Streptococcus bovis- An Overview

Streptococcus bovis

What is Streptococcus bovis? Streptococcus bovis is a Gram-positive bacterium that belongs to the bovis/equinus complex of the viridans Streptococci. It is present in the gastrointestinal tract of humans as a normal inhabitant, along with other Streptococcus species. However, it is present in much fewer numbers than other such species. Previously S. equinus and S. bovis were considered as two …

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Staphylococcus hominis- An Overview

Staphylococcus hominis

What is Staphylococcus hominis? Staphylococcus hominis is a Gram-positive coagulase-negative member of Staphylococci that exists as a commensal on the human body, especially in the areas with apocrine glands, axillae, and the pubic region. Like most other coagulase-negative Staphylococci, S. hominis is also known to cause various nosocomial or hospital-acquired infections and may occasionally cause infection in patients with abnormally …

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Streptococcus agalactiae- An Overview

Streptococcus agalactiae

What is Streptococcus agalactiae? Streptococcus agalactiae is a Gram-positive, non-motile, non-spore-forming coccus that is the only member of the Group B of the Lancefield antigen grouping. It is a β-hemolytic, catalase-negative, facultative anaerobe that consists of ten different serotypes, separated on the basis of the immunologic reactions of their capsular polysaccharide. Because it is the only species present in the …

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Staphylococcus capitis- An Overview

Staphylococcus capitis

What is Staphylococcus capitis? Staphylococcus capitis is a Gram-positive, coagulase-negative coccus, present as a part of the human normal flora mostly localized in areas around the scalp and face that have been lately associated with bacteria in neonates. Staphylococcus capitis is a coagulase-negative Staphylococci with documented potential for both human disease and nosocomial spread. It is non-motile, non-spore-forming facultatively anaerobic …

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Staphylococcus epidermidis- An Overview

Staphylococcus epidermidis - An Overview

What is Staphylococcus epidermidis? Staphylococcus epidermidis is a Gram-positive bacterium belonging to the genus Staphylococcus and is the most frequently isolated species from human epithelia. Staphylococci are known as clustering Gram-positive cocci, nonmotile, non-spore-forming facultatively anaerobic that classified into two main groups, coagulase-positive and coagulase-negative. S. epidermidis belongs to the group of coagulase-negative staphylococci (CoNS), which is different from coagulase-positive …

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Enterobacteriaceae Cultural Characteristics

Enterobacteriaceae Cultural Characteristics

Image Source: Cole-Parmer Instrument Company. Cultural Characteristics of Citrobacter freundii Citrobacter freundii on Nutrient Agar Smooth, convex, translucent, or opaque grey colored with a shiny surface and entire margin; mucoid or rough colonies occasionally. Citrobacter freundii on Blood Agar Circular, flat, entire red colored colonies. Citrobacter freundii on Mac-Conkey Agar Pink colored after 24 hr incubation; pale-colored colonies turn pink …

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Bacterial Sizes, Shapes and Arrangement with Examples

Bacterial Sizes, Shapes and Arrangement with Examples

Bacteria are a type of biological cell that is prokaryotic and unicellular. Due to the lack of a membrane-bound nucleus, these are simpler than other types of living organisms. Although only some of them can be seen by naked eyes while the rest are microscopic, they display a wide range of shape, size, and structure. Bacterial Size Figure: The relative …

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Hemolysis of Streptococci- Types and Examples with Images

Hemolysis of Streptococci- Types and Examples with Images

Introduction A genus Streptococcus is a heterogeneous group of Gram-positive bacteria. Various streptococci are considered as the normal microbial flora of animals and humans, while some species under favorable conditions can also cause diseases ranging from sub-acute infection to acute or even chronic diseases/infections. Streptococci are spherical organisms that grow in chains because of incomplete separation after the division of …

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Gram-positive bacteria- cell wall, examples, diseases, antibiotics

Gram-positive bacteria

What are Gram-positive bacteria? These are bacteria whose classification has been based on their ability to retain the crystal violet dye after a brief wash with alcohol in the differential gram staining. Gram-positive bacteria stain purple while the Gram-negative bacteria stain Pink, after losing the purple color during the alcohol was thus taking up the safranin. Gram staining has been …

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Gram-negative bacteria- cell wall, examples, diseases, antibiotics

Gram-negative bacteria

What are Gram-negative bacteria? These are bacteria that define the opposite of the gram-positive bacteria in relation to the differential staining technique.  During gram staining, the gram-negative bacteria will lose the crystal violet dye color after a wash with alcohol and take up the pink/red color of the counterstain, safranin. The two classes of bacteria are differentiated through gram staining, …

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