Peri-urban aquacultures produce nutritious food in proximity to markets, but poor surface water quality in rapidly expanding megacities threatens their success in emerging economies. Our study compared, for a wide range of parameters, water quality downstream of Bangkok with aquaculture regulations and standards. For parameters not meeting those requirements, we sought to establish whether aquaculture practice or external factors were responsible. We applied conventional and advanced methods, including micropollutant analysis, genetic markers, and 16S rRNA amplicon sequencing, to investigate three family-owned aquacultures spanning extensive, semi-intensive and intensive practices. Canals draining the city of Bangkok did not meet quality standards for water to be used in aquaculture, and were sources for faecal coliforms, Bacteriodes, Prevotella, Human E. coli, tetracycline resistance genes, and nitrogen into the aquaculture ponds. Because of these inputs, aquacultures suffered algae blooms, with and without fertilizer and feed addition to the ponds. The aquacultures were sources of salinity and the herbicide diuron into the canals. Diuron was detectable in shrimp, but not at a level of concern to human health. Given the extent and nature of pollution, peri-urban water policy should prioritize charging for urban wastewater treatment over water fees for small-scale agricultural users. The extensive aquaculture attenuated per year an estimated twenty population equivalents of nitrogen pollution and trillions of faecal coliform bacteria inputs from the canal. Extensive aquacultures could thus contribute to peri-urban blue-green infrastructures providing ecosystem services to the urban population such as flood risk management, food production and water pollution attenuation.

A re-evaluation of the taxonomic position of five strains, one assigned to Cronobacter sakazakii (strain 1330T, isolated from spiced meat purchased in Slovakia), two previously assigned to Cronobacter genomospecies 1 (strains NCTC 9529T and 731, isolated from water and a leg infection, respectively) and two previously assigned to Cronobacter turicensis (strains 96 and 1435, isolated from onion powder and rye flour, respectively) was carried out. The analysis included phenotypic characterization, 16S rRNA gene sequencing and multilocus sequence analysis (MLSA) of seven housekeeping genes (atpD, fusA, glnS, gltB, gyrB, infB, ppsA; 3036 bp). 16S rRNA gene sequence analysis and MLSA showed that strain 1330T formed an independent phylogenetic lineage in the MLSA, with Cronobacter dublinensis LMG 23823T as the closest neighbour. DNA–DNA reassociation and phenotypic analysis revealed that strain 1330T represented a novel species, for which the name Cronobacter condimenti sp. nov. is proposed (type strain 1330T = CECT 7863T = LMG 26250T). Strains NCTC 9529T, 731, 96 and 1435 clustered together within an independent phylogenetic lineage, with C. turicensis LMG 23827T as the closest neighbour in the MLSA. DNA–DNA reassociation and phenotypic analysis confirmed that these strains represent a novel species, for which the name Cronobacter universalis sp. nov. is proposed (type strain NCTC 9529T = CECT 7864T = LMG 26249T).