Psychrotrophic flora of raw milk: resistance to several common disinfectants.
The psychrotrophic bacterial flora of milk was examined after aseptic hand milking. A total of 409 strains were tentatively characterized and classified into 17 groups by a reduced set of tests and cluster analysis. Lipolytic organisms (53.7% exceeded proteolytic organisms (29.6%), and a reported predominance of oxidase-positive organisms (54.5%) was not found. Gram-negatives were mainly Enterobacteriaceae, Flavobacterium, Acinetobacter and Pseudomonas. In the Gram-positive groups Micrococcaceae were the most abundant (44.4%) followed by coryneforms (16.3%). Only two of seven commonly used disinfectants acted differently with Gram-positive and Gram-negative organisms (P less than 0.01), although in general Gram-positives were more resistant than Gram-negatives.
Suárez
B
B
Centro de Investigaciones Agrarias de Mabegondo, La Coruña, Spain.
Ferreirós
C M
CM
D000818:Animals; D002417:Cattle; D004202:Disinfectants / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D006090:Gram-Negative Bacteria / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D008892:Milk / Q000382:microbiology*
D004202:Disinfectants