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Our previous analysis of 65 advanced dental caries lesions by traditional culture techniques indicated that lactobacilli were numerous in the advancing front of the progressive lesion. Production of organic acids by lactobacilli is considered to be important in causing decalcification of the dentinal matrix. The present study was undertaken to define more precisely the diversity of lactobacilli found in this environment and to quantify the major species and phylotypes relative to total load of lactobacilli by real-time PCR. Pooled DNA was amplified by PCR with Lactobacillus genus-specific primers for subsequent cloning, sequencing, and phylogenetic analysis. Based on 16S ribosomal DNA sequence comparisons, 18 different phylotypes of lactobacilli were detected, including strong representation of both novel and gastrointestinal phylotypes. Specific PCR primers were designed for nine prominent species, including Lactobacillus gasseri, L. ultunensis, L. salivarius, L. rhamnosus, L. casei, L. crispatus, L. delbrueckii, L. fermentum, and L. gallinarum. More than three different species were identified as being present in most of the dentine samples, confirming the widespread distribution and numerical importance of various Lactobacillus spp. in carious dentine. Quantification by real-time PCR revealed various proportions of the nine species colonizing carious dentine, with higher mean loads of L. gasseri and L. ultunensis than of the other prevalent species. The findings provide a basis for further characterization of the pathogenicity of Lactobacillus spp. in the context of extension of the carious lesion.Dental caries continues to be a significant public health problem in many parts of the world. Although the bacteria responsible for caries initiation and early caries progression have been studied extensively, the microbiology of dentine caries has been reported to show considerable diversity and has not yet been fully characterized. Dissolution by acid of the surface enamel exposes the underlying avascular mineralized connective tissue matrix of dentine, which is prone to invasion. This occurs by migration of bacteria into the network of tubules occupied by processes of the pulpal odontoblasts. The early stage of invasion involves lactobacilli, Actinomyces spp., veillonellae, and mutans streptococci (for a review, see reference 19). This phase is followed by the invasion of a more diverse group of microorganisms including gram-negative anaerobes. There is evidence that interspecies cooperation enhances the migration of the mixed bacterial flora through the dentinal tubules (20,27).Lactobacilli have been reported to occur in high numbers in both superficial and deep caries (9), though they are not suspected of being involved in bacterial invasion of nonexposed dental pulp (12). Our previous analysis of lactobacilli by culture under microaerophilic conditions in 65 deep caries samples indicated that Lactobacillus acidophilus was numerically dominant, although Lactobacillus paracasei, Lactobacillus rhamnosus, and Lact...

Real-time PCR analysis of the total bacterial load in advanced carious lesions has shown that the total load exceeds the number of cultivable bacteria. This suggests that an unresolved complexity exists in bacteria associated with advanced caries. In this report, the profile of the microflora of carious dentine was explored by using DNA extracted from 10 lesions selected on the basis of comparable total microbial load and on the relative abundance of Prevotella spp. Using universal primers for the 16S rRNA gene, PCR amplicons were cloned, and approximately 100 transformants were processed for each lesion. Phylogenetic analysis of 942 edited sequences demonstrated the presence of 75 species or phylotypes in the 10 carious lesions. Up to 31 taxa were represented in each sample. A diverse array of lactobacilli were found to comprise 50% of the species, with prevotellae also abundant, comprising 15% of the species. Other taxa present in a number of lesions or occurring with high abundance included Selenomonas spp., Dialister spp., Fusobacterium nucleatum, Eubacterium spp., members of the Lachnospiraceae family, Olsenella spp., Bifidobacterium spp., Propionibacterium sp., and Pseudoramibacter alactolyticus. The mechanisms by which such diverse patterns of bacteria extend carious lesions, including the aspect of infection of the vital dental pulp, remain unclear.

Background: Nasal colonisation with otitis media (OM) pathogens, particularly Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, is a precursor to the onset of OM. Many children experience asymptomatic nasal carriage of these pathogens whereas others will progress to otitis media with effusion (OME) or suppurative OM. We observed a disparity in the prevalence of suppurative OM between Aboriginal children living in remote communities and non-Aboriginal children attending child-care centres; up to 60% and <1%, respectively. This could not be explained by the less dramatic difference in rates of carriage of respiratory bacterial pathogens (80% vs 50%, respectively). In this study, we measured nasal bacterial load to help explain the different propensity for suppurative OM in these two populations.

The SARS-CoV-2 epidemic has rapidly spread outside China with major outbreaks occurring in Italy, South Korea, and Iran. Phylogenetic analyses of whole-genome sequencing data identified a distinct SARS-CoV-2 clade linked to travellers returning from Iran to Australia and New Zealand. This study highlights potential viral diversity driving the epidemic in Iran, and underscores the power of rapid genome sequencing and public data sharing to improve the detection and management of emerging infectious diseases.

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AbstractThe SARS-CoV-2 epidemic has rapidly spread outside China with major outbreaks occurring in Italy, South Korea and Iran. Phylogenetic analyses of whole genome sequencing data identified a distinct SARS-CoV-2 clade linked to travellers returning from Iran to Australia and New Zealand. This study highlights potential viral diversity driving the epidemic in Iran, and underscores the power of rapid genome sequencing and public data sharing to improve the detection and management of emerging infectious diseases.

Objective.Whether patients with type 2 diabetes change their lifestyle in response to their diagnosis and maintain behavior changes is unclear. This study aimed to 1) compare changes in lifestyle behaviors among participants who were newly diagnosed with type 2 diabetes and those never diagnosed with type 2 diabetes and 2) investigate changes in lifestyle behaviors in relation to the duration of newly diagnosed type 2 diabetes.Methods.We used self-reported information from the New South Wales 45 and Up Study and a follow-up study. Changes in body weight; amount of walking, moderate to vigorous physical activity (MVPA), and sitting; fruit and vegetable consumption; and smoking status and number of cigarettes smoked were used as measures of health behavior change. These variables were compared between participants in a “new type 2 diabetes” group and a “no type 2 diabetes” group.Results.The new type 2 diabetes group had a smaller decrease in vegetable consumption, lost more weight, and were more likely to quit smoking than the no type 2 diabetes group. MVPA, fruit consumption, and number of cigarettes smoked did not change significantly for either group. Although no significant changes were found in any of the health behaviors based on time since diagnosis, the magnitude of changes in weight and walking increased as duration of diagnosis increased, whereas changes in MVPA, number of cigarettes smoked, and proportion of participants who quit smoking decreased.Conclusion.In this population-based study, participants with incident type 2 diabetes reported only minimal changes in their lifestyle factors after receiving their diagnosis.