title: Diagnostic and public health dilemma of lactose-fermenting Salmonella enterica serotype Typhimurium in cattle in the Northeastern United States.
abstract: The presence of lactose-fermenting Salmonella strains in clinical case materials presented to microbiology laboratories presents problems in detection and identification. Failure to detect these strains also presents a public health problem. The laboratory methods used in detecting lactose-fermenting Salmonella enterica serotype Typhimurium from six outbreaks of salmonellosis in veal calves are described. Each outbreak was caused by a multiply-resistant and lactose-fermenting strain of S. enterica serotype Typhimurium. The use of Levine eosin-methylene blue agar in combination with screening of suspect colonies for C8 esterase enzyme and inoculation of colonies into sulfide-indole-motility medium for hydrogen sulfide production was particularly effective for their detection. A hypothesis for the creation of lactose-fermenting salmonellae in the environment is presented. It is proposed that the environment and husbandry practices of veal-raising barns provide a unique niche in which lactose-fermenting salmonellae may arise.
authors.affiliation: Diagnostic Laboratory, Department of Population Medicine and Diagnostic Science, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA. plm2@cornell.edu
authors.forename: P L
authors.initials: PL
authors.lastname: McDonough
authors.forename: S J
authors.initials: SJ
authors.lastname: Shin
authors.forename: D H
authors.initials: DH
authors.lastname: Lein
mesh_terms: D000821:Animal Feed; D000822:Animal Husbandry / Q000592:standards; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D019072:Antibiotic Prophylaxis / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D004196:Disease Outbreaks / Q000662:veterinary*; D018432:Drug Resistance, Multiple; D005285:Fermentation; D007785:Lactose / Q000378:metabolism; D008460:Meat / Q000382:microbiology; D009511:New England / Q000453:epidemiology; D011634:Public Health; D012481:Salmonella Infections, Animal / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D019779:Salmonella enterica / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D012703:Serotyping
chemical_list: D000900:Anti-Bacterial Agents; D007785:Lactose