Sexually transmitted diseases, e.g. syphilis Did you know
During 2013, there were 576 recorded incidences of syphilis in Ireland. The majority of cases occurred in males, with a male to female ratio of 16:1.
Vibrio (comma-shaped) Cholera
Classification by gram staining
Gram staining is a laboratory test used to differentiate between two bacterial groups: gram-positive bacteria and gram-negative bacteria.
These two bacterial groups have a different reaction to the stain used in this process. Knowing whether a bacteria is gram positive or gram negative can be important for doctors in determining appropriate treatment for humans who are infected with an unknown pathogenic bacteria. • If bacteria are gram positive they stain blue/purple.
• If bacteria are gram negative they stain pink.
Characteristics of gram-positive and gram-negative bacteria Gram positive
Gram negative
Structure Flagella
The cell wall is one thick layer No flagella
Reproduction Produces spores Resistance Examples
Low resistance to antibiotics Clostridium botulinum and streptococci
The cell wall contains two thin layers Has flagella
No spore-production
High resistance to antibiotics E. coli and salmonella
