Gram Positive Bacilli Part 2 Flashcards
1
Q
Most common location of spore in Clostridium species
A
Subterminal
2
Q
Terminal spores can be seen in which Clostridium species
A
C. Tetani
C. Tertium
3
Q
Central Spore can be seen in which Clostridium species
A
C. Bifermentans
4
Q
Shape of spores in C. Tetani and C. Tertium
A
C Tetani - Drum stick appearance (Round)
C Tertium - Tennis racket appearance (Oval)
5
Q
Mostly Clostridium species are uncapsulated except
A
C. Perfringes
C. Butyricum
6
Q
All Clostridium species are motile except
A
C Perfringes
C Tetani
7
Q
Clostridium perfringes Features
A
Non motile
Capsulated
Gram positive Bacilli
Subterminal spores
8
Q
Virulence factors of Clostridium perfringes
A
4 major toxin - alpha (lecithinase, phospholipase C), beta, epsilon, eeta
8 minor Toxin
9
Q
Clostridium perfringes associated with which infection
A
Wound infection - Simple wound Contamination, Anaerobic cellulitis, Anaerobic Myositis (Gas gangrene)
10
Q
Clostridium perfringes requires
A
Anaerobic environment
Contamination of wound
Rarely spontaneous
11
Q
Clostridium perfringes mechanism of action for gas gangrene
A
Lecithinase damage cell membranes - Capillary permeability increases - Tension in muscles - Further anoxia(Anaerobic environment)
12
Q
Clinical features of Gas gangrene
A
Pain
Discharge
Gas bubbles (Crepitus)
Shock
13
Q
Gas gangrene can be caused by
A
PSN
P - C. Perfringes (10-48 hours)
S - C. Septicum (2-3 days)
N - C. Novyi (5-6 days)
14
Q
Treatment of Gas gangrene
A
Surgical debridement
Iv penicillin + Clindamycin for 10-14 days
Hyperbaric Oxygen
Passive immunisation - Anti-gangrene serum
15
Q
Clinical features of Clostridium perfringes other than gas gangrene
A
Food poisioning (due to cold/warm up meat)
Gangrenous appendicitis
Necrotizing enteritis
16
Q
Specimen taken for C. Perfringes
A
Necrotic tissues
Muscle fragments
17
Q
Microscopic Findings for C. Perfringes
A
Subterminal spores
18
Q
Microscopic Finding for C. Septicum
A
Citron body
19
Q
Media used for C. Perfringes
A
Robertson Cooked meat broth (Red/Saccharolytic)
20
Q
C Perfringes other Diagnostic findings
A
Senior NTR
Senior - Stormy clot formation on litmus milk
N - Naegles Reaction - Nagler plate(Egg yolk medium) - Opaque area
T - Target hemolysis : Double zone of Hemolysis
R - Reverse CAMP Test +ve
21
Q
Spore seen in Clostridium Tetani
A
Terminal spore - Drum stick appearance
22
Q
Virulence factors of Clostridium Tetani
A
2 Exotoxins -
Tetanolysin(Hemolysin) - O2 Labile
Tetanospasmin - O2 labile
23
Q
Pathogenesis of C. Tetani
A
Spores in muscle - Release Tetanospasmin - Acts presynaptically at inhibitory neurons terminal - cleave VAMP-Synaptobrevin - inhibits release of GABA and Glycine - no relaxation of muscles - Muscle spasm
24
Q
Transmission of C. Tetani occurs by
A
Injury
Unsterile RTA
25
Incubation period of C Tetani
6-10 days
26
First symptom of C. Tetani
8th day disease
Increased tone of Masseter (Jaw lock/Trismus)
Risus Sardonicus (Sarcastic smile)
Opisthotonos
Limb spasm
Descending Spastic paralysis
Exaggerated DTR
Autonomic disturbances
M/C cause of death - Respiratory Failure
27
Specimen taken for C.Tetani
Necrotic tissue
28
Microscopic examination findings of C. Tetani
Gram +ve bacilli, Terminal spores (Drumstick appearance)
29
Blood agar finding for C. Tetani
Swarming on blood agar
30
Gelatin stab finding for C. Tetani
Fir tree appearance
31
C. Tetani finding on Robertson Cooked meat broth
Black color - Proteolytic reaction
32
Which technique used to obtain pure colonies of C. Tetani
Fildes Technique
33
Prevention after injury in Category A patient's
Category A - TT/Booster in last 5 years
Simple wound(Clean;<8hr) - Nothing
Other wound(Dirty;>8hr) - Nothing
34
Prevention after injury in Category B patients
Category B - 5-10 years
Simple wound : Toxoid 1 dose
Other wound - Toxoid 1 dose
35
Prevention after injury in Category C patients in C. Tetani
Category C - Beyond 10 years
Simple wound - Toxoid 1 dose
Other wound - Toxoid 1 dose + HTIg
36
Prevention after injury in Category D patients in C. Tetani
Category D - Unknown status
Simple wound - Complete Toxoid dose
Other wound - Complete Toxoid dose+ HTIg
37
Which infection is associated with Bottle and Canned food
Clostridium Botulinum
38
Virulence factors of C Botulinum
Botulinum toxin - Serotype A,B,E (A most severe) - all chromosomal mediated except C1,C2,D - phage coded
39
All Botulinum toxin are neurotoxin Except
C2 - Enterotoxin
40
Pathogenesis of C. Botulinum
Affects excitatory nerve terminals - toxin inhibits the Snare proteins - there is no fusion leading to inhibition of Ach release - No contraction - Floppy/Flaccidity
41
Types of Botulism
Foodborne Botulism
Wound Botulism
Infant Botulism
Iatrogenic Botulism
42
Incubation Period of Foodborne Botulism
12-36 hours
43
Clinical features of Foodborne Botulism
D's
Diplopia
Dysphagia
Dysarthria
Descending Flaccid paralysis
Dilated pupils
+ GI Symptoms
44
Incubation period of Wound Botulism
7-10 days
45
Infant Botulism Incubation period
1-2 days
46
Clinical features of Infant Botulism
First symptom - Constipation
Floppy baby Syndrome (Flaccid muscles)
47
Microscopic Diagnostic features of Infant Botulism
Gram Positive Bacillus
Spores - Subterminal, Oval, Bulging
48
Treatment of Infant Botulism
Toxoid antiserum
49
Clostridium defficille is known to cause
Pseudomembranous Enterocolitis
50
Virulence factor of C. Difficile
Toxin A - Enterotoxin (Attachment to gut)
Toxin B - Cytotoxin
51
Mechanism of action of Clostridium difficile
Toxin A and B - binds to Glucosylate GTP binding protiens - damage to actin. Cytoskeleton - Cell death
52
Colonoscopic findings in case of Pseudomembranous Enterocolitis
Dirty yellow Necrotic tissue towards mucosa
53
Microscopic Findings of C. Difficile
Volcano eruption
54
Most common risk factor of C. Difficile infection
Long term use of Antibiotics (3rd gen Cephalosporins)
55
Clinical features of Pseudomembranous Enterocolitis
Acute colitis with watery diarrhea, sometimes bloody
56
Media used for C. Difficile diagnosis
CCFA (Cefoxitin Cycloserine Fructose agar)
CCYA (Cefoxitin Cysteine yeast extract agar)
57
Treatment of Pseudomembranous Enterocolitis caused by C. Difficile
Earlier Oral Vancomycin - Now Fidoxamycin
For Fulminant CDI - Oral Vancomycin+ Iv Metronidazole and Rectal Vancomycin in enemas
58
Mycobacteria family includes
M. Tuberculosis
Non tuberculous Mycobacteria
M. Leprae
59
Mode of Transmission of M. Tb
Droplet (<5micron)
Ingestion
60
Antigenic properties of M. Tuberculosis
Mycolic acid - acid fastness
Cord factor - responsible for virulence
LAM (LipoArabinomannan)
61
Classification of Pulmonary TB
Primary Tb
Secondary Tb (reactivation)
Disseminated Tb
62
Primary Tb
Subpleural involvement
Lower part of upper lobe
Upper part of Lower lobe
63
Secondary Tb
Occurs at apex
Cavity present
64
Lung cavities are seen in which conditions
Secondary Tb
Histoplasmosis
Bronchiectasis
Squamous cell carcinoma
65
Pre existing lung cavity is seen in
Aspergillosis
66
Disseminated Tb
Due to hematogenous spread
Miliary Tb - Millet seeds
67
Foci seen when only lungs are involved
Ghon Foci
68
Foci when there is involvement of Lungs + Hilar lymph nodes
Ghon complex
69
Ghon complex + calcification is called
Ranke Complex
70
Focus called when Apex of lung is involved
Simon focus
71
Focus called when infraclavicular and supraclavicular parts are involved
SPA
Supraclavicular - Puhls Focus
Infraclavicular - Assman Focus
72
Tb Focus called when liver is also involved
Simmond Focus
73
Tb Focus called when Blood vessels are involved
Weigharts Focus
74
Tb Focus called when brain is involved
Rich's Focus
75
Most common Extrapulmonary Tb manifestation
Lymph node Tuberculosis
76
Extrapulmonary Tb findings
Kidney - Putty kidney
Urinary bladder - Thimble bladder
Skeletal - Spine - Pott's spine
Skin - Lupus vulgaris, Scrofuloderma
77
Specimen used for Tb diagnosis
Sputum - 2 sample - Spot sample and early morning sample
78
If sputum unavailable which specimens can be taken for diagnosis of Tb
Laryngeal aspirates
Bronchial secretions
Bronchoalveolar lavage
In children - Gastric lavage
79
For Diagnosis of Lymph node Tuberculosis
FNAC (Fine needle aspirate Cytology) - Pus
80
For diagnosis of Tb Meningitis
Cobweb reaction
81
In case of Pulmonary TB, Sputum is concentrated by which method
Petroff method (Sputum + 4% NaOH)
82
Stain used for diagnosis of M. Tb
ZN stain
Organism - Red
Background - Blue
83
Differentiation of Typical Mycobacteria with Atypical
M. Tb is both acid and alcohol fast
Atypical Tb is only Acid fast
84
Grading Of Tb
None - Negative - Negative
1-9/100field - Positive - Scanty
10-99/100field - Positive - 1+
1-10/field - Positive - 2+
>10field - Positive - 3+
85
Florescent stain used for M. Tb
Auramine, Rhodamine
Rapid and more sensitive
Recommended screening method
86
Egg based culture media used for diagnosis of M. Tb
Lawstein-Jensen media
87
Lawstein-Jensen media includes
Coagulated hen's egg
Mineral salt solution
Asparagine
Malachite green
88
Finding of M. TB on Lawstein-Jensen media
Rough Buff Tough colonies (takes 6-8 weeks to grow)
89
Blood based media used for M. Tb
Tharshi medium
90
Serum based media used for diagnosis of M Tb
Loeffler's medium
91
Potato based media used for diagnosis of M Tb
Pawlowsky medium
92
Liquid media used for diagnosis of M Tb
Middlebrooks
Sula and Sautons
Prausker and Becks
93
Finding on Liquid media for Tb
Long serpentine cords
94
Newer automated methods takes how much time to give result
8-14 days
95
Bactec MGIT uses
Middlebrooks 7H9 broth
Fluorometric technique
MGIT - Mycobacterial growth indicator tube
96
BacT test is based on
Calorimetry based
97
Versatrek method detects
Pressure changes in media due to gas production
98
How many fields need to see atleast before giving diagnosis of Tb negative
Atleast 100 field over 10 minutes before giving negative
10min/100fields/10000sensitvity
99
Typing Methods used for Diagnosis of Tb
RFLP (Restriction fragment length polymorphism)
Gene Xpert - Type of CBNAAT
Line probe assay
100
RFLP And it's disadvantage
Target sequence/strain
Can't differentiate active and latent Tb
101
Gene Xpert
Type of CBNAAT
Use - Diagnosis+ Rifampicin resistance
Turn around time - 2hrs
Sensitivity and specificity: 88% and 99% respectively
102
Methods used to diagnose Latent tb
Tuberculin/Mantoux test
IGRA (Interferon gamma release assay)
103
Antigen used for tuberculin Mantoux test
PPD (Purified protein derivative)
104
Site and method of administration in tuberculin Mantoux test
Intradermally injected in flexor aspect of Forearm
105
Reading of tuberculin Mantoux test is usually done after
72 hours
106
Positive tuberculin Mantoux test means
Width of induration should me 10mm or more
107
Tuberculin test will be negative if
Width of induration is less than 5mm
108
False positive tuberculin Mantoux test can be seen in cases of
BCG vaccination
No tuberculous bacteria
109
False negative tuberculin Mantoux test can be seen in
Early Tb
110
Advantage and disadvantages of IGRA
Negative in BCG vaccinated
But cannot differentiate between latent and active infection
111
MPT64 Test
Transdermal patch test
Only positive in case of Active Tb
100% specificity
112
Which method is good for Tb patients with HIV
LAM Assay (LipoArabinomannan)
Urine sample
Immunochromatographic testing
113
Prophylaxis of Tb, Vaccine dose and site of administration
BCG vaccine - Dose 0.1mL and injected above insertion of Left deltoid
114
Intravesical BCG can be used in treatment of
Superior Urinary bladder cancer
115
BCG vaccine provides immunity for how long
15-20 years
116
Features of Non tuberculosis Mycobacterium
All are Catalase +ve
Reservoir - Soil, H20
No human to human
Acid fast
But not alcohol fast
117
Non tuberculosis Mycobacterium also known as
Environmental bacteria or Tuberculoid Mycobacteria
118
Which classification is done to classify Non tuberculosis Mycobacterium
Runyon's classification
119
Types of Non tuberculosis Mycobacterium according to Runyon's classification
Photochromogens
Scotochromogens
Non - photochromogens
Rapid growers
120
Photochromogens
Pigment production only in Light
MASK
M. marineum
M. Asiaticum
M. Sinniae
M. kansassi
121
Scotochromogens
Pigment production in light+ dark
God Save us from Dark
M. Szulgai
M. Scrofulaceum
M. Gordonae
122
M marineum causes
Swimming pool/Fish tank granuloma - Warty skin lesions
123
M. Kansassi is known to cause
Upper lobe scarring/cavity formation
124
Tap water scotochromogens is
M. Gordonae
125
Non photochromogens
M. Avium
M. Interacellulare
M ulcerans
M xenopi
126
Most common cause of Granulomatous disease
M. Avium
127
Mycobacteria avium complex is formed by
M. Avium + M. Interacellulare - MA
128
Mycobacteria Avium Complex is associated with which syndrome
Lady Windermere's Syndrome
129
M. Interacellulare also known as
Battery bacillus
130
M. Ulcerans is known to cause
Brucelli ulcer
131
Mycobacteria Indicus Pranii
It is an immunomodulator
Vaccine for leprosy (MW vaccine)
132
Rapid growers includes
M fortuitum
M. Smagmatis
M. Chelonae - result of post surgery abscess
M.phlei
133
Mycobacteria Leprae is also known as
Hansen's Bacillus
134
Mycobacteria leprae Features and Mode of transmission
Obligate intracellular
Obligate aerobe
Mode of transmission - Nasal droplet > Contact > breast milk
135
Classification used to classify Mycobacterium leprae
Ridley Jopling Classification
136
Ridley Jopling Classification of Mycobacteria Leprae
LL - Lepromatous leprosy
BL - Borderline Lepromatous
BB - Borderline Leprosy
BT - Borderline Tuberculoid
TT - Tuberculoid leprosy
137
Bacillary load in Lepromatous leprosy and Tuberculoid leprosy
LL - Multibacillary
TT - Paucibacillary
138
Skin lesions seen in Lepromatous leprosy and Tuberculoid leprosy
LL - Leonine facies with alopecia
TT - few lesions
139
Nerve lesions in TT AND LL
LL - late nerve lesions
TT - Early nerve lesions
140
Lepromin test in LL AND TT
LL - negative
TT - positive
141
Humoral immunity is increased in LL OR TL
Lepromatous leprosy
142
Macrophages and giant cells are seen in which leprosy
Tuberculoid leprosy
143
How many Samples taken for diagnosis of Leprosy
6 smear samples - 4 Skin (Forehead, cheek, chin, buttock)
Ear lobe
Nasal mucosa
144
Stain used for diagnosis of Leprosy
ZN stain 5% H2SO4 - Fite Forocco stain
145
Microscopic Findings of Leprosy
Virchow cells (Macrophage) - seen in Lepromatous leprosy
146
Grading of M. Leprae
1-10 bacilli/100 fields - 1+
1-10 bacilli/10 fields - 2+
1-10 bacilli/field - 3+
10-100 bacilli/field - 4+
100-1000 bacilli/field - 5+
>1000 bacilli/clumps/Globi in every field - 6+
147
Culture of M. Leprae
Non cultivable (Obligate intracellular)
148
Serological finding of M. Leprae
Antibody against PGL-1 (phenolic glycolipid)
149
Lepromin test
0.1 ml Lepromin antigen - given intradermally in forearm
150
Interpretation of Lepromin test
Fernandez reaction (Early) - >10mm induration after 48hrs
Mitsuda reaction (late) - >5mm nodule at 21 days or 3 weeks
151
Treatment of Leprosy
DCR
Dapsone
Clofazimine
Rifampicin
For 6-12 months
152
Lepromin test is based on which hypersensitivity reaction
Type 4 HS
153
Lepra reaction is classified into
Type 1
Type 2
154
Type 1 and Type 2 Leprae reaction shows which hypersensitivity reactions
Type 1 - Type 4 HS
Type 2 - Type 3 HS.
155
Type 1 Leprae reaction is usually seen in
Borderline Leprosy
Downgrading - LL
Reversal /upgrading - TT
can be seen before or after treatment
156
Erythema nodosum leprosum seen in which Leprae reaction
Type 2 - TYPE 3 HS
157
Type 2 lepra reaction is seen in
Borderline Lepromatous and Lepromatous leprosy
Seen after treatment
158
Clinical features of Type 1 leprae reaction
Edema
Ulnar nerve involvement
159
Type 2 Leprae reaction clinical features
Crops of tender inflamed nodules (due to interferon alpha) - Erythema nodosum leprosum
160
Which helper cells associated with Type 1 and Type 2 leprae reaction
Type 1 - Th1 response
Type 2 - Th2 response
161
Which sign is positive in Type 1 leprae reaction
Tinel sign - pressure exerted on nerve causes tingling sensation
162
Treatment of Type 1 and Type 2 Leprae reaction
Type 1 - Glucocorticoids
Type 2 - Thalidomide
163
Type 2 leprae reaction mnemonic
TTTTTT
Type 2
Treatment associated
Tender nodules (ENL)
TNF alpha
TH2
Thalidomide
164
How Mycobacteria tuberculosis is differentiated from other Mycobacteria
Niacin +
Nitrate reduction+
Catalase +
Colonies - Rough buff Tough colonies
