Microbio Infections 2

called otitis media
infants eustachian tube is at a lower angle (10 degrees)
common pathogens: streptococcus pneumoniae and haemophilus influenzae

most common infectious disease
lytic but typically cause mild disease
common pathogens: rhinoviruses, coronaviruses, adenoviruses

inflammation of larynx, barking cough, typically self-limiting
common pathogens: parainfluenza virus

also known as Group A Strep (GAS), many strains
often produce exotoxins (e.g. hemolysins)
prompt antibiotic treatment important

A. pharyngitis (strep throat)
-pus in lymph tissue, fever, very contagous
B. scarlet fever (exotoxin)
-causes fever and red rash, now less virulent in US

autoimmune complication of S. pyogenes infection
can result in heart and kidney damage, inflammation of joints
result of molecular mimicry

gram (-) with capsule
droplet transmission, attatches to ciliated epithelial cells in trachea, toxins lyse cells
inflammation, mucous, blocked airways, violent coughing, cyanosis result
DTaP acellular vaccine
common pathogens; bordella pertussis

site of gas exchange (O2 and CO2)

Bacterial pneumonia

top bacterial killer worldwide
waxy cell prevents desiccation as well as efficient phagocyte killing
long generation time (~18 hours)
common pathogens: mycobacterium tuberculosis

lower respiratory infection
mild in most, some infants suffer
vaccine available

viral: viral encephalitis, poliomyelitis
bacteria: bacterial meningitis, meningococcal meningitis, listeriosis
bacterial neuotoxins: botulism, tatanus

acute sudden headache, neckache, fever, confusion, CNS inflammation/damage
often fatal

primarily in teens/20s
pharynx colonized, invades blood, crosses blood brain barrier, infects meninges
vaccine exists
common pathogens; neisseria meningitidis

A. streptococcus pneumoniae (infants and older adults)
B. haemophilus influenzae (Hib vaccine used in infants)
C. listeria monocytogenes (foodborne, crosses placenta, infants and older adults)

gram (+) strict anaerobe, endospores from soil germinate in deep wounds
tetanospasmin exotoxin (neurotoxin) causes rigid peralysis
anti-toxin antibody can neutralize toxin (passive immunity)
toxoid vaccine (DTaP) provides active immunity
common pathogens: clostridium tetani

endospores in soil
neurotoxin inhibits muscle contraction, causes flaccid paralysis, potential respiratory failure
prevents acetylcholine neurotransmitter release from motor neurons
treat with anti-toxin
common pathogens: clostridium botulinum

foodborne intoxication
infant: endospores consumed (e.g. in soil, honey)
wound: spores germinate in necrotic tissue

transmitted via mammal bite, virus in neurons, saliva
slowly invades CNS, sevre neurological damage
~100% mortailty w/o post-exposure immunization

cause brain inflammation
mosquito vector common, often bird reservior
west nile, eastern and western equine encephalitis viruses

nearly eradicated
fecal-oral transmission

gram (-) diplococcus, highly infectious
virulence factors: attatchment pili, IgA protease, endotoxin, invades phagocytes
disseminated infections can cause serious infections in other organs/tissues
must treat partner, no vaccine, increasingly antibiotic resistant
common pathogens: neisseria gonorrhoeae

males: urethritis with pus within 1 week
females: more insidious, 80% asymptomatic, chronic inflammation can cause PID, sterility

main cause of nongonococcal urethritis (NGU), a non-neisseria urethritis transmitted as STI
most common bacterial STI, more often diagnosed in females
most infections (80%) are asymptomatic or mild symptoms
major cause of PID and infertility
can cause infections in newborns
common pathogens: chlamydia trachomatis (obligate intracellular)

hihgly evasive, establishes latent infections, weak secondary immunity
no vaccine but antibiotics are effective
common pathogens: treponema pallidum (spirochete)

1. incubation period (weeks)
2. primary stage: hard chancre (sore) at infection site, heals (latent stage follows, weeks to years)
3. secondary stage: rashes, skin/mucous membrane lesions, which later heal (latent stage follows)
4. Tertiary stage: gummas (granulomas) form in tissues (severly damage CNS, heart, other organs)

mental and physical abnormalities

latency in neuron
HSV-1: oral infections
HSV-2: genital infections
neonatal herpes can be lethal

latent herpesvirus
can cause disseminated infection in newborns and immunocomprimised individuals

causes genital warts and cervical cancer
vaccine available