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Clotrimazole Drug Resistance in Candida glabrata Clinical Isolates Correlates with Increased Expression of the Drug:H(+) Antiporters CgAqr1, CgTpo1_1, CgTpo3, and CgQdr2.

Costa C, Ribeiro J, Miranda IM, Silva-Dias A, Cavalheiro M, Costa-de-Oliveira S, Rodrigues AG, Teixeira MC - Front Microbiol (2016)

Bottom Line: For years, antifungal drug resistance in Candida species has been associated to the expression of ATP-Binding Cassette (ABC) multidrug transporters.The transcript levels of CgAQR1, CgQDR2, CgTPO1_1, and CgTPO3 were found to be significantly up-regulated in resistant isolates when compared to the susceptible ones, with a level of correlation that was found to be similar to that of CgCDR2, an ABC gene known to be involved in the clinical acquisition of resistance.The deletion of CgTPO3 in this isolate was found to lead to decreased resistance to clotrimazole and fluconazole, and increased accumulation of azole drugs, thus suggesting the involvement of this transporter in the manifestation of azole resistance.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, Instituto Superior Técnico, University of LisbonLisboa, Portugal; Institute for Bioengineering and Biosciences, Biological Sciences Research GroupLisboa, Portugal.

ABSTRACT
For years, antifungal drug resistance in Candida species has been associated to the expression of ATP-Binding Cassette (ABC) multidrug transporters. More recently, a few drug efflux pumps from the Drug:H(+) Antiporter (DHA) family have also been shown to play a role in this process, although to date only the Candida albicans Mdr1 transporter has been demonstrated to be relevant in the clinical acquisition of antifungal drug resistance. This work provides evidence to suggest the involvement of the C. glabrata DHA transporters CgAqr1, CgQdr2, CgTpo1_1, and CgTpo3 in the clinical acquisition of clotrimazole drug resistance. A screening for azole drug resistance in 138 C. glabrata clinical isolates, from patients attending two major Hospitals in Portugal, was performed. Based on this screening, 10 clotrimazole susceptible and 10 clotrimazole resistant isolates were selected for further analysis. The transcript levels of CgAQR1, CgQDR2, CgTPO1_1, and CgTPO3 were found to be significantly up-regulated in resistant isolates when compared to the susceptible ones, with a level of correlation that was found to be similar to that of CgCDR2, an ABC gene known to be involved in the clinical acquisition of resistance. As a proof-of-concept experiment, the CgTPO3 gene was deleted in an azole resistant C. glabrata isolate, exhibiting high levels of expression of this gene. The deletion of CgTPO3 in this isolate was found to lead to decreased resistance to clotrimazole and fluconazole, and increased accumulation of azole drugs, thus suggesting the involvement of this transporter in the manifestation of azole resistance.

No MeSH data available.


Related in: MedlinePlus

Correlation between the fluconazole and clotrimazole MIC50 values determined for the collection of 138 Candida glabrata clinical isolates. A trendline obtained by linear regression of the correlation values is also displayed. A significant correlation using a Spearman test (0.27) was found to exist between clotrimazole (CLT) and fluconazole (FLC) datasets.
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Figure 1: Correlation between the fluconazole and clotrimazole MIC50 values determined for the collection of 138 Candida glabrata clinical isolates. A trendline obtained by linear regression of the correlation values is also displayed. A significant correlation using a Spearman test (0.27) was found to exist between clotrimazole (CLT) and fluconazole (FLC) datasets.

Mentions: Susceptibility profiles against the CLT and FLC for all C. glabrata isolates are summarized in Table 2 (see details in Supplementary Table S1). Regarding the MIC50 values, most isolates (93.5%) were found to be susceptible-dose dependent to FLC, while 9 (6.5%) were found to be resistant to FLC. Additionally, most isolates (64.5%) were found to be resistant to CLT. Interestingly, 48 isolates (34.78%) were found to be resistant to CLT and, at the same time, susceptible-dose dependent to FLC. The opposite, however, was not observed for any of the tested strains. In what concerns CLT, 53.3% of the isolates coming from Hospital of Santa Maria (HSM) were found to be resistant, while isolates harvested in CHSJ had a much higher incidence of clotrimazole-resistance (77.8%). Fluconazole-resistant isolates had a higher incidence in HSM (10.7% vs. 1.6%). Interestingly, using a Spearman test (Spearman coefficient: 0.27) a significant correlation was found to exist between the increase in CLT MIC levels and the FLC MIC levels, when considering the full 138 clinical isolates (Figure 1). The level of correlation, however, is relatively low, accounting for a number of isolates exhibiting CLT resistance and very low FLC MIC values, and suggesting that there may be differences in the molecular mechanisms of acquisition of resistance to these related azole drugs.


Clotrimazole Drug Resistance in Candida glabrata Clinical Isolates Correlates with Increased Expression of the Drug:H(+) Antiporters CgAqr1, CgTpo1_1, CgTpo3, and CgQdr2.

Costa C, Ribeiro J, Miranda IM, Silva-Dias A, Cavalheiro M, Costa-de-Oliveira S, Rodrigues AG, Teixeira MC - Front Microbiol (2016)

Correlation between the fluconazole and clotrimazole MIC50 values determined for the collection of 138 Candida glabrata clinical isolates. A trendline obtained by linear regression of the correlation values is also displayed. A significant correlation using a Spearman test (0.27) was found to exist between clotrimazole (CLT) and fluconazole (FLC) datasets.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835504&req=5

Figure 1: Correlation between the fluconazole and clotrimazole MIC50 values determined for the collection of 138 Candida glabrata clinical isolates. A trendline obtained by linear regression of the correlation values is also displayed. A significant correlation using a Spearman test (0.27) was found to exist between clotrimazole (CLT) and fluconazole (FLC) datasets.
Mentions: Susceptibility profiles against the CLT and FLC for all C. glabrata isolates are summarized in Table 2 (see details in Supplementary Table S1). Regarding the MIC50 values, most isolates (93.5%) were found to be susceptible-dose dependent to FLC, while 9 (6.5%) were found to be resistant to FLC. Additionally, most isolates (64.5%) were found to be resistant to CLT. Interestingly, 48 isolates (34.78%) were found to be resistant to CLT and, at the same time, susceptible-dose dependent to FLC. The opposite, however, was not observed for any of the tested strains. In what concerns CLT, 53.3% of the isolates coming from Hospital of Santa Maria (HSM) were found to be resistant, while isolates harvested in CHSJ had a much higher incidence of clotrimazole-resistance (77.8%). Fluconazole-resistant isolates had a higher incidence in HSM (10.7% vs. 1.6%). Interestingly, using a Spearman test (Spearman coefficient: 0.27) a significant correlation was found to exist between the increase in CLT MIC levels and the FLC MIC levels, when considering the full 138 clinical isolates (Figure 1). The level of correlation, however, is relatively low, accounting for a number of isolates exhibiting CLT resistance and very low FLC MIC values, and suggesting that there may be differences in the molecular mechanisms of acquisition of resistance to these related azole drugs.

Bottom Line: For years, antifungal drug resistance in Candida species has been associated to the expression of ATP-Binding Cassette (ABC) multidrug transporters.The transcript levels of CgAQR1, CgQDR2, CgTPO1_1, and CgTPO3 were found to be significantly up-regulated in resistant isolates when compared to the susceptible ones, with a level of correlation that was found to be similar to that of CgCDR2, an ABC gene known to be involved in the clinical acquisition of resistance.The deletion of CgTPO3 in this isolate was found to lead to decreased resistance to clotrimazole and fluconazole, and increased accumulation of azole drugs, thus suggesting the involvement of this transporter in the manifestation of azole resistance.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, Instituto Superior Técnico, University of LisbonLisboa, Portugal; Institute for Bioengineering and Biosciences, Biological Sciences Research GroupLisboa, Portugal.

ABSTRACT
For years, antifungal drug resistance in Candida species has been associated to the expression of ATP-Binding Cassette (ABC) multidrug transporters. More recently, a few drug efflux pumps from the Drug:H(+) Antiporter (DHA) family have also been shown to play a role in this process, although to date only the Candida albicans Mdr1 transporter has been demonstrated to be relevant in the clinical acquisition of antifungal drug resistance. This work provides evidence to suggest the involvement of the C. glabrata DHA transporters CgAqr1, CgQdr2, CgTpo1_1, and CgTpo3 in the clinical acquisition of clotrimazole drug resistance. A screening for azole drug resistance in 138 C. glabrata clinical isolates, from patients attending two major Hospitals in Portugal, was performed. Based on this screening, 10 clotrimazole susceptible and 10 clotrimazole resistant isolates were selected for further analysis. The transcript levels of CgAQR1, CgQDR2, CgTPO1_1, and CgTPO3 were found to be significantly up-regulated in resistant isolates when compared to the susceptible ones, with a level of correlation that was found to be similar to that of CgCDR2, an ABC gene known to be involved in the clinical acquisition of resistance. As a proof-of-concept experiment, the CgTPO3 gene was deleted in an azole resistant C. glabrata isolate, exhibiting high levels of expression of this gene. The deletion of CgTPO3 in this isolate was found to lead to decreased resistance to clotrimazole and fluconazole, and increased accumulation of azole drugs, thus suggesting the involvement of this transporter in the manifestation of azole resistance.

No MeSH data available.


Related in: MedlinePlus