# Single nucleotide polymorphisms associated with benzimidazole resistance of the β-tubulin isotype 1 gene in Ascaris lumbricoides isolated in South Africa

## TL;DR

This study looked for genetic mutations in a South African population of Ascaris worms that could lead to drug resistance, but found no such mutations in the small sample tested.

## Contribution

The study provides baseline genetic data on benzimidazole resistance markers in A. lumbricoides from South Africa.

## Key findings

- No mutations were detected in the β-tubulin isotype 1 gene at codons F167Y, E198A, and F200Y.
- All samples showed the homozygous wild-type genotype for the studied SNPs.
- The study highlights the need for larger sample sizes to confirm the absence of mutations.

## Abstract

Ascariasis is a parasitic infection caused by Ascaris lumbricoides and infects over 1.2 billion people worldwide. Benzimidazole (BZ) drugs remain the standard treatment in large-scale deworming programs globally. The prevalence of Single Nucleotide Polymorphisms (SNPs) in the β-tubulin gene of A. lumbricoides (F200Y, E198A and F167Y) is increasing due to the widespread use of BZ drugs.

To investigate the prevalence of the above-mentioned SNPs in a South African adult population.

This was a sub-study of the main cross-sectional study with participants (n = 414) who had been recruited from five public health clinics in the peri‑urban areas South of Durban, KwaZulu-Natal, South Africa. For the current study, a purposive selection of 20 stool samples that were positive for A. lumbricoides eggs was made. A. lumbricoides worm extracts (n = 4) were used as a positive control. Sanger sequencing and RFLP-PCR were used to identify the presence of mutations.

No mutations were detected, and all genotypes observed at codons F167Y, E198A and F200Y were the homozygous wild-type genotype.

Although no mutations were found in this small study, the potential occurrence of mutations in a larger sample subset cannot be ruled out.