Antimicrobial susceptibility among gram-positive and gram-negative blood-borne pathogens collected between 2012-2016 as part of the Tigecycline Evaluation and Surveillance Trial

Zhijie Zhang,Meng Chen,Ying Yu,Yong Liu,Sisi Pan

doi:10.1186/s13756-018-0441-y

Abstract

BackgroundAntimicrobial activity of tigecycline and comparator agents was assessedin vitroagainst 27857 isolates source from blood samples collected between 2012 and 2016 as part of the Tigecycline Evaluation and Surveillance Trial (TEST).MethodsThe broth microdilution methods was used to determine minimum inhibitory concentrations (MIC) of blood-borne isolates according to guildlines of the Clinical and Laboratory Standards Institute (CLSI). Antimicrobial susceptibility breakpoints from CLSI guidelines were used as standards to determine susceptibility against comparator agents, whereas tigecycline breakpoints were provided by the US Food and Drug Administration (FDA).ResultsMore than 91% Enterobacteriaceae isolates, belonging to Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacaeandSerratia marcescens, were susceptible to amikacin, meropenem, and tigecycline. Meropenem resistance was observed in 8% ofK.pneumoniae isolates worldwide. Extended-spectrum β-lactamase (ESBL) was produced in 15.9 and 20.9%E.coli and K.pneumoniaeisolates, respectively. MIC90 of tigecycline against Acinetobacter baumannii was 2 μg/ml. The highest proportion of susceptible A.baumanniiisolates was 70.8% for minocycline. Among P.aeruginose isolates worldwide, 71.1–94.9% were susceptible to six antibiotics. Almost all Staphylococcus aureusisolates were susceptible to linezolid(100%), vancomycin(100%), and tigecycline (99.9%). The proportion of methicillin-resistant S.aureus (MRSA) was 33.0% among S.aureusisolates worldwide; it was highest in Asia with 46.6%, followed by North America and Latin America with 37.7 and 34.2%, respectively. Vancomycin-resistant (VR) isolates represented 1.4% ofEnterococcus faecalis (VR.E.faecalis) and 27.6% of Enterococcus faecium(VR.E.faecium). Highest percentages of VR.E.faeciumwere found in North America and Latin America, with 61.6 and 58.1% of the isolates, respectively. Production of penicillin-resistant Streptococcus pneumoniae(PRSP) represented 9.0% of S. pneumoniae isolates worldwide; the PRSP proportion was 25.8% in Asia, 13.0% in Africa, and 11.8% in Latin America.ConclusionsIn our study, tigecycline was the only antibiotic that was active against over 90% of all major blood-borne pathogens. A global comparison revealed that antimicrobial resistance was higher in Africa, Asia and Latin America than in Europe and North America.

Highlights

Antimicrobial activity of tigecycline and comparator agents was assessedin vitroagainst 27857 isolates source from blood samples collected between 2012 and 2016 as part of the Tigecycline Evaluation and Surveillance Trial (TEST)
We report on the antimicrobial susceptibility of Gram-positive bacteria and Gram-negative bacteria isolated from blood specimen collected from around the world between 2012 and 2016
To determine the susceptibility to antimicrobial agents, breakpoints from the Clinical and Laboratory Standards Institute (CLSI) guidelines [4] were used as interpretative standards except for the tigecycline breakpoints, which were obtained from the US Food and Drug Administration(FDA) [5]

Summary

Introduction

Antimicrobial activity of tigecycline and comparator agents was assessedin vitroagainst 27857 isolates source from blood samples collected between 2012 and 2016 as part of the Tigecycline Evaluation and Surveillance Trial (TEST). Bloodstream infections, acquired in clinics are major cause of mortality in severe disease patients. More attention has been recently paied to bloodstream infections because of the severe effects on health, longer hospital stays, expensive hospitalization costs, and an increase in mortality. In a study on patients of intensive care units (ICU) in Japan,the initiation of an appropriate empirical antimicrobial treatment was associated with a lower 60-day mortality than that of an inappropriate therapy [2]. The selection of an empirical antimicrobial drug therapy should be based on clinical and epidemiological data. It is important for the clinical treatment of infections to have the information derived from epidemiological data, which differ in scope and focus, i.e., data collected from around the world, different regions,countries, provinces, and hospitals

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