Effectiveness of Manual Toothbrushing Techniques on Plaque and Gingivitis: A Systematic Review.

PURPOSE: Currently, there is no consensus on recommendations for manual toothbrushing techniques between dentists, oral health therapists and dental companies. The aim of this systematic review is to identify and assess the quality of evidence of the effectiveness of manual toothbrushing techniques in the existing literature. METHODS: A broad search was conducted on the electronic databases Medline via Ovid, PubMed and EBSCO Dentistry & Oral Sciences. Included studies examined manual toothbrushing technique efficiency. Articles were assessed utilising the Cochrane Collaboration's tool for assessing risk of bias. Thirteen studies met the inclusion criteria and were included in this review. These included five randomised controlled trials (RCT), seven experimental non-randomised control studies and one in vitro study. RESULTS: Of the 3190 articles identified, 40 were relevant to manual toothbrushing and 13 were included in the final review. Studies indicating statistically significantly superior plaque removal for a given technique were Bass (one), modified Bass (one), Charter's (two), Fones (two), scrub (two), roll (one), modified Stillman (one), toothpick method (one). Four studies exhibited no statistically significant difference in effectiveness of plaque removal. Unfortunately, considerable variation was found between studies, making a definitive conclusion impossible in terms of an ideal manual toothbrushing technique that would promote plaque removal and reduce gingivitis. CONCLUSION: There is still insufficient evidence for suggesting that one toothbrushing method is more effective than another in plaque removal and reduction of gingivitis. Excessive variability in many aspects of the design and methodology of the selected studies hinder conclusions on an ideal manual toothbrushing technique. Experimental randomised controlled trials that follow the CONSORT guidelines are required to provide adequate-quality evidence and make any definitive conclusions on the relative effectiveness of manual toothbrushing techniques.

Hepatitis E virus infection in Hong Kong blood donors.

BACKGROUND AND OBJECTIVES: In Hong Kong, the dominant circulating hepatitis E virus (HEV) genotype is type 4, which can cause more severe clinical consequences than type 3. The aim of this study was to determine the HEV prevalence in Hong Kong blood donors. MATERIALS AND METHODS: Unlinked donation samples (n = 10 000) collected in March to May 2015 were tested for HEV RNA using the Procleix HEV assay in an individual donation format (IDT). A subset of 2000 samples were tested for IgG and IgM anti-HEV using the Wantai enzyme-linked immunosorbent assay (ELISA). Nucleic acid testing (NAT) initial reactive results were retested once, and repeatedly reactive donations were subjected to alternative molecular procedures as confirmation tests. RESULTS: One in 5000 Hong Kong blood donors was positive for HEV RNA (0·02%). The two RNA positive samples were also IgG and IgM anti-HEV positive. One of the two RNA positive donors could be sequenced revealing genotype type 4. Anti-HEV seroprevalence was estimated as 15·5% among all donors. IgG anti-HEV positive rate for age group 16-20 was 3·1%, and it increased with age to 43·1% for age group 51-60. Sero-positivity was higher in males (male donors 18·1% vs. female donors 13·2%), but it was mostly due to the difference in a specific age group (41-50). CONCLUSION: Hepatitis E virus RNA positive rate of 0·02% was within the reported range of HEV RNA frequency in developed countries. One donor was confirmed to be genotype 4, which is the dominant genotype in circulation in Hong Kong.

Characterization of SARS-CoV main protease and identification of biologically active small molecule inhibitors using a continuous fluorescence-based assay.

Severe acute respiratory syndrome associated coronavirus main protease (SARS-CoV Mpro) has been proposed as a prime target for anti-SARS drug development. We have cloned and overexpressed the SARS-CoV Mpro in Escherichia coli, and purified the recombinant Mpro to homogeneity. The kinetic parameters of the recombinant SARS-CoV Mpro were characterized by high performance liquid chromatography-based assay and continuous fluorescence-based assay. Two novel small molecule inhibitors of the SARS-CoV Mpro were identified by high-throughput screening using an internally quenched fluorogenic substrate. The identified inhibitors have Ki values at low microM range with comparable anti-SARS-CoV activity in cell-based assays.

Identification of novel small-molecule inhibitors of severe acute respiratory syndrome-associated coronavirus by chemical genetics.

The severe acute respiratory syndrome-associated coronavirus (SARS-CoV) infected more than 8,000 people across 29 countries and caused more than 900 fatalities. Based on the concept of chemical genetics, we screened 50,240 structurally diverse small molecules from which we identified 104 compounds with anti-SARS-CoV activity. Of these 104 compounds, 2 target the SARS-CoV main protease (M(pro)), 7 target helicase (Hel), and 18 target spike (S) protein-angiotensin-converting enzyme 2 (ACE2)-mediated viral entry. The EC(50) of the majority of the 104 compounds determined by SARS-CoV plaque reduction assay were found to be at low micromolar range. Three selected compounds, MP576, HE602, and VE607, validated to be inhibitors of SARS-CoV M(pro), Hel, and viral entry, respectively, exhibited potent antiviral activity (EC(50) < 10 microM) and comparable inhibitory activities in target-specific in vitro assays.

Phenotypic and molecular characterization of erythromycin resistance in four isolates of Streptococcus-like gram-positive cocci causing bacteremia.

Among nine patients with bacteremia caused by Granulicatella or Gemella in a 6-year period (July 1995 to June 2001), three had bacteremia caused by erythromycin-resistant Granulicatella adiacens and one had bacteremia caused by erythromycin-resistant Gemella haemolysans. All four isolates possessed mef genes, whereas none possessed ermT, ermTR, or ermB genes.

Lack of evidence that DNA in antibiotic preparations is a source of antibiotic resistance genes in bacteria from animal or human sources.

Although DNA encoding antibiotic resistance has been discovered in antibiotic preparations, its significance for the development of antibiotic resistance in bacteria is unknown. No phylogenetic evidence was obtained for recent horizontal transfer of antibiotic resistance genes from antibiotic-producing organisms to bacteria from human or animal sources.

Clinical and molecular epidemiology of erythromycin-resistant beta-hemolytic lancefield group G streptococci causing bacteremia.

Among 100 patients with group G beta-hemolytic streptococcal bacteremia in a 6-year period (1997 to 2002), seven had bacteremia caused by erythromycin-resistant strains. Five of the seven patients had cellulitis and/or abscesses. The two isolates resistant to erythromycin and clindamycin possessed erm genes, one ermTR and the other ermB. The five isolates resistant to erythromycin but sensitive to clindamycin and one of those resistant to both erythromycin and clindamycin possessed mef genes.

Molecular characterization of a strain of group a streptococcus isolated from a patient with a psoas abscess.

We report the first case of a primary group A streptococcus (GAS) psoas abscess in a 31-year-old woman. The psoas abscess was preceded by an episode of acute pharyngitis. The M-protein gene (emm) and streptolysin S structural gene (sagA) were present in the isolate, with no significant amino acid differences from previously described sequences of M1 GAS isolates. Multilocus sequence typing (MLST) showed that the isolate belonged to MLST sequence type (MLST-ST) 28, the predominant MLST-ST associated with invasive disease caused by M1 isolates.

Geographical difference of disease association in Streptococcus bovis bacteraemia.

From 1996 to 2001, 48 Streptococcus bovis strains were isolated from blood cultures of 37 patients in one hospital. Median patient age was 68 years (range: 1 day-88 years). The male : female ratio was 23 : 14. Most patients (97 %) had underlying diseases, including biliary tract disease in 14 (38 %), diabetes mellitus in 12 (32 %), liver parenchymal disease in seven (19 %), carcinoma of the colon in four (11 %) and other malignancies in four (11 %). No infective foci (indicative of primary bacteraemia) were identified in 15 patients (40 %) and 14 (38 %) had acute cholangitis/cholecystitis, but only four (11 %) had infective endocarditis. Two (5 %), three (8 %) and 32 (87 %) patients had S. bovis of biotypes I, II/1 and II/2, respectively, and three (8 %), two (5 %) and 32 (87 %) patients had S. bovis of genotypes 1, 2a and 2b, respectively. All isolates were sensitive to penicillin, cephalothin and vancomycin, 24 (65 %) were resistant to erythromycin and 15 (41 %) were resistant to clindamycin (these strains were also resistant to erythromycin). Thirteen isolates that were erythromycin- and clindamycin-resistant possessed the ermB gene, 10 possessed the ermT gene and one possessed both the ermB and ermT genes. Overall, seven patients (19 %) died. In contrast to most other reports from western countries, where carcinoma of the colon and infective endocarditis were the major underlying disease and infective focus associated with S. bovis bacteraemia, biliary tract disease and acute cholangitis and/or cholecystitis were the major underlying diseases associated with S. bovis bacteraemia in our locality.