Resident aerobic microbiota of the adult human nasal cavity

Abstract

Recent evidence strongly suggests that the microbiota of the nasal cavity plays a crucial role in determining the reaction patterns of the mucosal and systemic immune system. However, little is known about the normal microbiota of the nasal cavity. The purpose of this study was to determine the microbiota in different parts of the nasal cavity and to develop and evaluate methods for this purpose. Samples were collected from 10 healthy adults by nasal washes and by swabbing of the mucosa through a sterile introduction device. Both methods gave results that were quantitatively and qualitatively reproducible, and revealed significant differences in the density of the nasal microbiota between individuals. The study revealed absence of gram-negative bacteria that are regular members of the commensal microbiota of the pharynx. Likewise, viridans type streptococci were sparsely represented. The nasal microbiota was dominated by species of the genera Corynebacterium, Aureobacterium, Rhodococcus, and Staphylococcus, including S. epidermis, S. capitis, S. hominis, S. haemolyticus, S. lugdunensis and S. warneri. These studies show that the microbiota of the nasal cavity of adults is strikingly different from that of the pharynx, and that the nasal cavity is a primary habitat for several species of diphtheroids recognized as opportunistic pathogens. Under special circumstances, single species, including IgA1 protease-producing bacteria, may become predominant in a restricted area of the nasal mucosa.

Role of Microbes in Human Health

“…On the other hand, species of Corynebacterium, Aureobacterium, Rhodococcus and Staphylococcus have been found to be present dominantly. These data suggested that microbiota present in the nasal cavity of adult humans are strikingly different from that of the pharynx [6].…”

Bacteriocin-like inhibitory substance (BLIS) production by the normal flora of the nasopharynx: potential to protect against otitis media?

“…Could this perhaps indicate that S. salivarius strains producing both salivaricin A and salivaricin B are particularly well adapted to growth in the nasopharynx? Although S. salivarius is not usually considered to be a predominant member of the nasopharyngeal flora of adults (Rasmussen et al, 2000), in children under the age of 2 it is the second-most-frequently isolated streptococcal species at this site after S. mitis 1 (Könönen et al, 2002). Since S. salivarius is considered to be essentially nonpathogenic, it could be an excellent candidate for possible introduction into the normal nasopharyngeal flora as protection against recurrent AOM.…”

A comparative study on detecting bacterial flora of the nasal cavity in normal healthy workers that work in cement factory and the healthy Students in Koya University

“…Thirty five workers attending the research were in cement factory, thirteen of the workers were found that they have Candida albican as show in table (2).…”

“…Citrobacter is a genus of Gram-negative coliform bacteria in the Enterobacteriaceae family [25]. In this study one strain of Citrobacter freundii isolated from worker's nose cavity (2.85%) as shown in table (2).…”

“…However, little is known about the normal microbiota of the nasal cavity. [2] Bioaerosol concentrations at 50m upwind of site operations were within a range considered to be ‗typical' background levels, with the large majority (84 %+) of samples yielding less than 1,000 cfu/m 3 air of bacteria, actinomycetes, fungi and Aspergillus fumigatus. Close to compost handling activities, if workers are not protected from exposure, they may be exposed to concentrations of airborne bacteria and fungi that frequently exceed [3].…”