s vs pathogenic bacteria in
COPD Each species has specific effect and causes symptoms in people who are infected. Some people who are infected with a pathogenic bacteria do not have symptoms. Immunocompromised individuals are more susceptible to pathogenic bacteria.
Pathogenic susceptibility Some pathogenic bacteria cause disease under certain conditions, such as entry through the skin via a cut, through sexual activity or through compromised immune function. Some species of
Streptococcus and
Staphylococcus are part of the normal
skin microbiota and typically reside on healthy skin or in the nasopharyngeal region. Yet these species can potentially initiate skin infections.
Streptococcal infections include
sepsis,
pneumonia, and
meningitis. These infections can become serious creating a systemic inflammatory response resulting in massive vasodilation, shock, and death. Other bacteria are
opportunistic pathogens and cause disease mainly in people with
immunosuppression or
cystic fibrosis. Examples of these opportunistic pathogens include
Pseudomonas aeruginosa,
Burkholderia cenocepacia, and
Mycobacterium avium.
Intracellular Obligate intracellular parasites (e.g.
Chlamydophila,
Ehrlichia,
Rickettsia) are only able to grow and replicate inside other cells. Infections due to obligate intracellular bacteria may be
asymptomatic, requiring an
incubation period. Examples of obligate intracellular bacteria include
Rickettsia prowazekii (
typhus) and
Rickettsia rickettsii, (
Rocky Mountain spotted fever).
Chlamydia are intracellular parasites. These pathogens can cause
pneumonia or
urinary tract infection and may be involved in
coronary heart disease. Other groups of intracellular bacterial pathogens include
Salmonella,
Neisseria,
Brucella,
Mycobacterium,
Nocardia, Listeria,
Francisella,
Legionella, and
Yersinia pestis. These can exist intracellularly, but can exist outside host cells.
Infections in specific tissue Bacterial pathogens often cause infection in specific areas of the body. Others are generalists. •
Bacterial vaginosis is a condition of the
vaginal microbiota in which an excessive growth of
Gardnerella vaginalis and other mostly
anaerobic bacteria displace the beneficial
Lactobacilli species that maintain healthy vaginal microbial populations. •
Bacterial meningitis is a bacterial
inflammation of the
meninges, which are the protective membranes covering the
brain and
spinal cord. •
Bacterial pneumonia is a bacterial infection of the
lungs. •
Urinary tract infection is predominantly caused by bacteria. Symptoms include the strong and frequent sensation or urge to urinate, pain during
urination, and urine that is cloudy. The most frequent cause is
Escherichia coli.
Urine is typically sterile but contains a variety of salts and waste products. Bacteria can ascend into the
bladder or
kidney and causing
cystitis and
nephritis. •
Bacterial gastroenteritis is caused by enteric, pathogenic bacteria. These pathogenic species are usually distinct from the usually harmless bacteria of the normal
gut flora. But a different strain of the same species may be pathogenic. The distinction is sometimes difficult as in the case of
Escherichia. • Bacterial
skin infections include: •
Impetigo is a highly contagious
bacterial
skin infection commonly seen in children. It is caused by
Staphylococcus aureus, and
Streptococcus pyogenes. •
Erysipelas is an acute
streptococcus bacterial infection of the deeper skin layers that spreads via with lymphatic system. •
Cellulitis is a diffuse
inflammation of
connective tissue with severe inflammation of dermal and subcutaneous layers of the
skin. Cellulitis can be caused by normal
skin flora or by
contagious contact, and usually occurs through open skin, cuts,
blisters, cracks in the skin,
insect bites,
animal bites,
burns,
surgical wounds, intravenous
drug injection, or sites of
intravenous catheter insertion. In most cases it is the skin on the face or lower legs that is affected, though cellulitis can occur in other tissues. ==Mechanisms of damage==