Final answer:
The nurse should immediately report the finding of nuchal rigidity to the health care provider.
Step-by-step explanation:
When assessing a 53-year-old patient with bacterial meningitis, the nurse should immediately report the finding of nuchal rigidity to the health care provider. Nuchal rigidity, characterized by stiffness of the neck, is a hallmark symptom of meningitis, signaling inflammation of the meninges. It is important to report this finding promptly as it could be an early sign of worsening of the condition.