Carbuncles - are a series of interconnected furuncles with more extensive tissue invasion
Septicemia – from carbuncles the organism may spread to the bloodstream to cause septicemia
Staph. aureus may also cause impetigo (see Strep. skin infections), mainly in newborns
Skin conditions due to toxin production:
Scalded skin syndrome – this condition occurs when the organism produces an exotoxin called the exfoliative or epidermolytic toxin . The toxin causes the outer skin to peel away in layers.
Toxic shock syndrome – exfoliation of the skin may also occur in cases of toxic shock syndrome involving tampon use in menstruating women. This is due to the effects of toxic shock syndrome toxin, type I.
The organism is not invasive , but it attaches to respiratory epithelia, impeding their action. This causes a build-up of mucous.
The disease occurs in 3 stages
Catarrhal stage - symptoms similar to the common cold
Paroxysmal stage – characterized by prolonged sieges of coughing as the patient tries to get rid of the mucous that has built up. Gasping of air occurs between the coughs causing a whooping sound. Lasts 1-6 weeks
After a few weeks many of the macrophages die, releasing tubercle bacilli and forming a caseous center inside the tubercle. In healthy individuals, the disease is usually arrested at this time and the lesions may may become calcified. Tubercle bacilli may remain dormant in the lesion and serve as a basis for later reactivation of the disease.
When the defenses fail, a mature tubercle may form and then the bacilli multiply.
The tubercle eventually ruptures, releasing tubercle bacilli that can disseminate throughout the body.
This is the progressive form of the disease and symptoms include weight loss, coughing with blood, and loss of vigor.
Spores are found in feces, soil, and dust. Spores enter the body through penetrating wounds where they germinate into vegetative cells and subsequently produce toxin
Symptoms begin with cramps and twitching of muscles around the wound. Headache and neck stiffness also occur. These are followed by trismus (lockjaw ) and more generalized symptoms. Death, if it occurs, results from respiratory failure
Septicemia – a condition in which bacteria are actively multiplying and/or releasing toxins into the blood. One symptom of this is lymphangitis where red streaks are seen in the skin radiating out from the initial site of infection
Caused by Yersinia pestis which is endemic in the mountains in Southern California
There are two forms of the disease – bubonic plaque and pneumonic plague
Bubonic plague is transmitted by rat fleas
The organism gets into the bloodstream and makes its way to the regional lymph nodes which become painful and enlarged (called buboes and hence the name bubonic plaque). The mortality rate in untreated cases is high.
When the organism gets into the lungs it can cause pneumonic plague which is transmitted from person to person via droplet infection . Has a higher mortality rate than bubonic plague (close to 100%)
Two basic types of disease may occur in the lower intestinal tract;
Infection in which the organism attaches, invades, and multiplies.
There is a delay in the appearance of symptoms as the organism multiplies.
Symptoms include fever , diarrhea (dysentery may occur), nausea and possibly, vomiting.
Organisms that may cause infection are Salmonella species , including Salmonella typhi which causes typhoid fever, Shigella species, Vibrio parahaemolyticus, Campylobacter jejuni , and certain strains of E. coli.
Intoxication – here disease is due to the ingestion of a preformed toxin or to a toxin produced by an organism which is not invasive, but multiplies at the intestinal mucosa while liberating toxin.
Uncomplicated infections in females - may have increased vaginal discharge, burning or frequency of urination and menstrual abnormalities.
Occur more frequently in women - spread from the cervix into the fallopian tubes resulting in endometritis, salpingitis, and peritonitis= pelvic inflammatory disease (PID). Occurs in 10-20% of infected women. Symptoms include lower abdominal pain, abnormal vaginal and cervical discharge, and uterine tenderness. This can result in ectopic pregnancy and infertility.
Nongonococcal urethritis – caused by Chlamydia trachomatis with symptoms as above