Banca de DEFESA: ANA BEATRIZ NASCIMENTO DE MACEDO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA BEATRIZ NASCIMENTO DE MACEDO
DATE: 19/04/2024
TIME: 14:00
LOCAL: Defesa remota: https://meet.google.com/jmr-wjjs-fcr
TITLE:

METABOLIC INTERACTION BETWEEN THE FUNGUS Candida auris AND THE BACTERIA Pseudomonas aeruginosa

KEY WORDS:

Candida auris; Antagonistic Actions; Microbial Interactions; Pseudomonas
aeruginosa; Secondary metabolites.

PAGES: 80
BIG AREA: Ciências Biológicas
AREA: Microbiologia
SUBÁREA: Biologia e Fisiologia dos Microorganismos
SPECIALTY: Bacterologia
SUMMARY:

In hospital environments, a range of microorganisms harmful to human health can be found. Among them is the bacterium Pseudomonas aeruginosa (P.a14), which is a non-fermenting gram-negative bacillus, motile, oxidase-positive, and ubiquitously found in nature. In the hospital context, we also encounter Candida auris (Cau), an emerging pathogenic fungus that is highly resistant to hospital disinfection and challenging to control nosocomial infections. Little is known about how C. auris interacts with such bacteria in the hospital environment and in the host. Therefore, the aim of this study was to investigate the interaction between Candida auris and the bacterium Pseudomonas aeruginosa. Initially, we investigated whether there was antagonism between Candida albicans (Cal) and P. aeruginosa through co-culturing in liquid medium, showing that P. aeruginosa significantly inhibited yeast growth. Similarly to Cal, P.a14 also inhibited Cau growth in a similar manner. This inhibition occurred regardless of the inoculum concentration used and began between 8 and 12 hours, persisting for up to 120 hours, the longest time tested in this experiment. It was then observed that there was no inhibition when cell-free filtrate was used, both from P.a14 and Candida spp. isolates, suggesting that the presence of cells is necessary for inhibition. Furthermore, it was observed that P.a14 inhibited the yeasts regardless of the medium used, including RPMI, YPD, RPMI 2x, and RPMI supplemented with 2% glucose, suggesting that inhibition does not occur solely due to nutrient competition. However, when iron was added to the RPMI medium, it was observed that Cau resisted the inhibition caused by P.a14. Additionally, P.a14 was able to inhibit other strains of Cau during interactions, demonstrating a consistent pattern of inhibition among the different yeast strains studied. In conclusion, P.a14 inhibits Cau growth similarly to the inhibition of C. albicans, and this process needs to be further characterized, possibly being directly influenced by the production of antagonistic substances with antifungal activity, or competition for important nutrients for its metabolism.

COMMITTEE MEMBERS:
Externo à Instituição - GUSTAVO JOSÉ COTA DE FREITAS - UFMG
Externa à Instituição - JULLIANA RIBEIRO ALVES DOS SANTOS
Interna - 1452833 - MARIA CELESTE NUNES DE MELO
Presidente - 1143204 - RAFAEL WESLEY BASTOS