Table 4

Activities of BC-3781 and comparator antimicrobial agents against bacterial pathogens causing predominantly respiratory tract infections

Organism (no. tested) and antimicrobial agentMIC50 (μg/ml)MIC90 (μg/ml)Range (μg/ml)CLSI %S/%RaEUCAST %S/%Ra
S. pneumoniae (1,473)
    BC-37810.120.25≤0.008–1
    Azithromycin≤0.25>4≤0.25–>462.6/36.661.7/37.4
    Ceftriaxone≤0.061≤0.06–891.3/1.278.0/1.2
    Cefuroxime≤0.128≤0.12–>1673.3/24.072.0/26.7
    Clarithromycin≤0.25>32≤0.25–>3263.2/36.663.2/36.6
    Doxycycline0.258≤0.06–>873.9/25.2
    Erythromycin≤0.25>4≤0.25–>462.8/36.262.8/36.2
    Imipenem≤0.120.5≤0.12–179.6/4.4100.0/0.0
    Levofloxacin11≤0.5–>498.9/1.098.9/1.1
    Linezolid11≤0.12–499.9/−100.0/0.0
    Moxifloxacin≤0.5≤0.5≤0.5–>499.0/0.798.7/1.3
    Penicillinb≤0.034≤0.03–>488.5/0.5
    Penicillinc≤0.034≤0.03–>461.3/21.261.3/11.5
    Tigecyclined≤0.030.06≤0.03–0.599.7/−
    Trimethoprim-sulfamethoxazole≤0.5>4≤0.5–>468.3/23.274.0/23.2
    Vancomycin0.250.5≤0.12–1100.0/−100.0/0.0
H. influenzae (360)
    BC-3781120.015–8
    Ampicillin≤1>8≤1–>874.4/23.374.4/25.6
    Azithromycin12≤0.25–>498.3/−0.8e/1.7
    Ceftriaxone≤0.06≤0.06≤0.06–0.5100.0/−99.2/0.8
    Cefuroxime12≤0.12–>1698.6/0.674.4/7.5
    Ciprofloxacin≤0.03≤0.03≤0.03–1100.0/−99.7/0.3
    Clarithromycin816≤0.25–>3281.3/2.50.3/1.1
    Doxycycline0.50.50.12–298.9/0.0
    Erythromycin480.25–>80.3/2.8
    Imipenem0.51≤0.12–4100.0/−99.7/0.3
    Moxifloxacin≤0.5≤0.5≤0.5–1100.0/−99.7/0.3
    Tigecyclined0.250.250.06–190.6/−
    Trimethoprim-sulfamethoxazole≤0.5>4≤0.5–>468.1/29.468.1/31.7
M. catarrhalis (253)
    BC-37810.120.25≤0.008–0.5
    Azithromycin≤0.25≤0.25≤0.25–299.6/−99.6/0.4
    Ceftriaxone0.250.5≤0.06–1100.0/−100.0/0.0
    Cefuroxime12≤0.12–899.6/0.072.3/1.6
    Ciprofloxacin≤0.03≤0.03≤0.03–0.5100.0/−100.0/0.0
    Clarithromycin≤0.25≤0.25≤0.25–499.6/−98.7/0.4
    Doxycycline0.120.25≤0.06–499.6/0.4
    Erythromycin0.250.25≤0.06–499.6/−93.5/0.4
    Imipenem≤0.12≤0.12≤0.12–0.25100.0/0.0
    Moxifloxacin≤0.5≤0.5≤0.5100.0/0.0
    Penicillin>4>4≤0.03–>4
    Tigecyclined0.060.25≤0.03–0.5
    Trimethoprim-sulfamethoxazole≤0.5≤0.5≤0.5–>494.5/2.094.5/3.2
  • a %S, percentage of susceptible organisms; %R, percentage of resistant organisms. Criteria were as published by the CLSI (2012) and EUCAST (2011) (25, 26).

  • b Criteria as published by the CLSI (2012) for “Penicillin parenteral (non-meningitis)” (25).

  • c Criteria as published by the CLSI (2012) for “Penicillin (oral penicillin V)” (25).

  • d U.S. FDA breakpoints were applied (Tygacil drug information) (27).

  • e Percentage inhibited at ≤0.25 μg/ml (26).