course hero what pathogen accounts for the majority of pyelonephritis

What is the pathophysiology of acute pyelonephritis?

PATHOGENS Like uncomplicated cystitis, the vast majority of acute uncomplicated pyelonephritis (AUP) is caused by E. coli (75-95%). Additional pathogens include other Enterobacteriaceae (e.g., Klebsiellaspp.) and S. saprophyticus.

Which pathogens cause pyelonephritis (kidney infection)?

Additional pathogens include other Enterobacteriaceae (e.g., Klebsiella spp.) and S. saprophyticus. Proteus spp. can cause pyelonephritis; repeated episodes with this pathogen should raise concern for struvite stones.

What causes uncomplicated pyelonephritis (AUP)?

Like uncomplicated cystitis, the vast majority of acute uncomplicated pyelonephritis (AUP) is caused by E. coli (75-95%). Additional pathogens include other Enterobacteriaceae (e.g., Klebsiella spp.) and S. saprophyticus. Proteus spp. can cause pyelonephritis; repeated episodes with this pathogen should raise concern for struvite stones.

What is the pathophysiology of Escherichia coli (E coli) pyelonephritis?

Route of infection is ascending: organisms enter urethra, colonize bladder, ascend to the renal pelvis and ultimately invade renal parenchyma. More virulent forms of E. coli are more likely to cause uncomplicated acute pyelonephritis than cystitis but are more susceptible to antimicrobial therapy.

What is the most common pathogen associated with pyelonephritis?

Escherichia coli is the most common pathogen in acute pyelonephritis, and in the past decade, there has been an increasing rate of E. coli resistance to extended-spectrum beta-lactam antibiotics.

What are the causes of pyelonephritis?

What are the causes of kidney infections (pyelonephritis)?Structural abnormalities (strictures, stents, stones, surgery) blocking urine flow.An enlarged prostate gland (benign prostatic hyperplasia) compressing the urethra.Backflow (reflux) of urine from the bladder to the kidneys.More items...•

What is the most common mechanism in pathogenesis of chronic pyelonephritis?

Reflux of infected urine into the renal pelvis is the usual mechanism.

What types of bacteria are the most common to cause urinary tract infections?

The most common bacterium to cause UTIs is Escherichia coli (E. coli). It is usually spread to the urethra from the anus. Other micro-organisms, such as mycoplasma and chlamydia, can cause urethritis in both men and women.

What type of bacteria causes pyelonephritis?

The main cause of acute pyelonephritis is gram-negative bacteria, the most common being Escherichia coli. Other gram-negative bacteria which cause acute pyelonephritis include Proteus, Klebsiella, and Enterobacter. In most patients, the infecting organism will come from their fecal flora.

What bacteria causes acute pyelonephritis?

MICROBIOLOGY. In 80 percent of acute pyelonephritis cases, Escherichia coli is the responsible pathogen in women, although it is not as common in older persons. After E. coli, less common causative organisms include other Enterobacteriaceae, Pseudomonas aeruginosa, group B streptococci, and enterococci.

What is the pathophysiology of chronic pyelonephritis?

Etiology and Pathophysiology Chronic pyelonephritis is associated with progressive renal scarring, which can lead to end-stage renal disease (ESRD). For example, in reflux nephropathy, intrarenal reflux of infected urine is suggested to induce renal injury, which heals with scar formation.

How does chronic pyelonephritis occur?

Each ureter has a one-way valve where it enters the bladder, preventing urine from flowing back up the ureter. Reflux occurs when these valves fail, allowing backflow of urine into the kidney. If the bladder is infected or the urine contains bacteria, the kidney then becomes infected (pyelonephritis).

How common is acute pyelonephritis?

There are approximately 250,000 cases of acute pyelonephritis each year, resulting in more than 100,000 hospitalizations. The most common etiologic cause is infection with Escherichia coli.

What is pathogen of UTI?

Urinary tract infections (UTIs) are a severe public health problem and are caused by a range of pathogens, but most commonly by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis and Staphylococcus saprophyticus.

Why is E. coli the most common cause of UTI?

Women are particularly at risk for UTIs because their urethra sits close to the anus, where E. coli is present. It's also shorter than a man's, giving the bacteria easier access to the bladder, where the majority of UTIs occur, and the rest of the urinary tract.

What are pathogens in urine?

The etiology is varied, but in approximately 90% of cases, enteric bacteria are implicated, especially Escherichia coli, which produces >70% of these infections. Other urinary tract pathogens are Klebsiella spp., Enterobacter spp., Proteus spp., Pseudomonas spp., Enterococcus spp., and Staphylococcus saprophyticus (2).

Which pathogens are more likely to cause acute pyelonephritis than cystitis

More virulent forms of E. coli are more likely to cause uncomplicated acute pyelonephritis than cystitis but are more susceptible to antimicrobial therapy.

When diagnosis suspected, always obtain urine (via clean-catch, mid-stream sample OR catheterized specimen) for

When diagnosis suspected, always obtain urine (via clean-catch, mid-stream sample OR catheterized specimen) for urinalysis and culture (with antibiotic susceptibility testing).#N#Urine specimen: should be received in the laboratory within 1 h of collection (or stored at 4°C and tested within 18h) to reduce risk of overgrowth of bacteria.#N#Bacterial colony counts typically >100,000 CFU/mL.#N#Absence of pyuria and bacteriuria suggest an alternative diagnosis (unless obstruction present).

What are the symptoms of UTI?

Clinical: signs and symptoms include fever, chills, flank pain, nausea, and vomiting. Patients may or may not have symptoms of a lower tract UTI ( uncomplicated acute bacterial cystitis ). Abdominal and/or pelvic pain may be present. Costovertebral angle tenderness to percussion typical.

What pathogens cause struvite stones?

Additional pathogens include other Enterobacteriaceae (e.g., Klebsiella spp.) and S. saprophyticus. Proteus spp. can cause pyelonephritis; repeated episodes with this pathogen should raise concern for struvite stones. S. agalactiae and Enterococcus spp. are possible but uncommon pathogens.

Is S. aureus a pathogen?

S. agalactiae and Enterococcus spp. are possible but uncommon pathogens. S. aureus is an uncommon pathogen and should raise concern for other infectious process (e.g., blood stream infection, endocarditis).

Is ceftolazone tazobactam better than levofloxacin?

Ceftolazone-tazobactam was non-inferior to levofloxacin in achieving clinical cure and was superior in achieving microbiological cure. Composite (clinical + microbiological) cure rates were superior for ceftolazone-tazobactam when considering patients whose pathogens were resistant to levofloxacin or were ESBL-positive.