Abstract
Clinical isolates Enterococcus gallinarum AIB39 and E. gallinarum GS1 were studied to establish whether the expression of vanC-1-mediated resistance may be inducible or constitutive. By growth curve analysis, strain AIB39 exhibited the same lag period (i.e., 1 to 1.5 h) whether it was subcultured to unsupplemented brain heart infusion broth or broth containing 6 micrograms of vancomycin per ml, a growth pattern typical of constitutively expressed resistance. Use of high-performance liquid chromatography (HPLC) to separate peptidoglycan precursor extracts substantiated this finding because the serine-terminating pentapeptide precursor UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ser was produced in the presence and absence of vancomycin, whereas no UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala was detected. In contrast, results with strain GS1 were consistent with inducible expression. GS1 demonstrated a lag time that was 3 to 4 h longer when it was subcultured to vancomycin-containing broth than when it was subcultured in unsupplemented broth. HPLC analysis showed that in the absence of vancomycin only UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala was detected, but in the presence of drug only UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala was found. Inducible expression of vanC-1-mediated resistance in E. gallinarum is consistent with recent findings suggesting the presence of at least two ligases in this species. Although vanC-1 may be intrinsic to E. gallinarum, our findings raise doubt regarding the natural mechanism of this gene's expression.
Full Text
The Full Text of this article is available as a PDF (212.3 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Arthur M., Courvalin P. Genetics and mechanisms of glycopeptide resistance in enterococci. Antimicrob Agents Chemother. 1993 Aug;37(8):1563–1571. doi: 10.1128/aac.37.8.1563. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Arthur M., Depardieu F., Snaith H. A., Reynolds P. E., Courvalin P. Contribution of VanY D,D-carboxypeptidase to glycopeptide resistance in Enterococcus faecalis by hydrolysis of peptidoglycan precursors. Antimicrob Agents Chemother. 1994 Sep;38(9):1899–1903. doi: 10.1128/aac.38.9.1899. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Billot-Klein D., Gutmann L., Sablé S., Guittet E., van Heijenoort J. Modification of peptidoglycan precursors is a common feature of the low-level vancomycin-resistant VANB-type Enterococcus D366 and of the naturally glycopeptide-resistant species Lactobacillus casei, Pediococcus pentosaceus, Leuconostoc mesenteroides, and Enterococcus gallinarum. J Bacteriol. 1994 Apr;176(8):2398–2405. doi: 10.1128/jb.176.8.2398-2405.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bugg T. D., Wright G. D., Dutka-Malen S., Arthur M., Courvalin P., Walsh C. T. Molecular basis for vancomycin resistance in Enterococcus faecium BM4147: biosynthesis of a depsipeptide peptidoglycan precursor by vancomycin resistance proteins VanH and VanA. Biochemistry. 1991 Oct 29;30(43):10408–10415. doi: 10.1021/bi00107a007. [DOI] [PubMed] [Google Scholar]
- Clewell D. B., Tomich P. K., Gawron-Burke M. C., Franke A. E., Yagi Y., An F. Y. Mapping of Streptococcus faecalis plasmids pAD1 and pAD2 and studies relating to transposition of Tn917. J Bacteriol. 1982 Dec;152(3):1220–1230. doi: 10.1128/jb.152.3.1220-1230.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dutka-Malen S., Blaimont B., Wauters G., Courvalin P. Emergence of high-level resistance to glycopeptides in Enterococcus gallinarum and Enterococcus casseliflavus. Antimicrob Agents Chemother. 1994 Jul;38(7):1675–1677. doi: 10.1128/aac.38.7.1675. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dutka-Malen S., Evers S., Courvalin P. Detection of glycopeptide resistance genotypes and identification to the species level of clinically relevant enterococci by PCR. J Clin Microbiol. 1995 Jan;33(1):24–27. doi: 10.1128/jcm.33.1.24-27.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dutka-Malen S., Molinas C., Arthur M., Courvalin P. Sequence of the vanC gene of Enterococcus gallinarum BM4174 encoding a D-alanine:D-alanine ligase-related protein necessary for vancomycin resistance. Gene. 1992 Mar 1;112(1):53–58. doi: 10.1016/0378-1119(92)90302-6. [DOI] [PubMed] [Google Scholar]
- Dutka-Malen S., Molinas C., Arthur M., Courvalin P. The VANA glycopeptide resistance protein is related to D-alanyl-D-alanine ligase cell wall biosynthesis enzymes. Mol Gen Genet. 1990 Dec;224(3):364–372. doi: 10.1007/BF00262430. [DOI] [PubMed] [Google Scholar]
- Evers S., Reynolds P. E., Courvalin P. Sequence of the vanB and ddl genes encoding D-alanine:D-lactate and D-alanine:D-alanine ligases in vancomycin-resistant Enterococcus faecalis V583. Gene. 1994 Mar 11;140(1):97–102. doi: 10.1016/0378-1119(94)90737-4. [DOI] [PubMed] [Google Scholar]
- Facklam R. R., Collins M. D. Identification of Enterococcus species isolated from human infections by a conventional test scheme. J Clin Microbiol. 1989 Apr;27(4):731–734. doi: 10.1128/jcm.27.4.731-734.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Handwerger S., Pucci M. J., Kolokathis A. Vancomycin resistance is encoded on a pheromone response plasmid in Enterococcus faecium 228. Antimicrob Agents Chemother. 1990 Feb;34(2):358–360. doi: 10.1128/aac.34.2.358. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Handwerger S., Pucci M. J., Volk K. J., Liu J., Lee M. S. The cytoplasmic peptidoglycan precursor of vancomycin-resistant Enterococcus faecalis terminates in lactate. J Bacteriol. 1992 Sep;174(18):5982–5984. doi: 10.1128/jb.174.18.5982-5984.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Handwerger S., Pucci M. J., Volk K. J., Liu J., Lee M. S. Vancomycin-resistant Leuconostoc mesenteroides and Lactobacillus casei synthesize cytoplasmic peptidoglycan precursors that terminate in lactate. J Bacteriol. 1994 Jan;176(1):260–264. doi: 10.1128/jb.176.1.260-264.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hayden M. K., Trenholme G. M., Schultz J. E., Sahm D. F. In vivo development of teicoplanin resistance in a VanB Enterococcus faecium isolate. J Infect Dis. 1993 May;167(5):1224–1227. doi: 10.1093/infdis/167.5.1224. [DOI] [PubMed] [Google Scholar]
- Jacob A. E., Hobbs S. J. Conjugal transfer of plasmid-borne multiple antibiotic resistance in Streptococcus faecalis var. zymogenes. J Bacteriol. 1974 Feb;117(2):360–372. doi: 10.1128/jb.117.2.360-372.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leclercq R., Dutka-Malen S., Duval J., Courvalin P. Vancomycin resistance gene vanC is specific to Enterococcus gallinarum. Antimicrob Agents Chemother. 1992 Sep;36(9):2005–2008. doi: 10.1128/aac.36.9.2005. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Navarro F., Courvalin P. Analysis of genes encoding D-alanine-D-alanine ligase-related enzymes in Enterococcus casseliflavus and Enterococcus flavescens. Antimicrob Agents Chemother. 1994 Aug;38(8):1788–1793. doi: 10.1128/aac.38.8.1788. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reynolds P. E., Depardieu F., Dutka-Malen S., Arthur M., Courvalin P. Glycopeptide resistance mediated by enterococcal transposon Tn1546 requires production of VanX for hydrolysis of D-alanyl-D-alanine. Mol Microbiol. 1994 Sep;13(6):1065–1070. doi: 10.1111/j.1365-2958.1994.tb00497.x. [DOI] [PubMed] [Google Scholar]
- Reynolds P. E., Snaith H. A., Maguire A. J., Dutka-Malen S., Courvalin P. Analysis of peptidoglycan precursors in vancomycin-resistant Enterococcus gallinarum BM4174. Biochem J. 1994 Jul 1;301(Pt 1):5–8. doi: 10.1042/bj3010005. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sahm D. F., Kissinger J., Gilmore M. S., Murray P. R., Mulder R., Solliday J., Clarke B. In vitro susceptibility studies of vancomycin-resistant Enterococcus faecalis. Antimicrob Agents Chemother. 1989 Sep;33(9):1588–1591. doi: 10.1128/aac.33.9.1588. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sahm D. F., Olsen L. In vitro detection of enterococcal vancomycin resistance. Antimicrob Agents Chemother. 1990 Sep;34(9):1846–1848. doi: 10.1128/aac.34.9.1846. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Swenson J. M., Clark N. C., Ferraro M. J., Sahm D. F., Doern G., Pfaller M. A., Reller L. B., Weinstein M. P., Zabransky R. J., Tenover F. C. Development of a standardized screening method for detection of vancomycin-resistant enterococci. J Clin Microbiol. 1994 Jul;32(7):1700–1704. doi: 10.1128/jcm.32.7.1700-1704.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vincent S., Knight R. G., Green M., Sahm D. F., Shlaes D. M. Vancomycin susceptibility and identification of motile enterococci. J Clin Microbiol. 1991 Oct;29(10):2335–2337. doi: 10.1128/jcm.29.10.2335-2337.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vincent S., Minkler P., Bincziewski B., Etter L., Shlaes D. M. Vancomycin resistance in Enterococcus gallinarum. Antimicrob Agents Chemother. 1992 Jul;36(7):1392–1399. doi: 10.1128/aac.36.7.1392. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williamson R., Al-Obeid S., Shlaes J. H., Goldstein F. W., Shlaes D. M. Inducible resistance to vancomycin in Enterococcus faecium D366. J Infect Dis. 1989 Jun;159(6):1095–1104. doi: 10.1093/infdis/159.6.1095. [DOI] [PubMed] [Google Scholar]
- Zarlenga L. J., Gilmore M. S., Sahm D. F. Effects of amino acids on expression of enterococcal vancomycin resistance. Antimicrob Agents Chemother. 1992 Apr;36(4):902–905. doi: 10.1128/aac.36.4.902. [DOI] [PMC free article] [PubMed] [Google Scholar]