Genotyping and Toxigenic Potential ofBacillus subtilisandBacillus pumilusStrains Occurring in Industrial and Artisanal Cured Sausages

Abstract

Artisanal and industrial sausages were analyzed for their aerobic, heat-resistant microflora to assess whether new emerging pathogens could be present among Bacillus strains naturally contaminating cured meat products. Sixty-four isolates were characterized by randomly amplified polymorphic DNA (RAPD)-PCR and fluorescent amplified fragment length polymorphism (fAFLP). The biotypes, identified by partial 16S rRNA gene sequence analysis, belonged to Bacillus subtilis, Bacillus pumilus, and Bacillus amyloliquefaciens species. Both RAPD-PCR and fAFLP analyses demonstrated that a high genetic heterogeneity is present in the B. subtilis group even in strains harvested from the same source, making it possible to isolate 56 different biotypes. Moreover, fAFLP analysis made it possible to distinguish B. subtilis from B. pumilus strains. The strains were characterized for their toxigenic potential by molecular, physiological, and immunological techniques. Specific PCR analyses revealed the absence of DNA sequences related to HBL, BcET, NHE, and entFM Bacillus cereus enterotoxins and the enzymes sphingomyelinase Sph and phospholipase PI-PLC in all strains; also, the immunological analyses showed that Bacillus strains did not react with NHE-and HBL-specific antibodies. However, some isolates were found to be positive for hemolytic and lecithinase activity. The absence of toxigenic potential in Bacillus strains from the sausages analyzed indicates that these products can be considered safe under the processing conditions they were produced; however, great care should be taken when the ripening time is shortened, particularly in the case of traditional sausages, which could contain high amounts of Bacillus strains and possibly some B. cereus cells.

Rapid Identification of Polyhydroxyalkanoate Accumulating Members of Bacillales Using Internal Primers forphaCGene ofBacillus megaterium

“…PCR based randomly amplified polymorphic DNA (RAPD) technique has been used for molecular typing and identification among closely related species of the genus Bacillus [30,31]. The pattern of amplified DNA fragments produce during RAPD-PCR provides information on genetic variability between organisms of different species.…”

“…Large variations and inconsistencies in test results make the identification of this species difficult. In the light of this, several methods have been employed for identification of strains of B. megaterium such as DNA-DNA hybridization [26], analysis of cellular fatty acid content [27], small-subunit-ribosomal RNA sequencing [20,28], 16S rDNA sequencing [29], randomly amplified polymorphic DNA (RAPD) techniques [30,31], SDS-PAGE of whole cell protein profiles [32], and PHA inclusion body associated protein profiles [27]. However, these methods are laborious, time consuming and have to be used in combinations.…”

Determination of Toxigenic Potentials of Bacillus Strains Isolated from Okpehe, a Nigerian Fermented Condiment

“…There is a dearth of information about the epidemiology of bacilli food borne diseases in Nigeria, but diseases from non-B. cereus bacilli have been reported to be generally low (Matarante et al 2004). The market samples of okpehe produced spontaneously could be referred to as a safe product, since the toxin was not detected from the product tested using the BCET-RPLA enterotoxin detection kit.…”

Purification and characterization of β $$ \boldsymbol{\upbeta} $$ -mannanase from Bacillus pumilus (M27) and its applications in some fruit juices

“…Due to their ability to form spores, these microorganisms continue their vital functions in the process of preparation of many foods (milk and fruit juice pasteurization, packaging, etc.). A few strain belonging to this genus (B. licheniformis, B. subtilis, B. thuringiensis and B. pumilus) are commonly found in meat and meat products and traditional European sausages, but making food-borne disease incidence is low (Drobniewski 1993;Matarante et al 2004;Yamanaka et al 2007). The many species within the genus Bacillus are potential to secrete some extracellular enzymes such as high amylase, proteases, xylanases and cellulases.…”