Tirushet Teshager

Monitoring and Characterization of Extended-Spectrum β-Lactamases in Escherichia coli Strains from Healthy and Sick Animals in Spain in 2003

ABSTRACT Genes encoding CTX-M-14, CTX-M-9, CTX-M-1, CTX-M-32, SHV-12, TEM-52, or CMY-2 β-lactamases were detected in 21 Escherichia coli strains recovered during 2003 from sick animals (11 of 459 [2.4%] strains) and healthy animals (10 of 158 [6.3%] strains) in Spain. Twelve of these strains harbored blaCTX-M genes and showed unrelated pulsed-field gel electrophoresis patterns.

armA and aminoglycoside resistance in Escherichia coli.

We report armA in an Escherichia coli pig isolate from Spain. The resistance gene was borne by self-transferable IncN plasmid pMUR050. Molecular analysis of the plasmid and of the armA locus confirmed the spread of this resistance determinant.

Surveillance of antimicrobial resistance in Escherichia coli strains isolated from pigs at Spanish slaughterhouses

Antimicrobial resistance can make the efficient treatment of bacterial infections in humans and animals more difficult. Antimicrobial use in food animals may be one of the factors contributing to resistance. The Spanish surveillance network VAV has established a baseline of antimicrobial resistance in Escherichia coli strains from healthy pigs. Minimum inhibitory concentration and patterns of resistance to antimicrobials used in animals and humans were determined for 205 faecal strains isolated in a sampling frame of four slaughterhouses in Spain from 220 pigs in 1998. Higher levels of resistance were seen against antimicrobial agents authorised for use in food animals especially tetracycline, sulphonamides, trimethoprim and amoxycillin. All isolates were susceptible to antimicrobials employed mainly in humans such as ceftazidime, cefotaxime, imipenem, aztreonam and amikacin.

Isolation of an SHV-12 β-Lactamase-Producing Escherichia coli Strain from a Dog with Recurrent Urinary Tract Infections

An Escherichia coli strain (EC98/4153-2) was isolated in 1998 (by the Microbiology and Parasitology Service, Complutense University, Veterinary Hospital, Madrid, Spain) from a urine specimen from a dog with a recurrent urinary tract infection, and this strain was submitted to the Network of

Resistance mechanisms and farm-level distribution of fecal Escherichia coli isolates resistant to extended-spectrum cephalosporins in pigs in Spain

INTRODUCTION Fecal Escherichia coli isolates showing a phenotype of reduced susceptibility or resistance to extended-spectrum cephalosporins are common among pigs in Spain. The aim of this study was to describe the main beta-lactam resistance mechanisms carried by these strains and their distribution at farm-level. MATERIALS AND METHODS Twenty-nine E. coli isolates showing reduced susceptibility or resistance to extended-spectrum cephalosporins were collected from a sampling frame of 80 pig farms distributed over 13 Spanish provinces. The survey was carried out at the slaughterhouse level in 2004. RESULTS Of the 29 isolates, 21 (72%) met the criteria for a positive phenotypic confirmatory test for extended-spectrum beta-lactamases (ESBL). The following ESBLs were detected: SHV-12 (12 isolates, 41%), CTX-M-1 (three isolates, 10%), CTX-M-9 (three isolates, 10%), and CTX-M-14 (three isolates, 10%). The remaining eight isolates (28%) were phenotypically non-ESBL, with seven of them (24%) showing mutations on the chromosomal ampC gene promoter at positions -42 (C-->T), -18 (G-->A), -1 (C-->T), and +58 (C-->T). A multiplex PCR for detection of plasmidic class C beta-lactamases was negative for all isolates. CONCLUSION Different ESBLs and other mechanisms linked to extended-spectrum cephalosporin resistance are widely distributed among fecal E. coli from slaughter pigs in Spain.

β-Lactamase Characterization in Escherichia coli Isolates with Diminished Susceptibility or Resistance to Extended-Spectrum Cephalosporins Recovered from Sick Animals in Spain

A total of 1439 Escherichia coli isolates from sick animals were received from the Spanish Network of Veterinary Antimicrobial Resistance Surveillance (VAV) from 1997 to 2001. Antimicrobial susceptibility tests were performed and diminished susceptibility to cefotaxime and ceftazidime was identified in 2.5% and 2.8% of the isolates, respectively. Beta-lactamase characterization was carried out in the group of 20 E. coli isolates with both characteristics. The MIC ranges of different beta-lactams showed by these 20 isolates were as follows (in microg/ml): ampicillin (64-->256), amoxicillin-clavulanic acid (4-64), ticarcillin (8-->128), cefazolin (32-->256), cefoxitin (4-->128), cefotaxime (1-64), ceftazidime (2-->64), ceftriaxone (0.5-64), imipenem (< or = 0.06-0.25), and aztreonam (2-->32). TEM, SHV, CMY, and FOX beta-lactamase genes were analyzed by PCR and sequencing. The beta-lactamase genes detected were the following ones (number of isolates): bla(TEM-1b) (3), bla(TEM-1a) (1), bla(TEM-30f) (2), bla(TEM-1b) + bla(CMY-2) (2), and bla(SHV-12) (1). Sequences of the promoter and/or attenuator region of the chromosomal ampC gene were studied in all the 20 isolates. Mutations at position -42 or -32 were detected in 16 isolates and these mutations were associated with the presence of a TEM type beta-lactamase in 6 isolates. Besides, a high variety of plasmidic beta-lactamases was detected including TEM-30 and CMY-2. To our knowledge, this is the first time that TEM-30 beta-lactamase has been detected in E. coli isolates of animal origin.

Prevalence of vancomycin-resistant Enterococcus faecium (VREF) in pig faeces from slaughterhouses in Spain

A study to estimate the prevalence of vancomycin-resistant Enterococcus faecium in faecal samples from pigs at slaughterhouses in Spain was carried out between November 1998 and January 1999 with 900 samples taken from four abattoirs representing 9.7% of all pig slaughtered in 1998. Using a selective enrichment broth with vancomycin (8microg/ml), 64 samples (7.1%; 95% CI: 5.5, 9.0%) had E. faecium vancomycin-resistant strains that showed minimal inhibitory concentrations of 256microg/ml (62 strains) and 512microg/ml (two strains). Results by farm showed that 43 of the 240 pig farms represented in the sampling had at least one faecal sample with vancomycin-resistant E. faecium.