Research

Members of the MARS group have joined efforts for over 25 years sharing research interests in water microbiology related to health. In order to advance together in the improvement of knowledge in this field and to accomplish the main goals of the group in the frame of our research, we propose the following objectives:

 

General objectives

The general objectives are to gather knowledge on the microorganisms transmitted through the faecal-oral route in the environment so as to provide new tools for the improvement of the water management resources with the final aim of preventing the transmission of these diseases. If new diagnostic tools or predictive models susceptible of commercialization are envisaged, we will undertake the corresponding actions. In order to achieve these objectives, the research is organised as follows:

The constant evolution of the genomic methods and the greater knowledge on the intestinal microorganisms, and therefore the appearance of indicators perhaps better than the present ones, make necessary to improve the methodological approaches.

  1. Application of genomic techniques in the study of health-related water Microbiology and detection of pathogens and indicator microorganisms. This area includes three aspects: i) Quantitative application of PCR to detect pathogenic and indicator microorganisms in samples with complex matrices with a lower number of units; ii) metagenomic approaches (DGGE and metagenomic sequencing) for the identification and the detection of some bacteria of difficult or complex culture; iii) detection of indicators (such as bacteriophages) for evaluation of water treatments process based on the ARCPC principles (Analysis of Risk of Critical Points Control).

  2. Availability of specific host strains for the enumeration of bacteriophages. Search of host strains that allow detecting the faecal pollution of those species with greater contribution of pollution in our territory (cows, pig and birds).

  3. Normalization and standardization. MARS participates in international networks to standardize methods.

  4. Prevalence studies. We perform prevalence studies considering: i) pathogens, with special attention to the emergent waterborne pathogens and the indicators in faeces of different origins, raw wastewaters and treated water, surface waters, ground waters, biosolids and food in contact with polluted waters, ii) microorganism indicators of the origin of faecal pollution.

  5. Survival and disinfection. Survival of different pathogens and indicators in the natural environment, and in disinfection processes to predict and to quantify risks, and to use traditional indicators and faecal pollution source indicators in the elaboration of predictive models.

  6. Alternative microbial indicators. Study of the potential utility of alternative indicators (coliphages) to those traditionally used, and the use of genomic techniques to detect pathogens. Both approaches (new indicators and genomic techniques) are applied in the validation and monitoring of wastewater processing, attending above all to advanced processing of new technologies (UV, microfiltration and ultrafiltration, inverse osmosis) and in the processes of sanitation of sewage sludge, that will be necessary its implementation when the new EU regulation come into force.

  7. Molecular epidemiology. The studies of molecular epidemiology are carried out with some of the pathogens, including viruses, of the ones that the prevalence has been studied.

  8. Mechanisms of pathogenicity of water-related and food-borne pathogens of humans and animals.

Interactions of bacteriophages and enteric bacteria. In this area we are working on three main lines:

  1. The first line focuses on importance of phages on the horizontal transfer of genes related to virulence. Within this line our group has extensive experience in the study of Shiga toxin-encoding bacteriophages and other phages harboring virulence genes in pathogenic E. coli. The study of the ecology of these phages and their interaction with the host strain has motivated our studies.

  2. The second line of research is the study of phage particles carrying antibiotic resistance genes. Antibiotic resistance, as one of the most relevant problems for human health worldwide, requires much attention. Among other vehicles of transmission of resistances, our group describes that transduction by means of bacteriophages and phage related particles are one of the less studied and their relevance could be greater as previously considered.

  3. The third line studies the importance of the vast occurrence of phages within the human body biomes and their influence in clinical diagnosis, metagenomic studies or phageomes and their role on the regulation of the populations of bacteria.

Our group belongs to the Spanish network of bacteriophages (FAGOMA) and to the International Society for Viruses of Microorganisms.

The recent metagenomic techniques are applied to the study of the microbial diversity in different aquatic ecosystems, including rivers, wastewater treatment plant, as well as extreme environments such as Antarctica.

Evaluation of the importance of the autoinducers related to quorum sensing systems in selective mechanisms of recognition of bacteria by the intestinal host cells and the potential role of these mechanisms in the settlement of these bacteria.

Improvement of methodologies in the detection of pathogens and alternate microbial indicators.

The constant evolution of the genomic methods and the greater knowledge on the intestinal microorganisms, and therefore the appearance of indicators perhaps better than the present ones, make necessary to improve the methodological approaches.

  1. Application of genomic techniques in the study of health-related water Microbiology and detection of pathogens and indicator microorganisms. This area includes three aspects: i) Quantitative application of PCR to detect pathogenic and indicator microorganisms in samples with complex matrices with a lower number of units; ii) metagenomic approaches (DGGE and metagenomic sequencing) for the identification and the detection of some bacteria of difficult or complex culture; iii) detection of indicators (such as bacteriophages) for evaluation of water treatments process based on the ARCPC principles (Analysis of Risk of Critical Points Control).

  2. Availability of specific host strains for the enumeration of bacteriophages. Search of host strains that allow detecting the faecal pollution of those species with greater contribution of pollution in our territory (cows, pig and birds).

  3. Normalization and standardization. MARS participates in international networks to standardize methods.

  4. Prevalence studies. We perform prevalence studies considering: i) pathogens, with special attention to the emergent waterborne pathogens and the indicators in faeces of different origins, raw wastewaters and treated water, surface waters, ground waters, biosolids and food in contact with polluted waters, ii) microorganism indicators of the origin of faecal pollution.

  5. Survival and disinfection. Survival of different pathogens and indicators in the natural environment, and in disinfection processes to predict and to quantify risks, and to use traditional indicators and faecal pollution source indicators in the elaboration of predictive models.

  6. Alternative microbial indicators. Study of the potential utility of alternative indicators (coliphages) to those traditionally used, and the use of genomic techniques to detect pathogens. Both approaches (new indicators and genomic techniques) are applied in the validation and monitoring of wastewater processing, attending above all to advanced processing of new technologies (UV, microfiltration and ultrafiltration, inverse osmosis) and in the processes of sanitation of sewage sludge, that will be necessary its implementation when the new EU regulation come into force.

  7. Molecular epidemiology. The studies of molecular epidemiology are carried out with some of the pathogens, including viruses, of the ones that the prevalence has been studied.

  8. Mechanisms of pathogenicity of water-related and food-borne pathogens of humans and animals.

Horizontal Gene Transfer. Transduction and bacteriophages.

Interactions of bacteriophages and enteric bacteria. In this area we are working on three main lines:

  1. The first line focuses on importance of phages on the horizontal transfer of genes related to virulence. Within this line our group has extensive experience in the study of Shiga toxin-encoding bacteriophages and other phages harboring virulence genes in pathogenic E. coli. The study of the ecology of these phages and their interaction with the host strain has motivated our studies.

  2. The second line of research is the study of phage particles carrying antibiotic resistance genes. Antibiotic resistance, as one of the most relevant problems for human health worldwide, requires much attention. Among other vehicles of transmission of resistances, our group describes that transduction by means of bacteriophages and phage related particles are one of the less studied and their relevance could be greater as previously considered.

  3. The third line studies the importance of the vast occurrence of phages within the human body biomes and their influence in clinical diagnosis, metagenomic studies or phageomes and their role on the regulation of the populations of bacteria.

Our group belongs to the Spanish network of bacteriophages (FAGOMA) and to the International Society for Viruses of Microorganisms.

Microbial diversity in aquatic ecosystems

The recent metagenomic techniques are applied to the study of the microbial diversity in different aquatic ecosystems, including rivers, wastewater treatment plant, as well as extreme environments such as Antarctica.

Quorum sensing regulated mechanisms.

Evaluation of the importance of the autoinducers related to quorum sensing systems in selective mechanisms of recognition of bacteria by the intestinal host cells and the potential role of these mechanisms in the settlement of these bacteria.