Burkholderia cenocepacia, B. multivorans, B. ambifaria and B. vietnamiensis isolates from cystic fibrosis patients have different profiles of exoenzyme production.
Knowledge about the virulence mechanisms of species from the Burkholderia cepacia complex (BCC) is still limited. The genomovar heterogeneity and production of different virulence factors are likely to contribute to the variation in the clinical outcome observed in BCC-infected cystic fibrosis (CF) patients. Therefore, in this study we investigated the genetic polimorphism, the presence of genetic makers associated with virulence and transmissibility in BCC, and the profile of exoenzyme production of 59 BCC isolates obtained from 59 CF patients attending the reference CF centre in Rio de Janeiro, Brazil. The DNA sequence analyses of the recA gene allowed us to identify 40 of these 59 BCC species as being B. cenocepacia, 9 as B. vietnamiensis, 6 as B. multivorans and 4 as B. ambifaria. The assessment of the bacterial genetic polymorphism by PFGE revealed that B. cenocepacia and the B. multivorans isolates belonged to four and two different PFGE profiles with prevalence of two clones, A and B, respectively. All B. vietnamiensis and B. ambifaria belonged to only one PFGE profile (J and E, respectively). None of the isolates exhibited the genetic markers cblA and BCESM, assessed by polymerase chain reaction. In contrast, the profile of enzymatic activity, assessed by phenotypic methods, differed among the BCC species: protease activity was detected only in B. cenocepacia and B. ambifaria isolates, whereas only B. vietnamiensis isolates produced hemolysin. Although the phospholipase C activity was similar among the different species, the level of lipase activity produced by B. multivorans was higher than in the other species. We speculate that the differential characteristics of exoenzyme production may account for the differences in the pathogenic potentials of each BCC species.
Carvalho
Ana Paula D'Allicourt
AP
Departamento de Microbiologia e Imunologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
Ventura
Grasiella Maria Carvalho
GM
Pereira
Carolina Borges
CB
Leão
Robson Souza
RS
Folescu
Tânia Wrobel
TW
Higa
Laurinda
L
Teixeira
Lucia Martins
LM
Plotkowski
Maria Cristina Maciel
MC
Merquior
Vânia Lucia Carreira
VL
Albano
Rodolpho Mattos
RM
Marques
Elizabeth Andrade
EA
D001426:Bacterial Proteins / Q000032:analysis; D015373:Bacterial Typing Techniques; D015415:Biomarkers / Q000032:analysis; D001938:Brazil; D019117:Burkholderia / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D019121:Burkholderia Infections / Q000382:microbiology*; D016956:Burkholderia cepacia / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D003550:Cystic Fibrosis / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D004798:Enzymes / Q000032:analysis; D006801:Humans; D008171:Lung Diseases / Q000382:microbiology*; D011110:Polymorphism, Genetic; D014774:Virulence / Q000235:genetics
D001426:Bacterial Proteins; D015415:Biomarkers; D004798:Enzymes