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Spirochetes Curved Gram Negative Rods
Treponema pallidum
Syphillis
- Yaws(tropical worldwide), Pinta(American), Bejel(Africa, Asia, Australia)
- RPR aka VDRL in blood
- Gummas
- Painless chancre @ initial site of infection
- MHA-TP dx
- Secondary stage rash on palms and soles
- DOC PCN
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Spirochetes Curved Gram Negative Rods
Borrelia burgdorferi
Lyme Disease most common in US
- Other species cause Relapsing Fever in U.S. and worldwide
- Transmitted by louse or tick, deer tick in CT
- erythema migrans 60 to 80% of patients infected have this mark.
- Arthritis
- DOC DOXY
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Spirochetes Curved Gram Negative Rods
Leptospira
Weil's Disease( fatal kidney and liver failure)
- Broken skin is exposed to animal urine rat urine or contaminated water or soil or by ingestion
- tightly coiled spirochetes with hooked ends L. interrogans
- worldwide living in soil and freshwater
- 30 degrees C liquid media in dark
- urine looking for leptospires using darkfield scope
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Vibrio Curved or S shaped Gram Negative Rod
Resistant to salt
Ingestion of contaminated water
Shellfish most common in US
- Vibrio Vulnificus
- cause most seafood-related death in US
- death by seafood
- Vibrio Cholerae
- rice-water
- fluid loss by vomiting
- NO FEVER
- TX electrolye replacement therapy
- Adenylate cyclase toxin
- Vibrio parahemolyticus
- most common cause of diarrhea in Japan
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Campylobacter Curved or S shaped Gram Negative Rod
Probably most common cause of bacterial gastroenteritis in US today
Spread from contact with infected animal or food
Undercooked poultry
- Campylobacter Enteritis
- highest incidence in infants and young children followed by adults 20-40
- dx: isolate from stool
- blood-based campy media
- 10% CO2 42 degree C reduced O2
- Campylobacter jejuni
- most common cause of diarrhea in the US
- Guillain-Barre' Syndrome
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Helicobacter Curved or S shaped Gram Negative Rod
Helicobacter pylori
Cause stomach ulcers
- Acute gatritis
- Sx: abdominal pain nausea vomitting
- becomes chronic
- causes 60% of all cases of stomach cancer even if no ulcer present
- migraines when ulcer is treated migraine go away
- DX: Gastric biopsy, rapid urease test, urea breath test
- TX: multi-drug regimen
- metronidazole or clarithromycin given with anti-acid medications
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Mycoplasma
smallest free-living organisms
no cell wall
no gram stain
tiny colony looks like fried egg
- common in most mammals
- humans associated with mucus membranes
- cause human disease in URT and urogenital tract
- DX: antigen detection PCR or DNA probes
- TX: tetracycline or macrolides erythromycin
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Mycoplasma pneumoniae
Tri-layered cell membrane
pleomorphic
- Causes 20% of community-acquired pneumonia
- walking pneumonia
- last for wks and can infect entire household
- usually not cultured out, since it may take 2-6wks
- infectious even while on antibiotic
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Mycoplasma and Ureaplasma
Cause urogenital infections
- Nongonococcal urethritis NGU
- can become PID or kidney infections
- some species are STDs, although urinary and genital tracts of babies and young girls can also be colonized
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Rickettsia Gram Negative small obligately intracellular bacteria
Transmitted ticks, lice, mites, etc
Worldwide distribution causes tick-typhus
- Rocky Mountain spotted fever
- most common rickettisial disease in US
- seen in Southeastern US and Appalachia
- tick bite
- rash is very distinctive on palms and soles
- petechial in half cases
- death can result from kidney respiratory or heart failure
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Rickettsia Gram Negative
Epidemic or Louse-Borne Typhus
Body Louse
- common in crowded areas
- infected louse defecates while feeding person scratches bite, rubs feces into the wound
- more common in colder area reservoir in US
- SX: fever, headache, malaise rash palms and soles does not extend to face
- disease can reappear yrs later at Brill-Zinsser
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Rickettsia Gram Negative
Ehrlichia
Obligate intracellular parasite of WBC leading to leukopenia
- HGE: Human Granulocytic Ehrlichiosis is found in northern states Dx: nuetrophil is best cell to dxing
- HME: Human Monocytic Ehrlichiosis found in southern states DX: monocyte cell is best cell to dxing
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Chlamydia Nonmotile Gram Negative Obligate Intracellular Bacteria
Chlamydia trachomatis
DX: tissue cultures, genital swab or urine culture, sputum, throat swab, conjunctival swab
- causes trachoma of the eye and genital disease, pneumonia in infants, cervical cancer
- non-gonococcal urethritis in men
- most common bacterial STD in US
- SX: can be mild to none females: can develop PID resulting in sterility or ectopic pregnancy
- can cause eye infection n babies passing through birth canal of infected mother, or conjunctivitis in adults
- TX: tetracyclines, macrolides(erythromycin) rifampin
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What 3 diseases must you consider after a tick bite in New England area especially in CT
Lyme disease(Borrelia bergdorferi, a spirochete bacteria)
Ehrlichiosis or HGE/HME(Ehrlichia, an obligate intracellular bacteria)
Babesiosis (Babesia microti, a protozoan)
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Chlamydia pneumomiae Nonmotile Gram Negative obligate intracellular bacteria
- can cause pharyngitis, bronchitis, or mild pneumonia from contact with respiratory droplets
- may be responsible for 10% of community-acquired pneumonias
- atherosclerosis
- arthritis
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Chlamydia psittici Nonmotile Gram Negative obligate intracellular bacteria
- parrot fever or ornithosis
- causes psittacosis, infected birds and mammals or breathing in aerosolized bird droppings
- SX: fever, headache, chills, leading to pneumonia
- causes abortion in domestic mammals or in pregnant women who are exposed to infected animals
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Nesisseria Gram Negative Cocci
Only genus that causes disease in humans
coffee bean-shaped always in pairs
- dislike cold and temps
- needs enhanced CO2 atomosphere
- fimbria
- capsules
- Lipooligosaccharide (LOS) a combination of Lipid A and sugar
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Nesisseria gonorrhoeae Gram Negative Cocci
coffee bean shaped always in pairs
- gonorrhea one of the common STDs
- attaches to mucosal cells using fimbriae
- can infect mouth, anus, cervix, vagina, urethra, eye
- SX: Male painful urination, discharge of pus from urethra, gram stain of penile exudate is diagnostic Female:infect cervical cells, mild urethritis or increased vaginal discharge
- left untreated can cause PID
- opthalmia neonatorum
- penicillinase not beta-lactamase
- thayer martin agar or nyc agar
- DOC ceftriaxone or cefixime given as a single dose
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Nesisseria meningitidis Gram Negative Cocci
coffee bean shaped always in pairs
Meningitis
- LOS Lipooligosaccharide
- person to person through direct contact with respiratory secretions
- outbreaks in high-density areas college dorms, military camps where young ppl are crowded into stressful environment
- UCONN at Storrs
- Vaccine available
- Petechia rash or purpuric skin rash in 75% of cases
- TX: PCN, chloramphenicol, or broad spectrum cephalosporins
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Pasteurella Gram Negative Rod
Small nonmotile
Fastidious requires heme
- Pasteurella multocida: seen after cat bite
- SX: inflammation at site of bite can spread to systemic infection
- TX: PCN, tetracycline, or cephlasporins
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Haemophilus Small Gram Negative Rod Plemorphic
Requires Heme X(X factor) V(NAD) for growth
obligate parasites
colonize mucous membranes of humans and animals
- Haemophilus influenzae Pink eye, ear infections,
- bacterial meningitis and epiglottitis in children under age 5
- must be grown on chocolate agar under 5% CO2
- transmitted by exposure to nasal exudate or aerosolized droplets
- will grow on blood agar if S. aureus is present
- TX: rifampin
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Haemophilus aegyptius
Small plemorphic Gram Negative Rods
Brazilian purpuric fever in children which begins with conjunctivitis which can progress and become fatal rapidly
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Haemophilus ducreyi Gram Negative Rods
Small pleomorphic
- Chancroid or soft chancre: causes sexually transmitted disease
- produces ulcer at the site of infection most visible on the penis caused a toxin that kills human epithelial cells
- common in tropical areas but rare in US
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Bartonella Gram Negative Aerobic Bacilli
- Bartonellosis: bite of sand fly in South America
- SX: anemia, headaches, skin infections,
- Trench Fever: body lice common in WWWI
- SX: recurrent fever
- Cat-Scratch Disease: from cat bite or scratch or cat flea bite
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Brucella Gram Negative Aerobic Bacilli
small aerobic nonmotile coccobacilli
- can pass thru minute cuts on skin
- contracted from infected animals or animal products,
- Undulant fever: chills, headache, muscle aches, wt loss,
- TX: antibiotics for 6wks
- Biosafety Level III pathogen
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Pseudomonas aeruginosa Gram Negative
Small coccobacilli not fastidious grows well on MacConkey
- not normal flora should be treated if on body Cystic fibrosis: patients that usually get breathing treatments
- Swimmers ear: eye infections that can quickly result in blindness
- Pyocyanin: a blue-green pigment, triggers formation of oxygen radicals which can damage tissue
- Cystic Fibrosis Lung Infection
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Bordetella Gram Negative Aerobic Bacilli
Small aerobic, nonmotile coccobacillus
- Bordetella pertussis: human pathogen causing Whooping Cough
- Adenylate cyclase toxin which causes mucous excretion cells to go into overdrive
- vaccine available
- DX: cultured on media that's very rich in blood preferably 20% horse blood
- Cough plates held under patients mouth o
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Francisella tularensis Gram Negative Aerobic coccobacillus
- Biosafety III
- Rabbit Fever: causes tularemia usually acquired from exposure to infected animals esp rabbits.
- aerosolized and breathed in, can also be swallowed in water or food injected by bite of insect from skin mucous
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Leginonella pneumophila Aerobic Gram Negative pleomorphic Rod
- present in all types of water even chlorinated
- must be aerosolized by a fountain or water tower and breathed in to cause infection
- SX: flu like, progresses to high fever, respiratory failure and death
- Pontiac Fever: in younger ppl Pontiac Michigan where an entire health dept was infected
- DOC is erythromycin rifampin
- Legionnaires Disease:
- BCYE: Buffered Charcoal Yeast Extract, since yeast is rich in both of the above factors
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Coxiella burnetti Small Aerobic obligate intracellular parasite
transmitted by tick bites
- transmitted to humans by dust or dander from infected animals or ticks
- Q fever: usually in animals handlers, acute Q fever is like the flu, chronic may take years to cause endocarditis
- most common cause of endocarditis in Australia
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Anaerobic Gram Negative Rods
Bacteroides fragilis
- Bile Resistant
- accounts for 85% of GI diseases such as peritonitis, genital infections, and wound infections
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Anaerobic Gram Negative Rods
Prevotella
- Bile Sensitive
- is seen in sinus, ear, periodontal infections and in pelvic infections.
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Gram Negative nonsporeformers either aerobic or facultative
Escherichia coli
true stool pathogen
- causes most UTIs than any other organism
- accounts for most traveler's diarrhea some strains may have toxins similar to Shigella
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E coli O157:H7
1980's (Sorbitol)
non-lactose fermenters
- sorbitol negative
- hemolytic uremic syndrome in children-elderly leading cause of kidney failure in children in US
- consumed in contaminated meat with animal feces that is insufficiently cooked increasingly seen in vegetables and fruits grown around animals
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Salmonellosis Gram Negative nonsporeformers
aerobic or facultative
fermenter of glucose
- common Isource poultry especially eggs never eat raw eggs Transovarian transmission
- chicken transmits bacteria into the eggs before they laid them
- Invade intestinal mucosa and multiply there
- SX: fever, cramps, diarrhea, nausea
- can invade blood stream especially in young and old
- TX: self-limiting no antibiotics
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Salmonella typhi
- Typhoid fever: uniquely to humans not seen in animals
- SX: high fever headache diarrhea in 2nd-3rd week
- bacteria multiply in phagocytic cells
- rare in US but seen worldwide when sanitation is poor
- Vaccine for typhoid fever
- Typhoid Mary
- TX: 3rd generation of cephalosporins like ceftriaxone
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Shigella
- 4 species which cause bacillary dysentery aka Shigellosis
- severe diarrhea with abdominal cramping and fever
- produce a toxin shiga toxin which inhibits protein synthesis killing infecting cells
- TX: fluoroquinolone like ciprofloxacin oral rehydration
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Yersinia pestis
transmission occurs from fleas
- Now confined to a few endemic areas Africa America and Asia most common in US in Southwest
- after bitten by flea organism travels to bloodstream to nearest lymph node
- SX: bubo intense inflammatory response causing swelling of lymph node, septicemic followed by meningitis or pneumonia
- pneumonic plague can then be spread person to person via aerosol
- Black death due to necrotic lesions in peripheral blood vessels
- TX: vaccines- neither vaccine is very effective against pneumonic disease streptomycin is DOC but tetracycline gentamycin or chloramphenicol also effective
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Yersinia enterocolitica Yersinia pseudotuberculosis
- Causes gastroenteritis or yersiniosis
- Bloody diarrhea, fever, headache, and abdominal pain so severe it may be misdiagnosed as appendicitis
- usually associated with ingesting raw pork or pork products
- bacteria can multiply at refrigrator temps
- occasionally transfused blood
- causing infection and shock to blood recipient
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