Banca de DEFESA: EMMANOELLY ADRIANA DO NASCIMENTO TRIESTE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : EMMANOELLY ADRIANA DO NASCIMENTO TRIESTE
DATE: 03/03/2026
TIME: 14:00
LOCAL: https://meet.google.com/ror-zbpr-unc
TITLE:

MANGROVES AS A RESERVOIR FOR ANTIMICROBIAL-RESISTANT MICROORGANISMS: A ONE HEALTH ALERT

 

KEY WORDS:

Carbapenemase, Vancomycin resistance, Beta-lactamases, Multidrug-resistant bacteria

PAGES: 93
BIG AREA: Ciências Biológicas
AREA: Microbiologia
SUMMARY:

Mangroves are coastal wetlands strongly influenced by anthropogenic activities, including aquaculture practices. Such practices can favor the introduction and spread of antimicrobial-resistant microorganisms, posing a potential risk to environmental and public health. Given this scenario, the present study aimed to isolate and phenotypically characterize resistant microorganisms present in water, soil, and oyster samples collected from a mangrove located in the Gamboa Manimbu region, in the municipality of Natal/RN. Ten collection campaigns were carried out between September 2024 and September 2025 at two different points in the study area. The samples were initially cultured in peptone water supplemented with antibiotics and incubated for 24 hours at 37 °C, followed by seeding of 0.01 mL aliquots in selective media containing antibiotics for the isolation of resistant bacteria and yeasts. The plates were incubated at 37 °C for 48 hours for bacteria and at 30 °C for up to five days for yeasts. The isolates were identified by MALDI-TOF MS, while susceptibility to antibacterials was assessed by disk diffusion and phenotypic tests for the detection of β-lactamases in medically relevant bacterial groups, including Enterobacterales, non-fermenting Gram-negative bacilli (NFGNB), and Enterococcus spp. Antifungal susceptibility was determined by minimum inhibitory concentration (MIC) using broth microdilution. A total of 316 microorganisms were isolated, including 277 bacteria and 39 yeasts. Among the Escherichia coli isolates (n = 29), six had a profile suggestive of extended-spectrum β-lactamase (ESBL) production and two had ESBL/AmpC co-production. Among Klebsiella pneumoniae (n = 19), five isolates showed a profile suggestive of ESBL, one of ESBL/AmpC, and two of AmpC and NDM metallo-β-lactamase co-production. Additionally, three Proteus mirabilis isolates showed a profile suggestive of ESBL. Among BGN-NF, Pseudomonas spp. and Acinetobacter spp. were predominantly multisensitive to the antibiotics tested, while some isolates of Stenotrophomonas maltophilia showed resistance to sulfamethoxazole-trimethoprim. In Enterococcus spp., six isolates showed resistance to glycopeptides. Regarding yeasts, one isolate of Pichia kudriavzevii showed resistance to caspofungin and high MIC for tebuconazole, an environmental fungicide; additionally, two isolates of Meyerozyma guilliermondii and one of Candida tropicalis also exhibited high MICs for tebuconazole. Taken together, the results show that the mangrove studied acts as an important environmental reservoir of antimicrobial-resistant microorganisms, reinforcing the need for continuous monitoring of these ecosystems and integrated prevention and control strategies from a One Health perspective.

COMMITTEE MEMBERS:
Interna - 1452833 - MARIA CELESTE NUNES DE MELO
Externa à Instituição - QUÉZIA MOURA DA SILVA - IFES
Presidente - 1143204 - RAFAEL WESLEY BASTOS