Microbial Diseases of the Respiratory System

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Questions and Answers

Which of the following bacteria is responsible for causing Pertussis?

Mycobacterium tuberculosis

Mycobacterium bovis

Bordetella pertussis (correct)

Streptococcus pneumoniae

What is the virulent factor of B. pertussis?

Pertussis toxin

Tracheal cytotoxin and Pertussis toxin

Tracheal cytotoxin

Capsule (correct)

What is the primary mode of transmission of Tuberculosis?

Contaminated milk or food

Direct contact with an infected person

Infected water

Inhaling the bacillus (correct)

What is the name of the vaccine available against Tuberculosis?

BCG vaccine Signup and view all the answers

What is the term used to describe pneumonia caused by microorganisms other than Streptococcus pneumoniae?

Atypical pneumonia Signup and view all the answers

What is the term used to describe the inflammation of the middle ear?

Otitis media Signup and view all the answers

What is the typical duration of treatment for Brucellosis with antibiotics?

10 to 15 days Signup and view all the answers

Which of the following animals is commonly infected with Brucella melitensis?

Goats Signup and view all the answers

What is the primary mode of transmission of Bacillus anthracis?

Direct contact with infected animals Signup and view all the answers

What is the characteristic skin lesion of Cutaneous Anthrax?

An ulcerated area with a black eschar Signup and view all the answers

What is the primary virulence factor of Bacillus anthracis?

Two exotoxins Signup and view all the answers

What is the form of Anthrax caused by ingestion of undercooked food containing anthrax endospores?

Gastrointestinal Anthrax Signup and view all the answers

What is the primary cause of gangrene?

Infection by C. perfringens Signup and view all the answers

What is the primary mode of transmission of plague?

Flea bites Signup and view all the answers

What is the treatment of choice for pneumonic plague?

Gentamicin and fluoroquinolones Signup and view all the answers

What is the primary symptom of Lyme disease?

Rash at the bite site Signup and view all the answers

What is the primary cause of inhalational anthrax?

Infection by B. anthracis Signup and view all the answers

What is the primary method of preventing gangrene?

Prompt cleaning of serious wounds Signup and view all the answers

What is the third phase of Lyme disease?

Development of arthritis that may affect for years Signup and view all the answers

What is the primary cause of Burkitt's Lymphoma?

Epstein-Barr virus (human herpesvirus 4) Signup and view all the answers

What is the typical incubation period for Infectious Mononucleosis?

4 to 7 weeks Signup and view all the answers

How is Cytomegalovirus typically transmitted?

Through kissing, sexually, by transfused blood, and by transplanted tissue Signup and view all the answers

What is the treatment for Cytomegalovirus retinitis?

Ganciclovir Signup and view all the answers

What is the characteristic of infected B cells in Infectious Mononucleosis?

Production of heterophile antibodies Signup and view all the answers

What is the percentage of AIDS patients who exhibit a CMV-caused eye infection?

85% Signup and view all the answers

Study Notes

Microbial Diseases of the Upper Respiratory System

Pertussis (Whooping Cough) is caused by Bordetella pertussis, an obligately aerobic, gram-negative coccobacillus.
The virulent factor is the capsule, and B. pertussis produces several toxins, including tracheal cytotoxin, which damages ciliated cells.
Pertussis toxin enters the bloodstream and is associated with systemic symptoms, causing gasping for air between coughs, resulting in a whooping sound.
Diagnosis is made by isolating the pathogen from a throat swab, and treatment involves antibiotics, commonly erythromycin or other macrolides.

Tuberculosis

Caused by Mycobacterium tuberculosis, an obligate aerobe rod.
M. bovis causes bovine tuberculosis, transmitted to humans through contaminated milk or food, affecting bones or the lymphatic system.
Mycobacterium bacteria can survive for weeks in dried sputum and are highly resistant.
Tuberculosis is typically acquired by inhaling the bacillus, which reaches the lungs and is phagocytized by a macrophage in the alveoli.
Symptoms include coughing, bloodstained sputum, and potentially fatal hemorrhaging.
Diagnosis involves a tuberculin skin test, chest X-ray, CT scan, and microscopic examination of smears.
Treatment involves antibiotics, and a BCG vaccine is available.

Bacterial Pneumonias

Streptococcus pneumoniae causes typical pneumonia, while other microorganisms (fungi, protozoa, viruses, and bacteria) cause atypical pneumonia.
Lobar pneumonia affects the lobes of the lungs, while bronchopneumonia affects the alveoli adjacent to the bronchi.
Treatment involves antibiotics, such as streptomycin, administered for 10 to 15 days.

Brucellosis

Brucellosis is the world's most common bacterial zoonosis, often becoming chronic and affecting any organ system.
Brucella bacteria are small, aerobic, gram-negative coccobacilli that easily become airborne and are considered dangerous to handle.
The incubation period is usually 1-3 weeks, but can be longer, with symptoms including fever, malaise, night sweats, and muscle aches.
Treatment involves antibiotics.

Anthrax

Caused by Bacillus anthracis, an endospore-forming bacillus that can survive in soil for up to 60 years.
People at risk are those who handle animals, and the disease has three forms: cutaneous, gastrointestinal, and inhalational.
Cutaneous anthrax occurs through contact with infected material, causing a papule, vesicles, and a black eschar.
Gastrointestinal anthrax is caused by ingesting infected food, leading to nausea, abdominal pain, and bloody diarrhea.
Inhalational anthrax occurs through inhaling endospores, causing mild fever, coughing, and chest pain, with a high mortality rate.
Treatment involves antibiotics, such as doxycycline or ciprofloxacin, and prevention is possible through vaccination.

Gangrene

Ischemia, or interrupted blood supply, causes a wound to become anaerobic, leading to necrosis or tissue death.
The death of soft tissue resulting from the loss of blood supply is called gangrene, often a complication of diabetes.
C. perfringens is a common cause of gangrene, leading to gas gangrene.
Treatment involves the surgical removal of necrotic tissue and amputation, with prevention possible through prompt cleaning of serious wounds and precautionary treatment with penicillin.

Vector-Transmitted Diseases

Plague

Caused by Yersinia pestis, transmitted through rat fleas (Xenopsylla cheopis) to humans.
There are three types of plague: bubonic, septicemic, and pneumonic.
Treatment involves gentamicin and fluoroquinolones, with diagnosis made by isolating bacteria.
A vaccine is available.

Lyme Disease (Lyme Borreliosis)

Caused by Borrelia, transmitted through tick bites, with a reservoir in field mice and other animals.
The first symptom is a rash at the bite site, followed by flulike symptoms in a couple of weeks.
Treatment involves antibiotics, with non-effective treatment potentially affecting the heart and leading to irregular heartbeat.
The second phase involves chronic neurological symptoms, such as facial paralysis, fatigue, and memory loss.
The third phase involves arthritis that may affect multiple joints for years.
Diagnosis is made through serological tests.

Viral Diseases of the Cardiovascular and Lymphatic Systems

Burkitt's Lymphoma

A tumor of the jaw caused by Epstein-Barr virus (human herpesvirus 4), transmitted through a mosquito vector.
Treatment involves anticancer drugs.

Infectious Mononucleosis

Caused by Epstein-Barr virus, transmitted through saliva (kissing, sharing drinking vessels).
Childhood infections are usually asymptomatic, while adulthood infections are more symptomatic due to an intense immunological response.
The incubation period is 4-7 weeks, with symptoms including heterophile antibodies produced by infected B cells.
The infected B cells produce heterophile antibodies that are used in the diagnosis of mononucleosis.

Cytomegalovirus Infections

Caused by human herpesvirus 5, escaping antibody action by moving between cells in contact.
Transmitted through kissing, sexually, by transfused blood, and by transplanted tissue.
Immunocompromised individuals are at risk for life-threatening pneumonia, with almost any organ potentially affected.
About 85% of AIDS patients exhibit a CMV-caused eye infection, Cytomegalovirus retinitis, which can result in eventual loss of vision without treatment.
Treatment involves Ganciclovir, with vaccines under development but currently unavailable.

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Description

Learn about bacterial diseases affecting the upper and lower respiratory systems, including pertussis (whooping cough) and its causes, symptoms, and effects.