MICROBIOLOGY FOR STUDENTS (M4S)

1. Alternaria species 2. Fusarium species 3. Aspergillus fumigatus 4. Aspergillus flavus 5. Trichothecium species

Identification of fungi can be made through various ways. One of the methods include microscopy. Microscopy can be done directly from the specimen or culture in the laboratory culture medium. The fungi are cutured on the Sabouraud Agar and incubated at room temperature for several weeks and identified by Scotch tape preparation followed by Lactophenol Cotton Blue Stain . Here are some of the images that are identified on the basis of culture in laboratory by plate exposure method. Identification is based on the colonial morphology, conidiospores a nd morphology as view on the high power (40X) and low power (10X).

Short Review on Gardnerella, Serratia, Hafnia and Francisella Gardnerella Serratia Hafnia Francisella 1. Gardnerella 1.1 Habitat Normal Vaginal flora of human. May also colonize distal urethra of males. 1.2 Morphology Gram variable or gram-negative coccobacilli or pleomorphic rod 1-1.5um in diameter Saline wet mount reveals clue cells which are large squamous epithelial cells with numerous attached small rods Non sporing , non-motile 1.3 Culture Facultative anaerobes grow best at 35° C to 37° C but growth occurs between 25- 42oC Optimum pH 6-6.5 On Human Tween Blood Bilayer Agar (HBT), Pin point colonies Small, gray, opaque colonies surrounded by diffuse zone of beta haemolysis 1.4 Species Only one species i.e G. vaginalis 1.5 Mode of Transmission Infection caused by person’s endogenous strains 1.6 Diseases I. Bacterial vaginosis II. Urinary Tract Infections III. Bacteremia- extremely rare conditions 1.7 Bacterial vaginosis Most comm...

Preparation of different Stains and Reagent Used for the diagnosis of fungal infections 1. 10% a KOH Requirements: KOH pellets Prodecure  10 gm of KOH pellets is weighed.  Mixed with 100ml of distilled water. 2. 20% KOH Requirements: KOH pellets Procedure  20 gm of KOH pellets is weighed.  Mixed with 100ml of distilled water. 3. Giemsa Stain Requirements I. Giemsa Powder II. Methanol III. Glycerol Procedure  3.8 gm Giemsa powder is transferred to 500 ml brown bottle containing few dry glass beads.  250 ml of Methanol and same volume of Glycerol is mixed well.  The mixture is placed in water bath at 50-60 degree centigrade or at 37 degree centigrade for up to 2 hrs for complete dissolution. 4. Lactophenol Cotton Blue Requirements I. Methyl blue (Cotton Blue) II. Phenol Crystals III. Lactic Acid IV. Glycerol Procedure  0.04 gm of methyl blue is dissolved in 10 ml warm water.  10 gm of phenol crystals is added.  10 ml...