LECOM Microbiology Lecture 7 Urinary Tract Infections

What are the characteristics of Escherichia coli

o Gram negative rod

o #1 cause of UTIs

o Endogenous- due to gut flora

o Can establish infection in urethra, bladder, and kidneys

what is the virulence factor for UPEC

§ Pili- adheres to urinary tract

· Type 1 pili-

o Interacts with the bladder

o E. coli attaches to where urine flows through

· P pili

o Interacts with kidneys.

what are the lab characteristics of E. coli

§ Growth on MacConkey agars- lactose fermenter (positive)

· Also, Hektoen-Enteric agar- lactose fermenter, salmon pink color

§ Indole positive

· Converts tryptophan to indole

What bacteria strains cause Coagulase Negative Staphylococci (CoNS) UTIs

o Staphylococcus saprophyticus

§ Normal flora

§ Seen in young sexually active females

§ Novobiocin resistant

o Staphylococcus epidermidis

§ Normal flora

§ Associated with catheters, nosocomial

§ Novobiocin sensitive

what are the lab characteristics of Coagulase Negative Staphylococci (CoNS) UTIs

§ Gram positive grape-like clusters (Appears purple)

§ Catalase positive

§ Coagulase negative

§ Novobiocin sensitivity

· S. saprophyticus is resistant

· S. epidermidis is sensitive

S. saprophyticus is novobiocin (sensitive or resistant)?

resistant

S. epidermidis is novobiocin (sensitive or resistant)?

sensitive

what are the lab characteristics of proteus mirabilis (proteus vulgaris)

§ Gram negative rod

§ MacConkey agar test: Lactose non-fermenter, negative

§ Urease positive

§ Swarming motility

what is the virulence factor of proteus mirabilis

urease

what conditions is caused by proteus mirabilis

kidney stone - Due to urease increasing urine pH (converts urea to ammonia and CO2)

formation and UTIs

what does Schistosoma haematobium cause and where is it geographically located

"Swimmer's Itch"

-Africa and Middle East

Characteristics of Schistosoma haematobium

o S. haematobium: t for egg, t for terminal spike

§ Detected in urine

what can only schistosoma species cause?

§ Urethritis, cystitis

§ Squamous cell carcinoma of the bladder

· Most common cause of bladder cancer in Africa

§ Cause of UTI symptoms?

· Eggs have spikes that attach to bladder repeatedly, causing infection