Selection of colistin-resistant Acinetobacter baumannii isolates in postneurosurgical meningitis in an intensive care unit with high presence of heteroresistance to colistin

• Published in: Diagnostic microbiology and infectious disease 2009-10, Vol.65 (2), p.188-191
• Main Authors: Hernan, Rodriguez Carlos, Karina, Bombicino, Gabriela, Granados, Marcela, Nastro, Carlos, Vay, Angela, Famiglietti
• Format: Article
• Language: English
• Subjects: Acinetobacter; Acinetobacter baumannii; Acinetobacter baumannii - classification; Acinetobacter baumannii - drug effects; Acinetobacter baumannii - genetics; Acinetobacter baumannii - isolation & purification; Acinetobacter Infections - drug therapy; Acinetobacter Infections - microbiology; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Argentina; Bacterial Typing Techniques; Bacteriology; Biological and medical sciences; Cluster Analysis; Colistin; Colistin - pharmacology; Colistin - therapeutic use; Cross Infection - drug therapy; Cross Infection - microbiology; DNA Fingerprinting; DNA, Bacterial - genetics; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Fundamental and applied biological sciences. Psychology; Genotype; Heteroresistance to colistin; Hospitals, University; Humans; Infectious Disease; Infectious diseases; Intensive Care Units; Internal Medicine; Male; Medical sciences; Meningitis, Bacterial - drug therapy; Meningitis, Bacterial - microbiology; Microbiology; Miscellaneous; Ribotyping; Selection, Genetic; Young Adult
• ISSN: 0732-8893; 1879-0070
• DOI: 10.1016/j.diagmicrobio.2009.05.019

Abstract Colistin heteroresistance in Acinetobacter baumannii (Ab) has been reported, but the clinical impact and the antimicrobial treatment have not been established yet. We observed the selection intratreatment with colistin of Ab colistin-resistant strains from a colistin-heteroresistant isolate in one patient with postneurosurgical meningitis. The presence and the genetic relationship of heteroresistant Ab isolates from intensive care units (ICUs) obtained in the same period of the case report were analyzed. Twenty-eight isolates from patients admitted to the ICUs of an Argentinian university hospital during June to December 2004 were evaluated. Genomoespecie was determined by amplified ribosomal DNA restriction analysis, and genetic similarity among the strains was determined by pulsed-field electrophoresis. Colistin heteroresistance was observed in 46, 4% of these isolates. The majority belonged to clones previously identified as I and III.