Ethel Suman

Effect of fluoride varnish and chlorhexidine-thymol varnish on mutans streptococci levels in human dental plaque: a double-blinded randomized controlled trial.

BACKGROUND Recent systematic reviews on clinical trials comparing the efficacy of chlorhexidine and fluoride varnish found that the evidence was inconclusive and further well-conducted randomized controlled clinical trials were advocated. AIM To compare the effect of fluoride varnish (F) and Chlorhexidine-thymol varnish (CHX/T) with intensive application regimen on mutans streptococci (MS) levels in human dental plaque. DESIGN Seventy-five subjects between 6 and 10 years of age were allocated into three groups: Group 1-F varnish (n = 29); Group 2-CHX/T varnish(n = 29); Group 3-placebo varnish (n = 17) by stratified block randomization. After baseline plaque samples were obtained, varnish application was applied and repeated at an interval of 3 days in each group. Plaque samples were repeated at 48 h, 1 month, and 3 months. The samples were spread over mitis-salivarius-bacitracin (MSB) culture media, and the colony-forming units per ml (CFU) were measured. RESULTS In both Groups 1 and 2, Wilcoxon matched-pairs signed-rank test revealed significant differences in log CFU values of MS between baseline and 48 h, baseline and 1 month but no significant difference between baseline and 3 months. An intergroup comparison at different time intervals showed that the difference between three groups was statistically insignificant. CONCLUSION F varnish and CHX/T varnish, with an intensive regimen application have equivocal effect on MS levels in dental plaque.

Role of bacterial biofilms in chronic non-healing ulcers and effect of subinhibitory concentrations of Betadine and hydrogen peroxide on biofilms.

a subinhibitory concentration of vancomycin (Z 1⁄4 3.408; P 1⁄4 0.001). There was also a significant correlation between the adherence of bacteria to catheter and cannula with biofilm production (P 1⁄4 0.002). Our study found that the subinhibitory concentration of vancomycin caused a significant decrease in adherence of bacteria to catheter and cannula material and these organisms also exhibited a significant decrease in biofilm formation. Vancomycin, the treatment of choice in many meticillin-resistant staphylococcal infections, has been proposed in combination for the treatment of Staphylococcus epidermidis infection. The results of our study show that the use of vancomycin has an added advantage of preventing the initial adherence of bacteria to prosthetic devices and thereby preventing biofilm formation.

Does vancomycin inhibit biofilm production by coagulase-negative staphylococci?

4. Gonzalez C, Rubio M, Romer-Vivas J, Gonzalez M, Picazo JJ. Bacteraemic pneumonia due to Staphylococcus aureus: a comparison of disease caused by methicillin-resistant and methicillin-susceptible organisms. Clin Infect Dis 1999;29: 1171e1177. 5. Hospital Infection Control Practices Advisory Committee. Recommendations for preventing the spread of vancomycin resistance. Infect Control Hosp Epidemiol 1995;16:105e113. 6. Cookson BD, Macrae MB, Barrett SP, et al. Guidelines for the control of glycopeptide-resistant enterococci. J Hosp Infect 2006;62:6e21. 7. Zvonar R, Natarajan S, Edwards C, Roth V. Assessment of vancomycin use in chronic haemodialysis patients: room for improvement. Nephrol Dial Transplant 2008;23:3690e3695.

Anti-biofilm and anti-adherence activity of Glm-U inhibitors.

BACKGROUND Intravascular catheters and urinary catheters are an important source of hospital-acquired infections. Many microorganisms colonize indwelling catheters, including central venous catheters (CVCs) forming biofilms and cause infections that are difficult to treat. Although various methods have been employed to reduce biofilms, enzymes involved in bacterial cell wall synthesis could provide novel targets for the development of anti-biofilm agents. N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU) is an essential enzyme in aminosugars metabolism and catalyzes the formation of uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc), an important precursor in the peptidoglycan and lipopolysaccharide biosynthesis of Gram-positive and Gram-negative bacteria. Previous study has been conducted on the anti-biofilm effect of GlmU inhibitors such as N-ethyl maleimide (NEM) and NEM analogs along with a cationic polypeptide protamine sulfate (PS), which enhanced its anti-biofilm activity. AIM The present study aimed at finding the effect of sub-inhibitory concentrations of N-ethyl maleimide (NEM) and protamine sulfate (PS) on the biofilms produced by Pseudomonas aeruginosa and Enterococcus spp. isolated from cases of catheter-associated UTI as well as Klebsiella pneumoniae and Staphylococcus aureus isolated from cases of catheter-related bloodstream infections (CRBSI). MATERIALS AND METHODS In order to enhance the activity of NEM and to develop a broad-spectrum anti-microbial composition, NEM (50 μg/ml) was combined with protamine sulfate (50 μg/ml) and tested for anti-biofilm activity using a standard quantitative biofilm assay method. RESULTS AND CONCLUSION It was observed that NEM had no effect on the biofilm produced by Pseudomonas aeruginosa as well as by Enterococcus spp. NEM also caused a significant decrease in biofilm production by Staphylococcus aureus while it had no effect on the biofilm produced by Klebsiella pneumoniae. There was a significant synergistic inhibitory effect on Staphylococcus aureus and Enterococcus spp., whereas Pseudomonas aeruginosa and Klebsiella pneumoniae remained unaffected. Combination of GlmU inhibitor-plus-protamine sulfate failed to significantly reduce bacterial adherence of Pseudomonas aeruginosa and Klebsiella pneumoniae to catheter and cannula pieces, respectively. We found that the GlmU inhibitor was mainly effective in preventing the adherence and biofilm formation by gram-positive organisms. The combination of NEM and protamine sulfate may, therefore, be tried as anti-infective coatings for medical devices such as catheters and cannulas, and thus help in overcoming microbial resistance in the current era of increasing device-associated hospital infections.

Evaluation of conventional, protaper hand and protaper rotary instrumentation system for apical extrusion of debris, irrigants and bacteria- An in vitro randomized trial

Background Endodontic instrumentation carries the risk of over extrusion of debris and bacteria. The technique used and the type of instrumentation influences this risk. Aim The purpose of this study was to evaluate and compare the K-file, ProTaper hand and ProTaper rotary instrumentation systems for the amount of apically extruded debris, irrigant solution and intracanal bacteria. Design Experimental single blinded randomized type of in vitro study with sample of 30 single rooted teeth. Endodontic access cavities were prepared and the root canals were filled with the suspension of E. faecalis. Myers and Montogomery Model was used to collect apically extruded debris and irrigant. Canals were prepared using K files, Hand protapers and Protaper rotary files. Statistical analysis Non Parametric test like Kruskal-Wallis and Mann-Whitney U test were applied to determine the significant differences among the group. Results Tests revealed statistically significant difference between the amount of debris and number of bacteria extruded by the ProTaper hand and the K-files. No statistically significant difference was observed between the amounts of irrigant extruded by the ProTaper hand and the K-file system. Statistically significant differences were observed between the amounts of bacteria and irrigant extruded by the ProTaper rotary and the Protaper hand. No statistically significant difference was observed between the amounts of debris extruded by the ProTaper hand and the K-file system. Conclusions Amount of apical extrusion of irrigant solution, bacteria and debris are significantly greater with K File instruments and least with Protaper rotary instruments. Key words:Protaper, rotary, periapical extrusion.

Fungal spores and fruiting bodies in cervicovaginal smears: Contaminant or infection?

Contaminants from various sources are curious findings in cervicovaginal smears and pose diagnostic challenges especially when they need to be distinguished from pathogens. Candidiasis is the most frequently encountered fungal infection but fungal contaminants are relatively common. Detection of fruiting bodies and spores of Aspergillus species is uncommon and may represent either a true infection or contamination. This study was undertaken to evaluate the presence of fungal spores, hyphae, and fruiting bodies in routine cervical smears and distinguish a true infection from contamination.

In vitro evaluation of sealing ability and antimicrobial activity of hydraulic temporary sealing materials

Context: A good seal ability and antimicrobial action is a desired feature of an effective temporary sealing material. Aims: To compare the sealing ability and antimicrobial activity of three temporary sealing materials: Caviton, MD Temp and IRM Materials and Methods: In the present in vitro study, sealing ability (dye penetration method using 2% methylene blue) was measured with class I cavities on human premolars restored using test materials. The antimicrobial activity (agar diffusion test) of the materials was evaluated against Streptococcus mutans (MTCC 497 and clinical isolate) and Candida albicans (ATCC 60193 and clinical isolate). Statistical Analysis Used: For sealing ability, data was statistically analyzed using Chi-square test at a significance level of 5% using Statistical Package for Social Sciences (SPSS) 15.0. Antimicrobial activity was evaluated by comparing the mean diameter of the inhibition zones formed around the respective wells. Results: IRM produced best marginal sealing (Fisher′s exact test = 38.361 and P < 0.001) and was also associated with higher antimicrobial activity in comparison to Caviton and MD Temp. The inferior properties of MD temp can be attributed to thermal instability demonstrated by MD Temp leading to an inadequate seal, and also failed to produce a zone of inhibition. IRM proved effective and superior to Caviton and MD Temp in both these aspects. Conclusions: The success of an endodontic treatment depends on the effective seal achieved following debridement. This study stresses the need for an adequate marginal seal along with satisfactory antibacterial potential for a temporary sealing material.