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/udy-gupq-qxk
TITLE:

MANGROVE FOREST AS A RESERVOIR FOR ANTIMICROBIAL RESISTANT MICROORGANISMS: A ONE HEALTH ALERT

 

 

KEY WORDS:

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

PAGES: 84
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. With
regard to yeasts, an isolate of Pichia kudriavzevii showed resistance to caspofungin and high MIC for
tebuconazole, an environmental fungicide; in addition, two isolates of Meyerozyma guilliermondii had high
MICs for tebuconazole, and two isolates of Candida tropicalis also exhibited high MICs, with one isolate
resistant to tebuconazole and another to fluconazole. 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:
Presidente - 1143204 - RAFAEL WESLEY BASTOS
Interna - 1452833 - MARIA CELESTE NUNES DE MELO
Externa à Instituição - QUÉZIA MOURA DA SILVA - IFES