Serendipitous Isolation of Non-Vibrio Bacterial Strains Carrying the Cholera Toxin Gene from Environmental Waters in Indonesia

Table 2

Tentative taxonomic identity of cholera toxin gene carrying environmental bacterial isolates based on their 16S rRNA gene sequences and biochemical characteristics and distribution of CTX phage encoded genes in each isolate.

Strain No.	Taxonomic Identity by 16S rRNA gene sequence (% identity)*	Taxon phenotypically identified by a commercial kit (API 20E) (% probability of identity)	Results of nested PCR targeting genes; encoded in the CTX phage
			rstR	rstA	rstB	cep	orfU	ace	zot	ctxA	ctxB
GCDV 10-1	Klebsiella variicola; (99%, 1317 bp/1318 bp)	Klebsiella pneumoniae (99.92%)	+	−	−	+	−	+	+	+	+
GCDV 10-2	Pantoea agglomerans; (99%, 1312 bp/1317 bp)	Cirtobacter diversus (60.30%)	−	−	−	−	+	−	+	+	+
GCDV 31-1	Aeromonas caviae; (99%, 1332 bp/1332 bp)	Vibrio fluvialis (99.33%)	−	+	+	+	−	+	+	+	+
GCDV 34-3	Aeromonas veronii; (100%, 1336 bp/1336 bp)	Vibrio alginolyticus (70.67%)	−	−	+	+	+	−	+	+	+
GCDV 47-1	Enterobacter cloacae; (100%, 1322 bp/1322 bp)	Enterobacter cloacae (97.69%)	−	+	+	−	−	−	−	+	+
GCDV 28-2	Enterobacter hormaechei; (100%, 1304 bp/1304 bp)	Enterobacter cloacae (99.42%)	+	+	+	+	+	+	+	+	+
GCDV 37-1	Aeromonas hydrophila; (100%, 1307 bp/1307 bp)	Aeromonas hydrophila group (99.95%)	+	−	+	+	+	−	+	+	+
GCDV 50-6	Vibrio parahaemolyticus; (99%, 1321 bp/1323 bp)	Aeromonas salmonicida (50.43%)	−	−	+	+	+	−	+	+	+
Vibrio cholerae N16961 (positive control)	Not determined	Not determined	+	+	+	+	+	+	+	+	+

∗Taxa with >98% sequence identities its nearest type strain as determined by comparison of the partial 16S rRNA gene sequence (approx. 1300 bp) of CRIB with sequences present in the database using the BLAST tool from NCBI.