Streptococcus Pneumoniae, Listeria, C. Perfringens

Gram (+) Pt 2

Positive, alpha, asymptomatic, capsule

Streptococcus Pneumonia

• Gram (+), catalase __, __ hemolytic

• 5-40% of healthy individuals are __

• Route of infection is respiratory transmission, community-acquired

• Virulence factors - Exotoxin, __ (MOST IMPORTANT VF)

Pneumolysin, alpha, endothelial, cilia, immuno

• __ is an exotoxin that degrades some of hemoglobin (__)

  • Toxic to pulmonary __ cells, affects __, __suppression

(strep pneu.)

Pneumonia, bacteremia, meningitis, otitis media, sinusitis

Clinical manifestations of strep pneu.

• __, __emia , __ingitis, __ media (pediatric), __itis

Pneumonia, pleuritic

__ sx - Fever, chills, chest pain, SOB, cough, __ pain

(strep pneu.)

antibody, antigenic

Immunity of pneumonia by __ to capsule antigens

• Vaccines exist but do NOT offer complete protection, due to __ variation

Conjugate polysaccharide

Subunit (__ __) vaccine prevents Strep pneumonia infection

Short, positive, beta, motile, facultative, intracellular

Listeria Monocytogenes

• Rod shape, __ (long/short) bacilli, catalase __, __-hemolytic

  • __ - Tumbling motility by light microscopy, with several flagella

• Found everywhere in environment, __ pathogen; primarily foodborne

• __ pathogen growing inside eukaryotic cells

Internalin A, Listeriolysin O

Virulence factors of Listeria

• ___: Surface proteins involved in listeria invasion

• __ __: (LLO): Pore-forming exotoxin activated from acidic pH of phagolysosome to destroy phagolysosome

Attach, E, zipper

Internalin A from Listeria

• __ to epithelial _-cadherin receptors

• “__” mechanism to trigger phagocytosis and cell entry

Phagolysosome, macrophages

Listeriolysin O from Listeria

• Escape the __

• Allows survival and replication in __

Soil, feces, proteolytic, stomach, bile, pregnant, motility

• Listeria primary sources - __ and water, animal intestines, __, raw foods, decaying matter

• Listeria able to survive exposure to __ enzymes, __ acid, and __ salts

• Those at risk - __ women, neonates, elderly

• Dx is from a __ test by culture

Actin, extracellular, antibodies, macrophages

Cellular pathology of Listeria

• Assembly of __ fibers allow Listeria to move thru cell and direct into adjacent cell

• Spread cell to cell without exposure to __ environment → immune evasion of __

• Infection of __ in intestinal lining leads to bacteremia

Listeriosis

Most cases associated with un-pasteurized dairy products, poultry, and undercooked meat

Intestinal, 1, 2, diarrhea, nausea

• Listeriosis - Mild or subclinical __ illness in healthy adults

  • Acute self-limited gastroenteritis; _ day incubation and _ days of infection

  • Sx - __, __, fever, headache

Sepsis, meningitis

High risk patients with listeriosis can have invasive disease - (2)

3rd, intra, utero, perinatal

• Listeriosis in fetus and neonates can be acquired transplacental (during __ trimester or __partum)

  • __ Infection Complications - Stillbirth, miscarriage, premature birth

  • __ Infection Complications: Meningitis with septicemia

soft cheeses, processed meats, unpasteurized

Prevention of listeriosis in pregnant women by diet =

Avoid __ __ (dairy), __ __ (protein), meat spread, __ milk (dairy)

Obligate, spore, heat, desiccation, disinfectants, exo

Clostridium Perfringens

• Large bacilli, __ anaerobe, __-forming

• __ resistant to __/__/__

• Can produce numerous __toxins

• Found everywhere in environment

Alpha, lipids, lyse, toxemia

• C perf produces a different __ toxin → Breaks down __ in cell membranes and __cells

  • Key component of __ in wound infection (gas gangrene), hemolytic

Myonecrosis, 1-3

__ is Soft tissue death and wound infections (term for gas gangrene)

• Contaminated wound can progress in _-_ days

Gas gangrene sx

Sudden onset of severe pain at site of trauma, foul smell, fever

Gas gangrene predisposing

__ __ __ factors - surgical incisions, compound fx, diabetic ulcers, septic abortions, puncture wounds, GSWs, trauma-mediated

Tachy, fever, shock, organ

Gas Gangrene systemic sx - __cardia,__, __, multi-__ failure

Not, anaerobic, spore, exo

C perf pathology

• __ (is/not) highly invasive, requires damaged and dead tissue with __ conditions

• Conditions stimulate __ generation, release of __toxins

Crepitation, CO2

__ is fermentation of muscle carbohydrates results in __ (gas) formation and further tissue destruction

Hyaluronidase, collagenase, proteinases, exotoxin

C perf - gangrene gas

• Extensive local tissue destruction → Produce __, __, __ (3 -ase enzymes)

• __ effects can progress to shock and death

Debridement, amputation, hyperbaric

Treatment of Gas Gangrene

• __ of dirty/deep wounds, compound fx, infected incisions

• Possible __ of affected limb

• __ oxygen therapy

Entero, spore, extra, small intestinal

Clostridial food poisoning

• Relatively mild intestinal illness from __toxin

• Bacteria accumulates at start of __ formation from undercooked food, excreted into __cellular environment

• Once in stomach, C. perf binds to __ __ epithelium

Ion, entero, heat

Clostridial food poisoning

• Disrupts __ transport and membrane permeability

  • C perf __toxin (exo/endo) is then produced by bacteria in gut

• This enterotoxin is __ labile (destroyed w/ heat)

Clostridial food poisoning sx

__ __ __ __ - Acute abdominal cramps, diarrhea, nausea

• NO vomiting OR fever

6-24, 24

C perf poisoning onset - Generally _-_ hours after eating food, less than __ hour duration

140, 40

Prevention of Clostridial food poisoning - Keep food hot at __ F or less than __ F