Abstract
Biofilm is recognized as a contributing factor to the capacity of Acinetobacter baumannii to persist and prosper in medical settings, but it is still unknown whether biofilms contribute to the spread of A. baumannii. In this study, the biofilm formation of 114 clinical A. baumannii isolates and 32 non-baumannii Acinetobacter isolates was investigated using a microtiter plate assay. The clonal relationships among A. baumannii isolates were assessed using pulsed-field gel electrophoresis and multilocus sequence typing, and one major outbreak clone and 5 other epidemic clones were identified. Compared with the epidemic or outbreak A. baumannii isolates, the sporadic isolates had significantly higher biofilm formation, but no significant difference was observed between the sporadic A. baumannii isolates and the non-baumannii Acinetobacter isolates, suggesting that biofilm is not important for the epidemic spread of A. baumannii. Of the multidrug-resistant (MDR) A. baumannii isolates in this study, 95.7% were assigned to international clone 2 (IC2) and showed significantly lower biofilm formations than the other isolates, suggesting that biofilm did not contribute to the high success of IC2. These findings have increased our understanding of the potential relationship between biofilm formation and the epidemic capacity of A. baumannii.
Highlights
Acinetobacter spp. are recognized as important opportunistic Gram-negative pathogens that are found mainly in immunocompromised patients
Biofilm was detected in 36% (41/114) of the clinical A. baumannii isolates and 81.3% (26/32) of the non-AB isolates
There have been some reports on the variations in biofilm formation capacity among clinical isolates of A. baumannii9–12, but the quantitative differences in biofilm formation among clinical isolates, in association with the epidemic capacity of strains, have been poorly investigated far
Summary
Acinetobacter spp. are recognized as important opportunistic Gram-negative pathogens that are found mainly in immunocompromised patients. Great diversity exists in the clinical importance of the various Acinetobacter species, with some being dominant as human pathogens and others merely acting as colonizing or environmental organisms. Some Acinetobacter species are highly successful in their capacity to cause outbreaks or to develop antibiotic resistance, among which A. baumannii is the most clinically important species, with the greatest number of healthcare-related outbreaks and reports of multidrug resistance. The number of multidrug-resistant (MDR) A. baumannii outbreaks is currently increasing worldwide. Great variation exists in the biofilm formation capacity of A. baumannii clinical isolates. Whether the variation in biofilm formation among strains determines their epidemic differences is still unknown. The biofilm formations were investigated for a large set of A. baumannii and non-baumannii Acinetobacter (non-AB) isolates that differed in terms of their epidemicity and drug resistant level
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call