Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 13, Number 2—February 2007

Catheter-related Bacteremia and Multidrug-resistant Acinetobacter lwoffii

On This Page
Article Metrics
citations of this article
EID Journal Metrics on Scopus

Cite This Article

To the Editor:Acinetobacter species are ubiquitous in the environment. In recent years, some species, particularly A. baumannii, have emerged as important nosocomial pathogens because of their persistence in the hospital environment and broad antimicrobial drug resistance patterns (1,2). They are often associated with clinical illness including bacteremia, pneumonia, meningitis, peritonitis, endocarditis, and infections of the urinary tract and skin (3). These conditions are more frequently found in immunocompromised patients, in those admitted to intensive care units, or in those who have intravenous catheters, and those who are receiving mechanical ventilation (4,5).

The role of A. baumannii in nosocomial infections has been documented (2), but the clinical effect of other Acinetobacter species has not been investigated. A. lwoffii (formerly A. calcoaceticus var. lwoffii) is a commensal organism of human skin, oropharynx, and perineum that shows tropism for urinary tract mucosa (6). Few cases of A. lwoffii bacteremia have been reported (3,57). We report a 4-year (2002–2005) retrospective study of 10 patients with A. lwoffii bacteremia admitted to a 600-bed teaching hospital in central Italy.

All 10 patients were immunocompromised; 8 had used an intravascular catheter (peripheral or central) and 2 had used a urinary catheter. Blood cultures of the patients were analyzed with the BacT/ALERT 3D system (bioMérieux, Marcy l’Etoile, France). Isolates were identified as A. lwoffii by using the Vitek 2 system and the API 20NE system (both from bioMérieux).

Susceptibilities of 10 A. lwoffii isolates to 18 antimicrobial drugs were determined by the broth microdilution method, according to Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS) guidelines (8). The drugs tested were amikacin, ampicillin-sulbactam, aztreonam, cefepime, cefotaxime, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, levofloxacin, meropenem, ofloxacin, piperacillin, piperacillin-tazobactam, tetracycline, tobramycin, and trimethoprim-sulfamethoxazole. MIC was defined as the lowest drug concentration that prevented visible bacterial growth. Interpretative criteria for each drug tested were as in CLSI guidelines (8). A. lwoffii resistant to >4 classes of drugs were defined as multidrug-resistant (MDR) isolates.

A. lwoffii isolates were genotyped by pulsed-field gel electrophoresis (PFGE) to determine their epidemiologic relatedness. Chromosomal DNA was digested with SmaI (9) and analyzed with a CHEF DR II apparatus (Bio-Rad Laboratories, Hercules, CA, USA). PFGE patterns were classified as identical, similar (differed by 1–3 bands), or distinct (differed by >4 bands) (10).

Among the 10 A. lwoffii isolates, 6 were susceptible to all drugs except cephalosporins (cefepime, cefotaxime, ceftazidime, and ceftriaxone) and aztreonam. The other 4 isolates were MDR: 3 were susceptible only to imipenem (MICs 1–4 μg/mL), meropenem (MICs 1–2 μg/mL), and amikacin (MICs 2–4 μg/mL). The fourth MDR strain was susceptible to imipenem (MIC 2 μg/mL), meropenem (MIC 2 μg/mL), amikacin (MIC 4 μg/mL), and ciprofloxacin (MIC 1 μg/mL). Seven antimicrobial drug resistance profiles were detected (Table).

Macrorestriction analysis of the A. lwoffii isolates identified 8 distinct PFGE types. Two MDR strains (strains 2 and 3 in the Table), which were isolated from patients in different wards, and 2 non-MDR strains (strains 8 and 9), which were isolated from patients in the same ward, had similar PFGE patterns and identical resistance phenotypes. These findings suggest nosocomial transmission. Nine of the 10 patients survived after catheter removal or treatment with appropriate antimicrobial drugs. These results confirm that catheter-related A. lwoffii bacteremia in immunocompromised hosts is associated with a low risk for death (4,6).

This study identified A. lwoffii MDR strains that cause bacteremia in immunocompromised catheterized patients. Our data are consistent with those of previous reports on the role of catheters as the principal source of A. lwoffii infections.


Luciano Tega*, Katia Raieta†, Donatella Ottaviani‡, Gian Luigi Russo†, Giovanni Blanco*, and Antonio Carraturo*Comments to Author 
Author affiliations: *Ospedale Santa Maria Goretti, Latina, Italy; †Istituto di Scienze dell’Alimentazione, Avellino, Italy; ‡Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche, Ancona, Italy;



  1. Murray CK, Hospenthal DR. Treatment of multidrug resistant Acinetobacter.Curr Opin Infect Dis. 2005;18:5026. DOIPubMedGoogle Scholar
  2. Bergogne-Berezin E, Towner KJ. Acinetobacter spp. as nosocomial pathogens: microbiological, clinical, and epidemiological features.Clin Microbiol Rev. 1996;9:14865.PubMedGoogle Scholar
  3. Valero C, García-Palomo JD, Matorras P, Fernández-Mazarrasa C, Gonzáles-Fernández C, Farinas MC. Acinetobacter bacteraemia in a teaching hospital, 1989–1998.Eur J Intern Med. 2001;12:4259. DOIPubMedGoogle Scholar
  4. Crowe M, Ispahani P, Humphreys H, Kelley T, Winter R. Bacteraemia in the adult intensive care unit of a teaching hospital in Nottingham, UK, 1985–1996.Eur J Clin Microbiol Infect Dis. 1998;17:37784.PubMedGoogle Scholar
  5. Seifert H, Strate A, Schulze A, Pulverer G. Vascular catheter-related bloodstream infection due to Acinetobacter johnsonii (formerly Acinetobacter calcoaceticus var. lwoffii): report of 13 cases.Clin Infect Dis. 1993;17:6326.PubMedGoogle Scholar
  6. Ku SC, Hsueh PR, Yang PC, Luh KT. Clinical and microbiological characteristics of bacteremia caused by Acinetobacter lwoffii.Eur J Clin Microbiol Infect Dis. 2000;19:5015. DOIPubMedGoogle Scholar
  7. Domingo P, Munoz R, Frontera G, Pericas R, Martinez E. Community-acquired pneumonia due to Acinetobacter lwoffii in a patient infected with the human immunodeficiency virus.Clin Infect Dis. 1995;20:2056.PubMedGoogle Scholar
  8. Clinical and Laboratory Standards Institute (CLSI). Performance standards for antimicrobial susceptibility testing: 15th informational supplement. CLSI/NCCLS M100-S15. Wayne (PA): The Institute; 2005.
  9. Prashanth K, Badrinath S. Epidemiological investigation of nosocomial Acinetobacter infections using arbitrarily primed PCR and pulse field gel electrophoresis.Indian J Med Res. 2005;122:40818.PubMedGoogle Scholar
  10. Tenover FC, Arbeit RD, Goering RV, Mickelsen PA, Murray BE, Persing DH, Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing.J Clin Microbiol. 1995;33:22339.PubMedGoogle Scholar




Cite This Article

DOI: 10.3201/eid1302.060858

Related Links


Table of Contents – Volume 13, Number 2—February 2007

EID Search Options
presentation_01 Advanced Article Search – Search articles by author and/or keyword.
presentation_01 Articles by Country Search – Search articles by the topic country.
presentation_01 Article Type Search – Search articles by article type and issue.



Please use the form below to submit correspondence to the authors or contact them at the following address:

Antonio Carraturo, Laboratorio di Microbiologia, Ospedale Santa Maria Goretti, Azienda Unità Sanitaria Locale di Latina, Via Canova, 04100 Latina, Italy;

Send To

10000 character(s) remaining.


Page created: June 29, 2010
Page updated: June 29, 2010
Page reviewed: June 29, 2010
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.