Conventional techniques (e.g., culture-based method) for bacterial detection typically require a central laboratory and well-trained technicians, which may take several hours or days. However, recent developments within various disciplines of science and engineering have led to a major paradigm shift in how microorganisms can be detected. The analytical sensors which are widely used for medical applications in the literature are being extended for rapid and on-site monitoring of the bacterial pathogens in food, water and the environment. Especially, within the low-resource settings such as low and middle-income countries, due to the advantages of low cost, rapidness and potential for field-testing, their use is indispensable for sustainable development of the regions. Within this context, this paper discusses analytical methods and biosensors which can be used to ensure food safety, water quality and environmental monitoring. In brief, most of our discussion is focused on various rapid sensors including biosensors and microfluidic chips. The analytical performances such as the sensitivity, specificity and usability of these sensors, as well as a brief comparison with the conventional techniques for bacteria detection, form the core part of the discussion. Furthermore, we provide a holistic viewpoint on how future research should focus on exploring the synergy of different sensing technologies by developing an integrated multiplexed, sensitive and accurate sensors that will enable rapid detection for food safety, water and environmental monitoring.

Campylobacter spp. is a major source of global gastrointestinal infections. Their enteric infections are linked to the consumption of undercooked poultry products, contaminated milk and water, and the handling of wild animals and birds. The detection of Campylobacter spp. in water and food samples mainly depends on culture-based techniques. Public Health England (PHE), the U.S. Food and Drug Administration (FDA), and the International Standard Organization (ISO) have standardized Campylobacter spp. isolation and enumeration procedures for food and water samples, which involve the usage of selective agar media and enrichment broth. Different types of selective plating and enrichment media have been prepared for Campylobacter spp. detection and assessment during regular food surveillance and food poisoning. To date, culture media remains the standard option for microbiological food analysis and has been approved by the U.S. Environmental Protection Agency (US EPA), Food and Agriculture Organization (FAO), and World Health Organization (WHO). This review discusses the standard microbiological protocols for Campylobacter spp. isolation and enumeration in food and water and evaluates detection media (pre-enrichment, selective enrichment, and selective plating) for their rational applications. Moreover, it also elaborates on the advantages and disadvantages of recent chromogenic culture media in Campylobacter spp.-oriented food surveillance. This review also highlights the challenges of culture-based techniques, future developments, and alternative methods for Campylobacter spp. detection in food and water samples.

The quality of water used for drinking, irrigation, industrial food processing or for recreational purposes, has a very important impact on human and animal health. So far, 33 surface water localities have been examined in territory of Vojvodina for the presence of 7 different viruses. The prevalence of enteric viruses in the total number of examined localities was up to 60%. These results unequivocally confirm that there is a risk to the health of animals and humans in the area that gravitates to the examined surface water. The risk to public and animal health is particularly significant in areas and localities where the tested surface water are used for agricultural purposes.

Food and water contamination by human viruses is a great health problem. These viruses are shed in stools. Norwalk-like viruses, hepatitis E virus, poliovirus, echovirus, hepatitis A virus, rotavirus, astrovirus, enteric adenovirus and parvovirus B19 have been described. The most important ones are Norwalk-like viruses, rotavirus and hepatitis A virus as reported in epidemiological surveys. The most frequently implicated foods are shellfish (bivalve mollusks) harvested from waters contaminated with human sewage, as well as water itself. The other source of infection is the handling of food in poor hygienic conditions. In this case contaminated foods are vegetables, sandwiches, fruits, pastries that are soiled. The detection of viruses in foods is difficult for several reasons: Virusfood interactions make difficult the concentration and the purification of viruses, several virus species are difficult or unable to grow in cell culture, furthermore viruses are present in the sample in very low amounts. Molecular techniques are therefore the methods of choice for detecting these viruses, especially the polymerase chain reaction which is often described. Another possibility consists in a fecal viral indicator. Bacteriophages seem to be the most promising in this respect.

[ES] La OMS ha declarado que la resistencia a los antimicrobianos es una de las 10 principales amenazas de salud pública a las que se enfrenta la humanidad. La presencia de bacterias resistentes a antibióticos es un problema de salud y seguridad mundial, cada año se identifican cada vez más bacterias resistentes a antibióticos presentes en alimentos, las cuales ofrecen una alta resistencia a los antibióticos de uso común en clínica. Es por ello, que el objetivo de nuestro trabajo pasa por identificar y evaluar la presencia de estas bacterias en distintas muestras de lodos, aguas residuales y aguas de las acequias de agua de riego anexas al Campus de Vera de la Universitat Politècnica de València (UPV). Para llevar a cabo los análisis en primer lugar se hará una determinación de la presencia de patógenos como Salmonella y la calidad higiénico-sanitaria de las aguas y lodos, mediante el recuento de coliformes y E. coli como organismo indicador de contaminación fecal. Seguidamente se procederá a aislar bacterias resistentes a antibióticos en medios selectivos con antibióticos betalactámicos y carbapenémicos y se identificarán mediante pruebas bioquímicos y moleculares en caso de no ser concluyentes los resultados. Posteriormente se realizarán los antibiogramas para evaluar la resistencia fenotípica y se procederá a detectar mediante PCR la presencia de determinados genes de resistencia. | [EN] The World Health Organization (WHO) has proclaimed that antimicrobial resistance constitutes one of the top ten major threats to global public health. The presence of antibiotic-resistant bacteria poses a challenge to global health and security. Each year, an increasing number of antibiotic-resistant bacteria are identified in food, which exhibit a high level of resistance to antibiotics commonly used in clinical practice. In this study, bacterial strains from various sources were investigated, and their resistance to different antibiotic families was analyzed, in addition to exploring the existence of multidrug-resistant strains. Several multiplex PCR assays were conducted to detect resistance genes (to beta-lactam, carbapenem, or quinolone antibiotics) from extracted DNA of isolated strains as well as directly from samples. These assays revealed that samples with the highest prevalence of these genes corresponded to water from irrigation canals adjacent to the campus of Universitat Politècnica de València. Overall, this work highlights the presence of bacteria with antibiotic resistance in agricultural irrigation waters and in sludge used as fertilizers. This finding underscores the need to expand the scope of the research and to enhance the hygienic and sanitary measures implemented during the utilization of the studied sludge and water samples. | Fernandez De Peñaranda Alejandre, A. (2023). Estudio de la presencia de bacterias multi-resistentes en lodos y aguas de uso agrícola de la Comunidad Valenciana en el contexto de la seguridad alimentaria. Universitat Politècnica de València. http://hdl.handle.net/10251/197798