| Congresso Brasileiro de Microbiologia 2023 | Resumo: 750-1 | ||||
Resumo:Pseudomonas aeruginosa and Acinetobacter baumannii are pathogens of great clinical importance, responsible for difficult-to-treat nosocomial infections, especially when dealing with multidrug-resistant strains. In Brazil, the resistance rate to carbapenems may exceed 60%, and carbapenemase production is the main mechanism reported in these species. In this context, the importance of effective, low-cost, and highly reproducible tests for identifying the production of these enzymes is evident. The carbapenem inactivation method (CIM) and its variations are generally simple to perform and interpret, requiring no expensive materials, which facilitates their implementation in various clinical microbiology laboratories. The present study aimed to detect carbapenemases in clinical isolates of A. baumannii and P. aeruginosa resistant to at least one carbapenem, collected from a public hospital in Mossoró-RN, during the period from 2020 to 2022. It included 30 isolates of A. baumannii and 22 of P. aeruginosa, which were tested using the modified CIM (mCIM), EDTA-modified CIM (eCIM), and simplified CIM (sCIM). Among the A. baumannii isolates, 29 (96.7%) tested positive in at least one of the tests, indicating the presence of carbapenemases. For mCIM, only 3 (10%) isolates tested positive, with 2 (6.7%) being metallo-&beta-lactamase producers in eCIM. In sCIM, 26 (86.67%) of the isolates presented positive results. Among the P. aeruginosa isolates, according to the mCIM/eCIM results, 6 did not produce carbapenemases (27%), 6 were metallo-&beta-lactamase producers (27%), and 10 were serine-carbapenemase producers (45%). In sCIM, 9 were carbapenemase producers (41%), 8 were non-producers (36%), and 5 were inconclusive (23%). Furthermore, there was a disagreement in 36% of the tests between mCIM and sCIM results, as sCIM may have low performance for P. aeruginosa. On the other hand, regarding A. baumannii, there was a 100% disagreement between mCIM and sCIM, indicating that mCIM has low performance for this species. Thus, the present study allowed the identification of carbapenemase production in isolates of A. baumannii and P. aeruginosa using different phenotypic tests, concluding that sensitivity depends on the species in question, as well as the type of carbapenemase produced, and it is necessary to assess factors such as available resources and local endemicity for the appropriate choice of the best methodology. Palavras-chave: Acinetobacter baumannii, Pseudomonas aeruginosa, carbapenemase, beta-lactamases | |||||