Effect of biofilm formation by clinical isolates of Helicobacter pylori on the efflux-mediated resistance to commonly used antibiotics

Table 1 Polymerase chain reaction primers

Primer name	Sequence	Product size, bp
glm-F	5' GGATAAGCTTTTAGGGGTGTTAGGGG 3'	140
glm-R	5' GCATTCACAAACTTATCCCCAATC 3'
16s rRNA-F	5' GAAGATAATGACGGTATCTAAC 3'	139
16s rRNA-R	5' ATTTCACACCTGACTGACTAT 3'
hp1165-F	5' F; TACAACCCCCACGCTAAAAG 3'	117
hp1165-R	5' GGATTTGATGAGCCGAAAAA 3'
hefA-F	5' CTCGCTCGCATGATCGC 3'	162
hefA-R	5' CGTATTCGCTCAAATTCCCT 3'

Table 2 Minimal bactericidal concentration of selected antibiotics in biofilm-forming cells and their planktonic counterparts

Strain	MBC,μg/mL
	AMX		TET		ERY		MTZ
	MBC-P	MBC-B	MBC-P	MBC-B	MBC-P	MBC-B	MBC-P	MBC-B
Hp932	2	8	8	16	4	4	16	32
Hp141	2	4	4	16	2	4	16	32
Hp70	1	4	4	8	2	4	8	16

MBC: Minimal bactericidal concentration; AMX: Amoxicillin; TET: Tetracycline; MTZ: Metronidazole; B: Biofilm-forming; P: Planktonic counterparts.

Table 3 Minimal biofilm inhibitory concentration

Strain	MBIC, μg/mL
	AMX	TET	ERY	MTZ
Hp932	2	2	1	8
Hp141	2	2	1	4
Hp70	1	1	0.5	4

MBIC: Minimal biofilm inhibitory concentration; AMX: Amoxicillin; TET: Tetracycline; MTZ: Metronidazole.