Norida Vélez

Background: Candida parapsilosis is an opportunistic yeast of increasing clinical importance, with fluconazole resistance rates rising globally and reaching concerning levels in clinical settings across several countries, including Colombia. However, the occurrence of antifungal-resistant Candida species in domestic water systems in the country remains largely unexplored. Methods: This cross-sectional study assessed the occurrence and antifungal susceptibility of Candida spp. in intradomiciliary water from 104 households in Villavicencio, Colombia, during two monitoring periods. Water samples were filtered, and yeast-like colonies were identified using MALDI-TOF mass spectrometry. Susceptibility to fluconazole, amphotericin B, and anidulafungin was determined using the CLSI broth microdilution method. The ERG11 gene was sequenced in the fluconazole-resistant isolate. Results: C. parapsilosis was recovered from 16 of 104 households (15.4%), yielding 22 isolates distributed across six communes. Most isolates (72.7%) were obtained from household water storage tanks. One isolate was resistant to fluconazole (MIC = 8 µg/mL) and harbored a nonsynonymous R398I substitution in ERG11. Conclusions: To our knowledge, this is the first report of C. parapsilosis, including a fluconazole-resistant isolate carrying an ERG11 substitution, recovered from domestic water in Colombia. These findings suggest that household water storage tanks may serve as environmental reservoirs for this opportunistic yeast. The implications for human exposure remain to be determined and highlight the need for integrated One Health surveillance.

Background: Candida parapsilosis is an opportunistic yeast of increasing clinical importance, with fluconazole resistance rates rising globally and reaching concerning levels in clinical settings across several countries, including Colombia. However, the occurrence of antifungal-resistant Candida species in domestic water systems in the country remains largely unexplored. Methods: This cross-sectional study assessed the occurrence and antifungal susceptibility of Candida spp. in intradomiciliary water from 104 households in Villavicencio, Colombia, during two monitoring periods. Water samples were filtered, and yeast-like colonies were identified using MALDI-TOF mass spectrometry. Susceptibility to fluconazole, amphotericin B, and anidulafungin was determined using the CLSI broth microdilution method. The ERG11 gene was sequenced in the fluconazole-resistant isolate. Results: C. parapsilosis was recovered from 16 of 104 households (15.4%), yielding 22 isolates distributed across six communes. Most isolates (72.7%) were obtained from household water-storage tanks. One isolate was resistant to fluconazole (MIC = 8 µg/mL) and harbored a nonsynonymous R398I substitution in ERG11. Conclusions: To our knowledge, this is the first report of C. parapsilosis, including a fluconazole-resistant isolate carrying an ERG11 substitution, recovered from domestic water in Colombia. These findings suggest that household water-storage tanks may serve as environmental reservoirs for this opportunistic yeast. The implications for human exposure remain to be determined and highlight the need for integrated One Health surveillance.

The World Health Organization (WHO) prioritized 19 fungal species based on the significant impact of these pathogens on human health, including the emergence of antifungal resistance, which highlights the necessity of finding new antifungal therapies. Among these novel therapeutic approaches, the antimicrobial pore-forming peptide C14R has shown to be promising against Candida albicans and Candida auris. In this study, the antifungal in vitro efficacy of C14R was assessed against six additional species from the WHO priority list, Cryptococcus neoformans, Cryptococcus gattii, Candida glabrata, Candida tropicalis, Candida parapsilosis and Candida krusei, as well as against Candida dubliniensis. This study shows that C14R has good antifungal activity against several clinical isolates of the studied species, with MIC values between 0.8476 and 10.88 µg/mL. Most notably, some of the studied isolates are resistant to commonly used antifungal drugs but are susceptible to the peptide. C14R showed, moreover, its capacity to disrupt Cryptococcus capsules, beyond its already proven capacity to disrupt plasma membranes, and its antifungal activity was not affected depending on the serotype or species assessed. The inclusion of basidiomycete and ascomycete yeasts allowed us to display the broad-spectrum potential of C14R, highlighting it as a promising candidate as an antifungal agent.

Background: Mental well-being plays a pivotal role within the broader spectrum of health and illness, encompassing factors such as stress, depression, and anxiety. Nature-based therapeutic interventions have emerged as a promising approach to addressing these mental health challenges. This study seeks to assess the impact of these interventions on stress, depression, and anxiety levels. Methods: We conducted an extensive search for randomized clinical trials that examined stress, anxiety, and depression levels. The selected studies underwent a rigorous risk-of-bias assessment following the guidelines outlined in the Cochrane Handbook for Systematic Reviews. Results: Our review encompassed findings from eight publications. Among them, two studies measuring cortisol levels revealed significant differences between the pre-test and post-test measurements within the intervention groups. In two studies that employed the Stress Response Inventory, a significant decrease in stress levels was observed within the intervention groups in contrast to the control groups. However, no significant differences were noted in studies that utilized the Restorative Outcome Scale. In the assessment of anxiety and depression levels, three studies employed the Positive and Negative Affect Schedule, while four studies utilized The Profile of Mood States scale; none of these studies demonstrated significant differences. Conclusions: The current body of evidence offers limited support for advocating nature-based therapeutic interventions as a primary approach to reducing stress, depression, and anxiety.

Cryptococcosis is a potentially fatal opportunistic mycosis that affects the lungs and central nervous system. It has been suggested that certain strains of C. neoformans/C. gattii may have the potential to be more virulent according to the molecular type. This study aims to investigate the association between virulence in the G. mellonella model and genotypic diversity of Colombian clinical and environmental isolates of C. neoformans/C. gattii. A total of 33 clinical and 12 environmental isolates were selected according to their geographical origin and sequence types (STs). Pathogenicity was determined using the G. mellonella model, and the cell and capsular size before and after inoculation was determined. For C. neoformans, virulence in G. mellonella revealed that death occurred on average on day 6 (p < 0.05) and that ST5C, 6C, 25C and 71C were the most virulent. In C. gattii, death occurred at 7.3 days (p < 0.05), and ST47C, 58C, 75A and 106C were the most virulent. Capsular size increased for both species after passage in G. mellonella. In conclusion, the pathogenicity of Cryptococcus strains in the G. mellonella invertebrate model is independent of molecular type or pathogenicity factor, even within the same ST, but it is possible to find variable degrees of pathogenicity.

The environmental isolation of Cryptococcus spp. is typically a difficult undertaking. Collecting samples in the field is costly in terms of travel, personnel time and materials. Furthermore, the recovery rate of Cryptococcus spp. may be very low, thereby requiring a large number of samples to be taken without any guarantee of success. Ecological niche modeling is a tool that has traditionally been used to forecast the distribution of plant and animal of species for biodiversity and conservation purposes. Here, we use it in a public health application to produce risk area maps for cryptococcal disease in Colombia. The Genetic Algorithm for Ruleset Production (GARP) was used to create models for Cryptococcus neoformans (C. neoformans) and Cryptococcus gattii (C. gattii), based on environmental sampling and clinical records data recorded since 1987. These maps could be used to focus public health messaging related to cryptococcal disease, and it enables us to characterize the ecological niche for Cryptococcus in Colombia. We found that the OPEN ACCESS J. Fungi 2015, 1 333 ecological niche for C. gattii in Colombia is quite diverse, establishing itself in sub-tropical and temperate ecoregions within the country. This suggests that C. gattii is highly adaptive to different ecological conditions in Colombia and different regions of the world.