Efficacy of ceftazidime/avibactam in various combinations for the treatment of experimental osteomyelitis in rabbits caused by OXA-48-/ESBL-producing Escherichia coli.
Journal
The Journal of antimicrobial chemotherapy
ISSN: 1460-2091
Titre abrégé: J Antimicrob Chemother
Pays: England
ID NLM: 7513617
Informations de publication
Date de publication:
03 05 2023
03 05 2023
Historique:
received:
23
12
2022
accepted:
23
02
2023
medline:
4
5
2023
pubmed:
11
3
2023
entrez:
10
3
2023
Statut:
ppublish
Résumé
While the treatment of ESBL-producing Enterobacterales osteomyelitis relies on carbapenems, the optimal regimen for OXA48 types remains unclear. We evaluated the efficacy of ceftazidime/avibactam in different combinations in an experimental model of OXA-48-/ESBL-producing Escherichia coli osteomyelitis. E. coli pACYC184 is a clinical strain harbouring blaOXA-48 and blaCTX-M-15 inserts, with 'increased exposure susceptibility' to imipenem (MIC, 2 mg/L), gentamicin (MIC, 0.5 mg/L), colistin (MIC, 0.25 mg/L), ceftazidime/avibactam (MIC, 0.094 mg/L) and fosfomycin (MIC, 1 mg/L), and resistance to ceftazidime (MIC, 16 mg/L). Osteomyelitis was induced in rabbits by tibial injection of 2 × 108 cfu of OXA-48/ESBL E. coli. Treatment started 14 days later for 7 days in six groups: (1) control, (2) colistin 150.000 IU/kg subcutaneously (SC) q8h, (3) ceftazidime/avibactam 100/25 mg/kg SC q8h, (4) ceftazidime/avibactam + colistin, (5) ceftazidime/avibactam + fosfomycin 150 mg/kg SC q12h, (6) ceftazidime/avibactam + gentamicin 15 mg/kg intramuscularly (IM) q24h. Treatment was evaluated at Day 24 according to bone cultures. In vitro, time-kill curves of ceftazidime/avibactam in combination showed a synergistic effect. In vivo, compared with controls, rabbits treated with colistin alone had similar bone bacterial density (P = 0.50), whereas ceftazidime/avibactam alone or in combinations significantly decreased bone bacterial densities (P = 0.004 and P < 0.0002, respectively). Bone sterilization was achieved using ceftazidime/avibactam in combination with colistin (91%) or fosfomycin (100%) or gentamicin (100%) (P < 0.0001), whereas single therapies were not different from controls. No ceftazidime/avibactam-resistant strains emerged in rabbits treated, regardless of the combination. In our model of E. coli OXA-48/ESBL osteomyelitis, ceftazidime/avibactam in combination was more effective than any single therapy, whatever the companion drug used (gentamicin or colistin or fosfomycin).
Sections du résumé
BACKGROUND
While the treatment of ESBL-producing Enterobacterales osteomyelitis relies on carbapenems, the optimal regimen for OXA48 types remains unclear. We evaluated the efficacy of ceftazidime/avibactam in different combinations in an experimental model of OXA-48-/ESBL-producing Escherichia coli osteomyelitis.
METHODS
E. coli pACYC184 is a clinical strain harbouring blaOXA-48 and blaCTX-M-15 inserts, with 'increased exposure susceptibility' to imipenem (MIC, 2 mg/L), gentamicin (MIC, 0.5 mg/L), colistin (MIC, 0.25 mg/L), ceftazidime/avibactam (MIC, 0.094 mg/L) and fosfomycin (MIC, 1 mg/L), and resistance to ceftazidime (MIC, 16 mg/L). Osteomyelitis was induced in rabbits by tibial injection of 2 × 108 cfu of OXA-48/ESBL E. coli. Treatment started 14 days later for 7 days in six groups: (1) control, (2) colistin 150.000 IU/kg subcutaneously (SC) q8h, (3) ceftazidime/avibactam 100/25 mg/kg SC q8h, (4) ceftazidime/avibactam + colistin, (5) ceftazidime/avibactam + fosfomycin 150 mg/kg SC q12h, (6) ceftazidime/avibactam + gentamicin 15 mg/kg intramuscularly (IM) q24h. Treatment was evaluated at Day 24 according to bone cultures.
RESULTS
In vitro, time-kill curves of ceftazidime/avibactam in combination showed a synergistic effect. In vivo, compared with controls, rabbits treated with colistin alone had similar bone bacterial density (P = 0.50), whereas ceftazidime/avibactam alone or in combinations significantly decreased bone bacterial densities (P = 0.004 and P < 0.0002, respectively). Bone sterilization was achieved using ceftazidime/avibactam in combination with colistin (91%) or fosfomycin (100%) or gentamicin (100%) (P < 0.0001), whereas single therapies were not different from controls. No ceftazidime/avibactam-resistant strains emerged in rabbits treated, regardless of the combination.
CONCLUSIONS
In our model of E. coli OXA-48/ESBL osteomyelitis, ceftazidime/avibactam in combination was more effective than any single therapy, whatever the companion drug used (gentamicin or colistin or fosfomycin).
Identifiants
pubmed: 36897329
pii: 7075680
doi: 10.1093/jac/dkad070
doi:
Substances chimiques
Anti-Bacterial Agents
0
avibactam
7352665165
Fosfomycin
2N81MY12TE
Colistin
Z67X93HJG1
beta-Lactamases
EC 3.5.2.6
Azabicyclo Compounds
0
Drug Combinations
0
Gentamicins
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
1211-1218Informations de copyright
© The Author(s) 2023. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.