Table 2.

Plaque size distribution and differential count (pfu/ml) of five different groups of isolated coliphages

Site	Point of sample collection	Coliphages isolated against	Count (pfu/ml) of five different groups of coliphages according to their plaque size
		E. coli strain	<1 mm	1–2 mm	2–3 mm	3–5 mm
DMCH Sewage	Excreta kept here for 24 h	EHEC	5	0	0	0
		EIEC	45	20	25	0
		EPEC	15	75	30	0
		ETEC	105	145	40	0
		E. coli K-12	240	210	100	35
	Excreta dumping site (excreta dumped here for 15 days)	Proper bacterial lawn formation failed so that enumeration of coliphages was not possible
	Sewage outlet	EHEC	35	0	0	0
		EIEC	55	130	0	0
		EPEC	75	116	34	0
		ETEC	195	131	149	0
		E. coli K-12	90	335	175	75
Treatment plant, Pagla	Influent sewer	EHEC	52	33	0	0
		EIEC	40	0	0	0
		EPEC	41	54	0	0
		ETEC	40	0	0	0
		E. coli K-12	60	0	0	0
	Primary sedimentation tank	EHEC	0	30	10	0
		EIEC	5	0	0	0
		EPEC	5	0	0	0
		ETEC	5	0	5	0
		E. coli K-12	26	0	0	0
Sewage	Facultative lagoon	EHEC	0	0	0	0
		EIEC	0	0	0	0
		EPEC	0	0	0	0
		ETEC	0	0	0	0
		E. coli K-12	0	0	0	0