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Indian Journal of Medical Microbiology, Vol. 26, No. 1, January-March, 2008, pp. 81-83 Case Report Ochrobactrum anthropi septicaemia Arora U, Kaur S, Devi P Department of Microbiology, Government Medical College, Amritsar Date of Submission: 30-Oct-2006 Code Number: mb08020 Abstract Ochrobactrum anthropi is an emerging opportunist pathogen in immunocompromised patients. We report a case of septicaemia due to O. anthropi in an elderly male patient with coronary artery disease with severe left ventricular dysfunction admitted in the Intensive coronary care unit. Following intraaortic balloon pump (IABP) insertion, the patient developed a haematoma at the local site, which led to septicaemia. In spite of intensive treatment, the condition of the patient continued to deteriorate and he died on the seventh day. This infection with the microbiological characteristics useful for identification of the organism is described.Keywords: Ochrobactrum anthropi , nonfermenter, septicemia Ochrobactrum anthropi, formerly designated as Centers for Disease Control (CDC) groups Vd-1 and Vd-2, is an oxidase-positive, gram-negative, nonfermenting bacillus that oxidizes glucose and grows readily on MacConkey agar. It is an emerging pathogen in immunocompromised patients and is associated with implantation of foreign bodies particularly indwelling central venous catheters. [1] The organism is capable of survival in water and can adhere to the silicon material of catheters. [2] Acquisition of this pathogen via contaminated pharmaceuticals and puncture wounds has also been reported. [3] We report the clinical and microbiological characteristics of O. anthropi in a patient following intraaortic balloon pump (IABP) insertion. Case Report A 64-year-old male, a known case of hypertension, diabetes and coronary artery disease with left ventricular dysfunction, presented with severe chest pain and was admitted in the intensive coronary care unit. The patient was fully conscious at the time of admission. Laboratory investigations showed haemoglobin (Hb) 10 g/dL, total leucocyte count (TLC) 12,000/mm 3 , the myocardial form of creatine phosphokinase (CPK-MB) 190 IU/L, random blood sugar 200 mg/dL and blood pressure (BP) of 100/60 mm of Hg. Pulmonary oedema was observed in the chest X-ray. Echocardiography showed severe left ventricular dysfunction with LVEF (left ventricular ejection fraction) of 20%. Central venous line was inserted and the patient was started on inj. ciprofloxacin (100 mL intravenous, twice a day (IV bd)) and inj. cefazolin (1 g IV thrice a day ). Due to haemodynamic instability, the IABP was inserted through the left femoral artery. On the day after the insertion of the IABP, the patient started having a swelling at the local insertion site, which led to the formation of a haematoma. The IABP was removed from the left side and inserted through the right femoral artery and a compression bandage was applied at the local site of the haematoma. On the next day, the patient became febrile. The size of the haematoma increased in spite of the compression bandage for which surgical debridement of the wound was done. Infection was indicated by the laboratory investigations which showed that there was leucocytosis (TLC: 21,000 cells/mm 3 ) with a high neutrophil count (differential leucocyte count, DLC N 90 , L 8 , M 2 , E 0 ), Hb: 6 g/dL, platelets: 90,000/µL, blood urea: 80 mg/dL and serum creatinine: 2.1 mg/dL. Inj. tazact (2.5 g IV tds), inj. meropenem (1 g IV tds) and inj. metronidazole (100 mL IV tds) were added to the treatment regimen to combat the infection. Urine and blood were sent to the microbiology laboratory for culture and sensitivity. No growth of pyogenic organisms was found on culturing the urine. However, turbidity and haemolysis were seen in the blood culture bottle, which was further subcultured on blood agar and MacConkey agar media. Colonies about 1 mm in diameter, circular, low convex, smooth, shining, nonhaemolytic and having entire margins grew on blood agar medium. Mucoid, nonlactose fermenting colonies were found on MacConkey agar medium. On Gram staining, gram-negative bacilli with no specific arrangement were seen. The organism was motile, oxidase-positive, catalase-positive, nonfermenter (alkaline butt and alkaline slant on triple sugar iron (TSI) medium), utilized glucose, xylose and mannitol oxidatively on Hugh-Leifson oxidative/fermentative (OF) medium, hydrolyzed urea and reduced nitrate to nitrite. Esculin hydrolysis was not observed. The isolate was presumptively identified as O. anthropi, which was further confirmed by RapID NF Plus system (a combination of conventional tests and single substrate chromogenic tests based on the microbial degradation of specific substrates detected by various indicator systems). Antibiotic sensitivity was determined by Kirby Bauer′s disc diffusion method. The isolate was found to be sensitive to ciprofloxacin (1 µg/disc), sulbactam-cefoperazone (30 µg/75 µg/disc) and imepenam (10 µg/disc), moderately sensitive to tobramycin (10 µg/disc) and resistant to piperacillin (30 µg/disc), ticarcillin (75 µg/disc), cefotaxime (10 µg/disc), cefoperazone (75 µg/disc), amikacin (30 µg/disc), gentamicin (10 µg/disc) and aztreonam (30 µg/disc). In spite of intensive treatment, the condition of the patient continued to deteriorate and he died on the seventh day. Discussion Ochrobactrum anthropi is an aerobic, gram-negative bacillus widely distributed in aquatic environments. This organism rarely causes human infections but when encountered, it is frequently found to involve contaminated medical materials/devices and immunocompromised patients. It is generally believed that O. anthropi is the only pathogenic species in the genus Ochrobactrum that is most commonly encountered in clinical settings. Most reports of O. anthropi bacteraemia are associated with intravenous line infections. In the present study, the organism was isolated from an elderly male suffering from coronary artery disease and having multiple predisposing factors. The patient died of septicaemia following surgical debridement of the haematoma, which had developed due to invasive procedures performed in the hospital. Chertow has reported catheter-associated bacteraemia due to O. anthropi in a haemodialysis patient with unexplained fever. [4] Another study reports the clinical and microbiological characteristics of O. anthropi bacteraemia in 15 patients having serious underlying diseases. [1] Over a study period of two years, Kern et al. [5] have detected catheter-related bacteraemia due to O. anthropi in four patients of acute leukaemia as the underlying disease. A case of life-threatening septic shock that occurred in an otherwise healthy host after administration of a peripheral venous infusion of a solution contaminated with O. anthropi has also been reported. [6] O. anthropi appears to be an emerging opportunistic pathogen associated with the implantation of intravenous catheters or other foreign bodies in patients of debilitating illness. Although the organism seems to be of relatively low virulence, it can produce clinically significant, fatal infections in immunocompromised patients. Therefore, it is very important to implement effective methods of sterilization and infection control guidelines to prevent infection. References
Copyright 2008 - Indian Journal of Medical Microbiology |
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