A 20-year-old female college student presents to the university health center with complaints of dysuria, urgency, and frequency of urination. She denies any fever, chills, or flank pain. On physical examination, mild suprapubic tenderness is noted. A urinalysis reveals the presence of leukocyte esterase and nitrites, suggestive of a urinary tract infection (UTI). Urine culture identifies Staphylococcus saprophyticus as the causative organism. Which of the following are the key identifying features of this organism?

A 22-year-old sexually active woman presents to the clinic with a 3-day history of dysuria, urinary frequency, and lower abdominal discomfort. She denies fever, chills, or flank pain. Her past medical history is unremarkable, and she reports no previous urinary tract infections. Physical examination reveals mild suprapubic tenderness without costovertebral angle tenderness. A urinalysis shows pyuria, bacteriuria, and microscopic hematuria. A urine culture grows Staphylococcus saprophyticus. Which of the following characteristics differentiates Staphylococcus saprophyticus from other coagulase-negative staphylococci?

A 26-year-old woman presents to the emergency department with complaints of fever, chills, and severe left-sided flank pain for the past 48 hours. She reports associated urinary symptoms, including dysuria, urgency, and frequency, that started a week ago. She denies vaginal discharge or abdominal pain. Her medical history is significant for recurrent UTIs, with two similar episodes in the past year. She is sexually active and uses spermicides as contraception. On examination, her temperature is 39.2°C (102.6°F), heart rate is 110 bpm, and blood pressure is 100/70 mmHg. She appears visibly uncomfortable, and palpation of the left costovertebral angle (CVA) elicits significant tenderness. Abdominal examination is unremarkable. Which of the following findings is most specific for acute pyelonephritis in this patient?

A 50-year-old male presents to the emergency department with acute onset of severe epigastric pain radiating to the back, associated with nausea and vomiting. The pain began 8 hours ago, following a heavy meal and recent alcohol consumption. On examination, he is febrile (38°C) with epigastric tenderness. Laboratory investigations reveal elevated serum amylase and lipase levels, consistent with acute pancreatitis. Imaging is considered to confirm the diagnosis and assess for complications. What is the most commonly used imaging modality for the diagnosis of acute pancreatitis?

A 50-year-old male, presented to the emergency department with a chief complaint of severe abdominal pain. The pain was described as sharp, persistent, and localized to the upper abdomen with radiation to the back. It began abruptly 12 hours prior to his arrival, and had been steadily worsening. He reported feeling nauseous but had not vomited. Laboratory results confirmed the clinical suspicion with elevated levels of amylase at 450 U/L and lipase at 600 U/L, both indicative of pancreatic inflammation. Which of the following criteria is used to assess the severity of acute pancreatitis?

Maria, a 44-year-old woman with a history of paroxysmal nocturnal hemoglobinuria (PNH) and chronic alcohol use, presents with severe abdominal pain, abdominal distention, and shortness of breath over the past week. She also reports intermittent vomiting. Physical examination reveals jaundice, a protuberant abdomen with right upper quadrant tenderness, painful hepatomegaly extending 7 cm below the costal margin, and moderate ascites. Visible dilated abdominal veins are noted when she is standing, along with bilateral pitting edema. Her vital signs show mild hypotension (BP 87/57 mmHg) and tachycardia (HR 112 bpm). Given her history of hypercoagulable conditions and physical findings, you suspect hepatic vein thrombosis (Budd-Chiari syndrome). Of the following, which is the initial test of choice in this patient to confirm the diagnosis?

A 44-year-old woman complains of severe abdominal pain and a feeling of abdominal fullness. She has been vomiting off and on for the last week. First she got abdominal pain and then the abdominal distention after two days. She gets short of breath on exertion. She has been having normal bowel movements. Her stool frequency and stool color is normal. She takes vitamin tablets and a daily oral contraceptive. Her past medical history is significant for several admissions for alcohol-related complications and paroxysmal nocturnal hemoglobinuria. Her sister had developed a deep venous thrombosis at age 48 years. Her temperature is 99 °F (37.2 °C), heart rate is 112 beats/min, blood pressure is 87/57 mm Hg, respirations are 19 breaths/min, and oxygen saturation is 96% on room air. On physical examination, she is afebrile. She has scleral icterus, otherwise eye examination is normal. She displayed shallow and rapid respirations. She has a protuberant abdomen with right upper quadrant tenderness and painful hepatic enlargement measuring 7 cm below the costal margin and a fluid wave. You can see visible dilated veins on her abdomen and back when standing. There is moderate ascites. She has 1+ pitting edema bilaterally. Rectal examination is normal. No occult blood was detected. Nervous system examination is normal. What is the most likely diagnosis in this patient?