title: Investigation into the seasonal salmonellosis in lactating dairy cattle.
abstract: Sporadic salmonellosis has been reported in mature lactating dairy cattle in the southwestern United States and is an intriguing problem in that Salmonella can be cultured from faecal samples of these cattle throughout the year. However, it is pathogenic only during late summer/early autumn and in certain years. We sampled apparently healthy (n=10) and diarrhoeic (n=10) cattle during an outbreak on a 2000 head dairy in 2003. The following year, monthly faecal (from the same 30 head), total mixed ration, water, and pen soil samples were collected for Salmonella culture. No serogroup, serotype, genetic, or antimicrobial susceptibility differences were observed in comparison of isolates from healthy and sick cattle. During year 2 of the study, Salmonella was routinely cultured (although highly variable from month to month) from the cattle and the environment, although no outbreak of salmonellosis was observed.
authors.affiliation: USDA-ARS, Food and Feed Safety Research Unit, College Station, TX 77845, USA. edrington@ffsru.tamu.edu
authors.forename: T S
authors.initials: TS
authors.lastname: Edrington
authors.forename: T T
authors.initials: TT
authors.lastname: Ross
authors.forename: T R
authors.initials: TR
authors.lastname: Callaway
authors.forename: C H
authors.initials: CH
authors.lastname: Martinez
authors.forename: M E
authors.initials: ME
authors.lastname: Hume
authors.forename: K J
authors.initials: KJ
authors.lastname: Genovese
authors.forename: T L
authors.initials: TL
authors.lastname: Poole
authors.forename: R C
authors.initials: RC
authors.lastname: Anderson
authors.forename: D J
authors.initials: DJ
authors.lastname: Nisbet
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000209:etiology; D003612:Dairying; D004196:Disease Outbreaks / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D005260:Female; D007774:Lactation; D012475:Salmonella / Q000302:isolation & purification; D012481:Salmonella Infections, Animal / Q000453:epidemiology* / Q000209:etiology; D012621:Seasons; D015206:Southwestern United States / Q000453:epidemiology