Bacillus cereus- An Overview

Bacillus cereus

Habitat of Bacillus cereus Bacillus cereus is isolated from soil, vegetables, milk, cereals, spices, fried rice, cooked poultry and meats, soups, and desserts. It is also found in mashed potatoes, beef stew, apples, hot chocolates sold in vending machines, and other improper food handling areas. In 1887, B. cereus was isolated from air in a cowshed by Frankland and Frankland. It …

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Staphylococcus lugdunensis- An Overview

Staphylococcus lugdunensis

What is Staphylococcus lugdunensis? Staphylococcus lugdunensis is a Gram-positive, coagulase-negative coccus that is a part of human normal flora but recently has been associated with various skin and soft tissue infections. S. lugdunensis has a significant pathogenic potential compared with other coagulase-negative staphylococci owing to its various virulence factors. Like all Staphylococci, S. lugdunensis is also clustering Gram-positive cocci, non-motile, …

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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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Morphology of Bacteria- Sizes, Shapes, Arrangements, 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 shapes, sizes, and structures. 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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