrointestinal toxemia and infections. B. cereus also causes a fulminant and often blinding intraocular infection called endophthalmitis. We reported that the PlcR/PapR system regulates intraocular virulence, but the specific factors that contribute to B. cereus virulence in the eye remain elusive. Here, we compared gene expression in ex vivo vitreous humor with expression in Luria Bertani (LB) and Brain Heart Infusion (BHI) broth by RNA-Seq. The expression of several cytolytic toxins in vitreous was less than or similar to levels observed in BHI or LB. Regulators of virulence genes, including PlcR/PapR, were expressed in vitreous. PlcR/PapR was expressed at low levels, though we reported that PlcR-deficient B. cereus was attenuated in the eye. Chemotaxis and motility genes were expressed at similar levels in LB and BHI, but at low to undetectable levels in vitreous, although motility is an important phenotype for B. cereus in the eye. Superoxide dismutase, a potential inhibitor of neutrophil activity in the eye during infection, was the most highly expressed gene in vitreous. Genes previously reported to be important to intraocular virulence were expressed at low levels in vitreous under these conditions, possibly because in vivo cues are required for higher level expression. Genes expressed in vitreous may contribute to the unique virulence of B. cereus endophthalmitis, and future analysis of the B. cereus virulome in the eye will identify those expressed in vivo, which could potentially be targeted to arrest virulence.

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