Table 4.
A Summary of Secondary Bacterial Infection mechanisms, responsible for respiratory viral infections and bacterial confections.
| Mechanism | Description | Refs |
|---|---|---|
| -Virus causing increase in Bacterial attachment | -Receptors are modulated by viruses, hence increasing attachment of bacteria. | [158,168] |
| -Cells are destroyed by enzymes from Viruses. | -Glycoproteins are destroyed by enzymes, especially those that are involved in inhibition of bacterial adhesion. | [158] |
| -Muco-ciliary clearance is reduced. | -Decreased muco-ciliary clearance due to virus causes reduced bacterial material production. | [158] |
| -Reduced Chemotaxis | -Chemotactic factor is reduced by virus hence and decreasing response to invading organisms. | [158] |
| -Straight consequence on phagocytic, initiation of functions of alveolar macrophages after phagocytic | -Many functions like fusion of phagosome and lysosome is stopped by virus. | [158] |
| -Undeveloped phagocytes are induced. | -Macrophages are disrupted by viruses and are replaced with undeveloped phagocytes | [158,169,170] |
| -Decrease in surfactant amount | -Alveolar type 2 pneumocytes’ function is impaired by viruses. | [158,171,172] |
| -Dysbiosis is introduced in microbiome of lower respiratory-tract. | -Immune-response towards respiratory viral-infections is affected by dysbiosis in microbiome. | [173] |
| -Innate and adaptive immunity is dysregulated. | -During the development of apoptosis alverolar macrophages are decreased in number by virus. | [[174], [175], [176], [177]] |
| -Inflammation and apoptosis are modulated. | -Post viral infection secondary-bacterial pneumonia is facilitated by apoptosis and autophagy. | [178] |
| -Immune function of antibacterial is reduced at respiratory-epithelium. | -Viral infections of respiratory-tract causes inclination to secondary bacterial-infection by deviating immune status of respiratory tract. | [158,179,180] |
| -Nutritional immunity is disturbed. | -Some viral infections destabilize nutritional shield and enhance bacterial invasion. | [[181], [182], [183]] |
| -Suppression of immune system | -Some viruses like HIV induce immunosuppression. | [[184], [185], [186]] |
| -Synergistic viral and bacterial co infections | -Co infection’s immuno-pathogenicity is regulated by bacteria as well as viruses. | [159,171,187] |
| -Planktonic bacteria released from biofilms | -Biofilm structure is disrupted by manipulation of many factors like H2O2 and chemokines due to viruses. | [177,[188], [189], [190]] |