Achromobacter species, an emerging cause of bacteremia in tertiary healthcare facilities in Egypt

During our laboratory routine, we detected Gram-negative, motile, aerobic, oxidase- and catalase-positive, lactose non-fermenting bacilli during microbial isolation from blood cultures of immune compromised patients. Our study investigates this phenomenon.

Blood culture results from 1000 samples were taken during febrile attacks in immune compromised patients in adult intensive care units (AICUs), pediatric and neonatal intensive care units (PICUs and NICUs, respectively), liver and kidney departments, and oncology and hematology departments in a tertiary healthcare facility in Cairo, Egypt. The blood cultures were processed in the microbiology laboratory and incubated in an automated system. An automated system was also used to identify the species in positive cultures and perform antimicrobial susceptibility testing. Achromobacter sp. were identified and isolated according to their morphological and biochemical characteristics.

Of one thousand blood cultures performed, 310 were positive (Gram-negative: 195, 63%; Gram-positive: 105, 34%; fungi: 10, 3%). Of these positive cultures, 16 (5.2%) were positive for Achromobacter sp., the most common being Achromobacter xylosoxidans (15/16, 93.75%), while A. dentrificans was identified in one case (6.25%). Among those affected, 37.5% were patients with hematological malignancies, 6.25% had organ transplants, 56.5% were in the ICUs (25% were in AICU, 18.8% in the PICU, and 12.5% in the NICU). Achromobacter sp. were resistant to cefepime, aminoglycosides, and fluoroquinolones. Central venous catheter infection occurred in 13 (81.25%) cases.

Our findings open discussion concerning Achromobacter sp. as an opportunistic pathogen in immune compromised patients and contribute to the development of future treatment approaches.