Higher accuracy of genotypic identification compared to phenotyping in the diagnosis of coagulase-negative staphylococcus infection in orthopedic surgery.
Infect Dis (Lond)
; 52(12): 883-890, 2020.
Article
em En
| MEDLINE
| ID: mdl-32735157
ABSTRACT
PURPOSE:
To determine whether Repetitive Extragenic Palindromic PCR (rep-PCR) genotyping can improve the diagnosis of coagulase-negative staphylococcal (CoNS) orthopaedic infections in comparison to phenotyping.METHODS:
Prospective study comparing the results of phenotypic/genotypic (rep-PCR) testing in patients with suspected CoNS infection. Each strain was analysed using both methods. Strains identified as identical in ≥2 samples were considered as pathogenic.RESULTS:
255 CoNS strains from 52 surgical episodes were included. Infection was diagnosed by phenotyping in 38(73%) cases and by genotyping in 40(77%). The Kappa index was 0.59. Sensitivity, Specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) for phenotyping (vs. rep-PCR) were 88%, 75%, 92%, and 64%. 5/14(36%) of cases not considered as true infections by phenotyping were diagnosed as infections with genotyping. In a subgroup of 203 strains from 41 surgical procedures with orthopaedic implants, the kappa index was 0.68. Sensitivity, Specificity, PPV, and NPV for phenotyping were 93%, 73%, 90% and 80%. Again, 2/10 episodes in which CoNS were considered non-infective by phenotyping were diagnosed as infected by genotyping.CONCLUSIONS:
Rep-PCR genotyping can identify identical CoNS strains that differ in their phenotype and should be used as a complementary technique. One-third of infected cases may be misdiagnosed without genotypic analysis.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ortopedia
/
Infecções Estafilocócicas
/
Procedimentos Ortopédicos
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article