RESUMO
OBJECTIVE: The objective of this study was to investigate the carriage of 6 virulence-associated genes in Enterococcus faecalis isolates obtained from patients in 8 hospitals in Kuwait. MATERIALS AND METHODS: In total, 466 E. faecalis isolates were obtained from 313 urine samples, 68 wound swabs, 36 blood samples, 25 rectal swabs, 12 high vaginal swabs and 12 miscellaneous sources. Genes for gelatinase(gelE),aggregation substance (aggA), hemolysin activation factor (cylA), enhanced expression of pheromone (eep), enterococcal surface protein (esp), and E. faecalis endocarditis antigen A (efaA) were detected in PCR assays. RESULTS: Of 466 isolates, 423 (90.8%) were positive for 1 and up to 5 genes. However, none of the genes was detected in all of the isolates. The prevalence of the individual genes was eep: 31.9%; esp: 31.5%; gelE: 28.5%; efaA: 27.9%; aggA: 23.4%, and cylA: 18.5%. Of the 423 positive isolates, 148 (34.9%) were positive for 2 genes and 52 (12.3%), 15 (3.5%) and 5 (0.9%) isolates were positive for 3, 4 and 5 virulence genes, respectively. The efaA and esp combination was detected in isolates from all clinical sources. CONCLUSION: The study showed a high prevalence of virulence genes in E. faecalis isolated in Kuwait hospitals. The absence of a dominant gene in all of the isolates suggests that infections by E. faecalis may require the involvement of multiple virulence factors.
Assuntos
Proteínas de Bactérias/genética , Enterococcus faecalis/genética , Enterococcus faecalis/patogenicidade , Fatores de Virulência/genética , Antígenos de Bactérias , Proteínas de Bactérias/isolamento & purificação , Primers do DNA , Enterococcus faecalis/isolamento & purificação , Gelatinases/genética , Gelatinases/isolamento & purificação , Infecções por Bactérias Gram-Positivas , Fatores de Hemolisina/genética , Fatores de Hemolisina/isolamento & purificação , Humanos , Kuweit , Proteínas de Membrana/genética , Proteínas de Membrana/isolamento & purificação , Feromônios/genética , Feromônios/isolamento & purificação , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genéticaRESUMO
Exosubstances (cohemolysins) produced by Streptococcus agalactiae (CAMP-factor) and Streptococcus uberis (Uberis-factor) showing hemolytic synergism with beta-lysin produced by Staphylococcus aureus were compared. Cohemolytic activity was evaluated in the supernatants of bacterial cultures, before and after ammonium sulfate precipitation. Sheep erythrocytes sensitized with beta-lysin were used as substrate. The assays were performed in microtiter plates and results were expressed as cohemolytic units/ml. Maximum cohemolytic activity was detected, respectively, after 8 h and 14 h of growth in Columbia broth in S. uberis and S. agalactiae cultures. Cohemolytic activities of both microorganisms showed similarities when submitted to various physical and chemical treatments. They were significantly decreased by heating at 60 degrees C and 100 degrees C, or in presence of trypsin, and were abolished in the presence of Tween 20. Activities were found to be stable in crude supernatants and concentrated preparations maintained at -20 degrees C for 3 months. Differences were related to levels of activity and kinetics of detection during the growth cycle. The results indicate the proteic nature, at least in part, of the Uberis factor. Analysis by PAGE in the presence or absence of SDS allowed us to correlate Uberis activity with a protein band with apparent molecular mass of 42 kDa, while CAMP activity was associated with a protein band of 27 kDa.