In vitro anti-biofilm and anti-bacterial activity of Junceella juncea for its biomedical application

Objective:To investigate the anti-biofilm and anti-bacterial activity of Junceella juncea(J.juncea)against biofilm forming pathogenic strains.Methods:Gorgonians were extraeted with methanol and analysed with fourier transform infrared spectroscopy.Biofilm forming pathogens were identified by Congo red agar supplemented with sucrose.A quantitative spectrophotometric method was used to monitor in vitro biofilm reduction by microtitre plate assay.Anti-bacterial activity of methanolic gorgonian extract(MGE)was carried out by disc diffusion method followed by calculating the percentage of increase with crude methanol(CM).Results:The presence of active functional group was exemplified by FT-IR spectroscopy.Dry,black,crystalline colonies confirm the production of extracellular polymeric substances responsible for biofilm formation in Congo red agar.MGE exhibited potential anti-biofilm activity against all tested bacterial strains.The anti-bacterial activity of methanolic extract was comparably higher in Salmonella typhii followed by Escherichia colt,Vibrio cholerae and Shigella flexneri.The overall percentage of increase was higher by 50.2%to CM.Conclusions:To conclude,anti-biofilm and anti-bacterial efficacy of J.juncea is impressive over biofilm producing pathogens and are good source for novel anti-bacterial compounds.

MBDS Solvent: An Improved Method for Assessment of Biofilms

Biofilms are recognised as an important contributor to bacterial resistance towards traditional antimicrobial treatments. Assessment of biofilm formation currently relies on a 96 well microtitre plate assay, which usually involves the colourimetric detection of stain (typically crystal violet) removed from previously stained biofilm. The amount of crystal violet released is then used as a quantitative indicator of the amount of biofilm formed. Currently, this is achieved by solubilisation of the stain by ethanol which results in partial decolourisation of the crystal violet stained biofilm which impacts the accuracy and reproducibility of this method. Herein, we describe a modified biofilm dissolving solution (MBDS) which produces a more uniform and reproducible colour release from stained biofilm through solubilisation of the biofilm architecture itself. Here we use crystal violet stained biofilms of P. aeruginosa strain PA0-1, to demonstrate an approximate two fold increase in crystal violet release by MBDS, as compared to ethanol treatment. In addition, when ethanol decolourised biofilms were treated again with MBDS, an almost equal amount of remnant crystal violet was recovered by dissolving the biofilm and the stain trapped within it. These results were reflected in microscopic analysis of ethanol treated and MBDS treated biofilm. Similar results were obtained when MBDS was used to decolourise and dissolve the biofilms of a number of other bacterial species highlighting the advantages of MDBS as a universal solvent for the colour detection of biofilm.

Molecular Detection of Biofilm-Producing <i>Staphylococcus aureus</i>Isolates from National Orthopaedic Hospital Dala, Kano State, Nigeria

This study evaluated biofilm formation and antibiotic susceptibility in 36 clinical S. aureus isolates recovered from orthopaedic patients and detected the presence of intercellular adhesion and adhesin genes. Staphylococcus aureus was isolated from nasal swab, wound and urine specimens collected from orthopaedic patients in National Orthopaedic Hospital Dala, Kano over a period of three months. The isolates were identified using rapid identification kit for Staphylococcus species. The antibiotics susceptibility of the isolates was determined using modified disc diffusion method. Phenotypically, the biofilm formation was assessed using the Congo red agar method and microtitre plate assay. Polymerase chain reaction (PCR) analysis was used to detect biofilm-associated genes and characterize the isolates. The isolation rate of S. aureus from the samples (n = 134) was 26.8%, mainly from nasal swab (36%) and wound swab (36%). A total of 19 (52.7%) of the isolates showed positive for slime production. Majority of the isolates 29/36 (81.6%) were biofilm positive with only 2 (5.5%) and 5 (13.8%) as strong biofilm-formers and moderate biofilm-formers respectively. Molecular evaluation of the biofilm-associated genes in 12 S. aureus isolates revealed the prevalence of bbp genes (25%), clfA genes (16.6%) and the icaA (8.3%). None of the isolates harboured the fnbA and cna genes. There is no significant difference (P > 0.05) in the antibiotic resistance pattern between biofilm-positive and biofilm-negative S. aureus isolates. This result revealed that phenotypically most of the S. aureus isolates were biofilm formers but few of them chromosomally harbour the biofilm-associated genes.