Title |
Candida krusei isolated from fruit juices ultrafiltration membranes promotes colonization of Escherichia coli O157:H7 and Salmonella enterica on stainless steel surfaces |
Author |
María Clara Tarifa1, Jorge Enrique Lozano1, and Lorena Inés Brugnoni2* |
Address |
1Pilot Plant of Chemical Engineering (UNS-CONICET) Camino La Carrindanga Km 7 (8000) Bahía Blanca, Argentina, 2Institute of Biological and Biomedical Sciences of the South (UNS-CONICET) San Juan 670 (8000) Bahía Blanca, Argentina |
Bibliography |
Journal of Microbiology, 55(2),96-103, 2017,
|
DOI |
10.1007/s12275-017-6300-3
|
Key Words |
Candida krusei, Escherichia coli O157:H7, Salmonella
enterica, apple juice, stainless steel |
Abstract |
To clarify the interactions between a common food spoilage
yeast and two pathogenic bacteria involved in outbreaks associated
with fruit juices, the present paper studies the effect
of the interplay of Candida krusei, collected from UF membranes,
with Escherichia coli O157:H7 and Salmonella enterica
in the overall process of adhesion and colonization of
abiotic surfaces. Two different cases were tested: a) co-adhesion
by pathogenic bacteria and yeasts, and b) incorporation
of bacteria to pre-adhered C. krusei cells. Cultures were made
on stainless steel at 25°C using apple juice as culture medium.
After 24 h of co-adhesion with C. krusei, both E. coli O157:H7
and S. enterica increased their counts 1.05 and 1.11 log CFU
cm2, respectively. Similar increases were obtained when incorporating
bacteria to pre-adhered cells of Candida. Nevertheless
C. krusei counts decreased in both experimental conditions,
in a) 0.40 log CFU cm2 and 0.55 log CFU cm2 when
exposed to E. coli O157:H7 and S. enterica and in b) 0.18 and
0.68 log CFU cm2, respectively. This suggests that C. krusei,
E. coli O157:H7, and S. enterica have a complex relationship
involving physical and chemical interactions on food contact
surfaces. This study supports the possibility that pathogen
interactions with members of spoilage microbiota, such
as C. krusei, might play an important role for the survival and
dissemination of E. coli O157:H7 and Salmonella enterica in
food-processing environments. Based on the data obtained
from the present study, much more attention should be given
to prevent the contamination of these pathogens in acidic
drinks. |