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.
Subject(s)
Orthopedic Procedures , Orthopedics , Staphylococcal Infections , Coagulase , Genotype , Humans , Prospective Studies , Staphylococcal Infections/diagnosis , Staphylococcus/geneticsABSTRACT
Las anastomosis carótido-vertebro basilares son anomalías que representan patrones circulatorios embrionarios persistentes. Los canales entre la aorta embrionaria (que acaba dando lugar a la arteria carótida) y las arterias neurales longitudinales pares (que dan lugar a las arterias basilar y vertebral) son las llamadas anastomosis del sistema carótido-vertebrobasilar. Hasta el momento, se reconocen cuatro anastomosis principales que son la arteria ótica, la arteria hipoglosa primitiva, la arteria trigeminal primitiva y la intersegmentaria proatlantoidea. Cuando estas anastomosis no se reabsorben, persisten en la edad adulta. En esta breve revisión nos centraremos en la arteria trigeminal primitiva ya que, por frecuencia, es la más importante. Asimismo, se revisan todos los casos con repercusión clínica informados en la literatura desde 1991 hasta la fecha...
