RESUMO
OBJECTIVES: Biofilm formation and bacterial adherence are important requirements for persistence, multidrug resistance and infection. The d-amino acids play a role as modulators of bacterial growth and persistence, though their ability to inhibit biofilms is much debated. In this study, we analysed the effects of 18 different d-amino acids on the pathogens Acinetobacter baumannii and Pseudomonas aeruginosa. METHODS: In vitro assays were carried out to analyse the effect of d-amino acids on bacterial growth, biofilm formation/disassembly, capacity to attach to eukaryotic cells and cellular death. In addition, in vivo assays were performed in mice, using experimental models of sepsis and pneumonia. RESULTS: Biofilm formation was inhibited in A. baumannii by d-His, d-Cys and d-Trp (35%-86%) at 2 mM and in P. aeruginosa by d-Cys, d-Trp and d-Tyr (10%-30%) at 4 mM. Attachment to the A549 human alveolar cells was reduced in A. baumannii by d-Cys, d-His, d-Met, d-Val and d-Ser, and in P. aeruginosa by d-Arg and d-Trp. Growth was inhibited in A. baumannii by d-Cys and d-Trp, and in P. aeruginosa by d-Trp. In virulence assays, incubation of alveolar cells infected with P. aeruginosa with d-Cys, d-Trp and d-Arg reduced cell death (56%-45%). However, no significant effect of d-amino acids was observed in vivo. CONCLUSIONS: Some d-amino acids can inhibit bacterial growth, biofilm formation and adherence to eukaryotic cells in A. baumannii and P. aeruginosa, and showed a protective effect against infection of alveolar cells with P. aeruginosa. Despite the fact that some considerable protection was observed in mice, survival differences between treated and control groups were not statistically significant.
Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/patogenicidade , Aminoácidos/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Acinetobacter baumannii/fisiologia , Aminoácidos/uso terapêutico , Animais , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Camundongos , Pneumonia Bacteriana/tratamento farmacológico , Pneumonia Bacteriana/microbiologia , Pneumonia Bacteriana/patologia , Pseudomonas aeruginosa/fisiologia , Sepse/tratamento farmacológico , Sepse/microbiologia , Sepse/patologia , Análise de Sobrevida , Virulência/efeitos dos fármacosRESUMO
We report here the draft genome sequences of Klebsiella pneumoniae strains Kp1803 and Kp3380 isolated during a large outbreak at A Coruña Hospital in Spain. The final genome assemblies for Kp1803 and Kp3380 comprise approximately 6.6 and 6.1 Mb, respectively, and both strains have G+C contents of 57.2%.