Bacteria isolates from Lake sediments as a promising proxy for temporally tracking organic pollution: A global review

Growing populations, agricultural intensification and inadequate wastewater treatment have led to rising organic pollution in surface water bodies, posing significant public health risks, particularly from waterborne pathogens. Faecal indicator bacteria (FIB) are widely used to monitor water quality and detect organic pollution in water bodies. This systematic review was undertaken to identify and synthesise existing literature on how FIB can be used to track historical changes in organic pollution in lake sediment records and to identify key research gaps. The review summarises prevalent bacterial indicators and existing methods used to analyse how trends in bacterial abundance relate to pollution both spatially and temporally. Beyond bacteria, this review also focuses on the prevalence of antimicrobial resistance (AMR) in sediment records. Overall, key environmental variables affecting bacterial distribution and persistence include organic content, metals and sediment grain size. Particular attention must be given to these variables in future studies for a clear understanding of temporal bacteria distribution in sediment records. The review also highlights the importance of accurately dated sediment cores and historical pollution context to correlate and interpret bacterial distribution patterns over time. Gaps in the literature were observed with only two studies tracking the changes of AMR over time, and many of the existing studies limited to the same lake. The findings of this review emphasize the need for more robust future research across multiple lakes and exploring AMR profiles in sediment cores to understand the evolution of resistance through time.