Susceptibility to tigecycline of isolates from samples collected in hospitalized patients with secondary peritonitis undergoing surgery☆

Received 8 July 2009; accepted 30 October 2009. published online 18 December 2009.

Abstract

Activity of tigecycline against nosocomial secondary peritonitis isolates collected along 18 months in 29 Spanish hospitals was tested by Etest in a central laboratory, considering Food and Drug Administration (FDA)/British Society for Antimicrobial Chemotherapy (BSAC)/European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. A total of 600 facultative/aerobic isolates (392 Gram negative, 208 Gram positive) and 100 anaerobes were tested. None of the 220 Escherichia coli isolates was resistant to tigecycline (MIC50/MIC90 = 0.25/0.5 μg/mL), with 0.5% (FDA breakpoint) and 3.6% (BSAC/EUCAST breakpoint) intermediate strains. All Extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates (15 strains), all Klebsiella pneumoniae, and Klebsiella oxytoca isolates (42 strains) were susceptible to tigecycline. No isolates resistant to tigecycline were found among Streptococcus viridans, Staphylococcus aureus, and Enterococcus faecium, but 18.9% of Enterococcus faecalis strains were intermediate following BSAC/EUCAST breakpoints. All (but 1) isolates of the Bacteroides fragilis group (n = 45) were tigecycline susceptible, as well as Gram-positive anaerobes. Tigecycline offers an adequate activity profile against isolates from secondary peritonitis when tested by Etest regardless of the breakpoints used for categorization.

Keywords: Secondary peritonitis, Tigecycline, E. coli, Enterococcus, Bacteroides

a Microbiology Department, Hospital Universitari de Bellvitge, IDIBELL, University of Barcelona, Feixa Llarga, s/n, 08907 Hospitalet de Llobregat, Barcelona, Spain and CIBER for Respiratory Diseases

b Microbiology Department, Hospital Arquitecto Marcide-Novoa Santos, Estrada de San Pedro de Leixa s/n, 15405 Ferrol, A Coruña, Spain

c Microbiology Department, Hospital General Universitario Gregorio Marañón, Dr. Esquerdo 46, 28007 Madrid, Spain

d Microbiology Department, Hospital Royo Villanova, Avda. San Gregorio 30, 50015 Zaragoza, Spain

e Microbiology Department, Hospital Universitario San Carlos, Martin Lagos s/n, 28040 Madrid, Spain

f Microbiology Department, Hospital Virgen del Camino, Irunlarrea 4, 31008 Pamplona, Spain

g Microbiology Department, Hospital de Galdakao, Barrio Labeaga s/n, 48960 Galdakao, Vizcaya, Spain

h Microbiology Department, Hospital General Universitario de Alicante, Maestro Alonso 109, 03010 Alicante, Spain

i Microbiology Department, School of Medicine, Universidad Complutense, Avda. Complutense s/n, 28040 Madrid, Spain

j Microbiology Department, Hospital Universitario Fundación de Alcorcón, Budapest 1, 28922 Alcorcón, Madrid, Spain

k Medical Department, Wyeth Farma S.A., Ctra. N-I, km. 23 Desvío Algete Km.1, San Sebastián de los Reyes, Madrid, Spain

Corresponding author. Tel.: +34-91-3941505; fax: +34-91-3941511.

☆ This study was supported in part by an unrestricted grant from Wyeth Farma, Madrid, Spain.

1 NG-E is an employee of Wyeth Farma, Madrid, Spain.

PII: S0732-8893(09)00443-X

doi:10.1016/j.diagmicrobio.2009.10.018

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