Molecular Characterization of Fungal Colonization on the Provox™ Tracheoesophageal Voice Prosthesis in Post Laryngec-tomy Patients

Background: Tracheoesophageal voice prostheses (TVPs) have been the gold standard in rehabilitation, after laryngectomy, producing faster and premier voicing towards esophageal speech. Fungal colonization shortens the device’s lifetime and leads to prosthesis dysfunction, leakage, and subsequent respiratory infection. Therefore, in the current study, we aimed to investigate the fungal colonization patterns and to propose prophylactic measures that shall increase the longevity of voice prosthesis. Methods: Failed TVPs were removed - due to leakage and/or aspiration - from 66 post laryngectomy patients and examined. They were referred to Amiralam and Rasoul Hospital, the main centers of Ear, Nose, and Throat in Tehran, Iran from April 2018 to January 2020. Fungal colonization patterns were assessed using DNA sequencing techniques. Furthermore, the susceptibility to fluconazole, amphotericin B, nystatin, and white vinegar was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Resident fungal species from the upper airways colonized all the 66 TVPs (100%). Diabetes (31%) and smoking (98%) were the predominant underlying disease and predisposing factors, respectively. Among the 79 fungal agents isolated from the 66 TVPs, Candida glabrata (n=25, 31.7%) was the most common. A significant reduction in minimum inhibitory concentration (MIC) values were observed for white vinegar when used alone (P<0.05). Conclusion: White vinegar at a very low concentration could decrease the amount of fungal colonization on TVPs without any adverse effects; its wide accessibility and affordability ensure a decrease in the overall health cost.

Divergence in Corn Mycorrhizal Colonization Patterns Due to Organic Treatment

Excessive application of chemical fertilizers and other agrochemicals can cause large imbalances in soils and agricultural ecosystems. In this context, mycorrhizae represent a viable solution to mitigate these negative effects. Arbuscular mycorrhizae are vital symbionts due to the multiple benefits they bring to both crops and the entire agroecosystem. The main purpose of this study was to observe whether differentiated fertilization has an influence on mycorrhizal colonization patterns in corn. Observed frequencies and intensities of colonization varied widely between phenophases and treatments, with 20% variation for frequency and 14% for intensity, which implies the constant development of both partners during the vegetation period. Arbuscules and vesicles were present in all development stages, but the overall mean was lower than 4% for arbuscules and 1% for vesicles in the analyzed root fragments. Intensity was highly correlated with frequency of colonization compared with arbuscules, where the coefficient was 0.54, and vesicles, with a coefficient of 0.16. Both PCA and NMDS provided good graphical solutions, with a high resolution due to explained variance and good spatial position of vectors. The use of mycorrhizal maps permits the full exploration of colonization patterns and fungal strategy, and the assessment of mycorrhizae-free areas. For the untreated variant, the strategy was oriented toward a longitudinal colonization followed by an irregular development of hyphae with multiple non-colonized areas. Treatment acts to stimulate the appearance of mycorrhizal spots, which further develop radially.

First Report on the Benthic Invertebrate Community Associated With a Bronze Naval Ram From the First Punic War: A Proxy of Marine Biodiversity

Historical traces of organisms on the seafloor, such as shells and tubes, constitute the ecological memory of ancient benthic assemblages and serve as an important resource for understanding the assembly of modern communities. Archeological shipwrecks are particularly interesting submerged substrata for both their archeological and biological implications. For the first time, we studied the species composition and life-history traits of dominant organisms in the benthic assemblage on a bronze Carthaginian naval ram, which sank more than two thousand years ago in the Southern Tyrrhenian Sea. By comparing the species composition of the ram assemblage with those of the surrounding habitats, we inferred possible colonization patterns for the ram and discussed the informative role of the shipwreck as a proxy of marine biodiversity. The ram assemblage was rich in species, including both sessile (bryozoans, serpulid polychaetes, and few bivalves) and motile (gastropods) species. Sexual reproduction with free-spawning fertilization and long-duration larvae characterized most species. The long submersion time of the ram, together with the reproductive strategies, growth forms, and motility of the dominant species were key factors shaping the community of the ram. The ram itself offers an archeological artifact of inestimable value, but our analysis revealed it to be an effective collector of fauna from the surrounding seabed. The ram community hosted species from a range of nearby natural habitats (mostly coralligenous, detritic bottoms, and zoosteracean meadows) and thus served as a proxy for marine biodiversity on the surrounding seabed. We conclude that the presence of many species on the ram that commonly occur in adjacent habitats of great environmental value was informative and highlight the important marine biodiversity in the area of the Aegadian archipelago.

Mutans Streptococci and Lactobacilli: Colonization Patterns and Genotypic Characterization of Cariogenic Bacterial Species in American Indian Children

Aim: The purpose of this study was to investigate the presence of Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus species in an American Indian population displaying a high incidence of severe early childhood caries (S-ECC) and to explore the genotypic diversity and fidelity of transmission of S. sobrinus in this population.Methods: We report here on the microbial profiles of 71 children compiled from birth to 36 months of age and initial exploration of genotypic diversity in a subset of 40 mother/child dyads. Whole mouth plaque samples were collected from mother/child dyads in a Northern Plains American Indian cohort. Mutans streptococci (MS) and Lactobacillus counts were recorded and presence/absence of S. mutans, S. sobrinus, and Lactobacillus was noted for each child. S. sobrinus was isolated and genotyped via arbitrarily primed-polymerase chain reaction (AP-PCR).Results: The children in this study were divided into caries active (CA) and caries free (CF) groups. S. mutans, S. sobrinus, and Lactobacillus species were detected more frequently in CA groups. Distribution of MS and Lactobacillus counts was significantly different between the two groups, as was the distribution of three species colonization profiles. Twelve S. sobrinus genotypes were detected in the subset of mother/child dyads. Individual participants displayed a range of 0–3 distinct genotypes while mother/child pairs displayed a range of 1–5 genotypes. Eighty-three percent of children shared at least one genotype with his/her mother.Conclusion: Caries active children in this population display different microbial profiles than the caries free children in this cohort. A small number of S. sobrinus genotypes appear to be very common in this population. A high rate of vertical transmission of S. sobrinus from mother to child is seen in these mother/child dyads.

Contagious Ovine Digital Dermatitis: A Novel Bacterial Etiology and Lesion Pathogenesis

Contagious ovine digital dermatitis (CODD) is a severe and common infectious foot disease of sheep and a significant animal welfare issue for the sheep industry in the UK and some European countries. The etiology and pathogenesis of the disease are incompletely understood. In this longitudinal, experimental study, CODD was induced in 18 sheep, and for the first time, the clinical lesion development and associated microbiological changes in CODD affected feet are described over time, resulting in a completely new understanding of the etiopathogenesis of CODD. The majority of CODD lesions (83.9%) arose from pre-existing interdigital dermatitis (ID) and/or footrot (FR) lesions. All stages of foot disease were associated with high levels of poly-bacterial colonization with five pathogens, which were detected by quantitative PCR (qPCR): Treponema medium, Treponema phagedenis, Treponema pedis, Dichelobacter nodosus, and Fusobacterium necrophorum. Temporal colonization patterns showed a trend for early colonization by T. phagedenis, followed by F. necrophorum and D. nodosus, T. medium, and then T. pedis, D. nodosus was present at significantly higher predicted mean log10 genome copy numbers in FR lesions compared to both ID and CODD, while Treponema species were significantly higher in CODD and FR lesions compared to ID lesions (p &lt; 0.001). Treatment of CODD-affected sheep with two doses of 10 mg/kg long acting amoxicillin resulted in a 91.7% clinical cure rate by 3 weeks post-treatment; however, a bacteriological cure was not established for all CODD-affected feet. The study found that in an infected flock, healthy feet, healed CODD feet, and treated CODD feet can be colonized by some or all of the five pathogens associated with CODD and therefore could be a source of continued infection in flocks. The study is an experimental study, and the findings require validation in field CODD cases. However, it does provide a new understanding of the etiopathogenesis of CODD and further supportive evidence for the importance of current advice on the control of CODD; namely, ensuring optimum flock control of footrot and prompt isolation and effective treatment of clinical cases.

Investigating Effects of Metakaolin Content on the Physical Properties of Concrete, and its Susceptibility to Colonization and Biodegradation by Sulphur Oxidizing Bacteria

Biogenic sulphuric acid attack on concrete is a concern worldwide, as it can lead to collapse of sewer infrastructure. Despite knowledge of the cause and the degradation pathways, not much is known about colonization patterns by sulphur oxidizing bacteria. These bacteria were grown on concrete in attempts to catalog degradation and colonization patterns. This was achieved using a battery of concrete property tests and experimenting with imaging techniques. Increased metakaolin content of concrete decreased sorptivity and chloride permeability of concrete while increasing strength and porosity. Concrete with higher metakaolin appeared more resistant to biogenic acid attack, despite increased porosity. Advances were made in protocols for imaging bacteria on a concrete surface, a challenge given the presence of autofluorescing materials in concrete. Information gained has shown that imaging bacteria on an autofluorescent surface can be achieved, and recommendations are made to further advance these efforts.

Investigating Effects of Metakaolin Content on the Physical Properties of Concrete, and its Susceptibility to Colonization and Biodegradation by Sulphur Oxidizing Bacteria

Biogenic sulphuric acid attack on concrete is a concern worldwide, as it can lead to collapse of sewer infrastructure. Despite knowledge of the cause and the degradation pathways, not much is known about colonization patterns by sulphur oxidizing bacteria. These bacteria were grown on concrete in attempts to catalog degradation and colonization patterns. This was achieved using a battery of concrete property tests and experimenting with imaging techniques. Increased metakaolin content of concrete decreased sorptivity and chloride permeability of concrete while increasing strength and porosity. Concrete with higher metakaolin appeared more resistant to biogenic acid attack, despite increased porosity. Advances were made in protocols for imaging bacteria on a concrete surface, a challenge given the presence of autofluorescing materials in concrete. Information gained has shown that imaging bacteria on an autofluorescent surface can be achieved, and recommendations are made to further advance these efforts.