Genotyping of paired KPC-producing Klebsiella pneumoniae isolates with and without divergent polymyxin B susceptibility profiles
| Autor: | Cely Barreto da Silva, Rozane de Lima Bigelli Carvalho, Aline Valerio de Lima, Jorge Luiz Mello Sampaio, Darlan Augusto da Costa Rocha, Lycia Mara Jenné Mimica, Suely Carlos Ferreira Sampaio, Keila de Oliveira Lima, Marcelo Jenne Mimica |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
medicine.medical_specialty
Clinical Microbiology - Research Paper Genotype medicine.drug_class Klebsiella pneumoniae Polymyxin Microbial Sensitivity Tests Biology PLACEBOS Microbiology Medical microbiology Bacterial Proteins Multiplex polymerase chain reaction Drug Resistance Bacterial Media Technology medicine Humans Genotyping Polymyxin B Broth microdilution Antimicrobial biology.organism_classification Anti-Bacterial Agents Klebsiella Infections Brazil medicine.drug |
| Zdroj: | Braz J Microbiol Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | Polymyxins are still used mainly in treating infections caused by carbapenem-resistant Klebsiella pneumoniae worldwide. The most frequent mechanism of acquired resistance to polymyxins in Gram-negative bacilli is the occurrence of mutations in chromosomal genes regulating operons responsible for lipopolysaccharide modification. As we observed at Santa Casa de São Paulo hospital the occurrence of infections caused by isolates resistant to polymyxins in patients previously treated with this antimicrobial, and new infections caused by the same polymyxin-susceptible species, in this study, we aimed to determine the clonality of consecutive K. pneumoniae isolates from the same patients and characterize the molecular determinants of polymyxin resistance in paired or clonal isolates. A total of 24 pairs and one trio of K. pneumoniae isolates were included in this study. Species identification was achieved by mass spectrometry and multiplex PCR. Polymyxin B minimal inhibitory concentrations were determined by broth microdilution. Clonality was evaluated using pulsed-field gel electrophoresis. The presence of insertions in mgrB gene was tested by PCR, and mutations on pmrA, pmrB, phoP, and phoQ were evaluated by PCR and complete nucleotide sequencing. A fraction of 23.8% of strains resistant to polymyxin B had an insertion in mgrB. Amino acid substitution F204L in PmrB may be implicated in polymyxin resistance. Substitutions T246A and R256G in PmrB were not implicated in polymyxin resistance. In this study, polymyxin resistance after a first susceptible isolate was detected was most frequently due to an infection caused by a distinct clone. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42770-021-00600-5. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|