Journal: Antimicrobial Agents and Chemotherapy

Article Title: In Vitro and In Vivo Activities of DS-2969b, a Novel GyrB Inhibitor, and Its Water-Soluble Prodrug, DS11960558, against Methicillin-Resistant Staphylococcus aureus

doi: 10.1128/AAC.02556-17

Figure Lengend Snippet: Antibacterial activities of DS-2969b and linezolid against aerobic bacteria

Article Snippet: DS-2969b and LZD showed time-dependent slow killing with exposures at 1×, 4×, and 16× MIC. table ft1 table-wrap mode="anchored" t5 TABLE 2 caption a7 Strain MIC (μg/ml) DS-2969b Linezolid Staphylococcus aureus ATCC 6538P 0.25 2 Staphylococcus epidermidis ATCC 14990 0.5 1 Streptococcus pneumoniae ATCC 49619 0.25 1 Streptococcus pyogenes ATCC 12344 ≤0.125 1 Enterococcus faecalis ATCC 29212 0.25 2 Enterococcus faecium ATCC 19434 2 4 Moraxella catarrhalis ATCC 25238 0.25 8 Haemophilus influenzae ATCC 49247 0.5 8 Klebsiella pneumoniae ATCC 13883 64 >128 Enterobacter cloacae ATCC 13047 >128 >128 Serratia marcescens ATCC 13880 32 >128 Proteus vulgaris ATCC 13315 16 16 Pseudomonas aeruginosa ATCC 15692 128 >128 Stenotrophomonas maltophilia ATCC 13637 64 >128 Acinetobacter baumannii ATCC 19606 64 >128 Open in a separate window Antibacterial activities of DS-2969b and linezolid against aerobic bacteria table ft1 table-wrap mode="anchored" t5 TABLE 3 caption a7 Compound MIC (μg/ml) Range 50% 90% DS-2969b 0.03–0.5 0.125 0.25 Linezolid 0.5–2 1 2 Vancomycin 0.03–2 1 2 Levofloxacin 8–32 32 32 Open in a separate window a A total of 67 isolates were tested.

Techniques:

Journal: Antimicrobial Agents and Chemotherapy

Article Title: Spheroplast-Mediated Carbapenem Tolerance in Gram-Negative Pathogens

doi: 10.1128/AAC.00756-19

Figure Lengend Snippet: Bacterial isolates evaluated in this study a

Article Snippet: Our results suggest that measurement of antibiotic susceptibility and, ultimately, treatment outcome could include more-nuanced responses, such as tolerance, in Gram-negative pathogens. table ft1 table-wrap mode="anchored" t5 TABLE 1 caption a7 Isolate Carbapenemase Specimen source MHA MIC value (μg/ml) MHA MIC value interpretation e BHI + agar MIC value (μg/ml) BHI + agar MIC value interpretation f E. cloacae complex ARB0008 b NA NA 1 SUS 1.5 NA E. cloacae complex ATCC 13047 NA NA 0.064 SUS 0.094 NA E. cloacae complex WCM0001 NA Blood 0.023 SUS 0.023 NA E. coli WCM0001 NA Urine 0.016 SUS 0.016 NA E. coli TUV93-0 NA NA 0.023 SUS 0.023 NA K. aerogenes ARB0007 NA NA 0.064 SUS 0.047 NA K. aerogenes WCM0001 NA Respiratory/sinus 0.032 SUS 0.032 NA K. pneumoniae WCM0001 NA Blood 0.047 SUS 0.032 NA K. pneumoniae WCM0002 NA Respiratory/sinus 0.032 SUS 0.064 NA P. aeruginosa PA14 NA NA 0.25 SUS 0.25 NA V. cholerae N16961 NA NA 0.125 SUS 0.125 NA E. cloacae complex 41952 KPC NA >32 RES >32 NA E. coli 52862 KPC NA >32 RES 32 NA K. aerogenes 28944 KPC NA >32 RES >32 NA K. pneumoniae ARB0120 c KPC NA 16 RES 16 NA P. aeruginosa ARB0090 d KPC NA >32 RES >32 NA Open in a separate window a ARB, Centers for Disease Control and Prevention and U.S. Food and Drug Administration Antibiotic Resistance Isolate Bank; ATCC, American Type Culture Collection; BHI + , brain heart infusion agar with supplements; MHA, Mueller-Hinton agar; NA, not applicable; RES, resistant; SUS, susceptible; WCM, Weill Cornell Medicine. b For ARB0008, the meropenem MIC value determined by the ARB is 2 μg/ml (intermediate).

Techniques:

Journal: Antimicrobial Agents and Chemotherapy

Article Title: Spheroplast-Mediated Carbapenem Tolerance in Gram-Negative Pathogens

doi: 10.1128/AAC.00756-19

Figure Lengend Snippet: Meropenem-induced spheroplasts can recover to form an exponentially growing population. A time-lapse montage of spheroplasts imaged upon removal of meropenem after 6 h of treatment is shown. The antibiotic was removed by addition of purified NDM-1 carbapenemase, followed by time-lapse microscopy on BHI+ agarose pads (0.8% [wt/vol] agarose). Images were then acquired 5 min apart for another 2 h. Both E. coli isolates were omitted since no spheroplasts were observed after 6 h of meropenem treatment. Scale bars, 5 μm.

Article Snippet: Our results suggest that measurement of antibiotic susceptibility and, ultimately, treatment outcome could include more-nuanced responses, such as tolerance, in Gram-negative pathogens. table ft1 table-wrap mode="anchored" t5 TABLE 1 caption a7 Isolate Carbapenemase Specimen source MHA MIC value (μg/ml) MHA MIC value interpretation e BHI + agar MIC value (μg/ml) BHI + agar MIC value interpretation f E. cloacae complex ARB0008 b NA NA 1 SUS 1.5 NA E. cloacae complex ATCC 13047 NA NA 0.064 SUS 0.094 NA E. cloacae complex WCM0001 NA Blood 0.023 SUS 0.023 NA E. coli WCM0001 NA Urine 0.016 SUS 0.016 NA E. coli TUV93-0 NA NA 0.023 SUS 0.023 NA K. aerogenes ARB0007 NA NA 0.064 SUS 0.047 NA K. aerogenes WCM0001 NA Respiratory/sinus 0.032 SUS 0.032 NA K. pneumoniae WCM0001 NA Blood 0.047 SUS 0.032 NA K. pneumoniae WCM0002 NA Respiratory/sinus 0.032 SUS 0.064 NA P. aeruginosa PA14 NA NA 0.25 SUS 0.25 NA V. cholerae N16961 NA NA 0.125 SUS 0.125 NA E. cloacae complex 41952 KPC NA >32 RES >32 NA E. coli 52862 KPC NA >32 RES 32 NA K. aerogenes 28944 KPC NA >32 RES >32 NA K. pneumoniae ARB0120 c KPC NA 16 RES 16 NA P. aeruginosa ARB0090 d KPC NA >32 RES >32 NA Open in a separate window a ARB, Centers for Disease Control and Prevention and U.S. Food and Drug Administration Antibiotic Resistance Isolate Bank; ATCC, American Type Culture Collection; BHI + , brain heart infusion agar with supplements; MHA, Mueller-Hinton agar; NA, not applicable; RES, resistant; SUS, susceptible; WCM, Weill Cornell Medicine. b For ARB0008, the meropenem MIC value determined by the ARB is 2 μg/ml (intermediate).

Techniques: Purification, Time-lapse Microscopy

Journal: Antimicrobial Agents and Chemotherapy

Article Title: Spheroplast-Mediated Carbapenem Tolerance in Gram-Negative Pathogens

doi: 10.1128/AAC.00756-19

Figure Lengend Snippet: Spheroplast formation and recovery in human serum. (A and B) The indicated isolates were grown overnight in serum growth medium (SGM), diluted 1:10 (final volume, 500 μl) into fresh SGM, and incubated in the presence (A) or absence (B) of 10 μg/ml meropenem. Cells were plated (CFU per milliliter) at the indicated time points. (C) After 6 h of incubation, purified NDM-1 carbapenemase was added to remove meropenem, followed by time-lapse microscopy on agarose pads containing 40% (vol/vol) human serum. All values represent means of results from three biological replicates; error bars represent standard errors of the means. The red circle indicates the initial growth steps of a recovering spheroplast within cell debris.

Article Snippet: Our results suggest that measurement of antibiotic susceptibility and, ultimately, treatment outcome could include more-nuanced responses, such as tolerance, in Gram-negative pathogens. table ft1 table-wrap mode="anchored" t5 TABLE 1 caption a7 Isolate Carbapenemase Specimen source MHA MIC value (μg/ml) MHA MIC value interpretation e BHI + agar MIC value (μg/ml) BHI + agar MIC value interpretation f E. cloacae complex ARB0008 b NA NA 1 SUS 1.5 NA E. cloacae complex ATCC 13047 NA NA 0.064 SUS 0.094 NA E. cloacae complex WCM0001 NA Blood 0.023 SUS 0.023 NA E. coli WCM0001 NA Urine 0.016 SUS 0.016 NA E. coli TUV93-0 NA NA 0.023 SUS 0.023 NA K. aerogenes ARB0007 NA NA 0.064 SUS 0.047 NA K. aerogenes WCM0001 NA Respiratory/sinus 0.032 SUS 0.032 NA K. pneumoniae WCM0001 NA Blood 0.047 SUS 0.032 NA K. pneumoniae WCM0002 NA Respiratory/sinus 0.032 SUS 0.064 NA P. aeruginosa PA14 NA NA 0.25 SUS 0.25 NA V. cholerae N16961 NA NA 0.125 SUS 0.125 NA E. cloacae complex 41952 KPC NA >32 RES >32 NA E. coli 52862 KPC NA >32 RES 32 NA K. aerogenes 28944 KPC NA >32 RES >32 NA K. pneumoniae ARB0120 c KPC NA 16 RES 16 NA P. aeruginosa ARB0090 d KPC NA >32 RES >32 NA Open in a separate window a ARB, Centers for Disease Control and Prevention and U.S. Food and Drug Administration Antibiotic Resistance Isolate Bank; ATCC, American Type Culture Collection; BHI + , brain heart infusion agar with supplements; MHA, Mueller-Hinton agar; NA, not applicable; RES, resistant; SUS, susceptible; WCM, Weill Cornell Medicine. b For ARB0008, the meropenem MIC value determined by the ARB is 2 μg/ml (intermediate).

Techniques: Incubation, Purification, Time-lapse Microscopy