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Acanthamoeba keratitis (AK) is an infection that is mostly observed in contact lens wearers. It is often misdiagnosed causing delays in the administration of the correct treatment. The aim of this study was to report the outcome of clinical and molecular diagnosis of AK cases during the summer of 2019 in the southern region of Brazil. Three suspected cases of AK were discovered after an ophthalmic examination at a public hospital in the city of Porto Alegre. These cases were then confirmed through laboratory diagnosis (cell culture and molecular analysis by PCR and sequencing). In each of the three clinical sample cell cultures of corneal scraping and molecular analysis confirmed the presence of Acanthamoeba spp., all belonging to the morphological group II and to the genotype T4, which is the most common genotype associated with AK. In addition, Acanthamoeba spp. isolated from one of the clinical samples was found to harbor the Candidatus Paracaedibacter acanthamoeba, a bacterial endosymbiont. The presence of Ca. Paracaedibacter acanthamoeba in clinical isolates requires further research to reveal its possible role in the pathogenicity of Acanthamoeba infections. [ABSTRACT FROM AUTHOR]

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Acanthamoeba is a protist potential pathogen, capable of causing a blinding keratitis in contact lens wearers and disseminated infection, leading to granulomatous amebic encephalitis in immunocompromised individuals. This amoeba is a ubiquitous organism that has been isolated from various domestic water systems, such as cooling towers and hospital water networks. The objective of this work was to investigate the presence of Acanthamoeba in mineral water bottles marketed in Porto Alegre, southern Brazil. Positive samples were further classified at the genotype level after sequencing the ASA.S1 region of 18S rDNA gene. Six of the eight isolates belonged to T5 genotype, one to T4 genotype, and one was T11. Several genotypes have been reported worldwide as causative of pathologies in humans, including genotypes T4, T5 and T11. Overall, the widespread distribution of potentially pathogenic Acanthamoeba strains in the studied source demands more awareness within the public and health professionals, because this pathogen is emerging as a risk for human health worldwide. [ABSTRACT FROM AUTHOR]

This study compares patients with and without non-viral microbial keratitis in relation to sociodemographic variables, clinical aspects, and involved causative agent. Clinical aspects, etiology and therapeutic procedures were assessed in patients with and without keratitis that were diagnosed in an Eye Care Center in Campo Grande, MS, Brazil. Patients were divided into two groups: (a) cases: 64 patients with non-viral microbial keratitis diagnosed at biomicroscopy; and (b) controls: 47 patients with other eye disorders that were not keratitis. Labor activity related to agriculture, cattle raising, and contact lens use were all linked to keratitis occurrence (p<0.005). In patients with keratitis, the most common symptoms were pain and photophobia, and the most frequently used medicines were fourth-generation fluoroquinolones (34.4%), amphotericin B (31.3%), and natamycin (28.1%). Microbial keratitis evolved to corneal perforation in 15.6% of cases; transplant was indicated in 10.9% of cases. Regarding the etiology of this condition, 23 (42.2%) keratitis cases were caused by bacteria (Pseudomonas aeruginosa, 12.5%), 17 (39.1%) by fungi (Fusarium spp., 14.1% and Aspergillus spp., 4.7%), and 4 (6.3%) by Acanthamoeba. Patients with keratitis present with a poorer prognosis. Rapid identification of the etiologic agent is indispensable and depends on appropriate ophthalmological collection and microbiological techniques., (Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.)