At least 12 Opa proteins are known and the many permutations of surface proteins make recognizing N. gonorrhoeae and mounting a defense by immune cells more difficult.Lipooligosaccharide (LOS) is a low-weight version of lipopolysaccharide present on the surfaces of most other Gram-negative bacteria. It is a sugar (saccharide) side chain attached to lipid A (thus "lipo-") in the outer membrane coating the cell wall of the bacteria. The root "oligo" refers to the fact that it is a few sugars shorter than the typical lipopolysaccharide. As an endotoxin, LOS provokes inflammation. The shedding of LOS by the bacteria is responsible for local injury in, for example, pelvic inflammatory disease. Although its main function is as an endotoxin, LOS may disguise itself with host sialic acid and block initiation of the complement cascade. Antigenic variation
N. gonorrhoeae evades the immune system through a process called antigenic variation. This process allows N. gonorrhoeae to recombine its genes and alter the antigenic determinants (sites where antibodies bind), such as the Type IV pili, that adorn its surface. Simply stated, the chemical composition of molecules is changed due to changes at the genetic level. N. gonorrhoeae is able to vary the composition of its pili, and LOS; of these, the pili exhibit the most antigenic variation due to chromosomal rearrangement. The PilS gene is an example of this ability to rearrange as its combination with the PilE gene is estimated to produce over 100 variants of the PilE protein.
Local damage to the tracheal wall that can be caused by mechanical ventilation is a risk factor for this. Respiratory failure may develop from this infection.Herpetic tracheobronchitis is caused by herpes simplex virus and causes small ulcers covered in exudate to form on the mucous membranes. The exudate contains necrotic cells from the mucosal epithelium. The characteristic increased sputum produced can give problems in the removal of the tracheal tube (extubation). In the course of cystic fibrosis the lungs are affected. Thickened mucus secretions block the airways making infection possible. The recurrence of tracheobronchitis presents a major problem.In chronic obstructive pulmonary disease tracheobronchial infections are responsible for up to 80% of exacerbations. In dogs
Tracheobronchitis often affects dogs particularly those confined in kennels where their persistent barking worsens the inflammation. This canine infectious tracheobronchitis is more usually known as kennel cough. == References ==