|Baumgard, L - UNIVERSITY OF ARIZONA|
|Griswold, K - SOUTHERN ILLINOIS UNIV|
Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 14, 2005
Publication Date: September 2, 2005
Citation: Callaway, T.R., Keen, J.E., Edrington, T.S., Anderson, R.C., Genovese, K.J., Poole, T.L., Harvey, R.B., Nisbet, D.J., Baumgard, L.H., Griswold, K.E. 2005. Fecal prevalence and diversity of Salmonella spp. in lactating dairy cattle in four states. Journal of Dairy Science. 88:3603-3608. Interpretive Summary: Salmonella is a food-borne pathogenic bacteria that causes an estimated 1.3 million human illnesses in the United States each year. Dairy cows can be reservoirs of Salmonella spp. The present study was designed to examine the different types (serotypes) of Salmonella on dairies. Approximately 10% of samples taken from 13,200 dairy cows were positive for Salmonella, and 56% of the herds had at least one positive sample. Seventeen (n = 17) different types of Salmonella were isolated. There were 2 or more different types of Salmonella present on 78% of the Salmonella-positive farms. From our data, it appears that Salmonella is a very diverse bacteria that is widespread across U.S. dairies.
Technical Abstract: Salmonella is one of the most serious food-borne pathogenic bacteria in the United States, causing an estimated 1.3 million human illnesses each year. Dairy cows can be reservoirs of food-borne pathogenic bacteria, including Salmonella spp, and it is estimated that up to 31% of dairy herds from across the U. S. are colonized by Salmonella. The present study was designed to examine the prevalence of Salmonella spp. on dairies and to examine the serotypic diversity of Salmonella isolates across the U.S. Fecal samples (n = 60/dairy) were collected from four (n = 4) dairies in each state (n = 4) for a total of n = 960 fecal samples. In the present study, a total of 93 out of 960 samples (9.96%) collected from a pooled population of 13,200 dairy cattle were culture positive for Salmonella enterica. At least one Salmonella fecal-shedding cow was found in 9 of the 16 herds (56%) and the within-herd prevalence varied in our study from 0% in seven herds, to a maximum of 37% in two herds, with a prevalence mean among Salmonella-positive herds of 17%. Seventeen (n = 17) different serotypes were isolated, representing 7 different Salmonella serogroups. There were 2 or more different serogroups and serotypes present on 7 of the 9 Salmonella-positive farms. Serotypes Montevideo and E1 Muenster were the most frequent and widespread. From our data, it appears that subclinical colonization with Salmonella enterica is quite widespread and is represented by diverse serotypes throughout the U.S. dairy industry.