ABSTRACT
OBJECTIVES: To determine the trends of antimicrobial resistance for Acinetobacter baumannii complex isolates recovered from inpatients over a 4-year follow-up survey. METHODS: A total of 659 A baumannii complex isolates were recovered from hospitalized patients in Porto Alegre and its metropolitan area, Southern Brazil, from 2017 to 2020. Susceptibility profile was determined for ampicillin/sulbactam, amikacin, gentamicin, imipenem, meropenem, minocycline, polymyxin B and tigecycline. RESULTS: Overall, PMB was the most active agent against the set of A baumannii isolates over the period. Although stable, a high resistance rate was observed. CONCLUSIONS: Our results shown the presence of an extensively-drug resistant A baumannii complex isolates over the past four years. Polymyxin B has been the only antimicrobial agent that remain with a good in vitro activity. Strict surveillance and infection control measures are mandatory.
Subject(s)
Acinetobacter Infections , Acinetobacter baumannii , Acinetobacter Infections/drug therapy , Acinetobacter Infections/epidemiology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Brazil , Carbapenems , Drug Resistance, Bacterial , Drug Resistance, Multiple, Bacterial , Follow-Up Studies , Humans , Inpatients , Microbial Sensitivity TestsABSTRACT
BACKGROUND: To determine the turnaround time from a blue-carba result until a final microbiological report (bacterial identification plus antimicrobial susceptibility profile) and to infer the impact of an early therapeutic intervention based on the blue-carba results. METHODS: Pseudomonas aeruginosa isolates were recovered from hospitalized patients from Porto Alegre, Brazil, and tested by blue-carba test. Time required for a blue-carba result, right after the sample processing, was compared with those required to get final report (specie identification and antimicrobial susceptibility profile) Isolates blue-carba positive were tested by phenotypically and genotypically for Klebsiella pneumoniae carbapenemase and metallo-ß-lactamase genes. RESULTS: A total of 199 isolates were analyzed and 23 (11.6%) were blue-carba positive and harboring the blaSPM-1-like gene. Fifty-two (26.1%) isolates were blue-carba negative but resistant to meropenem and/or imipenem. Polymyxin B and ceftolozane/tazobactam (this latter except for SPM-1 producers) were 100% active for all P. aeruginosa isolates, a blue-carba test allow an earlier intervention or adequacy of therapy. CONCLUSIONS: Early adequacy can be promoted by blue-carba test for 11.6% of SPM-1-producing P. aeruginosa isolates, polymyxin B could be prior associated and ceftolozane/tazobactam withdrawn from therapy. For the remaining isolates, empirical therapy involving ceftolozane/tazobactam can be maintained with greater likelihood of adequacy. An active communication between laboratory and clinical services is necessary to better explore these earlier blue-carba results, significantly reducing the time for a first intervention.
Subject(s)
Pseudomonas Infections , Pseudomonas aeruginosa , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Proteins , Brazil , Cephalosporins , Humans , Microbial Sensitivity Tests , Pseudomonas Infections/drug therapy , Secondary Prevention , beta-Lactamases/geneticsABSTRACT
To assess the performance of the drop test for polymyxin B resistance detection among Enterobacterales and non-fermentative gram-negative rods resistant to carbapenems. Seven hundred and fifteen carbapenem-resistant isolates were tested: 628 Enterobacterales species and 87 non-fermentative gram-negative rods. For the polymyxin drop test, concentrations range from 0.25 to 8.0 µg/mL. Broth microdilution, as gold standard, was performed using in-house-prepared panels and interpreted according to the CLSI guidelines. Results were interpreted in terms of categorical agreements and discrepancies. Accuracy for a drop of polymyxin B at 2.0, 4.0 and 8.0 was calculated as better cutoff for resistance determination. No very major error was observed among all isolates, and 95.5% of agreement was observed among Enterobacterales, particularly for Klebsiella pneumoniae. A higher accuracy (95.1%) was obtained when a single drop of polymyxin B at 4.0 µg/mL was applied. Polymyxin drop test presented >95% of categorical agreement, without very major errors, for KPC-producing K. pneumoniae isolates. An accuracy of 95.1% was obtained with a single drop at 4.0 µg/mL polymyxin B. Polymyxin B drop is an easy and feasible test and may allow a reduction on the turnaround time for polymyxin resistance detection and impacting on early implementation of accurate therapeutic interventions.
