Novel treatment dynamics for biofilm-related infections

Introduction: As a result of progress in medical care, a huge number of medical devices are used in the treatment of human diseases. In turn, biofilm-related infection has become a growing threat due to the tolerance of biofilms to antimicrobials, a problem magnified by the development of antimicrobial resistance worldwide. As a result, successful treatment of biofilm-disease using only antimicrobials is problematic.Areas covered: We summarize some alternative approaches to classic antimicrobials for the treatment of biofilm disease. This review is not intended to be exhaustive but to give a clinical picture of alternatives to antimicrobial agents to manage biofilm disease. We highlight those strategies that may be closer to application in clinical practice.Expert opinion: There are a number of outstanding challenges in the development of novel antibiofilm therapies. Screening for effective antibiofilm compounds requires models relevant to all clinical scenarios. Although in vitro research of anti-biofilm strategies has progressed significantly over the past decade, there is a lack of in vivo research. In addition, the complexity of biofilm biology makes it difficult to develop a compound that is likely to provide the single 'magic bullet'. The multifaceted nature of biofilms imposes the need for multi-targeted or combinatorial therapies.

Phage therapy as a renewed therapeutic approach to mycobacterial infections: a comprehensive review

Mycobacterial infections are considered to a serious challenge of medicine, and the emergence of MDR and XDR tuberculosis is a serious public health problem. Tuberculosis can cause high morbidity and mortality around the world, particularly in developing countries. The emergence of drug-resistant Mycobacterium infection following limited therapeutic technologies coupled with the serious worldwide tuberculosis epidemic has adversely affected control programs, thus necessitating the study of the role bacteriophages in the treatment of mycobacterial infection. Bacteriophages are viruses that are isolated from several ecological specimens and do not exert adverse effects on patients. Phage therapy can be considered as a significant alternative to antibiotics for treating MDR and XDR mycobacterial infections. The useful ability of bacteriophages to kill Mycobacterium spp has been explored by numerous research studies that have attempted to investigate the phage therapy as a novel therapeutic/diagnosis approach to mycobacterial infections. However, there are restricted data about phage therapy for treating mycobacterial infections. This review presents comprehensive data about phage therapy in the treatment of mycobacterial infection, specifically tuberculosis disease.

Ecology of Anti-Biofilm Agents II: Bacteriophage Exploitation and Biocontrol of Biofilm Bacteria

Bacteriophages are the viruses of bacteria. In the guise of phage therapy they have been used for decades to successfully treat what are probable biofilm-containing chronic bacterial infections. More recently, phage treatment or biocontrol of biofilm bacteria has been brought back to the laboratory for more rigorous assessment as well as towards the use of phages to combat environmental biofilms, ones other than those directly associated with bacterial infections. Considered in a companion article is the inherent ecological utility of bacteriophages versus antibiotics as anti-biofilm agents. Discussed here is a model for phage ecological interaction with bacteria as they may occur across biofilm-containing ecosystems. Specifically, to the extent that individual bacterial types are not highly abundant within biofilm-containing environments, then phage exploitation of those bacteria may represent a "Feast-or-famine" existence in which infection of highly localized concentrations of phage-sensitive bacteria alternate with treacherous searches by the resulting phage progeny virions for new concentrations of phage-sensitive bacteria to infect. An updated synopsis of the literature concerning laboratory testing of phage use to combat bacterial biofilms is then provided along with tips on how "Ecologically" such phage-mediated biofilm control can be modified to more reliably achieve anti-biofilm efficacy.

Biofilm growth on implants: bacteria prefer plasma coats

PURPOSE

Bacterial biofilm formation on prostheses or devices used for osteosynthesis is increasingly recognized as cause of persistent infections, an entity known as implant-associated posttraumatic osteomyelitis. Biofilm formation is a very complex, multistep process with adhesion as the first and decisive step. The most prevalent pathogens found are staphylococci species, especially S. aureus, presumably due to a preference to non-biological materials, such as metal. Adherence is influenced by several factors, including the microenvironment, in which blood proteins from serum or plasma might influence adhesion and maybe biofilm formation. The aim of the present study was to test and to compare adherence of S. aureus and P. aeruginosa to different biological and non-biological surfaces in vitro. The question was addressed if coating of the surface by plasma or serum proteins influences bacterial adherence.

METHODS

Adherence of radiolabeled bacteria to different surfaces in the presence or absence or serum/plasma proteins was measured over time.

RESULTS

When testing adherence of S. aureus to plastic, titanium or to monolayers of epithelial cells (A549) or fibroblasts (Colo800) a clear-cut preference for non-biological surfaces, especially for titanium was seen. Using P. aeruginosa species a similar pattern without a significant difference was revealed. When mimicking the in vivo situation by pre-coating of titanium with human serum or plasma adherence was increased, especially when titanium was coated ("opsonized") by plasma.

CONCLUSIONS

Bacterial adherence to surfaces is determined by a variety of factors such as temperature, the presence of nutrients, the absence of host defense systems and the configuration of the covered surface. In vivo, adherence to non-biological surfaces is also influenced by the microenvironment, especially plasma proteins, promoting biofilm formation.