Staphylococcus aureus Biofilm: Morphology, Genetics, Pathogenesis and Treatment Strategies

Abstract

Staphylococcus aureus is a nosocomial bacterium causing different infectious diseases, ranging from skin and soft tissue infections to more serious and life-threatening infections such as septicaemia. S. aureus forms a complex structure of extracellular polymeric biofilm that provides a fully secured and functional environment for the formation of microcolonies, their sustenance and recolonization of sessile cells after its dispersal. Staphylococcus aureus biofilm protects the cells against hostile conditions, i.e., changes in temperature, limitations or deprivation of nutrients and dehydration, and, more importantly, protects the cells against antibacterial drugs. Drugs are increasingly becoming partially or fully inactive against S. aureus as they are either less penetrable or totally impenetrable due to the presence of biofilms surrounding the bacterial cells. Other factors, such as evasion of innate host immune system, genome plasticity and adaptability through gene evolution and exchange of genetic material, also contribute to the ineffectiveness of antibacterial drugs. This increasing tolerance to antibiotics has contributed to the emergence and rise of antimicrobial resistance (AMR), a serious problem that has resulted in increased morbidity and mortality of human and animal populations globally, in addition to causing huge financial losses to the global economy. The purpose of this review is to highlight different aspects of S. aureus biofilm formation and its overall architecture, individual biofilm constituents, clinical implications and role in pathogenesis and drug resistance. The review also discusses different techniques used in the qualitative and quantitative investigation of S. aureus biofilm and various strategies that can be employed to inhibit and eradicate S. aureus biofilm.

Integration of metabolomics and transcriptomics indicates changes in MRSA exposed to terpinen-4-ol

“…Antibiotics, AMP and plant extracts are commonly used in the treatment of biofilm infection. The anti-MRSA biofilm activity of terpinene-4-ol was studied in this paper [ 16 ] .…”

Activity of Moxifloxacin Against Biofilms Formed by Clinical Isolates of Staphylococcus aureus Differing by Their Resistant or Persister Character to Fluoroquinolones

“…The CFW signal was also significantly correlated with the RFP of clinical isolates, and to a lesser extent, with the moxifloxacin MIC ( Figures 2B,C ). Since poly- N -glucosamine is synthesized by enzymes encoded by the icaADBC operon, we quantified the expression of icaA for all clinical isolates after 3 h of incubation, knowing that the expression of this gene is upregulated mainly during the early stages of biofilm development ( Kot et al, 2018 ; Idrees et al, 2021 ). These expression levels were then compared to that of ATCC 33591, since this reference strain produced a biofilm containing a similar amount of viable bacteria as the clinical isolates (see Supplementary Figure 1B ) and the same persister fraction as ATCC 25923 (RPF = 1).…”

Thymus zygis Essential Oil: Phytochemical Characterization, Bioactivity Evaluation and Synergistic Effect with Antibiotics against Staphylococcus aureus

“…EOs have been used for centuries in perfumery, cosmetics and medicine and as part of spices and herbs in foods, and they are associated with a broad range of bioactive properties such as antibacterial and antioxidant activities [ 31 ]. The potential use of essential oils for developing promising antimicrobial agents with potential against S. aureus has been widely studied [ 32 , 33 ]. In the literature, it is described that T. zygis EO has antibacterial and antifungal activity against several microorganisms [ 34 , 35 , 36 ] and several other bioactive properties [ 15 , 21 , 37 ]; however, its interaction with antibiotics and several forms of antimicrobial activity required more in-depth studies.…”