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Household water treatment (HWT) technologies are a promising strategy for addressing the waterborne diseases burden. However, in order to be efficient, these are often limited to water quality and require it to not exceed a certain threshold of physicochemical and microbiological contamination. Additionally, some popular HWTs, such as chlorination, are related to by-product formation. Preoxidation may improve source water quality, and hydrogen peroxide (H2O2) is an oxidant that has not been deeply explored in this specific application, so it could be an innovative approach to HWTs. We investigated effects of H2O2 preoxidation in two natural source waters (surface and groundwater), spiked with a high level of microorganisms. Clarification results suggested this pretreatment may improve life of HWTs. Reduction in microbial load of groundwater was considered ineffective, but 5-min H2O2 preoxidation at 15 mg L−1 led to >4.0 log10 inactivation of Phi X174 coliphage and >3.0 of Escherichia coli in surface water. We believe this performance was increased due to the presence of catalysts in the river water. This raised the point that water quality may be not only impairing, but potentially beneficial to the main HWT and characterization is crucial prior to the implementation of any technologies.

Laboratory procedures performed in water treatment studies frequently require the characterization of (oo)cyst suspensions. Standard methods commonly used are laborious, expensive and time-consuming, besides requiring well-trained personnel to prepare samples with fluorescent staining and perform analysis under fluorescence microscopy. In this study, an easy cost-effective in situ microscope was assessed to acquire images of Giardia cysts directly from agitated suspensions without using any chemical labels or sample preparation steps. An image analysis algorithm analyzes the acquired images, and automatically enumerates and provides morphological information of cysts within 10 min. The proposed system was evaluated at different cyst concentrations, achieving a limit of detection of ~30 cysts/mL. The proposed system overcomes cost, time and labor demands by standard methods and has the potential to be an alternative technique for the characterization of Giardia cyst suspensions in resource-limited facilities, since it is independent of experts and free of consumables.

Made available in DSpace on 2021-06-25T15:05:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-18 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) There is increasing evidence showing positive association between changes in oral microbiome and the occurrence of oral squamous cell carcinoma (OSCC). Alcohol- and nicotine-related products can induce microbial changes but are still unknown if these changes are related to cancerous lesion sites. In an attempt to understand how these changes can influence the OSCC development and maintenance, the aim of this study was to investigate the oral microbiome linked with OSCC as well as to identify functional signatures and associate them with healthy or precancerous and cancerous sites. Our group used data of oral microbiomes available in public repositories. The analysis included data of oral microbiomes from electronic cigarette users, alcohol consumers, and precancerous and OSCC samples. An R-based pipeline was used for taxonomic and functional prediction analysis. The Streptococcus spp. genus was the main class identified in the healthy group. Haemophilus spp. predominated in precancerous lesions. OSCC samples revealed a higher relative abundance compared with the other groups, represented by an increased proportion of Fusobacterium spp., Prevotella spp., Haemophilus spp., and Campylobacter spp. Venn diagram analysis showed 52 genera exclusive of OSCC samples. Both precancerous and OSCC samples seemed to present a specific associated functional pattern. They were menaquinone-dependent protoporphyrinogen oxidase pattern enhanced in the former and both 3 ',5 '-cyclic-nucleotide phosphodiesterase (purine metabolism) and iron(III) transport system ATP-binding protein enhanced in the latter. We conclude that although precancerous and OSCC samples present some differences on microbial profile, both microbiomes act as iron chelators-like potentially contributing to tumor growth. Univ Fed Rio Grande do Sul, Fac Dent, Prevent & Community Dent Dept, BR-90035003 Porto Alegre, RS, Brazil Univ Sao Paulo, Fac Med Ribeirao Preto, Postgrad Program Clin Oncol Stem Cells & Cell The, BR-14049900 Ribeirao Preto, SP, Brazil Reg Blood Ctr Ribeirao Preto, Natl Inst Sci & Technol Stem Cell & Cell Therapy, Ctr Cell Based Therapy CEPID FAPESP, Mol Genet & Bioinfonnat Lab MGBL, Rua Tenente Catao Roxo 2501, BR-14049900 Ribeirao Preto, SP, Brazil Univ Sao Paulo, Ribeirio Preto Med Sch, Dept Genet, BR-14049900 Ribeirao Preto, SP, Brazil Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Entomol & Acarol, BR-13418900 Piracicaba, SP, Brazil Univ Sao Paulo, Ribeirao Preto Med Sch, BR-14049900 Ribeirao Preto, SP, Brazil Univ Sao Paulo, Sch Publ Hlth, Dept Nutr, BR-01246904 Sao Paulo, SP, Brazil Univ Sao Paulo, Sao Carlos Sch Engn, Dept Hydraul & Sanitat, BR-13563120 Sao Carlos, SP, Brazil Inst Canc Res IPEC, BR-85015430 Guarapuava, PR, Brazil Univ Estadual Centro Oeste, Dept Med, BR-85015430 Guarapuava, PR, Brazil Sao Paulo State Univ, Sch Pharmaceut Sci, Dept Food & Nutr, Araraquara, SP, Brazil Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Biochem & Immunol, Ribeirao Preto, SP, Brazil Univ Paulista, Inst Hlth Sci, Undergrad Biol Sci, Ribeirao Preto, SP, Brazil Univ Fed Parana, Grad Program Bioinformat Profess & Technol Educ S, Curitiba, Parana, Brazil Univ Fed Amapa, Dept Biol Sci & Hlth, Macapa, AP, Brazil Embrapa Southeast Livestock EMBRAPA, Sao Paulo, Brazil FARVET, Labs Invest & Desarrollo, Chincha Alta, Ica, Peru Univ San Martin de Porres, Ctr Invest Genet & Biol Mol CIGBM, Lima, Peru Para State Univ, Grad Program Parasit Biol Amazon, Belem, Para, Brazil Para State Univ, Inst Technol, Dept Elect & Biomed Engn, Belem, Para, Brazil Fundacao Ctr Controle Oncol Estado Amazonas, Dept Educ & Res, Manaus, Amazonas, Brazil Univ Fed Goias, Inst Pathol Trop & Publ Hlth, Goiania, Go, Brazil Univ Sao Paulo, Sch Dent Ribeirao Preto, Dept Oral Maxillofacial Surg & Periodontol, Ribeirao Preto, SP, Brazil Univ Sao Paulo, Sch Arts Sci & Humanities, Sao Paulo, Brazil Blood Ctr Ribeirao Preto, Ctr Cell Based Therapy CEPID FAPESP, Mol Genet & Bioinformat Lab MGBL, Rua Tenente Catao Roxo 2501, BR-14051140 Ribeirao Preto, SP, Brazil Sao Paulo State Univ, Sch Pharmaceut Sci, Dept Food & Nutr, Araraquara, SP, Brazil CNPq: 465539/2014-9 FAPESP: 2013/08135-2 FAPESP: 17/23205-8 FAPESP: 19/08528-0

A system composed of cartridge membrane filters (25 μm, 10 μm and 1 μm opening size), UVC-lamp and chlorinator was constructed and tested with high turbidity water (up to 236 NTU). The proposed system treated around 180 L day−1 of river water and the following parameters were analysed: pressure drop in filters, turbidity, apparent colour, true colour, Escherichia coli, total coliforms (TC), UV 254nm transmittance, UV 254nm absorbance and total organic carbon in both raw and treated water. The study was conducted in three phases. In Phase 1, the raw water was rested for 24 h in a settling tank before filtration in a 10 μm cartridge filter followed by one cartridge of 1 μm, a UVC-lamp (17 W) and manual chlorination. In Phase 2, a 25 μm filter was added before the 10 μm filter. In Phase 3, a blanket filtration step was added before the raw water entered the rest tank. The filtration trials lasted 7, 21 and 69 days in Phases 1, 2 and 3, respectively. The turbidity reduction of the system ranged from 30% to 93%. Disinfection by UVC-lamp was able to inactivate E. coli up to 5.00log, however the TC reduction was lower (up to 4.24log). The final manual chlorination with a dose of 3 mg L−1 of sodium hypochlorite increased the reduction of TC (up to 5.94log), regardless of water turbidity. The system was effective in improving water quality aimed at implantation in rural communities for domestic use at household level.

This study evaluated the impact of a 50% reduction of filter media depth in Household Slow Sand Filters (HSSFs) on continuous flow to remove physicochemical and microbiological parameters from river water. Furthermore, simple pre-treatment and disinfection processes were evaluated as additional treatments. Two filter models with different filtration layer depths were evaluated: a traditional one with 50 cm media depth (T-HSSF) and a compact one (C-HSSF) with 25 cm. HSSFs were fed with pre-treated river water (24-h water sedimentation followed by synthetic fabric filtration) for 436 days at a constant filtration rate of 0.90 m3 m−2 day−1 with a daily production of 48 L day−1. Sodium hypochlorite (2.0 mg L−1 of NaOCl 2.5% for 30 min) was used to disinfect the filtered water. Water samples were analysed weekly for parameters such as turbidity, organic matter, colour and E. coli, among others. Removal of protozoan cysts and oocysts by the HSSFs were also evaluated. After pretreatment, turbidity from the HSSF river water was reduced to 13.2 ± 14.6 NTU, allowing the filters to operate. Statistical analysis indicated no significant difference (p > 0.05) between T-HSSF and C-HSSF efficiencies in all evaluated parameters throughout operation time. Hence, media depth reduction did not hinder continuous HSSF performance for almost all the evaluated parameters. However, it may have affected Giardia cysts retaining, which passed through the thinner media on one evaluation day. Disinfection was effective in reducing remaining bacteria from filtered water; however, it was ineffective to inactivate protozoa. The reduction in the filtration layer did not affect the overall filtered water quality or quantity showing that a compact HSSF model may be a viable option for decentralized water treatment.

Giardia duodenalis and Cryptosporidium spp. are two of the most prominent aetiological agents of waterborne diseases. Therefore, efficient and affordable methodologies for identifying and quantifying these parasites in water are increasingly necessary. USEPA Method 1623.1 is a widely used and validated protocol for detecting these parasites in water samples. It consists of a concentration step, followed by parasite purification and visualization by immunofluorescence microscopy. Although efficient, this method has a high cost particularly due to the immunomagnetic separation (IMS) step, which is most needed with complex and highly contaminated samples. Based on this, the present study aimed to determine whether it is possible to maintain the efficiency of Method 1623.1 while reducing the amount of beads per reaction, using as a matrix the challenge water recommended by the World Health Organization. As for Giardia cysts, a satisfactory recovery efficiency (RE) was obtained using 50% less IMS beads. This was evaluated both with a commercial cyst suspension (56.1% recovery) and an analytical quality assessment (47.5% recovery). Although RE rates obtained for Cryptosporidium parvum did not meet Method 1623.1 criteria in any of the experimental conditions tested, results presented in this paper indicated the relevance of the described adaptations, even in challenge water. HIGHLIGHTS The high cost of current protozoa detection methods limits their widespread use in limited settings.; Immunomagnetic separation improves detection by cleaning the sample.; Recovery efficiency is maintained for Giardia duodenalis with 50% less beads.; Organisms adhering to beads after dissociation may impact recovery levels.

Household Water Treatment and Safe Storage (HWTS) are recommended to supply the demand for drinking water in communities without conventional water supply systems. However, there is a lack of long-term laboratory studies regarding such technologies. We evaluated the contributions of each step of a multi-barrier system with pretreatment (sedimentation and fabric filtration), filtration in Household Slow Sand Filters (HSSFs) and disinfection (sodium hypochlorite) treating surface water for more than 14 consecutive months. Removal of turbidity, colour, organic matter, coliform group bacteria and protozoa were evaluated. Two HSSF models were compared, one with a diffuser vessel (HSSF-d) and one with a gravity float equipped vessel (HSSF-f). Correlations between efficiency and operational parameters were assessed. Overall, the multi-barrier system removed more than 90% of turbidity and more than 3.5 log of Escherichia coli. HSSF removed up to 3.0 log of Giardia spp. and 2.4 log of Cryptosporidium spp. HSSF-f presented significantly higher removal rates for turbidity, apparent colour and E. coli. Disinfection resulted in water with E. coli concentration lower than 1 CFU 100mL−1, however it was not able to inactivate protozoa. The evaluated system was able to reduce microbiological risks from water and could indeed be an alternative to communities that depend on surface water as their main source of supply. Nevertheless, further studies are recommended to include a low-cost disinfectant for protozoa inactivation.

Os nematódeos dos gêneros Toxocara e Toxascaris são identificados, tradicionalmente, com base nos aspectos morfológicos, entretanto a diversidade genética entre esses parasitos é reconhecida, sendo a análise precisa dessa variação é necessária para o entendimento da biologia desses organismos. Esse trabalho teve como objetivos estabelecer relações filogenéticas e filogeográficas entre espécimes de Toxocara canis, Toxocara cati, Toxocara malaysiensis e Toxascaris leonina, e comparar os resultados das técnicas morfológica e moleculares. Foram coletados 436 helmintos adultos e quatro “pools” de ovos de canídeos e felídeos, procedentes de oito países. Os parasitos foram analisados por microscopia estereoscópica, pela Reação em Cadeia da Polimerase (PCR) e “Restriction Fragment Lenght Polymorfism” (PCR-RFLP). Os primers TOXCOIF3 e TOXCOIF2 foram desenhados para amplificar 490 pares de base do gene mitocrondrial Cox1 e a PCR-RFLP foi realizada utilizando-se a enzima MseI. As relações filogenéticas entre os isolados foram observados no filograma e pelo cálculo das taxas de variabilidade genotípicas (distância filogenética). Dos 313 parasitos adultos provenientes de cães, 309 foram identificados, por microscopia, como T.canis e quatro como T. leonina. Dos 123 oriundos de gatos, 118 foram identificados como T. cati, quatro T. malaysiensis e um T. leonina. Dentre os “pools” de ovos, os três de leoas foram identificados como T. leonina e o de cão como T. canis. A PCR em todas as amostras analisadas (n=440) apresentou falha de 3,6%. Das amostras amplificadas (n=424) 72 foram selecionadas para o sequenciamento. Com exceção de três amostras, duas provenientes de gato foram caracterizadas como T. canis, e uma proveniente de cão como T. cati, todas as restantes foram caracterizadas em concordância com os respectivos hospedeiros. Das 424 amostras submetidas a PCR-RFLP, 351 foram identificadas como T. canis/T.leonina, 70 como T. cati e três como T. malaysiensis. Essa técnica apresentou resultados semelhantes ao sequenciamento. Foram observadas homologia e variação genotípica nas espécies, sendo a maior 6,6%. Relações filogeográficas, dentro das espécies, puderam ser observadas pelo filograma. Entre as técnicas, observou-se 9,7% de incongruência de resultados entre microscopia e sequenciamento e 0,9% entre microscopia e PCR-RFLP. Entre as técnicas moleculares, considerou-se somente T. cati e T. malaysiensis, o que significou 100% de concordância entre resultados. A partir dos achados desse trabalho, conclui-se que alguns isolados, da mesma espécie, apresentaram variabilidade intragenotípica; Sequências homólogas foram identificadas em diferentes países, sugerindo a ocorrência de fluxo gênico; A procedência geográfica teve relação direta com a variação genética dos parasitos; T. canis e T. cati apresentaram taxa de variabilidade semelhante às de T. cati e T. leonina; E as três técnicas utilizadas apresentaram resultados que indicam a preferência de T. canis, T. cati e T. malaysiensis por determinados hospedeiros. The nematodes of the genus Toxocara and Toxascaris are identified, traditionally, based on the morphologic aspects, however the genetic diversity among these parasites is recognized, being an accurate analysis of this variation necessary for the understanding of the biology of these organisms. This work aimed to establish the phylogenetic and phylogeographic relationships among specimens of Toxocara canis, Toxocara cati, Toxocara malaysiensis and Toxascaris leonina and to compare the results given by the morphologic and molecular techniques. In total, 436 helminths adults and four pools of eggs were collected from canids and felines from eight countries. The parasites were analyzed by stereoscopic microscopy, by Polymerase Chain Reaction (PCR) and by Restriction Fragment Length Polymorphism (PCR-RFLP). Primers TOXCOIF3 and TOXCOIR2 were designed in order to amplify 90pb of the mitochondrial gene Cox1, and the PCR-RFLP using the enzyme MseI could discriminate between these four species. The phylogenetic relationships among the isolates were observed in the phylogram and by the genetic variability (phylogenetic distance) rates. Of the 313 parasites adults, from dogs, 309 were identified, by microscopy, as T. canis and four as T. leonina. Of 123 originating from cats 118 were identified as T. cati, four as T. malaysiensis and one as T. leonina. Among the pools the three from lions were identified as T. leonina and that of dog as T. canis. PCR in all analyzed samples (n=440) failed in 3,6%. Of the amplified samples (n=424) 72 were selected to sequencing. With the exception of three samples, two from cats, were characterized as T. canis and one from dog as T. cati, all remaining were identified in agreement with their respective hosts. Of the 424 samples submitted to PCR-RFLP 351 were identified as T. canis/T.leonina, 70 as T. cati and three as T. malaysiensis. This technique presented similar results to sequencing. Homology and genotypic variation were observed within species, being the largest one 6.6%. Phylogeographic relationships within species could be observed by the phylogram. Among the techniques it was observed 9,7% of incongruence in the results between microscopy and sequencing, and 0,9% between microscopy and PCR-RFLP. Between the molecular techniques, it was considered only T. cati and T. malaysiensis which meant 100% of agreement. Based on the findings, of this study, it was concluded that some isolates of the same specie presented intragenotipic variability; Homologous sequences were identified in different countries, suggesting the occurrence of gene flow; The geographic origin was directed related to the genetic variation of the parasites; T. canis and T. cati presented variability rates similar to T. cati and T. leonina; And the three techniques used, herein, showed results that indicate a preference of T. canis, T. cati and T. malaysiensis for certain hosts. Tese (Doutorado)

This study aimed to evaluate the efficiency of four household slow sand filter (HSSF) models for the removal of microorganisms from river water throughout the development of their biological layers (schmutzdecke). Two models were designed to be operated continuously (HSSF-CC and HSSF-CT) and two intermittently (HSSF-ID and HSSF-IF). Filters were fed daily with 48 L pre-treated river water (24 h sedimentation followed by filtration through a non-woven synthetic blanket). Water samples were quantified by coliform group bacteria and analysed by bright field microscopy to visualize the microorganisms. Total coliform reduction was between 1.42 ± 0.59 log and 2.96 ± 0.58 log, with continuous models showing a better performance (p-values < 0.004). Escherichia coli reduction varied from 1.49 ± 0.58 log to 2.09 ± 0.66 log and HSSF-IF, HSSF-CC and HSSF-CT presented a similar performance (p-values > 0.06), slightly better than the one presented by HSSF-ID (p-value=0.04). Microorganisms, such as algae, protozoa and helminths were detected by microscopy in raw water and pre-treated water. Algae were the most significant group in these samples, although they were not visualized by bright field microscopy in the filtered water. Results showed the potential of HSSF in microbiological risk reduction from river water, which increases the range of point-of-use water treatments in rural communities. However, additional studies of the HSSF biological layer must be performed.

Household, or point-of-use (POU), water treatments are effective alternatives to provide safe drinking water in locations isolated from a water treatment and distribution network. The household slow sand filter (HSSF) is amongst the most effective and promising POU alternatives available today. Since the development of the patented biosand filter in the early 1990s, the HSSF has undergone a number of modifications and adaptations to improve its performance, making it easier to operate and increase users' acceptability. Consequently, several HSSF models are currently available, including those with alternative designs and constant operation, in addition to the patented ones. In this scenario, the present paper aims to provide a comprehensive overview from the earliest to the most recent publications on the HSSF design, operational parameters, removal mechanisms, efficiency, and field experiences. Based on a critical discussion, this paper will contribute to expanding the knowledge of HSSF in the peer-reviewed literature.