Searching for a more sensitive and accurate
marker for schistosomiasis diagnosis and treatment follow
up is a potential necessity. Hereby, we evaluated usefulness
of circulating free DNA as a marker for schistosomiasis
diagnosis, assessing drug efficacy and monitoring the
control interventions impact using SYBR green real-time
PCR. A batch of mice were infected by 90 ± 10 Schistosoma
mansoni cercariae. Starting from the 2nd day post
infection (p.i.), groups of 2 or 3 mice were sacrificed every
3 days until 30 days p.i. The remaining animals were
treated by a single dose of 400 mg/kg mefloquine and
sacrificed in group at 5, 10, 21 days post treatment (35, 40,
51 days p.i.). Using SYBR green real time qPCR, pooled
sera DNA were extracted and amplified. The results
showed that, circulating free S. mansoni DNA was detected
from the 2nd day post infection (p.i.) onwards with gradual
decrease in the cycle threshold value Ct which indicates the
gradual elevation of the DNA level (Log quantity was
2.6–3.1 IU/ml), As the infection progressed, DNA quantity
was increased(Log quantity was 6.29 IU/ml). Initial
increase of circulating free DNA was observed 10 days
post treatment (40 days p.i.) (Log quantity was 7.38 IU/
ml). That was followed by a progressive decrease in DNA
level by the end of 21st day, post treatment (51 p.i.) (Log
quantity 4.35 IU/ml). In conclusion, circulating free S.
mansoni DNA is a reliable marker in the diagnosis of
schistosomiasis and for assessing drug efficacy and monitoring the impact of control interventions. |
