RT Journal Article
SR Electronic
T1 Whole genome sequencing identifies independent outbreaks of Shigellosis in 2010 and 2011 in La Pampa Province, Argentina
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 049940
DO 10.1101/049940
A1 Isabel Chinen
A1 Marcelo Galas
A1 Ezequiel Tuduri
A1 Maria Rosa Viñas
A1 Carolina Carbonari
A1 Anabella Della Gaspera
A1 Daniela Nápoli
A1 David M Aanensen
A1 Silvia Argimón
A1 Nicholas R Thomson
A1 Darren Hughes
A1 Stephen Baker
A1 Caterina Guzmán-Verri
A1 Matthew TG Holden
A1 Alejandra M Abdala
A1 Lucia P Alvarez
A1 Beatriz Alvez
A1 Rosana Barros
A1 Shirley Budall
A1 Constanza Campano
A1 Luciana S Chamosa
A1 Paul Cheddie
A1 Daniel Cisterna
A1 Denise De Belder
A1 Milena Dropa
A1 David Durand
A1 Alan Elena
A1 Gustavo Fontecha
A1 Claudia Huber
A1 Ana Paula Lemos
A1 Luciano Melli
A1 Roxana Elizabeth Paul
A1 Lesly Suarez
A1 Julian Torres Flores
A1 Josefina Campos
YR 2016
UL http://biorxiv.org/content/early/2016/04/28/049940.abstract
AB Shigella sonnei is an emergent cause of diarrheal disease in middle-income countries. The organism causes endemic disease and is also associated with sporadic outbreaks in susceptible populations. In 2010 and 2011 there were two suspected outbreaks of diarrheal disease caused by S. sonnei in La Pampa province in central Argentina. Aiming to confirm these as outbreaks and provide insight into the relationship of the strains causing these infections we combined antimicrobial susceptibility testing and pulsed field gel electrophoresis (PFGE) with whole genome sequencing (WGS). Antimicrobial susceptibility testing suggested the two events were unrelated; organisms isolated in 2010 exhibited resistance to trimethoprim sulphate whereas the 2011 S. sonnei were non-susceptible against ampicillin, trimethoprim sulphate and cefpodoxime. PFGE profiling confirmed the likelihood of two independent outbreaks, separating the isolates into two main XbaI restriction profiles. We additionally performed WGS on 17 isolates associated with these outbreaks. The resulting phylogeny confirmed the PFGE structure and separated the organisms into two comparatively distantly related clones. Antimicrobial resistant genes were common, and the presence of an OXA-1 was likely associated with resistance to cefpodoxime in the second outbreak. We additionally identified novel horizontally transferred genetic material that may impinge on the pathogenic phenotype of the infecting strains. Our study shows that even with a lack of supporting routine data WGS is an indispensible method for the tracking and surveillance of bacterial pathogens during outbreaks and is becoming a vital tool for the monitoring of antimicrobial resistant strains of S. sonnei.