ORPTH ADONS INFX: BACT,VIR, MYCO Flashcards
1
Q
- Scarlet fever is caused by _______ Streptococci.
(a) β-hemolytic
(b) α-hemolytic
(c) λ-hemolytic
(d) δ-hemolytic
A
- (a) Streptococci are classified according to the presence/
absence of hemolysis around their colonies on blood Agar.
Thus α hemolytic streptococci produce narrow zone of
partial hemolysis, β hemolytic produce clear, translucent zone of complete hemolysis, while γ hemolytic produce no
hemolysis.
2
Q
- Identify which one out of the following is not a predisposing factor
of candidiasis.
(a) Radiation therapy
(b) Prolonged antibiotic usage
(c) Exertion
(d) Immunodeficiency
A
- (c) Candidiasis is caused by a yeast-like fungus Candida
albicans and is a common inhabitant of oral cavity.
Amongst the many predisposing factors some are acute
and chronic diseases like TB, diabetes, immunodeficiency,
nutritional deficiency, prolonged hospitalization, prolonged
antibiotic usage, radiation therapy, old age, infancy, poorly
maintained dentures, etc
3
Q
- The chief oral manifestation of scarlet fever is
(a) Stomatitis nicotina
(b) Stomatitis scarlatina
(c) Stomatitis palatina
(d) Stomatitis uvea
A
- (b) Mucosae of palate, throat, tonsils faucial pillars appear red,
swollen and sometimes covered by a grayish exudate.
4
Q
- The mode of transmission of C. diphtheriae is
(a) Blood-borne
(b) Water-borne
(c) Animal vectors
(d) Air-borne
A
- (d) Transmission of C. diphtheriae occurs via respiratory
droplets. These organisms reside in throat, nose and skin
of patients, upto 3 months after infection
5
Q
- The pseudomembrane in diphtheria is mainly seen on
(a) Tongue (b) Larynx
(c) Tonsils (d) Trachea
A
- (c) The pseudomembrane begins as a patchy, yellowish white
film that thickens to form an adherent gray covering. Over
a period of time, the membrane may develop patches of
green/black necrosis
5
Q
- One of the following is not a complication ensuing from infection
with C. diphtheriae
(a) Trigeminal neuralgia
(b) Otitis media
(c) Acute circulatory failure
(d) Myocarditis
A
- (a) Systemic complications like acute circulatory failure,
myocarditis, otitis media, etc. are caused by circulating
toxins due to ensuing bacteremia
6
Q
- Which of the following is not a feature of Mycobacterium
tuberculosis bacteria?
(a) Aerobic
(b) Acid fast
(c) Anaerob
ic (d) Nonspore forming
A
- (c) Mycobacterium species of bacteria are aerobic, acid-fast,
nonsporing, slender bacilli. As their cell walls contain long
chain fatty acids, they do not take up Gram stain, instead a
special stain, Ziehl-Neelsen stain is used to visualize them.
7
Q
- The giant cells found in a tubercular granuloma are called as
(a) Langerhans giant cells
(b) Langhans giant cells
(c) Touton giant cells
(d) Reed-Sternberg Giant cells
A
- (b) Tuberculosis is characterized by formation of circumscribed collection of epithelioid histiocytes, lymphocytes, multinucleated giant cells called Langhans giant
cells and central areas of caseous necrosis. The giant cells
are characteristic of granulomatous infections and are
characterized by dozens of nuclei arranged in a horseshoe
pattern inside the cell.
8
Q
- Calcification of the necrotic material in later stages of TB is called
(a) Russell complex
(b) Rouleaux complex
(c) Langhan’s complex
(d) Ranke complex
A
- (d) Ranke complex is a radiologically detectable region of
calcification inside the Ghon focus, which is a 1–1.5 cm area
of grayish white inflammation with central area of caseous
necrosis in most cases. This lesion constitutes the tubercular
granuloma histologically
9
Q
- All except ______ are components of tubercular granuloma.
(a) Lymphocytes
(b) Multinucleated giant cells
(c) Neutrophils
(d) Basophil
A
- (b) A typical tubercle granuloma is a circumscribed collection
of epithelioid histiocytes, lymphocytes and multinucleated
giant cells often but not always surrounding central areas
of caseous necrosis.
10
Q
- The tuberculin test is also called as
(a) Rouleaux test
(b) Monroe test
(c) WIDAL test
(d) Mantoux test
A
- (d) Mantoux test is done to determine if an individual is
hypersensitive to the tubercle antigen. This reaction
develops 2–4 weeks after initial exposure to the tubercle
antigen. A positive reaction, however, only indicates the
exposure of the individual to the microorganism and does
not signify active disease, which can only be confirmed by
demonstration of the mycobacterium by special stains and
culture of infected sputum or tissue specimen.
11
Q
- Hansen’s disease is another name for
(a) TB
(b) Leprosy
(c) Tetanus
(d) Syphilis
A
- (b) Leprosy is a chronic, granulomatous disease caused by
Mycobacterium leprae
12
Q
- Which is the only bacterium amongst the following to infect the
peripheral nerves?
(a) M. tuberculosis
(b) C. diphtheriae
(c) T. pallidum
(d) M. leprae
A
- (d) Nerve involvement in leprosy is primarily of the facial and
trigeminal nerves. Facial paralysis may be unilateral or
bilateral. Sensory deficit may affect any branch of trigeminal
nerve but maxillary division is most commonly affected.
13
Q
- Sulfur granules found within pus from the abscess is a
characteristic feature of
(a) Leprosy
(b) Diphtheria
(c) Actinomycosis
(d) Syphilis
A
- (c) Sulfur granules in actinomycosis represent suppurative
reaction of this disease which discharges yellowish flecks
containing colonies of the bacteria.
14
Q
- Which other infection apart from actinomycosis produces sulfur
granules?
(a) Mucormycosis
(b) Cryptococcus
(c) Histoplasmosis
(d) Botryomycosis
A
- (d) Botryomycosis represents an unusual host reaction to
S. aureus and certain other bacteria.
15
Q
- Which disease, also called as “Lock jaw” is characterized by
intense activity of motor neurons resulting in severe muscle
spasms?
(a) TB
(b) Tetanus
(c) Botulism
(d) Histoplasmosis
A
- (b) Symptoms of intense muscle spasms is produced by
the exotoxin of the anaerobic Gram-positive bacterium
Clostridium tetani. The exotoxin acts at the synapse of motor
neurons and interneurons of inhibitory pathways to produce
blockade of spinal inhibition
16
Q
- ______ is also referred to as “Thrush”.
(a) Acute atrophic candidiasis
(b) Chronic hyperplastic candidiasis
(c) Chronic atrophic candidiasis
(d) Acute pseudomembranous candidiasis
A
- (d) Thrush is one of the most common form of candidiasis,
occurring at any age, but especially prone to occur in
debilitated or chronically ill patients.
17
Q
- Which one of the following is a predisposing factor of Noma?
(a) Central giant cell granuloma
(b) Dentin dysplasia
(c) Diphtheria
(d) Congestive cardiac failure
A
- (c) Predisposing factors play a crucial role in development
of Noma, as it occurs primarily in persons who are either
malnourished or debilitated from severe systemic infections
like diphtheria, dysentery, measles, pneumonia, scarlet
fever, TB and blood dyscrasias, etc.
18
Q
- Explosive and widespread form of secondary syphilis is termed
as
(a) Chancre
(b) Gumma
(c) Lues maligna
(d) Condyloma
A
- (c) Seen in secondary stage of acquired syphilis, it is
characterized by diffuse eruption of skin and mucous
membranes which are usually maculopapular in nature.
More commonly seen in HIV positive patients
19
Q
- Cat scratch disease is caused by
(a) Herpes simplex
(b) Human papilloma virus
(c) Vincent organism
(d) Bartonella henselae
A
- (d) B. henselae belong to the phylum proteobacterium which
includes other bacteria like Escherichia, Salmonella,
Helicobacter, Vibrio, etc. B. henselae are primarily implicated
in causing cat scratch disease.
20
Q
- Pyogenic granuloma can best be classified as a ______ disease.
(a) Neoplastic
(b) Reactive
(c) Infectious
(d) Autoimmune
A
- (b) Earlier considered to be an infection caused by pyogenic
organisms, it is now understood to be an exuberant tissue
response to local irritation or trauma. It is characterized by
a highly vascular proliferation histologically.
21
Q
- Cold sores are caused by _____ virus.
(a) Herpes simplex
(b) Herpes zoster
(c) Cytomegalovirus
(d) Rubella
A
- (a) Cold sores are better known as herpes labialis or herpetic
gingivostomatitis and are caused by herpes simplex 1 virus,
which affects the face, lips, oral cavity and upper body skin.
22
Q
- Lipshütz bodies are intranuclear inclusions seen typically in the
cells of patients affected with
(a) Chickenpox
(b) Herpangina
(c) Smallpox
(d) Herpetic stomatitis
A
- (d) Lipshütz bodies are eosinophilic, ovoid, homogeneous
structures within the nucleus of affected cells. These
structures then displace the nucleolus and nuclear
chromatin peripherally which produces a periinclusion
halo.
23
Q
- One of the following is not a histological feature associated with
herpes simplex infection
(a) Ballooning degeneration of cells
(b) Lipshütz bodies
(c) Subepithelial vesicle/bulla formation
(d) Multinucleated giant cells
A
- (c) The vesicles/bullae formed in herpes simplex infection are
intraepithelial in nature as there is marked degeneration of
epithelial cells
23
Q
- Herpetic whitlow is an infection of _____ with HSV 1.
(a) Finger (b) Abdomen
(c) Genitals (d) Conjunctiva
A
- (a) Herpetic whitlow or herpetic paronychia is caused by selfinoculation in children with orofacial herpes.
24
Q
- Herpangina is caused by _____ virus.
(a) Epstein-Barr
(b) Papovavirus
(c) Varicella zoster
(d) Coxsackie group A
A
- (d) Coxsackievirus A belongs to the genus enterovirus which
also includes other viruses like poliovirus, coxsackievirus,
echovirus, etc.
25
Q
- Which amongst the following organisms has a special predilection
for spleen, liver, lymph nodes and bone marrow?
(a) Actinomyces
(b) Histoplasma
(c) Candida
(d) Treponema
A
- (b) Histoplasma is a generalized fungal infection and is
acquired by inhalation of spores mainly from excreta of
birds. Since the organisms have a special predilection for
reticuloendothelial system, liver, lymph nodes, spleen
and bone marrow, it manifests as hepatosplenomegaly,
lymphadenopathy, fever, cough, etc
25
Q
- The most common site involved in rhinosporidiosis is
(a) Larynx
(b) Pharynx
(c) Nasal cavity
(d) Skin
A
- (c) Rhinosporidiosis is a chronic granulomatous fungal disease,
affecting mainly the oropharynx and the nasopharynx as
well as larynx, skin, eyes and the genital mucosa.
26
Q
- Erythematous candidiasis occurs most commonly as a result of
(a) Sequela to course of broad spectrum antibiotics
(b) Irritation from dentures
(c) Immunodeficiency
(d) Genetically transmitted
A
- (a) Also called antibiotic sore mouth, it occurs primarily as a
sequela to prolonged course of broad spectrum antibiotics,
corticosteroids or immunosuppressant therapy. Lesions
in this type appear red rather than white, thus resembling
“thrush”.
27
Q
- Lesions of molluscum contagiosum occur primarily on
(a) Conjunctivae
(b) Skin and mucosae
(c) Sclera
(d) Scalp
A
- (b) The lesions of molluscum contagiosum occur only on
the skin and mucosae and are often tumor-like in nature
because of localized epithelial proliferation caused by the
poxvirus.
