Punctual mutations in 23S rRNA gene of clarithromycin-resistant Helicobacter pylori in Colombian populations

Table 1 PCR frequencies of 23S rRNA gene V domain from Helicobacter pylori according to the risk of gastric cancer n (%)

Helicobacter pylori isolates	Risk of gastric cancer		Total
	Low risk-Tumaco	High risk-Túquerres
Evaluated
Susceptible	28 (37.8)	12 (16.2)	40 (54)
Resistant	29 (39.2)	5 (6.8)	34 (46)
Total	57 (77)	17 (23)	74 (100)
Amplified			56 (76)
Susceptible	19 (33.93)	12 (21.43)	31 (55.4)
Resistant	20 (35.7)	5 (8.93)	25 (44.6)
Total	39 (69.6)	17 (30.4)	56 (100)

Table 2 Frequencies of mutations in 23S rRNA gene of Helicobacter pylori according to susceptibility to clarithromycin and risk of gastric cancer n (%)

Susceptibility	Risk of gastric cancer
	Low risk n = 39				High risk n = 17
	Mutant		Non mutant		Mutant		Non mutant
Resistant	13 (23.2)		8 (14.3)		4 (7.1)		1 (1.8)
Susceptible	8 (14.3)		10 (17.8)		6 (10.7)		6 (10.7)
Kappa-P	k = 0.17		P = 0.28		k = 0.23		P = 0.25
Total	21	37.5	18	32.1	10	17.8	7	12.5

Table 3 Punctual mutations in 23S rRNA gene of Helicobacter pylori from the population at low-risk of gastric cancer, according to susceptibility or resistance to clarithromycin

Resistant n = 13			Susceptible n = 8
Patient ID	Mutations	MIC	Patient ID	Mutations	MIC
138	A1593G 1T2183C	1	17	A1822G/G1827A/G1941A/T1831C	< 0.25
64 60	A1653G	2 4	94	T1645C	< 0.25
4	A1739G 1C1954T/G1695A	4	96	A1739G	< 0.25
65	A1739G 1C2196T 1G1827C	1	97	T1645C	< 0.25
42 102 174	A1822G/G1827A/T1831C	1 2 1	98	C1632T	< 0.25
88	C1632T	> 4	101	A1822G/G1827A/T1645C/T1831C	< 0.25
107	1C1770T	1	103	C1632T	< 0.25
38 36	T1645C	1 2	107	A1667G/T1668C	< 0.25
6	1T2183C/A1593T/A1822G/G1827A/T1831C	4
ATCC 700392	A1593G		ATCC 43504	A1667G/T1668C

¹Unique mutations of Helicobacter pylori resistant to clarithromycin. MIC: Minimum inhibitory concentration (μg/mL).

Table 4 Punctual mutations in 23S rRNA gene of Helicobacter pylori from the population at high-risk of gastric cancer, according to susceptibility or resistance to clarithromycin

Resistant n = 4			Susceptible n = 6
Patient ID	Mutations	MIC	Patient ID	Mutations	MIC
323	A1593G/A1822G/G1827A/T1645C/T1831C/1T2183C	1	351	A1822G/G1827A/T1831C	< 0.25
336	A1593G/1C2196T	2	377	A1822G/G1827A/G2221A/T1645C/T1831C	< 0.25
339	1A2144G/G1827A	4	394	A1593G	< 0.25
440	A1822G/G1827A/G2221A/T1831C	4	457	A1822G/G1827A/G2221A/T1831C	< 0.25
			467	A1739G/G1695A	< 0.25
			513	A1822G/G1827A/T1831C	< 0.25
ATCC 700392	A1593G		ATCC 43504	A1667G/T1668C

¹Unique mutations of Helicobacter pylori resistant to clarithromycin. MIC: Minimum inhibitory concentration (μg/mL).

Table 5 Position of mutations according to the domains of 23S rRNA gene of Helicobacter pylori resistant or susceptible to clarithromycin

Domain-Region	Tumaco		Túquerres
	Resistant position	Susceptible position	Resistant position	Susceptible position
Domain IV 1562-1931	C1770T	A1593G		A1593G
	A1593T	A1667G		A1667G
	G1827C	A1739G		A1739G
		A1822G		A1822G
		C1632T		C1632T
		G1695A		G1695A
		G1827A		G1827A
		G1941A		G1941A
		T1645C		T1645C
		T1668C		T1668C
		T1831C		T1831C
Domain V 1932-2541	C1954T	G2221A	C2196T	G2221A
	T2183C		T2183C
	C2196T		A2144G
	A1653G
	C2196T

Table 6 Concordance between mutations in 23S rRNA gene and success or failure of anti-Helicobacter pylori treatment in the studied populations

Breath test[13C]-urea	Population at risk of gastric cancer				Total
	Low risk n = 39		High risk n = 17
	Mutant	No mutant	Mutant	No mutant	Mutant	No mutant
Positive
Therapeutic failure	18	3	8	1	26	4
Negative
Therapeutic Success	3	15	2	6	5	21
Total	21	18	10	7	31	25
Kappa	k = 0.69		k = 0.64		k = 0.71