Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-3-30
pubmed:abstractText
This report describes the adaptation of an in situ direct viable count (in situ DVC) method in biofilm disinfection studies. The results obtained with this technique were compared to two other enumeration methods, the plate count (PC) and conventional direct viable count (c-DVC). An environmental isolate (Klebsiella pneumoniae Kp1) was used to form biofilms on stainless steel coupons in a stirred batch reactor. The in situ DVC method was applied to directly assess the viability of bacteria in biofilms without disturbing the integrity of the interfacial community. As additional advantages, the results were observed after 4 h instead of the 24 h incubation time required for colony formation and total cell numbers that remained on the substratum were enumerated. Chlorine and monochloramine were used to determine the susceptibilities of attached and planktonic bacteria to disinfection treatment using this novel analytical approach. The planktonic cells in the reactor showed no significant change in susceptibility to disinfectants during the period of biofilm formation. In addition, the attached cells did not reveal any more resistance to disinfection than planktonic cells. The disinfection studies of young biofilms indicated that 0.25 mg/l free chlorine (at pH 7.2) and 1 mg/l monochloramine (at pH 9.0) have comparable disinfection efficiencies at 25 degrees C. Although being a weaker disinfectant, monochloramine was more effective in removing attached bacteria from the substratum than free chlorine. The in situ DVC method always showed at least one log higher viable cell densities than the PC method, suggesting that the in situ DVC method is more efficient in the enumeration of biofilm bacteria. The results also indicated that the in situ DVC method can provide more accurate information regarding the cell numbers and viability of bacteria within biofilms following disinfection.
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
S
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0167-7012
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NASA
pubmed:authorsComplete
Y
pubmed:pagination
167-80
pubmed:dateRevised
2007-7-17
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
A direct viable count method for the enumeration of attached bacteria and assessment of biofilm disinfection.
pubmed:affiliation
Department of Microbiology, Montana State University, Bozeman 59717.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't