|KIM, SEON-WOO - University Of Maryland|
|HAENDIGES, JULIE - Maryland Department Of Health And Mental Hygiene|
|KELLER, ERIC - Maryland Department Of Health And Mental Hygiene|
|TORPEY, DAVID - Maryland Department Of Health And Mental Hygiene|
|KIM, ALEXANDER - Maryland Department Of Health And Mental Hygiene|
|CROCKER, KIA - Maryland Department Of Health And Mental Hygiene|
|MYERS, ROBERT - Maryland Department Of Health And Mental Hygiene|
|Van Kessel, Jo Ann|
Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2019
Publication Date: 3/19/2019
Citation: Haley, B.J., Kim, S., Haendiges, J., Keller, E., Torpey, D., Kim, A., Crocker, K., Myers, R.A., Van Kessel, J.S. 2019. Salmonella enterica serovar Kentucky recovered from human clinical cases in Maryland, USA (2011 to 2015). Journal of Clinical Microbiology. 66:382-392. https://doi.org/10.1111/zph.12571.
Interpretive Summary: Salmonella Kentucky is frequently isolated from poultry and dairy cows in the United States and from clinical cases of salmonellosis in people who have traveled to Africa, South Asia, Eastern Europe, and the Middle East. However, a description of these salmonellosis cases and the Salmonella Kentucky strains that cause these infections in the United States is lacking. Further, it is not known what proportion of these infections is due to consumption of food products in the United States or abroad. To address these questions we sequenced the genomes of all S. Kentucky isolates recovered from human clinical cases in Maryland between 2011 and 2015 and compared them to the genomes of over 200 previously sequenced S. Kentucky isolates collected from human clinical cases, food, and the environment in the United States and abroad. Results of this analysis indicated that the majority of infections caused by S. Kentucky in the State of Maryland are associated with international travel or are closely related to strains that are isolated outside of the United States. In this analysis these strains that were acquired abroad were all found to be resistant to multiple antibiotics including those used to treat Salmonella infections in humans. Several of the S. Kentucky strains isolated from human clinical cases in Maryland were closely related to poultry-associated isolates recovered in the United States while others were closely related to both dairy cow and poultry-associated isolates. These strains were susceptible to all tested antibiotics. This work furthers our understanding of the salmonellae that are found in common food producing animals in the United States and those that are imported from abroad.
Technical Abstract: Salmonella enterica subsp. enterica serovar Kentucky represents multiple sequence types (ST) of genetically diverged S. enterica with a similar O- and H-antigenic constellation acquired through lateral gene transfer. Currently the genomic features of human clinical S. Kentucky strains isolated in the United States remains poorly described, although these features have been described in-depth for poultry and dairy cow-associated strains. To further understand characteristics of human clinical S. Kentucky the genomes of 12 isolates recovered from clinical cases in the State of Maryland (USA) between 2011 and 2015 were sequenced and compared to a database of 368 previously sequenced S. Kentucky isolates representing 12 sequence types collected from multiple sources on several continents. Clinical isolates from Maryland represented ST152 (n=2), ST314 (n=1), and ST198 (n=9). All isolates that were not recovered from individuals with international travel history (ST152 and 314, and two ST198) were susceptible to a panel of nine antibiotics, while seven isolates recovered from individuals with international travel histories (ST198) were resistant to at least three antibiotics. All isolates excluding the ST314 isolate and one ST198 isolate encoded antibiotic resistance genes, with seven ST198 genomes encoding Salmonella Genomic Island 1 (SGI 1) and substitutions known to confer nalidixic acid and ciprofloxacin resistance. Case report data on food consumption and travel were, for the most part, consistent with the phylogeny of S. Kentucky.