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Free-living amoebae (FLA) are considered environmental pathogens and thus pose a public health threat. Their ubiquity in natural sources may magnify the potential severity of health outcomes in the future. However, less attention was given despite several probable public health risks that arise from the presence of pathogenic strains in the environment. Here, we provide epidemiological data based on investigations involving the distribution and occurrence of free-living amoebae in the Republic of the Philippines. This aims to connect data of fragmented studies of these organisms and provide potential roadmaps in FLA research in the country. The majority of the reviewed articles (n = 19) focused on characterization studies (36.8%; 7/19) while environmental isolation and isolation from biological samples had an equal frequency of 31.6% (6/19) each. There is a great disparity between the established ubiquity in environmental sources and the number of cases of FLA infections in the country. FLA-related research in the Philippines is still in its inceptive stage with several gaps to fill, which can be used to formulate policy briefs in the future regarding its isolation, identification, diagnosis, therapeutic management, and control of FLA infections in the country.

Free-living amoebae (FLA) thrive in diverse environmental conditions. The present study aimed to define the FLA distribution from the Caspian Sea as well as from hospital ward dust from Guilan, Iran. Seawater (20) and hospital ward dust samples (100) were collected from May to June 2018. Seawater samples were vacuum filtered through a 0.45 mu m pore-size membrane. Dust was collected using sterile gauze, washed with sterile distilled water, with washings collected thereafter. Washings were similarly filtered as seawater samples. FLA from the filtered material was cultivated in non-nutrient agar. Molecular analysis was performed by PCR and sequencing using specific primers for Acanthamoeba, Naegleria, and Vermamoeba/Hartmanella. Culture and PCR returned 50 and 65% positivity, respectively, for seawater samples where sequencing revealed Acanthamoeba T2, T5 and T6 genotypes and A. palestinensis and A. lenticulata, as well as N. dobsoni and N. clarki. In addition, 30% amoebic growth and 16% PCR detection were observed from hospital ward dust samples where sequencing revealed Acanthamoeba T2, T4 and T11 genotypes and A. castellanii, A. palestinensis and A. stevensoni as well as N. clarki. For both seawater and dust samples, Acanthamoeba was the dominant isolate. The detection of potentially pathogenic FLA from seawater may pose a threat to the public, while the presence of the same in dust spells threats to both hospital staff and patients, in particular, immunocompromised individuals. Public education, awareness, improved sanitation and hygiene, and the crafting of diagnostic strategies for the early detection of FLA in humans are necessary for the mitigation and management of potential human infection cases.

Background Cryptosporidiumis a waterborne global pathogen causing diarrhea primarily in infants and immunocompromised individuals. The Philippines is a tropical country susceptible to the influences of climate change and water crises. To date, the country has no existing epidemiologic data, regulation, or strategy for monitoringCryptosporidiumin freshwater systems. We, therefore, endeavored to provide evidence on the multi-spatial contamination ofCryptosporidiumin environmental aquatic matrices using low-cost, user-friendly, and sustainable strategies and submit implications on the presence ofCryptosporidiumin freshwater systems in a climate, health, and regulatory framework. Results Here, we present the microscopic detection ofCryptosporidiumoocysts in low-volume (50 mL) environmental samples of surface water (SW), sediments (BW), and substrate-associated biofilm (SAB) and in 1 L bulk SW investigated by PCR. The multi-spatial distribution ofCryptosporidiumoocysts in the low-volume (50 ml) aquatic matrices based on microscopy was highest at 69% (20/29) in SW and lowest at 50% (13/26) in BW. Immunofluorescence technique provided the highest microscopic positivity rate with 59% (17/29), 38% (10/26), and 50% (10/20) detection in SW, BW, and SAB, respectively. The detection and identification ofCryptosporidiumin 1 L bulk SW by PCR and sequence analysis was recorded in total at 21% (6/29) in sampling sites where the differential identification ofC. parvum, C. hominis,andCryptosporidiumspp. was 7% (2/29), 10% (3/29), and 3% (1/29), respectively. Conclusions We report the microscopical and first molecular epidemiologic data ofCryptosporidiumfrom the most significant environmental freshwater systems in the Philippines. The presence of the two main human and animal pathogenic speciesC. parvumandC. hominisfrom the largest lakes and major water reservoirs in the country calls for sustainable solutions in safeguarding the quality of freshwater resources in a climate, health, an

Free-living amoeba (FLA) research in the Philippines is still in its infancy but has, by far, demonstrated the presence of potentially pathogenic species.Acanthamoebamay cause sight-threatening and central nervous system infections to humans, yet its epidemiologic distribution from local environmental sources is yet to be defined. The present study aimed to provide a baseline epidemiologic distribution ofAcanthamoebaspp. in freshwater systems in the Philippines and establish potential pathogenicity of isolates through thermo-tolerance assay. A total of 63 water samples were collected from 13 freshwater systems all over the Philippine archipelago. The low-volume (50 ml) water samples were processed and cultured on non-nutrient agar lawned withEscherichia coliand observed for amoebic growth using light microscopy. Amoebic culture demonstrated 14.28% (9/63) positivity while further molecular testing of culture-positive plates usingAcanthamoeba-specific primers demonstrated 100% (9/9) confirmation ofAcanthamoebaspecies. Genotyping ofAcanthamoebaisolates revealed T1, T3, T4, T5, T7, T11, and T15 genotypes. Thermo-tolerance assay demonstrated that T5 and T7 genotypes were potentially pathogenic strains. The evidence of environmental distribution ofAcanthamoebaspp. in the freshwater systems in the Philippines and thermo-tolerance profile of isolates are significant aspects of amoeba study in public health and calls for initiatives in the dissemination of relevant information and the expansion of knowledge, awareness, and policies on pathogenic waterborne amoeba to mitigate, prevent, detect, and report cases of human infections.