Listeria species: Reemerging pathogen in drinking water utilities

Abstract

Listeria monocytogenes is recognized worldwide as one of the most important foodborne pathogens of concern for the food industries. It is a ubiquitous microorganism, and it is commonly isolated from foods of animal origin, mainly meat and milk products, but a few Listeria outbreaks have occurred in which these pathogens have been isolated from water systems and implicated as source of infection. The bacteria are aerobic and facultative anaerobic and non-spore and non-capsule forming, with optimal growth temperature of between 30 °C and 37 °C. They can, however, grow and reproduce at temperatures between 0.4 °C and 45 °C and pH 4.5–9.6. In the present chapter, occurrence of Listeria spp. in ground, surface, and bottled drinking water along with survival of Listeria spp. in oligotrophic and copiotrophic environments and antibiotic susceptibility, molecular detection, pathogenicity, and virulence of Listeria spp. have been discussed in detail. Listeria monocytogenes cause listeriosis, abortion, human meningitis, infection during the perinatal period, granulomatosis infantiseptica, sepsis, diarrhea, pyelitis, and “flu-like” symptoms. The mortality rate of listeriosis is ~30 %. It is a major concern for food and water microbiologists. There are currently no suitable microbiological criteria in India for the detection of emerging pathogens. There is need to revaluate the effectiveness of traditional indicators for risk management due to the emergence of pathogens. This confirmed the need for development of better microbial monitoring for assessing the safety of drinking water.