Effect of temperature, pH, and water activity on biofilm formation by Salmonella Enterica enteritidis PT4 on stainless steel surfaces as indicated by the bead vortexing method and conductance measurements

dc.contributor.author	Giaouris, E	en
dc.contributor.author	Chorianopoulos, N	en
dc.contributor.author	Nychas, G-JE	en
dc.date.accessioned	2014-06-06T06:46:30Z
dc.date.available	2014-06-06T06:46:30Z
dc.date.issued	2005	en
dc.identifier.issn	0362028X	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/3042
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-26644446699&partnerID=40&md5=ab8494497f5aab5b21751e8308f4c218	en
dc.subject.other	sodium chloride	en
dc.subject.other	stainless steel	en
dc.subject.other	water	en
dc.subject.other	article	en
dc.subject.other	bacterium adherence	en
dc.subject.other	biofilm	en
dc.subject.other	dose response	en
dc.subject.other	food contamination	en
dc.subject.other	food control	en
dc.subject.other	food industry	en
dc.subject.other	growth, development and aging	en
dc.subject.other	metabolism	en
dc.subject.other	methodology	en
dc.subject.other	pH	en
dc.subject.other	physiology	en
dc.subject.other	Salmonella enteritidis	en
dc.subject.other	standard	en
dc.subject.other	temperature	en
dc.subject.other	time	en
dc.subject.other	Bacterial Adhesion	en
dc.subject.other	Biofilms	en
dc.subject.other	Dose-Response Relationship, Drug	en
dc.subject.other	Food Contamination	en
dc.subject.other	Food Microbiology	en
dc.subject.other	Food-Processing Industry	en
dc.subject.other	Hydrogen-Ion Concentration	en
dc.subject.other	Salmonella enteritidis	en
dc.subject.other	Sodium Chloride	en
dc.subject.other	Stainless Steel	en
dc.subject.other	Temperature	en
dc.subject.other	Time Factors	en
dc.subject.other	Water	en
dc.subject.other	Bacteria (microorganisms)	en
dc.subject.other	Enteritidis	en
dc.subject.other	Salmonella enterica	en
dc.subject.other	Salmonella enteritidis	en
dc.title	Effect of temperature, pH, and water activity on biofilm formation by Salmonella Enterica enteritidis PT4 on stainless steel surfaces as indicated by the bead vortexing method and conductance measurements	en
heal.type	journalArticle	en
heal.publicationDate	2005	en
heal.abstract	An assay was developed in an effort to elucidate the effect of important environmental parameters (temperature, pH, and water activity [aw]) on Salmonella Enteritidis biofilm formation on stainless steel surfaces. To achieve this, a modified microbiological technique used for biofilm studying (the bead vortexing method) and a rapid method based on conductivity measurements were used. The ability of the microorganism to generate biofilm on the stainless surfaces was studied at three temperatures (5, 20, and 37°C), four pH values (4.5, 5.5, 6.5, and 7.4), and four aw values (0.5, 1.5, 5.5, and 10.5% NaCl). Results obtained by the bead vortexing method show that maximum numbers of adherent bacteria per square centimeter (106 CFU/cm2) were attained in 6 days at 20°C. Biofilm formation after 7 days of incubation at 20°C was found to be independent of the pH value. In addition, the high concentration of sodium chloride (10.5% NaCl, a w = 0.94) clearly inhibited the adherence of cells to the coupons. Conductance measurements were used as a supplementary tool to measure indirectly the attachment and biofilm formation of bacterial cells on stainless steel surfaces via their metabolic activity (i.e., changes in the conductance of the growth medium due to microbial growth or metabolism). Results obtained by conductance measurements corresponded well to those of the bead vortexing method. Furthermore, we were able to detect cells that remained attached on the metal surfaces even after vortexing via their metabolic activity. The results, except for demonstrating environmental-dependent Salmonella Enteritidis biofilm formation, indicated that traditional vortexing with beads did not remove completely biofilm cells from stainless steel; hence, conductance measurements seem to provide a more sensitive test capable to detect down to one single viable organism. Copyright ©, International Association for Food Protection.	en
heal.journalName	Journal of Food Protection	en
dc.identifier.issue	10	en
dc.identifier.volume	68	en
dc.identifier.spage	2149	en
dc.identifier.epage	2154	en