Author/Authors :
Ebrahimi Azizollah نويسنده Department of Pathobiology, School of Veterinary Science, Shahrekord University, Shahrekord, IR Iran , Lotfalian Sharareh نويسنده Department of Pathobiology, School of Veterinary Science, Shahrekord University, Shahrekord, IR Iran , mahzounieh mohamadreza نويسنده Shahrekord University,Iran محزونيه محمد رضا , Arvaneh Zohreh نويسنده Department of Pathobiology,Veterinary College, Shahrekord
University, IR Iran
Abstract :
Background Biocides (disinfectants) are crucial for controlling
various infections and are widely used in environments for the control
of microorganisms. Exposure of bacteria to biocides can select for
mutants with decreased biocide susceptibility that often display a
decrease in susceptibility to antibiotics. Objectives The present work
was done during 14 months from February 2015, at the microbiology
laboratory of the Veterinary college of Shahrekord university with the
aim of investigating the impact of benzalkonium chloride exposure on
antibiotic resistance in some common nosocomial pathogens. Methods
Standard strains of Pseudomonas aeruginosa,
Acinetobacter baumannii, Escherichia
coli and Staphylococcus aureus were used,
and in parallel to each standard strain four hospital isolates collected
from Shahrekord and Esfahan hospitals were examined. Tube double serial
dilution method was used for determination of minimum inhibitory
concentration (MIC) of antibiotics and Benzalkonium Chloride (BKC).
Spontaneous mutants were developed by exposure of examined species to
BKC, and their mean MICs to examined drugs were evaluated. Results The
mean MICs of the BKC and antibiotics used in this study were not similar
between the parent and mutant strains of the examined isolates. In
E. coli, A. baumannii and
S. aureus isolates, differences between the mean MICs
of BZK and ciprofloxacin had a similar pattern and were statistically
significant (P < 0.05). In isolates of P.
aeruginosa, differences between parent and mutant isolates for
all of the tested drugs were significant. Conclusions Vast use of BKC in
various environments and their accumulation represents a potential risk
for selective pressure towards selection of bacteria with decreased
antibiotic susceptibility.