in this slide fully deals with Staphylococci infection. And also it deals with morphology, epidemiology, pathogenic, prevention and treatment of Staphylococci infection. In morphology, it differentiate the cultural plates of pathogenic and non pathogenic Staphylococci organisms.

1. Presented by
Dr.N.MAHALAKSHMI., M.Sc., M.Phil., PhD
Guest Lecture in BDU, P.G. Extention centre
Perambalure

2.  Gam positive cocci arranged in grap- like clusters
 Ubiquitous in nature
 Most common cause of suppurative lesions in
humans
 Potential pathogen due to its ability to develop
anitibiotic resistance
 1871- Von Recklinghausen first observed
Staphylococci in human pyogenic lesions

3. Continu…….
 1880- Pasteur isolated in liquid cultures from
pus and produced abscess by inoculating into
rabbits
 1880- Alexander Ogston (Scotland
surgeon)named Staphylococci
 Greek world : Staphyle – Bunch of grapes:
kokkos – berry
 Pathogenic Staphylococci produce golden
yellow colonies
 Non – pathogenic Staphylococci - white
colonies

4.  Gram positive cocci:
 In singles, pairs or irregularly as grape-
like clusterive ans.
Facultative anaerobe
Catalase positive bacteria
Comprised 40 species and subspecies
today

5.  Family – Micrococcaceae
 Genus – Micrococcus and Staphylococcus
 Species – Staphylococcus aueus, S. citreus,
S.albus ect…

6.  Divided into 2 sub- groups: Enzyme coagulase
1. Coagulase Positive Staphylococci
2. Coagulase Negative Staphylococci (CONS)

7. 1. Coagulase Positive Staphylococci:
Staphylococcus aureus – Rosenbach – 1884
Staphylococcus intermedius
Staphylococcus hyicus

8. 2. Coagulase Negative Staphylococci (CONS)
Staphylococcus albus (Staphylococcus epidermidis) -
1884 - Rosenbach
Staphylococcus citreus –Passet – 1885
Staphylococcus saprophyticus
Staphylococcus hominis,
Staphylococcus capitus,
Staphylococcus hemolyticus,
Staphylococcus lugdunensis

9.  Devided into S. aureus subsp aureus
S. aureus subsp anaerobius
Morphology
 Spherial cocci 1µm in diameter, arranged in a
grape like clusters
 Cluster formation – cell division in 3 planes with
daughter cells in close proximity
 Non –motile, non-sporing, mostly small amount
of capsular material seen in non-capsulated bacteria

11.  Grow readily on ordinary media
 Optimum: 37°C, pH 7.4-7
 Aerobe and Facultative anaerobe
 Nutrient agar: large 2-4mm, circular, convex,
smooth, opaque an easy emulisifiable
 Most strain produce golden yellow pigment, some
also white (creamy), orange or yellow pigments.
 Pigment production is enhanced with 1% Glycerol
monoacetate or milk
 Pigment : Lipoprotein allied to carotene
 Agar slope : Confluent growth – “Oil paint
apperance”

12. Blood agar:
Hemolytic or non-hemolytic colonies
Most strains incubated with 20-25% CO2 are hemolytic
Which is marked on Rabbit or sheep blood
Human blood – antibiotic or inhibitors
Mac Conkey’s medium:
Very small pink lactose fermenting colonies
Liquid media: Uniform turbidity
Selective media:
It can tolerate 5-10% NaCl, LiCl, Telluritr & Polymyxin
Ludlam’s media – Lithium chloride & Tellurite
Mannitol salt agar
Milk salt agar or broth -810%NaCl
Baird –Parker agar: agar containing Plymyxin B
Primary isolation: Sheep Blood Agar Plate (S-BAP)

15.  Indole test : -ve
 Urease test : + ve
 Methyl Red test : + ve
 Voge- Prausker test : + ve
 Catalase test : + ve
 Modified oxidase test : -ve
 Urea hydrolysis test : + ve
 Gelatin liquefaction test : + ve
 Lipolytic –dense opacity on egg agar
 Phosphatase test : + ve (phenolphthalein
diphosphate on nutrient agar – exposed to ammina
vapour –turn pink color due to free Phenolphthalein)

16.  Coagulase positive
 Ferment mannitol
 Clear hemolysis on Blood agar
 Golden yellow pigment
 Liquefy gelatin ; Produce phpsphatase
 Potassium tellurite medium: Blackcolonies

17. PENICILLIN RESISTANCE - 3types:
 Betalactamase production – Penicilinase
A,B,C,D
 Changes in baccterial surface receptors binding
of beta lactam antibiotics
 Development of tolerance to penicillin

18. 2 types of diseases
Infections
Intoxications
A number of Staphylococcal factors, both
cell
associated and ectracellular, have been identified,
which may influence virulence.
A. Cell wall associated polymers
B. Cell surface proteins
C. Toxins
D. Extracellular enzymes

19.  Polysaccharide peptidoglycan
 Teichoic acid
 Capsular polysaccharide

20.  Half of the cell wall weight is peptidoglycan
 Subunits of peptidoglycan is N-Acetly
muramic acid (NAM) and N- Acetly
Glucosamine (NAG)
 Unlike gram negative cell wall- Gram positive
cell wall has many cross- linked bridging
layers which makes the cell wall more rigid
(RIGID CELL WALL)

21.  Species – specific Phosphate containing
polymers
 Bound covalently to peptidoglycan layer or
through lipophobic linkage to the cytoplasmic
membrane (Lipo-teichoic acid)
 It mediates attachment to mucosal surfaces
through its specific binding to Fibronectin

22.  Commonly believed to be found in-vivo
 Occasionally found when cultured in-vitro
 11 cpsular serotypes identified in Staphylococcus
aureus.
 Serotypes 5 or 8 –accounts for major infection
 Protects by inhibiting chemotaxis and
phagocytosis by polymorphonuclesr
leukocytes

23.  Protein A
 Clumping factor

24.  Surface of Staphylococcus aureus But not CONS
is specially coated with Protein A- covalently
linked to Peptidoglycan layer.
 Has a unique affinity for binding Fc receptor
of Immunoglobulin IgG. Protein -A detection
is one of the specific test to detect
Staphylococcus aureus .
 Protein –A coated Staphylococci used as non-
specific carrier of antibodies directed against
other antigens like Streptococci (Serology: Co-
agglutination test).

25. Another surface proteins, is the
“bound coagulase” which is responsible for the
slide coagulase test

26.  Alpha toxin, beta toxin, delta toxin, gamma toxin
 Panton –Valentine toxin
 Exfoliative toxins A,B (Exfoliative dermatitis /
Staphylococcal Scalded Skin Syndrome SSSS,
Food poisoning – preformed toxin 2- hr, self
limiting)
 Super antigens:
 Enterotoxins – 8 (A-E, G-I)
 Toxic Shock Syndeome Toxin (TSST-1) – super
antigen- activates a number of T cells

27.  Coagulase Reacting Factor (CRF) in plasma
 Clumping factor (Bound coagulase) on the
outer surface
 Binds Fibrinogen - converts it into insoluble
fibrin – clumping or aggregates.
 primary test in identifying Staphylococcus
aureus
 Other : Collagen binding protein, Elastin
binding protein, Fibronectin binding protein

28.  Coagulase : Trigges blood clotting
 Hyaluronidase: breaksdown Hyaluronic acid-
enables the bacteria to spread between cells
 Staphylokinase : Dissolves fibrin threads in
blood clots- allows to free itself from blood
clots
 Lipase : Digests lipids – allow them to grow
on skin surfaces and in cutaneous oil glands
 Beta lactamase: breaks down penicillin –
resistant to beta lactam antibiotics like
penicillins and Cephalosporins

29.  Skin and soft tissue infections: Folliculitis,
furuncle (boil), Abscess Particlarly breast
abscess), wound infection, carbuncle,
impetigo, paronycjia, less often cellulitis.
 Musculoskeletal: Osteomyelitis, Arthritis,
Bursitis, Pyomyositis
 Respiratory : Tonsillitis, Pharyngitis,
Sinusitis, Otitis, Broncho-pneumonia, Lung
abscess, Empyema, Rarely pneumonia

30.  Central nervous sytem:
abscess, Meningitis,
Intracranial
thrombophlebitis
 Endovascular:
Bacteremia, Septicemia,
Pyemia, Endocarditis
 Urinary : Uncommon un
UTI, S.saprophyticus –
females common
(Novobiocin resistant)

31.  Primary parasites of humans
 Colonise skin glands and mucus membranes
 Human patients and carriers – potent source of
infection
 Animals and inanimate objects -less important
 10- 30% healthy population –nasal carriers
 10% perineal carriers, 10% hair carriers
 5-10% Vaginal carriers

32.  It carriage starts early in life, colonisation of
the umbilical stump being very common in
babies born in hospitals.
 Shedders: these carriers disseminate large
numbers for prolonged period
 Cocci shed by patients – contaminate fomites
like Hand kerchiefs, bed linen, blankets –
persists for days – weeks
 Come from infected domestic animals such
as cows.

33.  Exogenous infection
 Endogeneous infection
 Mode of transmistion:
 Direct contact
 Indirect contact
 Dust
 Droplet nuclei infection

34.  Hospital acquired infection
 Multidrug resistant bugs
 MRSA –Methicillin Resistant Staphyloccus
Aureus
 Common cause of posoperative wound
infection
 Hospital strains – hospital environment
 Resistant – Beta lactam antibiotics as well as
antimicrobial agents
 penicillin

35.  Isolation of patients with open
staphylococcal lesions
 Detection of staphylococcal lesions
among surgeons, nurses and other
hospital staff and keeping them away
from work till the lesions are healed
 Following strict aseptic techniques in
theatres

36.  Specimen
 Microscopy
 Culture
 Identification

37.  Hand washing
 Chlorheximide sprays
 Mupirocin
 Vancomycin
 Linezolid
 Teicoplanin
 Ceftabipirole
 Ceftaroline