Among food preservation methods, bacteriophage treatment can be a viable alternative method to overcome the drawbacks of traditional approaches. Bacteriophages are naturally occurring viruses that are highly specific to their hosts and have the capability to lyse bacterial cells, making them useful as biopreservation agents. This study aims to characterize and determine the application of bacteriophage isolated from Indonesian traditional Ready-to-Eat (RTE) food to control Enterotoxigenic Escherichia coli (ETEC) population in various foods. Phage DW-EC isolated from Indonesian traditional RTE food called dawet with ETEC as its host showed a positive result by the formation of plaques (clear zone) in the bacterial host lawn. Transmission electron microscopy (TEM) results also showed that DW-EC can be suspected to belong to the Myoviridae family. Molecular characterization and bioinformatic analysis showed that DW-EC exhibited characteristics as promising biocontrol agents in food samples. Genes related to the lytic cycle, such as lysozyme and tail fiber assembly protein, were annotated. There were also no signs of lysogenic genes among the annotation results. The resulting PHACTS data also indicated that DW-EC was leaning toward being exclusively lytic. DW-EC significantly reduced the ETEC population (P ≤ 0.05) in various food samples after two different incubation times (1 day and 6 days) in chicken meat (80.93%; 87.29%), fish meat (63.78%; 87.89%), cucumber (61.42%; 71.88%), tomato (56.24%; 74.51%), and lettuce (46.88%; 43.38%).

Background: S. Typhi "H58/4.3.1", a single dominant MDRlineage has emerged and spread throughout Asia and Africa over the last 30 years. A large global study speculated South Asia might be the site of original emergence of 4.3.1. Through an ongoing national-wide network of Surveillance of Enteric Fever in India (SEFI), we aim to study the genomic signatures of S. Typhi across different settings. We undertook this study to determine the genotypes of S. Typhi isolated from community (Tier-1) and Hospital (Tier-3) settings in a Southern India region.Methods and materials: A total of 193 and 200 S. Typhi isolated from Tier 1 (Jan-2017 to Sep-2019) and Tier 3 (Nov-2017 to Sep-2019) as part of the network was included. Susceptibility testing was done for most common antimicrobials. At present, whole genome sequencing was done for 30 strains each from Tier-1 and 3. SNP and comparative genomic analysis of Tier 1 and 3 was done to infer difference in the genomic signatures. Geospatial mapping was generated for Tier 1 strains for cluster analysis to infer transmission-dynamic events.Results: Susceptibility rates to first-line agents were highest among community strains with no MDR, whereas 8 MDR strains were isolated from hospital cases. Ciprofloxacin resistance was seen in 5% (9/193) of community isolates compared to the high rates 32% (63/200) among hospital isolates. Notably, genomic analysis showed the dominance of a single H8-lineage 4.3.1.2 (30/30) in community isolates. However, hospital isolates had broader distribution such as 4.3.1.2 (18), 4.3.1.1 (7), 4.3.1.3 (1) and 2.2 and 3.3 respectively. Within the community collection, two sub groups with respect to QRDR profile with S83Y (SG-I) and S83F (SG-II) were found. Interestingly, all SG-II (17/30) appeared to be a single strain with no SNPs differences, being circulated in a defined community setting over 3 months. Conclusion:The baseline data generated here provides multiple insights in terms of a single clade 4.3.1.2 dominating in a community setting, while diverse genotypes seen among typhoid cases attending a tertiary care hospital. However, phylo-geographical analysis of all the isolates would provide a clear picture of the ongoing transmission dynamics between two settings.