Banca de QUALIFICAÇÃO: DANILLO SALES ROSA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : DANILLO SALES ROSA
DATE: 27/02/2025
TIME: 09:00
LOCAL: Google Meet
TITLE:

GENOMIC CHARACTERIZATION OF Klebsiella pneumoniae COMING FROM AN OUTBREAK IN HUUNIVASF (PETROLINA, BRAZIL) AND APPLICATION OF A POLYPYRROL AND/OR ACID-BASED DETERGENT BENZOIC FOR SURFACE ANTISEPSY HOSPITAL

KEY WORDS:

Biofilm. Antimicrobial polymer. PPy. Resistome. Virulome

PAGES: 110
BIG AREA: Outra
AREA: Multidisciplinar
SUBÁREA: Biotecnologia
SUMMARY:

Klebsiella pneumoniae are bacteria widely distributed in hospital and community settings, and represent a major health threat due to severe infections and the lack of therapeutic options. Therefore, genetic factors that aid in the control and development of antimicrobial options have been investigated. In addition, developing strategies that improve the effectiveness of cleaning and disinfection of surfaces can reduce the transmission of these pathogens. In this sense, highly soluble polypyrrole (Hs-PPy) and benzoic acid (BA) are substances that have demonstrated antimicrobial action, and may aid in the elimination of biofilms formed by K. pneumoniae on hospital surfaces. Thus, the objective of this study was to evaluate the susceptibility of K. pneumoniae isolates and the potential of Hs-PPy and BA, alone and in combination, as antimicrobial agents and biofilm inhibitors, in addition to identifying resistance and virulence genes and evaluating the molecular epidemiology of these isolates. For this purpose, 47 isolates were characterized for antimicrobial susceptibility and 25 of these were used for the remaining analyses. The antimicrobial activity of Hs-PPy and BA was evaluated by broth microdilution. The ability to produce biofilm was investigated, as well as the interference of the substances on biofilm formation. The isolates had their genomic DNA extracted and sequenced. These sequences were assembled and annotated, and the resistance and virulence genes were identified. The isolates were characterized as multiresistant. More than 91% of the isolates were resistant to ampicillin, cefepime, ceftriaxone, levofloxacin, ertapenem, piperacillin-tazobactam, ampicillin-sulbactam, cefoxitin, cirpofloxacin, meropenem, imipenem and trimethoprim-sulfamethoxazole and 57.44% to polymyxin B. Amikacin and gentamicin were the antimicrobials that presented the highest sensitivity rates (95.74% and 51.06%, respectively). Hs-PPy did not demonstrate antimicrobial activity. BA presented inhibitory and bactericidal activity at 2 or 4 mg/mL. One isolate presented strong biofilm production and the others weak. The isolated and combined treatments did not interfere in the biofilm of the free-producing isolates, but inhibited it in the strong
producer. A total of 110 virulence-related genes and 82 resistance genes were predicted with similarity ≥80%. The KLPN_3174 genome had the highest number of virulence genes (95), while KLPN_3233 had the lowest number (75). The KLPN_5887, KLPN_6001, and KLPN_9273 genomes had fewer resistance genes, 39, 42, and 44 genes, respectively, while the others had 49 to 60 genes. Most of the predicted virulence genes involved adherence, nutritional/metabolic factor, effector delivery system, exotoxin, immune modulation, and biofilm, while resistance genes involved efflux, antibiotic targeting, reduced permeability, and antibiotic inactivation. In addition, the resistance genes identified in the K. pneumoniae isolates were related to a total of 28 antimicrobials from different classes. K. pneumoniae isolates presented a phenotypic profile of multidrug resistance and genomic analyses identified several genes of resistance to multiple antimicrobials, in addition to virulence genes, highlighting the complexity of the strains.

 

COMMITTEE MEMBERS:
Externa à Instituição - FRANCIELE MABONI SIQUEIRA - UFRGS
Externa à Instituição - FLÁVIA FIGUEIRA ABURJAILE - UFMG
Interna - ***.220.794-** - LARISSA ARAÚJO ROLIM - UNIVASF