Transcript Haemophilus (Hib)

Mycoplasma
The smallest free-living organisms in
nature!
Mycoplasma pneumoniae
• Figure 26-1 “fried egg appearance” of colonies
• Page 376
• the most significant human pathogen among
the Mycoplasmas
• Readings question #1: Where do the
Mycoplasma pneumoniae colonies adhere?
How do they spread? What diseases are
caused by this bacterium?
Rickettsia
• Page 377
• only reproduce within a mammalian cell
• induce phagocytosis; enter cytoplasm;
reproduce by binary fission
Readings question #2: What is the most
severe rickettsial infection, and what organism
causes it?
Rocky Mountain Spotted Fever
Rickettsia prowazekii
• Readings question #3:
• How is the Rickettsia prowazekii microbe
transmitted to produce epidemic typhus?
• Signs and symptoms: high and prolonged
fever that lasts at least 2 weeks; stupor; rash
that darkens as disease progresses
• Anne Frank
Treatment
• tetracycline, doxycycline, chloramphenicol
• eliminate conditions
• vaccines for military
Rickettsia typhi
• Page 378
• sporadic
• murine: Latin for “mouse”
Readings question #4:
How is the Rickettsia typhi microbe transmitted
to produce endemic typhus?
• treatment: tetracycline, doxycycline,
chloramphenicol
• rat control is best preventive measure
Coxiella burnetti
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parasite of several arthropods
birthing: organisms shed in high numbers
resistant to heat, drying, & many disinfectants
inhaling a single pathogen can cause infection
pasteurization temperature raised in 1956
responsible for Q fever
Q (Query) Fever
• Wide range of clinical symptoms
• 60% asymptomatic
• Acute: high fevers (104-105 degrees), severe
headache, general malaise, confusion, sore
throat, chills, sweats, non-productive cough,
nausea, vomiting, diarrhea, abdominal pain
and chest pain
• pneumonia: 30-50% patients; hepatitis
Chronic Q Fever
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Infection persists for more than 6 months
1 year or 20 years
Endocarditis
Transplant recipients, cancer, kidney disease
Treatment: acute- doxycycline
chronic- doxycycline & quinolones
doxycycline &
hydroxychloroquine
Prevention
education
appropriate disposal
restrict access
pasteurized milk
laboratory clothing
vaccination
quarantine
holding facilities
routine testing
Chlamydia
• Page 379
Readings question #5:
What are the 3 species of Chlamydias that are
significant pathogens for humans? What is
the “elementary body” and “reticulate body”?
Chlamydias are transmitted to humans by
interpersonal contact or by airborne
respiratory routes.
Chlamydial pneumonia
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outbreaks among college students
transmitted by the respiratory route
50% U.S. population has antibodies
treatment: tetracycline
Chlamydia trachomatic
• Page 380
• Causative agent for:
trachoma
Lymphogranuloma veneruem
NGU (non-gonococcal
urethritis)
or
NSU (non-specific urethritis)
Trachoma
• Greek: “rough eye”
• arid parts of Africa and Asia, almost all
children are infected early in their lives
• 500 million active cases worldwide and 7
million blinded victims
• occurs occasionally in the southwestern U.S.
• transmitted by hand contact or by sharing
personal objects
Trachoma (cont’d)
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conjunctivitis leads to permanent scarring
long-term mechanical abrasion of the cornea
turned-in eyelashes
secondary infections
tetracycline ointment
partial immunity
sanitary practices and health education
Lymphogranuloma venereum
(LGV)
• Genital infections associated with an
increased risk of cervical cancer
• NGU/NSU: any inflammation of the urethra
that is not caused by Neisseria gonorrhoeae
– painful urination and watery discharge
– coinfection with C. trachomatis
Chlamycia psittaci
• Infected birds will usually have diarrhea,
ruffled feathers, respiratory illness, and a
generally “droopy appearance”
Prions
“small proteinaceous infectious agents
without a nucleic acid
genome……produce spongiform
encephalopathies”
Pathogenicity
• Page 384
• abnormally folded proteins that cause the
proteins to clump
• diseases have a long incubation time
• CNS damage is insidious
• no fever and inflammation
Readings Question #6
• Why are prions of a particular concern to
embalmers?
Creutzfeldt-Jakob Disease
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progressive disease
spongiform degeneration of the brain
rare: 200 cases/year in the U.S.
no treatment for CJD, always fatal
embalming implications discussed in FUN 247
and FUN 249