This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
[{'content': 'Mycoplasma is intrinsically resistant to: \nSelect and explain. \nA. Aminogloycosides, B. Ceftazidime, C. Macrolides, D. Doxycycline', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref. Robbins Pathology. 9th edition. Page. 1375\n\xa0\nMycoplasma\n\nSmallest extracellular bacteria.\nLack a cell wall; are very flexible and able to pass through filters which are 0.4 microns and which stop most bacteria. \u2028\nContain sterols in their cell membrane; however, they cannot synthesize sterols so mycoplasmas acquire sterols from hosts or special media. \u2028\nFacultative anaerobes except for Mycoplasma pneumoniae, which is an obligate aerobe. \u2028\nSpread by direct contact or fresh respiratory droplets. \u2028\nBind to the exterior of cells and damage epithelium from the outside. \u2028\nFastidious and slow to grow even on special cholesterol-containing medium, so diagnosis \u2028is usually clinical or serological with PCR becoming more readily available. \u2028\nCold agglutinins (autoantibodies agglutinating red blood cells at 4°C) may be present after 1 to 2 weeks of clinical disease. Titers greater than 1:32 are generally considered positive. \u2028Complement fixation is more sensitive. \u2028\nThey are resistant to cephalosporin antibiotics\nMycoplasma pneumoniae causes respiratory tract infections. \u2028\nMycoplasma hominis and Ureaplasma urealyticum appear to be involved in genitourinary tract infections', 'role': 'assistant'}]