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 ... -  《BMC MICROBIOLOGY》

In vitro activity of ceftaroline-avibactam against gram-negative and gram-positive pathogens isolated from patients in Canadian hospitals from 2010 to 2012: results from the CANWARD surveillance study.

Karlowsky JA ，Adam HJ ，Baxter MR ，Lagacé-Wiens PR ，Walkty AJ ，Hoban DJ ，Zhanel GG ... -  《-》

Antimicrobial activity of ceftazidime-avibactam against Gram-negative organisms collected from U.S. medical centers in 2012.

Sader HS ，Castanheira M ，Flamm RK ，Farrell DJ ，Jones RN ... -  《-》

In vitro activity of avibactam (NXL104) in combination with β-lactams against Gram-negative bacteria, including OXA-48 β-lactamase-producing Klebsiella pneumoniae.

The objective of this study was to investigate the in vitro antibacterial activity of avibactam (formerly NXL104) in combination with imipenem, cefepime or ceftazidime against Gram-negative bacteria. Bacterial isolates included: Pseudomonas aeruginosa harbouring PER-1 β-lactamase (n=14); Acinetobacter baumannii harbouring PER-1, OXA-51 and OXA-58 (n=20); carbapenem-non-susceptible Klebsiella pneumoniae (n=25) and Escherichia coli (n=1) harbouring OXA-48; carbapenem-non-susceptible E. coli (n=1) harbouring both IMP-1 metallo-β-lactamase and extended-spectrum β-lactamase (ESBL); carbapenem-non-susceptible Serratia marcescens (n=1); and carbapenem-susceptible E. coli (n=20) and K. pneumoniae isolates (n=12) with CTX-M-15 ESBL. Minimum inhibitory concentrations (MICs) of imipenem, cefepime and ceftazidime were determined in combination with 4 mg/L avibactam by the Clinical and Laboratory Standards Institute (CLSI) method on Mueller-Hinton agar. Imipenem/avibactam and ceftazidime/avibactam displayed limited potency against A. baumannii isolates, whereas cefepime/avibactam and ceftazidime/avibactam were active against P. aeruginosa. Klebsiella pneumoniae isolates with OXA-48 β-lactamase were resistant to imipenem [MIC for 90% of the organisms (MIC(90)) ≥4 mg/L]. MIC(90) values for the combination of avibactam 4 mg/L with imipenem, cefepime and ceftazidime were in the susceptible range for all strains (MIC(90)≤0.5mg/L). All E. coli and K. pneumoniae isolates with CTX-M-15 β-lactamase were inhibited at ≤1 mg/L for combinations with avibactam and 100% were susceptible by CLSI breakpoint criteria to imipenem, cefepime and ceftazidime. In conclusion, combinations of imipenem, cefepime and ceftazidime with avibactam may present a promising therapeutic strategy to treat infections due to K. pneumoniae with OXA-48 enzyme as well as K. pneumoniae and E. coli with CTX-M-15 enzyme.

Aktaş Z ，Kayacan C ，Oncul O 《-》

The tigecycline evaluation and surveillance trial; assessment of the activity of tigecycline and other selected antibiotics against gram-positive and gram-negative pathogens from France collected between 2004 and 2016.

Decousser JW ，Woerther PL ，Soussy CJ ，Fines-Guyon M ，Dowzicky MJ ... -  《Antimicrobial Resistance and Infection Control》