I am allergic to penicillin, can other antibiotics be used to treat meningitis?

Yes. Meningitis is a very serious infection requiring close medical attention. Viral meningitis is most common is not treated with antibiotics. If one has bacterial meningitis, this is a medical emergency. If allergic to penicillin, other antibiotics can be used. In certain indications, one can be desensitized to penicillin.
Yes. For bacterial meningitis, you can take alternatives to penicillin. Antibiotics cannot treat meningitis caused by viruses though.