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Pathogenic Free-Living Amoebae Isolated From Contact Lenses of Keratitis Patients
Elham Hajialilo1, Maryam Niyyati2, Mohammad Solaymani3
1Department of Medical Parasitology and Mycology, School of Public health, Tehran University of Medical Sciences, Tehran, Iran.
Background:
Free-living amoeba (FLA)-related keratitis is a progressive infection of the cornea with poor prognosis. The present study aimed to investigates the contact lenses of patients with keratitis for pathogenic free-living amoebae.
Methods:
Overall, 62 contact lenses and their paraphernalia of patients with keratitis cultured and tested for the presence of free-living amoebae using morphological criteria. Unusual plates including plates containing mix amoebae and Vermamoeba were submitted to molecular analysis.
Results:
Out of 62 plates, 11 revealed the outgrowth of free living amoeba of which 9 were Acanthamoeba, one plates contained mix amoebae including Acanthamoeba and Vermamoeba and one showed the presence of Vermamoeba. These two latter plates belonged to patients suffered from unilateral keratitis due to the misused of soft contact lenses. One of the patients had mix infection of Acanthamoeba (T4) and V. vermiformis meanwhile the other patient was infected with the V. vermiformis.
Conclusion:
Amoebic keratitis continues to rise in Iran and worldwide. To date, various genera of free-living amoebae such as Vermamoeba could be the causative agent of keratitis. Soft contact lens wearers are the most affected patients in the country, thus awareness of high-risk people for preventing free-living amoebae related keratitis is of utmost importance.
Insights
Free-living amoebae (FLA) can cause serious eye infections like keratitis, especially in soft contact lens wearers. This study found Acanthamoeba and Vermamoeba species on contact lenses of infected patients, highlighting the need for awareness.
Area of Science:
- Ophthalmology
- Microbiology
- Infectious Diseases
Background:
- Free-living amoeba (FLA)-related keratitis is a severe corneal infection with a poor prognosis.
- Contact lens misuse is a significant risk factor for FLA keratitis.
Purpose of the Study:
- To investigate contact lenses of keratitis patients for pathogenic free-living amoebae.
- To identify the specific amoebic species causing keratitis in soft contact lens wearers.
Main Methods:
- Cultured and morphologically analyzed 62 contact lenses and paraphernalia from keratitis patients.
- Utilized molecular analysis for plates with mixed amoebae or Vermamoeba.
Main Results:
- Free-living amoebae were detected on 11 out of 62 analyzed plates.
- Acanthamoeba was identified in 9 cases, Vermamoeba in one, and a mixed Acanthamoeba/Vermamoeba infection in another.
- Two cases of unilateral keratitis were linked to soft contact lens misuse, involving V. vermiformis and a mixed infection.
Conclusions:
- Amoebic keratitis incidence is increasing globally and in Iran.
- Vermamoeba, alongside Acanthamoeba, can be a causative agent of keratitis.
- Soft contact lens wearers are particularly vulnerable, emphasizing the importance of public awareness for prevention.
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