د.الهام Bacteria Flashcards
(159 cards)
1
Q
The staphylococci are gram- positive spherical cells, usually arranged in …..
They grow readily on many types of media and are active metabolically, …… and producing …… that vary from white to deep yellow (golden) as a result of …..during growth.
.
A
grape-like irregular clusters,
fermenting carbohydrates
pigments
carotenoid pigment
2
Q
Some of staphylococci are members of the …. of the skin and mucous membranes; others are …., causing …..
A
Normal flora
pathogenic
suppuration, abscess formation, a variety of pyogenic infection and even fatal septicemia.
3
Q
Staphylococcus aureus
A
Non-motile, no spore forming, facultative anaerobic
Catalase positive.
Hardy organisms surviving many non-physiologic conditions.
*Hemolysis blood, coagulates plasma, and produces a variety of extracellular enzymes and toxins.
Rapidly develop resistance to many antimicrobial agents.
4
Q
. …. is carries by 20-50% of healthy individuals on nasal mucosa & on the skin.
A
S.aureu
5
Q
CLASSIFICATION of staphylococcus
A
Based on coagulase production:
1. Coagulase positive: (e.g. S.aureus)
2. Coagulase negative :( e.g. S. epidermidis) & (S. saprophyticus).
B) Based on pathogenicity:
1. Common pathogen :( e.g.-S. aureus)
2. Opportunistic pathogens: (e.g.-S. epidermidis)
(S.saprophyticus)
6
Q
Virulence factors & diseases of staphylococcus
A
Cell associated factors
1Capsule: slim layer of polysaccharide protect bacteria from PMN leukocytic phagocytosis.
2Cell wall: rigid peptidoglycan layers, stimulates the production of endogenous pyrogens, IL-1 &PMN activate (abscess formation).
3Protein A: linked to cell wall, preventing the antibody mediating immune clearance and complement consumption.
4Teichoic acid: linked to the peptidoglycan & can be antigenic, it’s also mediating the attachment of staphylococci on mucosal surfaces.
EXTRACELLULAR FACTORS
A Enzymes:
1Catalase; convert H2O2→H2O +O2.
(The catalase test differentiate staphylococci (+ve catalase) from other strain (-ve catalase streptococci).
2Coagulase; Convert fibrinogen→ insoluble fibrin.
3Hyaluronidase ; hydrolyze hyaluronic acid that found in cellular matrix of the connective tissues.
3 Lipase; hydrolyze lipid to ensure the staph survival in sebaceous area of the body.
4Other enzymes which have role in diseases such as kinase nuclease and pinicillinase.
B Toxins:
Exotoxins
1. Cytolytic toxins
i) Hemolysins
Alpha hemolysin; potent hemolysis toxin.
Beta hemolysin; degrades sphingomyelin & therefore is toxic for many kinds of cells.
Gamma hemolysin; lyse erythrocytes from humans & animals.
Delta hemolysin; disrupt biologic membrane.
ii) Leukocidin; toxin, kill human leukocytes.
2Exfolitative toxin, (epidermolytic toxin), causing staphylococcal scalded skin syndrome (SSSS).
3) Toxic shock syndrome toxin- 1 (TSST-1),
Superantigen binds to MHC class II molecules,T cell stimulation.
Also associated with fever, multisystem involvement shock & desquamated skin rash.
4Enterotoxins: Five serologically toxins (A-E) which are superantigens, an important cause of food poisoning.
7
Q
Pathogenicity: of staphylococcus
The pathogenic capacity of staphylococcus species is combined effect of extracellular factors and toxins together with the invasive properties of the strain in the host tissue.
A
8
Q
Staphylococcus infections
Local lesions of skin:
….. (is inflammation at the base of the eyelashes, The first sign of a stye is a small, yellowish spot),
….. (infection of hair follicle resulting in localized accumulation of pus and dead tissue often on back or neck), …. (infection of several hair follicles), …… (progressive appearance of swelling and pain in a surgical wound after about 2 days from the surgery).
…. (skin lesion with blisters that break and become covered with crusting exudate).
Systemic infections (endocarditis, osteomyelitis &septic arthritis.
A
Styes
Furuncles or Boils
Carbuncles
Woundinfections
Impetigo
9
Q
Staphylococcal food poisoning:
A
Enterotoxin is responsible for manifestations of staphylococcal food poisoning.
Five types of enterotoxin are currently known, named A, B, C, D and E.
It usually occurs when preformed toxin is ingested with contaminated food
The toxin acts directly on the autonomic nervous system to cause the illness, rather than gut mucosa.
The common food items responsible are - milk and milk products, meat, fish and ice cream.
Source of infection- food handler who is a carrier.
Incubation period- 2 to 6 hours.
Clinical symptoms- fever, nausea, vomiting and watery diarrhea.
The illness is usually self-limited, with recovery in days.
10
Q
- Staphylococcal Toxic shock syndrome (STSS):
A
The disease initiated with localized growth of toxin-producing S.aureus in vagina or a wound.
It is fatal multisystem disease presenting with fever, hypotension, myalgia, vomiting, diarrhea, mucosal hyperemia and erythematous rash which desquamates subsequently.
Types of STSS known:
Menstrual associated STSS: Here colonization of S.aureus occurs in the vagina of menstruating woman who uses highly absorbent vaginal tampons.
Non menstrual associated STSS: Here colonization of S. aureus occurs in other sites like surgical wound.
11
Q
Staphylococcal scalded skin syndrome (SSSS):
A
-Exfoliative toxin produced by S.aureus is responsible for this.Also known as Ritter’s disease.
-It is a skin disease in which outer layer of epidermis gets separated from the underlying tissues.
-Disease of young children.
-Mediated through minor Staphylococcal infection by epidermolytic toxin’ producing strains
-Mild erythema (redness and inflammation around the mouth) and blistering of skin followed by desquamation of epidermis.
-Bullous impetigo (superficial infection affecting mostly young children, on face and limbs) is a localized form of SSSS.
-Children are otherwise healthy and most eventually recover as a result of antibodies formation.
12
Q
Staphylococcus culture
A
Culturing in blood(β- hemolytic) and Mannitol agar.
13
Q
.. is the antibiotic of choice in the treatment of staphylococcal diseases.
A
Vancomycin
14
Q
Stapylococcus saprophyticus:
.
A
Skin commensal.
.Important Cause of UTI in sexually active young women.
.Infected women have dysuria (pain in urination) &pyuria(pus in urine).
.Usually sensitive to wide range of antibiotic.
15
Q
Staphylococcus epidermidis:
..
A
Coagulase negative staphylococci.
.Skin commensal.
.Has predilection for plastic material.
.Associated with infection of IV lines, prosthetic heart valves, shunts.
.Causes urinary tract infection in catheterized patients
.Has variable ABS pattern
16
Q
.Important Cause of UTI in sexually active young women.
.
A
Stapylococcus saprophyticus:
17
Q
Aerobic non-spore forming bacilli:
A
Corynebacterium diphtheriae.
Listeria monocytogenes.
18
Q
spore- forming bacilli:
A
Bacillus anthracis (Aerobic).
Clostridium species (Anaerobic).
19
Q
Corynebacterium diphtheria
Is a Gram-positive rod, 0.5-1µm in diameter.
Arranged as ….
The cells are …. , often with …
They also contain ….. that stain differently from the other cell materials.
A
irregular aggregations looking like (Chinese letters).
pleomorphic
bulging at one end that gives a club appearance (Greek coryne= club)
accumulations of phosphates (metachromatic granules)
20
Q
Corynebacteria normally colonize the ….
The most virulence strain is …
Greek, diphtheriae ‟ leathery skin” referring to the ….
A
skin, upper respiratory tract, gastrointestinal tract, and urogenital tract of human.
C. diphteriae .
pseudomembrane that initially forms on the pharynx.
21
Q
Corynebacterium diphtheria
This disease results when the organism produces a …… that absorbed by various tissues within the body.
The toxin acts by …..
A
powerful exotoxin
inhibiting the translation step during eukaryotic protein synthesis.
22
Q
1-Corynebacterium diphtheria
The ability to produce the exotoxin is associated with infection of bacterium with ….
A
bacteriophage
23
Q
lysogenic activation
A
The ability of bacteriophage to insert their DNA into bacterium DNA
24
Q
Corynebacterium diphtheria
However, not all strains are . …
.
A non-toxigenic strain can become toxigenic by the infection of such a ….
A
toxigenic
bacteriophage
25
Diphtheria It is transmitted from .... by .... especially in ..
person to person
respiratory droplets or skin contact,
crowded and unsanitary living conditions.
26
Diphtheria is primarily a .... disease, caused death among children.
childhood
27
Today diphtheria is rare due to ....
widespread vaccination
28
The clinical presentation of diphtheria is determined by the
site of infection, the immune status, and the virulence of the organism.
29
Respiratory diphtheria:
The symptoms develop after...
Organisms multiply ...
Onset malaise, sore throat, exudative pharyngitis and low grade fever.
The exudate evolves into ....
This membrane (marker of diphtheria) covers the ...
2-6 days incubation period.
locally on epithelial cells in the pharynx and initially cause localized damage as a result of exotoxin activity.
thick, gray pseudomembrane (composed of bacteria, lymphocytes, plasma cells, fibrin, and dead cells).
tonsils and extends up into the nasopharynx or down into the larynx causing breathing difficulties and painful swallowing.
30
marker of diphtheria)
thick, gray pseudomembrane
31
Respiratory diphtheria
Swollen lymph nodes of neck causing ....
Complications in patients with severe disease include ...
bull neck appearance.
breathing obstruction, cardiac arrhythmia and coma.
32
Clinical picture of Respiratory diphtheria
Bull neck diphtheria pseudomembrane
33
Cutaneous diphtheria
The organism colonizes the ...
... is first develop and then evolves into a ... covered with a ..
skin and gain entry into subcutaneous tissue through breaks in the skin.
A papule
chronic ulcer
grayish membrane.
34
Cultivation on ... (selective differential medium for C.diphtheriae) , which grow and give ... appearance.
cultivation on ..which give. gray to black colonies.
Loffler's serum
poached egg
Tellurite medium
35
Laboratory diagnosis: diphtheria
Toxigenicity test to detect exotoxin production:
This can be done by an in vitro .. using .specific antitoxin .
In vivo, using ... injected subcutaneously.
immunodiffusion assay (Elek test),
guinea pigs
36
Symptomatic diphtheria can be prevented by .... and with ...
Initially, children are given monthly injections of ...
actively immunizing people with diphtheria toxoid during childhood
booster doses every 10 years throughout life.
diphtheria toxoid, pertussis and tetanus antigen (DPT) vaccine.
37
Listeria
......
The organisms are .....
Small, gram- positive, non-spore forming, facultative anaerobic bacillus.
motile at room temperature with tumbling motion by means of 4 flagella.
38
Listeria organisms are widely distributed in nature, but the more susceptible people to listeria diseases are .....
neonates, elderly, pregnant women and immunocompromised patients.
39
Listeria causing .....
meningitis and bacteremia.
40
L . monocytogenes is a facultative intracellular pathogen, can grow in ..
macrophages, epithelial cells.
41
Listeria monocytogenes
The virulent strain produce: .....
Hemolysin, which help the bacteria to released after phagocytosis and intracellular growth.
Listeriolysin O; which are genetically related to streptolysin O and pneumolysin , degrade the cell membrane.
42
Virulence factor of listeria monocytogenes
Hemolysin
Listeriolysin O
43
Human listeriosis is a ... disease seen throughout the year, especially in the warmer months.
The disease is ....., associated with .....
This organism can grow in ...... Thus it can multiplication in ....
sporadic
foodborne
consumption of contaminated milk, soft cheese, undercooked meat, unwashed raw vegetables .
a wide PH ranges and in cold temperatures
refrigerated contaminated food.
44
Neonatal disease
Surviving neonates of fetomaternal listeriosis may suffer ..... unless it is promptly treated.
.......... occurs 2-3 weeks after birth.
granulomatosis infantiseptica — pyogenic granulomas distributed over the whole body
Meningitis or meningoencephalitis with septicemia
45
Adult diseases:
Manifestation of adult listeriosis especially in immunocompromized adult with renal transplantation includes .....
Infections in pregnant women may lead to ....
meningitis, septicemia, endocarditis, and corneal ulcer.
abortion or premature delivery and the infected mothers has an influenza-like illness.
46
Cultivation of listeria on ...
blood media ( small, gray, β hemolytic colonies).
47
Listeria Invasive disease is treated by a combined therapy of
ampicillin and gentamicin
48
Bacillus anthracis
Gram positive rod, normally resides as ...
spores in the soil.
49
B. anthracis possesses an antigenic ......
Anthrax are different diseases caused by B. anthracis and is Greek means .....
unique capsule composed of D- glutamic acid (retards phagocytosis by host cells).
coal
50
Transmission of anthrax among animals (. ......) usually through .....
It infects humans upon contact .....
Exposure to spores and infected with them through a .....
No spread from one person to another.
sheep, horse, and cattle
ingestion of spore-contaminated feed.
with infected animals.
skin wound, ingestion, or by inhalation.
51
PATHOGENESIS of B. anthracis
B. anthracis possesses a capsule that is antiphagocytic and is essential for full virulence.
The organism also produces three plasmid-coded exotoxins:
Edema factor.
Protective antigen(PA).
( both a and b responsible for the severe edema usually seen in B. anthracis infections)
Lethal toxin is responsible for tissue necrosis.
52
: the most common form of anthrax
Cutaneous anthrax
53
Clinical picture of Cutaneous anthrax
eschar
54
Cutaneous anthrax: the most common form (95%), causes..... , results when the spores enters the tissues through abrasions or lesions.
a localized, inflammatory, black, necrotic lesion (eschar)
55
Pulmonary anthrax: the highly fatal form, is characterized by ...'..
sudden, fever, pneumonia , massive chest edema followed by cardiovascular shock.
56
Gastrointestinal anthrax: a rare but also fatal (causes .....
death to 25%) type, severe enteritis results from ingestion of spores.
57
B. anthracis Cultured on ... to confirm the presence of bacteria.
nutrient agar and blood agar
Cloudy appearance
58
B. anthracis
Several antibiotics are effective including ....
... are available to control the disease in animals and humans.
penicillin, doxycycline and ciprofloxacin.
Vaccines
59
Bacillus cereus
Morphologically .... to B. anthracis
It is present in .......
It produces ..... that cause ......
Food poisoning results from the ingestion of preformed enterotoxins, producing .....
similar
soil, contaminating agricultural products
enterotoxins
food poisoning.
vomiting and diarrhea.
60
Type of Bacillus cereus enterotoxin
heat stable toxin
heat labile toxin
61
The vomiting form:
Is most often associated with ...... from .....
This toxin is similar to ...
The symptoms include ....
ingestion of heat stable toxin
contaminated rice.
S. aureus toxin.
vomiting, nausea, abdominal pain beings after 2 hr of ingestion.
62
The diarrheal form:
Is most associated with ......
.....occurs within 9 hr of ingestion.
Treatment in both forms is ...
ingestion of heat labile toxin in contaminated meat, sausage or vegetables.
Watery, non-bloody diarrhea
only symptomatic.
63
Aerobic spore forming bacilli
1) - Bacillus anthracis
- Bacillus cereus
64
Anaerobic spore forming bacilli
Clostridium species
65
Clostridium species
From the Greek .. or.. due to its rod-shaped cells.
Are ....
Most species of the genus Clostridium are ... found in many places in the environment, most notably the soil.
Also are parts of normal ...
Clostridia associated with ...
kloster
spindle
Gram-positive, anaerobic, spore forming and toxin producing rods.
saprophytic organisms
microbiota in the gastrointestinal tract.
skin and soft tissue infections, food poisoning, and colitis.
66
Clostridium species
The ability of causing disease as a result of numerous toxin productions(...
histolytic toxins, enterotoxins and neurotoxin
67
Clostridium perfringens ( C. perfringens)
..........
It founds in .....
Its presence in water indicates its fecal pollution.
The organism grows .....
Gram-positive, capsulated, spore forming and non-motile rods.
large intestine of man and animal, in soil and dust.
rapidly in tissues and in lab culture.
68
Pathogenesis and immunity:
C. perfringens can cause spectrum of disease from .....
It produces major lethal toxins which use to subdivided organism into five types ( A-E):....
self- limited gastroenteritis to severe tissue destruction.
α toxin, produced by type A and has lytic activity to erythrocytes, leukocytes, platelets and endothelial cells.it associated with massive hemolysis and bleeding, tissue destruction (myonecrosis) or gas gangrene and myocardial dysfunction.
β toxin ,produced by type B & C, responsible for causing the necrotic lesions in necrotizing enteritis .
Epsilon toxin is a protoxin increases the vascular permeability of the gastrointestinal wall.
Iota toxin, other lethal toxin, and has necrotic activity.
Enterotoxin is a heat-labile protein, produced by type A and a few types C, D strains and causes food poisoning.
69
Clinical picture of c.perfringens
Myonecrosis ( gas gangrene
Cellulitis and fasciitis
3) - Food poisoning
70
Myonecrosis ( gas gangrene):
Is a life-threating disease.
The toxin involved in gas gangrene is α-toxin, which inserts into the plasma membrane of cells, producing gaps in the membrane that disrupt normal cellular function.
After clostridia introduced into tissue by trauma or surgery, intense pain generally develops within 1 weeks.
Followed rapidly by extensive muscle necrosis, shock, renal failure and death.
71
Cellulitis and fasciitis:
Clostridia species can colonize....
It can cause cellulitis (....
It can cause fasciitis (.....
wounds and skin with no clinical consequences.
bacterial infection involving dermis and subcutaneous fat of the skin) .
an inflammation of the fascia, which is the connective tissue surrounding muscles, blood vessels and nerves).
72
Food poisoning:
It is characterized by .....
.... clinical presentation.
Diseases results from the .....
Enterotoxin is responsible for this disease.
The refrigeration of food after preparation prevents enterotoxin production.
short incubation period (8-24 hr).
Abdominal cramps and watery diarrhea are
ingestion of contaminated meat.
73
Anaerobic cultivation of c.perfringens on:
Blood agar media(β hemolytic zone).
Cooked meat media (blacking of meat with H2S production).
Litmus milk (produces stormy clot).
74
Nagler’s reaction,
for the identification of alpha toxin of Clostridium perfringens (the addition of antitoxin to cultures on egg yolk agar prevents visible opacity, due to lecithinase action which is normally observed around colonies).
75
- Clostridium tetani (C. tetani)
Pathogenesis and disease:
C. tetani wide distributed in nature, commonly in ....., so the wounds are often contaminated with tetani spores.
The disease caused is known as .......(because the patient’s inability to open the mouth as a result of .....
The disease as a result of potent toxin production termed as ........which is a .......
The C. tetani grow locally in necrotic tissue and produce ......
soils and manures
tetanus or lockjaw
muscle paralysis).
Tetanospasmin toxin),
neurotoxin responsible for tetanus symptoms.
tetanospasmin toxin that transport through the axon of nerves to CNS causing spastic paralysis.
76
Clinical picture and sign of c.tetani
Lockjaw opisthotonos
risus sardonicus
77
Laboratory diagnosis:
Tetanus diagnosis is based on ....
physical examination of the patients (signs of muscles spasms, stiffness and pain).
78
Clostridium botulinum ( C. botulinum)
C. botulinum (Lat. botulus, “sausage”).
The organisms are subdivided into ...... on the basis of the type of toxin produced and their
Most human diseases are caused by types ....
These toxins are neurotoxin similar in structure and function to tetanus toxin, but differing only in the .....
This toxin is specific for ...s.
four groups( I-IV
proteolytic activity.
I and II strains.
target neural cell.
cholinergic nerves (blocks neurotransmitter acetylcholine ) , causing symmetrical flaccid paralysis
79
Three forms of botulism have identified:
Foodborne botulism
Infant botulism
Wound botulism
80
Foodborne botulism:
Is caused by ......., this typically occurs in home-canned food substances and fermented uncooked dishes.
Initial signs include ....
......... are progression form of the disease leading to death.
Intensive care particularly in the management of respiratory complication reduce mortality rate.
eating foods contaminated with bacteria toxin
blurred vision with fixed dilated pupils, dry mouth, constipation and abdominal pain.
Flaccid paralysis and respiratory complication
81
Infant botulism:
It results from organisms colonizing ..... and release the toxin.
Infant botulism results from the .....
The infant gut may be colonized when the composition of the intestinal microflora is insufficient to competitively inhibit the growth of C. botulinum .
.... caused by botulism.
the infant’s intestinal tract (younger than 1 year)
ingestion of the C. botulinum spores, and subsequent colonization of the small intestine.
Constipation, weak cry and difficulty in swallowing.
Sudden infant death syndrome (SIDS)
82
The primary treatment of botulism is with an .... and supportive care.
antitoxin (human botulinum immunoglobulin)
83
Actinomycetes
There are . ..... that tend to form chains or filaments.
.... positive.
Most are saprophytic in soil.
Pathogenic members are responsible for human .... disease .
Gram-positive bacilli
Catalase
actinomycosis
84
Actinomycosis :
It is a chronic infection produced by ..... that normally colonize ....
opportunistic organism Actinomyces israelii
the mouth, upper respiratory tract, gastrointestinal tract and female genital tract.
85
Actinomycosis
The organism grows in anaerobic niche forming multiple abscesses connected by sinus tracts (contain microscopic colonies of organism termed as ... ).
sulphur granules
86
Actinomycosis
Sulphur granules are .....
masses of filamentous organisms bound together by calcium phosphate
87
Actinomycosis
The organism may also cause .......are the most common triggering events .
Infection varies between .......
..... is uncommon in this form of the disease).
It cause .... (which is often misdiagnosed as a ...., as it forms a mass that extends to the chest wall.
It arises from aspiration of organisms from the oropharynx
Symptoms include ....
Also affect abdominal, pelvic or affecting the central nervous system.
endocarditis, dental caries, and oromaxillofacial traumas ( disfigurement and loss of function)
cervicofacial ((painful "lumpy jaw").
Lymphadenopathy
thoracic disease
neoplasm
chest pain, fever, and weight loss.
88
Actinomycetes
The organism is facultative anaerobe; cultured on ....
It is .... growing
thioglycolate broth or brain heart infusion blood agar under anaerobic codition.
slowly
89
Nocardia
Gram-positive, catalase-positive, rod-shaped bacteria
It forms partially acid-fast beaded branching filaments.
90
Nocardia
They are oral microflora found in ..
healthy gingiva.
91
Most Nocardia infections are acquired by ..
inhalation of the bacteria or through traumatic introduction.
92
Nocardia
strict .. with the ability to grow in a ....
Nocardia .... is most frequently found species infecting humans.
Most cases occur as an ..
aerobes
wide temperature range.
asteroides
opportunistic infection in immunocompromised patients
93
Clinical picture of Nocardia
pneumonia
Endocarditis
encephalitis and/or brain abscess formation.
actinomycetoma ( a chronic subcutaneous infection
94
Nocardia
Slowly progressive ....( the common symptoms of which include ...
pneumonia
cough, dyspnea (shortness of breath), and fever).
95
.. as one of its main pathogenic effects.of Nocardia
Endocarditis
96
In about 25–33% of people Nocardia infection takes the form of ...
encephalitis and/or brain abscess formation.
97
Nocardia may also cause a variety of cutaneous infections such as .... that affect the skin and connective tissue) , and subcutaneous abscesses.
actinomycetoma ( a chronic subcutaneous infection
98
Campaylobacter
Small, .... shaped, Gram-negative rods.
Motile
Most species are .... (decreased O2 & increased CO2).
.... (optimum temperature is 42oC)
Nonsporing
.... positive.
Unable to ferment ....
comma
microaerobic
Thermophilic
Oxidase
carbohydrates
99
Campylobactr .... & campylobacter ... are common human pathogens.
.These two types causing mainly....
They also cause Extra intestinal infection: ...
jejuni
coli
enteritis(campylobacteriosis).
Bacteraemia.
Reactive arthritis.
Guillain –Barre syndrome (GBS).
100
Campaylobacter
Epidemiology:
.... such as cattle, chickens & dogs which carry the organism in their .......
Infection is acquired by...
Domestic animals
intestinal tract ( zoonotic disease)
Ingestion of contaminated food
drinks
Contact with infected animals.
101
Campaylobacter
Pathogenesis & virulence factors:
The organism multiply in ...., invade and destroy ...
It produce inflammation result in ....
Mucosal invasion coupled with the toxic activity .
Toxins include ...
The blood stream may invaded ( bacteremia) .
small intestine
epithelial cells in the jejunum, ileum and colon.
enteritis with RBCs & WBCs in stool.
endotoxic activity & enterotoxins .
102
Clinical picture of Campaylobacter
Incubation period is
It begins with acute onset of ....followed by ...
The illness is ... within few days.
1-7 days.
severe abdominal pain, profuse watery diarrhea
blood in stool .
Fever , malaise and headache.
self-limited
103
Complications of Campaylobacter
Aseptic arthritis it affects ankles, knees and wrists.
Guillian-barre syndrome:
104
Guillian-barre syndrome:
Is a form of peripheral polyneuropathy.
May cause serious paralysis.
Is an autoimmune disease due to production of antibodies against campylobacter that cross –react with the myelin in nerve sheaths, producing demyelination.
105
Campaylobacter
culturing in selective media as ...., and incubated in microaerophilic conditions.
oxidase positive.
Catalase positive .
No sugar utilization.
No urease producion.
Skirrows medium ( blood agar containing vancomycin, polymyxin B & trimethoprim to inhibit growth of other bacteria)
106
Helicobacter
Gram-negative; . ... (spiral or curved) bacteria.
Tuft (....) sheathed flagella attached at one pole
Microaerophilic
It is associated with ....
Helical
lophotrichous
acute gastritis, duodenal ulcer, gastric ulcer and gastric carcinoma.
107
Helicobacter pylori
..... is the main reservoir.
The human stomach
108
Helicobacter
Transmission of infection by ...
person to person contact (typically fecal-oral).
109
virulence factors of Helicobacter pylori
Active motility by the flagella
protease enzymes ( mucinase & phospholipase )
urease Enzymes
vacuolating cytotoxin
110
Pathogenesis and virulence factors of Helicobacter pylori
Active motility by the flagella enables the organisms to penetrate gastric mucosa.
H. pylori colonize only gastric epithelia but not intestinal epithelia.
The organism produce protease enzymes ( mucinase & phospholipase ) that disrupts gastric mucus, causing chronic inflammation of mucosa.
It also produce powerful urease enzyme that cleaves urea, producing ammonia (NH₃) that neutralizes stomach acid.
It produce vacuolating cytotoxin which cause gastric mucosa damaging , leading to expose the underlying connective tissues to stomach acid , causing gastritis and peptic ulcer.
111
Diseases associated with H.pylori:
Peptic ulcer disease
Gastric mucosa associated lymphoid tissue lymphoma (MALT); is a form of lymphoma involving the mucosa-associated lymphoid tissue frequently of the stomach.
Gastroesophageal reflux.
Gastric cancer.
112
Rapid urease test:
A piece of gastric biopsy is placed in urea broth with indicator that detect alkalinity resulting from the formation of ammonia by urease.
113
A)-urea breath test:
A capsule of urea labeled with an isotope of carbon is ingested by the patient.
If the H. pylori are present in the patients stomach , the urease will split the ingested urea into CO₂ (radio-labeled) which detected by radioactivity and NH₃.
114
H.pylori diagnosis
Cultivation on selective media containing...
5-10% horse blood supplemented with antimicrobials , incubated on microerophilic condition.
115
Smallest ( 150-250nm) free-living bacteria.
Mycoplasma
116
They passed through filters ...
They are unique among bacteria because they ...
They have ... in their cell membrane.
The absence of the cell wall renders the mycoplasmas ... that interfere with cell wall synthesis.
They are...
Poorlyly staining with .... but well staining with ...
impermeable to bacteria.
lack cell wall.
sterols
resistant to antibiotics
pleomorphic
Gram stain
Giemsaʹ s stain.
117
The important human pathogen is: of Mycoplasma
M. pneumoniae.
M. hominis.
M.genetilium.
Ureaplasma urealyticum.
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Mycoplasm pneumoniae
... human pathogen.
...aerobe.
Transmitted from person to person via .., causing ...
The more population affected is ...
It has ... serotype.
There is no ...
Strict
Strict
respiratory droplet
atypical pneumonia.
young adult( 5-15 ) years old.
only one
antigenic variation among strains.
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Pathogenicity & Virulence factors: of Mycoplasma pneumoniae
In the lung , the organism is rod shaped.
It adhere to respiratory epithelium by specialized adhesin protein (P1) .
P1 interacts with base of cilia on the epithelial cell surface causing ciliated epithelial cell damage.
The loss of these cells interferes with the normal clearance of the upper airway.
The lower respiratory tract become contaminated.
M. pneumonia functions as superantigens , stimulating inflammatory cells to produce cytokines, IL-1 and necrotic factor causing epithelial necrosis.
120
Virulence factors: of Mycoplasma pneumoniae
P1 interacts with base of cilia on the epithelial cell surface causing ciliated epithelial cell damage.
121
M. pneumonia functions as ...
superantigens , stimulating inflammatory cells to produce cytokines, IL-1 and necrotic factor causing epithelial necrosis.
122
Clinical diseases: of Mycoplasma pneumoniae
It causes ...
Patient present with symptoms of ...
Extrapulmonary manifestations include affection of ...
atypical pneumonia .
pneumonia , tracheobronchitis, pharyngitis or otitis media.
joints, skin, CNS, liver , myocardium and hemolytic anemia.
123
Mycoplasma
on special media contain ....to inhibit other bacteria.
The organism grow slowly
The colonies have characteristic ...
serum ( provides sterols), yeast extract, glucose and penicillin
fried egg appearance.
124
Mycoplasma pneumoniae
Detect of non-specific antibodies by
Cold agglutination( IgM antibodies that agglutinates O on the surface of human R. B.Cs at 4°C ).
125
M. hominis, M. genitalium & U.urealyticum
Found in
Infants are often colonized at ...
Adult are infected via sexual transmission.
urogenital tract of asymptomatic individuals.
birth via vaginal tract.
126
Clinical picture:
M. hominis is involved in
U. urealyticum & M. genitalium are involved in
nongoncoccal urethritis, pelvic inflammatory disease in females and pyelonephritis.
nongonococcal urethritis in males , premature rupture of membranes in pregnant
127
VIBRIOS
Rigid , Gram-.......shaped bacteria.
Highly .... with single polar flagella.
Non-spore forming.
.... anaerobic.
Their growth stimulated by .....
Tolerate a wide range of PH (6.4- 9.6).
Growth temperature between (16-40°c ).
Vibrios are present in ...
negative curved or comma
motile
Facultative
Nacl ((Halophilic)).
aquatic environment .
128
The more clinically important vibrios species are:
V. cholerae.
V. parahaemolytica.
129
cholerae are divided into at least .... known serogroup.
These classification according to ......
Its antigenic structure consist of a .....antigen and ..... antigen.
It is grow well in ordinary media.
It is grow on ..... selective media & produce visible ....
It fermenting ....
It reduces ....
Catalase and oxidase ....
Urease .....
It susceptible to heat, drying & acid.
It cause .... disease.
139
differences in their (O) lipopolysaccharide antigens.
flagella ( H)
somatic (O)
TCBS
yellow colonies .
carbohydrate with acid production.
nitrate to nitrites.
positive
negative
cholera
130
Classification of vibrio cholerae:
Vibrio cholerae serogroup O1 & O139:
These are causative agents of ....
V. cholerae O1 are subdivided into three serotypes on the basis of surface characteristics- .....
Vibrio cholera non-O1 / non-O139 serogroup:
These are involved in cases of mild diarrhea and ....
epidemic cholera .
Ogawa, Inaba, & Hikojima.
sporadic forms of cholera –like diarrheal disease in man , but not epidemics.
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CHOLERA
........
Induced by ..... secreted by V.cholerae serogroup O1 & O139.
Produce profuse watery diarrhea with characteristic ......
Secretory , non- inflammatory severe diarrheal disease.
enterotoxin
rice watery stool that contains flakes of mucous, shed epithelial cells and large number of vibrios.
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Pathogenesis of cholera
Infection is transmitted by .... through contaminated water or food by excreta of a case or a carrier.
Other common vehicles include contaminated ....
Cholera is not an ...... infection.
The organism do not reach the blood stream but remain within the .....
It attached to the intestinal microvilli by ......
.... capsule prevent phagocytosis.
The organism multiply and liberate ....
B-subunit binds to ....
A-subunit activates .. ... causing hypersecretion of water& elactrolytes to the lumen .
Also they liberate ..... help the organism to penetrate the mucous layer of the small intestine.
The incubation period ....
.
Sudden onset of nausea, vomiting, abdominal cramps , profuse ..... diarrhea with rapid loss of fluid and electrolytes .
...... and are complications of the disease.
faeco-oral route
fish and shellfish.
invasive
intestinal tract.
fimbria
polysacchride
cholera enterotoxin (heat- labile consisting of A-B subunits).
GM1 ganglioside receptor on the cells lining the intestine, promote A –Subunit entry.
adenylate cyclase ( increase intracellular cAMP),
mucinase enzyme ;
1-4 days
watery
Dehydration , tachycardia, tachypnea, hypotension, hypokalemia, anuria, circulatory collapse
133
In case of delay of examination of cholera, specimens are ..
kept in transport media ( e.g. Cary Blair transport media).
134
Culture of cholera
Fresh stool can be directly plated on a non-selective medium like .....
Selective medium such as ....
Macconkey agar (pale,non lactose fermenting).
TCBS (Button shaped yellow colonies).
135
Cholera red reaction (
produce indole from peptone & reduce nitrate to nitrite)
136
Vaccine of cholera
Combination inactivated whole cell & cholera....subunit vaccines provide limited protection.
toxin B
137
Vibrio parahaemolyticus
It is a .. (salt tolerant ) organism.
Requires the presence of ... To grow
It causes ....
.
This disease as a result of ...
halophilic.
sodium chloride.
acute gastroenteritis .
ingestion of raw or improperly cooked seafood .
138
Pathogenicity:Vibrio parahaemolyticus
... toxin ( thermostable hemolysin).
is a heat stable cytotoxin has an .... activity:
Fluid and electrolytes loss.
Adhere to human intestinal cells causing ...
Kanagawa hemolysin
enterotoxic
tissue damage, inflammation and blood loss.
139
Clinical picture:- Vibrio parahaemolyticus
After short incubation period (12-24hr) , ...... occur.
nausea, vomiting, abdominal pain, fever and watery to bloody diarrhea
140
)- Vibrio parahaemolyticus
The organism grow well on... agar & .... ( green colonies).
blood
TCBS
141
Vibrio parahaemolyticus
kanagawa phenomenon
It cause β hemolytic colonies in human red cells in a special media containing mannitol (known as
142
Sexually transmitted infections (STI), also referred to as ........
Infections that are commonly spread by sexual activity, especially .....
sexually transmitted diseases (STD) or venereal diseases (VD).
vagina intercourse , anal sex and oral sex.
143
STD Symptoms and signs of disease may include .....
vaginal discharge, penile discharge, ulcers on or around the genitals, and pelvic pain.
144
STIs can be transmitted to an .... before or during childbirth and may result complications for the baby.
infant
145
Different .... can be transmitted through sexual activity.
Bacterial STIs include ...
B. Viral STIs include ...
C. Parasitic STIs include ....
D. Fungal STIs include vaginitis by ...
Some STIs can be spread by non-sexual contact with donor tissue, blood, breast feeding or during childbirth.
bacteria, viruses, fungus and parasites
chlamydia, gonorrhea, chancroid and syphilis.
genital herpes, HIV/AIDS, and genital warts( Human papillpma virus)
trichomoniasis
Candida albicans.
146
Discharge diseases: std
Gonorrhea
Chlamydia
147
- Genital ulcer diseases
Syphilis
Chancroid
Genital herpes:
148
)- Wart diseases STD
Human papilloma:
- Molluscum contagiosum:
149
Vaginitis
The most common cause is Candida albicans.
Trichomonas vaginalis
Gradnerella species :
150
Gonorrhea :
The causative agent .... bacteria.
Symptoms in men include ...
Cause ... in males.
Many cases are asymptomatic .
In female both the will be infected.
Vaginal discharge, burning or itching while urinating, painful sexual intercourse.
Salpingitis which lead to ...
N .gonorrhea
burning and pain during urinating, increased urinary frequency, discharge from the penis (white, green, or yellow in color),
urethritis
urinary and genital tracts
PID
151
Chlamydia
Causative agent is ...
In males , the bacterium causes an ...
Females have ...
Invade the lymphatic tissues , causing ...
Genital discharging diseases (( In addition to vaginitis & vagiosis))
Chlamydia trachomatis.
inflammation of the urethra.
cervicitis, discharge, salpingitis and frequently PID .
lymphogranuloma venereum.
152
Syphilis:
Caused by ...
There are three distinct clinical stages:
Primary syphilis with ...
Secondary syphilis with ...
iii. Latency & Tertiary syphilis :
About 30% of infections enter a highly varied latent period.
iv. Tertiary stage characterized by ... in many tissues & ....
v. Congenital syphilis with stillbirth.
Treponema pallidum.
genitalia hard chancre ( small, red , hard bump that enlarged & break down leaving a shallow crater with firm margins).
flu-like symptoms , lymphadenopathy , peculiar red or brown skin rash and systemic complications.
Gummas
nuerosyphilis
153
Chancroid:
The causative agent is ...
Characterized by ... ( very painful in male & may unnoticed in famale) with ...
Haemophilus ducreyi ( Gram negative rod).
genitalia soft chancre
lymphadenopathy
154
Genital herpes:
Caused by ...
Characterized by ...
....can develop in severe cases.
Patient that recover remain asymptomatic or experience recurrent infections.
Neonate herpes through infected motherʹ s genitalia during birth can be fatal.
herpes simplex viruses (HSVs- 2).
fluid –filled , painful vesicles on the genitalia, perineum, thigh & buttocks.
Meningitis or encephalitis
155
Human papilloma:
The causative agent are ...
Characterized by ....on the vulva, in and around the vagina in female.
Warts in and on the... and the... in male.
Both sexes may complain ....
Condyloma acuminata are characterized ....
Certain type of the virus can cause cervical cancer or neoplasia in female & penis cancer in males.
human papilloma viruses (HPVs).
soft, flesh-colored warts outgrowths
penis
scrotum
warts in or on anus and skin around the groin.
cauliflower like masses on external genitalia & perianal areas.
156
)- Molluscum contagiosum:
Causative agent belong to ...
Characterized by lesions in the ...
pox virus family.
genitalia mucosa or on the genital skin area.
157
4)- Vaginitis
A)-The most common cause is ...
Also known as a ...
Characterized by ...
Candida albicans.
yeast infection.
itching white membranous patches and white curdlike discharge with irritation.
158
Trichomonas vaginalis:
Small , pear shaped protozoa.
It cause mostly asymptomatic infections in females .
Vaginitis symptoms may occur include ...
Pregnant women may complain of ...
Chronic infection may lead to ....
a white to green frothy discharge.
premature labor .
infertility
159
Gradnerella species :
These bacterium associated with vaginosis that has ...
Vaginosis could lead to ...
fishy odor discharge & itching without vagina inflammation.
PID complcations.
