In vitro activity of ceftaroline, ceftazidime-avibactam, and comparators against Gram-positive and -negative organisms in China: the 2018 results from the ATLAS program.
Data on antibiotic resistance is essential to adapt treatment strategies against the rapidly changing reality of antimicrobial resistance.
To study the in vitro activity of ceftaroline, ceftazidime-avibactam, and comparators against Gram-positive and Gram-negative bacteria collected from China in the year 2018.
A total of 2301 clinical isolates were collected from 17 medical center laboratories in China, which participated in the ATLAS program in 2018. Antimicrobial susceptibilities were determined by the broth microdilution method at a central laboratory. Clinical and Laboratory Standards Institute (CLSI) breakpoints were used to interpret the results except for tigecycline, for which the US Food and Drug Administration (FDA) breakpoint were used.
The susceptibility rates of methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP), and β-hemolytic streptococcus to ceftaroline were 83.9%, 100%, and 100%, respectively. Escherichia coli, imipenem-susceptible (IMP-S) Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, IMP-S Enterobacter cloacae, Proteus mirabilis, Morganella morganii, Serratia marcescens and Pseudomonas aeruginosa had high susceptibility rates to ceftazidime-avibactam (95.8%, 100%, 97.7%, 94.5%, 100%, 90.2%, 96.0%, 97.5% and 90.7%, respectively). However, imipenem-resistant Escherichia coli and imipenem-resistant Pseudomonas aeruginosa demonstrated low susceptibility to ceftazidime-avibactam (33.3% and 75.8%, respectively). Against MRSA, methicillin-susceptible Staphylococcus aureus (MSSA), S. pneumoniae and β-hemolytic streptococci, the susceptibility rates of tigecycline were 93.5%, 99.2%, 100% and 100%, respectively. Levofloxacin also showed high in vitro activity against S. pneumoniae and β-hemolytic streptococci with a susceptibility rate of 100% and 98.4%. The susceptibility rate of E. faecalis to ampicillin was 100%. Among Gram-negative isolates, tigecycline and colistin showed good activity against E. coli, K. pneumoniae, imipenem-resistant E. cloacae, C. freundii and A. baumannii (susceptibility rates and intermediate susceptibility rates of 99.3% and 96.8%, 95.4% and 94.5%, 100% and 87.5%, 96.4% and 89.3%, MIC90 of 2 mg/L and 97.4%, respectively). E. coli and E. cloacae had high susceptibility rates to imipenem and meropenem (93.0% and 92.8%, 89.8% and 92.1%, respectively). M. morganii and P. mirabilis demonstrated meropenem and piperacillin-tazobactam susceptibility rates of 96.0% and 94.0%, 94.1% and 92.2%, respectively.
Ceftaroline showed good activity among tested antimicrobial agents against Gram-positive species, while ceftazidime-avibactam had good activity against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Proteus mirabilis, Morganella morganii, Serratia marcescens and Pseudomonas aeruginosa excluding carbapenem-resistant isolates.
Jia P
,Zhu Y
,Zhang H
,Cheng B
,Guo P
,Xu Y
,Yang Q
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《BMC MICROBIOLOGY》
In vitro activity of ceftazidime, ceftaroline and aztreonam alone and in combination with avibactam against European Gram-negative and Gram-positive clinical isolates.
Recent clinical isolates of key Gram-negative and Gram-positive bacteria were collected in 2012 from hospitalised patients in medical centres in four European countries (France, Germany, Italy and Spain) and were tested using standard broth microdilution methodology to assess the impact of 4 mg/L avibactam on the in vitro activities of ceftazidime, ceftaroline and aztreonam. Against Enterobacteriaceae, addition of avibactam significantly enhanced the level of activity of these antimicrobials. MIC(90) values (minimum inhibitory concentration that inhibits 90% of the isolates) of ceftazidime, ceftaroline and aztreonam for Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Enterobacter aerogenes, Citrobacter freundii and Morganella morganii were reduced up to 128-fold or greater when combined with avibactam. A two-fold reduction in the MIC(90) of ceftazidime to 8 mg/L was noted in Pseudomonas aeruginosa isolates when combined with avibactam, whereas little effect of avibactam was noted on the MIC values of the test compounds when tested against Acinetobacter baumannii isolates. Avibactam had little effect on the excellent activity of ceftazidime, ceftaroline and aztreonam against Haemophilus influenzae. It had no impact on the in vitro activity of ceftazidime and ceftaroline against staphylococci and streptococci. This study demonstrates that addition of avibactam enhances the activities of ceftazidime, ceftaroline and aztreonam against Enterobacteriaceae and P. aeruginosa but not against A. baumannii.
Testa R
,Cantón R
,Giani T
,Morosini MI
,Nichols WW
,Seifert H
,Stefanik D
,Rossolini GM
,Nordmann P
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