Antimicrobial Resistance and Other Related Virulence Factors in Staphylococcus Spp isolated from Food, Environmental and Humans in Italy

Immacolata Anacarso,Moreno Bondi,Carla Condò,Carla Sabia,Patrizia Messi,Ramona Iseppi,Simona De Niederhausern

doi:10.13189/ujmr.2013.010101

Abstract

We investigated the presence of antibiotic-resistances and others important virulence factors in coagulase negative and positive staphylococci, isolated from several sources (food, environmental and clinical). Thirty-four staphylococci were isolated and identified (28 coagulase-positive were identified as Staphylococcus aureus, 6 remaining Coagulase Negative Staphylococci were identified as 3 S. epidermidis, 2 S. warneri, 1 S. hycus). All the strains were analyzed both with phenotypic and genotypic assays in order to evaluate the virulence factors and the susceptibility against antibiotics and to correlate them to the sources of isolation. Results showed that isn't a direct correlation between features researched and isolation, and the different virulence factors are as widespread as antibiotic-resistance. The isolation from food of a strain of Staphylococcus aureus with a high methicillin resistance was very interesting. 15 of the 34 strains were found to possess multi-drug resistance and in 7 cases with Minimum Inhibitory Concentration(MIC) really very high; also in this case there is no distinction between the coagulase-positive and coagulase-negative staphylococci and their origin of isolation.

Highlights

Staphylococci are gram-positive, non-motile, not producing spores ubiquitous bacteria that include different opportunistic/pathogenic species, responsible for human and animal infections
A direct relationship between bacterial virulence factors and sources of isolation did not emerged in the present investigation
In this study we noted that all S. aureus strains are endowed with a lot of virulence factors, feature much less represented among the Coagulasenegative staphylococci (CNS) isolates that were all positive for the production of slime

Summary

Introduction

Staphylococci are gram-positive, non-motile, not producing spores ubiquitous bacteria that include different opportunistic/pathogenic species, responsible for human and animal infections. These groups of microorganisms colonize skin, hair, nose and throat of people and animals and from these sources they can be transferred to food because both organisms are the main reservoirs [1]. S.aureusis a common pathogen associated with multiple disease processes, an important nosocomial and community-acquire dpathogen [5]and one of the major bacterial agents causing foodborne diseases in humans worldwide [6, 7] These microorganisms have a formidable range of potential virulence determinants [8]

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Conclusion