Controlling Bacillus cereus adherence to stainless steel with different cleaning and sanitizing procedures used in dairy plants

Abstract

RESUMOFoi observada a adesão de Bacillus cereus em superfície de aço inoxidável em contato com o leite, segundo o procedimento de limpeza, a sanitização e as propriedades físico-químicas da superfície. O número de B. cereus viáveis, após os procedimentos de higienização, foi afetado pela temperatura, pela concentração das soluções alcalinas e ácidas e pelo pH da solução clorada. A adesão de B. cereus em aço inoxidável não foi termodinamicamente favorável, e ocorreu pouca adesão desse microrganismo, de acordo com os aspectos termodinâmicos da adesão.Palavras-chave: Bacillus cereus, equipamento, indústria do leite, higienização

Hydrophobicity and specific biofilm features of Bacillus cereus spores subjected to pH stresses

“…Spores of B. cereus are generally recognized to be hydrophobic or highly hydrophobic (Simmonds et al, 2003;Tauveron et al, 2006, Ankelokar andLabbé, 2010). Hydrophilic spores have already been reported among strains of B. cereus isolated in the dairy environment Salustiano et al, 2010), and strains of thermophilic bacilli isolated from milk powder (Seale et al, 2008). Accordingly, the dairy environment appeared to be a source of hydrophilic spores of both mesophilic and thermophilic bacilli.…”

“…Nevertheless, adaptation of dairy-associated B. cereus to alkaline pH was previously reported (Lindsay et al, 2002). Hydrophilic strains of this bacterium were isolated in the dairy industry from CIP solutions (Salustiano et al, 2010) or the filling machine . Since CIP systems, are mainly alkaline and/or acidic washes often performed at high temperature (Bremer et al, 2006), the existence of a relationship between the hydrophilic character of B. cereus spore surfaces and alkali adaptation is believed.…”

Microbiological contamination of surfaces in fish industry

“…The failure in fully following the SOHPs, at all times of hygienization, may lead to a variation in microbial counts, which may then compromise the hygienic-sanitary quality of foods (Kahraman et al, 2010;Salustiano et al, 2010). The high microbial load found in some of the equipment and utensils analyzed (Table 2) and the significantly higher levels of aerobic mesophile contamination in all samples collected in the afternoon shift, in both collection periods, are attributed to inefficient cleaning.…”

“…Salustiano et al (2010) assessed post-pasteurization recontamination of milk by Bacillus cereus using automated ribotyping. Seven ribogroups were identified and the same ribogroup was isolated from four surfaces and milk samples, suggesting the surfaces are repositories of that species.…”

“…Dirt particles and microorganisms that fail to be removed by correct hygienization procedures may start adhesion processes and lead to the formation of biofilms (Andrade, 2008;Salustiano et al, 2010).…”