Prevalence of antimicrobial resistance among gram-negative isolates in an adult intensive care unit at a tertiary care center in Saudi Arabia.
OBJECTIVE
Patients in the ICU have encountered an increasing emergence and spread of antibiotic-resistant pathogens. We examined patterns of antimicrobial susceptibility in gram-negative isolates to commonly used drugs in an adult ICU at a tertiary care hospital in Riyadh, Saudi Arabia.


METHODS
A retrospective study was carried out of gram-negative isolates from the adult ICU of King Fahad National Guard Hospital (KFNGH) between 2004 and 2009. Organisms were identified and tested by an automated identification and susceptibility system, and the antibiotic susceptibility testing was confirmed by the disk diffusion method.


RESULTS
The most frequently isolated organism was Acinetobacter baumannii, followed by Pseudomonas aeruginosa, Escherichia coli, Klebsiella pnemoniae, Stenotrophomonas maltophilia, and Enterobacter. Antibiotic susceptibility patterns significantly declined in many organisms, especially A baumannii, E coli, S marcescens, and Enterobacter. A baumannii susceptibility was significantly decreased to imipenem (55% to 10%), meropenem (33% to 10%), ciprofloxacin (22% to 10%), and amikacin (12% to 6%). E coli susceptibility was markedly decreased (from 75% to 50% or less) to cefuroxime, ceftazidime, cefotaxime, and cefepime. S marcescens susceptibility was markedly decreased to cefotaxime (100% to 32%), ceftazidime (100% to 35%), and cefepime (100% to 66%). Enterobacter susceptibility was markedly decreased to ceftazidime (34% to 5%), cefotaxime (34% to 6%), and pipracillin-tazobactam (51% to 35%). Respiratory samples were the most frequently indicative of multidrug-resistant pathogens (63%), followed by urinary samples (57%).


CONCLUSIONS
Antimicrobial resistance is an emerging problem in the KFNGH ICU, justifying new more stringent antibiotic prescription guidelines. Continuous monitoring of antimicrobial susceptibility and strict adherence to infection prevention guidelines are essential to eliminate major outbreaks in the future.
Al Johani
Sameera M
SM
King Abdulaziz Medical City, Riyadh, Saudi Arabia. johanis@ngha.med.sa
Akhter
Javed
J
Balkhy
Hanan
H
El-Saed
Ayman
A
Younan
Mousaad
M
Memish
Ziad
Z
D040981:Acinetobacter baumannii / Q000187:drug effects / Q000302:isolation & purification; D000328:Adult; D000583:Amikacin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002939:Ciprofloxacin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects / Q000302:isolation & purification; D005839:Gentamicins / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification*; D006761:Hospitals; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D007362:Intensive Care Units; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D010878:Piperacillin / Q000494:pharmacology; D000077725:Piperacillin, Tazobactam Drug Combination; D015995:Prevalence; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D012189:Retrospective Studies; D012529:Saudi Arabia / Q000453:epidemiology; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology; D047090:beta-Lactams / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D047090:beta-Lactams; D000077725:Piperacillin, Tazobactam Drug Combination; D002939:Ciprofloxacin; D015378:Imipenem; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D000583:Amikacin; D010397:Penicillanic Acid; D010878:Piperacillin