OBJECTIVES

Acanthamoeba spp. are free-living amoebae commonly found in aquatic environments, with pathogenic genotypes capable of causing severe diseases such as acanthamoeba keratitis and granulomatous amoebic encephalitis. Environmental factors, particularly pH, influence their survival and distribution. Tadlac Lake located at Los Baños, Laguna, Philippines is a Class C freshwater body used for aquaculture, recreation, and irrigation. To date, no study has specifically assessed Acanthamoeba colonization in Tadlac Lake.

METHODS

In this study, detection of the presence of Acanthamoeba spp. and evaluation of pH as a potential factor influencing their persistence in Tadlac Lake was conducted. One-time sampling was conducted from nine sites of the lake. Surface water samples were collected at a depth of 10–20 cm, filtered through 1.2 μm glass microfiber filters, and cultured on non-nutrient agar plates lawned with live Escherichia coli. Plates were incubated at 30°C for 14 days and examined daily under light microscopy, while pH was measured in situ.

RESULTS

Cyst-like structures resembling amoebae were observed, but these did not exhibit definitive Acanthamoeba morphology under light microscopy. No Acanthamoeba spp. were confirmed and the recorded pH levels ranged from 8.72 to 10.51, exceeding the optimal growth range (7.0–9.0) reported for the organism.

CONCLUSION

Findings of this study suggest alkaline conditions may have inhibited the proliferation and persistence of Acanthamoeba spp. in the lake. These findings highlight pH as a potential limiting factor for Acanthamoeba survival in alkaline freshwater bodies and underscore the importance of integrating physicochemical monitoring into pathogen surveillance frameworks.

Plants ; Acanthamoeba Keratitis

Background and Objective: Retinoblastoma is one of the most common intraocular cancers among children usually caused by the loss of retinoblastoma protein function. Despite being a highly heritable disease, conventional diagnostic and prognostic methods depend on clinical examination, with limited consideration of cancer genetics in the standard of care. CD133, KRT19, and MUC1 are commonly explored genes for their utility in liquid biopsies of cancer including lung adenocarcinoma. To date, there are few extensive molecular studies on retinoblastoma in Filipino patients. To this end, the study aimed to describe the copy number of CD133, KRT19, and MUC1 in retinoblastoma samples from a Filipino patient and quantitate the respective expression level of these genes. Methods: Hematoxylin & Eosin (H&E) staining was utilized to characterize the retinoblastoma tissue while fluorescence in situ hybridization (FISH) using probes specific to CD133, KRT19, and MUC1 was performed to determine the copy number of genes in retinoblastoma samples from a Filipino patient (n = 1). The gene expression of CD133, MUC1, and KRT19 was quantitated using RT-qPCR. Results: The H&E staining in the retinoblastoma tissue shows poorly differentiated cells with prominent basophilic nuclei. CD133 was approximately 1.5-fold overexpressed in the retinoblastoma tissue with respect to the normal tissue, while MUC1 and KRT19 are only slightly expressed. Multiple intense signals of each probe were localized in the same nuclear areas throughout the retinoblastoma tissue, with high background noise. Conclusion These findings suggest that CD133 is a potential biomarker for the staging and diagnosis of retinoblastoma in Filipino cancer patients. However, further optimization of the hybridization procedures is recommended.
Retinoblastoma ; Biomarkers ; In Situ Hybridization