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: Microbiology
[{'content': 'An organism with sterols in their cell wall is \nSelect and explain. \nA. Mycoplasma, B. Bacillus, C. Streptococcus, D. Spirillum', 'role': 'user'}, {'content': "Answer: A \nExplanation: “Mycoplasma lacks a rigid cell wall and they are bounded by a triple-layered unit membrane that contains sterols.\n” Mycoplasma PPLO - by Nocard & Roux • Smallest free-living organism • Gram-negative.highly pleomorphic organism,\nstained by Giemsa • Found in the form of elementary bodies & filaments of various size • Facultative anaerobe, require a source of cholesterol for growth\n• Media = hayflick media, Eaton's media • Colonies = biphasic with a fried egg appearance • C/F: Primary atypical pneumonia. Bullous myringitis.\nOtitis • Lab diagnosis: 1. Isolation of organism - from throat swab, respiratory secretion 2. serological diagnosis -1.\nSpecific - HI, IF. metabolic inhibition 2. Nonspecific- streptococcus MG 3.\nCold agglutination Treatment: DOC- Erythromycin (Presence of 70 S ribosome makes it susceptible to antibiotics that inhibit protein synthesis;\nbut due to the lack of cell wall they are resistant to penicillin) Remember\n• Ureaplasma ureolyticum belongs to the family mycoplasmatacea; which can hydrolyse urea & is a cause for nongonococcal urethritis •\nL forms of bacteria - are due to the loss of bacteria but they retain the biochemical & antigenic properties of present bacteria.", 'role': 'assistant'}]