A carbapenem-resistant Acinetobacter baumannii outbreak associated with a polymyxin shortage during the COVID pandemic: an in vitro and biofilm analysis of synergy between meropenem, gentamicin and sulbactam.
J Antimicrob Chemother
; 77(6): 1676-1684, 2022 05 29.
Article
in English
| MEDLINE | ID: covidwho-1774396
ABSTRACT
BACKGROUND:
During the COVID-19 pandemic, the burden of nosocomial infections caused by MDR pathogens has caused a shortage of polymyxins. Thus, we evaluated the in vitro synergism and antibiofilm activity of antimicrobial combinations and propose a test kit for synergism against carbapenem-resistant Acinetobacter baumannii (CRAB).METHODS:
Fifty-six CRAB isolates were tested for synergy between meropenem, gentamicin and ampicillin/sulbactam. MICs were determined by broth microdilution. Synergism was tested using chequerboard analysis, followed by a time-kill curve. Additionally, minimum biofilm eradication concentration was determined and the antibiofilm activity of the combinations was evaluated by MTT assay and biomass reduction. A test kit was developed for routine laboratory testing to detect synergism.RESULTS:
All CRAB isolates were resistant to gentamicin and ampicillin/sulbactam. Chequerboard synergism occurred against 75% of the isolates. Meropenemâ+âampicillin/sulbactam was the most frequent combination with synergism (69%), followed by ampicillin/sulbactamâ+âgentamicin (64%) and meropenemâ+âgentamicin (51%). All combinations presented only bacteriostatic activity and no bactericidal or antibiofilm effects. The routine laboratory test showed 100% accuracy compared with other in vitro assays.CONCLUSIONS:
Our study demonstrates the potential role of antibiotic combinations against planktonic bacteria. In vitro synergism is possible and can be an alternative treatment for patients with CRAB infection during a polymyxin shortage.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Acinetobacter Infections
/
Acinetobacter baumannii
/
COVID-19
Type of study:
Experimental Studies
Limits:
Humans
Language:
English
Journal:
J Antimicrob Chemother
Year:
2022
Document Type:
Article
Affiliation country:
Jac
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