Speciation and Biofilm Production of Coagulase Negative Staphylococcal Isolates from Clinically Significant Specimens and their Antibiogram
Background: Coagulase Negative Staphylococci (CONS) are increasingly recognized as significant nosocomial pathogens. Their ability of biofilm formation and multiple drug resistance are causing serious human infections. Aim and Objectives: To isolate, identify, speciate clinically significant CO...
Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
Krishna Institute of Medical Sciences University
2016-04-01
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Series: | Journal of Krishna Institute of Medical Sciences University |
Subjects: | |
Online Access: | http://www.jkimsu.com/jkimsu-vol5no2/JKIMSU,%20Vol.%205,%20No.%202,%20April-June%202016%20Page%2069-78.pdf |
Summary: | Background: Coagulase Negative Staphylococci
(CONS) are increasingly recognized as significant
nosocomial pathogens. Their ability of biofilm
formation and multiple drug resistance are causing
serious human infections. Aim and Objectives: To
isolate, identify, speciate clinically significant CONS
from various specimens, to study antibiotic resistance
pattern and biofilm production. Material and
Methods: Specimens were collected aseptically,
processed and identified upto the species level by a
simple scheme of tests urease, novobiocin resistance,
mannose and mannitol fermentation, ornithine
decarboxylase. Antibiotic sensitivity was done with
special reference to methicillin resistance. Biofilm
formation was detected by Congo Red Agar (CRA)
method and Tube Method (TM). Results: Study groupOf
100 isolates majority were pus (40), followed by
urine (28), blood (16), CSF (5), body fluids (4) and
catheter tips and implants (7). The most common
species isolated was S. epidermidis (40%) followed by
S. haemolyticus (26%), S. saprophyticus (15%), S.
schleiferi (13%), S. simulans (2%), S. cohnii (2%) and
S. warneri and S. capitis each 1%. Resistance to
penicillin was 91% followed by ampicillin (79%),
cotrimoxazole (67%). Methicillin resistance was 72%.
Biofilm producers were 69% by CRAmethod and 33%
by TM with majority species S. epidermidis (82.5%-
CRA and 55%-TM). Biofilm production was
significantly associated with MRCONS (p value
0.0036). Control group-Of 30 isolates were S.
epidermidis 66.6% followed by S. haemolyticus
(16.66%). Biofilm producers were 53.33% by CRA
method and 26.65% by TM with majority species S.
epidermidis (65%-CRA and 30%-TM).Methicillin
resistance was 26.6%. Conclusion: Clinical
significance of CONS is increasing day by day, so
there is a need for accurate identification to species
level and their antibiogram to avoid multidrug
resistance. Biofilm producing CONS species pose a
risk and CRA method for screening biofilm can be
used in all conventional microbiology laboratories.
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ISSN: | 2231-4261 2231-4261 |