Abstract
Acinetobacter baumannii is an important cause of nosocomial infection with increasing carbapenem resistance. The aim of this study was to compare the efficacy of colistin + rifampicin and imipenem + rifampicin combinations with that of several other antibiotic regimens against carbapenem-resistant A. baumannii pneumonia using an immunosuppressed mouse model. Three different A. baumannii strains with diverse resistance mechanisms (OXA-51-, IMP-1- and VIM-2-type β-lactamases) were used. Among the monotherapy regimens, only rifampicin significantly reduced the bacterial load in lungs 24 h after infection with the OXA-51-producing strain. Addition of rifampicin to either imipenem or colistin yielded synergistic results after 48 h. Rifampicin was bactericidal against the IMP-1-producing strain, and only the imipenem + rifampicin combination yielded synergistic effects. In contrast, rifampicin alone was not effective against the VIM-2-producing strain, but the imipenem + rifampicin combination was bacteriostatic even at 24 h post-infection. Tigecycline and amikacin were not effective against any of the three strains. Rifampicin-based combinations were effective against A. baumannii bacteraemia and improved survival regardless of the strain type. Contrary to the similar minimum inhibitory concentration results, the antibacterial effects of rifampicin were quite different according to the strains; a tailored antibiotic strategy must be considered in treatment. Addition of rifampicin to either imipenem or colistin would be effective.
| Original language | English |
|---|---|
| Pages (from-to) | 33-39 |
| Number of pages | 7 |
| Journal | International Journal of Antimicrobial Agents |
| Volume | 33 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2009 Jan 1 |
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Keywords
- Acinetobacter baumannii
- Colistin
- In vivo
- Pneumonia
- Rifampicin
ASJC Scopus subject areas
- Microbiology (medical)
- Infectious Diseases
- Pharmacology (medical)
Cite this
Efficacy of monotherapy and combined antibiotic therapy for carbapenem-resistant Acinetobacter baumannii pneumonia in an immunosuppressed mouse model. / Song, Joon-Young; Cheong, Hee-Jin; Lee, Jacob; Sung, Ah Kyeong; Kim, Woo Joo.
In: International Journal of Antimicrobial Agents, Vol. 33, No. 1, 01.01.2009, p. 33-39.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Efficacy of monotherapy and combined antibiotic therapy for carbapenem-resistant Acinetobacter baumannii pneumonia in an immunosuppressed mouse model
AU - Song, Joon-Young
AU - Cheong, Hee-Jin
AU - Lee, Jacob
AU - Sung, Ah Kyeong
AU - Kim, Woo Joo
PY - 2009/1/1
Y1 - 2009/1/1
N2 - Acinetobacter baumannii is an important cause of nosocomial infection with increasing carbapenem resistance. The aim of this study was to compare the efficacy of colistin + rifampicin and imipenem + rifampicin combinations with that of several other antibiotic regimens against carbapenem-resistant A. baumannii pneumonia using an immunosuppressed mouse model. Three different A. baumannii strains with diverse resistance mechanisms (OXA-51-, IMP-1- and VIM-2-type β-lactamases) were used. Among the monotherapy regimens, only rifampicin significantly reduced the bacterial load in lungs 24 h after infection with the OXA-51-producing strain. Addition of rifampicin to either imipenem or colistin yielded synergistic results after 48 h. Rifampicin was bactericidal against the IMP-1-producing strain, and only the imipenem + rifampicin combination yielded synergistic effects. In contrast, rifampicin alone was not effective against the VIM-2-producing strain, but the imipenem + rifampicin combination was bacteriostatic even at 24 h post-infection. Tigecycline and amikacin were not effective against any of the three strains. Rifampicin-based combinations were effective against A. baumannii bacteraemia and improved survival regardless of the strain type. Contrary to the similar minimum inhibitory concentration results, the antibacterial effects of rifampicin were quite different according to the strains; a tailored antibiotic strategy must be considered in treatment. Addition of rifampicin to either imipenem or colistin would be effective.
AB - Acinetobacter baumannii is an important cause of nosocomial infection with increasing carbapenem resistance. The aim of this study was to compare the efficacy of colistin + rifampicin and imipenem + rifampicin combinations with that of several other antibiotic regimens against carbapenem-resistant A. baumannii pneumonia using an immunosuppressed mouse model. Three different A. baumannii strains with diverse resistance mechanisms (OXA-51-, IMP-1- and VIM-2-type β-lactamases) were used. Among the monotherapy regimens, only rifampicin significantly reduced the bacterial load in lungs 24 h after infection with the OXA-51-producing strain. Addition of rifampicin to either imipenem or colistin yielded synergistic results after 48 h. Rifampicin was bactericidal against the IMP-1-producing strain, and only the imipenem + rifampicin combination yielded synergistic effects. In contrast, rifampicin alone was not effective against the VIM-2-producing strain, but the imipenem + rifampicin combination was bacteriostatic even at 24 h post-infection. Tigecycline and amikacin were not effective against any of the three strains. Rifampicin-based combinations were effective against A. baumannii bacteraemia and improved survival regardless of the strain type. Contrary to the similar minimum inhibitory concentration results, the antibacterial effects of rifampicin were quite different according to the strains; a tailored antibiotic strategy must be considered in treatment. Addition of rifampicin to either imipenem or colistin would be effective.
KW - Acinetobacter baumannii
KW - Colistin
KW - In vivo
KW - Pneumonia
KW - Rifampicin
UR - http://www.scopus.com/inward/record.url?scp=59349103552&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=59349103552&partnerID=8YFLogxK
U2 - 10.1016/j.ijantimicag.2008.07.008
DO - 10.1016/j.ijantimicag.2008.07.008
M3 - Article
C2 - 18835761
AN - SCOPUS:59349103552
VL - 33
SP - 33
EP - 39
JO - International Journal of Antimicrobial Agents
JF - International Journal of Antimicrobial Agents
SN - 0924-8579
IS - 1
ER -