Pathogen Flashcards
Pathogen
Pathogenicity
Endogenous
Vector
Virulence
Endotoxins
GRAM NEG BACTERIA
(lippoplysaccharide & thin peptidoglycan)
-pseudomonas
-e coli
Exotoxins
GRAM POS BACTERIA
(thick peptidoglycan)
-staphylococcus
-streptococcus
Emergence of Drug Resistant Microbes
-serum drug concentrations that are too low to kill pathogens contribute to the development of drug resistant microbes.
-minimum inhibitory concentrations (MIC) must be present to stop harmful bacterial growth
Examples that contribute to drug resistance patterns
- insufficient duration of therapy
- empiric therapy: tx of an infection b4 specific culture info has been reported or obtained
- prophylactic therapy : tx w/ antibiotics to prevent an infection
superbugs
-MRSA (methicillin resistant staphylococcus aureus)
-penicillin resistant streptococcus pneumoniae
-vancomycin resistant enterococcus
-mdr-tb
-c. dif
-acinetobacter baumannii
Up & Coming Superbugs
- C.Dif: produce entertoxin and cytotoxin
(toxin A and toxin B)
-these 2 toxins are responsible for the diarrhea and inflammation seen in infected pts
-oral flagyl or oral vancomycin are used to tx pathogenic c.dif
- Acinetobacter: lives on the skin and is prevalent in ICU
-is a frequent cause of nosocomial pneumonia, esp late onset ventilator associated pneumonia
MDR-TB
3 highest TB burden countries:
China
India
Russia
These account for 62%
MDR-TB v. XDR-TB
MDR-TB: resistant to isoniazid & rifampin (the two most powerful anti TB drugs)
XDR-TB: resistant to any fluoroquinolone and at least 1 of 3 injectable second line drugs (capreomycin, kanamycin, amikacin)
Factors that predispose a person to nosocomial infections
-severe or prolonged illness
-age (young + old)
-impaired immunity (cancer, chronic disease)
-immunosuppression (radiation, steroids, chemo)
-antibiotics
-invasive procedures
-surgery
-burns
-lengthy hospital stay
Standard Precautions
incl a group of infection prevention practices that apply to ALL pts, regardless of infection.
Includes: hand hygiene, use of gloves, gown, mask, eye protection, face shield, safe injection practices
Airborne Precautions
prevent transmission of infectious agents that remain infectious when suspended in the air (rubeola - measles, chickenpox, TB). The preferred placement is in an airborne infection isolation room (AIIR). An AIIR is a single pt room that is equipped w/ special air handling and ventilation
Droplet Precautions
prevent transmission of pathogens spread thru close respiratory or mucous membrane contact w/ resp secretions. Incl (b pertussis, influenza, adenovirus, rhinovirus, n meningitis, group A strepto)
Contact Precautions
apply where the presence of excessive wound drainage, fecal incontinence, or other discharges from the body suggest an increased potential for extensive environmental contamination and risk for transmission.
Stages of Infection
Incubation Period
Prodromal Stage
Acute Stage
Convalescence
Incubation Period
-from the time the organism gains entrance into the host and:
-establishes itself
-spreads to target organs or tissues
-proliferates w/in various areas of the body
Prodromal Stage
-from the onset of nonspecific clinical manifestations (malaise, anorexia, HA):
-pathogen rapidly multiplying and spreading
-onset of specific clinical manifestations (sore throat, high fever)
-primary period of contagion
Acute Stage
-interval of maximum clinical illness:
-localized - specific focal point of infection
-systemic - involves entire body
Convalescence
-interval during which manifestations of infection resolve and disappear, which may take days, weeks, or months
