Sensibilidad a cobre y cinc y corresistencias en bacterias de alimentos vegetales no procesados
- CIDRE FERNÁNDEZ, ISMAEL
- Rubén Pérez Pulido Director
- Antonio Gálvez del Postigo Ruiz Co-director
Defence university: Universidad de Jaén
Fecha de defensa: 24 July 2017
- Manuel Martínez Bueno Chair
- Elena Ortega Morente Secretary
- Samir Ananou Committee member
Type: Thesis
Abstract
Copper and zinc resistance was studied in 506 isolates (aerobic mesophiles) from 12 different fresh produce products. Over 50% of isolates had minimum inhibitory concentrations (MICs) for copper sulfate above 16 mM, and over 40% had MICs > 4 mM for zinc chloride. 51 isolates with high MICs for both copper and zinc were identified by 16S rDNA sequencing. Forty of them were gram-negative bacteria belonging to genera Pseudomonas (28), Enterobacter (7), Serratia (4) and Leclercia (1). A high incidence of genes from the pco multicopper oxidase cluster and the sil cluster involved in copper and silver resistance, as well as the chromate resistance gene chrB. Remarkably, a high percentage of the studied isolates carried both pco and sil genetic determinants. Results suggest that copper and zinc resistance as well as metal resistance genes are widespread in bacteria from fresh produce.