Activities of aztreonam-avibactam and comparator antimicrobial agents tested against isolates carrying new MBL variants collected in 2013 and 2014

Yr collectedcCountryOrganismEnzyme contentdSourceeWardfMIC (μg/ml)a,b
2013ThailandP. aeruginosagIMP-48RTI1128128>16>8>8>32NAj>4>8
2014ThailandP. aeruginosagIMP-48IAI3i6464>16>8>8>322>4>8
2014ThailandP. aeruginosagIMP-48RTI16464>16>8>8>322>4>8
2014ThailandP. aeruginosahIMP-48SSTI36464>16>8>8>324>4>8
2014ThailandP. aeruginosahIMP-48RTI4162>16>8>8>322>4>8
2014ThailandP. aeruginosahIMP-48SSTI412864>16>8>8>322>4>8
2014BrazilP. aeruginosaIMP-49Blood588>16>84>32218
2013ItalyK. pneumoniaeVIM-42, SHV-12UTI3640.06>168816NA>42
2014HungaryP. aeruginosaVIM-43kIAI488>16>8>8>322>4>8
2014PortugalP. aeruginosaVIM-44RTI444848>3221>8
2014ThailandP. aeruginosagVIM-45, VEB-1bRTI4>12864>16>8>8>322>48
2014ThailandP. aeruginosagVIM-45, VEB-1bRTI1>128128>16>8>8>322>4>8
2014RussiaK. pneumoniaeNDM-16, CTX-M-15, SHV-OSBL, TEM-OSBLBlood1640.12>16>8>8>320.5>40.25
2014RussiaK. pneumoniaeNDM-16, CTX-M-15, SHV-12, TEM-OSBLBlood2>1280.25>16>8>8>321>40.5
  • a ATM, aztreonam; ATM-AVI, aztreonam-avibactam; FEP, cefepime; MEM, meropenem; IPM, imipenem; AMK, amikacin; CST, colistin, LVX, levofloxacin; TGC, tigecycline.

  • b Colistin was tested with 0.002% polysorbate 80 against isolates collected in 2012 and 2013 per the recommendation of the CLSI Enterobacteriaceae Working Group and tested with and without polysorbate 80 against isolates collected in 2014. Values for colistin tested without polysorbate 80 are shown.

  • c Multiple isolates collected from the same site are listed chronologically according to collection date.

  • d OSBL, original-spectrum β-lactamase; includes TEM-1, TEM-2, SHV-1, and SHV-11.

  • e RTI, respiratory tract infection; SSTI, skin and soft tissue infection; blood, bloodstream; UTI, urinary tract infection; IAI, intra-abdominal infection.

  • f Ward types: 1, surgery general; 2, surgery ICU; 3, medicine general, 4, medicine ICU; 5, pediatric ICU.

  • g Isolates were collected from one of two medical centers that contributed 90.9% of MBL-positive isolates from Thailand.

  • h Isolates were collected from one of two medical centers that contributed 90.9% of MBL-positive isolates from Thailand.

  • i Isolate was collected on the day of admittance. All other isolates were collected after ≥48 h of hospitalization.

  • j NA, not available (not determined).

  • k Two P. aeruginosa isolates carrying VIM-43 were collected from the same medical center on the same day and were deemed to be duplicate isolates based upon patient and sample data provided by the investigator. The second isolate was excluded from analysis.