Browsing by Author "MacGilchrist, Claire"
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- Detection of dermatophytes in the environment of a podiatry clinicPublication . Sabino, Raquel; Aranha Caetano, Liliana; Veríssimo, Cristina; Coggins, Ann Marie; Fleming, Gerard T.; Roberts, Nigel; MacGilchrist, Claire; Viegas, CarlaObjectives: Podiatry is a healthcare profession that specializes in the management of disorders of the lower limb and foot. Podiatric treatments have the potential to generate substantial concentrations of organic dusts. Occupational exposure to bioaerosols in podiatry clinics has been studied, but it was never accessed in a deeply manner for fungi. The detection of dermatophytes in podiatric clinics is a matter of concern since the environmental presence of these fungi can contribute to spread the infection to podiatry workers and to other patients consulted in the podiatry clinics. The aim of the present study was to characterize the dermatophyte burden during podiatric activities by the use of cultural methods but also molecular methodologies for fungal DNA detection directly from the collected samples. Methods: During the period of 4 weeks, environmental samples from a podiatric clinic were collected for both conventional and molecular methodologies. For culture, 44 air samples and 39 swabs from surfaces were inoculated in Mycosel agar. Fourteen air samples from the same sampling sites were collected for direct detection of fungal DNA. Air samples ranging from 88 to 300L were collected using a calibrated impinger device (Midget ImpingeR WITH Universal Sample Pump, SKC (PA, USA), at 2.2L/min airflow rate. Five milliliters of the collection liquid was used for DNA extraction using the ZR Fungal/Bacterial DNA MiniPrep Kit Detection of dermatophytes species (in general) and Trichophyton rubrum (in particular) were both achieved by using the Dermatophyte PCR kit, (SSI Diagnostica, Herredsvejen Hillerød, Denmark). PCR amplifications were performed using 2 μL and 5 μL of the extracted DNA. Results: In the first week, 1 out of 17 samples had a positive result for Trichophyton rubrum (detected in an air sample), whereas in the remaining weeks, no dermatophytes were identified in the remaining 129 samples (weeks 2, 3 and 4). The molecular detection of dermatophytes was performed in the 14 air samples using two different DNA volumes: 2 and 5 µl. Using 2 µl of the extracted DNA, 1 out 14 samples gave a positive result for T. rubrum and none of the PCR reactions was inhibited. Using a 5 µl volume of DNA, 5 samples were positive for T. rubrum but the PCR reaction was inhibited in 6 of them (Table 1). Globally, 5 out of the 14 (36%) samples analyzed showed positive results for the detection of T. rubrum DNA. Conclusions: Giving the ratio of positive/inhibited PCR reactions, we cannot rule out the hypothesis of more positive samples. Nevertheless, the obtained results emphasize the importance of the application of new methodologies for an air quality assessment approach and reinforce the complementarity of both cultural and conventional methodologies. To our knowledge, this study presents for the first time, the application of the Dermatophyte PCR kit for dermatophyte DNA detection directly from environmental samples (air). The promising results indicate the need of optimization of this procedure specifically in this type of samples in order to use this methodology in a routine basis, for occupational and indoor air quality exposure assessments.
- Fungal burden exposure assessment in podiatry clinics from IrelandPublication . Viegas, Carla; Coggins, Ann Marie; Faria, Tiago; Caetano, Liliana Aranha; Quintal Gomes, Anita; Sabino, Raquel; Veríssimo, Cristina; Roberts, Nigel; Watterson, David; MacGilchrist, Claire; Fleming, Gerard T.AFungi are amongst the bioaerosols of most importance, as indicated by the growing interest in this field of research. The aim was to characterize the exposure to fungal burden in podiatry clinics using culture-based and molecular methods. Methods: Airborne fungi were collected using an impaction air sampler and surface samples were also performed. Fourteen air samples were collected for direct detection of fungal DNA from filamentous fungi and dermatophytes. Overall, 63.6 % of the evening samples and 46 % of the morning samples surpassed the threshold values (150 CFU/ m3). Molecular detection, by real time PCR, of the target fungal species/ strains (Aspergillus and Stachybotrys species) was negative for all samples collected. Trichophyton rubrum was detected by PCR analysis in one DNA sample collected on day six. Results suggest the use of both culture-based and molecular methodologies are desirable for a complete evaluation of fungal burden in this particular health care setting.
