Table 1.
Characterization of staphylococcal isolates associated with conjunctivitis: ica gene detection profiles, phenotypic biofilm production, and antibiotic resistance results
| No | Isolate no | Antibiotic resistance profile | Mean absorbance value (OD570)/ biofilm production capability** | ica genes detected by PCR |
|---|---|---|---|---|
| Staphylococcus epidermidis isolates | ||||
| 1 | 2 SE | Fully susceptible | 0.135/weak | – |
| 2 | 7 SE | TE | 0.143/weak | – |
| 3 | 12 SE | Fully susceptible | 0.149/weak | – |
| 4 | 13 SE | SXT, OFX | 0.150/weak | icaA |
| 5 | 17 SE | MLSB | 0.142/weak | – |
| 6 | 18 SE | Fully susceptible | 0.144/weak | |
| 7 | 19 SE | Fully susceptible | 0.148/weak | |
| 8 | 20 SE | MLSB | 0.173/weak | – |
| 9 | 21 SE* | FOX, TE, C | 0.599/strong | icaAD, |
| ica operon | ||||
| 10 | 23 SE* | FOX, MLSB, TE, NOR, CIP, OFX, MXF, SXT | 0.187/weak | icaAD |
| 11 | 28 SE* | FOX, MLSB, NOR, CIP, OFX, LVX, MFX, GM, AN, N | 0.175/weak | icaAD |
| 12 | 31 SE* | FOX, MLSB, NOR, CIP, OFX, LVX, MFX, GM, C | 0.161/weak | icaAD, |
| ica operon | ||||
| 13 | 31 I SE | FOX, MLSB | 0.142/weak | – |
| 14 | 31 III SE | MLSB | 0.645/strong | icaAD, |
| ica operon | ||||
| 15 | 31VII SE | MLSB | 0.252/strong | – |
| 16 | 31VIII SE | FOX | 0.166/weak | – |
| 17 | A SE | MLSB | 0.149/weak | – |
| 18 | 33 SE | Fully susceptible | 0.135/weak | – |
| 19 | 34 SE* | MLSB, TE, CIP, OFX, LFX, GM, AN, N, SXT | 0.339/strong | – |
| 20 | 35 SE* | MLSB, TE, OFX, SXT | 0.552/strong | icaAD, |
| ica operon | ||||
| 21 | 36 SE* | FOX, MLSB, SXT | 0.136/weak | – |
| 22 | 39 SE | TE | 0.151/weak | – |
| 23 | 42 SE* | FOX, MLSB, TE, NOR, CIP, OFX, LVX, MFX, GM, N, SXT | 0.184/weak | – |
| 24 | 45 SE | FOX, N | 0.193/weak | – |
| 25 | 46 SE | MLSB | 0.129/weak | – |
| 26 | 49 SE | MLSB | 0.128/weak | – |
| Staphylococcus aureus isolates | ||||
| 1 | 1SA | Fully susceptible | 0.169/weak | ica D |
| 2 | 3 SA | Fully susceptible | 0.179/weak | ica D |
| 3 | 4 SA | TE | 0.162/weak | – |
| 4 | 5 SA | Fully susceptible | 0.348/strong | – |
| 5 | 6 SA | Fully susceptible | 0.157/weak | – |
| 6 | 8 SA | TE, GM, N | 0.189/weak | icaD |
| 7 | 9 SA | Fully susceptible | 0.162/weak | – |
| 8 | 10 SA | Fully susceptible | 0.153/weak | – |
| 9 | 11 SA | Fully susceptible | 0.337/strong | ica D |
| 10 | 15 SA | Fully susceptible | 0.273/strong | – |
| 11 | 16 SA | Fully susceptible | 0.206/weak | – |
| 12 | 22 SA | Fully susceptible | 0.200/weak | ica D |
| 13 | 24 SA | Fully susceptible | 0.205/weak | ica D |
| 14 | 25 SA* | FOX, MLSB, NOR, CIP, C | 0.212/weak | IcaD |
| 15 | 30 SA* | FOX, MLSB, C | 0.185/weak | IcaD |
| 16 | 32 SA | Fully susceptible | 0.264/strong | – |
| 17 | 37 SA | Fully susceptible | 0.204/weak | – |
| 18 | 40 SA | Fully susceptible | 0.158/weak | ica AD |
| 19 | 47 SA | TE | 0.468/strong | – |
| 20 | 48 SA | MLSB | 0.138/weak | – |
| 21 | 50 SA* | FOX, MLSB, GM, AN, N | 0.191/weak | icaD |
| 22 | 53 SA | FOX, MLSB | 0.186/weak | icaD |
| 23 | 54 SA* | FOX, MLSB, NOR, CIP, OFX, LVX, MFX, AN, N | 0.383/strong | – |
| 24 | 56 SA* | FOX, MLSB, NOR, CIP, OFX, LVX, MFX, AN, N | 0.328/strong | – |
| 25 | 57 SA* | FOX, MLSB, NOR, CIP, OFX, LVX, MFX, AN, N | 0.203/weak | – |
| 26 | 58 SA | Fully susceptible | 0.153/weak | – |
*Multidrug resistance (MDR); **OD ≤ 0.120 – non-adherent; OD > 240 – strongly adherent; OD > 120 ≤ 0.240 – weakly adherent; SA—Staphylococcus aureus, SE—Staphylococcus epidermidis, MLSB—cross-resistance to macrolides, lincosamides, and streptogramin B, cefoxitin; detection of methicillin resistance (FOX), erythromycin (E), clindamycin (CC), tetracycline (TE), norfloxacin (NOR), ciprofloxacin (CIP), ofloxacin (OFX), levofloxacin (LVX), moxifloxacin (MXF), gentamicin (GM), amikacin (AN), neomycin (N), chloramphenicol (C), co-trimoxazole (TMP/SXT)