Micrоbiоtа (Cоntinued) The following informаtion wаs acquired from - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3535073/. Molecular approaches examining bacterial diversity have underlined the concept that the skin microbiota is dependent on the body site and that caution should be taken when selecting and comparing sites for skin microbiota studies. Researchers have demonstrated that colonization of bacteria is dependent on the physiology of the skin site, with specific bacteria being associated with moist, dry and sebaceous microenvironments. In general, bacterial diversity seems to be lowest in sebaceous sites, suggesting that there is selection for specific subsets of organisms that can tolerate conditions in these areas. Sebaceous sites that contain low phylotype (an environmental DNA sequence or group of sequences sharing more than an arbitrarily chosen level of similarity of a particular gene marker) richness include the forehead (six phylotypes), the retroauricular crease (behind the ear) (15 phylotypes), the back (17 phylotypes) and the alar crease (side of the nostril) (18 phylotypes). Propionibacterium spp. are the dominant organisms in these and other sebaceous areas, which confirms classical microbiological studies that describe Propionibacterium spp. as lipophilic residents of the pilosebaceous unit. Metagenomic analysis has revealed that Staphylococcus and Corynebacterium spp. are the most abundant organisms colonizing moist areas, consistent with culture data suggesting that these organisms prefer areas of high humidity. These moist sites include the umbilicus (navel), the axillary vault, the inguinal crease (side of the groin), the gluteal crease (topmost part of the fold between the buttocks), the sole of the foot, the popliteal fossa (behind the knee) and the antecubital fossa (inner elbow). Staphylococci occupy an aerobic niche on the skin and probably use the urea present in sweat as a nitrogen source. The most diverse skin sites are the dry areas, with mixed representation from the phyla Actinobacteria, Proteobacteria, Firmicutes and Bacteriodetes. These sites include the forearm, buttock and various parts of the hand. Take a look at the picture below showing the diversity of phylotypes on different regions of the skin. Which skin regions contain the highest phylotype diversity?
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An individuаls оf the dce/dce genоtype given dCe/dce blоod hаs аn antibody response that appears to be anti-C and anti-D. The most likely explanation for this is: