مختصرات طبية
أهم الاختبارات في علم الأحياء الدقيقة
أهم الاختبارات في علم الأحياء الدقيقة
(Most Important of Tests for Microbiology)
Anti Streptolysin O test, ASO
(اختبار مضاد الستربتوليسين)
سنوضح هنا طريقة عمل الاختبار إضافة إلى شرح نتائجه مع أهمية هذا الاختبار وبماذا يستخدم؟
Principle:
الستربتوليسين O هو مادة سامة تنتجها s.pyogenes، والتي تكسر غشاء الخلية المضيفة
it’s higly immunogenic >>> induction of specific Antibody Formation
Titres up to 200 >>> normal
Above 200 “usually above 500” >>> Acute Rheumatic fever
Importance :
تحديد العدوى السابقة بواسطة S.pyogenes
Determine previous infection by S.pyogenes in suspected ARF.
Quellung Test
Capsular Swelling Test
Principle:
التفاعل بين الكبسولة “المستضد” والأجسام المضادة المحددة ضدها، مما يؤدي إلى انتفاخها تحت المجهر
Importance:
تشخيص عدوى S. Pneumoni & Hemophillus influenza
Elek’s Test
Principle:
الفحص المختبري الأكثر شيوعًا لقياس التسمم
Toxin production is detected by Formation of
Toxin-Antitoxin Precipitation lines
Importance :
تشخيص عدوى C.diphtheriae السامة
McFadyean Reaction
Principle :
الكشف عن المواد المحفظة من عصيات الجمرة الخبيثة في اللطاخات من الأنسجة المصابة بعد صبغها ب:
Polychrome Methylene Blue stain
تظهر عصيات زرقاء في الخلفية التي تكون ملونة أرجوانية / وردية
Importance:
تشخيص الجمرة الخبيثة بواسطة الكشف المباشر عن B.anthracis وتحليل المواد في الكبسولة الخاصة بها
Stormy Clot Reaction
Principle :
في Litmus Milk يتخمر اللاكتوز الخاص ب C.perfringens
a. Acid >> clotting of milk
b. Large amount of Gas >> splits clotted milk into pieces
Importance :
تشخيص عدوى C.perfringens كما في حالات الغرغرينا الغازية
Nagler’s Reaction
Principle :
يتم زرع C.perfringens على Egg yolk agar >> مستعمرات محاطة بمناطق مبهمة
Due to production of Alpha Toxin” lecithinase enzyme “
This is inhibitid by Anti Alphe toxin
Importance :
تشخيص C.perfringens
Tuberculin skin test
Principle :
اختبار جلدي يكشف عن الاستجابة المتأخرة لفرط الحساسية للتعرض المسبق للمضيف لمرض السل M.tuberculosis.
Importance:
الاختبار الرئيسي في تشخيص عدوى السل الكامنة M.tuberculosis
Technique
0.1 ml PPD
purified protein derivative
+
5 tuberculin units
injected intradermally in skin of front forearm
48-72 hrs >> Induration
Lepromin Test
principle :
تشير إلى القدرة على إنتاج مناعة خلوية ضد M.leprae
Lepromin is heat killed suspension of M.leprae from armadillo tissue
Importance:
لا يوجد قيمة تشخيصية ولكن هناك:
Prognostic value
+ve for tuberculous
-ve for lepromatous
Brucillin Test
Principle:
مثل اختبار tuberculin test “تفاعل فرط الحساسية المتأخر”
Importance :
تشخيص عدوى كل من Brucellosis infection undulant , malta fever
String Test
Principle : large colony + 5% sodium desoxycholate + sterile distilled H2O
60 sec >>>
1.the cell lyse
1.the cell lyse
2.lose turbidity
3.DNA strings appears
2-3 cm
” زى المعلقة فى الملوخية “c
+ve for all Vibrio
-ve for Aeromonas
Importance:
التفريق بين كل من:
التفريق بين كل من:
Vibrio
&
all bact. species that has similarities with vibrio particularly
Aeromonas
Biopsy Urease Test
Principle :
يتم وضع عينة خزعة المعدة على وسائط تحتوي على اليوريا
H.pylori is strong urease producer
if the urea is hydrolyzed into Co2 & ammonia >>> H.pylori infection
Importance :
تشخيص عدوى H.pylori ، أي Peptic Ulcer
Urea Breath Test
Principle :
ابتلاع اليوريا المشعة التي تحتوي على C13 أو C14
H.pylori Ureas سوف يحلل اليوريا إلى كربونات حيوية التي سوف:
exhaled as
Labeled CO2
Importance :
تشخيص عدوى H.pylori ، أي Peptic Ulcer
خطوات السيطرة على تفشي مرض معد:
2I
Investigation .. to trace the source of the infection
Immunization activities
Non-Hepatotropic viruses
2V , 2c
Varicella
Viral hemorrhagic fevers
CMV .. cytomegalovirus
Coxsackie
ENDOTOXIN
Endothelial cells/ Edema
Negative .. gram- bacteria
DIC/ Death
Outer membrane
TNF
O-antigen
X-tremely heat stable
IL-1
Nitric oxide/ Neutrophil chemotaxis
Acute post-streptococcal glomerulonephritis: classic presentation
“Sore throat, Face bloat, Pi$$ coke”
Sore throat: 1 week ago
Face bloat: facial edema
Pi$$ coke: coke-coloured urine
Alternatively, short version: Throat, bloat and coke
Staphylococcus aureus: diseases caused
SOFT PAINS
Skin infections
Osteomyelitis
Food poisoning
Toxic shock syndrome
Pneumonia
Acute endocarditis
Infective arthritis
Necrotizing fasciitis
Sepsis
Food poisoning: bugs inducing
“Eating Contaminated Stuff Causes Very Big Smelly Vomit”
E. coli O157-H7 > under*****d meat, esp. hamburgers
Clostridium botulinum > canned foods
Salmonella > poultry, meat, eggs
Vibrio parahaemolyticus > seafood
Bacillus cereus > reheated rice
Staphylococcus aureus > meats, mayo, custard
Clostridium perfringens > reheated meat
Vibrio vulnificus > seafood
Streptococcus pyogenes: virulence factors
SMASHED
Streptolysins
M protein
Anti-C5a peptidase
Streptokinase
Hyaluronidase
Exotoxin
DNAses
Streptococcus pyogenes: diseases caused
NIPPLES
Necrotising fasciitis and myositis
Impetigo
Pharyngitis
Pneumonia
Lymphangitis
Erysipelas and cellulitis
Scarlet fever/ Streptococcal TSS
Endocarditis: lab results suggesting it
“High Tech Lab Results Point At Endocarditis”
Hematuria
Thrombocytopenia
Leukocytosis, -penia
Red blood cell casta
Proteinuria
Anemia
Elevated ESR
cepholosporins
CEPHALOSPORINS-tough but important
schedule of parents
1 pm:take a ZOLI(bag) and roam with a THIN FELLOW
2 pm:start ROXI video and watch TINTIN
3 pm:take a TAXI go to ZOne.where they meet one ZIDI boy who has worn PER AXONS slippers
4 pm:to cure PIMPLES they go to ROME
schedule of ORACLE
1 pm:go to DR.ALEX REDI’s house
2 pm:because of aCHLORhydria he starts watching ROXI video and watch AXN
3 pmIN FIXes PROduction of BUTEN
now what is this >>
parents means parental root
1st generation cephalosporins:cePHALOTHIN,cef aZOLIN
2nd generation:cefuROXIME,cefoxiTI N
3rd generation:cefoTAXIme,ceftiZOx ime,ceftaZIDIme,ceft riAXONE,cefoPERazone
4th:cefePIME,cefpiROM
ORACLE means oral root
1st gen:cefaDRoxil,cephALEXIN,ceph RADIne
2nd gen:cefACHLOR,cefuROXIme AXetil
3rd gen:cefDINir,ceFIXime,cefpodox ime PROxetil,ceftiBUTEN
Capsulated pathogenic organisms are
Some Killers Have Pretty Nice Capsules
S Streptococcus pneumoniae
K Klebsiella pneumoniae
H Haemophilus influenzae
P Pseudomonas aeruginosa
N Neisseria meningitidis
C Cryptococcus neoformans
Remeber… All bacilli are gram negative except > L.DATTA
L – Listeria
D – Diphtheria
A – Actinomycetes
T – Tetani Clostridium
T – TB Mycobatcterium
A – Anthrax bacillus
Hypersensitivity reactions: Gell and Goombs nomenclature
ACID
• From I to IV
Anaphylactic type: type I
Cytotoxic type: type II
Immune complex disease: type III
Delayed hypersensitivity (cell mediated): type IV
MHC I vs. II: T cell interaction
The “=8” equation
2×4=8, and 1×8=8
MHC II goes with CD4
MHC I goes with CD8
Immunoglobulin (Ig) types: the important ones worth remembering, in order of appearance
MAGDElaine .. a girl’s ****
IgM
IgA
IgG
IgD
IgE
• Magdelaine tells you the order they usually appear: M first, then A or G
• Alternatively: IgM is IMmediate
Acute inflammation features
SLIPR
Swelling
Loss of function
Increased heat
Pain
Redness
• “What a cute pair of slippers” can be used to tie acute inflammation to SLIPR
Lupus signs and symptoms
SOAP BRAIN
Serositis .. pleuritis, pericarditis
Oral ulcers
Arthritis
Photosensitivity
Blood .. all are low – anemia, leukopenia, thrombocytopenia
Renal .. protein
ANA
Immunologic .. DS DNA, etc
Neurologic .. psych, seizures
Goodpasture’s Syndrome components
GoodPasture is Glomerulonephritis and Pnuemonitits
• From autoantibodies attacking Glomerular and Pulmonary ****ment membranes
Complement: function of C3a versus C3b
C3a: Activates Acute .. inflammation
C3b: Bonds Bacteria .. to macrophages–easier digestion
• If wish to know more than just C3
C3a, C4a, C5a activate acute
C3b, C4b bind bacteria
MHC I vs. MHC II properties
“Immunity helps to exterminate fun for bacteria”
HLA-DR genetic predisposition immune disease examples
HLA-DR
Hashimoto’s disease
Leukemia/ Lupus
Autoimmune adrenalitis/ Anemia .. pernicious
Diabetes insipidous
Rheumatoid arthritis
Complement cascade initiating items: alternative vs. classic
Classic: Combined Complexes
Alternative: Activators Alone, or IgA
• Complexes are made of Ab and Ag combined together
• Examples of activators: endotoxin, microbial surface
