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Published on: July 9, 2012
Resistance towards metronidazole in Blastocystis sp.: A pathogenic consequence
Arutchelvan Rajamanikam1, Ho Shiaw Hooi2, Madhav Kudva3
1Depatment of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Metronidazole treatment may unexpectedly increase the pathogenicity of Blastocystis sp. parasites, including enhanced growth and cancer cell proliferation. This finding necessitates a reevaluation of current treatment strategies for gastrointestinal infections caused by this protozoan.
Area of Science:
- Microbiology
- Parasitology
- Gastroenterology
Background:
- Blastocystis sp. is a common protozoan parasite causing gastrointestinal issues.
- Metronidazole, a primary treatment, often shows inefficacy and variable resistance.
- The impact of metronidazole on Blastocystis sp. pathogenicity across different host gut environments remains unclear.
Purpose of the Study:
- To investigate the in vitro effect of metronidazole on the pathogenic potentials of Blastocystis sp. from urban and indigenous populations.
- To analyze changes in parasite growth, apoptosis, protease activity, and cancer cell proliferation after metronidazole treatment.
Main Methods:
- Blastocystis sp. ST 3 isolates from symptomatic and asymptomatic individuals were exposed to varying metronidazole concentrations.
- Parasite growth, apoptotic rates, cysteine protease activity, and cancer cell proliferation were assessed post-treatment.
- Comparative analysis was performed between urban and indigenous isolates.
Main Results:
- Metronidazole treatment (0.001 mg/ml) increased Blastocystis sp. numbers, particularly amoebic forms in urban isolates.
- Post-treatment isolates exhibited higher apoptosis rates and significantly increased cysteine protease activity.
- Metronidazole-resistant Blastocystis sp. demonstrated enhanced cancer cell proliferation.
- Pathogenicity differences between urban and indigenous isolates were not significant post-treatment.
Conclusions:
- Metronidazole treatment can paradoxically enhance the pathogenic potential of Blastocystis sp., including increased proliferation and cancer cell invasiveness.
- The study highlights the need to reassess metronidazole treatment protocols for Blastocystis sp. infections.
- Findings suggest metronidazole may alter parasite virulence factors, necessitating further investigation into treatment efficacy and host-parasite interactions.
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