Emergence of colistin and carbapenem-resistant Acinetobacter calcoaceticus-Acinetobacter baumannii (CCR-Acb) complex in a neurological intensive care unit followed by successful control of the outbreak

Background: Colistin and carbapenem-resistant Acinetobacter calcoaceticus- Acinetobacter baumannii complex (CCR-Acb complex) was isolated from two consecutive patients in the neurological intensive care unit (NICU). An urgent reaction to this desperate situation was required. Patients and methods: Screening cultures were taken from the other patients sharing the NICU with index patients and repeated periodically. NICU was closed for new admissions. Infection control precautions (ICP) such as hand hygiene, cohorting patients colonized with CCR-Acb complex, cohorting the staff caring for these patients, daily bathing with chlorhexidine gluconate impregnated clothes, using gowns when contacting with patients and patient care area, and sodium hypochlorite tablets for environmental cleaning were enforced. Results: Screening cultures revealed carbapenem-resistant Acb complex in 12 out of 32 patients and 8 of them were colonized with CCR-Acb complex. NICU was opened for new admissions one month later. No further new cases with CCR-Acb complex were detected by screening cultures after 6 weeks with enforcement of ICP. Moreover, the rate of nosocomial infections caused by other multi-drug resistant Gram-negative bacilli (MDR-GNB) decreased significantly when rates before and after closing the NICU were compared. Conclusion: ICP were effective not only to limit the spread of CCR-Acb complex but also decreased the incidence of other MDR-GNB infections when applied adequately. Keywords: Acinetobacter baumannii, Carbapenem resistance, Colistin resistance, Intensive care unit, ICU