Question 378
{"accessible":false,"alternatives":[{"id":1871,"text":"Enterobacter cloacae"},{"id":1872,"text":"Escherichia coli"},{"id":1873,"text":"Haemophilus influenzae"},{"id":1874,"text":"Klebsiella pneumoniae "},{"id":1875,"text":"Pseudomonas aeruginosa"}],"archived":false,"correctAlternativeId":1872,"explanation":"\u003cp\u003eThe most commonly implicated organisms are from the gastrointestinal tract:\u003c/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cem\u003eE. coli\u0026nbsp;\u003c/em\u003e(most common)\u003c/li\u003e\n\u003cli\u003e\u003cem\u003eKlebsiella spp.\u003c/em\u003e\u003c/li\u003e\n\u003cli\u003e\u003cem\u003eProteus spp.\u003c/em\u003e\u003c/li\u003e\n\u003cli\u003e\u003cem\u003eEnterobacter spp.\u003c/em\u003e\u003c/li\u003e\n\u003cli\u003e\u003cem\u003ePseudomonas spp.\u003c/em\u003e\u003c/li\u003e\n\u003cli\u003e\u003cem\u003eHaemophilus influenzae\u003c/em\u003e\u003c/li\u003e\n\u003c/ul\u003e\u003cp\u003eInfection gains access to the upper urinary tract by passing retrograde up the ureter from the bladder, facilitated by virulence factors which allow bacteria to adhere to the urothelium (e.g. adhesin P) and inhibit ureteric peristalsis (endotoxins). The infection then passes into the collecting tubules and results in an interstitial nephritis, with resulting alterations in renal filtration and blood flow in the affected region. Localized ischemia secondary to inflammatory changes results in altered imaging and may eventually lead to necrosis and scar.\u003c/p\u003e","id":378,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2094","nextQuestionPath":null,"relatedArticles":[],"alsoUsedIn":[{"id":621,"kind":"Course","title":"Radiopaedia 2020 - Lectures Only - page 621","link":"https://radiopaedia.org/courses/radiopaedia-2020-exclusive/pages/621"},{"id":621,"kind":"Course","title":"2020 Virtual Conference Private Use - page 621","link":"https://radiopaedia.org/courses/2020-virtual-conference-private-use/pages/621"},{"id":683,"kind":"Course","title":"Abdominal Emergency Radiology Course - page 683","link":"https://radiopaedia.org/courses/abdominal-emergency-radiology-course-online/pages/683"},{"id":683,"kind":"Course","title":"2020 Virtual Conference Private Use - page 683","link":"https://radiopaedia.org/courses/2020-virtual-conference-private-use/pages/683"}],"stem":"\u003cp\u003eWhat is the most common cause of bacterial pyelonephritis?\u0026nbsp;\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/378"}],"attemptsPercentages":[{"alternativeId":"1872","percentage":89},{"alternativeId":"1874","percentage":3},{"alternativeId":"1871","percentage":3},{"alternativeId":"1875","percentage":4},{"alternativeId":"1873","percentage":1}],"promptToLogin":false,"questionManager":false,"articleId":"acute-pyelonephritis"}