Estimation of gram-negative bacteria in milk: a comparison of inhibitor systems for preventing gram-positive bacterial growth.
A number of inhibitor systems which have been reported to allow selection of Gram-negative bacteria were tested against Gram-positive and Gram-negative isolates of dairy origin. No one system worked perfectly. A mixture of crystal violet-penicillin-nisin or monensin had least inhibitory effect on Gram-negative isolates whereas Selectocult (a commercially available mixture of Benzalkon A 50% and crystal violet) and sodium deoxycholate were the most effective inhibitors of Gram-positive bacteria. Cetrimide-fucidin-cephaloridine solutions, which have been reported as allowing selective growth of pseudomonads, were not so specific when applied to milk systems.
D000818:Animals; D001548:Benzalkonium Compounds / Q000494:pharmacology; D002417:Cattle; D002509:Cephaloridine / Q000494:pharmacology; D002593:Cetrimonium Compounds / Q000494:pharmacology; D003840:Deoxycholic Acid / Q000494:pharmacology; D005672:Fusidic Acid / Q000494:pharmacology; D005840:Gentian Violet / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development*; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development*; D006131:Growth Inhibitors / Q000494:pharmacology*; D008892:Milk / Q000382:microbiology*; D008985:Monensin / Q000494:pharmacology; D009561:Nisin / Q000494:pharmacology; D010406:Penicillins / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000494:pharmacology
D001548:Benzalkonium Compounds; D002593:Cetrimonium Compounds; D006131:Growth Inhibitors; D010406:Penicillins; D013778:Tetrazolium Salts; D003840:Deoxycholic Acid; D009561:Nisin; C011314:neotetrazolium; D005672:Fusidic Acid; D008985:Monensin; D005840:Gentian Violet; D002509:Cephaloridine