An in vitro metronidazole susceptibility test for trichomoniasis using the InPouch TV test

Area of Science:

• Medical Microbiology
• Parasitology
• Antimicrobial Susceptibility Testing

Background:

• Metronidazole is a primary treatment for Trichomonas vaginalis infections.
• Increasing metronidazole resistance in T. vaginalis poses a clinical challenge.
• Accurate susceptibility testing is crucial for effective treatment strategies.

Purpose of the Study:

• To evaluate the InPouch TV test for determining metronidazole susceptibility in Trichomonas vaginalis isolates.
• To correlate minimum lethal concentration (MLC) values with clinical response to metronidazole treatment.

Main Methods:

• Trichomonas vaginalis isolates from 16 patients were cultured using the InPouch TV system.
• Metronidazole susceptibility was assessed by determining the minimum lethal concentration (MLC) through serial dilutions.
• Isolates were categorized as sensitive or resistant based on patient response to a standard metronidazole regimen.

Main Results:

• Metronidazole-sensitive T. vaginalis isolates had MLCs ranging from 0.4 to 3.1 µg/ml.
• Metronidazole-resistant isolates exhibited significantly higher MLCs, between 12.5 and 50 µg/ml.
• The mean MLC for resistant isolates was approximately eleven-fold higher than for sensitive isolates.

Conclusions:

• The InPouch TV test successfully differentiated metronidazole-sensitive and resistant Trichomonas vaginalis isolates.
• MLC values obtained via the InPouch TV test correlate with clinical outcomes.
• This anaerobic culture system offers a viable method for identifying metronidazole resistance in T. vaginalis.