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 9, Number 8—August 2003
Letter

Community Transmission of Extended-Spectrum β-Lactamase

On This Page
Article Metrics
74
citations of this article
EID Journal Metrics on Scopus

Cite This Article

To the Editor: The spread of multiresistant gram-negative bacteria in the general population is a problem of paramount importance, but the responsible mechanisms are poorly understood. Several studies have focused on β-lactam resistance in Enterobacteriaceae isolated from stools in healthy people, but they did not specifically investigate the extended-spectrum β-lactamases (ESBL). Furthermore, none of these studies detected ESBL in the evaluated population (1,2). We performed three survey studies to determine the incidence of Enterobacteriaceae strains producing ESBLs in the stools of outpatients attending our hospital. The first study was performed during a 4-month period (February–May 2001), the second during a 3 month-period (April–June 2002), and the third during 1 month (October 2002).

Stool samples were spread onto plates of MacConkey agar containing 2 mg/L of cefotaxime. A colony of each distinct morphotype was analyzed further. Species were identified according to conventional methods (3). The susceptibility to β-lactam antibiotics was determined by the disk-diffusion test, following recommendations of the National Committee for Clinical Laboratory Standards (4,5). The interpretative reading of the antibiogram was performed according to standard guidelines (46). The MICs of cefotaxime and ceftazidime, with and without clavulanic acid, were later determined by E test (AB Biodisk, Solna, Sweden). Strains producing ESBL were defined as strains showing synergism between amoxicillin-clavulanic acid and cefotaxime, ceftazidime, cefepime, or aztreonam (4,5).

All strains suspected of carrying a resistance pattern compatible with hyperproduction of the chromosomal enzymes, as well as resistant strains without synergy, were disregarded. During the first period, 15 (2.1%) of 707 outpatients were carriers of Escherichia coli (14 patients) or Proteus mirabilis (1 patient) with ESBL. This percentage increased during the second period, when 17 (3.8%) of 454 outpatients were carriers of E. coli with ESBL, and again in the third period, when 12 (7.5%) of 160 were carriers of E. coli (11 patients) or Enterobacter cloacae (1 patient) with ESBL. Characterization of the different ESBL isolated during the three study periods is in process. Although Klebsiella pneumoniae carrying ESBL has been detected in our hospital (7), as well as in other hospitals in Barcelona (8), no ESBL-producing K. pneumoniae strains were identified in this survey.

Although we did not disregard either the patients’ previous treatment with antibiotics or previous hospitalization, these patients came to the hospital from the community carrying strains that express ESBL. Moreover, during these three periods we observed a significant increase in the frequency of ESBL carriers (from 2.1% to 7.5%; p<0.005). These data suggest that the community could be a reservoir for these enzymes, as occurs with other microorganisms (911). Many questions remain unanswered regarding the diffusion mechanisms of this resistance in the community. Confirmation of community-based transmission of ESBL would indicate a need for heightened vigilance and further studies to determine the reservoirs and vehicles for dissemination of ESBL within the community.

Top

Beatriz Mirelis*†Comments to Author , Ferran Navarro*†, Elisenda Miró*, Raul Jesús Mesa*, Pere Coll*†, and Guillem Prats*†
Author affiliations: *Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; †Universitat Autònoma de Barcelona, Barcelona, Spain

Top

References

  1. Briñas  L, Zarazaga  M, Saenz  Y, Ruiz-Larrea  F, Torres  C. β-Lactamases in ampicillin-resistant Escherichia coli isolates from foods, humans, and healthy animals. Antimicrob Agents Chemother. 2002;46:315663. DOIPubMedGoogle Scholar
  2. Österblad  M, Hakanen  A, Manninen  R, Leistevuo  T, Peltonen  R, Meurman  O, A between-species comparison of antimicrobial resistance in enterobacteria in fecal flora. Antimicrob Agents Chemother. 2000;44:147984. DOIPubMedGoogle Scholar
  3. Murray  P, Baron  E, Pfaller  M, Tenover  F, Yolken  R. Manual of clinical microbiology. 7th ed. Washington: American Society for Microbiology; 1999.
  4. National Committee for Clinical Laboratory Standards. Performance standards for antimicrobial disk susceptibility test. Document M2-A7. 7th ed. Wayne (PA): The Committee; 2000.
  5. National Committee for Clinical Laboratory Standards. Supplemental tables: disk diffusion. Document M100-S10. Wayne (PA): The Committee; 2000.
  6. Livermore  DM. β-Lactamases in laboratory and clinical resistance. Clin Microbiol Rev. 1995;8:55784.PubMedGoogle Scholar
  7. Sabaté  M, Miró  E, Navarro  F, Vergés  C, Aliaga  R, Mirelis  B, Beta-lactamases involved in resistance to broad-spectrum cephalosporins in Escherichia coli and Klebsiella spp. clinical isolates collected between 1994 and 1996, in Barcelona (Spain). J Antimicrob Chemother. 2002;49:98997. DOIPubMedGoogle Scholar
  8. Hernández  JR, Pascual  A, Cantón  R, Martínez-Martínez  L. Grupo de Estudio de Infección Hospitalaria (GEIH). Escherichia coli y Klebsiella pneumoniae productores de betalactamasas de espectro extendido en hospitales españoles (Proyecto GEIH-BLEE 2000). Enferm Infecc Microbiol Clin. 2003;21:7782. DOIPubMedGoogle Scholar
  9. Chambers  HF. The changing epidemiology of Staphylococcus aureus? Emerg Infect Dis. 2001;8:17882. DOIPubMedGoogle Scholar
  10. Garau  J, Xercavins  M, Rodríguez-Carballeira  M, Gómez-Vera  JR, Coll  I, Vidal  D, Emergence and dissemination of quinolone-resistant Escherichia coli in the community. Antimicrob Agents Chemother. 1999;43:273641.PubMedGoogle Scholar
  11. Tomasz  A. New faces of an old pathogen: emergence and spread of multidrug-resistant Streptococcus pneumoniae. Am J Med. 1999;107:55S62S. DOIPubMedGoogle Scholar

Top

Cite This Article

DOI: 10.3201/eid0908.030094

Related Links

Top

Table of Contents – Volume 9, Number 8—August 2003

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.

Top

Comments

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

Beatriz Mirelis, Departament de Microbiologia, Hospital de la Santa Creu i Sant Pau, Av. Sant Antoni MªClaret, 167, 08025 Barcelona, Spain; fax: 34 93 2919070

Send To

10000 character(s) remaining.

Top

Page created: December 22, 2010
Page updated: December 22, 2010
Page reviewed: December 22, 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.
file_external