Salmonella in Dairy Operations in the United States: Prevalence and Antimicrobial Drug Susceptibility

Abstract

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.

Prevalence and antimicrobial susceptibility of Salmonella species from lactating cows in dairy farm of Bahir Dar Town, Ethiopia

“…11.5 and 7.1% conducted in Kombolcha and Debre Zeit, Ethiopia (Minte et al, 2011;Daniel et al, 2003), respectively. This study is in agreement with the report of Blau et al (2004) who indicated that prevalence of Salmonella spp. was recorded in 7.3% in Dairy Operations in the United States (USA).…”

“…This is also comparable with the result conducted in USA (Blau et al, 2004). In line with this, the result of these antimicrobial agents, like ciprofloxacin and gentamycin, is covenant with the study done in Asella town, Ethiopia (Takele et al, 2016) and norfloxacin, in Harrer (Ayalu et al, 2011) and in Sudan (Fadlalla et al, 2012).…”

Isolation, identification and antimicrobial susceptibility profiles of <i>Salmonella</i> isolates from dairy farms in and around Modjo town, Ethiopia

“…Hence lactating cows could be potential sources of Salmonella infection for individuals working in dairy farms and for the community at large. Fecal prevalence of Salmonella among lactating dairy cattle in the current study was 7.7% (7/91) which is interestingly similar with the fecal Salmonella isolation rate of 7.7% in lactating cows and in contact humans in dairy farms of Addis Ababa (Zelalem Addis et al, 2011) and 7.3% in dairy cows in USA (Blau et al, 2005). However, it is lower than the fecal Salmonella isolation rate of 9.7% in United States (Callaway et al, 2005).…”

“…This result strongly disagrees with the current study in which 96.4% and 39% of the isolates were resistant to tetracycline and ampicillin, respectively. Resistance rates to ampicillin and tetracycline is very high when compared to results documented in America (Blau et al, 2005) reported as 4.4 % and 12.2 % resistance levels, respectively.…”

Salmonella entericaSerotype Cerro Among Dairy Cattle in New York: An Emerging Pathogen?

“…This is in agreement with the apparent correlation between antimicrobial resistance and the presence of clinical disease in dairy cattle. Studies of fecal Salmonella shedding among healthy cattle across the United States have shown antimicrobial resistance to be uncommon (Wells et al, 2001;Blau et al, 2005;Ray et al, 2007), but multidrug resistance was found to be highly prevalent among isolates from cattle with clinical signs of salmonellosis in the northeastern United States (Cummings et al, 2009). A similar phenomenon has also been observed in people, as infections with resistant Salmonella strains tend to be more severe and lead to higher rates of hospitalization than those caused by susceptible strains (Helms et al, 2002(Helms et al, , 2004Varma et al, 2005aVarma et al, , 2005b.…”