Unit 5 Flashcards
Spirochetes are made of all of the following except
Helicobacter
What structure is responsible for motility in spirochetes?
Periplasmic flagella
Factors that can play a role in pathogenicity of Leptospira include all the following except
Pancytopenia in host
What is a leptospira infection called when it becomes a severe system disease?
Weil Disease
All of the following symptoms are characteristic of Weil disease except
Pneumonia
An animal attendant at the zoo developed symptoms that included fever, chills, headache, severe myalgia and malaise. His urinalysis revealed the presence of protein and blood. A couple of weeks earlier, the attendant was handling the chimpanzees, and one of the chimps urinated on him. What is the most likely cause of illness?
Leptospira
Acceptable specimens during the first week of leptospirosis include which of the following
A and B
*CSF
*blood
What medium is used in the laboratory to grow leptospira organisms?
Fletchers
Leptospiral organisms are susceptible to all the following antimicrobial agents except
Penicillin
What diseases do Borrelia spp. cause?
Lyme diease and relapsing fever
What organism causes relapsing fever?
Borrelia recurrentis
How are borrelia organisms transmitters to the host?
Arthropods
What is the drug of choice of treating borrelia infections?
Tetracyclines
A young woman notices a red bruised like lesion that looks like a target on her lover leg. She cannot remember getting bruised, even though she went hiking through the woods last weekend. The bruise goes away in about a week and she thinks nothing more about it. About 2 weeks later, she develops joint and bone pain, extreme fatigue, and her heart just “doesn’t feel right” What disease she have and what antimicrobial agent is used to treat it?
Lyme disease and doxycycline
All of the following disease are produced by Treponema except
Elephantiasis
A man is taking a shower and notices lesion on his penis, this is not tender but firm with a clean surface and raised edges. He goes to his physicians. The physician orders a rapid plasmin Reagin (RPR) and dark-field microscopy. Both tests are positive. What is the probable diagnosis?
Syphilis
Where on the body is the secondary syphilis rash typically seen?
Palms and soles
When does an untreated patient develop teritiary syphilis?
Decades after the initial infection
All of the following are symptoms of teritiary syphilis, except
Encephalitis
How is congenital syphilis transmitted from the mother to her unborn child?
Crossing the placenta
Early onset congenital syphilis is characterized by all the following symptoms except
Encephalitis
What is the primary method used to screen for syphilis infections?
Serology
What is an example of a nontreponemal test?
RPR
The microscopic method of choice in detecting treponemes in clinical specimens
Dark field microscopy
What is the drug of choice used to treat syphilis?
Penicillin
Once infected with borrelia recurrentis, a 2-15 day incubation period follows where high numbers of organisms are found in the blood. The infected individual experiences high fever, rigors, severe headache, muscle pains and weakness. This febrile period lasts for about 3-7 days but ends quickly with the induction of an immune response. However, a similar but less severe course of symptoms recurs several days to weeks later. What causes this relapse?
The organism systematically changes its surface antigens during the course of a single infection
What organisms are considered obligate intracellular parasites?
Chlamydia
What organisms unique life cycle contains an elementary body (EB) and a reticulate body (RB)?
Chlamydia
What has an outer membrane similar to that of many gram-negative bacteria, with the most prominent feature being the major outer membrane protein?
EB
Chylamedia trachomatis is the infection agent in all the following conditions in humans, except
Pharyngitis
What disease, caused by Chlamydia trachomatis is considered a sexually transmitted disease where the organsims enter the lymph nodes near the genital tract, resulting in bubo formation and ultimately rupturing the lymph node?
LGV
All of the following are urogenital infections in men, produced by chlamydia trachomatis except
Orchitis
A young man goes to his physicians complaining of s discharge from his penis. The physician collects a slide for Gram stain and a swab for culture and sends them to the laboratory. The Gram stain reveals greater than 25 WBC/high-power field, no bacteria seen. The culture results after 48 hours show no growth. What is the most probable diagnosis and the organism responsible?q
Nongonococcal urethritis, chlamydia trachomatis
Chlamydia thrachomatis produces all the following conditions in adult women except,
Bacterial vaginosis
Infants can contract all the following chlamydia infections when passing through the birth canal except
Endocarditis
What is the preferred technique to rapidly detect chlamydia trachomatis in clinical specimens?
Nucleic acid amplification test (NAAT)
What method is used to confirm a positive chlamydia trachomatis EIA?
NAAT
Why are antibody detection methods for chlamydia trachomatis infection severely limited in the knowledge the provide the physician?
Many people have antibiotics from previous infections, and local infections do not cause great increases in antibody levels
An invasive genital disease associated with buboes in the groin describes an infection caused by
Chlamydia trachomatis
What testing method is the method of choice for detecting antibodies to chlamydophila pneumoniae?
Microimmunofluorescence
What disease does chlamydophila psittaci cause in humans?
Parrot fever
A 4-day-old infant shows symptoms of conjunctivitis. A Geimsa stain of the conjunctival scraping shows pernicular cytoplasmic inclusions. This organism is most likely
C. Trachomatis serovars D-K
What organism causes Rocky Mountain spotted fever?
R. Rickettsii
What organism causes endemic typhus?
Rickettsia typhi
What organism causes epidemic louseborne typhus?
R. Prowazekii
What organis causes human monocytic ehrlichipsis (HME) and uses the lone star tick (Amblyomma American um) as its primary vector?
Ehrlichia chaffeensis
All of the following diseases are associated with chlamydia trachomatis, except
Undulant fever
Diseases caused by rickettsial organisms are typically transmitted to humans by
An arthropod vector
Fifty years after this release from concentration camp, a man develops signs and symptoms of typhus. He currently has no known contacts or source of disease exposure; however, he may have had it in 1945 when he experienced similar symptoms. What is the most likely current diagnosis?
Brill-Zinsser syndrome
What is the name of test used to detect rickettsial agents?
Weil-Felix
Mycoplasmas are different from most other bacteria because they do not have a _______
Cell wall
One of the factors that allows Mycoplasma to infect the respiratory tract and the urogenital tract is that
They adhere to the epithelium of mucosal surfaces an d are not eliminated by mucus secretions
What infections agent causes the condition primary atypical pneumonia?
M. Pneumonia
At-risk for contacting walking pneumonia include all the following except
Preschool children
What two organisms are associated with urogenital tract infections but have also been isolated from asymptomatic individuals’?
Mycoplasma hominis and ureaplasma Urealyticum
When Mycoplasma hominis invades the upper GI tract, it can cause the following:
All of the above
*salpingitis
*pyelonephritis
*pelvic inflammatory disease
What organism has been recovered in Normal, sexually active females but is also associated with chorioamnionitis, congenital pneumonia, and development of chronic lung disease in premature infants?
Ureaplasma Urealyticus
If a newborn has symptoms of meningitis but the CCSF is negative for both Gram stain and routine culture, what organisms should be suspected?
Mycoplasma hominis and ureaplasma Urealyticum
When transporting specimen for mycoplasma culture to the laboratory, extreme care must be taken so that the specimen does not
All of the above
*dry out
*become contaminated
*become overgrown with bacterial normal biota
What time frame is suitable for blood draws from serologic testing to diagnose Mycoplasma infections?
Onset of symptoms and 2-3 weeks later
What test method is the most commonly used to detect antibodies to mycoplasma spp.?
EIA
All of the following antimicrobial agents are used to treat mycoplasma infections, except
Penicillin
Mycoplasma spp. from patient samples are visible by which staining technique?
Acridine orange
Which of the following methods is used to determine the presence of growth in mycoplasma broth media?
Change in phenol red pH indictator
A 10B broth inoculated with vaginal material turns alkaline after overnight incubation at 35C. Which of the following organisms should you suspect?
M. Hominis
Cultures for mycoplasma pneumonia should be incubated for ______
21 days or more
Which of the following stains is used to enhance the visibility of mycoplasma-like colonies?
Dienes stain
Mycoplasma organisms will grow in which of the following atmospheres?
All of the above
*ambient
*capnopilic
*anaerobic
Which of the following organisms was once called “T-strain mycoplasma?:
Ureaplasma spp.
Which factor is added to media to provide cholesterol for mycoplasma-like organisms?
20% fetal calf serum
What is the optimum incubation time for most mycobacteria associated with human diease?
2-6 weeks
What mycobacterium spp. fails to grow in vitro?
M leprae
All of the following are tradional characteristics used to identify mycobacteria except
Gram stain results
How are mucobacterial infections typically transmitted?
By air
When designing a mycobacteria laboratory, the designers should include all the following engineering controls to keep the workers safe, except
Positive air pressure
What is the single most important piece of equipment in a mycobacteria laboratory?
Biological safety cabinet
What is the recommended contact time for most disinfectants in mycobacteriololgy laboratory?
10-30 minutes
What is the purpose of the digestion-decontamination processing of specimens submitted for mycobacterial culture?
To allow the chemicals decontamination’s to kill nonmycobacterial organisms
Decontamination agents used in the decontamination-digestion process include all of the following except
Hydrochloric acid
All of the these stains are commonly used to visualize mycobacteria on a smear, except
Acridine orange
What media are recommended for routine culturing of specimens for the recovery of acid-fast bacilli?
Löwenstein-Jense(LJ) and liquid base media
What constituent of Lu medium is added to suppress the growth of gram-positive bacteria?
Malachite green
Middlebrook 7H10 and 7H11 media are enriched with all of the following except
Heme
What is the most sensitive and rapid primary isolation liquid media for mycobacterium spp?
Middlebrook 7H12
How long does it take to detect most mycobacterium spp. with the BACTEC method?
Less than 2 weeks
What medium is recommended for the recovery of mycobacterium haemophilum?
Chocolate
Microbiologist notices growth on a LJ slant that is buff color, rough and seems arranged in a cord. It has taken these organisms 4 weeks to grow. What is the most probable organism?
M. Tuberculosis
What are photochromogens?
Species that produce carotene pigment upon exposure to light
What are scotochrogens?
Species that produce pigment in the light or the dark
What are nonchromogens?
Species whose colonies remain buff colored after exposure to light
All of the following are biochemical tests for the identification of Mycobacterium spp., except
PYR
All of the following are biochemical tests from the identification of mycobacterium spp. except
Gelatin liquefaction
What component of mycobacteria is used for identification in nucleic acid hybridization assays?
Ribosomal RNA
How has the treatment of mycobacterial disease changed in light of the mutlidrug-resistant strains of mycobacteria that are being isolated?
Combinations of three of four drugs are used instead of a single drug
The CDC recommends all the following drugs for the treatment of mycobacterium tuberculosis, except
Ciprofloxacin
What classifies an organism as a multi-drug resistant tuberculosis?
Resistance to at least isoniazid and rifampin
What is the antigen used in the purified protein derivative (PPD) skin test?
A purified protein from the cell wall of M. Tuberculosis
A child presents to his physicians with fever, a nonproductive cough and shortness of breath. The physician orders a routine sputum culture and an acid-fast bacillus culture and smear. The smear snows red organisms arranged in ropes. What is the most probable cause of this child’s fever and cough?
M. Tuberculosis
If a person has had TB during his or her lifetime, how likely is it that the person will get the disease again?
5-15%
The most common non tuberculosis mycobacterium (NTM) infecting humans
M. Avium-intracellulare complex
A 35-year old man travels on a multidestination vacation over a 2 months period, including lengthy stops in tropical Africa and Southeast Asia. Six weeks after returning come home to the United States. He develops a productive cough, fatigue, weight loss, low-grade fever and night sweats. What disease should the physician consider as a result of his travel history?
TB
A patient with Hodgkin disease is feeling bad, so he visits his physician. The physicians clinical examination reveals submandibular lymphadenitis, subcutaneous nodules, painful swellings, ulcers progressing to abscesses and draining fistulas . What organism is probably producing these symptoms?
M. Haemophilum
This disease is slowly progressive, malignant and if untreated, life threatening. it is characterized by skin lesions and progressive, symmetric nerve damage. Lesions of the mucous membranes of the hose may lead to destruction of the cartilaginous septum, resulting in nasal and facial deformities. What disease is this?
Hansen disease
A sputum culture from a patient in Texas has buff colored colonies growing in approximately 4 weeks. After exposure to light, the colonies turn intense yellow. This isolate is most likely
M. Kansasii
All of following are examples of dimorphic fungi, except
Candidates albicans
A patient with very pale patches on his arms and legs is examined at his physicians office. His physicians orders a fungal culture. The Fungus culture. The fungus shows a “spaghetti-and-meatball” appearance on the direct smear. What organism is it?
Malassezia furfur
What is the causative agent of black piedra?
Piedraia Hortae
What is the causative agent of tinea Nigra?
Hortaea werneckii
All of the following organisms cause cutaneous mycoses except
Sporothrix schenckii
Chromoblastomycosis is caused by all the following organisms, except
Penicillium marneffei
What organism frequently presents in fungus ball?
Aspergillus fumigatus
What organism is one of the primary opportunistic infection in AIDS patients?
Pneumocystis jirovecii
For KOH to work properly, what is done to speed up the dissolution of the Keratin and skin layers?
Heat gently, then cool
