Relatedness of Escherichia coli strains with different susceptibility patterns isolated from beagle dogs during ampicillin treatment

Mentula, Silja; Virtanen, Terhi; Kanervo-Nordström, Arja; Harmoinen, Jaana; Westermarck, Elias; Rautio, Merja; Huovinen, Pentti; Könönen, Eija

doi:10.1016/j.ijantimicag.2005.09.012

Cited by 10 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results found no correlation between phenotypes and genotypes within the same region (Fig 6), or within the same sample (ie, urine sample) (Fig 7). This observation is in agreement with studies that demonstrate antibiotic resistance patterns to significantly differ within PFGE types among uropathogenic E. coli isolated from dogs 19–21 . As reported previously, the possibility of horizontal transfer of mobile genetic elements to confer resistance, such as plasmids, integrons, or phage‐mediated exchange, is likely to have contributed to different PFGE patterns in our study 19–21 .…”

Section: Discussionsupporting

confidence: 93%

Antimicrobial Resistance Profiles and Clonal Relatedness of Canine and FelineEscherichia coliPathogens Expressing Multidrug Resistance in the United States

Shaheen

Boothe

Oyarzábal

et al. 2010

Journal of Veterinary Internal Medicine

View full text Add to dashboard Cite

Background: Antimicrobial resistance is increasing among Escherichia coli isolates associated with spontaneous infection in dogs and cats.Objectives: To describe E. coli resistance phenotypes and clonal relatedness and their regional prevalence. Animals: Isolates of E. coli (n 5 376) collected from dogs and cats in the United States between May and September 2005. Methods: Isolates submitted from the South, West, Northeast, and Midwest regions of the United States were prospectively studied. Phenotype was based on E-test susceptibility to 7 antimicrobials. Isolates were classified as no (NDR), single (SDR), or multidrug resistance (MDR). Clonal relatedness was determined by pulsed-field gel electrophoresis (PFGE).Results: One hundred and ninety-three (51%) isolates expressed resistance to at least 1 drug, yielding 42 phenotypes. SDR isolates (n 5 84; 44%, 8 phenotypes), expressed resistance most commonly to amoxicillin (30%, n 5 25) and least commonly to cefpodoxime (1%, n 5 1). MDR isolates (n 5 109; 56%, 31 phenotypes) were resistant to amoxicillin (96%, n 5 105), amoxicillinclavulanate (85%, n 5 93), and enrofloxacin (64%, n 5 70); 18% (n 5 20) were resistant to all drugs tested. The frequency of MDR did not differ regionally (P 5 .066). MDR minimum inhibitory concentrations (MICs) were 6-fold higher than SDR MICs (P o .0001). Dendrograms of 91 isolates representing 25 phenotypes revealed 62 different PFGE profiles.Conclusions and Clinical Importance: E. coli strains spontaneously infecting dogs and cats are genetically and phenotypically diverse. Given the current prevalence of MDR among clinical isolates of E. coli in United States, implementation of a robust surveillance program is warranted.

show abstract

Section: Discussionsupporting

confidence: 93%

Antimicrobial Resistance Profiles and Clonal Relatedness of Canine and FelineEscherichia coliPathogens Expressing Multidrug Resistance in the United States

Shaheen

Boothe

Oyarzábal

et al. 2010

Journal of Veterinary Internal Medicine

View full text Add to dashboard Cite

show abstract

“…In the present experiment, results obtained with the two phenotypic indicators of ampicillin resistance implied that all treatments had similar negative impacts on the gut microflora, with the emergence of a high level of resistance with all three dosage regimens. These results are consistent with those of previous studies demonstrating that ampicillin treatment could have a marked effect on the level of resistance in the intestinal microbiota of several species (9,21,33). Nevertheless, the phenotypic indicators commonly used to assess antibiotic resistance exhibit methodological features that impact both their metrological performances and their relevance.…”

Section: Discussionsupporting

confidence: 91%

Impact of Three Ampicillin Dosage Regimens on Selection of Ampicillin Resistance in Enterobacteriaceae and Excretion of bla _TEM Genes in Swine Feces

Bibbal

Dupouy

Ferré

et al. 2007

Appl Environ Microbiol

View full text Add to dashboard Cite

The aim of this study was to assess the impact of three ampicillin dosage regimens on ampicillin resistance among Enterobacteriaceae recovered from swine feces by use of phenotypic and genotypic approaches. Phenotypically, ampicillin resistance was determined from the percentage of resistant Enterobacteriaceae and MICs of Escherichia coli isolates. The pool of ampicillin resistance genes was also monitored by quantification of bla TEM genes, which code for the most frequently produced ␤-lactamases in gram-negative bacteria, using a newly developed real-time PCR assay. Ampicillin was administered intramuscularly and orally to fed or fasted pigs for 7 days at 20 mg/kg of body weight. The average percentage of resistant Enterobacteriaceae before treatment was between 2.5% and 12%, and bla TEM gene quantities were below 10 7 copies/g of feces. By days 4 and 7, the percentage of resistant Enterobacteriaceae exceeded 50% in all treated groups, with some highly resistant strains (MIC of >256 g/ml). In the control group, bla TEM gene quantities fluctuated between 10 4 and 10 6 copies/g of feces, whereas they fluctuated between 10 6 to 10 8 and 10 7 to 10 9 copies/g of feces for the intramuscular and oral routes, respectively. Whereas phenotypic evaluations did not discriminate among the three ampicillin dosage regimens, bla TEM gene quantification was able to differentiate between the effects of two routes of ampicillin administration. Our results suggest that fecal bla TEM gene quantification provides a sensitive tool to evaluate the impact of ampicillin administration on the selection of ampicillin resistance in the digestive microflora and its dissemination in the environment.The major mechanism of resistance to ␤-lactam antibiotics in gram-negative bacteria results from the production of ␤-lactamases. Most of these are coded by the plasmid-mediated bla TEM-1 gene (19,28). The continuous introduction of new ␤-lactam antibiotics with different activity spectra in human medicine has led to the selection of ␤-lactamase mutations, which confer resistance to the newly developed ␤-lactam antibiotics (25). ␤-Lactam antibiotics are also used in veterinary medicine, where they contribute to the selective pressure that leads to the emergence and diffusion of intestinal bacteria harboring resistance genes. Thus, commensal bacteria in the gut form a reservoir of antibiotic resistance genes potentially transmissible to humans via the food chain and the environment (27,29,34).Antimicrobial resistance in food animals deserves special attention. One of the most heavily medicated sectors is pig farming, with worldwide antibiotic consumption in pigs accounting for 60% of the antibiotics used in animals (10). A relationship has been demonstrated between the high use of antimicrobials in pig herds and the increased occurrence of resistant bacterial strains in their digestive tracts (4,13,34,37). When antibiotics are administered to pigs, both the level and time development of antibiotic exposure of the intestinal microflora are dependen...

show abstract

“…This result suggests that resistance traits were disseminated by vertical transmission through defined strains. When Mentula et al studied the impact of ampicillin administration on the fecal flora in dogs, they found considerable diversity in ampicillin-resistant strains using PFGE typing (32). Their results indicated that there was selection of genetically heterogeneous resistant E. coli strains rather than selection of a single clone or emergence of resistance in previously susceptible strains.…”

Section: Discussionmentioning

confidence: 99%

“…This method can also be used to evaluate the potential clonal spread of resistant strains (1,44). It has previously been used to investigate the dissemination and diversity of ampicillin-resistant commensal E. coli strains in cattle (22,23) and dogs (32).…”

mentioning

confidence: 99%

Relatedness of Escherichia coli Strains with Different Susceptibility Phenotypes Isolated from Swine Feces during Ampicillin Treatment

Bibbal

Dupouy

Prère

et al. 2009

Appl Environ Microbiol

View full text Add to dashboard Cite

The aim of this study was to examine the dynamics of the development of resistance in fecal Escherichia coli populations during treatment with ampicillin for 7 days in pigs. Before treatment, only 6% of the isolates were ampicillin resistant, whereas more than 90% of the isolates were resistant after days 4 and 7 of treatment. Ampicillin-resistant E. coli isolates were mainly multiresistant, and 53% of the isolates from the treated pigs had one phenotype that included resistance to six antibiotics (ampicillin, chloramphenicol, sulfonamides, tetracycline, trimethoprim, and streptomycin) at day 7. Determination of the frequency of the four phylogenetic groups showed that there was a shift in the E. coli population in ampicillin-treated pigs; before treatment 75% of the isolates belonged to phylogroup B1, whereas at day 7 85% of the isolates belonged to phylogroup A. Pulsed-field gel electrophoresis (PFGE) typing revealed that ampicillin treatment selected ampicillin-resistant isolates with genotypes which were present before treatment. Comparison of antimicrobial phenotypes and PFGE genotypes showed that resistance traits were disseminated by vertical transmission through defined strains. One PFGE genotype, associated with the six-antibiotic-resistant phenotype and including a specific combination of resistance determinants, was predominant among the ampicillin-resistant strains before treatment and during treatment. These data indicate that ampicillin administration selected various ampicillin-resistant isolates that were present in the digestive tract before any treatment and that E. coli isolates belonging to one specific PFGE genotype encoding resistance to six antibiotics became the predominant strains as soon as ampicillin was present in the digestive tract.Antimicrobial resistance in food animals deserves special attention, especially for pig farming, where worldwide consumption accounts for 60% of the antibiotics used in animals (13). The digestive tract of pigs can harbor antimicrobialresistant bacteria in the commensal flora, which contain a reservoir of antibiotic resistance genes potentially transmissible to humans via the food chain and the environment (37,39,46). Escherichia coli is an indicator species for studies of the level of antibiotic resistance of the fecal flora and has commonly been used for this purpose in pigs (43). Epidemiological studies were performed with commensal and pathogenic E. coli strains to identify the genetic determinants of the resistance. These studies provided a descriptive and molecular epidemiology analysis of fecal antimicrobial-resistant bacteria from animals (4,20,25,40). In addition, a relationship has been demonstrated between the use of antimicrobials in pig herds and the increased occurrence of resistant bacterial strains in the digestive tracts of pigs (3,16,46). However, the population processes underlying the emergence and spread of these antibiotic-resistant strains are little known, and how these strains are selected by antibiotic administration in the gut e...

show abstract

Relatedness of Escherichia coli strains with different susceptibility patterns isolated from beagle dogs during ampicillin treatment

Cited by 10 publications

References 23 publications

Antimicrobial Resistance Profiles and Clonal Relatedness of Canine and FelineEscherichia coliPathogens Expressing Multidrug Resistance in the United States

Antimicrobial Resistance Profiles and Clonal Relatedness of Canine and FelineEscherichia coliPathogens Expressing Multidrug Resistance in the United States

Impact of Three Ampicillin Dosage Regimens on Selection of Ampicillin Resistance in Enterobacteriaceae and Excretion of bla _TEM Genes in Swine Feces

Relatedness of Escherichia coli Strains with Different Susceptibility Phenotypes Isolated from Swine Feces during Ampicillin Treatment

Contact Info

Product

Resources

About

Relatedness of Escherichia coli strains with different susceptibility patterns isolated from beagle dogs during ampicillin treatment

Cited by 10 publications

References 23 publications

Antimicrobial Resistance Profiles and Clonal Relatedness of Canine and FelineEscherichia coliPathogens Expressing Multidrug Resistance in the United States

Antimicrobial Resistance Profiles and Clonal Relatedness of Canine and FelineEscherichia coliPathogens Expressing Multidrug Resistance in the United States

Impact of Three Ampicillin Dosage Regimens on Selection of Ampicillin Resistance in Enterobacteriaceae and Excretion of bla TEM Genes in Swine Feces

Relatedness of Escherichia coli Strains with Different Susceptibility Phenotypes Isolated from Swine Feces during Ampicillin Treatment

Contact Info

Product

Resources

About

Impact of Three Ampicillin Dosage Regimens on Selection of Ampicillin Resistance in Enterobacteriaceae and Excretion of bla _TEM Genes in Swine Feces