356 research outputs found
Sixty years of antimicrobial use in animals:what is next?
No full textThis, the last in our series of feature articles celebrating 125 years of Veterinary Record, aims to provide an overview of antimicrobial use in animals. Starting with a journey through the history of antimicrobial use in animals, Luca Guardabassi gives his opinion on the current zoonotic risks associated with antimicrobial resistance and on how these risks might be tackled in the years to come
High diversity of genes and plasmids encoding resistance to third-generation cephalosporins and quinolones in clinical Escherichia coli from commercial poultry flocks in Italy
No full textThe aim was to investigate occurrence and diversity of plasmid-mediated resistance to third-generation cephalosporins (3GC) and quinolones in clinical Escherichia coli from 200 industrial poultry farms across Italy. E. coli was isolated from colibacillosis lesions in turkeys (n = 109), broilers (n = 98) and layers (n = 22) between 2008 and 2012. 3GC-resistant isolates were screened for extended-spectrum and AmpC Î2-lactamase (ESBL/AmpC), while all isolates were tested for plasmid-mediated quinolone resistance (PMQR) genes. ESBL/AmpC- and PMQR-positive isolates were typed by pulsed-field gel electrophoresis and antimicrobial susceptibility testing, and their plasmids were characterised by replicon typing, multilocus sequence typing, restriction fragment length polymorphism and conjugation. EBSL/AmpC genes (blaCTX-M-1, blaCTX-M-14, blaCTX-M-2, blaSHV-12and blaCMY-2) were detected in 7%, 9% and 4% of isolates from turkeys, broilers and layers, respectively. We identified seven ESBL/AmpC-encoding plasmid types, usually conjugative (78%), with a marked prevalence of IncI1/pST3 plasmids carrying blaCTX-M-1. PMQR occurred less frequently among isolates from turkeys (0.9%) compared to those from broilers (5%) and layers (4%). The PMQR genes qnrS, qnrB19 and oqxA/B were located on three plasmid types and two non-typeable plasmids, mostly (85%) conjugative. ESBL/AmpC- and PMQR-positive isolates were genetically unrelated and 64% of them were additionally resistant to aminoglycosides, sulfonamides and tetracyclines. Our data show that 3GC- and quinolone-resistant clinical E. coli in Italian poultry production represent a highly diverse population often resistant to most antimicrobials available for poultry. These findings underline the crucial need to develop new strategies for prevention and control of colibacillosis
Staphylococcus pseudintermedius in the dog: taxonomy, diagnostics, ecology, epidemiology and pathogenicity
No full textThe dog is the natural host of Staphylococcus pseudintermedius. Many research efforts are currently being undertaken to expand our knowledge and understanding of this important canine commensal and opportunistic pathogen.
The objective of this review is to summarize the current knowledge of the species, including the latest research outcomes, with emphasis on taxonomy, diagnostics, ecology, epidemiology and pathogenicity.
Despite the important taxonomic changes that have occurred over the past few years, the risk of misidentification in canine specimens is low and does not have serious consequences for clinical practice. Staphylococcus pseudintermedius carriage in the dog is more frequent and genetically heterogeneous compared with that of Staphylococcus aureus in man. It appears that these staphylococcal species have evolved separately through adaptation to their respective natural hosts and differ with regard to various aspects concerning ecology, population structure and evolution of antibiotic resistance.
Further understanding of the ecology and epidemiology of S. pseudintermedius is hampered by the lack of a standard method for rapid and discriminatory typing and by the limited data available on longitudinal carriage and population structure of meticillin-susceptible strains. With regard to pathogenicity, it is only now that we are starting to explore the virulence potential of S. pseudintermedius based on genomic and proteomic approaches, and more research is needed to assess the importance of individual virulence factors and the possible existence of hypervirulent strains
Complete sequences of IncHI1 plasmids carrying blaCTX-M-1 and qnrS1 in equine Escherichia coli provide new insights into plasmid evolution
No full textObjectives: To determine the structure of two multidrug-resistant IncHI1 plasmids carrying blaCTX-M-1 in Escherichia coli isolates disseminated in an equine clinic in the Czech Republic. Methods: A complete nucleotide sequencing of 239 kb IncHI1 (pEQ1) and 287 kb IncHI1/X1 (pEQ2) plasmids was performed using the 454-Genome Sequencer FLX system. The sequenceswere compared using bioinformatic tools with other sequenced IncHI1 plasmids. Results: A comparative analysis of pEQ1 and pEQ2 identified high nucleotide identity with the IncHI1 type 2 plasmids. A novel 24 kb module containing an operon involved in short-chain fructooligosaccharide uptake and metabolism was found in the pEQ backbones. The role of the pEQ plasmids in the metabolism of shortchain fructooligosaccharides was demonstrated by studying the growth of E. coli cells in the presence of these sugars. The module containing the blaCTX-M-1 gene was formed by a truncated macrolide resistance cluster and flanked by IS26 as previously observed in IncI1 and IncN plasmids. The IncHI1 plasmid changed size and gained the quinolone resistance gene qnrS1 as a result of IS26-mediated fusion with an IncX1 plasmid. Conclusions: Our data highlight the structure and evolution of IncHI1 from equine E. coli. A plasmidmediated sugar metabolic element could play a key role in strain fitness, contributing to the successful dissemination and maintenance of these plasmids in the intestinal microflora of horses. © The Author 2014
isolated from Danish pig farms
No full textNeomycin is the first-choice antibiotic for the treatment of porcine enteritis caused by enterotoxigenic Escherichia coli. Resistance to this aminoglycoside is on the rise after the increased use of neomycin due to the ban on zinc oxide. We identified the neomycin resistance determinants and plasmid contents in a historical collection of 128 neomycin-resistant clinical E. coli isolates from Danish pig farms. All isolates were characterized by whole-genome sequencing and antimicrobial susceptibility testing, followed by conjugation experiments and long-read sequencing of eight selected representative strains. We detected 35 sequence types (STs) with ST100 being the most prevalent lineage (38.3%). Neomycin resistance was associated with two resistance genes, namely aph(3')-Ia and aph(3')-Ib, which were identified in 93% and 7% of the isolates, respectively. The aph(3')-Ia was found on different large conjugative plasmids belonging to IncI1α, which was present in 67.2% of the strains, on IncHI1, IncHI2, and IncN, as well as on a multicopy ColRNAI plasmid. All these plasmids except ColRNAI carried genes encoding resistance to other antimicrobials or heavy metals, highlighting the risk of co-selection. The aph(3')-Ib gene occurred on a 19 kb chimeric, mobilizable plasmid that contained elements tracing back its origin to distantly related genera. While aph(3')-Ia was flanked by either Tn903 or Tn4352 derivatives, no clear association was observed between aph(3')-Ib and mobile genetic elements. In conclusion, the spread of neomycin resistance in porcine clinical E. coli is driven by two resistance determinants located on distinct plasmid scaffolds circulating within a highly diverse population dominated by ST100. IMPORTANCE Neomycin is the first-choice antibiotic for the management of Escherichia coli enteritis in pigs. This work shows that aph(3')-Ia and to a lesser extent aph(3')-Ib are responsible for the spread of neomycin resistance that has been recently observed among pig clinical isolates and elucidates the mechanisms of dissemination of these two resistance determinants. The aph(3')-Ia gene is located on different conjugative plasmid scaffolds and is associated with two distinct transposable elements (Tn903 and Tn4352) that contributed to its spread. The diffusion of aph(3')-Ib is mediated by a small non-conjugative, mobilizable chimeric plasmid that likely derived from distantly related members of the Pseudomonadota phylum and was not associated with any detectable mobile genetic element. Although the spread of neomycin resistance is largely attributable to horizontal transfer, both resistance determinants have been acquired by a predominant lineage (ST100) associated with enterotoxigenic E. coli, which accounted for approximately one-third of the strains
Transmission of antimicrobial resistance from pigs to humans: trues and lies
No full textThrough the years, use of antimicrobials in livestock has been the subject of an endless debate about the appropriateness of using these important medicines in the veterinary sector. This is a highly controversial topic involving ethical issues on animal welfare and human health, as well as economic interests by the pharmaceutical industry, the food industry and various professional categories, including farmers, veterinarians, pharmacists and researchers. As a consequence of all these factors, the debate has been often vigorous but not always scientifically unbiased. The aim of this lecture is to review the state-of-the-art on transmission of antimicrobial resistance (AMR) from pigs to humans with particular emphasis on specific risks that were overestimated by the scientific community in the past.</p
Antimicrobial use guidelines for treatment of urinary tract disease in dogs and cats: Antimicrobial guidelines working group of the international society for companion animal infectious diseases
No full textUrinary tract disease is a common reason for use (and likely misuse, improper use, and overuse) of antimicrobials in dogs and cats. There is a lack of comprehensive treatment guidelines such as those that are available for human medicine. Accordingly, guidelines for diagnosis and management of urinary tract infections were created by a Working Group of the International Society for Companion Animal Infectious Diseases. While objective data are currently limited, these guidelines provide information to assist in the diagnosis and management of upper and lower urinary tract infections in dogs and cats.J. Scott Weese, Joseph M. Blondeau, Dawn Boothe, Edward B. Breitschwerdt, Luca Guardabassi, Andrew Hillier, David H. Lloyd, Mark G. Papich, Shelley C. Rankin, John D. Turnidge and Jane E. Syke
- …
