TABLE 4.
Phenotypic characteristics of sequential isolate pairs of Candida spp. derived from oral rinse samples
| Species and isolate no. | API 20C AUX profile | Resistotypea
|
Overall difference (%)b | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| ACR | BA | CET | CHX | CuSO4 | NaCl | NaIO4 | Na2SeO3 | Mac | |||
| C. albicansc | |||||||||||
| L1d | 2576174 | (+) | (+) | (+) | + | + | + | + | + | + | 9 |
| L1′ | 2576174 | − | − | − | + | − | + | + | + | + | |
| L2 | 2576174 | − | − | − | (+) | − | + | − | + | + | 9 |
| L2′ | 2576174 | (+) | − | − | + | − | + | − | − | + | |
| L3 | 2576174 | + | − | − | (+) | − | + | − | + | + | 18 |
| L3′ | 2576174 | + | − | − | (+) | + | − | − | + | + | |
| L4 | 2576174 | (+) | − | − | (+) | − | − | + | − | + | 36 |
| L4′ | 2576174 | + | + | + | − | − | + | + | + | + | |
| L5 | 2576174 | − | − | − | − | − | + | − | (+) | − | 18 |
| L5′ | 2576174 | + | − | − | − | − | − | − | − | (+) | |
| L6 | 2564174 | + | (+) | + | + | − | − | − | + | + | 18 |
| L6′ | 2564174 | + | (+) | − | − | − | − | − | + | + | |
| L7 | 2576174 | + | − | − | + | − | − | − | + | + | 9 |
| L7′ | 2576174 | + | − | (+) | − | − | − | − | + | + | |
| L8e | 2576174 | + | − | − | + | − | (+) | − | + | + | 36 |
| L8′ | 2576174 | − | − | + | − | − | − | − | + | − | |
| L9e | 2576174 | − | + | + | − | − | − | − | + | − | 36 |
| L9′ | 2576174 | − | − | − | + | − | − | − | + | + | |
| L10e | 2566174 | + | − | − | − | − | − | + | + | + | 45 |
| L10′ | 2566174 | − | + | − | + | + | − | (+) | − | + | |
| C. tropicalis | |||||||||||
| L11f | 2556171 | − | + | − | − | − | − | (+) | − | + | 30 |
| L11′ | 2556171 | − | + | − | + | + | − | + | + | + | |
| L12e | 2556371 | − | (+) | − | − | − | + | + | + | + | 10 |
| L12′ | 2556371 | + | + | − | − | − | + | + | + | + | |
ACR, acrylamide (12 mg/ml); BA, boric acid (2.5 mg/ml); CET, cetrimide (0.2 mg/ml); CHX, chlorhexidine (0.25% [vol/vol]); CuSO4, copper (II) sulphate (2 mg/ml); NaCl, sodium chloride (187.5 mg/ml); NaIO4, sodium periodate (3 mg/ml); Na2SeO3, sodium selenite (7.5 mg/ml); Mac, MacConkey agar; +, resistant; (+), intermediately resistant; −, susceptible.
Overall difference determined by the API 20C AUX profile and/or the API ZYM profile (C. albicans only) plus the nine resistotyping profiles. For C. albicans, 11 tests were done; for C. tropicalis, 10 tests were done. All tests were assigned the same weighting, with (+) considered indifferent. Considering the difference between isolate pairs in relation to antifungal therapy versus the overall difference in phenotypic characteristics (dichotomized as follows: an overall difference of <30% was considered low and an overall difference of ≥30% was considered high), significantly less C. albicans phenotypic change (low group) was observed in isolate pairs from subjects who did not undergo antifungal therapy (Fisher exact test, P = 0.033)
All C. albicans species were of API ZYM biotype J (21). The API 20C AUX secondary biotype for isolate pair L6-L6′ was 11 (46), for isolate pair L10-L10′ was 24 (21) and for all the rest was 1 (46).
A designation consisting of a letter and a number indicates that the isolate was isolated before antifungal and/or hygienic therapy; a designation consisting of the same letter and number, as well as a prime symbol, indicates that the isolate was isolated after antifungal and/or hygienic therapy.
Isolate pairs recovered from subjects who underwent antifungal therapy.
Isolate collected from a denture wearer.