Culture Media and Growth

A 28-year-old woman presents with a 3-day history of purulent cervical discharge and dysuria. Gram stain of the cervical specimen shows gram-negative intracellular diplococci within polymorphonuclear leukocytes. Culture is being set up. Which antibiotic-supplemented selective medium is the preferred choice for isolation in this case?

A clinical microbiology laboratory receives a specimen of cerebrospinal fluid (CSF) from a 28-year-old man with suspected bacterial meningitis. The CSF shows pleocytosis with predominant neutrophils, elevated protein, and low glucose. Direct Gram stain is inconclusive. Which is the investigation of choice for rapid presumptive identification of the causative organism?

Which characteristic best distinguishes enriched media from enrichment media in the context of bacterial culture?

A 32-year-old woman from rural Maharashtra presents with a 3-week history of productive cough with blood-tinged sputum, low-grade fever in the evenings, and night sweats. Chest X-ray shows an upper lobe infiltrate with cavitation. Sputum smear microscopy is positive for acid-fast bacilli. The laboratory technician prepares culture media for isolation and identification. Which of the following media would be MOST appropriate for primary isolation and growth of the suspected organism, and why?

A 28-year-old woman from rural Maharashtra presents with a 3-week history of progressive fever, night sweats, and weight loss. Chest X-ray shows upper lobe cavitary lesions. Sputum smear microscopy is negative for acid-fast bacilli on two occasions. The clinician suspects tuberculosis but needs to confirm the diagnosis. Which culture medium should be inoculated first to maximize the recovery of Mycobacterium tuberculosis from sputum?