Genetic lineages of Salmonella enterica serovar Kentucky spreading in pet reptiles
Abstract
The purpose of the study was to define genetic diversity of reptilian Salmonella enterica
serovar (S.) Kentucky isolates and their epidemiological relations to the ones from poultry,
food, and environmental origin in Poland. Between 2010 and 2012 twenty-four S.
Kentucky isolates derived from snakes (N = 8), geckos (N = 7), chameleons (N = 4), agamas
(N = 1), lizard (N = 1), and environmental swabs taken from reptile exhibition (N = 3) were
identified. They were characterized with antimicrobial minimal inhibitory concentration
testing, XbaI–PFGE and MLST typing. The profiles compared to S. Kentucky available in
BioNumerics local laboratory database (N = 40) showed 67.3% of relatedness among reptile
isolates. Three genetic lineages were defined. The first lineage gathered 20 reptile isolates
with 83.4% of similarity and wild-type MICs for all antimicrobials tested but streptomycin
in single case. The remaining three reptilian and one post-exhibition environment S.
Kentucky isolates were clustered (87.2%) with isolates originating from poultry, mainly
turkey, food, and environment and presented variable non-wild type MICs to numerous
antimicrobials. The third S. Kentucky lineage was composed of two isolates from feed
(96.3%). The results suggest diverse sources and independent routes of infection. Most of
the isolates belonged to reptile-associated clones spread both horizontally and vertically.
Simultaneously, PFGE profiles and MLST type indistinguishable from the ones observed in
poultry point out carnivore reptiles as possible vector of infection with multidrug and
high-level ciprofloxacin resistant (MIC 8 mg/L) S. Kentucky. Public awareness and
education are required to prevent potential reptile-associated S. Kentucky infections in
humans.