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Some of the common characteristics of Enterobacteria are: 1. Gram-negative. 2. Rod-shaped (usually short bacilli; about 1 â 5 Ξm). 3. Facultatively anaerobic. 4. Non-sporing. 5. Mostly motile with peritrichous flagella, ( most species in the genera Klebsiella and Shigella are non-motile). 6. CatalasRead more
Some of the common characteristics of Enterobacteria are:
1. Gram-negative.
2. Rod-shaped (usually short bacilli; about 1 â 5 Ξm).
3. Facultatively anaerobic.
4. Non-sporing.
5. Mostly motile with peritrichous flagella, ( most species in the genera Klebsiella and Shigella are non-motile).
6. Catalase positive, oxidase negative.
7. Both lactose fermenters and non-fermenter.
8. Usually, acid-producing.
9. Usually, nitrate-reducing.
10. Characteristic antigens are known as enterobacterial common antigens (ECA). The outer membrane (O), flagella (H), and capsule (K) are antigens in most enterobacteria.
1. Gram-negative intra-cellular diplococci. 2. Neisseria meningitidis (meningococcus) has a prominent polysaccharide capsule that enhances virulence through its complement inhibitory and antiphagocytic action. Nonencapsulated N. meningitidis isolates are generally considered nonpathogenic. The capsuRead more
1. Gram-negative intra-cellular diplococci.
See less2. Neisseria meningitidis (meningococcus) has a prominent polysaccharide capsule that enhances virulence through its complement inhibitory and antiphagocytic action. Nonencapsulated N. meningitidis isolates are generally considered nonpathogenic. The capsule is also the immunogen in the meningococcal vaccine.
3. Serogroups: Based on the antigenic nature of capsular polysaccharides, N. meningitidis can be typed into 13 serogroups (A-D, X-Z, 29E, W135, H-J, and L). Six serogroups (types) of Neisseria meningitidis A, B, C, W, X, and Y cause the majority of cases of IMDs worldwide.
Serotype A was the leading cause of epidemic meningitis worldwide, mainly in the African meningitis belt.