Dados do Trabalho

Título

Phenotypic and molecular characterization of carbapenem-resistant Klebsiella pneumoniae identified a high prevalence of blaNDM in a tertiary hospital in Mossoró, RN

Introdução

Klebsiella pneumoniae is a Gram-negative, nonmotile, encapsulated, rod-shaped bacillus that causes hospital infections. Due to its genetic characteristics, it is intrinsically resistant to penicillins and can acquire resistance to other antimicrobials. Among the main resistance mechanisms of K. pneumoniae is the production of carbapenemase enzymes, with the most common being: KPC, NDM, and OXA-48. 

Objetivo (s)

To characterize the antimicrobial resistance profile and detect the production of carbapenemases in multidrug-resistant K. pneumoniae isolates recovered from hospitalized patients in Mossoró, RN. 

Material e Métodos

This study was approved by the Ethics Committee (Nº 6.098.878). Between January 2023 and August 2024, isolates identified as K. pneumoniae with resistance to at least one carbapenem were obtained by convenience from the microbiology laboratory of the Tarcísio Maia hospital in Mossoró, RN; The samples were transported to the laboratory LABMIC at UFERSA and inoculated onto MacConkey agar at 37°C for 24 hours followed by conventional biochemical tests (Simmons Citrate, Triple Sugar Iron, Urea, Lysine, and Sulfite Indole Mobility) to reconfirm species and purity. The isolates underwent antimicrobial susceptibility testing (AST) by disk diffusion, carbapenem inactivation tests (mCIM and eCIM), and PCR for NDM and KPC coding genes.

Resultados e Conclusão

A total of 14 isolates identified as K. pneumoniae were included. Regarding the susceptibility profile, 85.7% (12) showed resistance to meropenem, followed by 85.7% (12) to cefotaxime, 66.6% (8) to imipenem, and 100% to ciprofloxacin. Additionally, 41.6% (5) showed susceptibility to sulfamethoxazole-trimethoprim. All isolates tested positive for carbapenemase production; 10 (71.42%) were metallo-β-lactamase producers, and 4 (28.6%) were serine β-lactamase producers. This was confirmed by molecular tests, in which 71.4% (10) were identified as NDM producers, while 2 (14.3%) were identified as KPC producers. The high percentage of antimicrobial resistance to antibiotics signals a warning for its administration. Furthermore, this study determined that 85% of the isolates are carbapenemase producers, predominantly NDM, contrary to the prevalence of KPC-type enzymes in Brazil, highlighting the need for further investigation in this hospital environment.

Palavras Chave

Klebsiella pneumoniae; Carbapenemases; Hospital infection; Antimicrobial Drug Resistance