Effect of NaCl on Heat Resistance, Antibiotic Susceptibility, and Caco-2 Cell Invasion of Salmonella

Table 2

Diameters (mean ± SD; mm) of clear zones formed by S. typhimurium NCCP10812 and S. enteritidis NCCP12243 to single concentrations (0, 2, and 4%) of NaCl and sequentially increased NaCl concentrations up to 4%.

Salmonella strains	Antibiotic	Single concentration of NaCl (%)			Sequential increase of NaCl (%)
		0	2	4	0→0	0→4
S. typhimurium NCCP10812	Amoxycillin	28.0 ± 0.8	27.5 ± 0.6	27.3 ± 0.5	29.0±0.0^A	29.5±0.6^A
	Chloramphenicol	31.8 ± 1.0	33.3 ± 1.5	34.0 ± 1.2	33.3±1.0^A	12.0±2.4^B
	Ciprofloxacin	47.0 ± 1.2	49.5 ± 3.4	48.0 ± 2.3	48.0±1.6^A	46.5±1.9^A
	Gentamicin	26.3 ± 1.0	26.8 ± 1.0	26.8 ± 1.0	26.5±0.6^A	14.3±2.2^B
	Neomycin	22.0 ± 0.8	22.0 ± 0.8	22.3 ± 0.5	24.0±2.2^A	22.3±2.1^A
	Oxytetracycline	26.8 ± 4.9	27.0 ± 4.7	27.0 ± 3.6	30.5±1.7^A	9.5±1.9^B
	Streptomycin	19.0 ± 0.0	19.3 ± 0.5	19.3 ± 1.0	20.3±1.5^A	19.5±1.3^A
	Tigecycline	25.5 ± 1.0	25.8 ± 1.0	26.3 ± 0.5	25.8±0.5^A	26.8±1.5^A
S. enteritidis NCCP12243	Amoxycillin	27.8 ± 0.5	28.0 ± 0.0	26.8 ± 2.2	28.8±1.3^A	21.3±8.4^B
	Chloramphenicol	10.8 ± 2.2	9.8 ± 0.5	11.0 ± 1.6	10.3±2.1^B	30.8±2.8^A
	Ciprofloxacin	44.5 ± 6.4	44.0 ± 4.6	39.3 ± 2.2	43.5±4.1^A	38.0±6.9^B
	Gentamicin	13.3 ± 0.5	13.5 ± 1.3	12.5 ± 0.6	13.8±1.7^B	23.8±5.6^A
	Neomycin	20.5 ± 0.6	21.0 ± 0.0	21.0 ± 0.8	21.0±0.8^A	24.3±2.4^A
	Oxytetracycline	8.0 ± 0.0	8.0 ± 0.0	8.0 ± 0.0	8.0±0.0^B	29.8±1.3^A
	Streptomycin	16.8 ± 0.5	15.0 ± 2.0	15.0 ± 0.8	16.0±0.8^B	25.5±4.8^A
	Tigecycline	25.0 ± 1.2	25.3 ± 1.0	26.8 ± 1.0	26.3±1.0^A	26.8±1.5^A

A-BMeans within the same row with different superscript letters are different (𝑃<0.05).