Micbio

The physical factors include:

1. Skin: the keratinized epidermis forms an intact physical barrier that prevents microbial penetration.
2. Mucous membranes: mucus traps microbes; cilia sweep trapped particles toward the throat to be swallowed or expelled; tears and saliva wash away microbes; urine flushes the urethra; vaginal secretions help remove microbes.

Initial symptoms of rabies include muscle spasms of the mouth and pharynx, as well as hydrophobia (fear of water).

The average incubation period for rabies is 30 to 50 days.

The two forms of rabies are:

Rabies is diagnosed from bodily fluids using the direct fluorescent-antibody (DFA) test.

Postexposure prophylaxis (PEP) for rabies includes:

• Vaccine: Human diploid cell vaccine (HDCV)
• Immune globulin: Human rabies immune globulin (RIG)

The chemical factors include:

1. Sebum (from sebaceous glands): oily film with unsaturated fatty acids that inhibit bacteria and fungi.
2. Perspiration (sweat): flushes microbes and contains lysozyme, an enzyme that degrades bacterial cell walls.
3. Mucus and associated antimicrobial proteins: lysozyme, lactoferrin, and lactoperoxidase.
4. Other secretions (see related pages): saliva (contains lysozyme and IgA), gastric juice (HCl and enzymes, highly acidic), and vaginal secretions (lactic acid from Lactobacillus creating acidic pH).

The steps of phagocytosis include:

1. Chemotaxis — phagocytes are attracted to the site by chemokines and other chemical signals.
2. Adherence (attachment) — recognition and binding to the microbe; opsonization enhances attachment.
3. Ingestion — extension of pseudopodia around the microbe to form a phagosome.
4. Fusion — the phagosome fuses with a lysosome to form a phagolysosome.
5. Digestion — microbial killing and enzymatic digestion.
6. Exocytosis — release of indigestible debris.

• Chloroquine is the preferred treatment for any parasite that is sensitive to the drug.

• ACTs are used for treating chloroquine-resistant malaria. They combine two or more drugs that work against the malaria parasite in different ways.

• Artemether-lumefantrine (Coartem)
• Artesunate-mefloquine (複方蒿甲醚)

• Atovaquone-proguanil (Malarone)
• Quinine sulfate (Qualaquin) with doxycycline
• Primaquine phosphate

• Use of bed nets (蚊帳) to prevent mosquito bites.

• Tetanus is caused by Clostridium tetani.

Tetanospasmin blocks the relaxation pathway in muscles, leading to muscle spasms.

Vaccination with tetanus toxoid stimulates antibodies that neutralize the toxin, providing immunity against tetanus.

Treatment options for tetanus include antitoxin therapy to target unbound toxins, sedatives to control muscle spasms, and vaccination with tetanus toxoid.

Botulism is caused by Clostridium botulinum, which releases a toxin that blocks the release of acetylcholine at the synaptic end of the nerve, resulting in flaccid paralysis.

Antitoxin is used to prevent the botulinal toxin from causing further harm, but it does not heal the damage already done by the toxin.

The mortality rate for tetanus is about 50% in developing areas and about 25% in the United States.

Treatment for wound botulism may include local antibiotics such as penicillin G or metronidazole to eradicate Clostridium botulinum, but aminoglycosides should be avoided as they can worsen muscle weakness.

Leprosy, also known as Hansen's disease, is caused by Mycobacterium leprae, which is an acid-fast rod that grows best at 30°C. It has a generation time of 12 days and primarily grows in peripheral nerves and skin cells. It survives macrophages and invades the myelin sheath.

Leprosy transmission requires prolonged contact with an infected person or the inhalation of secretions from an infected individual.

Initial symptoms of poliomyelitis include sore throat and nausea. Viremia may occur, allowing the virus to enter the CNS. In about 1% of cases, it can become paralytic, leading to the destruction of motor cells and potentially resulting in death from respiratory failure. Additionally, postpolio syndrome can cause muscle weakness decades after infection.

Rabies is caused by the rabies virus, which belongs to the genus Lyssavirus and has a bullet shape. It is a single-stranded RNA virus that can easily develop mutants. The virus is usually transmitted through the saliva of an animal bite and can also cross mucous membranes.

Once a rabies infection is established, there is no effective treatment. The disease usually causes death, so it is crucial to get a series of shots to prevent the infection if exposed.

If bitten by an animal suspected to have rabies, you should receive:

• A fast-acting shot (rabies immune globulin) to prevent the virus from infecting you, given near the bite area as soon as possible.
• A series of rabies vaccinations: Four injections over 14 days if you haven't had the rabies vaccine before, or two injections over the first three days if you have had the vaccine.

Prions are abnormally folded proteins that cause normal proteins in the brain tissue to also become abnormally folded, leading to spongiform degeneration. This condition is chronic and fatal and is associated with transmissible spongiform encephalopathies (TSE) such as sheep scrapie.

The virulence of uropathogens is determined by their ability to:

1. Adhere to the host
2. Avoid host defense mechanisms
3. Show resistance to antimicrobial drugs

Cystitis is the inflammation of the bladder and is the most common site of urinary tract infections (UTIs). It is usually mild and uncomplicated. Common causes include:

• Occurrence alone or with pyelonephritis, prostatitis, or kidney stones
• More common in women due to a short and straight urethra and proximity to the vagina and anus, increasing bacterial contamination
• In adult males, incomplete bladder emptying and urinary stasis due to benign prostatic hyperplasia (BPH) can contribute to UTI development.

The modes of spread of infection in urinary tract infections include:

1. Ascending infection: The most common route, ascending from the urethra to the bladder and then to the kidneys.
2. Haematogenous infection: Spread via the bloodstream.

A sign is a manifestation of disease that the physician perceives, while symptoms represent the complaints of the patient.

The causative agent of Gonorrhea is Neisseria gonorrhoeae, which is a Gram-negative bacterium.

In men, symptoms include painful urination and discharge of pus. In women, symptoms are often few but may lead to complications such as Pelvic Inflammatory Disease (PID).

If left untreated, Gonorrhea may result in endocarditis, meningitis, arthritis, and ophthalmia neonatorum.

The causative agents of Nongonococcal Urethritis include Chlamydia trachomatis, Mycoplasma hominis, and Ureaplasma urealyticum.

Symptoms of Nongonococcal Urethritis include painful urination and watery discharge. In women, there may be possible complications.

Pelvic Inflammatory Disease (PID) is a collective term for any extensive bacterial infection of the female pelvic organs, including the uterus, cervix, uterine tubes, and ovaries.

The symptoms of PID include:

• Chronic abdominal pain
• Possible infertility

PID is diagnosed based on signs and symptoms in association with gonorrheal or chlamydial infections.

The treatment for PID includes:

• Doxycycline taken twice a day for 7 days
• Azithromycin taken just once as a single dose

The causative agent of Syphilis is Treponema pallidum, which produces lipoproteins that induce an inflammatory immune response.

1. Primary Stage: Chancre (sore) at the site of infection, painless, highly infectious fluid.
2. Secondary Stage: Skin and mucosal rashes, especially on palms and soles, lesions contain spirochetes, very infectious.
3. Latent Period: No symptoms.
4. Tertiary Stage: Severe lesions, damage to cardiovascular and nervous system, gumma on organs, congenital syphilis can lead to fetal death or birth defects.

The preferred treatment for syphilis at all stages is a single injection of penicillin. If there is a penicillin allergy, another antibiotic or penicillin desensitization is recommended. Additional doses may be required for syphilis lasting more than 1 year.

The symptoms of genital warts caused by human papillomaviruses (HPV) include warts in the genital area. These warts are transmitted sexually.

Direct Diagnosis: Staining with fluorescent-labeled monoclonal antibodies.

Indirect, Rapid Screening: VDRL (slide agglutination test), RPR (rapid plasma reagin test), EIA (enzyme immunoassay).

Treatment options include:

1. Podofilox cream
2. Imiquimod (Aldara, Zyclara) cream
3. Sinecatechins (Veregen) cream
4. Trichloroacetic acid to burn off genital warts

The first step in the HIV replication cycle is Binding, where HIV binds to molecules on the host CD4 cell surface.

Preventive measures against HIV transmission include:

1. Use condoms properly during each sexual contact
2. Maintain a mutually monogamous relationship with an uninfected partner
3. Avoid sharing needles
4. Pre-exposure prophylaxis (PrEP)
5. Early treatment

Reverse transcriptase is an enzyme used by HIV to convert its RNA into DNA during the Reverse transcription step of the HIV life cycle.

HIV integrates into the host cell's genetic material during the Integration step, where it uses its integrase enzyme to insert its viral DNA into the host DNA.

1. Contact with blood, semen, pre-seminal fluid, vaginal fluids, and rectal fluids.
2. Breast milk.
3. Transplacental infection of the fetus.
4. Blood-contaminated needles.

1. Antibody tests: Rapid HIV tests, enzyme immunoassays (EIA or ELISAs).
2. Viral identification assays: HIV-1 DNA PCR, Plasma HIV RNA assays.

HIV medicines prevent the virus from multiplying, reducing the viral load in the body. This allows the immune system to recover and produce more CD4 cells, enabling it to fight off infections and certain HIV-related cancers, despite the presence of some HIV in the body.

1. Viral load test.
2. CD4 count test.
3. Drug resistance test.

HAART stands for Highly Active Anti-Retroviral Therapy, which is a treatment regimen for HIV that combines multiple antiretroviral medications to effectively manage the virus.

Symptoms: Painful vesicles in the genital area.

Treatment: Acyclovir.

Pathogen: Human papillomaviruses (HPV).

Treatment Options: Podofilox, imiquimod, and preventive vaccine.

Symptoms: Pathogenic infections, malignancies, low CD4 count.

Treatment: Prophylaxis for opportunistic infections.

Symptoms: Severe vaginal itching, yeasty odor, yellow discharge.

Treatment: Clotrimazole, Fluconazole.

Symptoms: Vaginal irritation, greenish yellow frothy discharge, itching or irritation inside the penis, burning sensation after urination or ejaculation.

Treatment: Metronidazole.

Symptoms: Painful urination, pus, with complications such as PID (women).

Treatment: Ceftriaxone and azithromycin.