Final answer:
CSF abnormal levels of PMNs, glucose, and protein alongside methods like Gram staining and culturing tests are indicative of bacterial meningitis. Antibiotics are effective against bacteria, including N. meningitidis, identified through these methods. Elevated lactic acid in CSF also suggests bacterial etiology.
Step-by-step explanation:
Laboratory findings in cerebrospinal fluid (CSF) suggestive of bacterial meningitis include abnormal levels of polymorphonuclear neutrophils (PMNs), glucose, and protein. A count of over 10 PMNs/mm³, glucose levels under 45 mg/dL, and protein levels over 45 mg/dL indicate bacterial meningitis. Other diagnostic methods for bacterial meningitis include checking the CSF for abnormal color or turbidity, Gram staining, and culture tests to identify the presence of bacteria or fungi. Antibiotics are used to treat bacterial infections; they can target a range of bacteria, including those responsible for meningitis like Neisseria meningitidis. The oxidase test, sugar utilization, and lactic acid levels can provide additional confirmation of the specific bacteria responsible for the infection.
Gram staining, which differentiates between gram-positive and gram-negative bacteria, reveals the presence of the causative agents for approximately 80% of bacterial meningitis cases. Culture tests allow bacteria to grow in a controlled environment and may help identify the specific type of bacteria present. Finally, the presence of lactic acid in CSF is also measured as it is usually elevated in bacterial compared to viral meningitis due to increased anaerobic glycolysis in bacterial infections.