Comparative Evaluation of Antibacterial and Anti-Adherent Properties between Titanium Oxide, Silver Dioxide-Coated, and Conventional Orthodontic Wires Against Streptococcus Sanguis Causing Gingivitis.

Objective: To compare the antibacterial and anti-adherent properties of conventional stainless steel (SS) orthodontic wires and surface-modified silver dioxide-coated and titanium oxide-coated SS orthodontic wires against Streptococcus sanguis causing gingivitis. Materials and Methods: The study used 60 orthodontic SS wire specimens, organized into six groups of ten each. The control group had uncoated wires, and the experimental group featured wires coated with silver dioxide and titanium oxide. Surface modification was done using DC sputtering, and microbiological tests assessed the antibacterial and anti-adherent properties of the AgO2- and TiO2-coated wires. Results: This study demonstrated the antibacterial effect against S. sanguis in orthodontic wires coated with the photocatalytic AgO2 and TiO2 compared to the uncoated wires. Also, this study demonstrated an anti-adherent effect in the AgO2- and TiO2-coated orthodontic wires. Moreover, the bacterial accumulation on orthodontic wires coated with AgO2 and TiO2 was lower compared to that on the uncoated wires. Conclusion: During orthodontic treatment, the formation of dental plaque can be prevented by coating the surface of stainless-steel orthodontic wires with photocatalytic AgO2 and TiO2. Compared to silver dioxide, the titanium oxide-coated SS orthodontic wires showed better antibacterial and anti-adherent properties.

A Comparative Analysis of Bacterial Adhesion on Different Long-Term Provisional Fixed Prostheses Fabricated by CAD/CAM Milling, 3D Printing, and Heat Cure Technique: An In Vivo Study.

Objectives: This study compares the bacterial susceptibility to three different provisional restorations manufactured with different laboratory techniques, i.e., heat cure, CAD/CAM, and 3D printing. Materials and Methods: Totally, 45 health patients with age group of 30-60 years undergoing complete veneer crown treatment were selected for the study and divided into three groups with 15 samples in each as Group I: the crowns were made from polymethyl methacrylate polymer fabricated by the conventional heat cure method, Group 2: the crowns were made from polymethyl methacrylate fabricated by subtractive manufacturing CAD/CAM method, and Group 3: the crowns were made from oligomers fabricated by additive manufacturing 3D printing. The samples were examined for bacterial adherence at scanning electron microscope. The colony-forming units (CFUs) were calculated, and statistically analyzed. Results: It has been determined that the digitally fabricated provisional restorations prove to be superior in terms of surface topography than to the conventionally fabricated provisional restorations. Conclusion: The study concludes that 3D-printed provisional restorations are more precise with reduced bacterial susceptibility than milled ones.

Prevalence of salivary microbial load and lactic acid presence in diabetic and non-diabetic individuals with different dental caries stages.

Objectives: This study aims to correlate caries-causing microorganism load, lactic acid estimation, and blood groups to high caries risk in diabetic and non-diabetic individuals and low caries risk in healthy individuals. Materials and Methods: This study includes 30 participants divided into 3 groups: Group A, High-risk caries diabetic individuals; Group B, High-risk caries non-diabetic individuals; and Group C, Low-risk caries individuals. The medical condition, oral hygiene, and caries risk assessment (American Dental Association classification and International Caries Detection and Assessment System scoring) were documented. Each individual's 3 mL of saliva was analyzed for microbial load and lactic acid as follows: Part I: 2 mL for microbial quantity estimation using nutrient agar and blood agar medium, biochemical investigation, and carbohydrate fermentation tests; Part II: 0.5 mL for lactic acid estimation using spectrophotometric analysis. Among the selected individuals, blood group correlation was assessed. The χ2 test, Kruskal-Wallis test, and post hoc analysis were done using Dunn's test (p < 0.05). Results: Group A had the highest microbial load and lactic acid concentration, followed by Groups B and C. The predominant bacteria were Lactobacilli (63.00 ± 15.49) and Streptococcus mutans (76.00 ± 13.90) in saliva. Blood Group B is prevalent in diabetic and non-diabetic high-risk caries patients but statistically insignificant. Conclusions: Diabetic individuals are more susceptible to dental caries due to high microbial loads and increased lactic acid production. These factors also lower the executing tendency of neutrophils, which accelerates microbial accumulation and increases the risk of caries in diabetic individuals.

In vitro evaluation of antimicrobial efficacy of silver zeolite against common oral pathogens.

Objectives: Antimicrobial efficacy and toxicity analysis of 5 different concentrations of silver zeolite (SZ) compound against 5 common oral pathogens Streptococcus mutans, Streptococcus pyogenes, Lactobacillus sp., Staphylococcus aureus, Candida albicans. Material and methods: The antimicrobial efficacy of 5 different concentrations of SZ was tested against 5 common oral pathogens using the agar well diffusion method and the MIC and MBC values were determined using the micro broth dilution method. The toxicity of all 5 different concentrations was evaluated using brine shrimp assay and lethal concentration (Lc50) value was determined. Results: At 10 µg/mL the antimicrobial activity of SZ was almost negligible. The antimicrobial activity was observed in an increasing trend against all the test microorganisms as the concentration increased. At 75 & 100 µg/mL the zone of inhibitions was more than the control. Furthermore, MIC and MBC values of SZ with concentrations 25, 50, 75, and 100 µg/mL were determined and recorded. SZ was equally effective against all the test organisms. The LC25 (lethal concentration25) value was 1.6 µg/mL, whereas the LC50 value was 1.77 µg/mL and the LC75 value was 1.90 µg/mL, calculated from the probit computational method. Conclusion: SZ has the potential to change the ongoing system and bring about a revolution as an antimicrobial drug. However, the dose must be regulated as it can be toxic in higher concentrations. SZ compounds with the correct study of physicochemical properties and toxicity analysis can increase their pharmacological use and market value.

Oral Biofilm: Development Mechanism, Multidrug Resistance, and Their Effective Management with Novel Techniques.

Biofilms are formed by the congregation of one or more types of microorganisms that can grow on a firm surface. Dental plaque is one of the most commonly forming biofilms in the oral cavity and appears as a slimy layer on the surface of the teeth. In general, the formation is slow, but biofilms are very adaptive to the changing environment, and a mature biofilm can cause many health-related problems in humans. These biofilms remain unaffected by antibiotics as they do not allow the penetration of antibiotics. Moreover, the increased level of virulence and antibiotic resistance of microorganisms in the oral biofilm or dental plaque has made its clinical management a serious challenge worldwide. Chlorhexidine-like antimicrobial drugs have been partially effective in removing such organisms; however, the precise and continuous elimination of these microorganisms without disturbing the normal microbial flora of the oral cavity is still a challenge. This review paper focuses on the process of oral biofilm formation, related complications, development of drug-resistant bacteria in these biofilms, and their effective management by the use of different novel techniques, available from various published research and review articles.

Probiotics-A complete oral healthcare package.

Probiotics are living bacterial cells that have significant therapeutic potential for treating human infectious diseases. There is a huge market for probiotics in the pharmaceutical sector. They have been frequently used to treat the gastrointestinal diseases and improve gut immunity. In this review, the strains currently in use for manufacturing oral probiotic formulations are discussed. The review further recommends the use of probiotics for the control of various oral health disorders, like dental caries, periodontitis, gingivitis, halitosis, burning mouth syndrome, and oral cancer. Finally, this review also explores the use of various commercial probiotic products in maintaining oral health, their market values, and government acts and regulations that are relevant to the production and marketing of probiotics. Probiotics have tremendous therapeutic potential and more in-depth research must be done on these beneficial bacteria to make them one of the leading drugs in treating oral disorders.

Corrigendum to "Statistical Evaluation of Two Microbiological Diagnostic Methods of Pulmonary Tuberculosis After Implementation of a Directly Observed Treatment Short-course Program" [Osong Public Health Res Perspect 2013;4(1):45-51].

[This corrects the article on p. 45 in vol. 4, PMID: 24159529.].

Prevalence of methicillin resistant staphylococcus aureus isolated from saliva samples of patients with oral squamous cell carcinoma / revalencia de Staphylococcus aureus resistente a la meticilina en muestras de saliva de pacientes con carcinoma oral de células escamosas

Objectives: To study the prevalence of methicillin resistant Staphylococcus aureus (MRSA) in saliva samples of pre-surgical oral squamous cell carcinoma (OSCC) patients along with their resistance pattern to other antibiotics. Methods: Saliva samples of OSCC patients were collected and processed for isolation of MRSA. Staphylococcus aureus isolates were primarily identified using standard microbiological methods like biochemical assays, specialized media and latex agglutination test. Confirmation of MRSA strains was done by growing the isolates on MRSA agar and by using PCR to amplify two MRSA specific genes. All the isolated Staphylococcus aureus strains were subjected to antibiotic sensitivity tests. Results: A total of 17 Staphylococcus aureus strains were isolated from 50 saliva samples of pre-surgical OSCC patients of which 13 were confirmed to be MRSA. These MRSA strains were also found to be mostly resistant to other commonly used antibiotics. Univariate analysis revealed that most patients with MRSA infections had a prior history of hospitalization and surgery. Also, it was confirmed that patients with other comorbidities and infections were more prone to having MRSA present in the saliva. Conclusion: The majority of Staphylococcus aureus isolates from the saliva of OSCC patients were MRSA, and were resistant to several other commonly used antibiotics.

Objetivos: Estudiar la prevalencia de Staphylococcus aureus resistente a la meticilina (MRSA) en muestras de saliva prequirúrgicas de pacientes con carcinoma oral de células escamosas (COCE) junto con su patrón de resistencia a otros antibióticos. Métodos: Se recolectaron muestras de saliva de pacientes con COCE y se procesaron para el aislamiento de SARM. Los aislamientos de Staphylococcus aureus se identificaron principalmente mediante métodos microbiológicos estándar, como los análisis bioquímicos, los medios especializados y la prueba de aglutinación con látex. La confirmación de las cepas de SARM se realizó cultivando los aislados en agar SARM y utilizando PCR para amplificar dos genes específicos de SARM. Todas las cepas aisladas de Staphylococcus aureus se sometieron a pruebas de sensibilidad a los antibióticos. Resultados: Se aislaron un total de 17 cepas de Staphylococcus aureus a partir de 50 muestras de saliva de pacientes prequirúrgicos con COCE, de los cuales solo se confirmó que 13 eran SARM. También se encontró que estas cepas de SARM son resistentes a otros antibióticos de uso común. El análisis univariado reveló que la mayoría de los pacientes con infecciones por SARM tenían antecedentes previos de hospitalización y cirugía. Además, se confirmó que los pacientes con otras comorbilidades e infecciones eran más propensos a las infecciones por SARM. Conclusión: la mayoría de los aislamientos de Staphylococcus aureusde la saliva de los pacientes con OSCC fueron MRSA y fueron resistentes a varios otros antibióticos de uso común.

Antibacterial efficacy of five medicinal plants against multidrug-resistant enteropathogenic bacteria infecting under-5 hospitalized children.

OBJECTIVE: To evaluate in vitro antibacterial effectiveness of five medicinal plants used by an Indian aborigine, against 8 multidrug-resistant (MDR) enteropathogenic bacteria isolated from clinical samples of under-5 hospitalized children. METHODS: Antibiotic sensitivity patterns of eight clinically isolated strains of enteropathogenic bacteria, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Salmonella paratyphi, S. typhi, Shigella dysenteriae, S. sonnei and Vibrio cholerae were assessed by disc-diffusion method. Antibacterial activities of 8 solvent-extracts of leaves and bark of five medicinal plants were monitored by the agar-well diffusion method. The microbroth dilution method was used to assess minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Qualitative phytochemical analyses of active plant extracts were carried out. RESULTS: Ethanol, ethyl acetate and methanol extracts of Holarrhena antidysenterica leaf tissue were most effective against 8 MDR pathogens in vitro. Similarly, acetone, ethanol and methanol extracts of Terminalia alata leaf tissue; chloroform, ethyl acetate and methanol extracts of Terminalia arjuna leaf tissue and ethyl acetate, ethanol and methanol extracts of Paederia foetida leaf tissue were most effective in inhibiting in vitro growth of the 8 MDR enteropathogens. Ethyl acetate and methanol extracts of H. antidysenterica bark tissue; acetone, ethanol and methanol extracts of T. alata bark tissue and acetone, ethanol and methanol extracts of T. arjuna bark tissue were most effective in controlling enteropathogen growth. The minimum inhibitory concentration and minimum bactericidal concentration values of the 3 most antimicrobial leaf and bark extracts from the five plants were in the range of 1.56 to 50 mg/mL. CONCLUSION: These 5 plants exhibited in vitro control over a cohort of 8 enteropathogenic bacterial strains isolated from clinical samples.

Prevalence of two multidrug-resistant Klebsiella species in an Indian teaching hospital and adjoining community.

BACKGROUND: The Gram-negative pathogenic bacteria Klebsiella oxytoca and Klebsiella pneumoniae produce the extended spectrum ß-lactamase (ESBL) and cephalosporinase enzymes and are the major causes of hospital acquired (HA) infections and epidemics in non-hygienic communities in the majority of developing countries. METHODS: The prevalence of multidrug resistance among 445 strains of K. oxytoca and K. pneumoniae isolated from clinical samples of patients with gastrointestinal infections over a period of 42 months in the hospital was recorded, along with the sensitivity patterns to 23 antibiotics, including third-generation cephalosporin and fluoroquinolone antibiotics, using the disk-diffusion method. RESULTS: Of 175 K. oxytoca isolates, 143 were ESBL positive and 117 were fluoroquinolone resistant. Of 270 K. pneumoniae isolates, 200 were ESBL positive and 195 were independently fluoroquinolone resistant. The HA samples yielded more isolates than the community acquired (CA) samples for each species. The K. oxytoca strains were resistant to cefepime, gatifloxacin, ciprofloxacin, ceftazidime, levofloxacin and imipenem, whereas the K. pneumoniae strains were highly resistant to ampicillin, norfloxacin, ciprofloxacin, gatifloxacin, ofloxacin, amoxyclav, ceftazidime, cefepime, cefixime, piperacillin and imipenem. The ESBL-producing and fluoroquinolone-resistant K. pneumoniae strains were more prevalent than the K. oxytoca strains in the HA/CA samples. The minimum inhibitory concentration values of the third-generation cephalosporins: cefotaxime and ceftazidime and the fluoroquinolones: ciprofloxacin and levofloxacin against both species of Klebsiella confirmed the resistance in the current/coveted treatment options. CONCLUSIONS: Patients with other bacterial infections had a relatively higher probability of infection with ESBL-producing and fluoroquinolone-resistant Klebsiella strains. The data presented here highlight the alarming state of Klebsiella infection dynamics in the hospital and adjoining communities.

Antagonism at combined effects of chemical fertilizers and carbamate insecticides on the rice-field N2-fixing cyanobacterium Cylindrospermum sp. in vitro.

Effects of chemical fertilizers (urea, super phosphate and potash) on toxicities of two carbamate insecticides, carbaryl and carbofuran, individually to the N2-fixing cyanobacterium, Cylindrospermum sp. were studied in vitro at partially lethal levels (below highest permissive concentrations) of each insecticide. The average number of vegetative cells between two polar heterocysts was 16.3 in control cultures, while the mean value of filament length increased in the presence of chemical fertilizers, individually. Urea at the 10 ppm level was growth stimulatory and at the 50 ppm level it was growth inhibitory in control cultures, while at 100 ppm it was antagonistic, i.e. toxicity-enhancing along with carbaryl, individually to the cyanobacterium, antagonism was recorded. Urea at 50 ppm had toxicity reducing effect with carbaryl or carbofuran. At 100 and 250 ppm carbofuran levels, 50 ppm urea only had a progressive growth enhancing effect, which was marked well at 250 ppm carbofuran level, a situation of synergism. Super phosphate at the 10 ppm level only was growth promoting in control cultures, but it was antagonistic at its higher levels (50 and 100 ppm) along with both insecticides, individually. Potash (100, 200, 300 and 400 ppm) reduced toxicity due to carbaryl 20 and carbofuran 250 ppm levels, but potash was antagonistic at the other insecticide levels. The data clearly showed that the chemical fertilizers used were antagonistic with both the insecticides during toxicity to Cylindrospermum sp.

Statistical Evaluation of Two Microbiological Diagnostic Methods of Pulmonary Tuberculosis After Implementation of a Directly Observed Treatment Short-course Program.

OBJECTIVES: To evaluate the diagnostic accuracy of smear and culture tests of clinical samples of pulmonary tuberculosis after the introduction of the directly observed treatment short-course (DOTS) program. METHODS: Using sputum samples from 572 individuals as a self-selected population, both Ziehl-Neelsen staining and culturing on Lowenstein-Jensen medium were carried out as diagnostic procedures. Using Bayes' rule, the obtained data set was analyzed. RESULTS: Of the 572 samples, 33 (0.05769) were true positive (results of both tests positive) cases; 22 samples (0.03846) were false positive (smear test positive and culture test negative) cases; 62 samples (0.10839) were false negative (smear test negative and culture test positive) cases; and 455 samples (0.79545) were true negative (results of both tests negative) cases. Values of test statistics, sensitivity, and specificity were used to compute several inherent other Bayesian test statistics. The a priori probability or prevalence value of tuberculosis in the targeted population was 0.166. The a posteriori probability value computed arithmetically was 0.6614 and that obtained by the graphical method was 0.62. CONCLUSIONS: The smear test was found to be dependable for 95.4% with stable TB infections, and it was not dependable for 34.7% without stable TB infections. The culture test could be regarded as the gold standard for 96.15% as seen with the data set, which was obtained after the implementation of the DOTS program.

A report on infection dynamics of inducible clindamycin resistance of Staphylococcus aureus isolated from a teaching hospital in India.

OBJECTIVE: To investigate the infection of hospital- and community-acquired "erythromycin-induced clindamycin resistant" strains or D-test positives of clinical isolates of Staphylococcus aureus (S. aureus) (with and without methicillin resistance) in a hospital. METHODS: Strains of S. aureus isolated from clinical specimens were subjected to D-test and antibiotic profiling. RESULTS: Of the total 278 isolates, 140 (50.35%) were D-test positives and the rest were D-test negatives. Further, of 140 (100%) positives, 87 (62.14%) and 53 (37.85%) strains were from males and females, respectively. Of 140 (100%) positives, 117 (83.57%) were methicillin resistant S. aureus and 23 (16.42%) were methicillin sensitive S. aureus; of 140 strains, 103 (73.57%) strains from persons with and 37 (26.42%) were without related infections; of 140 strains, 91 (65%) and 49 (35%) were from hospital- and community-acquired samples, respectively. In 140 strains, 118 (84.28%) with comorbidities and 22 (15.71%) without comorbidities cases were recorded; similarly, persons with prior antibiotic uses contributed 108 (77.14%) and without 32 (22.85%) positive strains. These binary data of surveillance were analyzed by a univariate analysis. It was evident that the prior antibiotic uses and comorbidities due to other ailments were the determinative factors in D-test positivity, corroborated by low P values, P=0.001 1 and 0.002 4, respectively. All isolates (278) were resistant to 17 antibiotics of nine groups, in varying degrees; the minimum of 28% resistance for vancomycin and the maximum of 97% resistance for gentamicin were recorded. Further, of 278 strains, only 42 (15.1%) strains were resistant constitutively to both antibiotics, erythromycin resistant and clindamycin resistant, while 45 (16.2%) strains were constitutively sensitive to both antibiotics (erythromycin sensitive and clindamycin sensitive). Further, of the rest 191 (68.7%) strains were with erythromycin resistant and clindamycin resistant, of which only 140 (50.35%) strains were D-test positives, while the rest 51 (18.34%) strains were D-test negatives. CONCLUSIONS: In view of high prevalence of D-test positive S. aureus strains, and equally high prevalence of multidrug resistant strains both in community and hospital sectors, undertaking of D-test may be routinely conducted for suppurative infections.

Which value should be used as the lethal concentration 50 (LC(50)) with bacteria?

Computations of lethal concentration 50 (LC(50)) of a data-set of a toxicity study on an herbicide against a cyanobacterium were performed by general linear regression, Spearman-Karber and probit transformation methods, for evaluation of the methods used. It is shown that the linear regression method yields some faulty LC(50) value, while both of Spearman-Karber and probit methods yield similar and statistically respectable LC(50) values. In the Spearman-Karber method, a prerequisite of some uniform dose-interval of test-chemical and tiring calculations were involved. But, the probit method is less tiring and additionally computed LC(25) and LC(75) values help assess the solicited accuracy of the LC(50) value and other test-statistics, including minimum inhibitory concentration (MIC), highest-permissive concentration (HPC), and a few more with respect to lethal concentration 100 (LC(100)) without prerequisite of any uniform dose-interval of test-chemical. Further, the redundancy of computations of standard error (SE) and 95% confidence limits (CL) of the LC(50) value is suggested, as CL values are so wide to spoil LC(50) accuracy that is solicited in toxicology.