Table 3. Molecular characterisation of poliovirus SL-3 isolates from airport sewage based on the VP1 sequences, Warsaw, Poland, July 2017–March 2020 (n = 8).

SL-3 isolates	Nucleotide position on VP1 sequence with reference to the complete genome sequence of the reference Sabin 3 strain (AY184221)																	Nucleotide substitutions		VP-1 sequence results
	2493	2636	2665	2762	2806	2905	2975	2989	3028	3178	3184	3228	3248	3283	3305	3335	3338	n	%
Sabin 3	C	G	C	A	C	U	U	C	C	U	U	A	A	C	C	A	A
31 Dec 2018	U	-	-	-	T	C	-	-	-	-	-	-	-	-	-	-	-	3	0.33	SL
15 Jan 2019	U	A	-	-	-	-	-	-	-	-	-	G	G	-	-	-	-	4	0.44	SL
22 Jan 2019	U	A	-	-	-	-	-	-	U	-	-	G	G	-	U	G	-	7	0.78	preVDPV
26 Mar 2019 (36 °C)	U	-	-	-	-	-	-	-	-	C	C	-	-	U	-	-	-	4	0.44	SL
26 Mar 2019 (40 °C)	U	-	-	-	-	-	A	-	-	C	-	-	-	U	-	-	-	4	0.44	SL
4 Jun 2019	U	-	U	-	-	-	-	-	-	-	-	-	-	-	-	-	-	2	0.22	SL
6 Aug2019	U	-	-	-	-	-	-	-	-	-	-	-	G	-	-	-	-	2	0.22	SL
14 Jan2020	U	-	-	G	-	-	-	U	-	-	-	-	-	-	-	-	G	4	0.44	SL

SL: Sabin-like.

Bold letters and grey shading: non-synonymous substitutions. Hyphens: identity with the reference Sabin 3 strain (AY184221).