Electronic equipment and appliances in special wards of hospitals as a source of azole-resistant Aspergillus fumigatus: a multi-centre study from Iran

BACKGROUND

Azole-resistant Aspergillus fumigatus (ARAf), reported as a global public health concern, has been unexpectedly observed in different countries.

AIM

To identify ARAf and detect azole resistance related to the CYP51A mutation in different hospital environmental samples.

METHODS

In this multi-centre study from Iran, surfaces of electronic equipment and appliances from different hospitals in Iran were sampled using cotton swabs. All samples were cultured using azole-containing agar plates (ACAPs). Recovered Aspergillus isolates were identified at the species level using partial DNA sequencing of the β-tubulin gene. The azole susceptibility testing of A. fumigatus isolates was performed using the Clinical and Laboratory Standards Institute M38-A3 guideline. The sequencing of the CYP51A gene was also performed to detect mutations related to resistance.

FINDINGS

Out of the 693 collected samples, 89 (12.8%) Aspergillus species were recovered from ACAPs. Aspergillus fumigatus (41.6%) was the most prevalent, followed by A. tubingensis (23.6%) and A. niger (15.6%). Among 37 isolates of A. fumigatus, 19 (51.3%) showed high minimum inhibitory concentration (MIC) values to at least one of the three azoles, voriconazole, itraconazole, and posaconazole. CYP51A polymorphisms were detected in all 19 isolates, of which 52.6% showed the TR34/L98H mutation. Other detected mutations were G432C, G448S, G54E/G138C, F46Y, and Y121F/M220I/D255E. T289F and G432C were the first reported mutations in ARAf.

CONCLUSION

There was a considerable level of azole resistance in hospital environmental samples, a serious warning for patients vulnerable to aspergillosis. Our findings have also revealed a different mutation pattern in the CYP51A gene.

In vitro activity of econazole in comparison with three common antifungal agents against clinical Candida strains isolated from superficial infections

Background and Purpose:

Candida species are the most common organisms involved in superficial fungal infections, worldwide. Although econazole is among the most frequently used topical formulations for the treatment of candidiasis, no information is available regarding the susceptibility profiles of Candida species in Iran.

Materials and Methods:

In vitro susceptibility of 100 clinical Candida isolates belonging to 6 species from superficial candidiasis of Iran towards to econazole was compared with three other common antifungal agents including itraconazole, fluconazole, and miconazole. Minimum inhibitory concentrations (MICs) values were analyzed according to the Clinical and Laboratory Standards Institute (CLSI) M38-A3 document. All isolates were previously identified to the species level, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) on ITS region.

Results:

The MIC of econazole, itraconazole, miconazole, and fluconazole were within the range of 0.016-16, 0.032-16, 0.016-16, and 0.25-64 μg/ml, respectively. In general, econazole and miconazole were more active against Candida isolates, compared to the other two agents.

Conclusion:

The present study demonstrated that for Candida albicans isolates, miconazole and econazole had the best effect, but in non-albicans Candida species, itraconazole and miconazole displayed more activity than other antifungal agents.

Evaluation of the antifungal activities of various extracts from Pistacia atlantica Desf

Background and Purpose:

Despite the availability of various treatments for fungal diseases, there are some limitations in the management of these conditions due to multiple treatment-related side-effects. The present study was designed to investigate the antifungal properties of different extracts from Pistacia atlantica Desf.

Materials and Methods:

Different parts of P. atlantica (i.e., dried fruit, fresh fruit and dried leaf) were separately extracted via percolation method with 80% methanol and water. Gas chromatography/mass spectrometry (GC/MS) analysis was performed to determine the main constituents of leaf and fruit extracts from P. atlantica. In vitro anti-Candida activities of the extracts against Candida albicans, Candida glabrata and Saccharomyces cerevisiae were studied. For this purpose, the minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) were determined, using broth microdilution method, according to the modified M27-A3 protocol on yeasts, proposed by the Clinical and Laboratory Standards Institute (CLSI).

Results:

Based on GC/MS analysis, the main constituents of P. atlantica fruit extracts were β-myrcene (41.4%), α-pinene (32.48%) and limonene (4.66%), respectively, whereas the major constituents of P. atlantica leaf extracts were trans-caryophyllene (15.18%), α-amorphene (8.1%) and neo-allo-ocimene (6.21%), respectively. As the findings indicated, all the constituents exhibited both fungistatic and fungicidal activities, with MICs ranging from 6.66 to 26.66 mg/mL and MFCs ranging from 13.3 to 37.3 mg/mL, respectively. Among the evaluated extracts, the methanolic fresh fruit extract of P. atlantica was significantly more effective than other extracts (P<0.05).

Conclusion:

Based on the findings of the present study, novel antifungal agents need to be developed, and use of P. atlantica should be promoted in the traditional treatment of Candida infections.