MID 2 - Lecture 11 Flashcards
Diphtheria (toxin mediated disease)
Gram +, Rod, non spore, non motile, resistant to drying, respiratory
-Toxin mediated disease
AB toxin encoded by tox gene, inactivates elongation factor EF-2, blocks protein synthesis, cardic, kidney, nervous tissue destroyed
AB Exotoxin
secreted by Diphtheria (and others), two domains connected by disulfide bond, B binds to host cell (endocy), acidic environment of endosome breaks bond, releases A domain into cytoplasm, domain travels in body
Diphtheria (how presents in ppl)
> 30 yrs w/ weakened immunity, diagnosis = thick grey pseudomembrane in throat
-antibiotic therapy, immunization DTap vacc, antitoxin
Tetanus
anaerobic, gram +, endospores (soil, dust, hospitals, feces), through skin wounds, produces tetanospasmin (in low O2) = 2nd deadliest toxin, tetX encodes for AB toxin, blocks GABA release, muscle spasms
Tetanus (how presents in ppl)
tension/cramping (skeletal muscles, tight jaw), trismus (lockjaw), death = spasm of diaphragm and irm
-antibiotic therapy, DPT vaccine
Pertussis (whooping cough - PTx)
droplet inhalation, colonizes respiratory tract cilia, toxins have toxic affects
- PTx is an AB toxin
A subunit = ADP-ribosyl transferase, ADP ribose added to Adenylate cyclase, stuck in active state, ATP converted to cAMP (continous), secretion of thick mucous (death of cilia)
Pertussis (how presented in people)
7-14 day incubation, cold like symptoms, prolonged coughing sieges with inspiratory whoop, permanent immunity develops
-Bacterial culture, antibiotic therapy, DPT or Tdap acellular vaccine for older children/adults
Meningitis (diff types)
inflammation of brain or spinal cord meninges, headache, fever, stiff neck, many causes (viral)
- Pneumococcal (pneumonia, ear and sinus infections)
-Meningococcal (teenagers, young adults, dorms, boarding school)
- Haemophilus influenzae serotype B (not cause of influenza)
Meningitis (treatment)
s. penumoniae = vaccine, antibiotics
N. meningitidis = antibiotics, vaccine
H.influenzae = pneumonia and meningitis kill 3 mill worldwide/year, vaccine reduced to 1/100000
Tuberculosis
Caused by mycobacterium tuberculosis (Mtb), M. Bovis, M. africanum
-transmission: droplet nuclei in resp tract, infected animals and products, dormant infection reactivate
-develops slowly
mycobacteria produces mycolic acid in cell wall (protective)
resistant to penetration of some antibiotics, and dehydration
Infection of MtB (in person)
inhalation (10 cells enough), fever, fatigue, night sweats, weight loss, cough
-diagnosis
Observation of acid-fast bacteria, chest xray, mantoux, tuberculin skin test, DNA based tests
TB course of disease
lung macrophages phagocytosed to M tuberculosis often die in attempt to kill bacteria
-form granulomas
composed of bacteria macrophages, t cells, and human proteins, can become calcified, forms tubercles
Lyme disease
most common tick-borne disease in US, gram -, caused by borrelia burgdorferi, b.garinii, b.afzelii, spirochete
Lyme transmission by ticks
transmitted from animal reservoirs by ticks (deer, field mice, woodrats), complex, three stages (localized, disseminated, late stage)
Stages of lyme disease
localized: 7-10 days after infection, expanding, ring shaped, flu
disseeminated: weeks or months after infection, neuro abnormalities, heart inflammed, arthritis
Late stage: years later, demyelination of neurons, behavior, symptoms like alzheimers and MS
Lyme (diagnosis)
serological testing, isolation of spirochete from patient, detection of borrelia DNA (PCR)
treatment: antibiotic therapy early, tick control, education/ personal protection
Gastroenteritis
inflammation of stomach and intestinal lining
Food poisioning
food is source of pathogen
Food borne infection
pathogen must colonize host
food intoxication
ingestion of toxin (enterotoxins - disrupts intestinal mucosa causing nausea, vomiting, diarrhea)
Peptic Ulcer disease
gram -, caused by helicobacter pylori
Colonizes gastric mucus-secreting cells, produces urease (increase pH), releases toxins that damage epithelisal mucosal cells), 50 % affected
H. pylori disease
colonzies gastric mucus secreting cells, beneath gastric mucosa by aid of surface fimbriae, produces ureases, hydrolyze ammonia and provides local alkaline environment
H.pylori disease (diagnosis)
culture biopsy speciments, examine stained biopsies, serological testing, urea breath test, tests for ammonia in urine, detection of urease activity in biopsies
treatment: combination of drugs to decrease stomach acid and antibiotics to kill bacteria
Cholera
ingesting food or water contaminated by fecal matter from carriers, adheres to intestinal mucosa of small intestine and secrete toxin choleragen (AB toxin), presence of toxin results in major loss of water and electrolytes
cholera (diagnosis)
culture from species with subsequent identification by agglutintion rxns
treatment: oral rehydration, antibiotic therapy, sanitation of water supply
Salmonellosis
gram -, non spore forming rods, in intestinal tracts, contaminated foods (beef, poultry, egg products, water)
abdominal pain, cramps, diarrhea, nausea, vomiting, fever
treatment: fluid, electrolytes, food handled carefully
Typhoid fever
salmonella enterica subspecies, gram - rod, AB toxin, food or water by feces, infection from small intest to lymphoid tissue, blood, liver, gallbladder
Fever, headache, abdominal pain, anorexia, malaise
-in carriers bacteria grow in gallbladder, reach intestine through bile duct
Typhoid (diagnosis)
demonstration of typhoid bacilli in blood, urine, or stools, serology
treatment: antibiotics, vaccine, food handling, purification of water, isolate patients
Dental disease
various odontopathogens, hard enamel, neg charged surface repel bacteria, formation of dental plaque = pathogens producing acids
Dental plaque
acquired enamel pellicle
colonized by various bacterial species to form, streptococcus mutans attach produce polysaccharide cement from sucrose,
lactic acid production: demineralize enamel, breached enamel = bacterial entry
Dental decay
demineralization/remineralization cycle
production of acids leads to release of calcium and phosphate ions from enamel followed by remineralization
Demin > remin = caries
treatment: no drugs, good dental hygiene, minimize ingestion of sucrose
