Detection of Integrase Gene in E. coli Isolated from Pigs at Different Stages of Production System.

Eulalia De La Torre,Rocío Colello,María Ofelia Tapia,Edgardo Rodríguez,Nora Lía Padola,Analía Etcheverría,Fabián Amanto,Alejandro Luis Soraci

doi:10.1155/2014/489569

Abstract

Integrons are one of the genetic elements involved in the acquisition of antibiotic resistance. The aim of the present research is to investigate the presence of integrons in commensal Escherichia coli (E. coli) strains, isolated from pigs at different stages of production system and from the environment in an Argentinian farm. Five sows postpartum and five randomly chosen piglets from each litter were sampled by rectal swabs. They were sampled again at day 21 and at day 70. Environmental samples from the farm were also obtained. E. coli containing any integron class or combination of both integrons was detected by polymerase chain reaction in 100% of sows and in piglets at different stages of production: farrowing pen stage 68.1%;, weaning 60%, and growing/finishing 85.8%, showing an increase along the production system. From environmental samples 78.4% of E. coli containing any integron class was detected. We conclude that animals and farm environment can act as reservoirs for potential spread of resistant bacteria by means of mobile genetic elements as integrons, which has a major impact on production of food animals and that can reach man through the food chain, constituting a problem for public health.

Highlights

During the last years, the use of antimicrobial agents has markedly increased, both in human and veterinary medicine [1]
E. coli containing any integron class or combination of both integrons was detected by PCR in 5 sows tested (100%, Table 1)
We observed a significant increase in the amount of piglets harboring ECi1+ as they moved to different stages of production (P < 0.05), while there was a significant decrease of piglets harboring ECi2+ during weaning stage (P < 0.004) (Figure 2)

Summary

Introduction

The use of antimicrobial agents has markedly increased, both in human and veterinary medicine [1]. The main problem with the indiscriminately used antimicrobial agents to treat infections is the development of resistant strains of pathogenic bacteria. This issue is of major concern to human and animal health, mainly because it leads to a greater risk of therapeutic failure of standard infection management [2,3,4]. The presence of antimicrobial agents allows the selection of resistance genes in nonpathogenic bacteria, which, in time, can be horizontally transmitted to different species of pathogenic or zoonotic microorganisms [7,8,9]. Horizontal gene transfer seems to be the main cause of the rapid proliferation of International Journal of Microbiology antibiotic-resistance genes across a wide diversity of bacteria [10]

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Results

Conclusion