<Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> Pyelonephritis is inflammation of the kidney, typically due to a bacterial infection . Symptoms most often include fever and flank tenderness . Other symptoms may include nausea, burning with urination, and frequent urination . Complications may include pus around the kidney, sepsis, or kidney failure . </P> <P> It is typically due to a bacterial infection, most commonly Escherichia coli . Risk factors include sexual intercourse, prior urinary tract infections, diabetes, structural problems of the urinary tract, and spermicide use . The mechanism of infection is usually spread up the urinary tract . Less often infection occurs through the bloodstream . Diagnosis is typically based on symptoms and supported by urinalysis . If there is no improvement with treatment, medical imaging may be recommended . </P> <P> Pyelonephritis may be preventable by urination after sex and drinking sufficient fluids . Once present it is generally treatment with antibiotic, such as ciprofloxacin or ceftriaxone . Those with severe disease may required treatment in hospital . In those with certain structural problems of the urinary tract or kidney stones, surgery may be required . </P>

Pyelonephritis is usually caused by which type of organism