The Oral Microbiome and Cross-Kingdom Interactions during Pregnancy.

Pregnancy initiates a temporary transition in the maternal physiological state, with a shift in the oral microbiome and a potential increase in frequency of oral diseases. The risk of oral disease is higher among populations of Hispanic and Black women and those with lower socioeconomic status (low SES), demonstrating a need for intervention within these high-risk populations. To further our understanding of the oral microbiome of high-risk pregnant women, we characterized the oral microbiome in 28 nonpregnant and 179 pregnant low-SES women during their third trimester living in Rochester, New York. Unstimulated saliva and supragingival plaque samples were collected cross-sectionally, followed by assessment of the bacterial (16S ribosomal RNA) and fungal (18S ITS) microbiota communities. Trained and calibrated dentists performed oral examinations to determine the number of decayed teeth and plaque index. Initially, plaque from 28 nonpregnant women and 48 pregnant women were compared; these data showed significant differences in bacterial abundances based on pregnancy status. To further our understanding of the oral microbiome within the pregnant population, we next examined the oral microbiome within this population based on several variables. Streptococcus mutans, Streptococcus oralis, and Lactobacillus were associated with a greater number of decayed teeth. The composition of fungal communities differed between plaque and saliva, demonstrating 2 distinct "mycotypes" that were represented by a greater abundance of Candida in plaque and Malassezia in saliva. Veillonella rogosae, a common oral bacterium, was negatively associated with both plaque index and salivary Candida albicans colonization by culture data. This was further emphasized by in vitro inhibition of C. albicans by V. rogosae. Identification of interactions between the bacterial or fungal oral communities revealed that V. rogosae was positively associated with the oral commensal Streptococcus australis and negatively with the cariogenic Lactobacillus genus, suggesting V. rogosae as a potential biomarker of a noncariogenic oral microbiome.

Association between Oral Candida and Bacteriome in Children with Severe ECC.

Candida albicans is an opportunistic fungal organism frequently detected in the oral cavity of children with severe early childhood caries (S-ECC). Previous studies suggested the cariogenic potential of C. albicans, in vitro and in vivo, and further demonstrated its synergistic interactions with Streptococcus mutans. In combination, the 2 organisms are associated with higher caries severity in a rodent model. However, it remains unknown whether C. albicans influences the composition and diversity of the entire oral bacterial community to promote S-ECC onset. With 16s rRNA amplicon sequencing, this study analyzed the microbiota of saliva and supragingival plaque from 39 children (21 S-ECC and 18 caries-free [CF]) and 33 mothers (17 S-ECC and 16 CF). The results revealed that the presence of oral C. albicans is associated with a highly acidogenic and acid-tolerant bacterial community in S-ECC, with an increased abundance of plaque Streptococcus (particularly S. mutans) and certain Lactobacillus/Scardovia species and salivary/plaque Veillonella and Prevotella, as well as decreased levels of salivary/plaque Actinomyces. Concurrent with this microbial community assembly, the activity of glucosyltransferases (cariogenic virulence factors secreted by S. mutans) in plaque was significantly elevated when C. albicans was present. Moreover, the oral microbial community composition and diversity differed significantly by disease group (CF vs. S-ECC) and sample source (saliva vs. plaque). Children and mothers within the CF and S-ECC groups shared microbiota composition and diversity, suggesting a strong maternal influence on children's oral microbiota. Altogether, this study underscores the importance of C. albicans in association with the oral bacteriome in the context of S-ECC etiopathogenesis. Further longitudinal studies are warranted to examine how fungal-bacterial interactions modulate the onset and severity of S-ECC, potentially leading to novel anticaries treatments that address fungal contributions.

Familial transmission of leprosy in post-war Britain--discrimination and dissent.

A Polish immigrant, who was resident in the United Kingdom (UK), presented with lepromatous leprosy and was detained in two hospitals against his wishes in the late 1940s. The public reaction to his diagnosis was remarkable, with street riots and questions in the Houses of Parliament about 'this leper'. His wife was persecuted and had to change her name. The index patient died of tuberculosis during enforced isolation in hospital, and several years later his daughter (who had never left the UK) presented with a left median nerve palsy and probable lepromatous dactylitis of the left third finger, eventually requiring amputation and prolonged dapsone treatment. Her disease resolved slowly but completely. We believe these two familial cases represent the first documented episode of autochthonous leprosy transmission in the UK since the early 1920s. They also demonstrate the ability of this disease to engender fear, dissent and discrimination amongst the public. Parallels are drawn with reactions to the cholera epidemics in nineteenth century Britain, and to HIV/AIDS, SARS and multi-drug resistant tuberculosis in more recent times.

Leprosy in Britain: 50 years experience in Liverpool.

BACKGROUND: Leprosy is a chronic infection that presents with varying dermal and neurological symptoms, and which can lead to extensive disability and morbidity, often with accompanying social stigma. AIM: To review the patients presenting to the Liverpool School of Tropical Medicine (LSTM) between 1946 and 2003, looking specifically at country of birth and of infection, details of clinical presentation, diagnosis, management and reactions. DESIGN: Retrospective record review. METHODS: We retrieved all available clinical records for patients seen between 1946 and 2003 (n = 50), consisting of letters, hospital and LSTM casenotes, and some radiographs and photographs. Any history of tuberculosis or diabetes was recorded. RESULTS: Most patients (64%) were born in the Indian subcontinent, and most were thought to have contracted the disease there (62%). Features at presentation included anaesthetic skin lesions in 19 (36%), hypopigmentation in 15 (30%), and peripheral nerve enlargement in 25 (50%). Diagnoses were made by a combination of clinical data and biopsy (60%), and slit skin smears were positive for acid-fast bacilli in 61% of multibacillary patients. Initial presentation was with a leprosy reaction in five cases (10%), and reactions were documented in 42% of all patients. Treatments were varied, progressing from traditional Eastern medicine to the WHO-approved multidrug therapy in use today, with prophylaxis for children and close contacts. DISCUSSION: Leprosy remains an important diagnosis to consider in patients with a history of work or travel in the tropics, and is a diagnosis with far-reaching medical, social and emotional consequences.

Leprosy in Britain: 50 years experience in Liverpool

BACKGROUND: Leprosy is a chronic infection that presents with varying dermal and neurological symptoms, and which can lead to extensive disability and morbidity, often with accompanying social stigma. AIM: To review the patients presenting to the Liverpool School of Tropical Medicine (LSTM) between 1946 and 2003, looking specifically at country of birth and of infection, details of clinical presentation, diagnosis, management and reactions. DESIGN: Retrospective record review. METHODS: We retrieved all available clinical records for patients seen between 1946 and 2003 (n = 50), consisting of letters, hospital and LSTM casenotes, and some radiographs and photographs. Any history of tuberculosis or diabetes was recorded. RESULTS: Most patients (64%) were born in the Indian subcontinent, and most were thought to have contracted the disease there (62%). Features at presentation included anaesthetic skin lesions in 19 (36%), hypopigmentation in 15 (30%), and peripheral nerve enlargement in 25 (50%). Diagnoses were made by a combination of clinical data and biopsy (60%), and slit skin smears were positive for acid-fast bacilli in 61% of multibacillary patients. Initial presentation was with a leprosy reaction in five cases (10%), and reactions were documented in 42% of all patients. Treatments were varied, progressing from traditional Eastern medicine to the WHO-approved multidrug therapy in use today, with prophylaxis for children and close contacts. DISCUSSION: Leprosy remains an important diagnosis to consider in patients with a history of work or travel in the tropics, and is a diagnosis with far-reaching medical, social and emotional consequences.

High-pressure treatment of milk: effects on casein micelle structure and on enzymic coagulation.

High isostatic pressures up to 600 MPa were applied to samples of skim milk before addition of rennet and preparation of cheese curds. Electron microscopy revealed the structure of rennet gels produced from pressure-treated milks. These contained dense networks of fine strands, which were continuous over much bigger distances than in gels produced from untreated milk, where the strands were coarser with large interstitial spaces. Alterations in gel network structure gave rise to differences in rheology with much higher values for the storage moduli in the pressure-treated milk gels. The rate of gel formation and the water retention within the gel matrix were also affected by the processing of the milk. Casein micelles were disrupted by pressure and disruption appeared to be complete at treatments of 400 MPa and above. Whey proteins, particularly beta-lactoglobulin, were progressively denatured as increasing pressure was applied, and the denatured beta-lactoglobulin was incorporated into the rennet gels. Pressure-treated micelles were coagulated rapidly by rennet, but the presence of denatured beta-lactoglobulin interfered with the secondary aggregation phase and reduced the overall rate of coagulation. Syneresis from the curds was significantly reduced following treatment of the milk at 600 MPa, probably owing to the effects of a finer gel network and increased inclusion of whey protein. Levels of syneresis were more similar to control samples when the milk was treated at 400 MPa or less.

The continuous isolation of trypsin by affinity adsorbent recycling.

A method for the continuous affinity separation of proteins is described in which the adsorbent, in the form of a polymer belt, is recycled through feedstock and eluent liquid flows. As the belt is nonporous, contact between the solute and the ligand is not diffusion-dependent. Consequently, rapid cycle rates are possible. Soybean trypsin inhibitor immobilized on nylon was used as an affinity ligand for the isolation of trypsin. During a 30-h continuous run, trypsin was isolated from a crude preparation of bovine pancreas with a recovery of 30% to 40%. Approximately 18 mg of trypsin was obtained from 500 mg of protein using a total of approximately 10 mug of ligand. Electrophoretic analysis of the eluent showed that chymotrypsin, which also binds to SBTI, was the only major contaminant of the product. It was demonstrated that the highest rates of protein purification were obtained using solid/liquid contact times well below that required to achieve saturation of the affinity adsorbent. Slower adsorbent recycle rates, which achieved higher protein binding per unit area of belt, resulted in lower protein purification per unit time. The rate of purification was also dependent on the concentration of target protein in the adsorption chamber at steady state. As high concentrations increased losses from the chamber outflow, this resulted in a compromise between throughput and recovery during the adsorption phase. Under the conditions investigated, recoveries of over 60% were obtained, and a maximum throughput of approximately 2.5 mg trypsin per hour was achieved. Preliminary studies have shown that this can be improved by compartmentalizing the adsorption chamber, which can reduce losses from the adsorption chamber to less than 5%. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 538-545, 1997.