Micro Spots 2 MM PDF

10 Practical Microbiology Salient Features: 1. It is a rapid test...

10 Practical Microbiology Salient Features: 1. It is a rapid test for detection of antibodies against HIV-1 and HIV-2. 2. There is a membrane with one control and two test dots one each for HIV and HIV-2. 3. For positive test, one control and other HIV-1 or/and HIV-2 dots show distinct pinkish purple dots against white Control background. 4. In negative cases, control only shows Positive pinkish purple dot. 5. Principle: (i) HIV antigens are immobilised on a porous immunofiltration. 8.73 HIV-Tridot membrane. Samples and reagents pass through the membrane and are absorbed into the underlying absorbent. (ii) If the patient's sample contains HIV antibodies, these bind to the immobilised antigen. ot (iii) Conjugate binds to Fc portion the HIV antibodies to give pinkish purple dots. XII. WET PREPARATION OF STOOL SPECIMEN Salient features: 1. Bile-stained. scars 2. Scientific name for roundworm 1s n lumbricoides. 3. Route of infection: By ingestion. 4. Infective form: Embryonated egE Fertilized Unfertilized Fig. 8.74 Egg of roundworm POIs Salient features: 1. Egg is not bile-stained. 2. Scientific names for hookworms are duodenale and Necator Ancylostoma americanus. 3. Infective agent: Filariform larva. 4. Portal of entry: Through skin. Fig. 8.75 Egg of hookworm Salient features: 1. Egg is not bile stained. 2. Planoconvex in shape. 3. Common names: Threadworm, pin worm. 4. Clinical features: Pruritus ani. Fig. 8.76 Egg of E.vermicularis Salient features 1. Egg is not bile stained. oncosphere with three 2. It contains an pairs of hooklets. of food 3. Route of infection: By ingestion contaminated with eggs. Fig. 8.77 Egg of H.nana Salient features: is bile stained. 1. Egg 2. Barrel-shaped with a mucous plug at each pole. of 3. Route of infection: By ingestion embryonated eggs. trichiura Fig. 8.78 Egg of Trichuris 112 Practical Microbiolog Salient features: 1. The cyst is quadrinucleate i.e. contains four nuclei. 2. It has a central karyosome present in the nucleu1s. 3. Route of infection: By ingestion of water and food containing cysts. 4. Diseases produced: Fig. 8.79 Cyst of E.histolytica (i) Amoebic dysentery (ii) Extraintestinal amoebiasis. 5. Liver is the most commonly involved extraintestinal amoebiasis. organ in Salient features: 1. The cyst is oval in shape. O 2. It contains four nuclei. a 3. The axostyles lie diagonally, forming wall. dividing line within the cyst of 4. Route of infection: By ingestion cysts. malabsorp 5. G. lamblia infection causes tion. Fig. 8.80 Cyst of Giardia lamblia  XIV. MIsCELLANEOUS ITEMS Salient features: of clinical For inoculation 1. Uses: (i) liquid specimens on solid or media. To transfer bacterial growth (i) to other medium from one biochemical medium to elicit characters. reactions o r other nder red hot 2. Sterilisation: By making it Bunsen-burner flamne. F1g. 8.93 Nichrome wire loop  121 Salient features: 1. Use: To perform 2. It contains 96 ELISA test. 3. ELISA has (8 x 12) wells. been used for detection of antigens and antibodies in various microorganisms such as HIV antibodies, mycobacterial antibodies and detection of O0000O00O hepatitis B markers in serum. PMg. 8.94 Microtitre plate Salient features: 1. Use: To perform Latex agglutination test. 2. Latex agglutination tests are used for detection of hepatitis B antigen, AS0, CRP and RA factor. Fig. 8.95 Latex agglutination tile Salient features: VDRL test to diagnose 1. Use: To perform syphilis. is Treponema 2. Causative agent of syphilis pallidum. test. a flocculatiom 3. VDRL test is VDRL is used in 4. Cardiolipin antigen test. Vig, 8.96 VDRL slide 122 Practical Microbiology Salient features: 1. Use: To detect group B streptococci. Group B Butterfly streptococci 2. CAMP reaction can be demonstrated appearance by the production of accentuated zone of haemolysis (as buttertly Staph. appearance) when aureus streak group B streptococci are inoculated prependicular to a streak of Staph. aureus grown on blood agar. 3. Other test for detection of group B Fig. 8.97 CAMP reaction streptococci is hippurate hydrolysis. 4. Group B streptococci are responsible for neonatal septicaemia and meningitis. Salient features: 1. Uses: i) Demonstration of motilityof bacteria. ii) To obtain motile bacteria rich in H antigen e.g. in Salmonella typhi. 2. 0.2% nutrient agar (soft agar) is used. Fig. 8.98 Craigie's tube Salient features: 1. Use: Technique for anaerobiasis. indicator. 2. Methylene blue is used as an aerobic It becomes colourless in conditions. 8.99 Mcintosh-Filde's jar  123 Salient features: 1. Gas pak is widely used for preparing tasPak anaerobic jars to generate gases. Anaerobic System 2. It is available commercially as a Instruction disposable packet containing pallets of sodium borohydrate, cobalt chloride, citric acid and sodium bicarbonate. These chemicals generate hydrogen and carbon dioxide when water is added. Precaution 3. Hydrogen combines with oxygen in the presence of a catalyst and thus produces DIDrad wilIh core afte use anaerobic conditions in the air-tight jar. Fig 8.100 Gas-Pak Salient features: 1. Uses: (i) For providing 5-10% carbon dioxide as required for growing certain bacteria (Capnophilic bacteria). (i) For recovery of some fastidious microorganisms which require a microaerophilic atmosphere (decrease O,). 2. A lighted candle is kept in air-tight container loaded with inoculated culture plates. The candle is extinguished by closing the container with its lid to g 8.101 Candle jar obtain the required atmosphere.  Practical Microbiology 24 Salient features: 1. Seitz filter is an example of sterilisation by filtration. 2. Filter disc is made up of asbestos (magnisium silicate) 3. Uses: For sterilisation of substances which get damaged by heat process ie sera, sugars, antibiotic solutions etc. Salient features: Fig 8.102 Seitz filter 1. Syringe filter is an example of sterilisation by filtration. 2. It contains the membrane which acts of as a filter. The common pore sizes membrane available are 0.2 or 0.22 and 0.45 um The smallest known um. Syringe filter syringe filter size is 0.02 um. Syringe 3. Membrane filters are made of cellulose Outlet esters. fluid 4. For sterilisation, syringe filled with The is fitted with the membrane filter. filter along with Syringe fluid is forced through the membrane by Fig 8.103 Syringe pressing the piston of the syringe. Ine tluid comes out from the other ena filter (outlet) volume S. Uses: (i) For filtration of small for removal of bacteria. d To remove particles from (1) to HPLC. Sample prior Salient features: with particles 1. N-95 mask filters 1 um efficacy of 95%. personne 2. It can be used by medical tted by to prevent the diseases transm droplet nuclei. orking 3. It is useful wheuen influenza with especially M.tuberculosis, H1N1 8.104 N-95 mask Pig virus, Swine flu virus. p o t s 125 Salient features: 1. Chorioallantoic membrane (CAM) of chick embryo is used to certain grow viruses. 2. Variola and vaccinia viruses Fia.8.105 Pocks on chorio allantoic membrane produce pocks on the CAM. Salient features: 1. Use: To detect antibiotic sensitivity pattern of bacteria. 2. Nutrient agar is generally used. 3. Antibiotic discs are applied. 4. Control strain is also inoculated along with test strain. Fig. 8.106 Stoke method of antibiotic sensitivity testing Salient features: 1. Use: To detect antibiotic sensitivity pattern of bacteria. 2. Antibiotic discs are used. inoculated. 3. Control strain is not Fig. 8.107 Kirby-Bau method of antibiotic sensitivity testing 26 ractical MicrobioloE Salient Features: 1. Epsilometer or E-test antimicrobial is 256 192 test to detect sensitivity 128- 96 inhibitory minimum 64 48 (MIC) concentration of antibiotic. 32 2. It is a modification of 24 the 16 agar dittusion sensitivity 12 E-test strip test. 3. This test uses an absorbent Bacterial growth strip with a known gradient 192 Z8 of antibiotic concentration Zone of Inhibition 1.0 along its length..75.50 4. This strip is placed on the agar plate inoculated MIC point.19 with the test organism, the.125| antibiotic diffuses into the.094- 064 medium. 25 F.047.032- 5. The MIC is recorded as the 023 lowest concentration of the MIC 2 mg/l F016 gradient which inhibits the (a) (b) growth of the organism. Fig. 8.108 (a) Epsilometer or E-test on the agar plate (b) Details of E-test strip Essential Points to Remember 1. Practise to identify the spots. 2. Student should be prepared with questions related to each spot.