RESUMO
Burkholderia cenocepacia complex is associated with high transmissibility, virulence, and poor prognosis in cystic fibrosis (CF) patients. However, extrapulmonary infections are rare. We investigated the genome of a B. cenocepacia IIIA isolated from a liver abscess in a Brazilian CF patient and compared it to strain J2315. The whole genome was sequenced, and contigs were annotated by Rapid Annotation using Subsystem Technology. The Pathosystems Resource Integration Center was used to map antimicrobial and virulence genes. The genomic island (GIs) analysis was performed using two prediction methods, and the presence of putative plasmids and insertion sequences (ISs) was investigated. The isolate was confirmed as B. cenocepacia IIIA to ST-28 (ET12 lineage). A total of 64 genes for antimicrobial resistance and 47 genes related to virulence were identified. Among the virulence factors, there was a predominance of factors related to the invasion mechanism, to the flagellar biosynthesis protein, and to the RNA polymerase sigma factor for flagellar operon (cdpA). Two IS families (IS3 and IS5) and only one plasmid were found. On average 56 GIs were predicted by at least one of the methods applied. Comparative analysis showed resistance mechanisms and virulence factors revealing invasive determinants used by B. cenocepacia IIIA (ET12) in the process of disease spread to other infection sites (extrapulmonary) of highly virulent strains in CF patients.
Assuntos
Infecções por Burkholderia/microbiologia , Burkholderia cenocepacia/genética , Fibrose Cística/microbiologia , Genoma Bacteriano/genética , Abscesso Hepático/microbiologia , Adolescente , Brasil , Infecções por Burkholderia/complicações , Burkholderia cenocepacia/classificação , Burkholderia cenocepacia/isolamento & purificação , Fibrose Cística/complicações , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Feminino , Genes Bacterianos/genética , Ilhas Genômicas/genética , Humanos , Abscesso Hepático/complicações , Plasmídeos/genética , Fatores de Virulência/genéticaRESUMO
Burkholderia cepacia complex (Bcc) comprises 24 related species genetically distinct, associated with high mortality in cystic fibrosis (CF) patients. Due to a high level of similarity among Bcc species, accurate identification has been problematic, and most conventional and automated phenotypic tests have shown low accuracy. We evaluated accuracy of MALDI-ToF MS decreasing the cut-off score value to distinguish Bcc species compared to recA gene sequencing. A total of 145 Bcc isolates were analyzed. B. vietnamiensis (41.37%), B. cenocepacia IIIA (23.44%), B. multivorans (20%), B. cenocepacia IIIB (11.03%), and B. contaminans (2.75%) among other species were identified by recA sequencing. MALDI-ToF MS identified 100% of Bcc isolates at the genus level and 53.1% at the species level. By decreasing cut-off values for ≥1.70, the correct identification at the species level increased to 74.5%. MALDI-ToF MS proved to be useful at the genus level identification, but it still requires improvements that allow more precise identification, requiring continuous updates and addition of new spectra to its database. A review of interpretative criteria is a field to be explored with a large collection of Bcc species.