Open Access Open Badges Research article

Prevalence of urinary colonization by extended spectrum-beta-lactamase Enterobacteriaceae among catheterised inpatients in Italian long term care facilities

Luca Arnoldo1*, Roberta Migliavacca2, Laura Regattin3, Annibale Raglio4, Laura Pagani2, Elisabetta Nucleo2, Melissa Spalla2, Francesca Vailati4, Antonella Agodi5, Adriana Mosca6, Carla Zotti7, Stefano Tardivo8, Ines Bianco9, Adele Rulli9, Paola Gualdi10, Pietro Panetta11, Carlo Pasini12, Mino Pedroni12 and Silvio Brusaferro1

Author Affiliations

1 Department of Medical and Biological Sciences, University of Udine, Udine, Italy

2 Department of Clinical Surgical Diagnostic and Paediatric Sciences, Sect. of Microbiology, University of Pavia, Pavia, Italy

3 Azienda per i Servizi Sanitari 3 - Alto Friuli, Udine, Italy

4 Microbiology and Virology, AO Ospedali Riuniti di Bergamo, Bergamo, Italy

5 University of Catania, Catania, Italy

6 University of Bari, Bari, Italy

7 University of Torino, Turin, Italy

8 University of Verona, Verona, Italy

9 Azienda Sanitaria Locale 2 Lanciano Vasto Chieti, Chieti, Italy

10 Azienda provinciale per i servizi sanitari – Provincia autonoma di Trento, Trento, Italy

11 Azienda Sanitaria Locale Taranto, Taranto, Italy

12 Azienda Ospedaliera di Desenzano del Garda, Desenzano del Garda, Italy

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BMC Infectious Diseases 2013, 13:124  doi:10.1186/1471-2334-13-124

Published: 6 March 2013



Long Term Care Facilities (LTCFs) play a key role in guaranteeing care to patients in developed countries. Many patients, mostly elderly, access LTCFs at some time in their lives, and their healthcare pathways often require them to move back and forth between hospital and outpatient settings. These patterns bring about new challenges regarding infection control, especially healthcare associated infections.


A point prevalence study was conducted in 23 Italian LTCFs, to identify colonization in patients with urinary catheter (>24 hours). Species identification, susceptibility tests and extended spectrum beta lactamase (ESBL) production screenings were performed using Vitek 2 System. Enterobacteria identified by Vitek 2 System as ESBL-producers or suspected AmpC hyperproducers on the basis of cephamycin resistance, were sent to a research laboratory where they underwent a double-disk synergy test. Finally, ESBL-producers were screened for bla resistance genes by PCR assay.


211 patients with catheter were screened, 185 out of 211 patients showed positive samples for the presence of Enterobacteriaceae, 114 of these 185 patients were colonized by extended spectrum cephalosporins resistant microorganisms. We identified a total of 257 Gram negative pathogens, of which 51.8% (133/257) were extended spectrum cephalosporins resistant. 7 out of 133 cephamycin not susceptible strains proved to be AmpC-type beta-lactamases and 125/133 ESBL-producers; 1 was not further characterized. 43 out of 257 (16.7%) E. coli, 37/257 (14.4%) P. mirabilis, 20/257 (7.8%), P. stuartii, 14/257 (5.4%) M. morganii, 7/257 (2.7%), K. pneumoniae, 4/257 (1.6%) C. koseri proved to be overall ESBL-producers by double-disk synergy test. Third and fourth generation cephalosporin resistant P. mirabilis, P. stuartii and M. morganii strains mainly harboured a blaTEM gene (95.9%), while 89.1% of E. coli were positive for the blaCTX-M determinant by PCR and sequencing. Patients with decubitus had a higher risk of colonization by at least one resistant isolate (p < 0.01). Samples of patients undergoing antibiotic therapy and patients with decubitus showed a higher risk (p < 0.05) of colonization by beta-lactam resistant microorganisms.


These data confirm the presence of high percentages of ESBL-positive Enterobacteria in Italian LTCFs and the predominance of CTX-M type ESBL in E. coli. The alarming presence of ESBL-producing Enterobacteriaceae in Italian LTCFs can seriously compromise the effectiveness of antibiotic therapy.acilities (LTCFs), Antimicrobial resistance.