Acanthamoeba spp. in Contact Lenses from Healthy Individuals from Madrid, Spain

• Published in: PloS one Vol. 11; no. 4; p. e0154246
• Main Authors: Gomes, Thiago Dos Santos, Magnet, Angela, Izquierdo, Fernando, Vaccaro, Lucianna, Redondo, Fernando, Bueno, Sara, Sánchez, Maria Luisa, Angulo, Santiago, Fenoy, Soledad, Hurtado, Carolina, Del Aguila, Carmen
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.04.2016; Public Library of Science (PLoS)
• Subjects: Acanthamoeba; Acanthamoeba - genetics; Acanthamoeba - physiology; Acanthamoeba keratitis; Acanthamoeba Keratitis - diagnosis; Acanthamoeba Keratitis - parasitology; Acanthamoeba Keratitis - prevention & control; Adolescent; Adult; Aged; Aged, 80 and over; Biofilms; Biology and Life Sciences; Care and treatment; Causes of; Child; Classification; Contact Lens Solutions - analysis; Contact lenses; Contact Lenses - microbiology; Contact Lenses - parasitology; Cornea; Deoxyribonucleic acid; Diagnosis; Disinfection - methods; Disinfection - standards; DNA; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Bacterial - isolation & purification; DNA, Protozoan - chemistry; DNA, Protozoan - genetics; DNA, Protozoan - isolation & purification; Drinking water; Environmental studies; Etiology; Female; Genotype & phenotype; Habits; Host-Parasite Interactions; Humans; Hygiene; Hygiene - standards; Infections; Keratitis; Laboratories; Male; Medicine and Health Sciences; Middle Aged; Physiological aspects; Polymerase chain reaction; Protozoans; Pseudomonas aeruginosa; Pseudomonas aeruginosa - genetics; Pseudomonas aeruginosa - physiology; Research and Analysis Methods; Ribosomal DNA; Risk analysis; Risk Factors; Samples; Sequence Analysis, DNA; Spain; Staphylococcus aureus; Staphylococcus aureus - genetics; Staphylococcus aureus - physiology; Statistical analysis; Statistical methods; Studies; Surveys and Questionnaires; Young Adult; Brazil; Canary Islands; Hong Kong; Spain
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0154246

Acanthamoeba keratitis (AK) is a painful and potentially blinding corneal infection caused by Acanthamoeba spp. In Madrid, environmental studies have demonstrated a high presence of these free-living amoebae in tap water. Since most of AK cases occur in contact lenses (CL) wearers with inadequate hygiene habits, the presence of Acanthamoeba in discarded CL has been studied and compared with other common etiological agents of keratitis, such as Pseudomonas aeruginosa and Staphylococcus aureus. One hundred and seventy-seven healthy individuals from Madrid contributed their discarded CL and answered a questionnaire on hygiene habits. DNA was extracted from the CL solution and analyzed by real-time PCR for Acanthamoeba, Pseudomonas aeruginosa and Staphylococcus aureus. These CL and their solutions were also cultured on non-nutrient agar to isolate Acanthamoeba. Among the 177 samples, Acanthamoeba DNA was detected in 87 (49.2%), P. aeruginosa DNA in 14 (7.9%) and S. aureus DNA in 19 (10.7%). Cultivable amoebae, however, were observed in only one sample (0.6%). This isolate was genotyped as T4. The habits reported by this CL owner included some recognized risk factors for AK, but in this study only the practice of "not cleaning the CL case" presented some statistical significant association with Acanthamoeba DNA presence. Detection of the investigated bacterial DNA did not demonstrate statistical significant association with the studied practices, but the presence of P. aeruginosa revealed a possible inhibition of Acanthamoeba in these samples. The PCR results suggest a high presence of Acanthamoeba spp. in healthy CL wearers from Madrid, but we can assume that CL solutions are properly disinfecting the CL since only 1.1% of the positive PCR samples correspond to viable amoebae and, after four years, only one participant reported stronger ocular problems. Nevertheless, more studies are necessary to corroborate this hypothesis.