TY - JOUR
T1 - Population dynamics of salmonella enterica within beef cattle cohorts followed from single-dose metaphylactic antibiotic treatment until slaughter
AU - Levent, Gizem
AU - Schlochtermeier, Ashlynn
AU - Ives, Samuel E.
AU - Norman, Keri N.
AU - Lawhon, Sara D.
AU - Loneragan, Guy H.
AU - Anderson, Robin C.
AU - Vinasco, Javier
AU - Scott, H. Morgan
N1 - Funding Information:
We acknowledge the H. M. Scott laboratory graduate and undergraduate students and Roberta Pugh for assisting during intensive sample processing. We acknowledge Jing Wu for her assistance using the MALDI-TOF device in the Clinical Microbiology Laboratory of the College of Veterinary Medicine and Biomedical Sciences at Texas A&M University and Roger Harvey at the USDA/ARS, College Station, TX, laboratory for allowing access to the Sensititre reader. Special thanks go to Tom Edrington (Diamond V, Cedar Rapids, IA) for providing advice on lymph node and hide sample processing. This study was funded by the National Cattlemen's Beef Association, a contractor to the Beef Checkoff (no. 22615).
Publisher Copyright:
© 2019 American Society for Microbiology.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Antibiotic use in cattle can select for multidrug-resistant Salmonella enterica, which is considered a serious threat by the U.S. Centers for Disease Control and Prevention. A randomized controlled longitudinal field trial was designed to determine the long-term effects of a single dose of ceftiofur or tulathromycin on Salmonella population characteristics in cattle feces and peripheral lymph nodes and on hides. A total of 134 beef cattle from two sources were divided among 12 pens, with cattle in each of the 3-pen blocks receiving a single dose of either ceftiofur or tulathromycin or neither (control) on day 0. Fecal samples were collected before treatment (day 0) and repeatedly following treatment until slaughter (day 99+). Hide and lymph node samples were collected at slaughter age. Salmonella prevalence, phenotypic antimicrobial resistance, serotype, and phylogenetic relationships were examined. Multilevel mixed logistic regression models indicated no significant effects (P ≥ 0.218) of metaphylactic antibiotics on the prevalence of Salmonella across sample types. However, there was a significant time effect observed, with prevalence increasing from spring through the midsummer months (P < 0.0001) in feces. The majority of Salmonella isolates were pansusceptible to a panel of 14 antibiotics both before and after treatment. Highly prevalent Salmonella serotypes were Salmonella enterica serovar Montevideo, Salmonella enterica serovar Anatum, Salmonella enterica serovar Cerro, and Salmonella enterica serovar Lubbock across all sample types. Strong pen and cattle source serotype clustering effects were observed among Salmonella isolates originating from fecal, lymph node, and hide samples; however, the potential role of Salmonella isolates from the pen environment prior to animal placement was not assessed in this study.
AB - Antibiotic use in cattle can select for multidrug-resistant Salmonella enterica, which is considered a serious threat by the U.S. Centers for Disease Control and Prevention. A randomized controlled longitudinal field trial was designed to determine the long-term effects of a single dose of ceftiofur or tulathromycin on Salmonella population characteristics in cattle feces and peripheral lymph nodes and on hides. A total of 134 beef cattle from two sources were divided among 12 pens, with cattle in each of the 3-pen blocks receiving a single dose of either ceftiofur or tulathromycin or neither (control) on day 0. Fecal samples were collected before treatment (day 0) and repeatedly following treatment until slaughter (day 99+). Hide and lymph node samples were collected at slaughter age. Salmonella prevalence, phenotypic antimicrobial resistance, serotype, and phylogenetic relationships were examined. Multilevel mixed logistic regression models indicated no significant effects (P ≥ 0.218) of metaphylactic antibiotics on the prevalence of Salmonella across sample types. However, there was a significant time effect observed, with prevalence increasing from spring through the midsummer months (P < 0.0001) in feces. The majority of Salmonella isolates were pansusceptible to a panel of 14 antibiotics both before and after treatment. Highly prevalent Salmonella serotypes were Salmonella enterica serovar Montevideo, Salmonella enterica serovar Anatum, Salmonella enterica serovar Cerro, and Salmonella enterica serovar Lubbock across all sample types. Strong pen and cattle source serotype clustering effects were observed among Salmonella isolates originating from fecal, lymph node, and hide samples; however, the potential role of Salmonella isolates from the pen environment prior to animal placement was not assessed in this study.
KW - Antibiotic resistance
KW - Antimicrobial resistance
KW - Beef cattle
KW - Feces
KW - Feedlot cattle
KW - Hide
KW - Lymph node
KW - Metaphylaxis
KW - Salmonella
UR - http://www.scopus.com/inward/record.url?scp=85075093115&partnerID=8YFLogxK
U2 - 10.1128/AEM.01386-19
DO - 10.1128/AEM.01386-19
M3 - Article
C2 - 31519659
AN - SCOPUS:85075093115
VL - 85
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
SN - 0099-2240
IS - 23
M1 - e01386-19
ER -