Extensive and complex sequence diversity in mitochondrial cytochrome c oxidase subunit 1 within Necator americanus from Colombia revealed by SSCP-coupled sequencing.

In spite of the human health importance of hookworms, there has been only a small number of studies of genetic variability within Necator americanus, and none in South America. In the present study, we investigated sequence variability in a 395-bp region of the mitochondrial cytochrome c oxidase subunit 1 gene among N. americanus individuals (n=100) from humans of six villages in Colombia, employing a mutation scanning-coupled sequencing approach. Haplotypic diversity within N. americanus varied from 0.95 to 1.0 (0.9743+/-0.0068) and nucleotide diversity from 0.025 to 0.045 (0.0257+/-0.013). Nucleotide variation was reflected in nine amino acid alterations over 132 positions. The network of cox1 haplotypes (n=59) displayed a complex relationship with no apparent association between haplotype and geographical origin in Colombia. The extensive haplotypic variability detected suggests different epidemiological or disease characteristics for distinct population variants of N. americanus.