|
OJHAS Vol. 9, Issue 4:
(Oct-Dec, 2010) |
|
|
| Increasing
Trends of Methicillin Resistant Coagulase
Negative Staphylococcus in Neonatal Septicaemia - A Study in a Tertiary Care Hospital,
Mysore, South India |
|
Deepa S, Assistant
Professor,
Amruta Kumari B, Associate
Professor,
Venkatesha D, Professor & Head,
Dept. of Microbiology, Mysore Medical College & Research Institute,
Mysore. |
|
|
| |
|
|
|
|
|
|
Address For Correspondence |
Assistant Professor,
Department of Microbiology,
MMC&RI,
Irwin road,
Mysore, Karnataka.
E-mail:
drdeepa_intel@yahoo.co.in |
|
|
|
|
|
Deepa S, Kumari AB, Venkatesha D. Increasing
Trends of Methicillin Resistant Coagulase
Negative Staphylococcus in Neonatal Septicaemia - A Study in a Tertiary Care Hospital,
Mysore, South India. Online J Health Allied Scs.
2010;9(4):11 |
|
|
|
|
Submitted: Dec 20,
2010; Accepted: Dec 31, 2010; Published: Jan 20, 2011 |
|
|
|
|
|
|
|
| |
|
| Abstract: |
|
Introduction: Neonatal
septicaemia is one among the leading causes of neonatal mortality in
India. For the last 20 years CoNS has been identified as a major cause
of neonatal septicaemia in NICU. Different studies show 70-75% of CoNS
as resistant to methicillin. Material and methods:
Blood samples from neonatal septicaemia cases during Dec 2007 to Dec
2010 were processed & isolates were identified. CoNS were biotyped
& methicillin resistance was detected using cefoxitin 30 µg disk. Results: Of 2256 blood
samples from neonatal septicaemia cases, 587(36.98%) were CoNS. Staphylococcus
epidermidis 234(39.86%) was the commonest isolate. Methicillin resistance
was noted in 286 (48.72%). MRCoNS prevalence during 2008, 2009 &
2010 were 41.57%, 47% and 57.36% respectively. Conclusion: Our study
showed increased trends of MR-CoNS in neonatal septicaemia leading to
increased usage of vancomycin & other glycopeptides, resulting in
emergence of multidrug resistant strains, thus narrowing the treatment
options in neonates.
Key Words: Neonatal septicaemia; Coagulase
Negative Staphylococcus; Methicillin resistance
|
|
Neonatal septicaemia is one
among the leading causes of neonatal mortality in India. The spectrum
of organisms causing neonatal septicaemia is quiet different in developed
countries in comparison with developing countries like India.1
Also there exists regional variation in the spectrum of organisms causing
sepsis.2 For the last 20 years Coagulase negative Staphylococci
(CoNS) has been identified as a major cause of neonatal septicaemia
in Neonatal Intensive Care Unit (NICU). The increasing recognition of
pathogen potential CoNS and emergence of drug resistance among them
demonstrates the need to identify and determine the prevalence of CoNS.3
Data from the world wide SENTRY study showed that, independent of geographic
origin, 70-75% of CoNS are nowadays resistant to methicillin.4
Similarly the rate of multidrug resistant CoNS is in increased trend.
On this account vancomycin has been widely used and it is the major
cause for the emergence of glycopeptide resistant isolates.
On this basis in the present
study an attempt has been made to evaluate the prevalence of Methicillin
resistant Coagulase negative Staphylococci (MR-CoNS) in neonatal septicaemia
in our hospital.
This study was carried
out in the department of Microbiology, Mysore Medical College &
Research Institute, Mysore. Samples were received from Cheluvamba hospital
NICU over a period of 3 years from December 2007 to December 2010.
Cases included in our study
were neonates less than 28 days with clinical diagnosis of septicaemia.
Infections within 7 days of birth were considered early onset septicaemia
(EOS) and infections between 7 to 28 days were late onset septicaemia
(LOS).5 Blood samples were subjected to further processing
in our Microbiology lab according to standard methods.6
All the samples were processed
for blood culture and isolates were initially identified by colony morphology,
Gram stain, catalase, oxidase, slide coagulase, tube coagulase test
(read after 4-24 hours).1 Gram negative isolates were further
identified by standard biochemical reactions and antibiotic susceptibility
pattern was studied.7
In babies whom CoNS was isolated
in blood culture, a repeat sample was taken and reconfirmed for the
isolate. Biotyping of CoNS was done by the following panel of tests
– fermentation of mannose, xylose, sucrose, maltose, lactose, novobiocin
sensitivity, urease, nitrate reduction test, ornithine decarboxylase test.7
The antibiotic susceptibility
of the isolates was determined by disk diffusion method on Muller Hinton
agar using antibiotics at the specific absolute concentration using
HiMedia disks. Methicillin resistance was determined using cefoxitin
30µg disk.
A total of 2256 blood samples
received from NICU to the department of Microbiology were processed
for aerobic culture. 1587 samples were positive for blood culture. Among
1587 isolates, 1425 were from EOS and 162 from LOS. CoNS 587(36.98%)
was the most common pathogen isolated in both EOS 523(36.70%) and LOS
64(39.50%) cases. Staphylococcus epidermidis 234(39.86%) was
the commonest CoNS species.
|
Table
1: Showing frequency of isolates in neonatal septicaemia |
|
Isolates |
EOS |
LOS |
| No |
% |
No |
% |
| CoNS |
523 |
36.70 |
64 |
39.50 |
| Klebsiella
species |
276 |
19.36 |
44 |
27.16 |
| Escherichia
coli |
189 |
13.26 |
- |
- |
| Staphylococcus
aureus |
153 |
10.73 |
21 |
12.96 |
| Acinetobacter
species |
125 |
8.70 |
4 |
2.46 |
| Candida
species |
112 |
7.85 |
20 |
12.34 |
| Pseudomonas
species |
57 |
4.00 |
4 |
2.46 |
| Enterobacter
species |
49 |
3.43 |
6 |
3.70 |
| Enterococci
species |
29 |
2.03 |
4 |
2.46 |
| Total |
1425 |
|
162 |
|
|
Table 02: Showing frequency
of species of Coagulase negative Staphylococci |
|
CONS species |
N=587 |
% |
| Staphylococcus
epidermidis |
234 |
39.86 |
| Staphylococcus
haemolyticus |
84 |
14.31 |
| Staphylococcus
hominis |
65 |
11.07 |
| Staphylococcus
capitis |
58 |
9.88 |
| Staphylococcus
cohnii |
46 |
7.83 |
| Staphylococcus
simulans |
34 |
5.79 |
| Staphylococcus
xylosus |
29 |
4.94 |
| Untyped |
37 |
6.30 |
|
Table 3: Antibiotic
susceptibility pattern |
|
Isolates
n= 587 |
Percentage susceptible (%) |
|
A (10µg) |
E (15µg) |
Cd (2µg) |
Ak (30µg) |
G (10µg) |
Cf (5µg) |
Co (25µg) |
C (30µg) |
Lz (30µg) |
T (10µg) |
MSCoNS
n=301 |
2.15 |
4.30 |
4.83 |
60.75 |
34.40 |
65.59 |
44.08 |
8.45 |
89.17 |
45.32 |
MRCoNS
n=286 |
0 |
4.19 |
8.74 |
16.78 |
5.24
|
14.68 |
11.18 |
8.39
|
60.19 |
29.13 |
|
Note: MS-CoNS = methicillin
sensitive CoNS, A=ampicillin, Ak=amikacin, Co=cotrimaxazole, E=erythromycin,
G=gentamycin, C=chloramphenicol, Cd=clindamycin, Cf=ciprofloxacin, Lz=linezolid,
T=tetracycline. |
Methicillin resistance
was seen in 286(48.72%) of CoNS isolates. Also we noted increasing methicillin
resistance over years. MRCoNS prevalence during 2008, 2009 & 2010
were 41.57%, 47.0% and 57.36% respectively. Methicillin resistant CoNS
were mostly sensitive to linezolid 58(20.27%), amikacin 48(16.78%),
ciprofloxacin 42(14.68%) and were totally resistant to ampicillin 100%.
The infections in neonates
are most frequent and habitually more seriously associated with high
mortality.8 CoNS is increasingly being implicated as a significant
nosocomial pathogen, so many reviewers have emphasised the need for
species identification. Species identification is important in monitoring
the reservoir and distribution of CoNS involved in nosocomial infections.1
CoNS are further gaining importance
due to increase in resistance rates to betalactam antibiotics and multiresistance.
MRCoNS have become the predominant pathogen in hospitalised patients
with the number of infections increasing dramatically .8
MRCoNS are the source of resistance gene to other Gram positive cocci including Staphylococcus aureus
in hospital settings.4
In our study an attempt was
made to retrospectively analyse the trends of occurrence of MRCoNS in
neonatal septicaemia cases. In our study CoNS was the commonest isolate,
36.98% followed by Klebsiella species, 22.45% and Escherichia coli,
19.45%. This is in concordance with the reports of Shahsenam Gheibi
et al 5, reported causes of neonatal septicaemia as CoNS
from EOS – 48.8%, LOS – 69.8% followed by Klebsiella, Escherichia
coli & Staphylococcus aureus. However Nalini et al
9 have reported predominance of Gram negative septicaemia, 58.5%
over Gram positive cocci, 41.5%. Gupta B et al10 in their
study over a period of 4 yrs reported an increase in incidence of neonatal
septicaemia caused by CoNS from 20% to 35%.
Shubra Singh et al 3
have reported common CoNS species as Staphylococcus epidermidis
40%, Staphylococcus haemolyticus 12% which is similar to that
seen in our study of Staphylococcus epidermidis 39.86% and
Staphylococcus haemolyticus 14.31%.
Of the 587 CoNS isolates 286
(43.72%) were methicillin resistant. Amit Jain et al 11
reported 66% MR-CoNS from neonatal septicaemia.
In our study there was an increase
in prevalence of MR-CoNS over a period of 3 yrs from 41.57% to 57.36%.
Many other authors also have reported increasing trend of CoNS in neonatal
sepsis.12-14 MR-CoNS also showed increased resistance
even to non betalactam antibiotics thereby narrowing the therapeutic
options. Periodic surveillance of the causative agents and their antibiotic
profile is essential for effective management of neonatal septicaemia.
Appropriate antibiotic therapy would minimise the risk of severe morbidity
and mortality besides decreasing the emergence of multidrug resistant
organisms by rational antibiotic use.5
In view of the above facts
that in our study we have noticed an increase in prevalence of MR-CoNS
in neonatal septicaemia and increase in their resistance pattern, it
is necessary to periodically review the strategy of antibiotic usage.
- Sundaram V, Kumar P, Dutta
S etal . Blood culture confirmed bacterial sepsis in neonates in a north
Indian tertiary care center: Changes over last decade. Jpn J Infect Dis 2009;62:46-50.
- Kuruvilla KA, Pillai S, Jesudason
M et al. Bacterial profile of sepsis in a neonatal unit in south India. Indian
Paediatr J 1998;35:851-858.
- Singh S, Banerji G, Agarwal
SK et al. Simple method for speciation of clinically significant CoNS
& antibiotic/resistant pattern in NICU of tertiary care center .Biomedical Research
April 2008;19(2):1-6.
- Verhoef J, Fluit AC, Schimtz FJ. Staphylococci and other Micrococcaceace. In Cohen J, Powderely WG, Opal SM etal.
(Editors). Text book of Infectious diseases. Vol. 2. 2nd ed. Mosby pub., Edinburg. 2004.
pp 2123.
- Gheibi S, Fakoor Z, Karamayyar
M et al. CoNS: The most common cause of neonatal septicaemia
in Urmia, Iran. Iran J Pediatr Sep 2008;18(3):237-243.
- Colle JG, Maer W. Culture of bacteria. In Colle JG, Fraser AG, Marmion BP, Simmons A.
(Editors). Mackie & MacCartney Practical
Medical Microbiology. 14th ed. Churchill Livingstone, New York, 2007. pp 121-124.
- Koneman E. Staphylococci & related Gram positive cocci.
In Winn W Jr, Allen S, Janda W, Koneman E, Procop G, Woods G. (Editors). Koneman's Color atlas & text book of diagnostic
microbiology. 6th ed. Lippincott Williams & Wilkins, Edinburg. 2006. pp
649-655
- Khadri H, Alzohairy
M. Prevalence & antibiotic susceptibility pattern of methicillin resistance
& CoNS in a tertiary hospital in India. Ind J medicine & Med Scien
April 2010;2(4):116-120.
- Naliniagnihotri, Kaistha
N, Gupta V. Antimicrobial susceptibility of isolates from neonatal septicaemia.
Jpn J Infect Dis
2004;57:273-275.
- Gupta B et al. Changing Patterns
of Blood Borne Sepsis in Special Care
Baby Unit, Khoula Hospital. OMJ. 2010(25); 100-103.
- Amitajain, Agarwal J,
Banswal
S. Prevalence of methicillin resistant, CoNS in neonatal
intensive care units: findings from a tertiary care hospital in India. Med
Microbiol 2004;53:941-944.
- Stoll B, Gordon J. Late onset septicaemia in VLBW neonates
A report from the National
institute of child health & human development, neonatal research network. J
Pediatr
1996;129:63-71.
- Sohn A, Garrett D, Sinkowitz, Cochran
R. Prevalence of nosocomial infections in NICU patients: results from the first national point prevalence survey.
J Pediatr. 2001;136:821-827.
- Koksal F, Yasar H, Samarti
M. Antibiotic resistant pattern of CoNS from blood cultures of septicaemia in Turkey.
J Microbiol Res 2007;16:31-34.
|
