A rapid molecular assay for the detection of antibiotic resistance determinants in causal agents of infective endocarditis.
OBJECTIVE
To develop and employ a PCR amplification system, directly from clinical specimens, for the rapid molecular detection of common antimicrobial resistance genes for streptococci, staphylococci and enterococci organisms causing infective endocarditis (IE).


RESULTS
Eleven antibiotic resistance genes were targeted by PCR along with four identification-related loci. Blood culture and heart valve material from staphylococcal endocarditis patients were directly examined for methicillin resistance. PCR conditions were optimized for the following antibiotic resistance loci: staphylococci (mecA, aacA-aphD), streptococci (PBP 1A, PBP 2B, gyrB, parE) and enterococci (vanA, vanB, vanC-1, vanC-2, aacA-aphD, aphA3). The presence of methicillin resistance was confirmed in one of the eight IE patients examined.


CONCLUSIONS
This study presents a PCR amplification system for the detection of antibiotic resistance genes. Detection of such genes may indicate susceptibility of the causal agents of IE to commonly prescribed antimicrobial agents.


CONCLUSIONS
Rapid detection of antibiotic resistant organisms may reduce the use of inappropriate antibiotic agents or enable the use of the most appropriate combinations of antibiotics, other than those that would normally be prescribed empirically for IE. Such a method may be particularly valuable in cases of culture-negative endocarditis. Detection of antibiotic resistance genes by molecular-based techniques, namely PCR, will allow more directed antibiotic therapy and may also provide opportunities for earlier identification of resistant organisms.
Moore
J E
JE
Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Belfast, Northern Ireland, UK. jemoore@niphl.dnet.co.uk
Millar
B C
BC
Yongmin
X
X
Woodford
N
N
Vincent
S
S
Goldsmith
C E
CE
McClurg
R B
RB
Crowe
M
M
Hone
R
R
Murphy
P G
PG
D004352:Drug Resistance, Microbial / Q000235:genetics*; D004697:Endocarditis, Bacterial / Q000097:blood / Q000382:microbiology*; D016983:Enterococcus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D005798:Genes, Bacterial; D006095:Gram-Positive Cocci / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006351:Heart Valves / Q000382:microbiology; D006801:Humans; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance / Q000235:genetics; D010406:Penicillins / Q000494:pharmacology; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D013210:Staphylococcus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D013291:Streptococcus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification
D010406:Penicillins; D012336:RNA, Ribosomal, 16S; D008712:Methicillin