الفصل الثاني Flashcards
What are the staph. aureus disease?
- Surgical wound’s infection, the abscesses in many organs
- Endocarditis
- Gastroenteritis (food poisoning).
What are the Characteristics of staph. Aureus ?
Gram-positive cocci arranged in clusters, some single cells, pairs and
short chains , non- flagellated , non -motile and non -spore forming,
aerobic and facultative anaerobic .
What are the virulence factors of the staph . Aureus ?
Produce catalase and coagulase enzymes.
Potent toxins including (Alpha, beta, gamma and dalta) toxins act
on host cell membrane, and produce enterotoxins.
What are the treatments used for staph.aureus disease?
-penicillin and cephalosporins
In beta –lactamases “penicillinase “ producing strains ( resist to
penicillin ), (Methicillin, Nafcillin ,Oxacillin )
What Are the stap.epidermids diseases ?
Endocarditis on prosthetic heart valve
Prosthetic hip infection and
Neonatal sepsis.
What are the Characteristics of the staph. Epidermids ?
Gram-positive cocci arranged in clusters, some single cells, pairs and
short chains , non- flagellated , non -motile and non -spore forming,
aerobic and facultative anaerobic . And coagulase negative.
What are the virulence factors of the staph. Epidermids?
Produce biofilm which enhance organism adhesion to the surface
of the foreign body and to multiply there. This biofilm completely
cover the bacteria and protect it from the antimicrobial agent and the host defence mechanism
What are the treatments used for staph. Epidermids diseases ?
Vancomycin plus either rifampin or an aminoglycoside.
What are the diseases that caused by strept. Pyogens?
Streptococcal infections may be localized i.e. acute pharyngitis and
skin infections or
Systemic (involvement of deeper tissue and organs) such systemic
infection are life threatening.
What are the virulence factors of the strept. Pyogens ?
protein –F and protein M which aids in the attachment to host
cells.
Streptolysin O, Streptolysin S toxins and
streptococcal pyrogenic exotoxins mediate production of rash
(i.e. scarlet fever ) or multisystem effects that may result in death.
They were catalase – negative.
What are the characteristics of strept. Pyogens?
Gram-positive spherical to ovoid cells in chains of short to medium
length (4 to 10 cells)
What are the treatments for strept. Pyogens diseases?
Penicillin. ,
Other penicillins, cephalosporins, and tetracyclines are also active
against Strept. .
Patients allergic to penicillin are usually treated with erythromycin.
What are the diseases caused by strept. Pneumonia?
pneumonia and meningitis in adult and
Otitis media and sinusitis in children .
What are the characteristics of the strept. Pneumonia?
Gram-positive, lancet- shape cocci , occur in pairs (diplococci ) or short
chain .
What are the virulence factors of strept. Pneumonia?
Pneumococcal polysaccharide capsule retards phagocytosis .
Produce pneumolysin and neuraminidase .
What is the treatments used for strept . Pneumonia diseases? And the prevention?
Penicillin G
Vaccine contain capsular polysaccharide most frequently given for
patients older than 65 years or given to patients with compromised
immune system.
———-used in gaseous form for sterilizeing heat senstive objects
Ethylene oxide
————kill spores in 3 to 10 hours ,used to sterlize medical equipments
Gluteraldehyde
Numerate the physical methods of strilization ?Write uses for three
1-incineration -treat infectious waste burned to ashes at 870-980 c
2-moist heat -autoclave 121c for 15-20 m used for media and liquids
3-dry heat - oven for 1.5 to 3 hours at 160-180C for glassware ,oil,poders
4-filtration -for heat senstive objects (antibiotics solution ,toxic ,chemicals,vaccines)
5-ionizing radiation -used for disposibeles such as plastic syringes and cloves before use
Compare between sterlization and disinfection ?
Sterilization: Killing or removal of all living organisms (including spores)
from particular location or material
Disinfection: is killing of many but not all microorganisms, and the
bacterial spores may survive.
Numerate physical methods of disinfection ?
1-boiling- at 100C for 15m. Whitch kills vegetative bacteria
2- pasteurizing - at 63C for 30 m which kills food pathogen
3- non ionizing radiation - such as ultra violet light the organism must have a direct surface
Numerate Chemical methods of disinfection ?
1- alcohol- ethyl
2-aldehydes -formaldehydes , gluteraldehydes
3-halogens -chlorine and iodine
4-heavy metals
5-phenolic - cleaning Bench at cncetration 2% - 5%
6- quarternary ammonium compounds- in the laboratory
What are the factors influence the activity of the disinfection ?
1- type of organismes present 2- tempreture and ph of process 3-surface nature 4-amount of organics(pus,blood,mucase) 5-length of time incotact 6-type of water avalible 7-number of organsims presesnt 8-concetration of disinfaction
