Chapter 23 Microbial Diseases of the Cardiovascular and Lymphatic Systems
The Cardiovascular System Figure 23.1
The Lymphatic System Figure 23.2
The Cardiovascular System and Lymphatics System Blood —Transports nutrients to and wastes from cells White blood Cells —Defend against infection Lymphatics —Transport interstitial fluid to blood Interstitial fluid (lymph) is blood plasma that has filtered out of the capillaries into spaces between tissue cells (interstitial spaces)
Lymph nodes —Contain macrophages that clear pathogens from the lymph
Bacteria growing in the blood Fever, chills, increased heart rate and breathing Results in drop in blood pressure , affects organs Sepsis and Septic Shock
Low blood pressure cannot be controlled by addition of fluid
Endotoxins caused blood pressure decrease Antibiotics can worsen condition by killing bacteria Puerperal Sepsis (Childbirth fever) Sepsis
Transmitted to mother during childbirth by attending physicians & midwives
Brucellosis Direct contact, milk products. Infects uterus- mesoerythritol requirement. ( a carbohydrate produced in the fetus ) Chills, fever, malaise, heavy sweating. Undulating - fever rises in evening 104˚C. Animals secrete bacteria in milk. Pasteurization process tailored for this pathogen. Organism survives phagocytosis, grows intracellularly.
R x ~ tetracycline + streptomycin -long treatment.
Gas Gangrene Produces toxins that travel down muscle bundles. Many proteolytic enzymes, hyaluronidase, collagenase, lipases. P. aeruginosa can co-infect. Treatment - remove necrotic tissue, amputation, surgical maggots.
Hyperbaric O 2 - internal tissues
Gas Gangrene Gram + rod, anaerobe (not strict), sporeformer. Ischemia -lack of blood supply. Gangrene -death of soft tissue.
Diabetes, injury, cancer.
Bacterial Infections of the Heart Inflammation of the endocardium ( inner heart muscle lining) Rapid destruction of the heart valves leads to death
Can be caused by Stapylococcus aureus and Streptococci
Rheumatic Fever Repeated infections with S. pyogenes -strep throat. Streptococal antigens (M protein) cross react with heart antigens. Antibody response to kill organisms damages heart.
Initial signs, arthritis and fever followed by nodes
Anthrax Bacillus anthraci s, gram-positive, endospore-forming aerobic rod, found in soil Endospores enter through minor cut, 20% mortality Skin infection begins as a raised itchy bump that resembles an insect bite. Has a necrotic area in the center. Ingestion of undercooked food contaminated food, 50% mortality
Inhalation of endospores,
Inhalation Anthrax cont. Initial symptoms may resemble a common cold – sore throat, mild fever, muscle aches and malaise. After several days, the symptoms may progress to severe breathing problems and shock. Pulmonary form most serious, enters lungs then to bloodstream, leads to septicemia; usually fatal. Pathogenic factors include: Anti-phagocytic capsule (poly- D -glutamic acid) PA- protective antigen - binding factor
R x ~ penicillin, docycycline; ciprofloxacin.
What Disease ? 1 rosy red rash in the shape of a ring on the skin- flea bite. 2 Pockets and pouches were filled with sweet smelling herbs ( or posies) which were carried due to the belief that the disease was transmitted by bad smells. 3 The term "Ashes Ashes" refers to the cremation of the dead bodies!
"Ashes, Ashes" 3
Vector Borne Diseases - Plague Zoonoses, disease of rodents (squirrels, prairie dogs) spread by rat flea.
14 -15th Centuries killed 1/4 th to 1/3 rd of entire European population.
Vector Borne Diseases - Plague 9.5 kb plasmid that codes for a plasminogen activator that is necessary for systemic spread. Organism enters blood via bite and can grow in phagocytes. R x ~ streptomycin, tetracycline .
Another plasmid that codes for an anti-phagocytic capsule.
Vector Borne Diseases - Plague Fever, chills, headache, then vomiting and nausea. Ysernia pestis Septicemia causes septic shock. Death occurs in a week. 50-75% Mortality if untreated. Some cases can go pneumonic form of the disease -death can occur in 15 -24 hours. Only pneumonic form can be spread person to person. Pneumonic form produces a blood tainted sputum.
6-8 days later bubos form in lymph glands,
Relapsing Fever Borrelia recurrensis or hermsii Spirochete - no Gram reaction. Fever, jaundice, rose-colored skin spots.
Fever breaks after 3-4 days and patient appears to recover.
Relapsing Fever Borrelia recurrensis or hermsii
Fever reappears due to surface antigens changing.
Lyme’s Disease Spirochete - no Gram reaction. Organisms infects tick salivary glands. 10,000 cases annually -most prevalent ABD.
Rodents reservoir. Deer in life cycle of tick.
Lyme’s Disease Bull’s -eye rash -erythema migrans around bite. Flu-like symptoms follow.
Later stages similar to syphilis - heart and neurological involvement.
Chapter 24 Microbial Diseases of the Respiratory System
Breathing It starts at the nose. About 20 times a minute. When you do, you inhale air and pass it through your nasal passages where the air is filtered, heated, moistened and enters the back of the throat. Interestingly enough, it's the esophagus or food pipe which is located at the back of the throat and the windpipe for air which is located at the front.
When we eat, a flap -- the epiglottis -- flaps down to cover the windpipe so that food doesn't go down the windpipe.
what happens to the carbon dioxide? It goes through the lungs, back up your windpipe and out with every exhale. It's a remarkable feat, this chemical exchange and breathing in and out.
You don't have to tell your lungs to keep working. Your brain does it automatically for you.
Factoids Your lungs contain almost 1500 miles of airways and over 300 million alveoli. Every minute you breathe in 13 pints of air. Plants are our partners in breathing. We breathe in air, use the oxygen in it, and release carbon dioxide. Plants take in carbon dioxide and release oxygen. People tend to get more colds in the winter because we're indoors more often and in close proximity to other people.
When people sneeze, cough and even breathe -- germs go flying
Upper Respiratory System Figure 24.1
Upper respiratory normal microbiota may include pathogens
Microbial Diseases of the Upper Respiratory System Infection of the larynx, affects speaking ability Mucous membranes become inflammed
Inflammation of the epiglottis, most dangerous
Steptococcal Pharyngitis -hemolytic, M protein makes resistant to phagocytosis. Streptokinase, streptolysin. Culture from throat swab. Local infection, sore throat, fever.
Can progress to otidis media.
Scarlet Fever Invades upper respiratory tract. Erythrogenic toxin produces small “goose bumps” on skin - spreads over entire body except face, palms, and soles to make red rash.
High fever, chills, nausea, vomiting, abdominal pain, and malaise.
While the rash is still red, the patient may develop Pastia's lines, bright red coloration of the creases under the arm and in the groin.
Diphtheria Corynebacterium diphtheriae Club shaped, chinese characters.
Produces potent toxin that inhibits protein synthesis.
Diphtheria Corynebacterium diphtheriae Produces pseudomembrane on back of throat. Diphtheria means “leather” for the texture of the pseudomembrane. Produces potent toxin that inhibits protein synthesis. First developed by Von Behring* in 1890. R x ~ penicillin, erythromycin.
Vaccine DTaP -2, 4, 6 months.
Otidis media Eustacian tube “S-shaped”.
R x ~ amoxicillin, sulfa drugs.
Lower Respiratory System
Is nearly sterile, does not typically have normal microbiota
Microbial Diseases of the Lower Respiratory System
Bacteria, viruses, & fungi cause:
Pertussis (Whooping cough) Gram - obligate aerobe, capsulated, coccobacillus. Whoop comes from sound of patient gasping for air between coughs. Vaccination -DPT has reduced number from 250,000 to 7000. Mainly a childhood disease
Violent coughing, can result in broken ribs in children
Tuberculosis (consumption) Mycobacterium tuberculosis Acid -fast rod, in filaments (myco -fungus). Enters lung, reaches alveoli. Macrophages wall off into a tubercle in healthy people.
When immune system weakens or fails they can reinfect lungs.
Tuberculosis Symptoms include coughing, rusty (blood) sputum, weight loss. Tuberculin indicates exposure , not necessarily active disease.
R x ~ isoniazid, rifampicin, streptomycin.
Bacterial pneumonias Gram + diplococcus, capsulated. Infects bronchi and alveoli. High fever, difficulty breathing, chest pains.
Sometimes progresses to septicemia and meningitis.
Bacterial pneumonias Atypical “walking” pneumoniae Low grade fever, headache, cough Colonies “fried egg”appearance.
Associated w atherosclerosis
Legionaires Disease Gram - rod, aerobic, non-sporeformer. Occurs in nature, water. Resistant to chlorine.
High fever, other symptoms of pneumonia.
Tuberculosis Mycobacterium tuberculosis : Acid-fast rod. Transmitted from human to human Treatment by prolonged use of multiple antibiotics
Major problem in treating due to lack of patient compliance
Pneumonia Streptococcus pneumoniae : Gram-positive with capsule Diagnosis by culturing bacteria Penicillin is drug of choice Haemophilus influenzae Pneumoniae
Alcoholism, poor nutrition, cancer, or diabetes are predisposing factors