Staphylococcus 2017, Dr.Babiker Saad Almugadam Yousif, University of El Imam El Mahdi, Kosti city, Sudan

1. Genus Staphylococcus
Almugadam B Saad
Lecturer of medical microbiology Full name
Babiker Saad Almugadam Yousif
Faculty of medical laboratory sciences
University of El Imam El Mahadi
Kosti-Sudan
MSc University of Khartoum
BSc University of El Imam El Mahadi
Babiker Saad Almugadam Yousif

2. Genus Staphylococcus
With the end of this topic , You should
know the following:
Learning
objectives
1-Important properties , M.Important
species , Pathogenesis , Lab diagnosis
,and drugs of choice for Staphylococcus
2-How to differentiate between the
species of staphylococcus

3. Scientific classification
Kingdom: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Staphylococcaceae
Genus: Staphylococcus
Medical Important Species
1-S.aures (Staphylococcus pyogen)
2-S.saprophyticus (Subgroup VI Staphylococci)
3-S.epidermidis (Staphylococcus Albus)

4. - Gram+ve cocci arrange in
grape like cluster , Non
motile , Non sporing ,
General Characters of
Staphylococcus
motile , Non sporing ,
Facultative anaerobe ,
Catalase positive , Resist
bile salt , some species
produce pigment , Some
strain of S.aures capsulated.

5. Factors Influencing Pigment Production :
1. Temperature: Maximum
pigmentation at RT (20° to 25°C).
2. Oxygen: pigmentation
under aerobic condition.
3. Medium: Pigment is
produced on solid medium.
4. Light: pigmentation is
better in presence of light.
Golden pigment of
S.aureus

6. Classification of Staphylococcus
A. Baird-Parker classification : classify staphylococcus into subgroups (I-VI).
B. On the basis of pathogenecity:
1. Pathogenic species
2. Non-pathogen species
C. On the basis of coagulase production:
1. Coagulase positive staphylococci (CPS)1. Coagulase positive staphylococci (CPS)
2. Coagulase negative staphylococci (CNS)
D. On the basis of pigment production :

7. Pathogenesis
A. Staphylococcus aureus :
-Virulence Factors :
Hemolysin , Leucocidin , Enterotoxin , Fibrinolysin
(staphylokinase) , Exfoliative toxin , Toxic shock syndrome
toxin (TSST) , Nucleases , Lipases , Proteases , Teichoic acid ,
Capsule , Protein A , coagulase Hyaluronidase , Bactermia ,
Catalase ,B.lactamase , and Scarlatina toxin.Catalase ,B.lactamase , and Scarlatina toxin.
-Diseases :
1.Pyogenic :
- Cutaneous : Furuncles , styes , boils,abscess,carbuncles,
impetigo, pemphigus neonatorum.
- Deep infection: Acute osteomyelitis, tonsillitis, sinusitis,
pneumonia , pharyngitis , pulmonary abscess , breast
abscess,meningitis,endocarditis , septicemia and renal
abscess.

8. 2.Toxogenic :
food poisoning (Enterotoxin) , staphylococcal scalded skin
syndrome (Exfoliative toxin), toxic shock syndrome (TSST-1).
B. Staphylococcus Saprophyticus :
-Virulence Factors :
Catalase , B.lactamase and Teichoic acid .
-Diseases : UTI in sexually active young women
C. Staphylococcus Epidermidis :
-Virulence Factors :
Catalase , B.lactamase and Teichoic acid .
-Diseases : Endocarditis

9. Laboratory diagnosis
- Specimen: depend on the type and site of infection
- Microscopy : Gram+ve cocci , Arrange in grape like cluster .

10. Culture: Done in many culture media according to type and site
of infection .
On Nutrient agar:
1-S.aures : golden yellow ,
circular, smooth, easy emulsify .
2-S.saprophyticus : White colony
3-S.epidermidis : White colony
On Blood agar :
1-S.aures : beta hemolytic
2-S.saprophyticus : Non
hemolytic
3-S.epidermidis : Non
hemolytic Blood agar

11. On Mannitol salt agar:
1-S.aures : YellowColony ,
mannitol ferment
2-S.saprophyticus : Yellow
Colony , mannitol ferment
3-S.epidermidis : White or
pink Colony , Nonmannitol
ferment
On MacConkey agar :
1-S.aures : pink in color ,
lactose ferment (LF).
2-S.saprophyticus : LF , some
strains may not grow
3-S.epidermidis : LF

12. Selective Media : Made by adding of
1. NaCl ?
2. Lithium chloride ?
3. Tellurite ?
4. Polymyxin ?
Example of Selective Media :
Mannitol salt agar
Baird-Parker media
CHROMagar Staph.
Baird-Parker media
Baird barker agar
Baird barker agar

13. - Identification : Base on
- Colonial Morphology and staining reaction ?
- Biochemical reaction and Antibiotic susceptibility
Manual :
MSANovobiocinDNAseCoagulaseSpecies
MFSensitive+ve+veS.aures
MFResistant-ve-veS.saprophyticus
Non MFSensitive+ve/-ve-veS.epidermidis
Catalase test
Positive : active bubles
Negative : No active bubles
Tube method

14. DNase test :
Positive : clear area round the
colony.
Slide method {bound coagulase}:
Positive : Clumping with in 10 seconds
Negative : No clumping with in 10
seconds
colony.
Negative : No clear area
Novobiocin Sensitivity test :
Zone of inhibition : Sensitive
No zone of inhibition : Resistance

15. Automated system:
Semi automated : API staph
Full automated : Microscan ,
Phonex , VitekPhonex , Vitek
Vitek

16. Several latex agglutination test kits are
available to identify S. aureus based on
(the detection of clumping factor or
protein A) or detection of Ab against
techioc acid or leucocidin or enterotoxin) .
- Serology :
- Molecular : as PCR , Sequencing
-Typing of Staphylococci : as phage typing , Antibiogram

17. Treatment
- staphylococci species sensitive to penicillin , Vancomycin
,Macrolides , and Cephalosporins .
-MRSA sensitive to Vancomycin
-VISA and VRSA sensitive to Cephalosporins
MRSA Detection :
Phenotypic : Cefoxitin disc 30ug , Methcillin disc 5ug , methcillin stripPhenotypic : Cefoxitin disc 30ug , Methcillin disc 5ug , methcillin strip
, methcillin or oxacillin agar.
Genotypic : As PCR
VRSA Detection : ??????????