Abstract
Biofilm represents a protected mode, which allows bacteria to survive and proliferate in a hostile environment. Little is known whether the ability to form biofilms is a characteristic of all groups of A streptococcal (GAS) strains and whether there is a relationship between biofilm formation and a clinical source of isolates. A capsule physically covers superficial adhesins and other proteins, essential in bacterial attachment, as the first step in biofilm formation. It is also possible that hyaluronic acid could form part of the complex extracellular polymer matrix of biofilms and contribute to the three-dimensional architecture of the biofilm. The aim of this study was to investigate if there are differences in adherence and biofilm production between GAS strains with different pathogenic potential, and the possible role of the capsule in this process. A total of 122 isolates were divided into three groups: noninvasive (NI), low invasive (LI) and highly invasive (HI). Adherence, SpeB and biofilm production were tested before and after hyaluronidase treatment. There was no difference in adherence between untreated GAS strains, but after capsule removal, NI and HI isolates adhered significantly better than the LI group. Before treatment, isolates of the HI group were the worst biofilm producers, but after capsule removal, they became the best biofilm producers. There was no difference in SpeB production among GAS isolates, regardless of the hyaluronidase treatment.
Highlights
Biofilm is a microbially derived sessile community characterized by cells that are irreversibly attached to a substratum and embedded in a matrix of extracellular polymeric substances (Donlan and Costerton, 2002)
A total of 172 Streptococcus pyogenes isolates used for biofilm testing were divided into three groups: (1) a noninvasive group (NI) obtained from carriers (100 isolates); (2) a low invasive group (LI) isolated from patients with tonsillopharyngitis (50 isolates), and (3) a highly invasive (HI) group (22 isolates), isolated from the blood of patients with sepsis and necrotizing fasciitis obtained from the collection of the Institute of Microbiology and Immunology, School of Medicine, Belgrade
There was no difference in biofilm production among all the groups of A streptococcal (GAS) strains after 12 h of incubation (p=0.262)
Summary
Biofilm is a microbially derived sessile community characterized by cells that are irreversibly attached to a substratum and embedded in a matrix of extracellular polymeric substances (Donlan and Costerton, 2002). Biofilm represents a protected mode, which allows bacteria to survive and proliferate in a hostile environment. Its structure allows sufficient nutrients to sustain growth and, at the same time, protect the bacteria from toxic compounds and reagents present in the environment. (Costerton et al, 1999). Many pathogenic and nosocomial bacteria with the ability to form biofilms are responsible for acute and chronic infections It has been estimated by the National Institute of Health (United States) that more than 80% of persistent bacterial infections are likely to involve biofilms (Bjarnsholt et al, 2002) Examples of typical biofilm-associated diseases are caries, gingivitis, periodontitis, endocarditis and prostatitis. Such infections are extremely difficult to eradicate because of the resistance of biofilm to numerous antimicrobial agents and products of the immune sys-
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
