CLINICAL MICROBIOLOGY

        CLINICAL MICROBIOLOGY 

 

                          Introduction 

The science of microbiology is a study of microorganism and their activities, it is concerned with their (1)Form (2) structure (3) physiology (4) metabolism (5) identification and (6) reproduction. The microorganisms are classified as Protista. this class includes all unicellular organisms, which are characterized by their lack of Definite definite cellular arrangement as well as lack of differentiation of cells for specific metabolic function. the microorganism include in the Kingdom Protista are (1) Bacteria (2) Algae (3) Fungi and (4) Protozoa. the microorganisms classified as Protista may be further divided into (A) Prokaryotes and (B)Eukaryotes.

CLINICAL MICROBIOLOGY 

A:- The prokaryotic group (fig --2) it contains microorganism with a very simple cell structure. the cell is not bound by membrane and it does not contain cell defined cellular organelles (fig --3) the genetic materials lies as a single piece of double stranded DNA in the cytoplasm. it is not organised into chromosomes inside a nuclear membrane. the cell does not contain mitochondria but contains simple enzyme system. prokaryotes multiple by a simple dividing process, known as binary fission.

Examples :-

(1):- Bacteria 

(2):- Rickettsiae 

(3):- Chlamydia 

(4):- Mycoplasma 

(5):- Blue green algae. 

B:- The eukaryotes group (fig--2) it contains microorganisms with a complex cell structure similar to that of higher organisms. the genetic material of Eukaryotic cell is differentiated into chromosomes which are contained in a nuclear membrane to form a definite nucleus. this cell contains Complex enzymes systems, mitochondria and other organelles. the cell is able to make its own energy. eukaryotes multiple by mitosis. 

Examples:-

(1):- Protozoa 

(2):- Fungi 

(3):- Algae  (accept blue green algae).

NOTE:--

(1):- Viruses are are also classed as microorganisms, but they are differentiated from all cellular forms of life. a viral particle consists of a nucleic acid molecule, either DNA or RNA, enclosed in a coat (capsid) made up of protein.the capsid  protects the nuclear acid and it is replicated by the host's enzymatic system and governs the formation of specific viral proteins. mutation consists of formation of newly synthesized protein subunit and nuclic acid into mature viral particle. viruses infect a wide variety of specific plant and animal hosts as well as prokaryotes and one of the eukaryotes algae. 

(2):- Prions are infactitious organisms composed primarily of protein (fig- 2). prions are the cause of a number of disease in a variety of mammals. example of disease caused by prions include, 

bovine spongiform encephalopathy  (BSE, also known as "mad cow disease") in cattle and Creutzfeldt-jakob disease (CJD) in humans. all none prions disease affect the structure of the brain of other neural tissue and all are currently untreatable and universally fatal.

CLINICAL MICROBIOLOGY LABORATORY TESTS 

Although some microorganisms all beneficial and essential for life, Pathogenic  microorganisms cause infactitious diseases. patients with infectious disease may present with a variety of signs and symptoms. the direct signs of infection are diffused redness, serious or purulent discharge from wounds or mucous membranes and the accumulation of pus in body cavities or abscesses. when infection involves deep organs, the indirect signs observed are dysentery, Cough,increased sputum production and burning on urination, etc. the infectious process may extend beyond local confined and it may be indicated by General or systematic manifestations such as chills, fever, Flushing( vasodilation), and an increase in pulse rate.

The chief functions of the clinical microbiology laboratory are:-

(1):- identification of the infectious organism and

(2):- to assist physician in the diagnosis and treatment of patient with infectious disease.