Isolation, biochemical characterization and antibiotic susceptibility of Yersinia enterocolitica isolates from milk

Citation
R. Kushal et Sk. Anand, Isolation, biochemical characterization and antibiotic susceptibility of Yersinia enterocolitica isolates from milk, J FD SCI M, 38(2), 2001, pp. 129-134
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Food Science/Nutrition
Journal title
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
ISSN journal
0022-1155 → ACNP
Volume
38
Issue
2
Year of publication
2001
Pages
129 - 134
Database
ISI
SICI code
0022-1155(200103/04)38:2<129:IBCAAS>2.0.ZU;2-E
Abstract
Yersinia enterocolitica isolates of milk origin were biochemically characte rized using presumptive and primary identification schemes. Additional bioc hemical tests were carried out to confirm the typical isolates. On the basi s of colony morphology on Cefsulodin-Irgasan-Novobiocin (CIN) agar, 65 samp les out of 110 were found to have typical Yersinia colonies. The alkati (KO H+ NaCl) treatment increased the selectivity of the isolation procedure. On the basis of H2S negative, urease positive and esculin negative tests, 58 isolates were identified as presumptive Yersinia. These were screened for a ntibiotic susceptibility by disc assay. The results revealed that gentamyci n (10 mug) and streptomycin (10 mug) were the most effective. On the other hand, penicillin G (10 units) was most ineffective, as about 54 culture iso lates were completely resistant to this antibiotic. Further tests for oxida se negative, catalase positive and lipase negative or delayed positive resu lted in the primary identification of 47 isolates on Yersinia enterocolitic a. The additional biochemical tests for confirmation of the typical strains were negative decarboxylase test for lysine and arginine, inability to dea minate phenylalanine, motility at 25 degreesC, a negative response to citra te utilization and VP test and negative or delayed positive indole producti on. A total of 36 isolates were identified as confirmed Yersinia enterocoli tica. A number of sugar fermentation tests were also conducted to substanti ate the results.