Evaluation of an adapted method of relative growth to determine the susceptibility of Enterobacterales to polymyxin B by MALDI-TOF MS.
Braz J Microbiol
; 54(3): 1841-1846, 2023 Sep.
Article
in En
| MEDLINE
| ID: mdl-37402940
Polymyxin B resistance is an emerging problem worldwide. The reference method to determine susceptibility to polymyxins is broth microdilution (BMD). As BMD is time consuming, it is necessary to develop new methodologies to provide faster evaluation of polymyxin susceptibility. This study aimed to evaluate polymyxin B susceptibility of Enterobacterales using an adapted methodology of relative growth (RG) by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). A total of 60 isolates of Enterobacterales (22 resistant and 38 susceptible to polymyxin B by BMD) were evaluated. The adapted RG technique presented categorical agreement of 96.7% with only 2 major errors (3.3%) in comparison to BMD. Our findings demonstrate a high agreement between BMD and adapted RG, indicating that this methodology is promising for differentiating polymyxin B-susceptible isolates from polymyxin B-resistant isolates and could be implemented routinely in microbiology laboratories that already use the MALDI-TOF MS to identify bacteria.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polymyxin B
/
Anti-Bacterial Agents
Type of study:
Prognostic_studies
Language:
En
Journal:
Braz J Microbiol
Year:
2023
Document type:
Article
Affiliation country:
Brazil
Country of publication:
Brazil