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PLoS One

Title:		Pherotype influences biofilm growth and recombination in Streptococcus pneumoniae
Author(s):		Carrolo M; Pinto FR; Melo-Cristino J; Ramirez M;
Address:		"Instituto de Microbiologia, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal. Centro de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, Lisboa, Portugal"
Journal Title:		PLoS One
Year:		2014
Volume:		20140319
Issue:		3
Page Number:		e92138 -
DOI:		10.1371/journal.pone.0092138
ISSN/ISBN:		1932-6203 (Electronic) 1932-6203 (Linking)
Abstract:		"In Streptococcus pneumoniae the competence-stimulating peptide (CSP), encoded by the comC gene, controls competence development and influences biofilm growth. We explored the influence of pherotype, defined by the two major comC allelic variants (comC1 and comC2), on biofilm development and recombination efficiency. Among isolates recovered from human infections those presenting comC1 show a higher capacity to form in vitro biofilms. The influence of pherotype on biofilm growth was confirmed by experiments with isogenic strains differing in their comC alleles. Biofilm architecture evaluated by confocal laser scanning microscopy showed that strains carrying comC1 form biofilms that are denser and thicker than those carrying the comC2 allele. Isogenic strains carrying the comC1 allele yielded more transformants than those carrying the comC2 allele in both planktonic and biofilm growth. Transformation assays with comC knockout strains show that ComD1 needs lower doses of the signaling peptide to reach the same biological outcomes. In contrast to mixed planktonic growth, within mixed biofilms inter-pherotype genetic exchange is less frequent than that occurring between bacteria of the same pherotype. Since biofilms are a major bacterial lifestyle, these observations may explain the genetic differentiation between populations with different pherotypes reported previously. Considering that biofilms have been associated with colonization our results suggest that strains carrying the comC1 allele may be more transmissible and more efficient at persisting in carriage. Both effects may help explain the higher prevalence of the comC1 allele in the pneumococcal population"
Keywords:		"Bacterial Proteins/metabolism Biofilms/*growth & development Linear Models Mutant Proteins/metabolism Pheromones/*metabolism Plankton/growth & development Recombination, Genetic/*genetics Streptococcus pneumoniae/*genetics/*physiology Transformation, Bact;"
Notes:		"MedlineCarrolo, Margarida Pinto, Francisco Rodrigues Melo-Cristino, Jose Ramirez, Mario eng Research Support, Non-U.S. Gov't 2014/03/22 PLoS One. 2014 Mar 19; 9(3):e92138. doi: 10.1371/journal.pone.0092138. eCollection 2014"