9. Unusual Bacteria Flashcards
A 48 year old man is brought to the ICU with severe pneumonia. In his patient history you see that he is unmarried and as an occupation he installs irrigation systems. Ten years ago he had a vasectomy and is not currently sexually active. Resent travel history he went to remote area of Saharan Algeria to install irrigation. He is allergic bananas and oysters. During examination he has no visible scarring or cuts on his body and body is a normal color. During oral examination his teeth and gums looked healthy and normal. He has been put on tradition antibiotic but with little success. For this reason it is suspected he has a rare bacterial infection. From this patient history which of the listed unusual Bacteria is most likely
A. Mycobacterium Marinum B. Nocardia Asteroids C. Mycoplasma genitalium D. Actinomyces israelii E. Mycobacterium leprae
RFA
Ans -B. Nocardia Asteroids- is the best answer since in his history he recently traveled to the very dusty and sandy Saharan desert and Nocardia Asteroids is usually transmitted by inhalation of suspended dust and causes pneumonia.
A. Mycobacterium marinum is found in water so working as an irrigation specialist he might get exposed but during examination his skin was normal and this is a skin infection
C. He isn’t sexually active and this infections spread via sexaul intercourse and presents ans burning urination with discharge in men which wasn’t noted
D. The part able the healthy teeth eliminated Actinomyces israelii lives between gums and teeth and cause painful abscesses in mouth, lungs, breast and GI tract
E. 95% of people are innate immune so unlikely it i Mycobacterium leprae also would present as nodular lesions which wasn’t noted and require close contact for transmission.
A 25 year old female was working in a remote hospital in Southern India. She developed a cough three weeks ago. An attending at the hospital gave her a prescription for steroids which did not improve her symptoms. She has returned to the US and is now in your office. You suspect an unusual bacteria and send a sputum sample to the lab. The lab uses ‘acid-fast’ staining technique due to which of the following characteristics of the cell?
A. Glycolipid cord factor B. Mycolic acid cell wall C. Periplasmic Space D. Hopanoids E. Lipoteichoic Acid
SZ
Ans B Mycolic acid
forms a waxy layer on the cell wall of Mycobacteria tuberculosis. By using the ‘acid-fast’ or Zielh-Neelsen technique Step 2 drives the stain into the waxy layer by putting the slide over heating and steaming it.
A. Glycolipid core factor is a characteristic of TB cells but is not the reason for the acid-fast technique. Core factors are toxic by disrupting oxidative phosphorylation.
C. Periplasmic space is a feature of Gram negative bacteria.
D. Hopanoids create rigidity and are essential for maintaining osmotic pressures in mycoplasma because there are no cell walls present.
E. Lipoteichoic Acid holds together layers of the cell wall and anchors them to the membrane in Gram positive cells.
A 65 year old man presents to your office for complaints of a red rash on his left forearm for one week. He states he was hiking in Colorado over the Fourth of July Holiday. He believed the rash was poison ivy and used a topical over the counter cream with little relief. He now states that his ‘armpit’ is painful and tender and he has been feeling unusually warm despite he warm temperatures of the summer. After examining the patient you conclude that the diagnosis may be which of the following?
A. Mycobacterium marinum B. Mycoplasm C. Rickettsia rickettsii D. Mycobacterium leprae E. Actinomyces gerencseriae
SZ
Ans. C Ricketssia rickettsii
or “Rocky Mountain Spotted Fever” is transmitted by a tick found in the southwestern part of the US. The arthropod attaches to the human, penetrates the skin or mucus membranes, and multiplies in endothelial cells. It can cause a petechial rash, lymphadenopathy, vasculitis, fever, weakness, and gangrene of the skin and tissues.
You are working for Doctor’s Without Borders in India. A 57 year old “untouchable” has come into the clinic she is covered with several nodular diffuse lesions containing many bacilli in poorly organized granulomas. What does she have?
A. Mycobacterium leprae, lepromatous form
B. Mycobacterium leprae, tuberculoid form
C. Mycobacterium tuberculosis, tuberculoid form
D. Mycobacterium tuberculosis lepromatous form
RFA
RFA
Ans. A. Mycobacterium leprae, lepromatous form is described as covered with several nodular diffuse lesions containing many bacilli in poorly organized granulomas.
B Tuberculoid form is discrete lesions consisting of well-organized granulomas having few bacilli
C & D can be thrown out simple because Tuberculosis doesn’t present like described and also so far Leprae is the only bacterium with two presenting forms we went over in depth.
A 29 year old man of kushmeri decent comes in with a burning urethra. You find ureaplasma. Is this gram +/-?
A) Gram +
B) Gram -
C) Acid Fast
D) Doesn’t stain
MM
Ans D b/c no cell wall
A dentist is complaining of a painful abscess in her boobs so she decided to go to a real doctor. You do some doctors stuff and find out its a gram + branching filamentous rod that is an obligate anaerobe. Which of the following is most likely the cause of the infection?
A. Mycobacterium marinum B. Mycoplasm C. Rickettsia rickettsii D. Mycobacterium leprae E. Actinomyces gerencseriae
MM
Ans E - usually found in orally
In the life cycle of chlamydia, elementary bodies are transformed to what type of molecule? (MG)
A. Barr body
B. Azurophilic body
C. Reticulate body
D. Erythrophilic body
C. Reticulate body
which then replicates and transforms back to elementary bodies before lysis
A married couple comes to the clinic complaining of different symptoms. The woman recently started having vaginal bleeding post-coitus, while the man has had a burning sensation during urination. What infection causes both of their symptoms? (MG)
A. Ureaplasma
B. Chlamydia
C. Mycoplasma genitalium
D. Nocardia asteroids/nocardiosis
C. Mycoplasma genitalium
Different symptoms in women than in men.
A-C are all STD’s, while D is contracted through inhalation of organisms suspended in dust
Which of the following is not an Obligate Intracellular Parasite?
A. Legionella Pneumophila
B. Rickettsia Rickettsii
C. Chlamydia Trachomatis
D. Mycobacterium leprae
FA
A. Legionella, although can be intracellular at times, is not obligated to remain within a host cell
Which of the following molecules gives Mycobacterium T. the ability to disrupt oxidative phosphorylation of host cells?
A. Mycolic Acid
B. Cord factor
C. Sulfatides
D. Carbol fuchsin
FA
B. Cord Factor is a highly toxic Glycolipid that is able to disrupt Oxidative phosphorylation.
Sulfatides are Glycolipids within the cells that disrupt the fusion of lysosomes with phagosomes, preventing formation of the phagolysosome.
Carbol Fuchsin is the dye used in Fast acid staining of Tb.
