INTRODUCTION Actinomycetes are those groups of bacteria which are thin and have cell wall made up of muramic acid. Their nuclei are prokaryotic and are susceptible to antibacterial antibiotics. They look similar to fungi superficially as they form branching filaments. They are related to mycobacteria and corynebacteria. Image source: slideplayer They are Gram-positive, non-sporing, non-motile, … Read more
INTRODUCTION OF ANTIGENS Antigens are any substance which when introduced into the body parenterally can induce the formation of an antibody with which reaction occurs specifically and in observable manner. It can also be defined as any substances that gets identified or recognized by B cell receptors (Ig) and T-cell receptors (along with the major … Read more
Introduction Smallest micro organisms Free living in nature Can grow in cell free medium Causes human infection M. pneumoniae: Pneumonia Ureaplasma urealyticum: non-gonococcal urethritis M. hominis and M. gentalium: genital tract infections. Cell wall absent Highly pleomorphic in nature Has no fixed shape and size Absence of cell wall precursors that are Muramic acid diaminopimelic … Read more
Introduction The combination of antigens (Ag) and antibodies (Abs) occur specifically and in observable manner. There is various usefulness of this type of reaction. Some of them are: A basis for the formation of antibody mediated immunity Helps generally during the cases of infectious diseases. Besides, in tissue injury related to some types of hypersensitivity … Read more
Introduction Formerly known as Pasteurella pestis. Falls in family enterobacteriaceae. Discovered in Honkong in 1894 AD by Yersin and Kitasato. Important medical species are Y.pestis, Y. pseudotuberculosis and Y. enterocolitica. Y. pestis responsible for causing plague whereas Y. pseudotuberculosis is a primary pathogen of rodents. Similarly, Y. enterocolitica causes enteric and systemic diseases. These diseases … Read more
S.N Anthrax Bacilli S.N Anthracoid Bacilli 1. All are non-motile. 1. Generally, are motile. 2. Presence of capsule. 2. Absence of capsule. 3. Growth occurs in long chain form. 3. Growth occurs in short chain form. 4. Medusa head colony in nutrient agar. 4. Medusa head colony absent. 5. Growth in penicillin agar is not … Read more
S.N Streptococcus pneumoniae S.N Viridans streptococci 1. Are capsulated. 1. Are non-capsulated. 2. Shape is lanceolate or flame shaped. 2. Shape is oval or round cells. 3. Give Positive quellung test. 3. Give negative quellung test. 4. On blood agar, dome-shaped initially, later on appear as draughtsman colonies. 4. On blood agar, dome-shaped. … Read more
S.N Flagella S.N Pili 1. These are helical structures but are not straight. 1. These are non-helical structures but are straight. 2. These are long whip like filamentous structures. 2. These are short hair like, filamentous, and tubular microfibers. 3. Comparatively thicker than pili. 3. Comparatively thinner than flagella. 4. Diameter of flagella is 10-30 … Read more
S.N Pili S.N Fimbriae 1. These are fine hair-like microfibers. 1. These are tiny bristle-like fibers. 2. These are longer than fimbriae. 2. These are shorter than fimbriae. 3. These are less in number. 3. … Read more
Introduction A condition resulted by the action of antibodies or immunologically competent cells. Cause structural or functional damage of the normal components of the body. Literally means ‘protection against self’ but means ‘injury to self’ in actual. Ehrlich postulated the concept of horror auto-toxicus. Was proposed while observing goats producing antibodies against erythrocytes from other … Read more