2. Report Overview:
Cocci
1. Staphylococci
a. Staphylococcus aureus
b. Staphylococcus epidermidis
c. Staphylococcus saprophyticus
2. Streptococci
a. Alpha hemolytic
b. Beta hemolytic
c. Gamma hemolytic
3. Cocci
A coccus (plural: cocci, meaning berries) is a spherical-shaped gram
positive bacteria. It is usually round but also comes as oval,
elongated, or flattened on one side.
4. Cocci
Cocci divide to reproduce, and they can remain attached to
one another after the binary fission.
7. ❑ Cocci that are divided into two planes and
remain in groups of four are known as
tetrads.
8. ❑ Those that divide in three planes and
remain attached in cubelike groups of
eight are called sarcinae.
9. ❑ Staphylococci are those that are divided in
multiple planes and form grapelike
clusters or broad sheets.
10. 1. Staphylococci
Staphylococcus (sometimes called staph) is a genus of
Gram-positive bacteria that can cause various infectious
disease in the different tissues of the body. Staph-related
illness can range from mild and requiring no treatment to
severe and potentially fatal.
The name Staphylococcus comes from the Greek word
“staphyle,” which means a bunch of grapes, and “kokkos,”
meaning berry.
11.
12. a. Staphylococcus aureus
It is called “aureus” because of its color, the word was derived from
the Latin word “aurum,” which means gold
It is a catalase positive and coagulase positive cocci
It is considered as the most important human pathogen
Its normal flora is commonly found in the anterior nares
Methicillin-resistant Staphylococcus aureus (MRSA) is one of its
strains that is found to be very difficult to treat because of its
resistance to the antibiotic methicillin
14. Rapid enzyme tests
´Rapid enzyme tests detect the presence of the following enzymes:
´(1) Catalase breaks down hydrogen peroxide.
´This test is used to differentiate the genus Staphylococcus (catalase-positive) from
Streptococcus (catalase-negative).
´ In general, many anaerobes (and some microaerophiles) do not make catalase
(2) Oxidase (cytochrome-C oxidase) is produced by most Gram-negative bacteria but
not by members of the Enterobacteriaceae. Oxidase-positive rules the latter out.
(3) Nitrate reductase reduces nitrate to nitrite.
It is used to detect the presence of Enterobacteriaceae in urine
a)Escherichia coli and other enterobacteria produce nitrate reductase; this test
requires that the bacteria remain in contact with the urine for a sufficient time.
b)Staphylococcus saprophyticus does not produce nitrate reductase.
21. b. Staphylococcus
epidermidis
It is the most common contaminant of lab samples and medical
devices.
Its normal flora is usually found on the skin and has a white pigment
It is catalase positive and coagulase negative
It is also sensitive (susceptible) to novobiocin.
It is a significant cause of bacterial sepsis
24. c. Staphylococcus
saprophyticus
It is a catalase positive and coagulase negative
novobiocin resistant
It has a bright yellow pigment or white pigment
S. saprophyticus is part of the normal human flora that colonizes the
perineum, rectum, urethra, cervix, and gastrointestinal tract.
28. 2. Streptococci
Streptococci bacteria got its name from the Greek streptos
(“chain”) + kokkos (“berry”)
Streptococci are gram-positive spherical bacteria. Unlike
staphylococci, streptococcal cells usually grow in chains.
Streptococci are catalase negative.
It is categorized as alpha-hemolytic, beta-hemolytic, and
gamma-hemolytic streptococci
29.
30. a. Alpha Hemolytic
1. Streptococcus pneumonia
▪They are optochin sensitive
▪It is “lancet” shaped
▪Quellung reaction positive: capsular swelling
▪May appear as small, grey, moist (sometimes mucoidal)
36. II. Viridans Streptococci
▪Viridans streptococci are part of a normal oral flora
▪It is catalase negative
▪Resistant to optochin
•The term viridans derives from the Latin word viridis,
meaning “green”
48. Enterococci Group:
Enterococcus faecalis & Enterococcus faecium
▪Common cause of nosocomial infections
▪Can grow in bile
▪ Can grow in 6.5% NaCl
▪Often grouped in pairs (diplococci)
▪Normal flora: GI Tract
▪Found in feces
c. Gamma Hemolytic