title: Tigecycline activity tested against antimicrobial resistant surveillance subsets of clinical bacteria collected worldwide (2011).
abstract: Tigecycline was approved by the United States Food and Drug Administration in 2005 and has generally retained activity against resistant Gram-positive and Gram-negative organisms. We monitored the in vitro activity of this glycylcycline in 2011 for continued potency worldwide. A total of 22,005 unique clinical isolates were consecutively collected in North America (NA; 9232 isolates), Europe (EU; 6776), Latin America (LA; 2016), and Asia-Pacific region (APAC, 3981) and tested for susceptibility according to the reference broth microdilution method recommendations against tigecycline and numerous comparators. Oxacillin (methicillin) resistance rates in methicillin-resistant Staphylococcus aureus (MRSA) were 49.3%, 30.2%, 42.9%, and 37.8%, and vancomycin resistance rates in enterococci (VRE) were 27.0%, 11.3%, 6.3%, and 4.0% in NA, EU, LA, and APAC, respectively. All MRSA (2839) and >99% of VRE were susceptible to tigecycline. Among Escherichia coli, extended-spectrum β-lactamase (ESBL) rates varied from 12.6% in the NA to 57.4% in APAC, and only one strain was nonsusceptible to tigecycline. Tigecycline was active against ESBL phenotype (96.5-98.4% susceptible) and meropenem-nonsusceptible Klebsiella spp. (94.3-100.0% susceptible). Only 4 of 213 (1.9%) meropenem-nonsusceptible Klebsiella spp. were tigecycline-nonsusceptible, all with tigecycline minimum inhibitory concentration (MIC) of 4 μg/mL (intermediate). Among ceftazidime-nonsusceptible Enterobacter spp., 94.7-98.2% were susceptible to tigecycline. Meropenem-nonsusceptible Acinetobacter spp. varied from 51.2% in NA to 80.9% in APAC; and 83.8% (LA) to 93.9% (APAC) of strains were inhibited at a tigecycline MIC of ≤2 μg/mL. Tigecycline showed potent activity against Stenotrophomonas maltophilia (89.3-98.3% inhibited at ≤2 μg/mL). In summary, tigecycline has sustained potent activity and a broad-spectrum against clinically important bacteria causing infections worldwide, including multidrug-resistant organism subsets.
authors.affiliation: JMI Laboratories, North Liberty, IA 52317, USA. helio-sader@jmilabs.com
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.forename: Robert K
authors.initials: RK
authors.lastname: Flamm
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000150:Acinetobacter / Q000187:drug effects / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001208:Asia; D002442:Ceftazidime / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D004754:Enterobacter / Q000187:drug effects / Q000302:isolation & purification; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification; D005060:Europe; D007709:Klebsiella / Q000187:drug effects / Q000302:isolation & purification; D007843:Latin America; D000077731:Meropenem; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives* / Q000494:pharmacology; D009656:North America; D011786:Quality Control; D020615:Stenotrophomonas maltophilia / Q000187:drug effects / Q000302:isolation & purification; D013845:Thienamycins / Q000494:pharmacology; D000078304:Tigecycline
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D000078304:Tigecycline; D002442:Ceftazidime; D000077731:Meropenem; D008911:Minocycline