Objectives: This study was conducted to detect the biofilm formation in bacterial isolates from chronic wound infections.
Materials and Methods: In the present study, ninety two isolates from chronic wound infections were identified by MALDI-TOF-MS (bioMerieux) and VITEK-2-MS (bioMerieux). These isolates were further screened for biofilm formation by three methods i. e., Tissue Culture Plate method (TCP), Tube Method (TM) and Congo Red Agar (CRA) method. Impact of biofilm production was correlated with the antibiotic resistant pattern.
Statistical Analysis: Statistical analysis was done for all three methods considering TCP as Gold Standard and parameters like senitivity and specificity of TM i.e. 47.2 and 100% respectively.
Results: Out of 92 isolates, biofilm formation was seen in 72 isolates (78.2%) by TCP method. 64 isolates were strong biofilm producers, 8 isolates were moderate biofilm producers and 20 isolates were nonbiofilm producing. High prevalence of biofilm formation was seen in nonhealing ulcers infected with Staphylococcus aureus followed by Klebsiella pneumoniae.
Conclusion: Among three screening methods used for detection of biofilm production, TCP method is considered to be a standard and most reliable for screening of biofilm formation in comparison to TM and CRA.
Objectives: This study aimed to: (i) evaluate the effects of Malaysian Trigona honey on bacterial structure and (ii) assess the anti-virulence potential of this honey by examining their impacts on the expression of selected genes (involved in stress survival and biofilm formation) in a test organism.
Materials and Methods: Trigona honey's impacts on the bacterial structure (cell morphology) and the expression profiles of select Pseudomonas Aeruginosa and Streptococcus Pyogenes genes were examined using scanning electron microscopy (SEM) and real-time PCR (RT-qPCR) analysis, respectively.
Results: SEM showed that the decreased cell density deformed, disrupted, and damaged cells for both bacteria. RT-qPCR showed that the expression of fleN, fleQ, and fleR genes of P.aeruginosa were decreased, 4.26-fold, 3.80-fold and 2.66- fold respectively. In addition, scpA, ftsY, and emm13 of S.pyogenes were decreased, 2.87-fold, 3.24-fold, and 4.65-fold respectively.
Conclusion: Our results indicate that Trigona honey may be an effective inhibitor and virulence modulator of P. aeruginosa and S. pyogenes via multiple molecular targets. This deduction needs to be investigated in vivo.
Aims: The objective of this study is to investigate if the subgingival plaque biofilm resistance can be reduced using doxycycline in the presence of low-intensity electric field (bioelectric effect).
Settings and Design: The study was an in vitro microbiological study.
Materials and Methods: Subgingival plaque samples from chronic periodontitis patients were collected to grow subgingival plaque biofilms on hydroxyapatite disks. Hydroxyapatite disks with the plaque biofilms from each patient were divided into four groups: (i) No intervention - control, (ii) current alone - CU; (iii) doxycycline - AB, and (iv) combined treatment - CU + AB. After respective treatments, the disks were anaerobically incubated for 48 h, the biofilm was dispersed and subcultured and colony-forming unit/mL was estimated in all the four groups.
Statistical Analysis: Statistical analysis was done using Mann-Whitney and Kruskal-Wallis tests for intergroup comparisons. T-test was done to assess the difference in current flow between the groups CU and CU + AB.
Results: All the three treatment modalities showed antibacterial effect. Application of current alone resulted in reduced bacterial growth than control group. Doxycycline alone resulted in reduction in bacterial counts better than control and current alone groups. The combination treatment showed greatest inhibition of bacterial colonies.
Conclusion: The ability of doxycycline antibiotic in inhibiting plaque biofilm was significantly enhanced by application of a weak electric field (5 volts for 2 min).
METHODS: Antibiotics susceptibility testing, detection of OXAs genes and the biofilm-producing capacity were performed using the Kirby Bauer method, polymerase chain reaction (PCR) and adherence quantitative assays, respectively.
RESULTS: A total of 80 A. baumannii isolates were mainly obtained from sputum and most of them were resistant to antibiotics. All A. baumannii carried blaOXA-51 gene, yet no blaOXA-24 and blaOXA-58 genes were detected. Fourteen (82.4%) of the 17 meropenem resistant isolates carried blaOXA-23 gene, but it was not found in meropenem sensitive isolates. In addition, sixty (75.0%) of 80 isolates were biofilm producers with 2 (2.5%), 16 (20.0%), and 42 (52.5%) isolates were identified as strong, moderate and weak biofilm producers, respectively.
CONCLUSION: Most of A. baumannii isolates had a high level of antibiotic resistance and had a capacity to produce biofilm.
MATERIALS AND METHODS: An estimated 120 human root dentin disks were prepared, sterilized, and inoculated with E. faecalis strain (ATCC 29212) to develop a 3-weeks-old biofilm. The dentin discs were exposed to group I-control group: 5.25% sodium hypochlorite (NaOCl) (n = 20); group II-1% ALX + 5.25% NaOCl (n = 40); group III-1% alexidine (ALX) (n = 40) (Sigma-Aldrich, Mumbai, India); group IV-negative control: saline (n = 20). After exposure, the dentin disks were stained with the fluorescent live/dead dye and evaluated with a confocal scanning electron microscope to calculate the proportion of dead cells. Statistical analysis was done using the Kruskal-Wallis and Mann-Whitney U test (p < 0.05).
RESULTS: The maximum proportion of dead cells were seen in the groups treated with the combination of 1% ALX + 5.25% NaOCl (94.89%) and in the control group 5.25% NaOCl (93.14%). The proportion of dead cells presented in the 1% ALX group (51.79%) and negative control group saline (15.10%) were comparatively less.
CONCLUSION: The antibacterial efficiency of a combination of 1% ALX and 5.25% NaOCl was more effective when compared with 1% ALX alone.
CLINICAL SIGNIFICANCE: Alexidine at 1% could be used as an alternative endodontic irrigant to chlorhexidine, as alexidine does not form any toxic precipitates with sodium hypochlorite. The disinfection regimen comprising a combination of 1% ALX and 5.25% NaOCl is effective in eliminating E. faecalis biofilms.