Discovery of unique African Helicobacter pylori CagA-multimerization motif in the Dominican Republic

Table 1 Association between the prevalence of cagA and clinical outcomes

	Total	Gastritis	Peptic ulcer	Gastric cancer
Number of strains	120	93	26	1
cagA positive	84 (70.0%)	66 (71.0%)	18 (69.2%)	0
cagA negative	35 (29.2%)	26 (28.0%)	8 (30.8%)	1 (100%)
cagA undetermined	1 (0.008%)	1 (1.1%)	0	0

Table 2 Peptide sequences and types of CagA-multimerization motif in Helicobacter pylori strains

First motif			Second motif			Third motif
Peptide sequences	Type	No.	Peptide sequences	Type	No.	Peptide sequences	Type	No.
FPLKRHDKVDDLSKVG	W-CM	45	FPLKRHDKVDDLSKVG	W-CM	31	FPLKRHDKVDDLSKVG	W-CM	4
FPLKRHDKVEDLSKVG	W-CM	17	FPLRRSAKVEDLSKVG	Af1-CM	21	FPLRRSAKVEDLSKVG	Af1-CM	2
FPLKRHAKVDDLSKVG	W-CM	4	FPLKKHAKVEDLSKVG	D-CM	7	FLLKRHDKVDDLSKVG	W-CM	1
FPLKKHAKVEDLSKVG	D-CM	3	FPLRRSAKVEDLSKAG	Af1-CM	4
FPLKKHDKVDDLSKVG	W-CM	3	FPLKKHDKVEDLSKVG	W-CM	2
FPLKKHDKVEDLSKVG	W-CM	3	FPLKRSAKVEDLSKVG	Af1-CM	2
FPLKKHAKVDDLSKVG	W-CM	2	FPLKRSAKVDDLSKVG	D-CM	2
FLLKRHDKVDNLSKVG	W-CM	1	FPLRRSAKVDDLSKVG	Af1-CM	2
FPLRRSDKVDDLSKVG	D-CM	1	FPLKRYDKVDNLSKVG	W-CM	2
FPLKKHAKVEDLSEVG	D-CM	1	FPLKRHDKVEDLSKVG	W-CM	1
FPLKRHDKIDDLSKVG	W-CM	1	FPLKKHDKVDDLSKVG	W-CM	1
FPLKKHAKVEDLSKAG	D-CM	1	FPLRRSTKVEDLSKAG	Af1-CM	1
Nothing (Deletion)		2	FPLRRSAAVDDLSKVG	E-CM	1
			FPLRRGAKVEDLSKVG	Af1-CM	1
			FPLRKSAKVEDLSKVG	Af1-CM	1
			FPLRRSDKVDNLSKVG	D-CM	1
			FPSKKHAKVEDLSKVG	D-CM	1
			FPFRRSDKVEDLSKVG	Af1-CM	1
			FPLRRSDKVEDLSKVG	Af1-CM	1
Total		84	Total		83	Total		7

The CagA-multimerization (CM) motif types were determined based on comparison with the typical Western CM motif (FPLKRHDKVDDLSKVG), the typical East Asian CM motif (FPLRRSAAVNDLSKVG), and the typical Africa1 CM motif (FPLRRSAKVEDLSKVG). W-CM: Western CM motif; E-CM: East-Asian CM motif; Af1-CM: Africa1-CM motif; D-CM: Different CM motif.

Table 3 CagA-multimerization motif patterns in Helicobacter pylori strains

CM motif pattern	Occurrence	Frequency (%)
W-W	30	35.7
W-Af1	27	32.1
W-D	10	11.9
D-Af1	5	6.0
W-W-W	5	6.0
W-Af1-Af1	2	2.4
-W	2	2.4
D-D	1	1.2
W-E	1	1.2
W-	1	1.2
Total	84

CagA-multimerization (CM) motif patterns were determined based on the identification of CM sequences that were located before and after the (Glu-Pro-Ile-Tyr-Ala)-C motif. W-W: Strains with two Western CM motifs in their CagA; W-Af1: Strains with one Western and one Africa1 CM motif in their CagA; W-D: Strains with one Western and one Different CM motif in their CagA; D-Af1: Strains with one Different and one Africa1 CM motif in their CagA; W-W-W: Strains with three Western CM motifs in their CagA; W-Af1-Af1: Strains with one Western and two Africa1 CM motifs in their CagA; -W: Indicates that only one Western CM motif was observed following the Glu-Pro-Ile-Tyr-Ala (EPIYA)-C motif, in the absence of a CM motif before the EPIYA-C motif; D-D: Strains with two Different CM motifs in their CagA; W-E: Strains with one Western and one East Asian CM motif in their CagA; W-: Indicates that only one Western CM motif was observed before the EPIYA-C motif, in the absence of a CM motif following the EPIYA-C motif.