Skip to main content

Table 2 Performance of mPCR and concordance of phenotypical and genotypical antimicrobial susceptibility of all tested isolates

From: Value of multiplex PCR for detection of antimicrobial resistance in samples retrieved from patients with orthopaedic infections

Pathogen/AntimicrobialGene targetSusceptible by mPCR [no.]Resistant by mPCR [no.]Susceptible by culture [no.]Resistant by culture [no.]Sensitivity [%] (95% CI)Specificity [%] (95% CI)Concordance [%] (95% CI)NPV [%] (95% CI)PPV [%] (95% CI)
Coagulase-negative staphylococci
 Oxacillin (n = 30)mecA, mecC201072344 (26–63)100 (59–100)57 (39–74)35 (14–56)100 (100)
 Aminoglycosides (n = 32)aac(6′)/aph(2″)239131942 (23–64)92 (64–100)63 (46–79)52 (32–73)89 (68–100)
 Macrolides/lincos-amides (n = 33)ermA, ermC1914141958 (36–77)79 (51–93)67 (51–83)58 (36–80)79 (57–100)
 Rifampin (n = 28)rpoB2802260 (0–46)100 (85–100)78 (59–91)79 (79)
Staphylococcus aureus
 Oxacillin (n = 16)mecA, mecC142142100 (29–100)100 (74–100)100 (100)100 (100)100 (100)
 Aminoglycosides (n = 16)aac(6′)/aph(2″)1601510 (0–98)100 (78–100)94 (94)94 (70–100)
 Macrolides/lincos-amides (n = 16)ermA, ermC14212450 (15–85)100 (71–100)88 (71–100)86 (67–100)100 (100)
 Rifampin (n = 15)rpoB132141100 (17–100)93 (66–100)93 (81–100)100 (100)50 (0–100)
Enterococcus spp.
 Aminoglycosides (high-level) (n = 7)aac(6′)/aph(2″)614333 (6–80)100 (45–100)71 (38–100)67 (29–100)100 (100)
 Vancomycin (n = 10)vanA, vanB100100100 (69–100)100 (69–100)100 (100)
Enterobacteriaceae
 Aminoglycosides (n = 14)aacA410414071 (42–92)71 (42–92)1000
 Carbapenems (n = 14)blavim, blaimp, blakpc, blandm, blaoxa-23, blaoxa-24, blaoxa-48, blaoxa-58140140100 (77–100)100 (77–100)100
 Third-generation cephalosporins (n = 14)ctx-M140140100 (77–100)100 (77–100)100
 Fluoroquinolonesa (n = 9)gyrA83, gyrA875463100 (38–100)83 (42–98)89 (68–100)100 (100)75 (33-100)
Streptococcus agalactiae
 Macrolides/lincosamides (n = 10)ermA, ermC100820 (0–84)100 (63–100)80 (44–97)80 (80)
Cutibacterium spp
 Rifampin (n = 6)rpoB6060100 (54–100)100 (54–100)100 (100)
 Total, median (range)     46 (36–56)95 (90–97)80 (75–84)80 (74–85)79 (68–91)
  1. Note: Sensitivity and specificity of mPCR considering culture testing (VITEK) as gold standard
  2. aOnly E. coli isolates were tested for fluoroquinolone resistance by mPCR