Underrated Staphylococcus species and their role in antimicrobial resistance spreading.

Ciro César Rossi,Monalessa Fábia Pereira,Marcia Giambiagi-Demarval

doi:10.1590/1678-4685-gmb-2019-0065

Abstract

The increasing threat of antimicrobial resistance has shed light on the interconnection between humans, animals, the environment, and their roles in the exchange and spreading of resistance genes. In this review, we present evidences that show that Staphylococcus species, usually referred to as harmless or opportunistic pathogens, represent a threat to human and animal health for acting as reservoirs of antimicrobial resistance genes. The capacity of genetic exchange between isolates of different sources and species of the Staphylococcus genus is discussed with emphasis on mobile genetic elements, the contribution of biofilm formation, and evidences obtained either experimentally or through genome analyses. We also discuss the involvement of CRISPR-Cas systems in the limitation of horizontal gene transfer and its suitability as a molecular clock to describe the history of genetic exchange between staphylococci.

Highlights

Every year, hundreds of thousands of deaths around the world are attributed to the ever increasing problem of antimicrobial resistance (Laxminarayan et al, 2016)
If the issue is not properly addressed, by the year of 2050, more than 10 million annual deaths will be caused by antimicrobial-resistant microorganisms, surpassing deaths by cancer (O’Neill, 2014). The accuracy of this frightening estimate is questioned by some authors, since the future scenario of disease treatment may be considerably different from the current one, the clinical, economical, and public health burden associated with antimicrobial resistance is undeniable (Kraker et al, 2016; Robinson et al, 2016)
Consistent with this, we have recently shown that S. haemolyticus strains are capable of producing biosurfactants that affect biofilm formation on abiotic surfaces (Rossi et al, 2016)

Summary

Introduction

Hundreds of thousands of deaths around the world are attributed to the ever increasing problem of antimicrobial resistance (Laxminarayan et al, 2016). Coagulase negative staphylococci (CoNS), especially S. epidermidis and S. haemolyticus, Genomic analyses indicate that many of the genetic determinants of resistance may have been exchanged between several staphylococcal species from different environments and hosts (Rolo et al, 2017; Rossi et al, 2017a; Kohler et al, 2018;). This includes species that are understudied and/or underestimated, either for having been recently discovered, rarely involved with infectious diseases, or for lacking canonical staphylococcal virulence factors. Recent evidence shows that these underrated species, despite not being usual pathogens, may have an important role in the exchange of antimicrobial resistance genes, by acting as gene-reservoirs for more pathogenic species, such as S. aureus (Otto, 2013; Rossi et al, 2017a, 2019)

Objectives

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Conclusion