Patients having TB meningitis and negative PPD skin test results appeared to be more likely to be infected by isolates having a mutant type of the PE_PGRS33 gene than patients who had no TB meningitis (OR 2.54, 95% CI [1.11-5.84]) and patients who had positive PPD-skin test results (OR 4.26, 95% CI [1.14-12.86]), respectively.