PREVALENCE OF METHICILLIN RESISTANT STAPHYLOCOCCUS aureus WITH PARTICULAR MENTION OF LOW LEVEL VANCOMYCIN RESISTANCE IN BURNS WOUND INFECTION PATIENTS

Abstract

Abstract :
Burns wound infection accounts for nearly
75 percentage of deaths following burns.
Staphylococcus aureus has been reported
as a major cause of community and hospital
acquired infections. Wide spread occurrence
of Methicillin Resistant Staphylococcus
aureus (MRSA) and the use of vancomycin
to treat infections has resulted in
low level resistance even to vancomycin.
The objective of the study was to detect
MRSA strains in the wound swabs of the
burns patients.These MRSA strains were
observed for low level vancomycin resistance.
A total of 214 wound swabs was collected
from the burns wound infection patients
and processed according to standard
laboratory techniques.Antimicrobial
susceptibility testing was done by Kirby-
Bauer disc diffusion method using the antibiotic
discs namely ampicillin (10 micro
g m ) , e r y t h r o m y c i n ( 1 5 m i c r o
gm),gentamycin(10micro gm),amikacin
(30mi c ro gm),o f l o x a c i n ( 5 m i c r o
gm),oxacillin(1micro gm), cefoxitin,
(30micro gm ), vancomycin
(30 micro gm), linezolid (30 micro gm)..
The percentage of staphylococcus aureus
isolated in wound swabs was 99 (46 percent).
MRSA detection was done by Oxacillin
disc diffusion method and Cefoxitin
disc diffusion method .Percentage of
MRSA detected by both methods was 48
(48.5 percent).VISA was detected by Disc
diffusion method,Vancomycin screen agar
method and Agar dilution method.In Agar
dilution method two strains had MIC 8 micro
gm per ml for vancomycin.None of the
strains were VRSA with MIC more than 16
micro gm per ml.. In Vancomycin screen
agar the same two strains showed visible
growth.But in Disc diffusion method all the
strains were sensitive to vancomycin.
Thus disc diffusion method may not be a
reliable method for VISA detection. Vancomycin
screen agar results coincides
with agar dilution method. Thus vancomycin
screen agar may be used as a preliminary
screening test for VISA In the present
study both the VISA strains showed
100 percent susceptibility to linezolid.In
conclusion,