Divergent evolution of Corynebacterium diphtheriae in India: An update from National Diphtheria Surveillance network

Diphtheria is caused by a toxigenic bacterium Corynebacterium diphtheria which is being an emerging pathogen in India. Since diphtheria morbidity and mortality continues to be high in the country, the present study aimed to study the molecular epidemiology of C. diphtheriae strains from India. A total of 441 diphtheria suspected specimens collected as part of the surveillance programme between 2015 and 2020 were studied. All the isolates were confirmed as C. diphtheriae with standard biochemical tests, ELEK's test, and real-time PCR. Antimicrobial susceptibility testing for the subset of isolates showed intermediate susceptibility to penicillin and complete susceptible to erythromycin and cefotaxime. Isolates were characterized using multi locus sequence typing method. MLST analysis for the 216 C. diphtheriae isolates revealed major diversity among the sequence types. A total of 34 STs were assigned with majority of the isolates belonged to ST466 (30%). The second most common ST identified was ST405 that was present in 14% of the isolates. The international clone ST50 was also seen. The identified STs were grouped into 8 different clonal complexes (CC). The majority belongs to CC5 followed by CC466, CC574 and CC209, however a single non-toxigenic strain belongs to CC42. This epidemiological analysis revealed the emergence of novel STs and the clones with better dissemination properties. This study has also provided information on the circulating strains of C. diphtheriae among the different regions of India. The molecular data generated through surveillance system can be utilized for further actions in concern.

Genetic Diversity of Clinical Bordetella Pertussis ST2 Strains in comparison with Vaccine Reference Strains of India

Objectives: Pertussis is a highly contagious disease of the respiratory tract caused by Bordetella pertussis, a bacterium that lives in the mouth, nose, and throat. Current study reports the highly accurate complete genomes of two clinical B. pertussis strains from India for the first time.

Methods: Complete genome sequencing was performed for two B. pertussis strains using Ion Torrent PGM and Oxford nanopore sequencing method. Data was assembled de novo and the sequence annotation was performed through PATRIC and NCBI server. Downstream analyses of the isolates were performed using CGE server databases for antimicrobial resistance genes, plasmids, and sequence types. The phylogenetic analysis was performed using Roary.

Results: The analysis revealed insertional elements flanked by IS481, which has been previously regarded as the important component for bacterial evolution. The two B. pertussis clinical strains exhibited diversity through genome degradation when compared to whole-cell vaccine reference strains of India. These isolates harboured multiple genetic virulence traits and toxin subunits, which belonged to sequence type ST2.

Conclusion: The genome information of Indian clinical B. pertussis strains will serve as a baseline data to decipher more information on the genome evolution, virulence factors and their role in pathogenesis for effective vaccine strategies.

Cholera outbreak investigation, Bhadola, Delhi, India, April-May 2018

BACKGROUND

In the Gangetic plains of India, including Delhi, cholera is endemic. On 10 May 2018, staff at the north Delhi district surveillance unit identified a laboratory-confirmed cholera outbreak when five people tested positive for Vibrio cholerae O1 Ogawa serotype in Bhadola. We investigated to identify risk factors and recommend prevention measures.

METHODS

We defined a case as ≥3 loose stools within 24 h in a Bhadola resident during 1 April-29 May 2018. We searched for cases house-to-house. In a 1 : 1 unmatched case control study, a control was defined as an absence of loose stools in a Bhadola resident during 1 April-29 May 2018. We selected cases and controls randomly. We tested stool samples for Vibrio cholerae by culture. We tested drinking water for fecal contamination. Using multivariable logistic regression we calculated adjusted ORs (aORs) with 95% CIs.

RESULTS

We identified 129 cases; the median age was 14.5 y, 52% were females, 27% were hospitalized and there were no deaths. Symptoms were abdominal pain (54%), vomiting (44%) and fever (29%). Among 90 cases and controls, the odds of illness were higher for drinking untreated municipal water (aOR=2.3; 95% CI 1.0 to 6.2) and not knowing about diarrhea transmission (aOR=4.9; 95% CI 1.0 to 21.1). Of 12 stool samples, 6 (50%) tested positive for Vibrio cholerae O1 Ogawa serotype. Of 15 water samples, 8 (53%) showed growth of fecal coliforms.

CONCLUSIONS

This laboratory-confirmed cholera outbreak associated with drinking untreated municipal water and lack of knowledge of diarrhea transmission triggered public health action in Bhadola, Delhi.

Spatiotemporal persistence of multiple, diverse clades and toxins of Corynebacterium diphtheriae

Diphtheria is a respiratory disease caused by the bacterium Corynebacterium diphtheriae. Although the development of a toxin-based vaccine in the 1930s has allowed a high level of control over the disease, cases have increased in recent years. Here, we describe the genomic variation of 502 C. diphtheriae isolates across 16 countries and territories over 122 years. We generate a core gene phylogeny and determine the presence of antimicrobial resistance genes and variation within the tox gene of 291 tox+ isolates. Numerous, highly diverse clusters of C. diphtheriae are observed across the phylogeny, each containing isolates from multiple countries, regions and time of isolation. The number of antimicrobial resistance genes, as well as the breadth of antibiotic resistance, is substantially greater in the last decade than ever before. We identified and analysed 18 tox gene variants, with mutations estimated to be of medium to high structural impact.

Evaluation of spinopelvic parameters in lumbar prolapsed intervertebral disc

Background:

Sacro-pelvic morphology and orientation are usually described in terms of pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Orientation and morphology of pelvis can affect degenerative changes in the lumbar spine. Thus, here we investigated the relationships between various sagittal spinopelvic parameters and the degree of disc degeneration in young adults.

Material and Methods:

A hospital-based cross-sectional study with a total of 60 cases was done. Patients presenting with back or leg pain having prolapsed disc on magnetic resonance imaging (MRI) were included in the study. A standing X-ray of LS spine from dorso-lumbar junction to mid-thigh was taken. Various spinopelvic parameters were assessed from the scannogram using the software.

Results:

The mean age was 39.27 years. L5S1 was the most common level. Mean SS, PT, PI, and LL were 37.78°, 13.52°, 51.33°, and 41.01°. Disc pathologies at L1L2, L2L3, and L4L5 level showed a positive correlation with PT, PI, and LL. Disc pathology at the L5S1 level shows a positive correlation with PT and LL. A statistically significant correlation between SS and degenerative spondylolisthesis at L4L5 was found from data with P = 0.023.

Discussion:

An increase in SS statistically significantly increases the chance of development of degenerative spondylolisthesis at L4L5. An increase in PT, PI, and LL will cause an increase in disc pathology at L1L2. An increase in SS, PT, PI, and LL will cause an increase in disc pathology at L2L3. An increase in SS, PT, PI, and LL will cause an increase in disc pathology at L4L5. An increase in PT and LL will cause an increase in disc pathology at L5S1.

Conclusion:

Standing lateral view radiograph from dorso-lumbar junction to the mid-thigh is as good as standing whole spine radiograph for measurement of spinopelvic parameters. Degenerative spondylolisthesis at L4L5 has a statistically significant correlation with an increase in SS.

Diphtheria

Diphtheria is a potentially fatal infection mostly caused by toxigenic Corynebacterium diphtheriae strains and occasionally by toxigenic C. ulcerans and C. pseudotuberculosis strains. Diphtheria is generally an acute respiratory infection, characterized by the formation of a pseudomembrane in the throat, but cutaneous infections are possible. Systemic effects, such as myocarditis and neuropathy, which are associated with increased fatality risk, are due to diphtheria toxin, an exotoxin produced by the pathogen that inhibits protein synthesis and causes cell death. Clinical diagnosis is confirmed by the isolation and identification of the causative Corynebacterium spp., usually by bacterial culture followed by enzymatic and toxin detection tests. Diphtheria can be treated with the timely administration of diphtheria antitoxin and antimicrobial therapy. Although effective vaccines are available, this disease has the potential to re-emerge in countries where the recommended vaccination programmes are not sustained, and increasing proportions of adults are becoming susceptible to diphtheria. Thousands of diphtheria cases are still reported annually from several countries in Asia and Africa, along with many outbreaks. Changes in the epidemiology of diphtheria have been reported worldwide. The prevalence of toxigenic Corynebacterium spp. highlights the need for proper clinical and epidemiological investigations to quickly identify and treat affected individuals, along with public health measures to prevent and contain the spread of this disease.

Prevalence of Multidrug Resistant Salmonellae with Increasing Frequency of Salmonella enterica Serovars Kentucky and Virchow among Hospitalized Diarrheal Cases in and around Delhi, India

Non-typhoidal salmonellae (NTS) are a major cause of acute diarrhea with characteristic multidrug resistance (MDR). In a hospital-based study, 81 NTS were isolated and tested for serotypes and antimicrobial resistance (AMR). Salmonella enterica isolates were classified into 7 different typable serovars, however, 19 (23%) isolates remained untypable. The most common serovars were S. Kentucky (48%), and S. Virchow (22%). Most of the NTS isolates displayed resistance to nalidixic acid (NA) (73%), ciprofloxacin (CIP) (48%), ampicillin (AM) and norfloxacin (NOR) (36% each), and gentamicin (CN) (31%). The AMR profiles for CN and NA; and AM, CIP, NA and NOR, were found to be high in S. Virchow (83%) and S. Kentucky (43%), respectively. Analysis of the pulsed-field gel electrophoresis patterns of S. Kentucky revealed 3 clusters. S. Kentucky has clones closely related to become prominent in recent years in Delhi. The AMR appears to be consistent with the change in MDR patterns during 2014-2017. The observed prevalence of S. Kentucky and S. Virchow in large numbers of diarrheal cases is novel. The NTS are mostly resistant to fluoroquinolones, which is the current drug of choice for treating diarrheal cases. MDR is very common among clonally related S. Kentucky.

Insights to the diphtheria toxin encoding prophages amongst clinical isolates of Corynebacterium diphtheriae from India

Diphtheria is a dreadful disease caused by Corynebacterium diphtheriae. Lysogenised bacteriophages carrying toxin gene in C. diphtheriae can make the strain toxigenic. However, such phage disseminates the toxin genes to other strains when it undergoes lytic phase. As little is known about the phage diversity in C. diphtheriae in India, the present study was undertaken to investigate the prophages integrated into the genome of 29 clinical isolates of C. diphtheriae using whole-genome shotgun sequencing. Amongst these isolates, 27 were toxigenic, while 2 were non-toxigenic strains. Of the 27 toxigenic strains, all harbored known phages carrying toxin gene and two other phages with unknown function. However, the two non-toxin strains did not harbour any of the phages in the genome. It is imperative to devise prevention strategies that hinder the dissemination of toxin by prophages, as it may increase the complications of diphtheria post-immunisation.

Publisher Correction: Genomic insights into the 2016-2017 cholera epidemic in Yemen

In the HTML version of this Letter, the affiliations for authors Andrew S. Azman, Dhirendra Kumar and Thandavarayan Ramamurthy were inverted (the PDF and print versions of the Letter were correct); the affiliations have been corrected online.

Genomic insights into the 2016-2017 cholera epidemic in Yemen

Yemen is currently experiencing the largest cholera epidemic in recent history. The first cases were declared in September 2016, and over 1.1 million cases and 2,300 deaths have since been reported1. We investigated the phylogenetic relationships, pathogenesis, and antimicrobial resistance determinants by sequencing the genomes of Vibrio cholerae isolates from the Yemen epidemic and recent isolates from neighbouring regions. These 116 genomic sequences were placed within the phylogenetic context of a global collection of 1087 seventh pandemic V. cholerae serogroup O1 and O139 biotype El Tor isolates [2–4]. We show that the Yemeni isolates collected during the two epidemiological waves of the epidemic [1], —the first between September 28^th 2016 and April 23^rd 2017 (25,839 suspected cases) and the second beginning on April 24^th, 2017 (more than one million suspected cases), — are seventh pandemic V. cholerae O1 El Tor (7PET) serotype Ogawa isolates from a single sublineage. Using genomic approaches, we link the Yemen epidemic to global radiations of pandemic V. cholerae and show that this sublineage originated from South Asia and that it caused outbreaks in East Africa before appearing in Yemen. We also show that the Yemeni isolates are susceptible to several antibiotics commonly used to treat cholera, and to polymyxins, resistance to which is used as a marker of the El Tor biotype.

Zinc oxide nanoparticles (ZnONPs) alleviate heavy metal-induced toxicity in Leucaena leucocephala seedlings: A physiochemical analysis

The present study describes the role of zinc oxide nanoparticles (ZnONPs) in reversing oxidative stress symptoms induced by heavy metal (Cd and Pb) exposure in Leucaena leucocephala (Lam.) de Wit. Seedling growth was significantly enhanced with the augmentation of ZnONPs following Cd and Pb exposure. Heavy metal accumulations were recorded as 1253.1 mg Cd per kg DW and 1026.8 mg Pb per kg DW for the respective treatments. Results demonstrated that ZnONPs augmentation caused an increase in photosynthetic pigment and total soluble protein contents while a significant decrease in malondialdehyde (MDA-lipid peroxidation) content in leaves. Antioxidative enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were, in turn, elevated in heavy metal-exposed leaves amended with ZnONPs. The ameliorating effect of ZnO nanoparticles on oxidative stress induced toxicity was also confirmed by the reduced MDA content and the elevated level of antioxidative enzyme activities in leaf tissues of L. leucocephala seedlings. Further, addition of ZnONPs in combination with Cd and Pb metals induced distinct genomic alterations such as presence of new DNA bands and/or absence of normal bands in the RAPD pattern of the exposed plants. This study uniquely suggests a potential role of zinc oxide nanoparticles in the remediation of heavy metal contaminated media.

Advance care planning: identifying system-specific barriers and facilitators

BACKGROUND

Advance care planning (acp) is an important process in health care today. How to prospectively identify potential local barriers and facilitators to uptake of acp across a complex, multi-sector, publicly funded health care system and how to develop specific mitigating strategies have not been well characterized.

METHODS

We surveyed a convenience sample of clinical and administrative health care opinion leaders across the province of Alberta to characterize system-specific barriers and facilitators to uptake of acp. The survey was based on published literature about the barriers to and facilitators of acp and on the Michie Theoretical Domains Framework.

RESULTS

Of 88 surveys, 51 (58%) were returned. The survey identified system-specific barriers that could challenge uptake of acp. The factors were categorized into four main domains. Three examples of individual system-specific barriers were "insufficient public engagement and misunderstanding," "conflict among different provincial health service initiatives," and "lack of infrastructure." Local system-specific barriers and facilitators were subsequently explored through a semi-structured informal discussion group involving key informants. The group identified approaches to mitigate specific barriers.

CONCLUSIONS

Uptake of acp is a priority for many health care systems, but bringing about change in multi-sector health care systems is complex. Identifying system-specific barriers and facilitators to the uptake of innovation are important elements of successful knowledge translation. We developed and successfully used a simple and inexpensive process to identify local system-specific barriers and enablers to uptake of acp, and to identify specific mitigating strategies.

Assessment of the effects of a stannous fluoride dentifrice on gingivitis in a two-month positive-controlled clinical study

OBJECTIVE

The purpose of this study was to evaluate the anti-gingivitis effectiveness of a 0.454% stannous fluoride test dentifrice relative to a marketed positive-control triclosan-containing dentifrice in adults with gingivitis.

METHODS

This was a two-month, randomized and controlled, double-blind, parallel group, single-center investigation involving 150 adults with existing mild to moderate gingivitis. Pre-treatment gingivitis levels were assessed at baseline using the Lobene Modified Gingival Index (MGI) and the Gingival Bleeding Index (GBI). Qualified subjects were randomly assigned to either a 0.454% stannous fluoride test dentifrice or a marketed, positive-control 0.30% triclosan/copolymer dentifrice. Subjects then brushed for two months unsupervised in the home setting with their assigned dentifrice per manufacturer's instructions. At Month 2, subjects were re-evaluated for gingivitis via MGI and GBI examinations.

RESULTS

All 150 enrolled subjects completed the trial and were evaluable. Both the stannous fluoride test and triclosan/copolymer control dentifrices provided statistically significant reductions in average MGI, GBI, and number of bleeding sites relative to pre-treatment (p < 0.0001) at Month 2. The adjusted mean improvement from baseline at Month 2 for the stannous fluoride test dentifrice group was 65% greater for number of bleeding sites, 62% greater for GBI, and 45% greater for MGI compared to the triclosan/copolymer positive-control group, with groups differing significantly (p < 0.0001) via each of the three gingivitis measures. Both dentifrices were well-tolerated.

CONCLUSION

An advanced stannous fluoride test dentifrice provided superior reductions in gingival inflammation and gingival bleeding compared to a commercially available triclosan/copolymer positive-control dentifrice after two months of tooth brushing.

Long-segment intramedullary spinal dermoid

A 30-year-old man presented with a fairly large intramedullary mass lesion involving virtually the entire spinal cord. It was hyperintense on both T1W and T2W sequences, with signal suppression on fat-saturation images. Subsequent noncontrast CT scan of the spine confirmed the presence of fat and calcification within the lesion, thus leading to the diagnosis of an intramedullary dermoid.

The plaque removal efficacy of a novel power brush head

OBJECTIVE

To assess the plaque removal efficacy of an oscillating/rotating power toothbrush with novel brush head (Oral-B Precision Clean) in comparison to an American Dental Association (ADA) reference manual toothbrush.

METHODS

This was a replicate-use, single-brushing, two-treatment, examiner-blind, randomized, four-period (visit) study with a crossover design. At each visit, subjects disclosed their plaque with disclosing solution for one minute, and an examiner performed a baseline (pre-brushing) plaque examination (Rustogi, et al. Modification of the Navy Plaque Index). Subjects were then instructed to brush for two minutes (according to manufacturer's instructions) with their assigned power toothbrush or as they normally do with the ADA manual brush under supervision, after which they again disclosed their plaque and were given a post-brushing plaque examination.

RESULTS

Both the power brush and manual brush showed statistically significant plaque reductions from baseline for the whole mouth, along the gingival margin, and on approximal surfaces. The power brush showed statistically significant advantages (p < 0.001) over the manual brush in plaque reduction for whole mouth (28.8%), gingival margin (44.3%), and approximal surfaces (20.7%).

CONCLUSION

The oscillating/rotating power toothbrush with a novel brush head showed statistically significantly superior plaque reduction (whole mouth, gingival margin, and approximal surfaces) compared to a manual toothbrush.

A clinical evaluation of the plaque removal efficacy of five manual toothbrushes

OBJECTIVE

To assess and compare the plaque removal efficacy of five different Oral-B manual toothbrushes: CrossAction Pro-Health (CAPH), CrossAction (CA), Exceed (EX), Advantage 123 (ADV 123), and Indicator (IND).

METHODS

This was a single-use, five-treatment, examiner-blind, randomized, five-period (visit) crossover study, with 10 different treatment sequences (groups) that determined the order in which the five toothbrushes were assigned at study visits. Three toothbrushes had an advanced CrissCross bristle design (CAPH, CA, EX), while two had more standard designs with straight bristles (ADV 123 and IND). At the first visit, subjects disclosed their plaque with disclosing solution, and an examiner performed a baseline plaque examination using the Rustogi, et al. Modification of the Navy Plaque Index (RMNPI). Subjects brushed for one minute with their assigned toothbrush under supervision, after which they again disclosed their plaque and were given a second plaque examination. The same procedure was followed for each of the visits in turn.

RESULTS

All five manual toothbrushes showed a statistically significant (p < 0.0001) reduction in plaque from baseline for the whole mouth (84% to 93%), gingival margin (74% to 88%), and approximal surfaces (95% to 99%). For pair-wise treatment comparisons for all three plaque measures, CAPH, CA, and EX demonstrated statistically significantly better plaque removal than ADV 123 and IND (all p < 0.018). No other treatment comparisons were statistically significant.

CONCLUSION

All five manual toothbrushes showed highly effective plaque reduction for whole mouth, gingival margin, and approximal surfaces. Comparisons between brushes showed consistent advantages for CAPH, CA, and EX compared to ADV 123 and IND for all three plaque measures, indicating that advances in toothbrush design can further enhance plaque removal.

Bacteriological & epidemiological characteristics of diphtheria cases in & around Delhi -a retrospective study

BACKGROUND & OBJECTIVE

Diphtheria infections caused by the different toxigenic biotypes of Corynebacterium diphtheriae are endemic in Delhi. Information on biochemical identification, toxigenicity and antimicrobial susceptibility to this bacterium is scanty. This retrospective study was carried out to identify isolated Corynebacteria biochemically, determine their toxigenicity, drug sensitivity and some epidemiological characteristics of diphtheria cases from Delhi and adjoining States for the period 1998-2004.

METHODS

A total of 1118 throat and 585 nasal swabs were used to detect human pathogenic corynebacteria. WHO recommended methods were used for the detection, screening, toxigenicity and antibiogram pattern of the isolates.

RESULTS

Among 493 (44.1%) cases detected positive for corynebacteria 71.8 per cent were pharyngeal, 20.9 per cent nasopharyngeal and rest 7.3 per cent nasal diphtheria cases. Biochemical identification revealed two species i.e., C. diphtheriae and C. pseudodiphtheriticum. In C. diphtheriae three biotypes were detected viz., intermedius (95.5%), gravis (3.4%) and mitis (1.1%). Toxin was expressed by 96 per cent isolates of C. diphtheriae. Cases were recorded from Delhi and four adjoining States. Sex ratio among male to female was 1.6:1. Prime victims were less than 9 yr old children (93.3%). Unvaccinated children (70.2%) were the main sufferers. Fatality rate was highest in Delhi cases (16.8%) followed by UP (14.6%) and Haryana (5.9%).

INTERPRETATION & CONCLUSION

Standard methods revealed the replacement of C. diphtheriae var mitis with var intermedius and occurrence of diphtheria infections due to other human pathogenic corynebacteria. It is imperative to have good bacteriological facilities to have better surveillance with regular monitoring in the endemic areas to keep the disease under control.

Changing profile of Vibrio cholerae O1, O139 in Delhi & its periphery (2003-2005)

BACKGROUND & OBJECTIVE

Cholera caused by either Vibrio cholerae O1 or O139 is endemic in Delhi and its peripheral areas. The present study was carried out to understand the changing epidemiology of V. cholerae in terms of prevalence of serotypes, antibiogram pattern and phage types.

METHODS

A total of 9858 stool samples from the admitted diarrhoea patients were used for the isolation of V. cholerae O1 and O139. Subsets of isolates were tested against thirteen antimicrobials and phage typed.

RESULTS

Among 4251 (43.1%) confirmed cases, 41.6 per cent were V. cholerae O1 and rest (1.5 %) V. cholerae O139. Detection of V. cholerae O1 serotype Inaba was 87.7 per cent during 2005 and rest were serotype Ogawa. Majority of cases (93.1%) were from Delhi. Male:Female ratio remained 1.5:1.0. Children below 5 yr age group constituted 32.7 per cent cases. Shift in the age groups and seasonal incidence were recorded. All 226 strains of V. cholerae O1 and O139 were resistant to nalidixic acid; 96 per cent V. cholerae O1 isolates were multidrug resistant (FX NA SXT). Phage type 27 (98.7%) was the most prevalent and the new phage types were 4, 16 and 25 in this area.

INTERPRETATION & CONCLUSION

Enhanced surveillance helped in bringing down cases from 47.7 per cent in 2003 to 36.8 per cent in 2005. Additionally, the changing epidemiology of V. cholerae O1 and O139 infections and drug resistance need regular monitoring.

Spread of cholera with newer clones of Vibrio cholerae O1 El Tor, serotype inaba, in India

During 2004 and 2005, cholera was recorded in 15 states of India, with 7 outbreaks. The newly emerged Vibrio cholerae O1 Inaba had a different antibiogram and ribotype, different pulsotypes, and different mutations in the wbeT gene. Due to the absence of serogroup O139, the Inaba serotype may have acquired the potential to affect the population at large.

A comparison of the plaque removal efficacy of two power toothbrushes: Oral-b Professional Care Series versus Sonicare Elite

AIM

To compare the safety and plaque removal efficacy of an oscillating/ pulsating toothbrush (Professional Care Series, Oral-B Laboratories; PCS) and a high frequency toothbrush (Sonicare Elite, Philips Oral Healthcare; SE).

METHODS

The study had a randomised, examiner-blind, crossover design. Sixty-one subjects aged 19-64 years were enrolled. After 23-25 hours of no oral hygiene, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores > or = 0.60 measured by the Rustogi modified Navy Plaque Index were randomly assigned to treatment sequence. Subjects brushed with their assigned toothbrush for 2 minutes using a commercially available dentifrice. Oral tissues were then re-examined and post-brushing plaque scores recorded. After a brief washout period, the above procedures were repeated with the alternate toothbrush. One examiner blinded to the treatment sequence performed all clinical measurements.

RESULTS

All 61 subjects completed the study. Both toothbrushes significantly reduced plaque levels after a single brushing (t-test, p < 0.0001). However, the PCS was significantly more effective than the SE in whole mouth plaque removal and in reducing plaque from marginal, buccal, lingual and approximal surfaces (ANOVA, p < 0.0001). Whole mouth plaque was reduced by 88% versus 61% and approximal plaque by 97% versus 73% for the PCS and SE toothbrushes, respectively. There was no evidence of hard or soft tissue trauma after a single-use of either toothbrush.

CONCLUSION

Based on the findings of this single-use clinical evaluation, the action of the oscillating/ pulsating power toothbrush is more effective at plaque removal than a high frequency power toothbrush.

Plaque removal efficacy of two electric toothbrushes with different brush head designs

OBJECTIVES.: To compare the safety and plaque removal efficacy of two electric toothbrushes, one a rechargeable oscillating/pulsating toothbrush with a small round brush head (Oral-B ProfessionalCaretrade mark 7000; PC 7000), the other a battery-operated toothbrush with a dual moving brush head (Crest(R) SpinBrushtrade mark Pro; SBP). METHODS.: The study had a randomised, examiner-blind, two-arm crossover design. All subjects received an oral prophylaxis and used both toothbrushes on alternating days for a two-week practice period. After abstaining from all oral hygiene procedures for 23-25 hours, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores >/=0.60 measured by the Rustogi et al. Modified Navy Plaque Index were randomly assigned to treatment sequence. Subjects brushed with their assigned toothbrush for 2 minutes using a commercially available dentifrice. Oral tissues were then re-examined and post-brushing plaque scores recorded. After a brief washout period, the above procedures were repeated with the alternate toothbrush. One examiner, blinded to the treatment sequence, performed all clinical measurements. RESULTS.: A total of 70 subjects (24 males and 46 females) were enrolled and completed the study. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing. The PC 7000 was significantly more effective in plaque removal than the SBP at all tooth areas, reducing whole mouth plaque by 61% versus 58% and plaque from approximal surfaces by 69% versus 65%, respectively. CONCLUSIONS.: The action of the oscillating/pulsating toothbrush with a small round brush head, Oral-B ProfessionalCare 7000, is more effective in plaque removal than the battery-operated Crest SpinBrush Pro toothbrush with a larger dual moving brush head.

Single-use plaque removal efficacy of three power toothbrushes

OBJECTIVES.: To compare the safety and plaque removal efficacy of two oscillating/rotating/pulsating toothbrushes (Oral-B ProfessionalCaretrade mark 7000 [PC 7000] and Oral-B 3D Excel [3DE]) and a high-frequency toothbrush (Sonicare(R) Advance, Philips Oral Healthcare; SA) in a single-use, examiner-blind, three period crossover study. METHODS.: After refraining from all oral hygiene procedures for 23-25 hours, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores 0.6 based on the Rustogi et al. Modified Navy Plaque Index were randomly assigned to treatment sequence. After brushing with the assigned toothbrush and a commercially available dentifrice for 2 minutes, oral tissues were then re-examined and post-brushing plaque scores recorded. Following a brief washout period between two additional visits, the above procedures were repeated with the two alternate toothbrushes. One examiner, blinded to the treatment sequence, performed all clinical measurements. RESULTS.: A total of 79 subjects (28 males and 51 females) were enrolled and completed the study. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing. The PC 7000 and 3DE were equally more effective in plaque removal than the SA, at all tooth areas, reducing plaque by 59.0%, 59.7% and 51.8%, respectively on whole mouth surfaces, and by 67.5%, 67.8% and 59.4%, respectively on approximal surfaces. CONCLUSIONS.: The action of the oscillating/rotating/pulsating toothbrushes (Oral-B ProfessionalCare 7000 and Oral-B 3D Excel) was more effective in plaque removal than the high-frequency toothbrush (Sonicare Advance).

Efficacy of a novel brush head in the comparison of two power toothbrushes on removal of plaque and naturally occurring extrinsic stain

OBJECTIVES

To compare the safety and efficacy of an oscillating/pulsating power toothbrush (Oral-B ProfessionalCareTM 7000; PC 7000) fitted with either the standard FlexiSoft (PC 7000/EB17) brush head or the novel Pro Polisher (PC 7000/ EB-Prophy) and a high-frequency toothbrush (Philips Sonicare Elite; SE), in their relative ability to remove plaque and naturally occurring extrinsic dental stain over a six-week period.

METHODS

This randomised, examiner-blind, parallel group study involved 90 healthy subjects from a general population. All subjects received a baseline plaque (Turesky et al. modified Quigley-Hein Plaque Index), stain (Lobene Stain Index) and tooth shade (VITAPAN Shade Guide) [Vita] assessment and an oral tissue examination. After training in the use of their randomly assigned device, subjects were instructed to brush twice daily for 2 min and returned after 3, 4 and 6 weeks of product use for a repeat of each clinical assessment.

RESULTS

Reductions from baseline in mean plaque and extrinsic dental stain scores were significant at Weeks 3, 4 and 6 in all three treatment groups. By Week 6, mean reductions from baseline in whole mouth plaque scores were 32%, 27% and 14% in the PC 7000/EB-Prophy, PC 7000/EB17 and SE groups, respectivety. For the body of the tooth, mean reductions from baseline at Week 6 in total stain were 89%, 89% and 80%, respectively. Between treatment group comparisons consistently revealed that the PC 7000 toothbrush plus the EB-Prophy or EB17 brush head removed significantly more plaque and extrinsic stain (total stain, stain area and stain intensity) than the SE toothbrush at 3, 4 and 6 weeks. The EB-Prophy group had a greater proportion of subjects showing a 2-3+ change in Vita shade scores at each time point compared to the other two brushes; at Week 6 the proportions were 67% in the PC 7000/EB-Prophy group, 30% in the PC 7000/EB17 group, and 7% in the SE group. The PC 7000/EB17, PC 7000/EB-Prophy and the SE were found to be safe as used in the study.

CONCLUSIONS

The oscillating/rotating/pulsating PC 7000 (fitted with either the standard EB17 or novel EB-Prophy brush head) is more effective at removal of plaque and naturally occurring extrinsic tooth stain, and the PC 7000 plus EB-Prophy in the improvement of tooth shade, than the high-frequency SE toothbrush.

Single-use plaque removal efficacy of three power toothbrushes

OBJECTIVES

To compare the safety and plaque removal efficacy of two oscillating/rotating/pulsating toothbrushes (Oral-B ProfessionalCare 7000 [PC 7000] and Oral-B 3D Excel [3DE]) and a high-frequency toothbrush (Sonicare Advance, Philips Oral Healthcare; SA) in a single-use, examiner-blind, three period crossover study.

METHODS

After refraining from all oral hygiene procedures for 23-25 hours, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores > or = 0.6 based on the Rustogi et al. Modified Navy Plaque Index were randomly assigned to treatment sequence. After brushing with the assigned toothbrush and a commercially available dentifrice for 2 minutes, oral tissues were then re-examined and post-brushing plaque scores recorded. Following a brief washout period between two additional visits, the above procedures were repeated with the two alternate toothbrushes. One examiner, blinded to the treatment sequence, performed all clinical measurements.

RESULTS

A total of 79 subjects (28 males and 51 females) were enrolled and completed the study. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing. The PC 7000 and 3DE were equally more effective in plaque removal than the SA, at all tooth areas, reducing plaque by 59.0%, 59.7% and 51.8%, respectively on whole mouth surfaces, and by 67.5%, 67.8% and 59.4%, respectively on approximal surfaces.

CONCLUSIONS

The action of the oscillating/rotating/pulsating toothbrushes (Oral-B ProfessionalCare 7000 and Oral-B 3D Excel) was more effective in plaque removal than the high-frequency toothbrush (Sonicare Advance).

Efficacy of a novel brush head in the comparison of two power toothbrushes on removal of plaque and naturally occurring extrinsic stain

OBJECTIVES.: To compare the safety and efficacy of an oscillating/pulsating power toothbrush (Oral-B ProfessionalCaretrade mark 7000; PC 7000) fitted with either the standard FlexiSoft (PC 7000/EB17) brush head or the novel Pro Polisher (PC 7000/EB-Prophy) and a high-frequency toothbrush (Philips Sonicare(R) Elite(R); SE), in their relative ability to remove plaque and naturally occurring extrinsic dental stain over a six-week period. METHODS.: This randomised, examiner-blind, parallel group study involved 90 healthy subjects from a general population. All subjects received a baseline plaque (Turesky et al. modified Quigley-Hein Plaque Index), stain (Lobene Stain Index) and tooth shade (VITAPAN(R) Shade Guide) [Vita] assessment and an oral tissue examination. After training in the use of their randomly assigned device, subjects were instructed to brush twice daily for 2 min and returned after 3, 4 and 6 weeks of product use for a repeat of each clinical assessment. RESULTS.: Reductions from baseline in mean plaque and extrinsic dental stain scores were significant at Weeks 3, 4 and 6 in all three treatment groups. By Week 6, mean reductions from baseline in whole mouth plaque scores were 32%, 27% and 14% in the PC 7000/EB-Prophy, PC 7000/EB17 and SE groups, respectively. For the body of the tooth, mean reductions from baseline at Week 6 in total stain were 89%, 89% and 80%, respectively. Between treatment group comparisons consistently revealed that the PC 7000 toothbrush plus the EB-Prophy or EB17 brush head removed significantly more plaque and extrinsic stain (total stain, stain area and stain intensity) than the SE toothbrush at 3, 4 and 6 weeks. The EB-Prophy group had a greater proportion of subjects showing a 2-3+ change in Vita shade scores at each time point compared to the other two brushes; at Week 6 the proportions were 67% in the PC 7000/EB-Prophy group, 30% in the PC 7000/EB17 group, and 7% in the SE group. The PC 7000/EB17, PC 7000/EB-Prophy and the SE were found to be safe as used in the study. CONCLUSIONS.: The oscillating/rotating/pulsating PC 7000 (fitted with either the standard EB17 or novel EB-Prophy brush head) is more effective at removal of plaque and naturally occurring extrinsic tooth stain, and the PC 7000 plus EB-Prophy in the improvement of tooth shade, than the high-frequency SE toothbrush.

Plaque removal efficacy of two electric toothbrushes with different brush head designs

OBJECTIVES

To compare the safety and plaque removal efficacy of two electric toothbrushes, one a rechargeable oscillating/pulsating toothbrush with a small round brush head (Oral-B ProfessionalCare 7000; PC 7000), the other a battery-operated toothbrush with a dual moving brush head (Crest SpinBrush Pro; SBP).

METHODS

The study had a randomised, examiner-blind, two-arm crossover design. All subjects received an oral prophylaxis and used both toothbrushes on alternating days for a two-week practice period. After abstaining from all oral hygiene procedures for 23-25 hours, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores > or = 0.60 measured by the Rustogi et al. Modified Navy Plaque Index were randomly assigned to treatment sequence. Subjects brushed with their assigned toothbrush for 2 minutes using a commercially available dentifrice. Oral tissues were then re-examined and post-brushing plaque scores recorded. After a brief washout period, the above procedures were repeated with the alternate toothbrush. One examiner, blinded to the treatment sequence, performed all clinical measurements.

RESULTS

A total of 70 subjects (24 males and 46 females) were enrolled and completed the study. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing. The PC 7000 was significantly more effective in plaque removal than the SBP at all tooth areas, reducing whole mouth plaque by 61% versus 58% and plaque from approximal surfaces by 69% versus 65%, respectively.

CONCLUSIONS

The action of the oscillating/pulsating toothbrush with a small round brush head, Oral-B ProfessionalCare 7000, is more effective in plaque removal than the battery-operated Crest SpinBrush Pro toothbrush with a larger dual moving brush head.

Antiplaque and antigingivitis effectiveness of a hexetidine mouthwash

OBJECTIVE

To assess the antiplaque/antigingivitis efficacy of a hexetidine-containing mouthwash.

METHODS

This examiner-blind, parallel group, controlled clinical study examined the effectiveness of a hexetidine (0.1%) mouthwash both in inhibiting the development of supragingival plaque and in reducing gingivitis. One hundred and thirty-four adult subjects completed the 2-week experimental gingivitis model study. Following baseline examinations, which included plaque index, modified gingival index and gingival bleeding index, subjects received a full dental prophylaxis. Subjects were randomly assigned to one of three mouthwashes (hexetidine 0.1%, chlorhexidine 0.12% (positive control) or a 5% hydroalcohol negative control) and commenced three times daily supervised rinsing as their sole method of oral hygiene. All indices were rescored after 2 weeks.

RESULTS

Compared to the negative control group, the hexetidine group demonstrated a statistically significant inhibition and reduction of supragingival plaque and gingival inflammation with reductions of 6.3%, 33.5% and 56% for gingivitis, plaque and gingival bleeding, respectively. The results of the chlorhexidine group were used to validate the study.

CONCLUSION

The study confirms the efficacy of a hexetidine rinse in reducing supragingival plaque and gingival inflammation.

Clinical profile of tuberculosis in patients with HIV Infection/AIDS

Tuberculosis is said to be one of the commonest opportunistic infection in patients with HIV/ AIDS. A study was carried out to study the clinical, bacteriological and radiological features of HIV/TB patients. Over a period of two years, a total of 301 tuberculosis patients were suspected to have HIV/AIDS co-infection, and upon testing, 42 patients were found to be HIV seropositive. Most of the study patients were manual labourers followed by truck drivers. Sexual (heterosexual) route was found to be the major risk factor for HIV/AIDS. The most common symptom in these patients was cough and expectoration, followed by fever and weight loss. Acid-fast bacilli (AFB) smear positivity was found in 21.4% patients. On chest skiagram, infiltrative lesions were commonly seen in 61.9% patients. Extra-pulmonary tubercular manifestations were seen in 45.6% of HIV/TB cases.

Safety and plaque removal efficacy of a battery-operated power toothbrush and a manual toothbrush

PURPOSE

To compare the safety and plaque removal efficacy of a battery-operated power toothbrush and a reference adult manual toothbrush.

MATERIALS AND METHODS

This was a single-blind, randomized, split-mouth study. The power toothbrush studied was the Braun Oral-B Battery toothbrush (D4) and this was compared with a standard reference ADA manual toothbrush. The D4 toothbrush is derived from the Plaque Remover range of toothbrushes and has an oscillating/rotating action. At an initial visit, subjects (n = 48) were given a baseline examination of the oral hard and soft tissues and were instructed in the use of the D4. After one week during which subjects used the D4 at home, they returned to the test facility having abstained from oral hygiene for 23-25 hours. Two contralateral quadrants of the mouth were then randomly assigned to be cleaned with each toothbrush. Plaque assessments and hard and soft tissue examinations were made before and after brushing each quadrant for 15 seconds. Plaque was evaluated using the Rustogi modification of the Navy Plaque Index.

RESULTS

Plaque levels were significantly reduced for all sites, marginal sites and approximal sites by both toothbrushes (P < 0.0001), but the efficacy of the D4 was significantly greater than that of the ADA manual brush for all comparisons (P < 0.0001). The greatest difference between the two toothbrushes was at approximal sites where the D4 removed 19% more plaque than the manual toothbrush. For all sites, the D4 was 14% more effective, while at marginal sites the difference in favor of the D4 was 12%.

Clinical evaluation of the efficacy of a battery-powered toothbrush. results from two independent studies

PURPOSE

To compare the clinical efficacy with respect to plaque removal of a battery-operated power toothbrush (Dr. Johns Spin Brush Classic) with two manual toothbrushes, a standard ADA flat trim reference brush and the Oral-B CrossAction toothbrush.

MATERIALS AND METHODS

Efficacy was evaluated in two independent studies using a randomized, single-use, cross-over design. Healthy adult subjects from a general population brushed their teeth for a timed 1 min and plaque was scored before and after brushing was completed. In Study 1 (Spin Brush vs. ADA toothbrush), plaque was scored using the modified Quigley and Hein Plaque Index, while in Study 2 (Spin Brush vs. CrossAction) plaque was scored using the Modified Navy Plaque Index. In addition, a hard and soft tissue examination was carried out before and after brushing to allow evaluation of safety.

RESULTS

In Study 1, both the ADA toothbrush and the Spin Brush significantly reduced levels of whole mouth and approximal plaque (P < 0.0005); however, the Spin Brush was not significantly more effective than the manual brush. Relative plaque reduction for the whole mouth was 35.6 +/- 16.0% for the Spin Brush compared to 38.9 +/- 14.9% for the manual toothbrush (P < 0.047), and, for the approximal surfaces, 32.7 +/- 14.6% and 36.3 +/- 13.7%, respectively (P = 0.024). In Study 2, both toothbrushes significantly reduced plaque levels (P < 0.0001), but, as for Study 1, the CrossAction manual toothbrush was more effective than the Spin Brush. For whole mouth, marginal and approximal sites, respectively, the Spin Brush reduced plaque by 54.3%, 43.5% and 62.0%, compared with 58.6%, 47.5% and 67.1% for the CrossAction toothbrush. The difference in favor of the CrossAction brush was statistically significant (P < 0.0005) for all areas.

An evaluation of a commercial chewing gum in combination with normal toothbrushing for reducing dental plaque and gingivitis

New evidence suggests a beneficial outcome to chewing a sugarless gum as an added component to a regular, twice-daily toothbrushing regimen. Results of a 4-week study performed on 78 adults with preexisting gingivitis showed a significant reduction of dental plaque and gingivitis when the test group of 39 adults chewed 2 pieces of ARM & HAMMER Dental Care The Baking Soda Gum (AHDC)--a sugar-free chewing gum containing sorbitol, malitol, xylitol, and sodium bicarbonate--for 20 minutes twice a day in conjunction with once-daily toothbrushing for 60 seconds. The control group, also comprised of 39 adults, used breath mints (the study placebo) twice a day in conjunction with the same toothbrushing regimen. There were no statistically significant differences in plaque and gingivitis scores at the baseline examination. Using the Quigley-Hein Plaque Index, the test group experienced a 17% reduction in plaque over 4 weeks, while the control group reduced their plaque amounts by approximately 9% over the same period. Lobene's Mean Gingivitis Index scores were equally significant: a nearly 10% decline for the test group compared to almost 2% for the control group. This article describes the 4-week study and its promising results.

A graphic display for the presentation of site-wise odds ratios for score transitions to augment the traditional findings from clinical studies employing dental indexes

Many of the parameters used in clinical dental research involve the assessment of a condition at each of a number of sites within the mouth. Traditionally, such measurements are averaged over all sites within the mouth (or over all sites of a specified type) for each study participant before statistical analysis. However, a consideration of the original, site-wise scores may provide some additional insights into the performance of therapeutic modalities that might not be made evident through an application of the traditional, means-based approach. A method based on the calculation of site-wise odds ratios of certain types of baseline-to-final examination score transitions was applied to the modified gingival index data from two clinical studies performed to investigate the effect of the daily chewing of a commercially available chewing gum relative to a mint control. A graphical display of these site-specific findings was prepared, which indicated that the chewing gum regimen tended to be associated with a higher frequency of occurrence of favorable score transitions than was the mint control at several measurement sites throughout the mouth.

Comparative efficacy of an antiseptic mouthrinse and an antiplaque/antigingivitis dentifrice

BACKGROUND

The efficacy of an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic, Pfizer) and an antiplaque/antigingivitis dentifrice (Colgate Total, Colgate-Palmolive) has been demonstrated in numerous double-blind clinical studies. This study was conducted to determine their comparative efficacy.

METHODS

Three hundred sixteen subjects with mild-to-moderate gingival inflammation and plaque received a dental prophylaxis and began their randomly assigned brushing and rinsing regimen in an unsupervised setting. Subjects brushed for one minute and rinsed with 20 milliliters for 30 seconds twice daily for six months. The three groups were L (control toothpaste/Listerine rinse), T (Colgate Total toothpaste/control rinse) and P (control toothpaste/control rinse).

RESULTS

Subjects in the L and T groups demonstrated statistically significantly lower (P < .001) Modified Gingival Index, or MGI; Bleeding Index, or BI; and Plaque Index, or PI, at both three and six months than subjects in the P group. The magnitude of reduction for the L group was 22.9 percent, 70 percent and 56.1 percent, respectively, and for the T group, 20.8 percent, 58 percent and 22.1 percent, respectively. Subjects in the L group were not different from subjects in the T group in regard to visual signs of gingivitis (MGI), but were more effective (P < .001) than subjects in the T group in experiencing reduced BI and PI. No product-related adverse events were reported.

CONCLUSION

Although the Listerine Antiseptic and Colgate Total antiplaque/antigingivitis products produced similar, clinically significant reductions in gingivitis (as measured by MGI and BI), Listerine, when used in conjunction with a fluoride dentifrice and usual oral hygiene, provided a greater benefit in reducing plaque.

CLINICAL IMPLICATIONS

When considering an antiplaque/antigingivitis product to recommend to patients, clinicians should consider Listerine Antiseptic, in conjunction with usual oral hygiene, if more rigorous plaque control is desired.

Clinical effectiveness of essential oil-containing dentifrices in controlling oral malodor

PURPOSE

To assess the efficacy of two essential oil-containing dentifrices in the reduction of human intrinsic oral malodor ("morning bad breath").

MATERIALS AND METHODS

Two clinical trials were conducted which used observer-blind, negative control, parallel designs. To insure a homogeneous test population with similar oral odor characteristics, subjects followed instructions that included toothbrushing with a standard ADA-accepted fluoride dentifrice the night before. On odor evaluation days, subjects refrained from all oral hygiene procedures and from eating or drinking any food or beverage or smoking prior to and during the odor evaluations. Eighty healthy adult subjects in the first trial and 90 in the second trial with qualifying baseline levels of oral malodor participated. Odor ratings of each subject's breath were made by 4-5 trained judges using a nine point hedonic scale, i.e., 1 = most pleasant, 5 = neutral, 9 = most unpleasant. Qualifying subjects were randomly assigned one of two essential oil dentifrices or a negative control dentifrice. Subjects brushed with their assigned dentifrice for 60 s, rinsed with 20 ml of water for 10 s, and received post-treatment hedonic odor ratings at 30, 60, 90, 120, 180, and 240 min. Data were analyzed using an ANCOVA to adjust for baseline scores.

RESULTS

The essential oil dentifrices were significantly more effective (P < or = 0.033) than the control in reducing intrinsic oral malodor from 90 to 120 min.

The clinical effectiveness of a dentifrice containing triclosan and a copolymer for controlling breath odor measured organoleptically twelve hours after toothbrushing

The objective of this double-blind clinical study was to investigate the effectiveness of a dentifrice containing triclosan and a copolymer, Colgate Total Toothpaste, for controlling breath odor twelve hours after brushing the teeth compared to a placebo dentifrice which did not contain triclosan or a copolymer. Breath odor was evaluated by a panel of four expert judges using a nine-point hedonic scale. Following a baseline evaluation of breath odor, prospective study subjects who presented scores above the threshold value for unpleasant breath odor were stratified by score, and randomized into two treatment groups. Subjects were provided with a soft-bristled toothbrush, and brushed their teeth thoroughly in their regular and customary manner with their assigned dentifrice. Subjects refrained from dental hygiene, breath mints, or mouth rinses for the next twelve hours, after which they were once again evaluated for breath odor. Sixty-three (63) adult male and female subjects from the Mississauga, Ontario, Canada area participated in the study. At twelve hours after brushing their teeth, subjects in both dentifrice treatment groups presented mean breath odor scores which were statistically significantly lower than the mean scores observed at baseline. However, the difference between the mean twelve-hour breath odor scores differed significantly between the two dentifrices. The mean twelve-hour breath odor score for the Colgate Total Toothpaste group was 4.77, which is within the range of values corresponding to pleasant breath odor; the mean twelve-hour breath odor score for the placebo group was 6.05, which is above the value corresponding to unpleasant breath odor. Thus, the results of this double-blind clinical study support the conclusion that Colgate Total Toothpaste provides effective control of breath odor at twelve hours after brushing the teeth.

A short-term brushing model for assessing antiplaque/antigingivitis dentifrice effectiveness: a pilot study

This pilot clinical study was conducted to evaluate the utility of a short-term brushing model for assessing the inhibition of supragingival plaque and gingivitis by an essential oil-containing dentifrice formulation. Forty-two qualifying subjects entered and completed this double-blind, parallel group, controlled study. At baseline, subjects received an oral soft and hard tissue examination and were also scored for plaque, gingivitis and bleeding, both visually and invasively. Subjects received a supragingival prophylaxis and were randomly assigned to an experimental essential oil-containing dentifrice or its vehicle control. Subjects brushed unsupervised for one minute, twice daily for three weeks, after which all clinical examinations were repeated. All examinations were performed by a qualified and calibrated examiner. Analyses of covariance were used to compare inter-group means for each of the three outcome variables. Compared to its vehicle control, the experimental dentifrice produced statistically significant (p < 0.0001) reductions of 39.6% for plaque, 10.8% for gingivitis, and 65.4% for bleeding. No adverse events were observed or reported. The results of this pilot study suggest that three weeks of conventional use may be an adequate duration to demonstrate effectiveness of an essential oil-containing dentifrice. Confirmation of these results in a duplicate study is desirable to assess the reliability of the model. Furthermore, the utility of this model to determine the effects of formula modifications to the antiplaque and antigingivitis activity of active agents needs to be explored.

An advanced toothbrush with improved plaque removal efficacy

PURPOSE

To compare the plaque removal efficacy and safety of a new advanced manual toothbrush, the Oral-B CrossAction, with seven other toothbrushes.

MATERIALS AND METHODS

Seven independent, cross-over design clinical studies were conducted using the same examiner who was blind to the identity of the test products and treatment assignments. In each study, approximately 75 healthy adult subjects from a general population brushed with their randomly assigned toothbrush (CrossAction or comparison brush) at Visit 1 for 1 min without supervision or instruction in brushing technique. Subjects returned after a 1-week washout period and brushed with the alternate toothbrush (Visit 2). Plaque was evaluated before and after brushing using the Rustogi Modified Navy Plaque Index. Statistical analyses were conducted by an independent statistician who remained blind to the identity of all test products.

RESULTS

Each of the toothbrushes tested provided significant (P < or = 0.0001) reductions in plaque scores after a single brushing. In each of the studies, the CrossAction toothbrush removed significantly (P < or = 0.0001) greater amounts of whole mouth, gingival margin, and approximal plaque than the compared toothbrush. All toothbrushes were found to be safe, with no changes in oral tissues or restorations observed over the course of each study. The results from these studies were consistent, demonstrating that the CrossAction toothbrush significantly enhances the ability of subjects to remove more plaque during normal brushing compared to seven other toothbrushes.

A 3-month comparative investigation of the safety and efficacy of a new toothbrush: results from two independent clinical studies

PURPOSE

To compare the efficacy of a new toothbrush featuring a novel brush head design with those of two established toothbrushes by measuring plaque and gingivitis over a period of 12 weeks.

MATERIALS AND METHODS

The Oral-B CrossAction toothbrush was compared with the Dr. Best InterDent and Crest DeepSweep toothbrushes in two independent, parallel-group, examiner-blind clinical studies. Each study involved approximately 100 healthy individuals from a general population. At baseline, after 23-25 hrs of no oral hygiene, oral hard and soft tissues were examined and whole mouth, marginal and approximal plaque scores and whole mouth gingivitis scores were recorded. Subjects in the two studies were asked to use their assigned toothbrush twice a day. No instruction in brushing technique or brushing time was given. After a period of 6 weeks and finally after 12 weeks, subjects in the studies were reassessed for oral tissue status, and their plaque and gingival indices were rescored.

RESULTS

In each of the two studies, the tested toothbrushes significantly reduced levels of plaque and gingivitis. The CrossAction toothbrush was, however, more effective in reducing both plaque and gingivitis over 12 weeks, the differences in favor of the CrossAction being statistically significant. All the toothbrushes tested in this investigation were found to be safe with no evidence of hard or soft tissue trauma.

A comparison of the Braun Oral-B 3D plaque remover and the Sonicare plus electric toothbrush in removing naturally occurring extrinsic staining

PURPOSE

To compare the extrinsic stain-removing properties and the safety of the Braun Oral-B 3D Plaque Remover and the Sonicare Plus electric toothbrush.

MATERIALS AND METHODS

This randomized, parallel group, investigator-blinded study involved 67 subjects and was conducted over 6 weeks. After recruitment, the subjects received a baseline stain assessment (Lobene stain index) and a soft and hard tissue examination, and were then randomized to use either the Sonicare or the 3D device. All subjects were trained to use both devices, and instructed to brush twice daily with their assigned device for 2 min. The subjects' brushing technique was checked after 2 weeks. After a further 4 weeks, the subjects underwent a final stain assessment and soft and hard tissue examination. A questionnaire was also completed.

RESULTS

At 6 weeks, oral hard and soft tissue examinations revealed no abrasion or damage in either group. Both brushes produced significant (P < 0.001) reductions from baseline in total stain score, stain area and intensity, but group comparisons showed that these reductions were significantly (P < 0.001) greater for the 3D device.

Identification of bovine sperm specific polypeptides reactive with antisperm antibodies

The present study was taken to characterize molecular weights of sperm specific polypeptides antigenic to rabbits and calf with the aim to assess their immunoreactivity with IgG antibodies in sera from immuno-infertile cows. Seropositivity for antisperm IgG antibodies in 75 repeat breeder and 15 pregnant control cattle was tested by cellular ELISA using washed spermatozoa antigen from 4 bulls. Molecular weights of bovine sperm polypeptides antigenic to rabbit and calf were determined by 10% SDS-PAGE and Western blotting. Molecular weights of sperm peptides reactive with sera from immuno-infertile cows were also determined. Seropositivity of antisperm IgG antibodies for bull I, II, III and IV was 23.6, 14.6, 26.6 and 20%, respectively. A total of 16 polypeptides were discernible on gel. Out of these, 7 polypeptides were immunoreactive with sera from hyperimmunized rabbits as compared to 3 poly-peptides which reacted with sera from hyper-immunized calf. Only two polypeptides were reactive with sera from immuno-infertile cows. Variable number of sperm polypeptides and their immunoreactivity have been reported in different species. Antigenicity of different polypeptides in sperm needs further investigations.

A comparison of two electric toothbrushes with respect to plaque removal and subject preference

PURPOSE

To compare the safety and plaque removal efficacy, and subject preference of two electric toothbrushes in a single-blind, randomized, split-mouth study.

MATERIALS AND METHODS

The devices studied were the Braun Oral-B 3D Plaque Remover and the sonicare electric toothbrush. The 3D toothbrush combines the clinically proven oscillating/rotating action of the D9 with a sonic frequency pulsating action in the direction of the long axis of the bristles, giving a three-dimensional cleaning action. At an initial visit, the subjects (n = 44) were given a baseline examination of the oral soft tissues and a full mouth prophylaxis and instructed in the use of the two products, which was followed by a 4-week training period. After 2 weeks of using each toothbrush on alternate days, brushing technique was checked. After a further 2 weeks, having abstained from oral hygiene for 48 hours, two contralateral quadrants of the mouth were randomly assigned to be cleaned by the subjects with each toothbrush. Plaque assessments and soft tissue examinations were made before and after brushing. Plaque was evaluated according to a refinement of the Modified Navy Plaque Index. At the end of the study, subjects completed a product evaluation questionnaire.

RESULTS

Plaque levels were significantly reduced by both toothbrushes (P = 0.001), but the efficacy of the 3D electric toothbrush was significantly greater than that of the sonicare toothbrush (P = 0.001) for all comparisons. Plaque reduction was particularly marked in the interproximal areas, reaching 87% with the 3D product, compared with 68% for sonicare (P = 0.001). In the responses to the questionnaire, the majority of subjects stated that they preferred the 3D toothbrush (88% vs 12%), mainly because of the smaller size of the brush, ease of control and overall maneuverability.

Iodine deficiency in district Kinnaur, Himachal Pradesh

The state of Himachal Pradesh is a known iodine deficiency endemic region since the last 40 years. The state government is supplying iodised salt to the district since 1970. No recent survey has been conducted on the prevalence of iodine deficiency from the district Kinnaur which is located at an average altitude of 10,000 feet above sea level. A total of 1094 children in the age group of 6-10 years were included in the study and clinically examined. The total goitre prevalence of 6.1% was found in the subjects studied. Urine samples were collected from 226 children and were analysed using standard laboratory procedures. It was found that the percentage of children with < 2 mcg/dl, 2-4.9 mcg/dl, 5-9.9 mcg/dl and 10 and above mcg/dl of urinary iodine excretion (UIE) level was 1.3, 5.8, 10.6 and 82.3 respectively. A total of 242 salt samples were collected and analysed using the standard iodometric titration method. Results showed that almost 90% of the families were consuming salt with an iodine content of 15 ppm and more which is the stipulated level of iodisation of salt. The findings of the study indicate that iodine nutrition is in the transition phase from iodine deficient to iodine sufficient. Findings revealed a need for further strengthening the monitoring of the quality of salt being distributed in Kinnaur to achieve elimination of iodine deficiency.

Isolation of Salmonella senftenberg bacteriophages

A total of 61 bacteriophages were isolated from 100 strains of Salmonella senftenberg. Six bacteriophages were selected for typing purposes which were specific for S. senftenberg. Five phages, SasL1 to SasL5 were morphologically similar; phage SasL6 was morphologically different from the others. These phages fall into two morphological groups none of which correspond to the known tailed enterobacterial phage species. Hence, two new phage species represented by SasL1 and SasL6 are proposed.

Adjuvant effect of DEAE-dextran and tetanus toxoid on whole cell heat inactivated phenol preserved typhoid vaccine

Active mouse protection test (AMPT) and enzyme linked immunosorbent assay (ELISA) were used to determine the immunogenicity of whole cell typhoid vaccine when administered in conjunction with either tetanus toxoid (TT) or DEAE-Dextran (DD). Immunization of mice with whole cell typhoid vaccine showed enhanced potency either when administered in conjunction with TT or DD and values were statistically significant (p < 0.05) in comparison to conventional or standard typhoid vaccines. For ELISA, the mice were immunized with 2 different schedules, one in which a single dose of 0.25 ml subcutaneously (s/c) was administered and in another two doses of 0.25 ml each s/c, 14 days apart. In case of single dose schedule of immunization D vaccine (Whole cell typhoid + 5 mg/ml DD) showed significant increase of immune response (3.201 log10) as compared to plain vaccine (2.550 log10). Two dose schedule further increased the titres to 3.856 log10. DD adjuvanted vaccine showed higher potency by AMPT as compared to the TT adjuvanted vaccine or plain vaccine. The present study clearly demonstrates that a single dose of 0.25 ml which is equivalent to half of the conventionally used single human dose of typhoid vaccine adjuvanted with DD can significantly improve the immunogenicity of the vaccine.