title: Evaluation of the time period for which real-time polymerase chain reaction detects dead bacteria.
abstract: Real-time polymerase chain reaction (PCR) is currently widely used for the diagnosis of infections. We evaluated the time after treatment during which real-time PCR can detect dead bacteria. The presence of bacterial DNA was identified by real-time PCR through methicillin-resistant Staphylococcus (MRS)-PCR and universal PCR. Methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, and Escherichia coli were each killed with alcohol, antibiotics, or heat treatment in vitro. The detection periods of MRS-PCR for MRSA treated by alcohol, vancomycin, linezolid, and heat were found to be less than 16, 8, 12, and 8 weeks, respectively. The detection period of universal PCR for S. epidermidis treated by alcohol, cefazolin, and heat was less than 20, 20, and 4 weeks, whereas that for E. coli was 8, 20, and 4 weeks, respectively. The presence of detectable bacterial DNA in infected arthroplasty patients before and after successful treatment was also assessed by MRS- and universal PCR. MRS-PCR was positive in 6 patients before treatment and all became negative after a mean interval of 20.8 weeks (95% confidential interval, 13.2 to 33.7) after treatment. Universal PCR detected remnant bacterial DNA in 4 patients at a mean of 15.2 weeks (95% CI, 12.4 to 18.0) after treatment and was negative in 7 patients at a mean of 17.3 weeks (95% CI, 10.6 to 24.0) after treatment. Our studies revealed that real-time PCR detects dead bacteria for several weeks, but this capability decreases with time and is likely lost by 20 weeks after treatment.
authors: Hyonmin
authors: H
authors: Choe
authors: Yutaka
authors: Y
authors: Inaba
authors: Naomi
authors: N
authors: Kobayashi
authors: Yushi
authors: Y
authors: Miyamae
authors: Hiroyuki
authors: H
authors: Ike
authors: Hiroshi
authors: H
authors: Fujimaki
authors: Taro
authors: T
authors: Tezuka
authors: Yasuhide
authors: Y
authors: Hirata
authors: Tomoyuki
authors: T
authors: Saito
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D050296:Microbial Viability; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D017931:DNA Primers; D004269:DNA, Bacterial