351 352 CLINICAL FEATURES OF ACINETOBACTER INFECTION  Indian Journal of Medical Sciences Indian Journal of Medical Sciences Indian Journal of Medical Sciences Indian Journal of Medical Sciences Indian Journal of Medical Sciences (INCORPORATING THE MEDICAL BULLETIN) VOLUME 60 SEPTEMBER 2006 NUMBER 9  ORIGINAL CONTRIBUTIONS CLINICAL AND DEMOGRAPHIC FEATURES OF INFECTION CAUSED BY ACINETOBACTER SPECIES SURESH G. JOSHI, GEETANJALI M. LITAKE*, MEENAKSHI G. SATPUTE, NILIMA V.TELANG, VIKRAM S. GHOLE*, KRISHNA B. NIPHADKAR ABSTRACT BACKGROUND: Recently, Acinetobacter emerged as an important pathogen and the prevalence of isolation has increased since the last two decades worldwide. AIMS: To determine Acinetobacter incidence, their clinical demography, antibiotyping and speciation. SETTINGS AND DESIGN: A study of the clinical samples submitted to microbiology laboratory of a teaching hospital over a period of 3 years (December 1994 through November 1997). MATERIALS AND METHODS: Identification, speciation and antibiotyping were performed for the isolates of Acinetobacter recovered from infective samples. Clinical demographic characteristics were studied retrospectively. RESULTS: Total 510 of 5391 (9.6%) of isolates were Acinetobacter, responsible for 71.2% (363 of 510) monomicrobial and 28.8% (147 of 510) polymicrobial infections. The organism was responsible for 156 (30.6%) cases of urinary tract infection and 140 (27.5%) cases of wound infection and was most prevalent in the intensive care unit (30.8%, 140 of 455). The crude mortality rate due to multi-drug resistant Acinetobacter septicemia was 7.9% (36 of 455). The isolates could be classified into 7 species, with A. baumannii being most predominant. No peculiar pattern during antibiotyping was observed, but most of them were multi-drug resistant. CONCLUSION: Multi-drug resistant Acinetobacter nosocomial infection has emerged as an increasing problem in intensive care units of the hospital, responsible for 7.9% deaths. The analysis of risk factors and susceptibility pattern will be useful in understanding epidemiology of this organism in a hospital setup. Key words: Acinetobacter, antimicrobial resistance, hospital-acquired infection, nosocomial pathogen, risk-factor Correspondence Suresh G. Joshi, 91, Department of Infectious Diseases, Department of Clinical Microbiology, King Edward  Thomas Jefferson University Medical College, 1020 Locust  Memorial Hospital, and *Division of Biochemistry, Street, Room: JAH-314, Philadelphia, PA 19107, USA.  Department of Chemistry, University of Pune, India E-mail: surejoshi@yahoo.com  Acinetobacter  is ubiquitous, free-living and  fairly stable in the environment. Members of  the genus Acinetobacter are gram-negative  cocco-bacillus that emerge as significant  nosocomial pathogens in the hospital setting  and are responsible for intermittent outbreaks.  The incidence of outbreak is much more in  the regions where temperature is hot and  humid. The infection caused by Acinetobacter  is difficult to control due to multi-drug  resistance, which limits therapeutic options  in critically ill and debilitating patients  especially from intensive care units, where  their prevalence is most noted. One of the  species, Acinetobacter baumannii, is currently  the third commonest isolate from gram- negative sepsis in immunocompromized  patients, posing risk for high mortality. [1]  The  organism prefers moist environment;  therefore, colonization in healthy persons and  damaged tissue is also common. [2]  The infections caused by Acinetobacter  usually include pneumonia, septicemia,  wound sepsis, urinary tract infection,  endocarditis and meningitis. [3]  In addition to  hospitalized patients, community-acquired  Acinetobacter  infection is increasingly  reported these days. [4]  Although  epidemiological features and risk factors for  outbreaks of Acinetobacter  infection have  been described, there is a paucity of  information about Acinetobacter endemicity.  There is a significant difference in behavior  of this organism among isolates recovered  from various geographic locations. [5]  In our  study spread over a period of 3 years at a  tertiary care teaching hospital; we report the  significance of infections caused by  Acinetobacter  spp. and their biological  response towards antibiotic susceptibility  patterns.  MATERIALS AND METHODS Clinical specimens, bacterial isolates and Acinetobacter identification The study was carried out in a 600-bed  tertiary care hospital of Pune, a city from the  state of Maharashtra, located in western  India, during December 1994 through  November 1997. All clinical specimens were  initially processed by the routine microbiology  laboratory tests to separate the  nonfermenters from gram-negative bacilli and  eventually identified as acinetobacters. [6]  Typical colonies were enumerated, picked and  examined further. Acinetobacter was identified  by Gram staining, cell and colony  morphology, activity in the oxidation /  fermentation test, absence of motility and  negative oxidase and positive catalase  reactions. The transformation assay of Juni  was used to confirm the genus. [7]  Clinical features of cases of Acinetobacter infection The following clinical characteristics were  recorded: Sex, age, seasonal incidence,  duration of hospitalization, presence of  underlying disease(s) and risk factors, days  on previous antibiotic therapy, possible  source of infection and clinical outcome of  the disease [Table 1]. The same person  retrieved the case records. Standard  definitions as given by Center for Disease  Control and Prevention were used to  differentiate categories of infection and  ‘infection versus colonization,’ etc. [8]  All  standard precautions were taken to avoid  Indian J Med Sci, Vol. 60, No. 9, September 2006 Indian J Med Sci, Vol. 60, No. 9, September 2006