Micro Lesson 7 Bacteria

Micro Lesson 7 Bacteria - Lesson 9 : Lesson Bacteria in the...

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Unformatted text preview: Lesson 9 : Lesson Bacteria in the dental Bacteria environment environment DEA 1135 Introduction to Microbiology The oral cavity is a common site for manifestations of systemic microbial diseases. Oral lesions may be typical of those seen elsewhere on the body, or the lesions may be modified by the local environment. The ease of examination within the oral cavity, however, and any site-specific features facilitates diagnosis of the systemic condition. Bacterial Infections Bacterial I. SYPHILIS (Lues) II. GONORRHEA III. TUBERCULOSIS IV. ACTINOMYCOSIS V. TETANUS V. I. Syphilis I. •Syphilis is a complex sexually transmitted disease (STD) caused by the bacteria Treponema pallidum. If detected and treated, syphilis can be cured with antibiotics. If untreated, syphilis may linger and progress in a stepwise fashion to later stages. •The most common way syphilis bacteria enter the body is through mucous membranes. Once infected, a person can pass the disease to others (is contagious) whenever a sore or a rash is present. •Symptoms of syphilis may be unnoticed or may mimic many other diseases. This may cause an infected person to delay seeking medical care or may make diagnosis difficult. •Different stages of syphilis have different symptoms. The 4 distinct stages of syphilis are referred to as primary, secondary, latent (hidden), and tertiary (late). •Sores mainly occur on the external genitals, vagina, anus, or rectum. Sores can also occur on the lips and in or around the mouth. The bacteria most commonly enter the body through mucous membranes, usually in the area around the genitals and urinary system. •Other, rare ways syphilis can enter the body include through openings in the skin, such as cuts and scrapes or even through wet kisses, if the infected person has a sore on the mouth or lips. •Syphilis may also be transmitted by using a needle previously used by an infected person. •Syphilis can be transmitted through a blood transfusion, but this is very rare. •Transmission depends on direct contact with active lesions. T. pallidum enters the body through abrasions and penetrates mucous membranes, migrating to the lymphatic system. •The organism incubates for 10­90 days after which a chancre develops at the site of inoculation. Syphilis (Primary stage) Syphilis •The first symptom of syphilis is a sore called a chancre (pronounced shanker) that is usually painless. The sore begins at the site of infection as a small, solid, raised skin sore less than1 cm (0.39 in.) across. •It develops into a red, usually painless open sore with a scoopedout appearance. The sore usually does not bleed. Oral lesions are most commonly seen on the lips The oral lesion presents as a painless, clean-based ulceration. Two or more chancres may develop at the same time, usually in the genital area, but sometimes on the hands, mouth, or other body surfaces. Chancres contain millions of syphilis bacteria and are highly contagious. This primary lesion heals typically within 3 to 6 weeks. The patient may feel that the infection is over but about 68 weeks after the appearance of the chancre, the secondary stage begins. Syphilis (secondary stage) Syphilis During this stage, there are cutaneous and mucous membrane lesions that contain the T. pallidum organism that appear on the lips, throat, penis, vagina and other body surfaces. begins 6-8 weeks after primary stage starts malaise, headache, low-grade fever, weight loss, general aches mucous patches seen intraorally heal in 2-10 weeks without scarring Mucous patch Mucous These lesions are called mucous patches and they are distinctive for the secondary stage of syphilis. There may be additional symptoms such as headache, low­grade fever, and enlargement of the lymph nodes. Syphilis (latent stage) Syphilis After the secondary stage, syphilis enters a latent period during which there are no clinical symptoms. The latent period marks the end of the infectious period of syphilis. During this latent stage, the bacterium is spreading throughout the body into all the tissues and organs. dormancy period of 4-7 years with no signs and symptoms Syphilis (tertiary stage) Syphilis •The third or tertiary stage of syphilis does not begin until years after the initial infection. •Third stage of syphilis includes the most serious of all complications. Aneurysm of the ascending aorta due to effects on vascular system (i.e. arteritis). Granulomatous inflammation can affect the skin, mucosa, soft tissue, etc. This zone of granulomatous inflammation, known as a gumma, presents as an indurated, nodular, or ulcerated lesion which.on occasion may be associated with a large amount of tissue destruction. •During the third stage, damage can occur in any organ of the body that arise from cell­mediated immunity and hypersensitivity to the treponemal organism. widespread systemic disease cardiovascular and neurological involvement appearance of a gumma, a painless elastic tumor with a necrotic center patient is no longer infectious Gumma Gumma •The third stage of syphilis is characterized by the formation of a gumma. •Gummas are nodular lesions characterized by a granulomatous inflammation. •Presents as an indurated, nodular, or ulcerated lesion which on occasion may be associated with a large amount of tissue destruction. •Gummas may be in any organ. It develops in 15% of untreated cases within 110 years after infection.. Intraoral involvement most frequently affects the palate or tongue. When the palate is involved, the ulceration can perforate to the nasal cavity. Syphilis (congenital) Syphilis •Syphilis can be transmitted from mother to fetus resulting in stillbirth or birth defects such as mental retardation and neurological abnormalities. •If the pregnancy occurs during the first or second stage of syphilis, a stillbirth is more likely. •If the disease is in the latent stage, congenital deformations are usually the result. •If untreated, all children born with syphilis develop secondary and tertiary syphilis. The infected children do not live long enough. Syphilis (congenital) Syphilis Transmitted by mother to Transmitted fetus fetus Can cause developmental Can deformations deformations High arched palate, short High mandible mandible Saddle nose Saddle Mulberry molars Hutchinson’s incisors Hutchinson’s Congenital syphilis Congenital In the oral cavity, we'll see deformations in the teeth known as Hutchinson's incisors and Mulberry molars. The maxillary incisors will have a characteristic notch in the incisal edge with possibly some brown discoloration. Mulberry molars are typically seen on the maxillary and mandibular first molars and appear to be smaller than the secondary dentition and have more developmental lobes. The microorganism is easily treated with penicillin or other antibiotics during the early stages. Bacterial infections continued: Bacterial II. Gonorrhea II. Gonorrhea is a sexually transmitted disease caused by the gram- diplococcus Neisseria gonorrhoeae. This bacterium adheres to the lining of the GI tract during sex and infects the mucosal cells lining the epithelium. •It spreads to the urethra, cervix, rectum, pharynx and conjunctivae. •N. gonorrhea is readily killed by drying and exposure to metals and cannot be transmitted by inanimate objects because of its susceptibility to desiccation. It's usually a self-limiting disease, but both sexes can have widespread infection to the GU tract and other parts of the body. Picture of Gonorrhea virus •Orally, gonorrhea is sometimes seen in the newborn due to infection as the child travels through the birth canal; others through autoinoculation and in adults through oro-genital sexual relations •In the mouth and pharynx one can find, after 1 to 3 days of incubation, a flu-like stomatitis or pharyngitis, with lemon yellow colored pseudomembranous exudate present. Secretions, as well as bleeding, are also present in the gingival. The disease may pass inadvertently in the mouth and pharynx Most woman remain asymptomatic carriers of the disease but spread of the disease can cause PID, ectopic pregnancies and chronic infection of the fallopian tubes. The incubation period is less than a week and damage to any organs or body structures usually heals with scarring. Antibiotics like penicillin are the drug of choice for gonorrhea although some resistant strains may require higher strength drugs like tetracycline, cephalosporins or streptomycin. Incubation period less than a week Transmitted by mucous membrane direct Transmitted contact contact Can cause oral complications (red inflamed Can mucosa, erosive ulcers, pharyngitis) mucosa, Treated with antibiotics III. Tuberculosis III. M. tuberculosis is a highly contagious, airborne, rod-shaped highly organism (bacillus) that thrives on oxygen, grows slowly, and possesses a "waxy" cell wall. The cell wall's structure and possesses cell function are not well understood but appear to allow the bacteria to survive within immune cells called macrophages (specialized cells that destroy bacteria and viruses). It also provides the organism with a resistant barrier to many common drugs. The bacteria's primary host is the human. Infection spreads The human Infection through direct person-to-person contact. When an infected direct person talks, coughs, sings, or spits, tiny aerosolized droplets containing bacteria are released into the air and inhaled by uninfected persons. Viable bacteria can remain in the air for a long time. long In 1993, the WHO (World Health Organization) declared In tuberculosis a global emergency. Tuberculosis (TB) is responsible for more deaths than any other infectious disease. deaths Once called consumption, TB is a highly contagious, Once persistent disease characterized by the formation of hard grayish nodules, or tubercles. Because its signs and symptoms are easily confused with those Because of many other (usually respiratory) diseases, tuberculosis can be difficult to diagnose. Common symptoms are cough that is cough worse in the morning and may include hemoptysis (i.e., blood in the sputum), chest pain, night sweats, and breathlessness (dyspnea). Incidence & Prevalence Of Tuberculosis Tuberculosis Mycobacterial disease is one of the world's most Mycobacterial difficult health problems. One-third of the population One-third worldwide is infected with TB. Of these, 8 to 10 million develop active disease and 3 Of million die each year. It is the greatest cause of death in women of reproductive age; 900 million women are currently infected. Of these, 2.5 million will develop active disease and 1 million will die. TB lymph node involvement TB Because of the chronic and persistent nature of the disease, effective treatment involves long­term multiple antibiotic treatment. Patients who are malnourished, under stress or afflicted with a compromised immune system are more prone to contracting TB, and with the outbreak of drug­resistant strains, eliminating TB is a difficult and costly affair. The rate of tuberculosis infection in the United States had been declining steadily until 1984 and then increased. Numerous factors account for the resurgence of tuberculosis in Numerous the United States and in Europe. They include the following: Emergence of multi drug-resistant strains of M. tuberculosis Emergence drug-resistant M. Erosion of systems for diagnosis and treatment of the disease Erosion Immigration of infected persons from countries where TB is prevalent Prevalence of HIV (human immunodeficiency virus) infection Prevalence HIV and AIDS Reactivation of disease in the elderly Reactivation Socioeconomic decline in urban areas Caused by M tuberculosis Transmitted through airborne droplets Lower respiratory inflammation lesions Lower confirmed by chest film confirmed Fatigue, weight loss, fever Treated with long term antibiotics IV. ACTINOMYCOSIS IV. An infection of filamentous, branching, gram-positive An anaerobic bacteria. anaerobic Actinomycetes are normal saprophytic components of Actinomycetes the oral flora. Documented sites of colonization in healthy patients include the tonsillar crypts, dental plaque and calculus, carious dentin, gingival sulci, and periodontal pockets. Actinomyces israelii is the most common culprit in Actinomyces clinical infections. clinical CLINICAL FEATURES: CLINICAL The most common sites of involvement in The actinomycosis are the cervicofacial, abdominal, thoracic, cutaneous, and genital regions. More than 50% of cases arise in the cervicofacial More cervicofacial region. region. The suppurative reaction of the infection may The discharge large yellowish flecks that represent discharge colonies of the bacteria called sulfur granules. colonies In the cervicofacial region, the organism typically In enters tissue through an area of prior trauma. trauma Direct extension through soft tissue is seen, and lymph nodes become involved only if they are in the path of the process. V. TETANUS V. The bacterium Clostridium tetani produces a neurotoxin that interferes with the peripheral nerves of the spinal cord in the central nervous system. This neurotoxin inhibits the ability of these nerve cells to properly transmit signals to the muscle cells, causing the symptomatic spastic paralysis of tetanus because the muscle fibers are unable to relax in between contractions. “Lock Jaw” •The bacteria is widely found in soil and transmission is usually through contaminated deep puncture wounds. If the wound environment becomes anaerobic, then the bacterium has an opportunity to multiply and allow its neurotoxin to spread systemically. It's not just a disease of rusty nails, but any soil contaminated injury. The microorganism has an incubation period of 3­21 days and can be prevented by immunization and booster injections. Caused by C tetani Caused tetani Neurotoxin interferes with peripheral spinal Neurotoxin cord nerves cord Found in soil and transmitted through deep Found wounds wounds 3-21 day incubation period Prevented by immunization Treated with antitoxin Patients with tetanus Patients After inoculation, tetanus can be treated by an antitoxin to block the action of the neurotoxin, but if left untreated, tetanus is frequently fatal. Prevention: Tetanus vaccine Prevention: Infants should receive DTP vaccine as part of their routine Infants immunization. immunization. Adults should be given a routine booster dose of Td every 10 Adults booster years. Adults without documentation of ever receiving the basic series Adults of tetanus and diphtheria toxoids should first receive a primary series of three doses. series If someone experiences a deep or puncture wound, or a wound contaminated with dirt, an additional booster dose may be given if the last dose was more than five years ago. It is important to keep an up-to-date record of all immunizations It record so that repeat doses don't become necessary. Although it is vital to be adequately protected against tetanus, receiving more doses than recommended can lead to increased local reactions, such as painful swelling of the arm. painful ...
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This note was uploaded on 08/19/2011 for the course DEA 1135 taught by Professor Guilford during the Spring '05 term at Gulf Coast Community College.

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