Occurrence of Klebsiella pneumoniae in Dairy Products

Abstract

From 165 dairy products with positive coliform counts on violet red bile agar, 410 of 607 colonies (67.5%) were confirmed as lactose fermenters in brilliant green bile broth with 24 h incubation at 35 C, Eighty-seven nonmotile isolates included 43 IMViC type − − + +, of which 38 were confirmed as Klebsiella pneumoniae. These 38 isolates originated from 25 products, 15.2% of the total examined. Twelve of the products positive for K. pneumoniae were various flavors of gelato, a frozen dessert prepared with pasteurized milk in small retail stores in Metropolitan Toronto, suggesting the importance of human handling in the introduction of K. pneumoniae. Thirteen different serotypes, including types previously associated with clinical infections, were represented in 25 isolates from 25 products. Type 13 occurred most frequently with five isolates from two products, cream cheese spread and cottage cheese, originating from two dairies.