Antimicrobial resistance among non-fermenting Gram-negative bacteria in Saudi Arabia

Non-fermentative Gram-negative bacilli (non-fermenters) can cause serious healthcare-associated infections and are often resistant to multiple antibiotics. We examined resistance rates among these bacteria from different regions of Saudi Arabia.

A cross-sectional study between January and December 2009 examined 8908 clinical non-fermenters from 24 hospitals across Saudi Arabia. Susceptibility testing was monitored to ensure compliance with CLSI guidelines, but the antibiotics tested were at the hospitals' discretion.

Out of the 8908 non-fermenters, most were Pseudomonas aeruginosa (72.9%), followed by Acinetobacter baumannii (25.3%) and Stenotrophomonas maltophilia (1.8%). Resistance rates among P. aeruginosa were: polymyxin B, 2.2%; imipenem, 15.9%; ciprofloxacin, 22.0%; amikacin, 22.9%; and gentamicin, 31.2%. Resistance rates among A. baumannii were: imipenem, 5.4%; polymyxin B, 13.2%; ciprofloxacin, 64.0%; trimethoprim/sulfamethoxazole, 73.8%; amikacin, 76.9%; and gentamicin, 77.8%. Resistance rates among S. maltophilia were: polymyxin B, 6.9%; trimethoprim/sulfamethoxazole, 20.5%; and ciprofloxacin, 38.9%. There was major variation in resistance rates between geographical regions.

Resistance rates among non-fermenters were high in Saudi Arabia and were variable among regions.