Bacterial diversity and antibiotic resistance from the water source to the tap

Water is one of the most important habitats for bacteria in the environment. The continuous flux in the urban water cycle carries water through many places, dragging bacteria and numerous chemical contaminants. This makes of water one of the most important vehicles, not only for the dissemination of the chemical substances, but also for the dissemination of organisms and, consequently, the respective resistance genes in the environment. The main goal of this study was to investigate if drinking water production and distribution could represent a hotspot for the proliferation, selection or incoming of antibiotic resistant bacteria, and the likelihood of these organisms to reach the final consumer, via tap water. In order to meet this objective, the study was planned aiming the tracking of bacterial communities and individual isolates from the source to the tap. Firstly, the abundance and diversity of bacteria in raw, treated and final (tap) water was characterized using culture-dependent and culture-independent (16S rRNA-DGGE) approaches. Both approaches showed that the water treatment reduced the bacterial counts, diversity and cultivability, promoting also a shift in the cultivable bacterial community from predominantly Gram-negative to predominately Gram-positive bacteria. Nevertheless, this effect was reverted, and in tap water Gram-negative bacteria became predominant. Moreover, in tap water total and cultivable bacteria counts were higher than in the disinfected water collected from the distribution system. These results suggest the occurrence of bacterial regrowth and/or biofilm formation over the distribution system or at tap level. Although changes in the bacterial community structure over the water circuit were observed, the predominant phylum detected, by 16S rRNA-DGGE, was the same in all the sampling points – Proteobacteria (mainly of classes Alpha, Beta and Gamma). Culture-dependent and culture-independent approaches were compared to assess which groups might be overlooked by cultivation procedures. In order to have a clear evidence of the bacterial groups which could be overlapped using those procedures, culture-dependent and two culture-independent (16S rRNA gene based DGGE and 454 pyrosequencing) methods were compared for their ability to survey the bacterial diversity of a sample. Such a comparison showed that although the different methods detected the same predominant phyla, different bacteria were targeted. Thus, besides the previous expectation that culture-independent methods would detect more bacterial groups than cultivation methods, it was also concluded that both approaches target different bacterial populations. Based on the study of the bacterial diversity, mainly of cultivable bacteria, and in the literature available, two of the most relevant taxonomic groups detected in drinking waters, due to the widespread distribution and/or abundance, were further studied. Thus, Sphingomonadaceae and Pseudomonas spp. isolated from the source to the tap were studied for species diversity, intra-species variability and potential to spread antibiotic resistance. Although members of the same species were detected in different sampled sites, the same genotype was never detected in raw water and in tap water. According to these results, the hypothesis that bacteria detected in tap water had origin in the water source had to be rejected. Other hypotheses, namely the occurrence of regrowth in water pipelines or taps or an external contamination downstream the sampled sites in the distribution system, emerged from this study. Additionally, the analysis of the antibiotic resistance profiles confirmed that both Sphingomonadaceae and Pseudomonas spp. are potential reservoirs of antibiotic resistance. Nevertheless, clear evidences of horizontal gene transfer were not obtained in this study. Indeed, antibiotic resistance patterns were mainly species-, rather than site- or strain-related, suggesting the importance of vertical resistance transmission in water bacteria. Some antibiotic resistance phenotypes were observed in tap water but not upstream. Examples of this situation were the resistance phenotypes to ampicillin-sulbactam, piperacillin plus tazobactam-pyocyanin, imipenem, ceftazidime, cefepime, gentamicin or tobramycin in Sphingomonadaceae, or to streptomycin and rifampicin in Pseudomonas spp. Cultivation-independent methods show invariably that most of the bacteria in a community are unknown, which means that were never cultivated, characterized and integrated in a validly named taxonomic group. Bacterial taxonomy can have a contribution to gradually narrow the tranche corresponding to the unknown bacteria. In this study a new species name Bacillus purgationiresistens sp. nov. was proposed, based in a single isolate recovered from treated water. Drinking water was confirmed as a potential hotspot for the spreading of antibiotic resistant bacteria, with emphasis on the transfer environment-humans.A água é um dos habitats mais importantes para as bactérias no ambiente. O fluxo contínuo da água, nomeadamente ao longo do seu ciclo urbano, faz com que chegue a muitos locais, arrastando microrganismos e inúmeros contaminantes químicos. Isto faz da água um dos veículos mais importantes para a disseminação no ambiente, não só de substâncias químicas, mas também de bactérias e, consequentemente, dos respetivos genes de resistência. O principal objetivo deste estudo foi investigar se a produção e distribuição de água de consumo poderá representar um ponto-chave para a proliferação, seleção e entrada de bactérias resistentes a antibióticos, bem como a probabilidade de estes organismos chegarem até ao consumidor final, através da água da torneira. O estudo foi planeado para atingir esse objectivo, através do rastreio de comunidades bacterianas e de isolados individuais desde a captação até à torneira. Inicialmente, a abundância e diversidade bacteriana em água não-tratada, tratada e final (torneira) foi caracterizada através do uso de abordagens dependentes e independentes (16S rRNA-DGGE) de cultivo. Ambas as abordagens mostraram que o tratamento da água reduziu as contagens, a cultivabilidade e a diversidade bacteriana, promovendo também a alteração da comunidade bacteriana cultivável de predominantemente bactérias Gram-negativas para predominantemente Gram-positivas. No entanto, este efeito foi revertido, e na água de torneira as bactérias Gram-negativas voltaram a ser predominantes. Adicionalmente, na água de torneira as contagens de microrganismos totais e de bactérias cultiváveis foram mais elevadas do que para a água tratada recolhida no sistema de distribuição. Estes resultados sugerem a ocorrência de reactivação e crescimento bacteriano e/ou a formação de biofilme ao longo do sistema de distribuição e ao nível das torneiras. Apesar de se terem observado alterações na estrutura da comunidade bacteriana ao longo do circuito da água, o filo detetado como predominante, por 16S rRNA-DGGE, foi o mesmo em todos os pontos de amostragem – Proteobacteria (principalmente das classes Alpha, Beta e Gamma). Abordagens dependentes e independentes de cultivo foram comparadas para avaliar quais os grupos que poderão ser ignorados quando se caracterizam comunidades bacterianas usando métodos de cultivo. De forma a ter uma evidência mais clara dos grupos bacterianos que se sobrepõem usando as duas abordagens, o método dependente e dois independentes de cultivo (DGGE e pirosequenciação 454 com base no gene 16S rRNA) foram comparados quanto à sua capacidade para detectar a diversidade bacteriana de uma amostra de água. Esta comparação mostrou que apesar de os diferentes métodos identificarem o mesmo filo como sendo predominante, as bactérias detetadas eram diferentes. Assim, além da expectativa anterior de que os métodos independentes de cultivo detetassem mais grupos bacterianos do que os dependentes de cultivo, concluiu-se também que as duas abordagens incidem sobre diferentes populações bacterianas. Com base no estudo da diversidade bacteriana, principalmente das bactérias cultiváveis, e no que se encontra disponível na literatura, dois grupos taxonómicos de grande relevância em água de consumo, devido à sua ampla distribuição e/ou abundância, foram estudados. Assim, Sphingomonadaceae e Pseudomonas spp., isoladas desde a captação até à torneira foram caracterizadas para a diversidade de espécies, a variabilidade intra-espécie e o potencial para propagar resistências a antibióticos. Apesar de membros da mesma espécie terem sido identificados em diferentes locais, o mesmo genótipo nunca foi detetado na captação ou sistema de distribuição e em água de torneira. De acordo com estes resultados, a hipótese de que as bactérias detetadas em água de torneira teriam origem na água da captação teve de ser rejeitada. Contudo, este estudo conduz a outras hipóteses, nomeadamente a ocorrência de reactivação e crescimento microbiano nas canalizações ou torneiras, ou de uma contaminação externa, a jusante dos pontos amostrados no sistema de distribuição. Adicionalmente, a análise dos perfis de resistência a antibióticos confirmaram que tanto Sphingomonadaceae como Pseudomonas spp. são potenciais reservatórios de resistência a antibióticos. No entanto, este estudo não permitiu obter evidências claras da ocorrência de transferência horizontal de genes. Na verdade, os padrões de resistência a antibióticos relacionaram-se principalmente com a espécie e não com o local ou estirpe, sugerindo a importância da transmissão vertical de resistências em bactérias da água. Alguns fenótipos de resistência a antibióticos detectados em água de torneira não foram detetados a montante. São exemplos os fenótipos de resistência a ampicilina-sulbactame, piperacilina e tazobactam-piocianina, imipenemo, ceftazidima, gentamicina ou tobramicina nas Sphingomonadaceae, ou a estreptomicina e rifampicina nas Pseudomonas spp. Os métodos independentes de cultivo mostram invariavelmente que a maioria das bactérias de uma comunidade são desconhecidas, o que significa que nunca foram cultivadas, caracterizadas e integradas num grupo taxonómico validamente descrito. A taxonomia bacteriana pode ter um importante contributo para gradualmente se reduzir a parcela correspondente às bactérias desconhecidas. Neste estudo o novo nome Bacillus purgationiresistens sp. nov. foi proposto, com base num único isolado recuperado de água tratada. A água de consumo foi confirmada como potencial ponto-chave para a disseminação de bactérias resistentes a antibióticos, com destaque para a transferência ambiente-humanos

Study of bacterial microbiota over the course of tilapia growth cycle in an aquaponics system

Aquaponics combines hydroponic crop production with recirculating aquaculture. These systems comprise various compartments ( in this case: fish tank, biofilter, sump, hydroponic floating raft, settler, and aerobic digester provided by Green in Blue ). Efficient developing of aquaponics in terms of water quality, fish welfare, plant health and food safety requires a thorough understanding of the microbial composition for each compartment of the system . In this study 1m3 dechlorinated tap water aquaponic system stocked with 50 Nile tilapia ( Oreochromisniloticus L., stocked at 5.7 kg per system) and 72 lettuce plants (Lactuca sativa Batavian Red) for 22lettuce cycles of 5 weeks. The experiment was conducted in a small scale, closed-loop, simple recirculating aquaculture system (RAS) running for six months from 18 January ended on 21 July2023. Several physico -chemical water parameters were monitored throughout the cycle to follow the general evolution of the system and correlate potential microbiota variations with water parameters and establish connection to the nitrogen cycle. DNA sequencing results in Figure 1 clearly displays that aquaponics microbiome is complex and each compartment possesses its own bacterial community (p<0.05). An important genus in the biofilter is Nitrospira . This highlights its crucial role in nitrification as no Nitrobacter or Nitrosomonas is detected in the biofilter. Nocardia. A substantial proportion of denitrifying Flavobacterium genus common in soil, aquatic systems and plant-associated habitats were detected in sump. Also, Cetobacterium genus related to fish gut. As conclusion, metagenomics allows optimization of the operational parameters of aquaponics system to prevent pathogen proliferation and pathogen cross transfer among compartments, as well as to enhance efficient functioning of aquaponics biofilters.info:eu-repo/semantics/publishedVersio

Caenimicrobium

Caenimicrobium [Cae.ni.mi.cro'bi.um, L. neut. n. caenum mud, referring to the isolation of the type strain from activated sludge; N.L. neut. n. microbium microbe (from Gr. adj. mikros small and Gr. n. bios life); N.L. neut. n. Caenimicrobium mud (‐inhabiting) microbe]. Proteobacteria / Betaproteobacteria / Burkholderiales / Alcaligenaceae / Caenimicrobium. Gram‐negative‐staining nonmotile short rods, forming beige colonies on nutrient medium. Mesophilic, aerobic, and catalase‐ and cytochrome c oxidase‐positive. Major polar lipids are phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and an unidentified phospholipid, and major cellular fatty acids are C16:1 ω7c, C16:0, cyclo C17:0, and C18:1 ω7c. Ubiquinone 8 is the major respiratory quinone. The type and unique species is Caenimicrobium hargitense, represented by the type strain CGII‐59m2T isolated from activated sludge. Caenimicrobium hargitense strain CGII‐59m2T shares 16S rRNA gene sequence similarity >97% with members of the genera Bordetella, Candidimonas, Paracandidimonas, and Parapusillimonas. DNA G + C content (mol%): 62.3 (HPLC method). Type species: Caenimicrobium hargitense, Felföldi et al. 2017VP.info:eu-repo/semantics/acceptedVersio

Assessment of copper and zinc salts as selectors of antibiotic resistance in Gram-negative bacteria

Some metals are nowadays considered environmental pollutants. Although some, like Cu and Zn, are essential for microorganisms, at high concentrations they can be toxic or exert selective pressures on bacteria. This study aimed to assess the potential of Cu or Zn as selectors of specific bacterial populations thriving in wastewater. Populations of Escherichia coli recovered on metal-free and metal-supplemented culture medium were compared based on antibiotic resistance phenotype and other traits. In addition, the bacterial groups enriched after successive transfers in metal-supplemented culture medium were identified. At a concentration of 1 mM, Zn produced a stronger inhibitory effect than Cu on the culturability of Enterobacteriaceae. It was suggested that Zn selected populations with increased resistance prevalence to sulfamethoxazole or ciprofloxacin. In non-selective culture media, Zn or Cu selected for mono-species populations of ubiquitous Betaproteobacteria and Flavobacteriia, such as Ralstonia pickettii or Elizabethkingia anophelis, yielding multidrug resistance profiles including resistance against carbapenems and third generation cephalosporins, confirming the potential of Cu or Zn as selectors of antibiotic resistant bacteria.info:eu-repo/semantics/publishedVersio

Wastewater reuse in irrigation: A microbiological perspective on implications in soil fertility and human and environmental health

The reuse of treated wastewater, in particular for irrigation, is an increasingly common practice, encouraged by governments and of fi cial entities worldwide. Irrigation with wastewater may have implications at two different levels:alterthephysicochemicalandmicrobiologicalpropertiesofthesoiland/orintroduceandcontributetothe accumulation of chemical and biological contaminants in soil. The fi rst may affect soil productivity and fertility; the second may pose serious risks to the human and environmental health. The sustainable wastewater reuse in agriculture should prevent both typesofeffects,requiring a holisticand integratedrisk assessment. Inthis article wecriticallyreviewpossible effects of irrigation with treatedwastewater, with special emphasison soil microbi- ota. The maintenance of a rich and diversi fi ed autochthonous soil microbiota and the use of treated wastewater with minimal levels of potential soil contaminants are proposed as sine qua non conditions to achieve a sustain- able wastewater reuse for irrigation

Irrigation with Treated Wastewater: Potential Impacts on Microbial Function and Diversity in Agricultural Soils

The reuse of treated wastewater could be a promising measure to attenuate the water scarcity burden. In agriculture, irrigation with wastewater may contribute to improve production yields, reduce the ecological footprint and promote socioeconomic benefits. However, it cannot be considered exempt of adverse consequences in environmental and human health. Apart from the introduction of some biological and chemical hazardous agents, the disturbance of the indigenous soil microbial communities and, thus, of vital soil functions impacting soil fertility may occur. The consequences of these disturbances are still poorly understood. This chapter summarises the physicochemical and microbiological alterations in soil resultant from irrigation with treated wastewater that are described in scientific literature. These alterations, which involve a high complexity of variables (soil, wastewater, climate, vegetal cover), may have impacts on soil quality and productivity. In addition, possible health risks may arise, in particular through the direct or indirect contamination of the food chain with micropollutants, pathogens or antibiotic resistance determinants. The current state of the art suggests that irrigation with treated wastewater may have a multitude of long-term implications on soil productivity and public health. Although further research is needed, it seems evident that the analysis of risks associated with irrigation with treated wastewater must take into account not only the quality of water, but other aspects as diverse as soil microbiota, soil type or the cultivated plant species.info:eu-repo/semantics/publishedVersio

Irrigation with treated wastewater: potential impacts on microbial function and diversity in agricultural soils

The reuse of treated wastewater could be a promising measure to attenuate the water scarcity burden. In agriculture, irrigation with wastewater may contribute to improve production yields, reduce the ecological footprint and promote socioeconomic benefits. However, it cannot be considered exempt of adverse consequences in environmental and human health. Apart from the introduction of some biological and chemical hazardous agents, the disturbance of the indigenous soil microbial communities and, thus, of vital soil functions impacting soil fertility may occur. The consequences of these disturbances are still poorly understood. This chapter summarises the physicochemical and microbiological alterations in soil resultant from irrigation with treated wastewater that are described in scientific literature. These alterations, which involve a high complexity of variables (soil, wastewater, climate, vegetal cover), may have impacts on soil quality and productivity. In addition, possible health risks may arise, in particular through the direct or indirect contamination of the food chain with micropollutants, pathogens or antibiotic resistance determinants. The current state of the art suggests that irrigation with treated wastewater may have a multitude of long-term implications on soil productivity and public health. Although further research is needed, it seems evident that the analysis of risks associated with irrigation with treated wastewater must take into account not only the quality of water, but other aspects as diverse as soil microbiota, soil type or the cultivated plant species.info:eu-repo/semantics/publishedVersio

III Congresso Internacional de Estudantes e Profissionais da Saúde - Menções Honrosas

A 3ª edição do Congresso Internacional de Estudantes e Profissionais da Saúde – DELTA SAÚDE, realizou-se de forma presencial no período de 04 a 06 de novembro de 2022, no Centro de Convenções do Hotel SESC Praia, Luis Correia, Piauí. O Delta Saúde 2022 trouxe como tema geral: “O pós-pandemia e os principais desafios da saúde global”; e as discussões foram norteadas pelos eixos centrais, a saber: a) Pandemia de COVID-19, b) Vigilância em Saúde, c) Saúde Pública e a Atenção Primária, d) Saúde Mental, e) Doenças Crônicas e Doenças Transmissíveis, f) Educação, Formação e Trabalho na Saúde, g) Inovação em Saúde, h) Eixos Transversais. O evento foi criado em 2017 e nesta edição alcançamos pelo menos 10 estados brasileiros em participação direta, palestrantes, convidados, além dos conferencistas internacionais on-line. Esta diversidade aliada a qualidade dos trabalhos apresentados, contribuiu de forma decisiva para o alcance dos objetivos do congresso que primam pela qualificação do ensino na saúde de acadêmicos e pós-graduandos, pelo fortalecimento das práticas profissionais nos serviços de saúde, e pelo incentivo à produção científica. A programação do evento foi composta por palestras nacionais e internacionais, mesas multidisciplinares, cursos livres, seminários, rodas de conversas, encontros e sessões de trabalhos com apresentações nas modalidades: Comunicações Orais e Pôsteres; e com publicação das pesquisas científicas nos Anais do congresso. O evento conto u com 692 inscritos, e destes 42 foram palestrantes que abrilhantaram a programação do congresso. Recebemos 746 resumos para avaliação, e foram apresentados presencialmente 536 trabalhos, sendo 42 premiados com menção honrosa. O evento foi idealizado pela Sociedade Delta Científica e SBCSaúde, teve o apoio do SESC-PI e da Doity, além do apoio científico da FIOCRUZ Piauí, da Editora Pasteur, dos núcleos de pesquisa NUPCelt/UFPI, NAPsiTO/UFPI/UFDPar e NPPM/UFPI; e dos programas de residência multiprofissional RMSFC/UESPI e PRMSF/UFPI/UFDPar. O evento também contou com a parceria de empresas patrocinadoras e expositoras, que tiveram da Comissão Organizadora reciprocidade em suas demandas, a saber: Instituto UniEducacional, WM Saúde e The Nutri Store/PACCO.</jats:p