Biofilm formation of panresistant Klebsiella pneumoniae

Relationship between biofilm formation and antibiotic resistance of Klebsiella pneumoniae and updates on antibiofilm therapeutic strategies

Klebsiella pneumoniae is a Gram-negative bacterium within the Enterobacteriaceae family that can cause multiple systemic infections, such as respiratory, blood, liver abscesses and urinary systems. Antibiotic resistance is a global health threat and K. pneumoniae warrants special attention due to its resistance to most modern day antibiotics. Biofilm formation is a critical obstruction that enhances the antibiotic resistance of K. pneumoniae. However, knowledge on the molecular mechanisms of biofilm formation and its relation with antibiotic resistance in K. pneumoniae is limited. Understanding the molecular mechanisms of biofilm formation and its correlation with antibiotic resistance is crucial for providing insight for the design of new drugs to control and treat biofilm-related infections. In this review, we summarize recent advances in genes contributing to the biofilm formation of K. pneumoniae, new progress on the relationship between biofilm formation and antibiotic resistance, and new therapeutic strategies targeting biofilms. Finally, we discuss future research directions that target biofilm formation and antibiotic resistance of this priority pathogen.

In vitro activities of antibiotic combinations against mature biofilms of ventilator-associated pneumonia isolates

Background: The authors aimed to determine the efficacy of frequently used antibiotics, alone or in combination, against biofilms of ventilator-associated pneumonia isolates. Materials & methods: The authors determined the MICs, minimum biofilm inhibitory concentrations and minimum biofilm eradication concentrations of meropenem, ciprofloxacin and colistin as well as their combinations against planktonic forms and biofilms of Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii clinical isolates. Results: Generally, the minimum biofilm inhibitory concentrations and minimum biofilm eradication concentrations of the antibiotics were 1000-fold higher than their MICs, and synergy was provided by different concentrations of meropenem-colistin and meropenem-ciprofloxacin combinations with checkerboard and time-kill curve methods. Conclusion: The combination of meropenem and ciprofloxacin seems to be a good candidate for the treatment of biofilm-associated infections; none of the concentrations obtained as a result of the synergy test were clinically significant.