Inappropriate use of antibiotics in humans and animals contributes to decreased antimicrobial susceptibility in bacteria of medical importance. Resistant bacteria being transferred from animals to humans are causing public health concern. In-person interviews were conducted with 20 dairy farmers in rural counties of South Carolina to determine farmers' knowledge and attitudes about prudent antibiotic use among livestock. Four focus groups (n = 22) were also conducted to ascertain farmers' specific information needs about proper antibiotic use. Survey results showed that participants (100%) typically determined a need for antibiotic treatment using symptom assessment and reported following some form of operating procedures regarding administration of antibiotics. Few farmers (32%) had actual written antibiotic protocols. Preferred information sources about antibiotics were veterinarians (100%) and other dairy farmers (50%). Most farmers (86%) were not concerned that overuse of antibiotics in animals could result in antibiotic resistance among farm workers. Qualitative analysis of focus groups revealed significant barriers to following proper antibiotic procedures including limited finances and lack of time. The need for bilingual educational resources for Hispanic/Latino dairy workers was expressed. Desired formats for educational materials were posters, flowcharts, videos, and seminars. Education of South Carolina dairy farmers by veterinarians and public health professionals on the appropriate use of antibiotics in dairy cattle is needed to ensure antibiotic effectiveness in both animals and humans.

OBJECTIVES: This study describes the epidemiology of raw milk-associated outbreaks reported to the Centers for Disease Control and Prevention from 1973 through 1992. METHODS: Surveillance data for each reported raw milk-associated outbreak were reviewed. A national survey was conducted to determine the legal status of intrastate raw milk sales for the period 1973 through 1995. RESULTS: Forty-six raw milk-associated outbreaks were reported during the study period; 40 outbreaks (87%) occurred in states where the intrastate sale of raw milk was legal. CONCLUSIONS: Consumption of raw milk remains a preventable cause of foodborne disease outbreaks.

Aims: Faecal samples from cattle in US feedlots were evaluated for the presence of Salmonella. When Salmonella isolates were recovered the antimicrobial resistance patterns were determined. Methods and Results: Faecal samples were collected from pen floors in 73 feedlots in 12 states during the period from October 1999 to September 2000. Pens of cattle selected for sampling were those that had been in the feedlot for the shortest period of time, the longest period of time and a randomly selected pen from the remaining pens. Faecal samples were cultured for Salmonella spp. and all Salmonella isolates were categorized by serotype. The susceptibilities of all isolates were determined using a panel of 17 antimicrobials. Overall, 6AE3% (654/10 417) of the samples cultured positive for Salmonella spp. and 22AE2% (94/422) of pens and 50AE7% (37/73) of feedlots had one or more positive samples. There was little difference in the proportion of positive samples from short-fed (6AE1%, 212/ 3482), random (6AE4%, 217/3400) and long-fed (6AE4%, 224/3485) pens of cattle. One of two pens of cattle that could not be attributed to a pen type had a single positive sample (2AE0%, 1/50). Samples collected during the period of April to June (6AE8%, 209/3054) and July to September (11AE4%, 286/2500) were more likely to be positive than those collected during October to December (4AE0%, 73/1838) and January to March (2AE8%, 86/3025). The most common serotypes of Salmonella were dissimilar from those that are typically seen in human illness and cattle illness. The majority of isolates (62AE8%, 441/702) were sensitive to all of the antimicrobials tested. Resistance was most frequently observed to tetracycline (35AE9%, 252/702) followed by streptomycin (11AE1%, 78/702), ampicillin (10AE4%, 73/702) and chloramphenicol (10AE4%, 73/702). Multiple resistance (resistance to ‡2 antimicrobials) was observed for 11AE7% (82/702) of the isolates. Conclusions: Salmonella was isolated at low frequency from faeces of feedlot cattle and the serotypes were not those commonly associated with human illness. In addition most of the Salmonella isolates were sensitive to all the antimicrobials tested. Significance and Impact of the Study: This study contributes to understanding the ecology of Salmonella in cattle feedlots and the prevalence of resistance among potential food-borne pathogens.

Our study found a high prevalence of Salmonella in retail meats and persons with enteric infection; many of these isolates were resistant to clinically important antimicrobials. A random selection of isolates from people and retail meat showed genetic relatedness, which suggests that, in Yucatan, considerable transfer of Salmonella occurs through the food chain.

Salmonella serotypes are important foodborne pathogens of humans that can be acquired through consumption of contaminated meat and dairy products. Salmonella infection also can be a significant animal health issue. As part of a national study of U.S. dairy operations conducted between March and September 2002, fecal samples were collected from representative cows in 97 dairy herds in 21 states and were cultured to determine the prevalence of Salmonella shedding. Salmonella was recovered from the feces of at least one cow in 30.9% of the herds. Overall, 7.3% of fecal samples were culture positive for Salmonella. The three most frequently recovered serotypes were Salmonella Meleagridis (24.1%), Salmonella Montevideo (11.9%), and Salmonella Typhimurium (9.9%). The susceptibilities of Salmonella isolates recovered were determined using a panel of 16 antimicrobial drugs. Salmonella isolates recovered from dairy cows had relatively little resistance to these antimicrobial agents; 83.0% of the isolates were susceptible to all antimicrobials tested. This study provides updated information on the prevalence and susceptibility patterns of Salmonella in dairy herds and on cow and herd characteristics. These data contribute to our understanding of the ecology of Salmonella in the dairy farm environment.