lab 15 and 16- gram negative bacilli/ family enterobacteriaceae and Urine culture

Opportunistic pathogen

Commensals may still cause disease in humans if they are introduced into another area within the body, for instance into the urogenital tract.

Enterobacteriaceae

-gram negative bacilli

-facultative anaerobes

-oxidase negative

-acid production from glucose

-most are catalase positive

-most reduce nitrate(NO3) to nitrite (NO2)

-peritrichous flagella if motile

eosin methylene blue agar (emb)

selective for gram negative bacteria

differential for lactose fermenters; appear purple or purple pink; ecoli appear metallic green

MacConkey Agar (MAC)

Selective for gram negative bacteria

differential for lactose fermenters; usually appear as pink colonies

What is the difference between a true pathogen and an opportunistic pathogen?

True pathogens (primary pathogens) cause disease in healthy individuals with intact immune systems, whereas opportunistic pathogens cause infection only when host defenses are compromised,

What tests are typically performed to characterize gram negative bacilli?

Gram staining, oxidase, indole, citrate utilization, urease activity, and lactose fermentation on MacConkey agar

UTIs urinary tract infections

Infections of the urethra and urinary bladders

cystitis

the inflammation of the urinary bladder

preparing urine sampls

Columbia CNA

10 ul disposable inoculating loops

35 C until the next lab meeting

Dysuria

initial symptoms (painful and frequent urination)

pyuria

presence of leukocytes and pus in urine

pyelonephritis

an inflammation of the kidneys either one or both kidneys.