What is commensal respiratory flora?

Commensal bacteria act on the host’s immune system to induce protective responses that prevent colonization and invasion by pathogens. On the other hand, these bacteria can directly inhibit the growth of respiratory pathogens by producing antimicrobial products/signals and competing for nutrients and adhesion sites.

Which bacteria is commonly found as commensal in the upper respiratory tract particularly in children?

The URT microbiome is composed of several ‘core’ genera present in the majority of healthy individuals, the most abundant of which include Staphylococcus, Streptococcus, Corynebacterium, Prevotella, Veillonella, Propionibacterium, and Fusobacterium in adults with Moraxella also prominent in young children [17,18,19••.

Where is normal flora found in the respiratory system?

Oral and Upper Respiratory Tract Flora A varied microbial flora is found in the oral cavity, and streptococcal anaerobes inhabit the gingival crevice. The pharynx can be a point of entry and initial colonization for Neisseria, Bordetella, Corynebacterium, and Streptococcus spp.

What is normal flora commensal bacteria?

Commensal microflora (normal microflora, indigenous microbiota) consists of those micro-organisms, which are present on body surfaces covered by epithelial cells and are exposed to the external environment (gastrointestinal and respiratory tract, vagina, skin, etc.).

What is commensal organism?

A commensal is an organism that uses food supplied in the internal or the external environment of the host, without establishing a close association with the host, for instance by feeding on its tissues.

What microorganisms could be found in the upper respiratory tract?

The upper respiratory tract microbiome of infants Moraxella, Staphylococcus, Streptococcus, Haemophilus, Dolosigranulum, and Corynebacterium are the six most common genera, of which one or two usually dominate the nares and nasopharyngeal microbiome of infants [11, 90, 91].

What are some pathogenic bacteria that are part of the normal microbiota of the respiratory tract?

Normal Microbiota of the Respiratory System The most common bacteria identified include Staphylococcus epidermidis, viridans group streptococci (VGS), Corynebacterium spp. (diphtheroids), Propionibacterium spp., and Haemophilus spp.

What are the parts of upper respiratory tract?

The major passages and structures of the upper respiratory tract include the nose or nostrils, nasal cavity, mouth, throat (pharynx), and voice box (larynx). The respiratory system is lined with a mucous membrane that secretes mucus.

What is the border between upper and lower respiratory tract?

The epiglottis separates the upper and lower respiratory tract.

What is a common commensal?

Yeasts in the genera Candida, Malassezia, and Trichosporon are the best known of those commensals (Rippon 1988). Those yeasts are essentially saprobic but are resistant to clearance by the immune system in certain body sites.

What are common commensal organisms?