Sensitivity evaluation of the Gen-Probe AMP-CT assay by pooling urine samples for the screening of Chlamydia trachomatis urogenital infection.
The sensitivity of two urine pool sizes versus individual testing, to detect Chlamydia trachomatis urogenital infection, was evaluated using the Gen-Probe AMP-CT assay. Thirty-three (33) known polymerase chain reaction (PCR) positive urine specimens were combined with 231 fresh first-catch urine (FCU) samples in 33 groups of four and 33 groups of eight, to make up 4X and 8X pooled samples, respectively. Gen-Probe AMP-CT assay was performed on pools as well as on individual samples at the same time. For the discrepant cases, the known positive samples were diluted 1:4 and 1:8 using the manufacturer's dilution buffer and were retested. Additional positive specimens found among fresh FCU samples were also tested by the Amplicor-PCR assay to confirm their positivity. The sensitivities of 8X pooling, 4X pooling and individual testing were 86.5%, 94.3% and 91.9%, respectively. The Gen-Probe AMP-CT assay applied to a 4X urine pooling model was highly sensitive and may be useful for a population based screening programme.
Bacteriology Department, National Institute of Health, Lisbon, Portugal. j.paulo.gomes@insa.min-saude.pt
J P
JP
Gomes
S
S
Viegas
A
A
Paulino
M A
MA
Catry
D002690:Chlamydia Infections / Q000175:diagnosis* / Q000652:urine; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D012680:Sensitivity and Specificity; D014556:Urine / Q000382:microbiology*