NALLAPAREDDY SR, HUANG W, WEINSTOCK GM, MURRAY BE; Interscience Conference on Antimicrobial Agents and Chemotherapy (43rd: 2003: Chicago, Ill.).

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2003 Sep 14-17; 43: abstract no. C2-2165.

University of Texas Med. School, Houston, TX.

BACKGROUND: Identification of widespread clones may have important implications for pathogenesis and infection control. Based on preliminary multilocus sequence typing (MLST) with 4 genes suggesting an unexpected relatedness of Efs of temporally and geographically diverse origins, we used 9 gene MLST which led us to recognize that an outbreak Efs strain and Efs expressing two resistance phenotypes unusual for this species, Van[r] and beta-lactamase (Bla), have the same genetic background. METHODS: Intragenic regions of 3 antigen-encoding genes (ace, efaA, and salA) and 6 housekeeping genes (pyrC, aroE, gki, gdh, xpt, and yqiL) from 21 selected Efs isolates were sequenced. Genes differing by 1 nt were considered different alleles and allelic profiles of the 9 loci defined the sequence type (ST). In keeping with definitions for pneumococci and staphylococci, single locus variants (SLV) were considered members of the same clonal complex. RESULTS: MLST identified 15 STs forming 11 clonal complexes with 4 SLVs that corresponded to the PFGE types. The previously PFGE-defined mid-Atlantic (Va., Del., Penn., NC plus Fla. and Tex.) Bla[+] clonal isolates were shown to have an identical ST (ST-6) or to be a SLV (ST-7, varying by 2 of 5287 bp, both in salA). The 1st USA (Missouri) VRE (E. faecalis V583, sequenced by TIGR) and an outbreak Efs (MMH594) from a neighboring state with HLR Gm (gentamicin) resistance differed from ST-6 by 1 nt in efa (ST-14). A Van[s] endocarditis isolate (Bla[-], HLR Gm) also from Missouri differed from ST-14 by 1 nt (pyrC). Analysis of these isolates also showed related PFGE patterns, previously not recognized. CONCLUSION: MLST identified the presence of an unusual circulating clonal cluster within the USA and recognized unexpected relationships, that is, that 2 unusual resistances of E. faecalis, Bla and Van[R], as well as an outbreak strain and an endocarditis isolate (Bla[-], Van[S)], all belong to the same clonal complex.

Publication Types:

• Meeting Abstracts

Keywords:

• Alleles
• Base Sequence
• Cluster Analysis
• Electrophoresis, Gel, Pulsed-Field
• Enterococcus faecalis
• Missouri
• Streptococcus pneumoniae
• beta-Lactamases
• genetics

Other ID:

• GWAIDS0026860

UI: 102266484

From Meeting Abstracts