Assessing the prevalence of FRNA bacteriophages and their correlation with SARS-CoV-2 RNA in the wastewater of Mumbai city

Bacteriophages have been explored as indicators of the presence of human viruses in water. F+ coliphages are of particular interest due to their abundance in wastewater and some groups surviving the treatment process. This study assessed the prevalence of F+ coliphages and FRNA bacteriophage (FRNAPH) groups in the wastewaters of Mumbai city and explored its correlation with the presence of SARS-CoV-2. Wastewater samples (raw = 63, treated = 99) collected from three wastewater treatment plants (WWTPs) were assessed for F+ coliphages, FRNAPH groups and SARS-CoV-2. Of the 63 raw wastewater samples, 92% were positive for F+ coliphages and FRNAPH, while SARS-CoV-2 was detected in 76% of samples; FRNAPH GI RNA was the most prevalent (96.82%) followed by FRNAPH GII (77.77%), FRNAPH GIII (36.50%), and FRNAPH GIV (4.76%). A significant correlation was observed between the occurrence of SARS-CoV-2 and F+ coliphages, FRNAPH GII and FRNAPH GIII RNA copies and also between F+ coliphages and FRNAPH GII and GIII. These observations suggest that F+ coliphages, FRNAPH GII and GIII can be explored further as indicators of SARS-CoV-2 in wastewaters. Also, F+ coliphage detection may be a cost-effective and practical approach for monitoring virus elimination during wastewater treatment.