Gram positive cocci. Staphylococci and streptococci

1. GRAM POSITIVE COCCI STAPHYLOCOCCI AND STREPTOCOCCI

LECTURE №8
GRAM POSITIVE COCCI
STAPHYLOCOCCI AND STREPTOCOCCI

2. RESPIRATORY INFECTIONS

Respiratory infections are diseases that
transmitted mainly by airborne way and by
dust. At the reception of a dentist, respiratory
infections are one of the most frequently
transmitted groups of infections, an aerosol
formed during the operation of drills, turbines
easily contaminate surrounding objects and
enter the respiratory tract.

3. MOST IMPORTANT PATHOGENS

The most important pathogens of
respiratory infections are pathogenic
cocci, which is an extensive group
including gram+ and Gram- cocci that
cause purulent inflammatory processes
of different localization (also called
pyogenic).

4. COCCI

A
coccus
(plural
cocci)
is
any bacterium or archaeon that has a
spherical, ovoid, or generally round
shape
Cocci may occur as single cells or remain
attached following cell division

5.

6. STAPHYLOCOCCAL INFECTION

Staphylococcal infection is a collective
concept that unites infectious diseases
caused
by
staphylococci.
It
is
characterized by purulent inflammation
of any organs and systems with a
tendency to progressive spreading,
generalization and septic flow.

7. STAPHYLOCOCCAL INFECTION

Staphylococcus can take part in mixed
purulent processes of the maxillofacial area,
stand out as a cop of microbial associations in
abscesses, phlegmon, osteomyelitis and
stomatitis. In dental hospitals and private
clinics there is often a nosocomial
staphylococcal infection after surgical
interventions on the dentoalveolar system and
the paranasal sinuses.

8. STAPHYLOCOCCUS

Staphylococcus is a genus of Gram-positive
round bacteria that form in grape-like clusters
Aerobes or facultative anaerobes
The Staphylococcus genus includes at least 40 species.
Of these, nine have two subspecies, one has three
subspecies, and one has four subspecies
Most are harmless and reside normally on
the skin and mucous membranes of humans and
other organisms
Staphylococci are ubiquitous microorganisms that
cause various purulent-inflammatory processes in
humans and animals (they are also called pyogenic)

9. STAPHYLOCOCCUS

Staphylococci belong to the department of
Firmicutes, this family. Micrococaceae, genus
Staphylococcus. The genus includes 27
species, among which there are pathogenic,
conditionally
pathogenic
species
and
saprophytes. The main human lesions are
caused by 3 species: S. aureus, S.epidermidis
and S. saprophyticus.

10.

Staphylococcus aureus
(Gram stain)
http://www.meteoweb.eu/2016/03/il-diabete-aumenta-il-rischio-di-contrarre-gravi-infezioni-del-sangue/649580/

11.

Staphylococcus epidermidis
(Gram stain)

12.

Staphylococcus saprophyticus
(Gram stain)

13. MORPHOLOGY

Staphylococci
have
a
spherical shape (round
cells are called cocci). In
preparations from pure
culture they are arranged
in the form of disordered
clusters
resembling
bunches of grapes. In
smears from pus - singly, in
pairs or in small groups. Do
not have a dispute, flagella
(immovable), can form a
gentle capsule.

14. TINCTORIAL PROPERTIES

Gram-positive
Staphylococcus aureus
(Gram stain)

15. CULTURAL PROPERTIES OF S. AUREUS

Facultative anaerobes
Are not demanding for nutrient media
On dense media form colonies in S-form round, with an even edge, painted in
cream, yellow, orange
On liquid media give a uniform turbidity
They grow on saline media (5-10% NaCl)
Milk-salt and yolk-salt agar are elective
media for staphylococci

16.

17. BIOCHEMICAL PROPERTIES

Saccharolytic: ferment 5 carbohydrates of
Hiss's medium to acid
Proteolytic: ferment proteins with the
formation of H2S, liquefy gelatin in the
form of a funnel, for 4-5 days the funnel is
filled with liquid

18. STAPHYLOCOCCUS ANTIGENIC STRUSTURE

Staphylococci have about 30 antigens:
proteins, polysaccharides, teichoic acids;
many extracellular substances that form
staphylococci have antigenic properties.

19. FACTORS OF PATHOGENICITY

Exotoxin (released outside, outside the cell), consisting
of several fractions: hemolysin (destroys erythrocytes),
leukocidin (destroys leukocytes), lethal toxin (kills
rabbits), necrotoxin (causes skin necrosis in rabbit with
intradermal administration), enterotoxin (causes food
poisoning), exfoliatin (causes pemphigus in newborns syndrome of "scalded skin")
Enzymes of aggression: hyaluronidase (destroys
hyaluronic acid), plasmocoagulase (coagulates blood
plasma), DNAse (destroys DNA), lecithovitellase
(destroys lecithin), fibrinolysin (destroys fibrin clots)
W. E. Sause et al Antibody-Based Biologics and Their Promise to Combat Staphylococcus aureus Infections.
Trends in Pharmacological Sciences. Volume 37, Issue 3, p231–241, March 2016

20. RESISTANCE

Staphylococci are resistant to
external environment, but sensitive
to des. solutions, especially to
diamond green, are often resistant to
penicillin.
form
an
enzyme
penicillinase.

21. EPIDEMIOLOGY OF STAPHYLOCOCCAL INFECTIONS

Staphylococci are ubiquitous and are often found in
normal human microflora (carriers). Staphylococcus
aureus colonizes the nasal passages, abdominal cavity,
axillary regions. Epidermal staphylococcus occupies the
smooth skin, the surface of the mucous membranes.
Saprophytic staphylococcus occupies the skin of the
genitals, the mucous membrane of the urinary tract.
Most infections are endogenous and the infection is
associated with the transfer of the pathogen from the
places of colonization to the traumatized (damaged)
surface.

22. EPIDEMIOLOGY OF STAPHYLOCOCCAL INFECTIONS

Staphylococcal infections are called plague of the 20th
century, i.e. they are dangerous and very common,
especially in maternity hospitals, in surgical
departments.
1) source of infection - a sick person or a healthy
carrier;
2) the transmission mechanism is mixed;
3) transmission ways: airborne, airborne, contact, food;
4) susceptibility of the population - susceptibility
depends on the general condition and age; The most
susceptible are newborns and infants.

23. PATHOGENESIS AND CLINIC OF DISEASES

Entrance gate - any organ and any fabric; Staphylococci
penetrate through damaged skin, mucous membranes
of the mouth, respiratory tract, genitourinary system,
etc.
Staphylococci reproduce at the site of penetration,
form exotoxin and enzymes of aggression and cause
the formation of local purulent-inflammatory foci.
Propagating from these foci of staphylococci can enter
the blood (sepsis), and with blood - into other organs
(septicopyemia).
The incubation period is from several hours to 3 to 5
days.

24. PATHOGENESIS AND CLINIC OF DISEASES

Staphylococci cause more than 100 nosological forms
of diseases. They affect the skin (furuncles,
carbuncles), subcutaneous fat (abscesses, phlegmon),
respiratory tract (tonsillitis, pneumonia, sinusitis),
cause mastitis, purulent myositis and muscle
abscesses, brain abnormalities after traumatic brain
injuries, endocarditis, affect bones osteomyelitis,
arthritis), affect the liver, kidneys, urinary tract
(pyelonephritis, cystitis). Especially dangerous are the
diseases when staphylococci enter the blood (sepsis)
and affect internal organs (septicemia). Staphylococcal
infections are accompanied by intoxication, fever,
headache.
Diseases are acute, but may also be chronic.

25. THE SYNDROME OF “SCALDED BABIES”

The syndrome of "scalded babies" is observed in
newborns. The disease begins violently,
characterized by the formation of large foci of
erythema on the skin with the formation of large
blisters (as in thermal burns) and the exposure of
wet eroded areas.

26. THE TOXIC SHOCK SYNDROME

The toxic shock syndrome was first
recorded in 1980 in women aged 15 to
25 years using tampons during
menstruation. It is manifested by high
fever (38.8° C and above), vomiting,
diarrhea, rash, drop in blood pressure
and development of shock, often leading
to death.

27. FOOD POISONING

Food poisoning is manifested by vomiting, watery
diarrhea within 2 to 6 hours after eating the infected
foods, usually confectionery products with cream,
canned food, meat and vegetable salads.
Manifestations disappear or significantly weaken in
24 hours even without treatment.

28. AN ALLERGY TO STAPHYLOCOCCAL TOXINS

It is often develops an allergy to
staphylococcal toxins, which leads to
long, chronic illnesses.

29. PYODERMA

Pyoderma means any skin disease that is pyogenic (has
pus)
Most common isolated organism was Staphylococcus
aureus
Pyodermas are a common cause of skin infection in
children and are associated with many multidrugresistant organisms

30. WHITLOW

A whitlow or felon is an infection of the tip of
the finger
A whitlow results from penetration of pyogenic
microbes into the soft tissues of the palmar surface of
the finger (as a rule, staphylococci, less often
streptococci, sometimes a mixed pathogenic microflora
is noted)

31. ACUTE TONSILLITIS

Acute tonsillitis (angina) is
an infectious disease with
local manifestations in the
form
of
acute
inflammation
of
the
components
of
the
lymphatic pharyngeal ring,
most often the palatine
tonsils
caused
by
streptococci
or
staphylococci, less often by
other
microorganisms,
viruses and fungi

32. DIAGNOSIS OF STAPHYLOCOCCAL INFECTIONS

Materials to be examined: pus, wounds
liquor, sputum, blood, vomit, food
Bacterioscopic,
bacteriological
and
biological methods are used
Serological reactions did not find
application

33. DIAGNOSIS OF STAPHYLOCOCCAL INFECTIONS

Bacterioscopic method
prepare a smear from pus, Gram staining
and microscopy; in the smear are visible
leukocytes, neutrophils, individual round
cells of staphylococci and disordered
clusters resembling a bunch of grapes
(blood is not prepared from a blood
smear)

34.

Gram stain of Staphylococcus aureus in pus

35. DIAGNOSIS OF STAPHYLOCOCCAL INFECTIONS

Bacteriological method
Isolate a pure culture by sowing the material on nutrient
media (more often on blood agar for detecting
hemolysis) and then conducting its identification - study
morphology (Gram stain), the presence of pathogenicity
factors
(plasmocoagulase,
lecithovitelase)
and
biochemical properties (anaerobic cleavage of mannitol
and glucose); the definition of an antibioticogram is
mandatory; staphylococci are representatives of normal
microflora, therefore, it is impossible to be limited by
the isolation and identification of the pathogen,
quantitative methods of analysis are neededdetermination of the number of microbes in the sample

36. DIAGNOSIS OF STAPHYLOCOCCAL INFECTIONS

Bioprobe (food poisoning)
infection of small suckling kittens, who get
vomiting and diarrhea in an hour and they
die

37. TREATMENT

Apply broad-spectrum antibiotics, semisynthetic
penicillins
(methicillin,
oxacillin),
sulfonamide
preparations
It is necessary to determine the antibioticogram
In recent years, patients have been isolated from
staphylococci, resistant to most chemotherapeutic
drugs. In such cases, antitoxic anti-staphylococcal
plasma or immunoglobulin obtained from the blood of
donors immunized with staphylococcal anatoxin is used
for treatment
When chronic forms of diseases are also introduced
staphylococcal anatoxin, use autovaccine.

38. PREVENTION

For specific prevention (planned surgical
patients, pregnant women), adsorbed
staphylococcal anatoxin can be used.
Nonspecific
prevention
is
more
important - it is compliance with sanitary
and hygienic rules, tempering the body