Establish a Caenorhabiditis elegans model of cuticle infection due to Aeromonas dhakensis a common and virulent Aeromonas species in southern Taiwan

Abstract

BACKGROUND: Most human Aeromonas infections were reported to be associated with three species i e Aeromonas hydrophila Aeromonas veronii and Aeromonas caviae Several studies report that isolates originally identified as A hydrophila based on phenotypic methods can be recognized as A dhakensis using molecular typing Additionally identification of Aeromonas species using the matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is rarely reported In human Aeromonas infection the clinical features and microbiological features of A dhakensis and other Aeromonas species are rarely being compared In addition the host-microbe interaction in Aeromonas infection remains unclear In the present research our hypothesis is A dhakensis is a virulent species which can cause severe infections in hosts In the first part of our study we assessed the performance of MALDI-TOF MS system (Microflex LT; Bruker Daltonik GmbH Bremen Germany) to identify the clinical Aeromonas species Secondly we compared the clinical and biological features of Aeromonas clinical isolates from human wounds and blood In the final part we established A dhakensis cuticle infection model in Caenorhabditis elegans and used it to study the innate p38 mitogen-activated protein kinase pathway against Aeromonas infections RESULTS: The accuracy identification rates by MALDI-TOF for A dhakensis A hydrophila A veronii and A caviae were 96 7% 90 0% 96 7% and 100 0% respectively Of note we highlighted its potential for antimicrobial resistance among A dhakensis isolates showing the resistance rates of ertapenem and gentamicin to be 12 1% and 6 9% respectively A dhakensis isolates formed more solid surface-associated biofilms than A hydrophila isolates (P=0 03) In liquid toxicity assay the average survival rates of C elegans infected with A dhakensis isolates on day 1-3 were significantly lower than those of A hydrophila isolates (all P values

Date of Award	2015 Aug 6
Original language	English
Supervisor	Chang-Shi Chen (Supervisor)