Table 3.

Interpretation of reactivity with specific probes

ReactionInterpretationComment
d+ onlyH:dH:d from a Salmonella serotype other than Typhi
d+, j+H:dH:d from Salmonella serotype Typhi
j+ onlyH:jH:j from Salmonella serotype Typhi
a+, 1-comp+, 5+Possibly Salmonella serotype Paratyphi ASalmonella serotype Paratyphi A strains have an inactive H:1,5 allele; confirmed by O-group determination
2+, 5-1 weakH:2H:2 and 5 differ by a single nucleotide in the target region; weak cross-reaction (<500) sometimes seen
5-1+, 2 weakH:5H:2 and 5 differ by a single nucleotide in the target region; weak cross-reaction (<500) sometimes seen
x+, z15 weakH:xH:x and z15 differ by a single nucleotide in the target region; weak cross-reaction (<500) sometimes seen
L-comp+ onlyMay be H:l,w, -l,z13, -l,z13,z28, or -l,z40The secondary antigens in these H antigens are not detected in the assay; confirmed by traditional methods
1-comp+ onlyLikely H:1,5The H:5 probe in the assay detects the most-common lineages of H:1,5; confirmed by traditional serotyping
EN-comp+ onlyMay be H:e,n,x,z15H:e,n,x,z15 alleles do not react with the H:x or H:z15 probes; confirmed by traditional serotyping
G-comp+ m/m,t+Likely H:m,tSome H:m,t alleles do not react with the H:t-1 probe, confirmed by traditional serotyping
G-comp+ t-1+Likely H:g,tH:g,t is a very rare antigen; confirmed by traditional serotyping
G-comp+ f+H:f,g or -f,g,tSome H:f,g,t alleles may not react with the H:t-1 probe; confirmed by traditional serotyping
G-comp+ s+Likely H:g,s,tH:g,s,t alleles do not react with the H:t-1 probe, including Salmonella serotype Senftenburg; confirmed by traditional serotyping
Z4-comp+ onlyMay be H:z4z23, -z4,z32, -z4,z23,z32, -z36, -z38, or -z36,z38Only secondary antigen H:z24 is detected in the assay; H:z36 and z38 are genetically related to the Z4 complex and are detected with the Z4-comp probe (24)