Emergence of azole-resistant Candida albicans in small ruminants

Azole resistance in Candida from animals calls for the One Health approach to tackle the emergence of antimicrobial resistance

This study initially aimed at investigating the occurrence of azole resistance among Candida spp. from animals and analyzing the involvement of efflux pumps in the resistance phenomenon. Then, the dynamics of antifungal resistance was assessed, by comparing the antifungal epidemiological cutoff values (ECVs) against C. albicans and C. tropicalis from humans and animals. Fifty azole-resistant isolates (24 C. albicans, 24 C. tropicalis; 2 C. parapsilosis sensu lato) were submitted to the efflux pump inhibition assay with promethazine and significant MIC reductions were observed for fluconazole (2 to 250-fold) and itraconazole (16 to 4000-fold). Then, the antifungal ECVs against C. albicans and C. tropicalis from human and animal isolates were compared. Fluconazole, itraconazole and voriconazole ECVs against human isolates were lower than those against animal isolates. Based on the antifungal ECVs against human isolates, only 33.73%, 50.39% and 63.53% of C. albicans and 52.23%, 61.85% and 55.17% of C. tropicalis from animals were classified as wild-type for fluconazole, itraconazole and voriconazole, respectively. Therefore, efflux-mediated mechanisms are involved in azole resistance among Candida spp. from animals and this phenomenon seems to emerge in animal-associated niches, pointing to the existence of environmental drivers of resistance and highlighting the importance of the One Health approach to control it.

Diversity and functions of the sheep faecal microbiota: a multi-omic characterization

Little is currently known on the microbial populations colonizing the sheep large intestine, despite their expected key role in host metabolism, physiology and immunity. This study reports the first characterization of the sheep faecal microbiota composition and functions, obtained through the application of a multi-omic strategy. An optimized protocol was first devised for DNA extraction and amplification from sheep stool samples. Then, 16S rDNA sequencing, shotgun metagenomics and shotgun metaproteomics were applied to unravel taxonomy, genetic potential and actively expressed functions and pathways respectively. Under a taxonomic perspective, the sheep faecal microbiota appeared globally comparable to that of other ruminants, with Firmicutes being the main phylum. In functional terms, we detected 2097 gene and 441 protein families, finding that the sheep faecal microbiota was primarily involved in catabolism. We investigated carbohydrate transport and degradation activities and identified phylum-specific pathways, such as methanogenesis for Euryarchaeota and acetogenesis for Firmicutes. Furthermore, our approach enabled the identification of proteins expressed by the eukaryotic component of the microbiota. Taken together, these findings unveil structure and role of the distal gut microbiota in sheep, and open the way to further studies aimed at elucidating its connections with management and dietary variables in sheep farming.

Candida growth in urine cultures: a contemporary analysis of species and antifungal susceptibility profiles

BACKGROUND

Recent publications suggest the distribution of Candida species causing candiduria may vary geographically, which has implications for the continued efficacy of antifungal therapy and emerging resistance.

AIM

To investigate the incidence of Candiduria at a university hospital in the UK. Further, to assess the distribution of species and the accompanying antifungal susceptibility profile, in order to monitor the clinical utility of current antifungal treatment guidelines for candiduria so that patients receive the best possible outcomes from the most up to date care.

DESIGN

Retrospective audit.

METHODS

From 1st January 2005 to 31st October 2014, we retrospectively reviewed 37 538 positive urine cultures recorded in a computerized laboratory results database. Identification and susceptibility testing was performed using the VITEK® 2 fungal susceptibility card (bioMérieux, Marcy d'Etoile, France).

RESULTS

In total, 96 cultures were positive for Candida species, of which 69 (72%) were C.albicans, which translates to a prevalence of 2.6 per 1000 positive urine cultures. Candiduria was more common in younger patients, males and catheterized females. We report 94 and 73% of isolates of C.albicans and other non-C.albicans Candida species were susceptible to fluconazole. All isolates were susceptible to amphotericin B.

CONCLUSIONS

Our results add weight to the evidence supporting current European and North American guidelines recommending fluconazole or amphotericin B for treatment of candiduria, if antifungal treatment is clinically indicated.