TABLE 2

Activities of RX-P873 and comparator antimicrobial agents when tested against 657 Enterobacteriaceae and 402 nonfermentative bacilli

Organism group (no. tested) and antimicrobial agentMIC (μg/ml)Susceptible/intermediate/resistant (%) according to:
MIC50MIC90RangeCLSIaEUCASTa
Enterobacteriaceae (657)b
    RX-P8730.250.50.06–>32
    Piperacillin-tazobactam232≤0.5–>6487.5/6.3/6.283.9/3.6/12.5
    Ceftriaxone0.06>2≤0.015–>279.6/0.3/20.179.6/0.3/20.1
    Ceftazidime0.25>16≤0.12–>1682.3/1.9/15.879.3/3.0/17.7
    Cefepime≤0.128≤0.12–>1687.1/3.9/9.085.5/4.1/10.4
    Ciprofloxacin0.03>8≤0.004–>883.1/2.0/14.981.6/1.5/16.9
    Colistin0.5>8≤0.12–>883.3/0.0/16.7
    Gentamicin0.52≤0.06–>892.4/0.3/7.391.0/1.4/7.6
    Meropenem≤0.06≤0.06≤0.06–>898.0/0.2/1.898.2/0.1/1.7
    Tigecyclinec0.520.06–>497.1/2.6/0.388.9/8.2/2.9
E. coli (202)
    RX-P8730.120.250.06–2
    Piperacillin-tazobactam28≤0.5–>6493.1/3.4/3.590.6/2.5/6.9
    Ceftriaxone0.06>2≤0.015–>288.6/0.0/11.488.6/0.0/11.4
    Ceftazidime0.252≤0.12–>1693.1/1.0/5.989.1/4.0/6.9
    Cefepime≤0.122≤0.12–>1691.1/1.5/7.489.1/3.0/7.9
    Ciprofloxacin0.015>80.008–>878.2/1.0/20.877.7/0.5/21.8
    Colistin0.250.50.25–0.5100.0/0.0/0.0
    Gentamicin0.51≤0.06–>893.1/0.5/6.492.1/1.0/6.9
    Meropenem≤0.06≤0.06≤0.06100.0/0.0/0.0100.0/0.0/0.0
    Tigecyclinec0.120.250.06–1100.0/0.0/0.0100.0/0.0/0.0
K. pneumoniae (202)
    RX-P8730.250.50.12–2
    Piperacillin-tazobactam232≤0.5–>6488.1/3.0/8.983.7/4.4/11.9
    Ceftriaxone0.06>2≤0.015–>277.7/0.0/22.377.7/0.0/22.3
    Ceftazidime0.25>16≤0.12–>1676.7/3.5/19.875.2/1.5/23.3
    Cefepime≤0.12>16≤0.12–>1679.2/4.0/16.878.7/2.5/18.8
    Ciprofloxacin0.03>80.008–>880.2/2.5/17.379.7/0.5/19.8
    Colistin0.510.25–>897.5/0.0/2.5
    Gentamicin0.25>8≤0.06–>889.1/0.0/10.987.6/1.5/10.9
    Meropenem≤0.06≤0.06≤0.06–>895.1/0.1/5.095.1/0.4/4.5
    Tigecyclinec0.520.12–496.5/3.5/0.088.6/7.9/3.5
E. cloacae (50)
    RX-P8730.50.50.12–1
    Piperacillin-tazobactam4>641–>6470.0/12.0/18.064.0/6.0/30.0
    Ceftriaxone1>20.03–>254.0/0.0/46.054.0/0.0/46.0
    Ceftazidime0.5>16≤0.12–>1660.0/2.0/38.054.0/6.0/40.0
    Cefepime≤0.128≤0.12–>1676.0/16.0/8.072.0/14.0/14.0
    Ciprofloxacin0.01580.008–>880.0/6.0/14.080.0/0.0/20.0
    Colistin0.580.25–>888.0/0.0/12.0
    Gentamicin0.25>80.12–>888.0/0.0/12.084.0/4.0/12.0
    Meropenem≤0.060.12≤0.06–298.0/2.0/0.0100.0/0.0/0.0
    Tigecyclinec0.520.25–>490.0/8.0/2.084.0/6.0/10.0
E. aerogenes (50)
    RX-P8730.250.50.12–1
    Piperacillin-tazobactam464≤0.5–>6464.0/32.0/4.056.0/8.0/36.0
    Ceftriaxone0.25>2≤0.015–>254.0/0.0/46.054.0/0.0/46.0
    Ceftazidime1>16≤0.12–>1654.0/2.0/44.052.0/2.0/46.0
    Cefepime≤0.122≤0.12–1692.0/6.0/2.088.0/10.0/2.0
    Ciprofloxacin0.0150.50.008–>894.0/0.0/6.090.0/4.0/6.0
    Colistin0.250.50.25–>896.0/0.0/4.0
    Gentamicin0.2510.12–>896.0/0.0/4.096.0/0.0/4.0
    Meropenem≤0.060.12≤0.06–0.25100.0/0.0/0.0100.0/0.0/0.0
    Tigecyclinec0.510.12–498.0/2.0/0.092.0/6.0/2.0
C. freundii (51)
    RX-P8730.250.50.12–2
    Piperacillin-tazobactam264≤0.5–>6482.4/7.8/9.878.4/4.0/17.6
    Ceftriaxone0.25>20.06–>276.5/0.0/23.576.5/0.0/23.5
    Ceftazidime0.5>160.25–>1678.4/0.0/21.672.5/5.9/21.6
    Cefepime≤0.124≤0.12–>1688.2/4.0/7.886.3/5.9/7.8
    Ciprofloxacin0.0620.008–>886.3/3.9/9.880.4/5.9/13.7
    Colistin0.51≤0.12–1100.0/0.0/0.0
    Gentamicin0.510.12–>892.2/1.9/5.990.2/2.0/7.8
    Meropenem≤0.06≤0.06≤0.06–>896.1/0.0/3.996.1/0.0/3.9
    Tigecyclinec0.2510.12–2100.0/0.0/0.092.2/7.8/0.0
Proteus spp. (51)d
    RX-P873120.12–>32
    Piperacillin-tazobactam≤0.5≤0.5≤0.5–4100.0/0.0/0.0100.0/0.0/0.0
    Ceftriaxone≤0.0150.06≤0.015–>296.1/0.0/3.996.1/0.0/3.9
    Ceftazidime≤0.12≤0.12≤0.12–898.0/2.0/0.096.1/1.9/2.0
    Cefepime≤0.12≤0.12≤0.12–896.1/3.9/0.096.1/1.9/2.0
    Ciprofloxacin0.032≤0.004–>888.2/2.0/9.886.3/1.9/11.8
    Colistin>8>8>80.0/0.0/100.0
    Gentamicin0.520.12–>898.0/0.0/2.096.1/1.9/2.0
    Meropenem≤0.060.12≤0.06–0.12100.0/0.0/0.0100.0/0.0/0.0
    Tigecyclinec120.12–>492.2/5.8/2.052.9/39.3/7.8
Serratia marcescens (51)
    RX-P8730.50.50.12–2
    Piperacillin-tazobactam28≤0.5–6496.1/3.9/0.094.1/2.0/3.9
    Ceftriaxone0.2520.03–>288.2/4.0/7.888.2/4.0/7.8
    Ceftazidime0.250.5≤0.12–4100.0/0.0/0.098.0/2.0/0.0
    Cefepime≤0.120.25≤0.12–>1698.0/0.0/2.098.0/0.0/2.0
    Ciprofloxacin0.060.120.015–>898.0/0.0/2.094.1/3.9/2.0
    Colistin>8>81–>89.8/0.0/90.2
    Gentamicin0.510.12–>898.0/0.0/2.098.0/0.0/2.0
    Meropenem≤0.060.12≤0.06–0.25100.0/0.0/0.0100.0/0.0/0.0
    Tigecyclinec120.5–496.1/3.9/0.080.4/15.7/3.9
P. aeruginosa (200)
    RX-P873240.25–8
    Piperacillin-tazobactam464≤0.5–>6480.5/11.0/8.580.5/0.0/19.5
    Ceftazidime2>160.5–>1683.0/4.0/13.083.0/0.0/17.0
    Cefepime2160.25–>1684.5/10.5/5.084.5/0.0/15.5
    Ciprofloxacin0.12>80.008–>878.0/2.0/20.076.0/2.0/22.0
    Tobramycin0.52≤0.25–>1691.0/1.5/7.591.0/0.0/9.0
    Amikacin48≤0.25–>3293.5/2.0/4.591.0/2.5/6.5
    Meropenem0.58≤0.06–>876.0/6.0/18.076.0/14.5/9.5
    Colistin120.25–499.5/0.5/0.0100.0/0.0/0.0
Acinetobacter baumannii (202)
    RX-P8730.510.12–4
    Ampicillin-sulbactam16>320.5–>3248.0/11.4/40.6
    Ceftazidime>16>160.5–>1638.1/2.5/59.4
    Cefepime16>160.25–>1636.6/13.4/50.0
    Ciprofloxacin>8>80.06–>836.1/0.0/63.936.1/0.0/63.9
    Tobramycin4>16≤0.25–>1653.5/3.4/43.153.5/0.0/46.5
    Amikacin8>32≤0.25–>3258.4/6.0/35.653.5/4.9/41.6
    Meropenem>8>8≤0.06–>846.0/1.5/52.545.5/2.0/52.5
    Colistin120.25–>897.0/0.0/3.097.0/0.0/3.0
    Tigecycline140.12–>4
  • a 2013 CLSI and EUCAST criteria.

  • b Includes Citrobacter freundii (51 strains), Enterobacter aerogenes (50 strains), Enterobacter cloacae (50 strains), Escherichia coli (202 strains), Klebsiella pneumoniae (202 strains), Morganella morganii (11 strains), Proteus mirabilis (30 strains), Proteus vulgaris (4 strains), Providencia rettgeri (4 strains), Providencia stuartii (2 strains), and Serratia marcescens (51 strains).

  • c In the absence of a CLSI breakpoint, U.S. FDA breakpoints were applied when available (22).

  • d Includes Morganella morganii (11 strains), Proteus mirabilis (30 strains), Proteus vulgaris (4 strains), Providencia rettgeri (4 strains), and Providencia stuartii (4 strains).