TITLE:
How Growth Ability of Multidrug-Resistant Escherichia coli Is Affected by Abiotic Stress Factors
AUTHORS:
Lucinda Janete Bessa, Vânia Filipa Dias, Ângelo Mendes, Paula Martins-Costa, Helena Ramos, Paulo Martins da Costa
KEYWORDS:
Escherichia coli, Multidrug Resistance, Nutrient Deprivation, pH, Salinity
JOURNAL NAME:
Open Journal of Preventive Medicine,
Vol.4 No.5,
April
29,
2014
ABSTRACT:
The ability of multidrug-resistant Escherichia coli to adapt and grow in a wide range of different
environmental conditions may be crucial to the global spread of antimicrobial
resistance. The aim of this study was to evaluate the survival ability of 54
multidrug-resistant E. coli strains,
isolated from three different biotopes (clinical setting, gull intestine, river
water) when subjected to variations in pH (from 3 to 11) and salinity (from
0.5% to 6% of NaCl) and to nutrient deprivation. The growth of each isolate as
well as of a reference strain was assessed during 168 h in every varying
condition. Slight variations in the growth ability under some abiotic stress
factors were recorded among the isolates from the different biotopes.
Multidrug-resistant isolates from gull feces were found to be the more tolerant
to environmental abiotic changes, while isolates from river water were the less
tolerant. In addition, it was notorious that the carriage of antimicrobial
resistance has a clear fitness cost in comparison with the susceptible (reference)
strain, highlighting the necessity of reducing the selective pressure exerted
by antibiotics. This study underlines the ecological hardness of
multidrug-resistant E. coli isolates
with a consequent ability to reach and colonize new host and environments.