Antimicrobial Susceptibility and Biofilm Production by Salmonella sp. Strains Isolated from Frozen Poultry Carcasses

Mj Sereno,Jg Pereira,Re Ziech,Jt Druziani,Ls Bersot

doi:10.1590/1806-9061-2016-0268

Abstract

ABSTRACT The objectives of this study were to evaluate the antimicrobial resistance and the biofilm-producing ability of Salmonella sp. strains isolated from frozen poultry carcasses. Antimicrobial susceptibility was tested by the disk-diffusion method. Biofilm-producing ability was determined in 96-well polystyrene microplates stained with crystal violet at 1%. Out of the 22 strains tested, all were multiresistant, that is, resistant to more than three antimicrobial classes, and 72.7% were able to form biofilms. The highest resistance rates obtained were against sulfonamides, tetracycline, and quinolones. On the other hand, 100% of the strains were sensitive to chloramphenicol. According to the rate of biofilm formation, 3 (13.6%) and 13 (59.1%) strains were classified as moderate and weak biofilm-producers, respectively, and 27.3% did not form biofilms. Biofilms increase the tolerance of microorganisms to stress, reducing their sensitivity to disinfectants and antimicrobials; favor equipment corrosion; and act as substrates for the adhesion of bacteria with lower biofilm-producing capacity. The results of the present study stress the importance of cleaning procedures in food processing plants and highlight the public health risks related to the emergence of multiresistant strains.

Highlights

Animal products, poultry products, have been reported as the main sources of Salmonella sp. foodborne diseases (FD) (Dallal et al, 2010)
In 2012, about 91,034 cases of salmonellosis were confirmed in humans in Europe (European Food Safety Authority & European Centre for Disease Prevention and Control, 2014), and it is estimated that, in the US, one million people are annually infected by Salmonella sp., with an average of 19,000 hospital admittances and 380 deaths (Scallan et al, 2011)
In Brazil, according to the Health Surveillance Agency of the Ministry of Health, between 2000 and 2014, there were 9,719 FD outbreaks, and Salmonella sp. was the most frequent microorganism associated with these outbreaks

Summary

Introduction

Poultry products, have been reported as the main sources of Salmonella sp. foodborne diseases (FD) (Dallal et al, 2010). In 2012, about 91,034 cases of salmonellosis were confirmed in humans in Europe (European Food Safety Authority & European Centre for Disease Prevention and Control, 2014), and it is estimated that, in the US, one million people are annually infected by Salmonella sp., with an average of 19,000 hospital admittances and 380 deaths (Scallan et al, 2011). Was the most frequent microorganism associated with these outbreaks. This microorganism was identified as the etiological agent of 1,564 outbreaks in the period (Brasil, 2014). Salmonellosis is generally clinically manifested by to self-limiting gastroenteritis, and does not require treatment in healthy patients. The routine and indiscriminate use of antibiotics have favored the emergence of resistant bacterial populations (Brasil, 2012), increasing the possibility of occurrence of treatment failures, and limiting therapeutic options both in human and veterinary medicine, when treatment is necessary (Souza et al, 2010a)

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Conclusion