3/9/99

Microbiology II

 

Listeriosis

·        Caused by Listeria monocytogenes

·        Gram positive, small, rod

·        Common in improperly processed milk, cheese, meat, vegetables (most common)

·        Can be carried by pets and transmitted to humans

·        Low temps (4-10°C) of refrigeration not enough to kill organism

·        Know to survive in frozen foods (-20°C)

·        Can be deadly in immunosuppressed patients causing bacteremia®septicemia®meningitis®kidney damage®can cross placenta causing abortion, still birth, neonatal death

·        Tx:  chloramphinicol (life threatening situation only), 1^st generation cephalosporins

 

Enterobacteriaceae

Proteus	Serratia
Gram negative, rod w/flagella	Human pathogen
All over peritrichous	Gram negative, rod, non-motile
Positive for phenylalanine deaminase (breakdown of phenylalanine into NH4OH	Forms purple, red, or pink colonies at 37°C
Most species known for urinary tract infections—smell of ammonia prominent	Serious in immunosuppressed patients
4 species 1.  Proteus mirabilis—most frequent cause of urinary tract infections 2.      P.  rettgerii 3.      P. morganii 4.      P. vulgaris—WEIL FELIX test; used in Dx of rickettsial disease	Several species 1.      S.  marcescesn—nosocmially transmitted—bacteremia, septicemia, pneumonia, woiund infections, etc.
Ascending Pyelonephritis—may be result of UTI	Shows multiple drug resistance
May also result in kidney stones by initiation of struvite	Tx:  3rd generation cephalosporins
NH4OH (ammonium hydroxide) causes high urine pH damaging the nephron—corrosive	Organism used in killed form as organism to receed benign tumors
May cause pneumonia	Phagocytose tumor cells (non-specific immunity)
Tx:  change in pH of urine back to acidic—Vit C, carbamicillin, 3rd generation cephalosporins	others®BCG+ for TB, vaccinia virus, cornybacterium

 

Francisella tularensis

·        Tuarmia is the result

·        From game animals—skinning, handling meat, inhalation of droplet

·        Zoonosis—organism transmitted to humans via animal

·        7 different forms

·        clinical manifestations—abrupt onset of fever, chills, malaise; lasts weeks (104-105°C)

1. ulcero—glandular—ulcers form—most common on fingers
2. oculo-grandular—eyes involved
3.  typhoidal (104-106°C)—blood involved—common septicemia (buboes)
4. orophryngeal—sore throat
5. GI
6. Meningitis
7. Pneumonitis/pulmonary—inhalation

 

#1 can result in #3 which can lead to #6