MICROBIOLOGY mci screeningt test and indian medical examz high yield important topics study tips
By Live Dr - Wed Feb 11, 2:48 am
|They are prokaryotes; nucleus and cytoplasm not well developed||Eukaryotes; nucleus and cytoplasm are well developed|
|Divide by binary fission||Divide by sexual and asexual methods of reproduction|
|Do not show true branching except actinomycetes||They do show true branching|
|Sterols absent||Sterols present.|
*Chemical present in gram positive bacterial wall but absent in gram negative bacteria is Teichoic acid.
When a suspension of a capsulated bacterium is mixed with its specific anticapsular serum, and examined under microscope, capsule becomes very prominent and appears swollen.
|Thermophilic bacteria||Grow best at high temperatures 55-80 degrees|
|Mesophilic bacteria||Grow best at 25-40 degrees|
|Psychrophilic bacteria||Grow best below 20 degrees|
|Transformation||Transfer of genetic information through the agency of free DNA|
|Transduction||Transfer of a portion of DNA from one bacterium to another through the agency of a bacteriophage.|
|Transposons||Jumping genes consisting of inverted repeat sequences, responsible for transferable drug resistance.|
|Conjugation||Transfer of genetic elements after actual physical contact between a male donor bacterium and female recipient.|
Physical methods of sterilization
|Hot air oven||160 degrees for 1 hour
Used for sterilizing glassware, sharps, all glass syringes, swabs, liquid paraffin, dusting powder, fats, silicone rubber.
Sterilization control- Spores of nontoxigenic strain of clostridium tetani are used to test the efficiency of sterilization
Also Browne’s tube is used
|Vaccine baths||60 degree for 1 hr.
For vaccines of nonsporing bacteria
I am prepared for the worst, but hope for the best.-Bejamin Disraeli
ELEVENTH HOUR MICROBIOLOGY 56
Physical methods of sterilization CONTINUED…
|Pasteurization||Holder method- 63 degrees for 30 min
Flash method- 72 degrees for 15 seconds followed by rapid cooling to 13 degrees or lower.
Used in pasteurization of milk
|Inspissator||80-85 degrees for ½ hour on 3 successive days
Used for sterilizing LJ medium and Loeffler’s serum slope
|Tyndallisation||100 degrees for 20 minutes on 3 successive days
For sterilization of media containing sugar or gelatin.
|Autoclaving||120 degrees for 20 minutes.
Sterilization control- spores of Bacillus stearothermophilus
Sterilization of culture media, masks and caps, surgical instruments.
|Infrared radiation||Used for rapid mass sterilization of prepacked items such as syringes and catheters|
|UV rays||Disinfecting entryways, operation theaters, laboratories.|
|Gamma rays||Sterilizing plastic syringes, swabs, catheters,|
|70 % Ethyl alcohol and isopropyl alcohol||Skin antiseptics|
|Glutaraldehyde||Sterilizing, endoscopes, anesthetic tubes, endotracheal tubes|
|Ethylene oxide||Sterilizing heart -lung machine, respirators, suture, dental equipments|
|Formaldehyde gas||Fumigation of operation theaters|
|Betapropiolactone||Fumigation of operation theaters|
|liquid media||solid media|
|Do not exhibit specific characteristics for identification||Do exhibit|
|Difficult to isolate different types of bacteria from mixed population||Easy to isolate|
|Large volumes of substances can be tested||Not so|
|Bulk cultures of Ig and vaccines can be prepared||Not so|
|Bacteria grow diffusely in liquid media||Bacteria produce discrete visible growth|
Laughing lowers levels of stress hormones and strengthens the immune system. Six-year-olds laugh an average of 300 times a day. Adults only laugh 15 to 100 times a day.
ELEVENTH HOUR MICROBIOLOGY 57
Characteristics of various media
|Simple media||Contains simple substances , like nutrient agar and nutrient broth|
|Complex media||Have ingredients which are added to bring out specific characteristics|
|Synthetic media / Defined media||Prepared from pure chemical substances|
|Enriched media||Nutritive substances like blood or egg are added for the growth of bacteria with exacting nutritional needs|
|Enrichment media||Liquid media in which growth promoting or substances which are growth inhibiting for non desired bacteria are added|
|Selective media||Substances inhibiting growth of unwanted bacteria are added to solid media|
|Indicator media||An indicator which changes color on growth of a bacterium is added|
|Differential medium||A substance is added which enables to bring out differing characteristics of bacteria to aid in their identification|
|Sugar media||Sugar is added to media|
|Transport medium||To enable viability of delicate organism during travel, and to inhibit growth of nonpathogens|
*Medium for antibiotic sensitivity test- Mueller Hinton agar
*Swarming is prevented by adding 6 % agar to culture media.
*Lawn culture is used for bacteriophage typing.
*Indicator used in anaerobic jar-
Reduced Methylene blue
|Actively secreted by bacteria||Part of cell wall|
|Enzymatic action||Not enzymatic action|
|Specific pharmacological effect for each toxin||Nonspecific effect|
|Specific tissue affinity||No specific tissue affinity|
|Highly antigenic||Weakly antigenic|
|Action neutralized by specific antibody||Not neutralized by antibody|
|Can be toxoided||Cant be toxoided|
|Mostly by gram positive bacteria||Mostly by gram negative bacteria|
It is a thousand times better to have common sense without education than to have education without common sense.- Robert G. Ingersoll
ELEVENTH HOUR MICROBIOLOGY 58
Mechanism of action of toxins
|Irreversible protein synthesis inhibition||Shiga toxin(shigella dysentriae -1), EHEC, diphtheria toxin, exotoxin A (pseudomonas aeruginosa)|
|ADP ribosylation of G-protein||Pertussis toxin|
|Activation of cyclic amp||LT (ETEC), cholera toxin.|
|Activation of cGMP||Heat stable E.coli toxin.|
Types of hypersensitivity reactions
|Type 1||Ig E mediated, e.g. atopy, anaphylaxis|
|Type 2||Cytolytic, cytotoxic, e.g. antibody mediated.|
|Type 3||Immune complex mediated, e.g. arthus reaction, serum sickness, rheumatoid arthritis, SLE|
|Type 4||Delayed hypersensitivity, e.g. contact dermatitis, Mantoux test.|
|X linked agamma-globulinemia||Pyogenic bacterial infections
Live vaccines are contraindicated
Management-gamma globulin administration
|Common variable immunodeficiency||Late onset hypogammaglobulinemia
Infection with Giardiasis
|Di George syndrome||Thymus hypoplasia
Viral, fungal and bacterial infections.
|Nezelof syndrome||Cellular immunodeficiency with abnormal Ig G synthesis|
|Ataxia telengiectasia||Ig A decreased|
Decreased cell mediated immunity
Decreased Ig M
|Subacute chronic immunodeficiency||Adenosine deaminase deficiency|
Mosquitoes prefer children to adults, and blondes to brunettes.
ELEVENTH HOUR MICROBIOLOGY 59
|Chronic granulomatous disease||Hydrogen peroxide deficiency
Nitroblue tetrazolium negative
|Chediak-Higashi syndrome||Decreased pigments
Peroxidase positive inclusion in WBC
|Job’s syndrome||Cold staphylococcal abscesses|
|Lazy leucocyte syndrome||Peripheral neutropenia
CHARACTERISTICS OF IMMUNOGLOBULINS
|Binds to microorganism and enhances phagocytosis active in blood an tissues|
|Inhibits the adherence of microorganism to the surface of mucosal calls by covering the organism and thereby preventing entry in body tissues|
|Protection against blood invasion by microorganism|
|Specific stimulation of B cells, either activation, cloning, antibody production or suppression|
|Protection against pathogens by most cell degranulations, release of inflammatory cytokines; defense against helminthic infections|
*Highest serum concentration- Ig G
2nd most common -Ig M
Shortest half-life Ig E
|primary immune response||secondary immune response|
|Slow, sluggish, short-lived||Prompt, powerful, prolonged|
|Long log phase||Short log phase|
|Low titre of antibody||High titre of antibody|
|Antibody doesn’t last long||Antibodies last long|
|Ig M is secreted||I g G is produced|
|No negative phase||Negative phase may be seen|
|Produced after one dose||Produced after multiple doses|
|Level of antibody is not effective||Effective|
|Zone||Equivalent amounts of antibody and antigen|
|Post zone||Antigen excess|
Keep your face to the sunshine and you cannot see the shadow. It’s what sunflowers do.- Helen keller
ELEVENTH HOUR MICROBIOLOGY 60
INCUBATION PERIOD OF FOOD POISONINGS / GASTROENTERITIS
|Bacillus cereus (emetic form, Chinese restaurant syndrome)||
|Bacillus cereus ( diarrhoel form)||
|Salmonella food poisoning||
Grape like clusters
Aerobes and facultative anaerobes
Grow on ordinary media
On nutrient agar- large, smooth, circular, shiny colonies.
Produce golden yellow pigment
On nutrient agar slope-oil paint appearance
On blood agar-beta hemolysis
Mac Conkey’s agar-pink colonies
Ferment sugar producing acid but no gas
Mannitol is fermented anaerobically by S. aureaus but not by other species
Catalase positive S. aureus gives prompt phosphatase , while S. epidermidis gives negative or weakly positive result
Non coagulase staphylococci include-
S. epidermidis is the most common cause of infection of central nervous system shunts
S. saprophyticus causes urinary tract infection in sexually active young women.
|Toxin induced diseases by S. aureus|
|Staphylococcal food poisoning
Toxic shock syndrome
Staphylococcal scalded skin syndrome-Ritter’s disease, toxic epidermal necrolysis, Pemphigus neonatorum, bullous impetigo
More people are allergic to cow’s milk than any other food.
ELEVENTH HOUR MICROBIOLOGY 61
|Spherical, arranged in chains
Aerobes and facultative anaerobes
Doesn’t grow on simple, media, require blood or serum, sugars
Blood agar- circular, small, colonies with area of hemolysis around them.
Virulent forms give matt/ granular colonies, while avirulent give glossy colonies
Ferment sugar producing acid but no gas
Do not ferment inulin
*Bacteriocin- highly specific antibiotic like substances produced by certain strains of bacteria, which are active against other strains of the same or different species.
|Retrospective diagnosis of streptococcal infection is done by|
|Anti streptolysin O
Anti DNA-ase B
|Alpha hemolytic streptococci/ viridans streptococci||Greenish discoloration with partial hemolysis|
|Beta hemolytic streptococci||Sharply defined colorless zone of hemolysis|
|Gamma / nonhemolytic Streptocooci /indifferent Streptococci/ Enterococci||No change in medium|
CLASSIFICATION OF STREPTOCOCCI
|Lancefield groups||Hemolytic streptococci are classified by Lancefield , based on nature of carbohydrate antigen C on the cell wall|
|Griffith typing||Those belonging to group A streptococcus pyogenes are further subdivided based on the protein (M, T, R) antigens present on cell surface|
Aerobic and facultatively anaerobic
N gonorrhea ferments glucose, but not maltose
N. meningitides ferments both.
Sometimes we stare so long at a door that is closing that we see too late the one that is open.-Alexander Graham Bell
ELEVENTH HOUR MICROBIOLOGY 62
|Gram negative, aerobic, nonsporing, nonmotile,
Exacting growth requirements
Solid media- round, bluish grey, smooth, glistening, butyrous.
Weak hemolysis on blood agar
|Small, lanceolate, diplococci
Grow only in enriched media
Aerobes and facultative anaerobes
Blood agar- under aerobic conditions, small, dome shaped, shiny colonies with greenish discoloration (alpha hemolysis), with central umbonation, giving carom coin or draughtsman appearance
Under anaerobic conditions-they show beta hemolysis
Ferment sugars forming acid but no gas
Ferment inulin , bile soluble
Catalase and oxidase negative
Sensitive to optochin
|Corynebacterium diphtheriae/ Klebs Loeffler bacillus|
|Slender rod, clubbing at end, pleomorphic, nonsporing, nonmotile, noncapsulated, gram positive
Metachromatic granules composed of polymetaphospahate, stained with Loeffler’s Methylene blue, give bluish purple color.
Also called volutin or Babes Ernst granules, or polar bodies.
Bacilli are arranged in Chinese letter or cuneiform pattern
Loeffler’s serum slope-growth within 8 hours.
Tellurite blood agar is the selective medium-grey or black colour colonies.
Ferment sugar producing acid but no gas.
|Large capsulated bacilli
Arranged in long chains, giving bamboo stick appearance.
In ancient Egypt, Priests plucked every hair from their bodies, including their eyebrows and eyelashes.
ELEVENTH HOUR MICROBIOLOGY 63
|BACILLUS ANTHRACIS CONTINUED…|
|M’Fadyen’s reaction-when blood films containi8ng anthrax bacilli are stained with polychrome-Methylene blue, and examined under microscope, capsule is detected as amorphous purplish material around the bacilli
Aerobic and facultatively anaerobic
Grows on ordinary media
Agar-round, grayish colonies with frosted glass appearance, which under low power resembles locks of matted hair, called medusa head appearance.
Gelatin swab culture- inverted fir tree appearance
String of pearls reaction- when grown on solid media containing penicillin, cells become large spherical and in chains.
|Clostridium perfringens / Cl. welchii / Bacillus aerogenes capsulatus / bacillus phlegmonis emphysematous|
|Gram positive bacillus
Subterminal spores, resembling club shape.
Straight bacillus, pleomorphic, capsulated nonmotile.
Robertson’s cooked meat medium
In litmus milk fermentation of lactose, formation of acid, , clot and gas is seen. Stormy fermentation.
Blood agar- target hemolysis.
Ferments sugar to produce acid but no gas
Nagler reaction- when grown on agar with antitoxin spread on one half there will be no opacity around the colonies on the half of plate having antitoxin, due to specific neutralization of alpha toxin.
|Gram positive, slender with spherical bulging, spores at the ends, giving a drumstick appearance( tennis racket appearance is given by Cl. tertium )
Grows on ordinary media
Deep agar shake agar cultures- spherical fluffy balls colonies
In gelatin swab-fir tree type of growth
Robertson’s cooked meat broth, turbidity and gas, proteolytic.
Blood agar- alpha hemolysis, which later develops into beta hemolysis, due to tetanolysin.
You may never know what results come of your action, but if you do nothing there will be no result.- Mahatma Gandhi
ELEVENTH HOUR MICROBIOLOGY 64
|Gram negative, straight rod, motile by peritrichate flagella.
Aerobe and facultatively anaerobe
Hemolytic on blood agar
Mac Conkey’s medium-bright pink colonies, due to lactose fermentation.
Ferments sugars with the production of acid and gas.
Produces urease, rapidly hydrolyses urea to ammonia and carbon dioxide.
Gram negative, noncapsulated, pleomorphic, motile rod.
Cultures give a fishy or seminal odour.
Mac Conkey’s medium-colour less medium.
Weil Felix reaction-heterophilic agglutination due to the sharing of carbohydrates hapten by proteus and rickettsiae.
|Gram negative, rods, nonmotile, nonsporing, noncapsulated,
Aerobes and facultative anaerobes.
Grow on ordinary media
Mac Conkey’s- colorless colonies, except shigella sonie which is late lactose fermenter.
Deoxycholate citrate agar, selective medium.
|Gram negative, comma shaped, actively motile by polar flagella, characteristic vibratory/ darting motility, like a swarm of gnats.
Nonsporing , noncapsulated
In stained films show, fish in stream appearance,
Strongly aerobic, Mac Conkey’s colour less colonies.
Blood agar, colonies show surrounding zone of greening, followed by clearing, due to hemodigestion
Gelatin stab culture- funnel shaped or turnip shaped liquefaction.
Venkatraman- Ramakrishnan medium- and Cary Blair medium- is the holding or transport medium.
Alkaline peptone water and Monsur’s taurocholate tellurite peptone water are transport and enrichment medium.
Tcbs is the preferred plating medium- yellowish green colonies.
The kerosene fungus can live in jet fuel tanks. If there is a minute amount of water in the tank, the fungus can use the fuel as food.
ELEVENTH HOUR MICROBIOLOGY 65
|Gram negative, motile with peritrichate flagella.
Aerobic and facultatively anaerobic.
Mac Conkey’s agar-and Deoxycholate citrate – colonies are colorless due to absence of lactose fermentation.
Wilson and Blair medium- jet black colonies, due to H2S production.
Selenite F broth and tetra thionate broth are enrichment media
Ferment sugars producing acid and gas, except salmonella typhi which is anerogenic.
|Carriers in typhoid|
|3weeks to 3 months- convalescent carrier
3 months to 1 year- temporary carrier
More than 1 year- chronic carrier
|Aerobic, nonsporing, gram negative, motile by polar flagella,
Grows on simple media- colonies give musty or earthy smell.
Mac Conkey’s and dca colorless colonies.
Produces pigments-pyocyanin-bluish green, fluorescin /pyoverdin-greenish yellow, pyorubin-red, pyomelanin- brown.
Are capable of surviving and multiplying in hot water
Causative agent of hot tub folliculitis
|Gives safety pin appearance (Bipolar staining)
Similar safety pin appearance in Burkholderia pseudomallei
Ghee broth culture-stalactite growth is seen.
Reservoir of plague
|Haemophilus influenzae/ Pfeiffer bacillus|
|Gram negative, capsulated.
Fastidious growth requirements, require accessory growth factors, named X and V
|Shows bipolar staining
Bacilli are arranged in whorls or parallel chains, giving school of fish or rail road track appearance.
|It is sometimes as dangerous to be run into by a microbe as by a trolley car.-J.J. Walsh|
ELEVENTH HOUR MICROBIOLOGY 66
|antigenic drift||antigenic shift|
|Gradual, sequential||Abrupt discontinuous|
|New antigens are related to previous antigens||New antigens are unrelated to previous ones|
|Cause periodical epidemics||Cause major epidemics or pandemics|
|Accounted to mutation and selection||Cannot be accounted to mutation|
|Bordetella pertussis/ Bordet Gengou bacillus|
|gram negative, strict aerobes, produce toxins., capsulated
In culture films, thumb print appearance.
Bordet-Gengou glycerin -potato-blood agar-selective medium-
Dome shaped smooth, opaque, grayish white colonies, –bisected pearls or mercury drops appearance.
Colonies are surrounded by a hazy zone of hemolysis; confluent growth gives aluminum paint appearance.
|Brucellosis is also known as Mediterranean fever, Malta fever, undulant fever.
Transmitted through unpasteurised milk.
Gram negative, strict aerobic,
Catalase, oxidase and urease positive
Antigenic cross reactions between Brucella and vibrio cholera.
Due to presence of mycoloic acid.
Generation time is 14-15 hours.
Lowenstein Jensen medium is the most widely used solid medium.
Collies are rough, tough and buff.
On liquid media, gives a surface pellicle.
0.5 ml of PPD, having 5 tu is injected intradermally, on the flexor aspect of forearm,
Result is read after 72 hours.
Positive tuberculin test indicates hypersensitivity to tuberculin protein due to infection with tubercle bacillus or bcg immunization
|Induration > 10 mm||Positive|
|5 mm or less||Negative|
There are more living organisms in one average human body than there are humans in the whole world.
ELEVENTH HOUR MICROBIOLOGY 67
|False negative test||Miliary tuberculosis
Convalescence from measles, lymphoreticular malignancy, severe malnutrition, immunosuppression, immunodeficiency.
|False positive||Infection with atypical bacteria.|
SENSITIVITY OF DETECTION METHODS
|Liquid broth||1-10 bacteria|
|Solid media||100 bacteria|
Grading of smears
|1+||1-10 in whole slide|
|2+||1-10 in 100 oil fields|
|3+||1-10 in 10 oil fields|
|4+||1-10 in every filed|
|Photochromogens||No pigment in dark, but on exposure to light.
e.g. M. kansasii, M. marinum, M. simiae.
|Scotochromogens||form pigment even in the dark
M. intracellulare/ Battey bacillus
|Rapid growers||Colonies appear within 7 days.
|M. ulcerans||Ulcers on legs and arms, produces toxin|
|M.marinum/ M. balnei||Causes swimming pool granuloma|
|Neutral red test||Differentiates virulent from non virulent|
|Niacin test||Positive with human type|
|Arylsulfatase||Positive with atypical|
|Catalase- Peroxidase||Differentiates typical from atypical
sensitivity to Isoniazide
A wise man learns by the mistakes of others, a fool by his own. Latin Proverb
ELEVENTH HOUR MICROBIOLOGY 68
|AFB positive structures|
Ascospores of some yeasts
|Gram positive and acid fast
Morphological index-live bacilli appear solid and uniformly stained, whereas dead bacilli appear fragmented.
The percentage of uniformly stained bacilli is called morphological index.
Number of bacilli in tissues.
They frequently agglomerate; these masses are known as, globi.-giving a cigar bundle appearance.
They are not cultivable.
Can be grown in footpads of mice kept at 20 degrees.
And in nine banded armadillo
Generation time is 12-13 days.
Grading of smears
|1+||1-10 bacilli in 100 fields|
|2+||1-10 bacilli in 10 fields|
|3+||1-10 bacilli per field|
|4+||10-100 bacilli in every filed|
|5+||> 100 bacilli in every field, clumps and globi|
GRADING FOR BACTERIAL INDEX
|Negative||No bacilli in 100 fields|
|+||1 or less in each field|
|++||Bacilli in all fields|
|+++||Many bacilli in all fields
Bacterial index = total numbers of + for each smear divided by the number of smears
Minimum 7 sites should be smeared
In paucibacillary, it is < 2
In multibacillary > 2
Vaccination was discovered by English physician Edward Jenner, after he observed that milkmaids would not catch smallpox since they caught benign cowpox first.
ELEVENTH HOUR MICROBIOLOGY 69
It can be seen in low microscope by negative staining with India ink.
Morphology and motility can be seen under dark ground or phase contrast microscope.
It can be stained with silver impregnation method
Coiled appearance seen under dark ground microscopy
Their ends are hooked, resembling umbrella handles.
Generation time is 12-16 hours.
|Devoid of cell wall, pleomorphic.
Show true branching.
Aerobic and facultatively anaerobic.
Biphasic colonies, with a fried egg appearance
Require cholesterol for growth.
*Rickettsiae are obligate intracellular parasites, transmitted by arthropod vectors.
*Chlamydiae are obligate intracellular parasites.
Called energy parasites.
Occur in two forms
Elementary body- extracellular, infective form
Reticulate body/ initial body.-intracellular, growing and replicative form.
Differences between classical and Eltor vibrio
|characteristic||classical vibrio||Eltor vibrio|
|Vogs Proskauer reaction||
|Chick RBC agglutination||
|Eltor phage 5 susceptibility||
|Polymyxin b sensitivity||
|Group 4 phage susceptibility||
When it is obvious that the goals cannot be reached, don’t adjust the goals, adjust the action steps.- Confucius
ELEVENTH HOUR MICROBIOLOGY 70
|UREASE POSITIVE BACTERIA|
|R. prowazekii||Epidemic typhus
|Endemic typhus||Rat flea / Cat flea|
|R. ricketsii||Rocky mountain spotted fever||Tick|
|Orientia tsusugamushi||Scrub typhus||Trombiculid mite|
|R. Quintana||Trench fever||Louse|
|R. akari||Rickettsial pox||Mite|
|Coxiella burnetti||Q fever||–|
|Eaton agent||Mycoplasma pneumoniae|
|Johne’s bacillus||Mycobacterium pseudo tuberculosis|
|Eberth Gaffky bacillus||Salmonella typhi|
|Koch Week’s bacillus||Haemophilus aegypticus|
|Whitmore bacillus||Pseudomonas pseudomallei|
*Paul Bunnel test is used for diagnosing infectious mononucleosis.
Kissing disease-infectious mononucleosis, as kissing is the predominant mode of transport.
|Yeast like fungi||Partly yeast partly hyphae||Candida|
|Moulds / filamentous fungi||True mycelia||Dermatophytes|
|Dimorphic||Filaments and yeasts at different temperatures.
Yeast at 37 degrees and mould at 22 degrees
|Coccidiodes, blastomyces, Paracoccidiodes, histoplasma|
|Allantoic cavity||Vaccine production of influenza|
|Amniotic cavity||Primary isolation of influenza|
|Yolk sac||Chlamydia, Rickettsia|
A dentist invented the electric chair.
ELEVENTH HOUR MICROBIOLOGY 71
BLOT TESTS WITH STRUCTURES DETECTED BY THEM
* Southern was the name of a scientist.
|Bollinger bodies||Fowl pox|
|Cowdry A inclusion bodies (Lipschultz)||Herpes, yellow fever|
|Cowdry B inclusion bodies||Adenovirus polio virus|
|Molluscum bodies||Molluscum contagiosum|
|Torres bodies / councilman bodies||Yellow fever|
|Warthin Finkeledy cells||Measles|
*Universal precautions apply to blood csf, synovial fluid, pleural fluid, pericardial fluid, amniotic fluid, saliva , breast milk, semen, vaginal secretions,
Does not apply to feces, nasal secretions, sputum, sweat, tears, urine, and vomitus.
Differences between P. vivax and P. falciform
|Incubation period||14 days||12 days|
|RBC size||Enlarged||Not enlarged|
|Dots||Schuffner’s dots||Maurer’s dots|
|Infection||Usually single per rbc||Multiple infections|
|Stages||All stages seen||Only rings and gametocytes|
|Special forms||None||Accole, wing, marginal|
|Resistance||No resistance||Drug resistance widespread|
|Parasites found in blood|
It is hard to fail, but it is worse never to have tried to succeed.- Theodore Roosevelt
ELEVENTH HOUR MICROBIOLOGY 72
Parity of nematodes
|African trypanosomiasis||Sleeping sickness||Tsetse fly||T. brucei|
|American trypanosomiasis||Chaga’s disease||Reduvid bug||T. cruzi|
|Man is the secondary host for|
|Visceral larva migrans||Toxocara canis|
|Larva currens||S. stercoralis|
|CHARACTERISTIC||classical filariasis||occult filariasis|
|Cause||Developing worms and adults||Microfilariae|
|Organs involved||Lymphatic system||Lymphatic system, lungs, liver and spleen|
|Therapeutic response||No response||Responds to DEC|
|Microfilaria||Present in blood||Present in affected tissues|
|Eggs which do not float in saturated solution of common salt|
|Unfertilized eggs of Ascaris lumbricoides
Eggs of Tenia solium and Tenia saginata
All trematodal eggs
Larvae of strongyloides
|Calabar swelling||Loa Loa affection of eyes|
|Onchocercomas||Subcutaneous fibrous nodules in case of O. volvulus|
*Occult filariasis / Mayers-Kouwenaar syndrome
Loa Loa-microfilaria are detected in blood in daytime
|Tenia saginata||Praziquantel- Niclosamide|
*Niclosamide is not used in infection with Tenia solium as ova released from the damaged worms causes Cysticercosis
Powdered tea was once used as a snuff to stop bleeding noses.
ELEVENTH HOUR MICROBIOLOGY 73
Wishing you all great success in life.