The Ciliate Protist &amp;lt;i&amp;gt;Tetrahymena pyriformis&amp;lt;/i&amp;gt; as a Cellular Adhesion Model for the Pathogenic Bacterium &amp;lt;i&amp;gt;Staphylococcus aureus&amp;lt;/i&amp;gt;

Sofia Jarmouni,Mohammed Benlahfid,Bouchra El Khalfi,Nezha Senhaji,Abdelaziz Soukri,Aurelio Serrano Delgado

doi:10.4236/abb.2017.812036

Abstract

Staphylococcus aureus is one of the main pathogenic agents responsible for nosocomial and community-acquired bacterial infections. The pathogenicity of this Gram-positive bacterium is ensured by its different adhesion factors. Collagen and the extracellular glycoprotein adhesin are among the Staphylococcus most important virulence factors. It has been shown that most of the S. aureus strains carry the ica operon, responsible for biofilm production. However, the coexpression of the icaA and the icaD genes is necessary for complete biofilm synthesis. The aim of our study was to study a collection of 15 clinical strains of S. aureus from different sources for the presence of can and icaD genes coding intercellular adhesion proteins. We also intended to estimate the strains’ ability to form biofilms by the red Cong method and to test the adhesion ability of S. aureus to the ciliated protist Tetrahymena pyriformis, which we used as a novel cellular adhesion model. Finally, we checked the adhesion’s inhibition capacity of some plants extracts. The molecular detection of adhesion genes revealed that 80% of strains are cna positive, and 73% are icaD positive. Qualitative biofilm production of S. aureus revealed that 66.6% of strains were slime producers. The adhesion test revealed that 20% of strains are strongly adhering to T. pyriformis and that the Clematis cirrhosa extract has an anti-adhering effect of S. aureus to the ciliate T. pyriformis.

Highlights

Staphylococcus is a genus of Gram-positive bacteria in shells shape, without flagellum, which has a cellular envelope made of a unique plasma membrane, surrounded by a relatively thick cell wall [1] [2]
Molecular identification of S. aureus strains In this study, all the fifteen clinical bacterial strains collected were identified by PCR using the AF gene
Molecular detection of cna and icaD genes The cna gene PCR amplification of the cna gene encoding the collagen-binding adhesin protein was performed for all Staphylococcus aureus clinical strains using genomic DNA as a template, and the results were revealed on 1% agarose gels

Summary

Introduction

Staphylococcus (from the Greek: σταφυλή, staphylē, “grape” and κόκκος, kókkos, “granule”) is a genus of Gram-positive bacteria in shells shape, without flagellum, which has a cellular envelope made of a unique plasma membrane, surrounded by a relatively thick cell wall [1] [2]. As described in 1881 by Alexander Ogston, it is a Gram-positive spherical bacterium, optional anaerobic, immobile and making regular clusters like bunch of grapes of 0.5 to 1.5 μm. It has the most important pathogenicity potential among the Staphylococci, and is the only strain able to produce coagulase, an exoenzyme able to coagulate blood plasma, which allows Staphylococcus fast and easy identification. It is one of the main causes of nosocomial and community-acquired infections. These infections involve biofilms, which are multicellular communities omnipresent in natural, industrial and medical areas and can affect human health [3] [4]

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