Assessment of the Activity of Tigecycline against Gram-Positive and Gram-Negative Organisms Collected from Italy between 2012 and 2014, as Part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.)

Abstract

As part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T) we report the in vitro activity of tigecycline and its comparators against Gram-negative and Gram-positive organisms collected from Italian centers between 2012 and 2014. Minimum inhibitory concentrations were determined according to the broth microdilution methodology of the Clinical and Laboratory Standards Institute, and antimicrobial resistance was determined using the European Committee on Antimicrobial Susceptibility Testing interpretive criteria. Among the Enterobacteriaceae, 31% of Escherichia coli isolates, 22% of Klebsiella pneumoniae, and 1% of Klebsiella oxytoca were extended-spectrum β-lactamase producers (ESBLs). Resistance rates among ESBL-K. pneumoniae and ESBL-E. coli to meropenem were 24% and <1%, respectively. Thirty-seven percent of K. pneumoniae were multidrug resistant (MDR) strains. Resistance rates among isolates of Acinetobacter baumannii to amikacin, levofloxacin and meropenem were between 84% and 94%. Eighty percent of A. baumannii isolates were MDR strains. Methicillin-resistant Staphylococcus aureus (MRSA) accounted for 38% of S. aureus isolates. No isolates of MRSA were resistant to linezolid, tigecycline or vancomycin. Antimicrobial resistance remains a problem in Italy with increasing numbers of MDR organisms. Despite high levels, MRSA rates appear to be stabilising. Tigecycline retains its in vitro activity against the majority of organisms, including those with multidrug resistance.

Bloodstream infections caused by Acinetobacter species with reduced susceptibility to tigecycline: clinical features and risk factors

“…The recent wide dissemination of XDR Acinetobacter spp, which are only susceptible to colistin and tigecycline (Falagas et al, 2006), has resulted in the treatment of these infections becoming a serious clinical challenge, and the evidence suggests that hospitalacquired Acinetobacter infections prolong the length of hospital stay and increase healthcare costs (Peleg et al, 2008;Sunenshine et al, 2007;Giammanco et al, 2017;Stefani and Dowzicky, 2016). For this reason, the treatment of XDR Acinetobacter spp is challenging, and new therapeutic options are required.…”

Insight into <em>Acinetobacter baumannii</em>: pathogenesis, global resistance, mechanisms of resistance, treatment options, and alternative modalities

“… 70 It has shown effectiveness against A. baumannii and other species of Acinetobacter in large number of studies. 71 …”

Antibiotic Susceptibility Patterns for Carbapenem-Resistant Enterobacteriaceae

“…Stefani and Dowzicky reported the activity of tigecycline against Gram-negative organisms in Italy between 2012 and 2014. They showed increased resistance to tigecycin in this period from 7.4 to 15.8 in MDR K. pneumoniae [ 26 ].…”