TY - JOUR
T1 - The important role of nontypable Streptococcus pneumoniae international clones in acute conjunctivitis
AU - Porat, Nurith
AU - Greenberg, David
AU - Givon-Lavi, Moga
AU - Shuval, Dror S.
AU - Trefler, Ronit
AU - Segev, Orit
AU - Hanage, William P.
AU - Dagan, Ron
PY - 2006/9/1
Y1 - 2006/9/1
N2 - Background. In a recent epidemiological study in southern Israel, nontypable Streptococcus pneumoniae isolates were found to be highly associated with sporadic cases of acute conjunctivitis (AC). The purpose of the present study was to evaluate the relative importance in causing AC of the absence of capsule versus genotype properties. Methods. DNA typing by pulsed-field gel electrophoresis (PFGE) was performed on 148 nontypable organisms isolated from 3 sites: nasopharynx of healthy children, middle-ear fluid, and conjunctiva. Results. Analysis of the PFGE patterns revealed the presence of 6 clusters; 2 clusters that included 44% of the isolates (65/148) were associated with AC, and the remaining 4 were frequently isolated from the nasopharynx. Multilocus sequence typing, performed on representative isolates of the 2 major clusters, confirmed that the organisms were pneumococci; one is a single-locus variant of sequence type (ST) 448, and the other is related to ST344. Both types appear to be members of pneumococcal lineages that have lost capsular loci. The nontypable isolates showed high rates of resistance to antimicrobial agents. Conclusions. Our data suggest that the absence of the capsule-along with other, yet-unidentified genetic characteristics-provide S. pneumoniae with a selective virulence advantage in conjunctivitis.
AB - Background. In a recent epidemiological study in southern Israel, nontypable Streptococcus pneumoniae isolates were found to be highly associated with sporadic cases of acute conjunctivitis (AC). The purpose of the present study was to evaluate the relative importance in causing AC of the absence of capsule versus genotype properties. Methods. DNA typing by pulsed-field gel electrophoresis (PFGE) was performed on 148 nontypable organisms isolated from 3 sites: nasopharynx of healthy children, middle-ear fluid, and conjunctiva. Results. Analysis of the PFGE patterns revealed the presence of 6 clusters; 2 clusters that included 44% of the isolates (65/148) were associated with AC, and the remaining 4 were frequently isolated from the nasopharynx. Multilocus sequence typing, performed on representative isolates of the 2 major clusters, confirmed that the organisms were pneumococci; one is a single-locus variant of sequence type (ST) 448, and the other is related to ST344. Both types appear to be members of pneumococcal lineages that have lost capsular loci. The nontypable isolates showed high rates of resistance to antimicrobial agents. Conclusions. Our data suggest that the absence of the capsule-along with other, yet-unidentified genetic characteristics-provide S. pneumoniae with a selective virulence advantage in conjunctivitis.
UR - http://www.scopus.com/inward/record.url?scp=33748034744&partnerID=8YFLogxK
U2 - 10.1086/506453
DO - 10.1086/506453
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C2 - 16897669
AN - SCOPUS:33748034744
SN - 0022-1899
VL - 194
SP - 689
EP - 696
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
IS - 5
ER -