The classification of pseudomonads and other obligately aerobic gram-negative bacteria from british pork sausage and ingredients

Abstract

On the basis of a computer analysis of 126 characters for each of 20 stock cultures and 165 isolates of Gram-negative, aerobic bacteria from fresh and processed pork, 138 isolates were identified with Pseudomonas. These were separated into 5 major clusters and 1 minor group. Twelve isolates were identified with Moraxella, 4 with Alteromonas and 11 were left unassigned. The identification of 101 isolates with Pseudomonas fragi provides substantive evidence that this species is the principal aerobic, Gram-negative contaminant of freshly butchered, stored or processed pork. Fluorescent pseudomonads were minor contaminants; 13 of our isolates were identified with Pseudomonas fluorescens biotype A, 8 with biotype C and 16 tentatively with biotype G. A simple determinative key for the routine identification of these organisms is given.