DNA diagnostics for reliable and universal identification of Helicobacter pylori

Table 1 Helicobacter pylori positivity by different diagnostic tests

Patients	13C-UBT	Histology (biopsy)	RUT (biopsy)	SAT (stool)	PCR1 (biopsy)	NPCR (biopsy)	NPCR (stool)	NPCR (saliva)
5	+	+	+	+	+	+	+	+
3	+	+	+	+	+	+	+	-
7	+	+	+	+	+	+	-	-
2	+	-	-	+	+	+	+	-
5	+	-	-	+	+	+	-	-
2	+	+	-	-	+	+	-	-
6	+	-	-	-	-	+	-	-
2	+	-	-	-	-	-	-	-
2	-	-	-	-	-	+	-	-
3	-	-	-	-	-	-	-	+
44	-	-	-	-	-	-	-	-
Total 81	32	17	15	22	24	32	10	8

¹Simple polymerase chain reaction (PCR).

Hpup/HPdown primers; 37 cycles; PCR products sequenced. GenBank database comparisons confirmed the DNA sequence origin as Helicobacter pylori. Plus indicates a positive result, minus indicates a negative result[43]. RUT: Rapid urease test; SAT: Stool antigen; PCR: Polymerase chain reaction; NPCR: Nested PCR.

Table 2 Sensitivity and specificity of diagnostic tests

	Histology (biopsy)	RUT (biopsy)	SAT (stool)	PCR (biopsy)	NPCR (biopsy)
Sensitivity (%)	53.1	46.9	68.8	75	100
Specificity (%)	100	100	100	100	95.6
Positive predictive values (%)	100	100	100	100	93.8
Negative predictive values (%)	74.6	72.1	81.5	84.6	91.3

Sensitivity and specificity related urea breath test[43]. RUT: Rapid urease test; SAT: Stool antigen; PCR: Polymerase chain reaction; NPCR: Nested PCR.