Which test is used for identification of enteric bacteria?
Urease test It is commonly used to distinguish the genus Proteus from other enteric bacteria.
What is antigenic structure of Enterobacteriaceae?
The enterobacterial common antigen (ECA) is a carbohydrate-derived cell surface antigen present in all Gram-negative bacteria belonging to Enterobacteriaceae family. Biosynthetic pathways shared by ECA and LPS (endotoxin) suggest close connections between these antigens.
How are enteric bacteria distinguished?
Generally, a distinction can be made on the ability to ferment glucose; enteric bacteria all ferment glucose to acid end products while similar Gram-negative bacteria (e.g. pseudomonads) cannot ferment glucose.
What type of antigen is found on all enteric bacteria?
The H-antigen is a protein antigen based on flagellar structure (25). Enterobacterales is a bacterial order that is defined in part by the presence of an antigen known as enterobacterial common antigen (ECA) (26).
What is the difference between O and H antigen?
The O antigens are distinguished by their different chemical make-up. The H antigens are distinguished by the protein content of the flagella. Each O and H antigen has a unique code number. Scientists determine the serotype based on the distinct combination of O and H antigens.
Where do enteric bacteria live?
Enteric bacteria are bacteria that typically exist in the intestines of animals and humans. Enteric bacteria can be either harmless, such as gut flora or microbiota, or pathogenic, which means that they cause disease.
What are the two of the four features of bacteria in the family Enterobacteriaceae?
Enterobacteriaceae is a family of Gram-negative, facultatively anaerobic, non-spore-forming rods. Characteristics of this family include being motile, catalase positive, and oxidase negative; reduction of nitrate to nitrite; and acid production from glucose fermentation.
What does O and H antigen mean?
Serotypes are groups within a single species of microorganisms, such as bacteria or viruses, which share distinctive surface structures. The outermost portion of the bacteria’s surface covering, called the O antigen; and. A slender threadlike structure, called the H antigen, that is part of the flagella.
What are the differences between O and H antigen?
The key difference between O and H antigen is that O antigen is the outermost portion of the bacteria’s surface covering while H antigen is the slender threadlike structure that is part of the flagella. Antigens are generally used in serotype identification system for the bacteria.
