Download Bacterial Diseases

Bacterial Diseases
Page 339: Table 25 – 1 & Table 25 – 2
Pathogenicity
• “the state of producing or being able to
produce pathological changes and disease”
Staphylococcus
(Page 342)
• “a genus of gram-negative, nonmotile,
opportunistic bacteria which tend to
aggregate in irregular, grape-like clusters”
• Implications for the Embalmer: page 343
Readings Question #1
• Staphylococcus aureus is the most pathogenic
of the staphylococci. What are its toxins
capable of doing? What enzymes does it
produce, and what is their known effect?
Staphylococcal Food Poisoning
• Page 343
• caused by ingesting an enterotoxin
• high resistance to heat, drying and radiation,
and high osmotic pressures
• inhabitant of nasal passages…contaminates
the hands…..readily enters food
• mechanical vectors
• mayonnaise, cream sauces
Skin and Wound Infections
• Page 344
• Sty: “infected follicle of an eyelash”
Skin and Wound Infections (cont’d)
• Pimple: infected hair follicle
• Abscess: more serious hair follicle infection
– furuncle/boil: superficial
– carbuncle: deeper
• Risk of underlying tissues becoming infected
• Toxemia: toxins circulate
Scalded Skin Syndrome
Toxic Shock Syndrome
• Page 344
Color Plates 39 and 40
• S. aureus growth associated with the use of a
new type of highly absorbent vaginal tampon
• swell with menstrual fluids and adhere to the
vagina
• tears in the vaginal wall
Streptococcus
Page 345
“spherical shaped bacteria occurring in chains”
What are the implications for the embalmer when
dealing with saprophytes?
Streptococcus pneumoniae
( pneumococcus)
• gram-positive ovoid bacterium
• cell pairs surrounded by capsule
• common cause of:
1) lobar pneumonia
2) meningitis
3) otitis media
Lobar Pneumonia
• Page 346
• Readings question #2:
• What is lobar pneumonia, and how is it
characterized?
• What are some of the predisposing conditions
for this disease?
• penicillin and fluoroquinolones
Meningitis
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Figure 25-1 Page 346
70% of the population are healthy carriers
Gram-positive encapsulated diplococcus
Leading cause of bacterial meningitis
Most cases between 1 month and 4 years
Broad-spectrum cephalosporins
CSF obtained by a spinal tap
Vaccine: Pneumococcal Conjugated Vaccine
Otitis Media
• 85% before 3 years of age (Eustachian Tubes)
Streptococcus pyogenes
• Page 348 Color Plates 43 and 44
• Scarlet Fever: streptococcal pharyngitis
• Septic Sore Throat: respiratory secretions
– penicillin
• Puerperal Sepsis: Childbirth/Childbed Fever
• Rheumatic Fever: arthritis and fever
– 50% inflammation of the heart
– penicillin
– Syndenham’s chorea (St. Vitus’Dance)
Clostridium
• Page 351
• obligate anaerobes
• rod-shaped cells that contain endospores
• Clostridium botulinum: botulin
• Note the bullet points on page 351!!
Readings Question 3
(Page 352)
• Clostridium tetani causes what bacterial
infection? Describe the characteristics of this
microbe. Where is it found? What are its
symptoms, and what causes them?
Clostridium perfringens
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Pages 352 and 353
gram-positive, endospore-forming anaerobe
saprophyte
responsible for:
– Gas gangrene
– Tissue Gas (post-mortem)
– Food Intoxication
Gas Gangrene
Gas Gangrene
Readings Question #4
Clostridium perfringens is the causative agent of
a postmortem condition known as tissue gas.
What factors may result in this condition in the
decedent?
Food Intoxication
• Clostridium perfringens Gastroenteritis: one
of the more common forms of food poisoning
in the United States
• improper handling of meat during the
slaughtering of animals
• 2 main causes: 1) keeping foods warm for
more than 20 minutes
2) inadequate refrigeration
Clostridium difficile
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Spore-forming, gram-positive, anaerobe
Produces 2 exotoxins (toxin A and toxin B)
Found in enterics
Mode of transmission: shed in feces
Reservoir: anything that can be contaminated
with feces (including embalming tables!)
• Healthcare workers who touch “fomites” can
transmit these spores
Clostridium difficile
• Symptoms: watery diarrhea, fever, loss of
appetite, nausea, abdominal pain/tenderness
• Common cause of antibiotic-associated diarrhea
(AAD) (15-25% of all cases)
• Responsible for: psudomembranous colitis
(PMC); toxic megacolon; perforations of the
colon; sepsis; death (rare)
• Risk factors: antibiotic exposure; G-I
surgery/manipulation; lengthy stay in healthcare
settings; serious underlying illness;
immunocompromised; elderly