Molecular diagnosis of eosinophilic meningitis due to Angiostrongylus cantonensis (Nematoda: Metastrongyloidea) by polymerase chain reaction-DNA sequencing of cerebrospinal fluids of patients

Cerebrospinal fluid (CSF) samples from clinically diagnosed patients with detectable Angiostrongylus canto-nensis-specific antibodies (n = 10), patients with clinically suspected cases that tested negative for A. cantonensis-an-tibodies (n = 5) and patients with cerebral gnathostomiasis (n = 2) and neurocysticercosis (n = 2) were examined by a single-step polymerase chain reaction (PCR) method using the AC primers for the 66-kDa native protein gene. The PCR method detected A. cantonensis DNA in CSF samples from four of 10 serologically confirmed angiostrongyliasis cases. The PCR results were negative for the remaining CSF samples. The nucleotide sequences of three positive CSF-PCR samples shared 98.8-99.2% similarity with the reference sequence of A. cantonensis. These results indicate the potential application of this PCR assay with clinical CSF samples for additional support in the confirmation of eosinophilic meningitis due to A. cantonensis.

Polymorphic and sex-limited phosphoglucomutase in Parastrongylus cantonensis (Nematoda: Angiostrongylidae)

Phosphoglucomutase was studied by polyacrylamide gel electrophoresis in the Thailand and Hawaii isolates of Parastrongylus cantonensis (also known as Angiostrongylus cantonensis). Two loci were present. The faster-moving locus (PGM-1) was polymorphic in the Hawaii isolate, represented by two alleles - the faster-moving, less common Pgm-1A and the slower-moving, more common Pgm-1B . It was monomorphic for the faster-moving allele Pgm-1A in the Thailand isolate. The slower-moving locus (PGM-2) was invariant, with a single band of enzyme activity, in the female worms of both the Thailand and Hawaii isolates. There was no detectable enzyme activity at this PGM-2 locus in the male worms of both isolates. The non-expression or 'null' PGM-2 phenotype in the male worms was presumed to be sex- limited. The present findings differ significantly in several aspects (polymorphic locus, proportion of polymorphic loci, heterozygosity, deviations from Hardy-Weinberg expectations, sex-limited expression) from the Japan isolate of P. cantonensis reported in the literature.