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Ind. J. Sci. Res. and Tech. 2013 1(1):35-37/Berry et al ISSN:-2321-9262 (Online)
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Research Article
ACINETOBACTER: AN OPPORTUNISTIC UROPATHOGEN
*Bhumika Berry, Cherry Kedia, Lilly Karamdeep Grewal and Mona Goyal
Dr. Lal Path Labs, Ludhiana, Punjab, India ABSTRACT
The present study was conducted over a period of one year in the Microbiology Laboratory, Dr.Lal Path Labs.,
Sarabha Nagar, Ludhiana. A total of 1,578 urine samples received from the patients suspected of having urinary
tract infection were processed. The aim was to assess the prevalence of Acinetobacter as an uropathogen and to find
out its antimicrobial profile.
Out of 1,578 urine samples processed 1,223(77.50%) yielded positive results. Out of 1,223 positive samples, the
prevalence of Acinetobacter was 6.38%.The other common isolates were Escherichia coli (61.08%) Staphylococcus
aureus (10.79%) and Streptococcus faecalis (08.59%).
The antimicrobial susceptibility pattern for the isolated Acinetobacter species showed enhanced degree of resistance
towards Ampicillin (97.44%), Norfloxacin (93.59%), Cefepime (89.74%), Ciprofloxacin (87.18%), Levofloxacin
(87.18%) and Cotrimoxazole (84.62%). There was maximum sensitivity towards Cefoparazone/Sulbactum
combination (78.20%) followed by that towards Amikacin (58.97%).Other antibiotics with comparatively
appreciable susceptibility degree included Cefotaxime (43.59%) and Nitrofurantion (47.43%).
The conclusion is that there is high prevalence of multidrug resistant Acinetobacter as a uropathogen amongst other
urinary isolates. The resistance might be plasmid mediated and might be due to production of extended spectrum
beta lactamases.Hence antibiograms should be prepared periodically to be followed by the clinicians who treat the
patients having urinary tract infections.
Key Words: Acinetobacter, Uropathogen, CLED Medium and Amikacin
INTRODUCTION
Acinetobacter, a member of the family Gammaproteobacteria, is widely distributed in nature. It acts as an
opportunistic pathogen. The genus Acinetobacter has two important pathogenic species i.e. Acinetobacter antitratus
and Acinetobacter lwoffi. These organisms are gram negative, strict aerobes, non motile, catalase positive, and
oxidase negative which often exist as diplococcobacilli. These can grow on routine laboratory media.
These micro organisms are ubiquitous in nature and are highly resistant to various antimicrobials (Seifert et al.,
1993). Both communities acquired as well as nosocomial infections caused by Acinetobacter are upsurging today. It
has been noticed that at present, Acinetobacter species are the second most common gram negative bacilli
encountered in clinical specimens following the members of the family Enterobacteriaceae (Forbes et al., 1998).
Acinetobacter is associated with respiratory tract infections, urinary tract infections, meningitis, septicaemia,
endocarditis, wound infections, and burn infections.

MATERIALS AND METHODS
The present study was conducted in the Microbiology Laboratory, Dr.Lalpath Labs., Sarabha Nagar, Ludhiana to
determine the prevalence of Acinetobacter in urinary tract infection (UTI). A total of 1,578 urine samples received
from the patients suspected of having UTI were processed. This study is partly retrospective and partly prospective
from 21st August, 2008 to 20thAugust, 2009.
Each patient was advised to submit mid stream urine sample collected aseptically in a sterile container. A standard
sized loop was used for inoculation of the sample on Cystine Lactose Electrolyte Deoxycholate Agar (CLED)
medium. The plates were incubated at 37°C for 24-48 hours. Then the culture plates with growth of organisms were
labeled into three categories as follows:
No significant growth.
Growth with doubtful significance.
Significant growth of bacteria.
This grading was based on Kass concept of significant bacteriuria (Ananthanarayan & Paniker, 2009). The culture
plates showing no significant growth were not processed further. The organisms on the other plates showing growth
with doubtful significance and those showing significant growth were further processed. Bacterial growth was
identified based on the colony morphology, Gram staining and various biochemical tests (Goderands & Lopec,
2003). The antibiotic sensitivity test was done for all the isolates using Kirby Bauer disc diffusion method (Mastsen
et al., 1969).
Ind. J. Sci. Res. and Tech. 2013 1(1):35-37/Berry et al ISSN:-2321-9262 (Online)
Online Available at: http://www.indjsrt.com
Research Article
RESULTS
Out of 1578, urine samples processed, 1,223 (77.50%) samples yielded positive results. Amongst the positive
samples, E.coli (61.08%) was the commonest isolate followed by Staphylococcus aureus (10.79%). Acinetobacter
isolates were 78 (6.38%). Table 1 shows number and percentage of all the isolates obtained.
Table 1: Various isolates obtained on culture of urine samples
Organisms
Percentage
Total samples=1578; No. of positive samples=1223

Table 2: Vntimicrobial sensitivity profile of seventy eight acinetobacter isolates
Antibiotics
Disc strength(mcg)
No. Sensitive
Percentage

Antimicrobial susceptibility pattern of Acinetobacter isolates has been depicted in Table 2. It has shown marked
resistance towards commonly used antibiotics like ampicillin, norfloxacin, cefepime, ciprofloxacin, levofloxacin and
cotrimoxazole. The Acinetobacter isolates here show maximum sensitivity towards cefoparazone/sulbactum
combination which is 78.20% followed by that towards amikacin (58.97%), nitrofurantion (47.43%) and cefotaxime
(43.58%) Even piperacillin/ tazobactum combination is not suitable for this uropathogen since there is only 19.23%
sensitivity exhibited by this combination.

DISCUSSION
Acinetobacter species exist as commensals on the skin of groin and axilla in man. Acting as opportunistic pathogens,
these cause varied infections like pneumonia, bronchitis, UTI meningitis, septicaemia, endocarditis and so on. The
present study emphasizes the role of Acinetobacter as an uropathogen. In this study the prevalence of Acinetobacter
in UTI has been 6.38%. In a study from Nagpur (Supriya et al., 2004), the prevalence of Acinetobacter in UTI is
Ind. J. Sci. Res. and Tech. 2013 1(1):35-37/Berry et al ISSN:-2321-9262 (Online)
Online Available at: http://www.indjsrt.com
Research Article
reported as 1.47%, whereas another study by Anbumani and Mallika(2007) from Chennai have reported it to be
6.1%.So different prevalence rates prevail in different geographical regions.
Antimicrobial susceptibility pattern of the isolated Acinetobacter species is alarming with a marked resistance to
majority of the antibiotics i.e. ampicillin, norfloxacin, cefepime, ciprofloxacin, levofloxacin, cotrimoxazole
pipreracillin/tazobactum combination. Multidrug resistant Acinetobacter species have been reported frequently
(Pearce et al., 1993; Berry et al., 2005; Baaners et al., 2005). While focusing on norfloxacin, an antibiotic commonly
used to treat UTI, we find a poor response with 6.41%sensitivity pattern. Ciprofloxacin was considered highly
effective in treatment of UTI because of its concentrating ability in urine and high renal clearance (Paddock & Wise,
1989). But in the present study it has shown a very poor response which is again a matter of concern. With wide
spread use of fluoroquinolones there have been reports of evolving bacterial resistance towards Ciprofloxacin (the
most frequently used fluoroquinolone) ranging between 10% and 53% (Bhat et al., 1996).
There is high degree of resistance towards various third degree cephalosporins except that for cefotaxime for which
sensitivity percent is 43.59%.Even for Cefepime, a fourth generation cephalosporin, there is a very poor response as
only 10.27%.Acinetobacter isolates are being susceptible to it. Majority of the Acinetobacter isolates are resistant
towards two, three or all the four third generation cephalosporins used in the antibiotic testing panel. It indicates that
majority of the strains are extended spectrum beta lactamses (ESBL) producers. The production of beta lactamases
may be of plasmid origin (Yu et al., 2002).
Transfer of genetic material amongst the bacteria promotes the plasmid mediated production of beta lactamases and
a transferable plasmid codes for resistant determinants to other antimicrobials as well. Hence multidrug resistance is
more common in ESBL producers. Also Imipenem, the broad spectrum new antimicrobial has shown only 28.21%
sensitivity towards this fastidious micro organism. It depicts progressive resistance pattern of this bacterium.
Hence we must prepare conventional antibiograms periodically to know the current antimicrobial status of various
uropathogens. Ideally we must wait for culture and sensitivity report for initiating the treatment of a patient with
UTI and if required, antibiogram can be consulted to begin the report in adversely diseased patients for whom we
cannot wait for the culture and sensitivity report that needs atleast 48-72 hours. Such antibiograms are again useful
in the UTI patients who cannot afford to get urine culture and sensitivity testing done or for the patients who stay in
the rural areas where such facilities are not available.

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