title: A prospective evaluation of synergistic effect of sulbactam and tazobactam combination with meropenem or colistin against multidrug resistant Acinetobacter baumannii.
abstract: The present study evaluates the synergistic effect of sulbactam/tazobactam in combination with meropenem or colistin against multidrug resistant (MDR) Acinetobacter baumannii isolated from hospitalized patients from a tertiary care hospital in Saudi Arabia. During the study period, 54 multidrug and carbapenem-resistant isolates of A. baumannii isolates were collected from blood and respiratory samples of patients with ventilator-associated pneumonia or bacteremia. Microbroth checkerboard assay (CBA) and E-test were performed to look for synergistic interface of sulbactam and tazobactam with meropenem or colistin. All 54 MDR isolates of A. baumannii were resistant to carbapenem. Minimum inhibitory concentration [50/90] value against sulbactam, tazobactam, meropenem, colistin was found to be 64/128, 64/128, 64/256, and 0.5/1.0 respectively. Synergy was detected in more isolates with CBA compared to E-test. All four combinations showed significant synergistic bactericidal activity. However, the combination with colistin showed greater synergistic effect than combination with meropenem. Antagonism was not detected with any of the combinations and any method, but indifference was seen in tazobactam and colistin combination alone. A significant bactericidal effect was seen with sulbactam combination with meropenem or colistin in both methods. A combination therapy can be a choice of treatment. As colistin is known to exhibit nephrotoxicity, the combination of sulbactam and meropenem might be considered as an alternative antibiotic treatment for such multi- and extremely resistant bacteria. Yet, sample size is small in our study, so further well-designed in vitro and clinical studies on large scale should confirm our findings.
authors.affiliation: . dr.mmarieali@gmail.com.
authors.forename: Mohammed Ali M
authors.initials: MA
authors.lastname: Marie
authors.forename: Lakshmana Gowda
authors.initials: LG
authors.lastname: Krishnappa
authors.forename: Alhusain J
authors.initials: AJ
authors.lastname: Alzahrani
authors.forename: Murad A
authors.initials: MA
authors.lastname: Mubaraki
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Alyousef
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy; D040981:Acinetobacter baumannii / Q000187:drug effects*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003091:Colistin / Q000008:administration & dosage / Q000627:therapeutic use*; D004338:Drug Combinations; D024881:Drug Resistance, Bacterial; D004357:Drug Synergism; D006801:Humans; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D011446:Prospective Studies; D013407:Sulbactam / Q000008:administration & dosage / Q000627:therapeutic use*; D000078142:Tazobactam; D013845:Thienamycins / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D013845:Thienamycins; D010397:Penicillanic Acid; D000077731:Meropenem; D013407:Sulbactam; D000078142:Tazobactam; D003091:Colistin