Microbiology ch 22,23,26

List at least 4 arboviral diseases.

1)West Nile fever 2)Easter equine encephalitis 3)Western equine encephalitis 4) St. Louis encephalitis

Know the primary reservoir and mode of transmission, identify the three species that are the most common causes of bacterial meningitis.

1. Haemophilus infleunzae-Reservoir is adult carries, and this organism is part of normal flora and can be transmitted from person to person via aerosols. 2. Neisseria meningitidis-Reservoir is asympromatic carriers. This microbe is usually carried in the nasopharynx. Transmission occurs from person to person via respiratory aerosols. 3. Streptococcus pneumoniae-Commonly found as normal flora of the upper respiratory trace. Has a well developed capsule which is an important virulence factor. This organism is also the most common causative agent of otitis media and is also a major causative agent of bacterial pneumonia.

Identify the causative agents, primary mode of transmission, and characteristic symptoms of the following diseases. Anthrax (differentiate between the cutaneous, gastrointestinal, and pulmonary forms), gas gangrene, plague( differentiate between bubonic and pneumonic plague), Lyme disease, Ricky mountain spotted fever, infectious mononucleosis, yellow fever, dengue fever, toxoplasmosis, malaria.

Anthrax, causative agent is Bacillus anthracis. Anthrax is primarily a disease of grazing animals. Cutaneous anthrax- transmitted by spores entering a broken skin. Growth of the organism in the skin. Gastrointestinal anthrax- food borne (ingestion of spores). Causes nausea, abdominal pain, diarrhea, and ulcerative lesions in the GI tract. Inhalation (pulmonary) anthrax- transmitted via inhalation of spores. The spores germinate an grow In the lungs releasing toxins that produce a wide range of effects that include :capillary thrombosis and cardiovascular shock. This form of anthrax often rapidly progressed into an aggressive, fatal septicemia. Gas gangrene-causative agents is various species of Clostridium particularly Clostridium perfringens. Gas gangrene occurs when spores contaminate sounds that interrupt the blood supply and progression of necrosis into healthy tissue. Gas formed from fermentation of carbohydrates in muscle tissue accumulates in the affected tissue causing it to swell and "bubble up" Plague-causative agent is Yersinia Pestis. The organism is of zoonotic origin. The major reservoir of this organism is mammals, esp rodents. Humans are accidental hosts. The BUBONIC form of this disease is transmitted primarily via flea vector. Transmission occurs when the flea feeds on an infected host then attempts to feed on another host and regurgitate infected blood into the new host. Upon entry into the new host the organism invades the lymph system causing necrosis and swelling of local lymph nodes. These tender swollen nodes are characteristic of the disease and are called buboes. Buboes can occur anywhere but typically appear in the ground and armpit. Other symptoms that may occur are headache fever child nausea and weakness. Bubonic plague often progresses into massive septicemia. This form of the disease is called septicemic plague. This form is characterized by subcutaneous hemorrhagic that may degenerate into necrosis and gangrene. This hemorrhage causes a darkening of the skin (Black Death) . Another form of this disease is PNEUMONIC PLAGUE . In this form the infection is localized in the lungs and is transmitted via sputum and aerosols (no vector is required) this form has a high mortality rate. Lyme disease-causative agent is Borrelia burgdorferi. Transmission is via a tick vector. Initial symptom is characteristic of the disease is a development of a rash at the site of tick bite called erythema migrants or bulls eye rash. The rash is a raised ring that gradually spreads outward from a pale center. Other symptoms include fever headache stiff neck and dizziness. Rocky Mountain fever causative agent is Rickettsia rickettii. Transmission from Host to via a tick vector. Symptoms include fever chills headache and muscle pain. Few days after initial symptom appears a distinctive mascular rash often develops eventually covering the entire body. Infectious mononucleosis is most common in young adults. Symptoms Include sore throat, high fever and swollen cervical lymph nodes. (Flu like) . Some patients develop a gray white exudate in the pharynx, skin rash and enlarged spleen and liver. A characteristic sign of this disease is a sudden leukocytisis, consisting of infected B cells (mononucleosis) Yellow fever. Causative agent is yellow fever virus. Transmitted via a mosquito vector. Has an acute onset of fever, chills, headache, and muscle pain. Some cases disease is more serious and cussed oral hemorrhage, nosebleed, vomiting blood, jaundice, liver and kidney damage and failure. Jaundiced causes have high mortality rate. Dengue fever- causative agent is dengue fever virus and is transmitted by mosquitos. Symptoms are mild fever, severe muscle and joint pain(breakbone fever) in some cases dengue hemorrhagic shock is potentially fatal. Toxoplasmosis causative a grant is Toxoplasma gondii. Principal reservoir and only definitive host of this organism is cats. Transmission- the organism is shed as oocysts in the feces of cats. Humans inquire the disease by ingestion of the oocysts (fecal oral) congenital (transplacental) transmission can also occur. In intermediate hosts the organism becomes encrusted in tissue esp muscle and brain and infection can occur by ingestion of undercooked meat from these animals. Transmission is also possible Via blood exchange. This disease is a systemic infection. Most infections are asymptomatic. Symptomatic infections are typically mild and include fever sore throat lymph node enlargement . Malaria- causative agents- Plasmodium spp. (P. Vivax, P malariiae, P ovale, P falciparum. ) Transmission is primarily via mosquito vector, although transmission can also occur by exchange of blood. Characteristic signs and symptoms are chills, fever, and swearing that occur at regular intervals. These symptoms are the body's response to RBC pigments and waste products from the parasites released when the RBC ruptures.

Identify causative agents, primary mode of transmission, and characterize symptoms of the following diseases. Also note any info in parentheses: gonorrhea, syphilis( differentiate between primary, secondary, latent and tertiary stages) lymphogranuloma, venereum, chancroid, bacterial vaginitis, general herpes, general warts, vulvovaginal candidiasis, trichomoniasis.

Gonorrhea causative agent is Neisseria gonorrhoeae. Transmission is sexual contact. Symptoms are inflammation and purulent(pus containing) discharge. Usually occurs in urethritis (in men) and cervictis, but can spread to other tissues of the genitourinary tract. Scarring often results from infection. Infertility can result from scar tissue blocking the reproductive structures.

Know the major reservoir of Cryptococcus neoformans.

Heavily encapsulated yeast, typically existing in the environment as a soil saprophyte. The organism is often found in areas where pigeon droppings have accumulated. The organism enters the body via inhalation of spores and the disease begins as a lung infection. In some cases the organism enters the bloodstream and travels to other tissues C. neoformans has a particular affinity for the brain and meninges and often presents as a chronic meningitis. Other areas that may be affected are the skin, bones, and viscera.

Identify Streptococcus pneumoniae as a major cause of otitis media.

Identify Streptococcus pneumoniae as a major cause of otitis media.

Identify escherichia coli as the most common causative agent of urinary system disease.

Identify escherichia coli as the most common causative agent of urinary system disease.

List the predisposing factors for severe complications from listeriosis.

In pregnant women it can lead to preterm labor, spontaneous abortion, stillbirth. The organism can also cause sepsis, and can infect the CNS and cause meningitis, encephalitis, meningoencephalitis, and accesses. These types of infections occur primarily in the very young, and people with compromised immunity.

Be familiar with the link between infant botulism and honey consumption.

Infant botulism results when spores are ingested, colonize the gut, and produce the botulinal toxin. The toxin is absorbed and produces the characteristic symptoms of progressive, flaccid paralysis. The immature stage of the gut flora of babies allow the organism to colonize the guy. Honest consumption is associated.

Cystitis

Inflammation of the bladder.

Endocarditis

Inflammation of the inner lining of the heart (endocardium)

Pyelonephritis

Inflammation of the kidney.

Salpingitis

Is a PID affecting the Fallopian tubes. Untreated can lead to scarring and cause sterility or ectopic pregnancy.

Identify causative agent(s), primary mode of transmission, and characteristic/primary symptoms of the following diseases: Listerosis, Tetanus, Botulism( distinguish between foodborne, infant, and wound botulism), Leprosy, Rabies, Cryptococcosis.

Listeriosis- Causative agent is Listeria monocytogenes (gram positive rod), Reservoirs are soil and water. Most cases of listeriosis are associated with ingestion of contaminated food (foodborne) esp dairy products, poultry, and meat. Ingestion leads to infection of intestinal mucosa and it can spread via the bloodstream to other parts of the body, Characteristic symptoms in normal adults listeriosos is typically mild and often sub clinical. Common symptoms include fever, sore throat, and diarrhea. Tetanus-Causative agent is Clostridium tetani, reservoirs is soil. Typical transmission route is entry of spores through a wound, especially puncture wounds. The would neurotoxin called tetanospasmin. This toxin spreads from the infection site to local nerves, eventually reaching the spinal cord. The toxin binds to neurons responsible for inhibiting skeletal muscle contraction. Symptoms of tetanus is uncontrolled muscle contraction (spastic paralysis). These contractions are intermittent and often very powerful. Fatalities may result from respiratory paralysis. Botulism- causative agent is Clostridium botulinum B, reservoir is soil and some aquatic habitats. The organism produces a potent neurotoxin called botulinal toxin. This toxin blocks nerve transmission by preventing release of acetycholine, which in turn, inhibits muscle contraction. The characteristic sing of the disease is a progressive flaccid paralysis. There are multiple forms of the disease.

Identify the most common causative agents of Nongonociccal urethritis and pelvic inflammatory disease.

Most common cause of Nongonociccal urethritis is Chlamydia trachomatis, a common sexually transmitted disease. Most common causative age and of PID is Neisseria gonorrhoeae & chamlydia trachomatis.

Identify the major reservoir of toxoplasmosis parasites and be familiar with the possible complications when a pregnant women is infected.

Principal reservoir and only definitive host of this organism is cats. Immu incompatible individuals can experience serious complications and the disease is of particular concern because of the effects of congenital infection which can result in stillbirth or severe fetal damage.

Know why successful, post-exposure vaccination to rabies is possible.

Rabies progresses so slowly and has such an extended incubation period, it is possible to acquire active immunity before the brain and spinal cord are involved.

Septicemia

Sepsis caused by proliferation of bacteria in the bloodstream.

Septic shock

Shock (sudden loss of blood flow) cause by sepsis.

Know the primary causative agents of Subacute and Acute forms of Endocarditis

Subacute endocarditis- caused primarily by normal flora streptococci. Acute endocarditis- cause primarily by Staphylococcus aureus . Both types can cause serious heart damage and is often fatal if untreated.

Identify the mode of transmission of Arboviruses.

They are a loose grouping of viruses that are all transmitted by arthropod vector.

Sepsis

Toxic inflammatory condition resulting from the spread of microbe or microbial toxins.

Distinguish between the two clinical forms of leprosy.

Two clinical forms are Tuberculoid and Lepromatous. Tuberculoid-superficial form. Characterized by patches of skin with loss of sensation surrounded by a border of small modules. Few bacilli are formed in the lesions. Lepromatous-severe form. Characterized by large, disfiguring nodules that form primarily in the cooler areas of the body. These modules are teeming with bacteria. In this form, growth of the organism causes granulomatous thickening of the face, nose, ears, eyebrows, and chin called lepromas. This results in what is described as a lion faced appearance.