First report of human parvovirus 4 detection in Iran.

Parvovirus 4 (PARV4) is an emerging and intriguing virus that currently received many attentions. High prevalence of PARV4 infection in high-risk groups such as HIV infected patients highlights the potential clinical outcomes that this virus might have. Molecular techniques were used to determine both the presence and the genotype of circulating PARV4 on previously collected serum samples from 133 HIV infected patients and 120 healthy blood donors. Nested PCR was applied to assess the presence of PARV4 DNA genome in both groups. PARV4 DNA was detected in 35.3% of HIV infected patients compared to 16.6% healthy donors. To genetically characterize the PARV4 genotype in these groups, positive samples were randomly selected and subjected for sequencing and phylogenetic analysis. All PARV4 sequences were found to be genotype 1 and clustered with the reference sequences of PARV4 genotype 1. J. Med. Virol. 88:1314-1318, 2016. © 2016 Wiley Periodicals, Inc.

Comparison of Parasite Burden Using Real-Time Polymerase Chain Reaction Assay and Limiting Dilution Assay in Leishmania major Infected Mouse.

BACKGROUND: Limiting dilution assay is considered as the gold standard method for quantifying the number of parasites in the animal model of Leishmania infection. Nowadays, real-time PCR is being increasingly applied to quantify infectious agents. In the present study, a real-time PCR assay was developed to estimate parasite burdens in lymph nodes of Leishmania major infected BALB/C mice. Enumeration of parasites was also performed by limiting dilution assay and compared with the results of real-time PCR based quantification. METHODS: The SYBR Green based real-time PCR assay was performed to amplify a 75 bp fragment of superoxide dismutase B1 gene in the lymph nodes of L. major infected BALB/C mice 8 weeks post infection. Mice were infected subcutaneously at the base of their tail with 2 × 10(5) L. major promastigotes in the stationary phase of growth. To compare parasite burdens obtained by real-time PCR assay with those of limiting dilution assay, twelve 8-fold serial dilutions of the lymph node homogenates were prepared in the Schneider medium and incubated at 26°C. After 7 days, wells containing motile parasites were identified by direct observation under an inverted light microscope and the total number of parasites was estimated using the ELIDA software. RESULTS: Spearman's correlation coefficient of the parasite burdens between real-time PCR and limiting dilution assay was 0.72 (P value = 0.008). CONCLUSION: Real-time PCR assay is an appropriate replacement to existing limiting dilution assay in quantifying parasite burden in the experimental model of Leishmania infection.