CORYNEBACTERIUM DIPHTHERIAE

Corynebacterium diphtheriae is a Gram-positive, non-spore forming, aerobic, rod-shaped and motile bacterium that causes diphtheria, an upper respiratory tract illness. They are pleomorphic organisms exhibiting different characteristic morphological shapes including V-shapes, irregular shapes and club-shapes.C. diphtheriae and other species in the genera Corynebacteria grow on the mucous membrane of the upper respiratory tract, skin, nares […]

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VIBRIO CHOLERAE

Vibrio cholerae is a Gram-negative, oxidase positive, spiral, non-spore forming, facultative, motile, curved or straight rod bacterium that causes severe diarrheal disease known as cholera in humans. Cholera, which is one of the leading causes of waterborne infections in developing countries, is a profuse watery diarrheal disease that is associated with extreme dehydration following excessive

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NEISSERIA GONORRHOEAE

Neisseria gonorrhoeae is a Gram-negative, oxidase-positive, non-motile, non-sporulating, non-capsulate, diplococcus found asymptomatically in humans. N. gonorrhoeae is found in the family Neisseriaceae and genus Neisseria which contains two important human pathogens viz: N. gonorrhoeae and N. meningitidis (which causes meningococcal meningitis, an inflammation of the meninges of the brain and spinal cord).  Though the syndromes

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MICROBIAL HAEMOLYSIS IN BLOOD AGAR

Haemolysis is the breakdown of red blood cells (RBCs). Certain bacterial species including Streptococcus and Staphylococcus species produce extracellular enzymes that lyse or breakdown the red blood cell component of whole blood. Such bacteria require additional growth factors for growth; and when such bacterial species are cultured in vitro in culture media (e.g. blood agar),

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Bacteriology, Biochemical Tests in Microbiology Lab, , ,

HISTORY OF ANTIBIOTICS – a synopsis on how it all started

Over the past 70 years, antibiotics have saved countless number of lives across the globe and enabled the further development of modern medicine as well as antimicrobial agents of diverse types with putative activity against pathogenic microorganisms. Despite the current state of antimicrobial resistance (AMR) globally, these antibiotics are currently used to counter the nefarious

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Pharmaceutical Microbiology, , ,

BACTERIAL ENZYMES THAT EXCITE PATHOGENICITY

Pathogenic bacteria produce numerous enzymes that help to increase their pathogenicity and/or virulence during an infection. These enzymes are extracellularly produced, and they are unique features of some pathogenic bacteria that help in their pathogenicity and virulence in their host. Extracellular enzymes help in the disease forming process of pathogenic bacteria even though they may

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Bacteriology,

EXOTOXIN PRODUCING BACTERIA

Exotoxins are extracellular toxins produced by living bacterial cells. They are protein molecules excreted by growing bacteria into the surrounding medium where the bacterium grows or into the tissues, cells and circulatory system of their human host. Exotoxins are diffusible in nature, and they are produced by both Gram-positive and Gram-negative bacteria. They are known

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