Detection and identification of Mucorales and Aspergillus in paraffin-embedded samples by real-time quantitative PCR

Background

In this study, we used real-time quantitative PCR (RQ-PCR) to rapidly detect Mucorales and Aspergillus in formalin-fixed, paraffin-embedded (FFPE) samples, targeting 18SrRNA gene and 28SrRNA gene. Identification of Mucorales and Aspergillus was analysed by combining Mucorales RQ-PCR (Mucorales18SrRNA and Mucorales28SrRNA) with Aspergillus RQ-PCR (Aspergillus18SrRNA and Aspergillus28SrRNA).

Objectives

The aims of this study were to compare the diagnostic performances of four RQ-PCR assays as single and combined diagnostic and identification tools.

Methods

We collected 12 control group samples and 81 experimental group samples diagnosed by histopathology, including mucormycosis (19 patients, 21 FFPE samples), aspergillosis (54 patients, 57 FFPE samples) and mucormycosis with aspergillosis (3 patients, 3 FFPE samples). All samples were detected by four RQ-PCR tests to compare and analyze diagnostic performance.

Results

The sensitivities of Mucorales18SrRNA and Mucorales28SrRNA were both 75%, with the tests having specificities of 97.10% and 94.20%. The sensitivities of Aspergillus18SrRNA and Aspergillus28SrRNA were 73.33% and 65%, with the tests having specificities of 87.88% and 81.82%. The values of the evaluation indexes of the combined detection of Mucorales28SrRNA and Aspergillus18SrRNA (M28A18) were the highest with a kappa coefficient value of 0.353, followed by M18A18. M28A18 had a sensitivity of 67.90% and a specificity of 100%.

Conclusions

We recommend using the combination of Mucorales RQ-PCR and Aspergillus RQ-PCR as a screening tool to detect samples suspected of mucormycosis and/or aspergillosis.

Morphological and molecular discrimination of fasciola species isolated from domestic ruminants of urmia city, iran

BACKGROUND

The trematodes of the genus Fasciola (the liver flukes) are among the well-known instances of food-borne parasites worldwide. Differentiation of Fasciola species is important because of their different transmission and epidemiological characteristics. The current study was undertaken to discriminate Fasciola species in the domestic ruminants of Urmia city, Iran.

METHODS

Adult flukes were isolated from the naturally infected livers of the slaughtered water buffaloes and sheep. The flukes were initially identified based on morphological and morphometric parameters. A 618-bp-long fragment of the 28SrRNA gene of Fasciola was amplified by polymerase chain reaction (PCR). The amplified fragment was digested by DraII or AvaII enzymes for a restriction fragment length polymorphism (RFLP) analysis and sequenced for the phylogenetic tree construction.

RESULTS

Based on the morphometric examination, the flukes belonged to F. hepatica, F. gigantica and an intermediate Fasciola form. The PCR-RFLP analysis was able to differentiate F. hepatica from F. gigantica. While the phylogenetic reconstruction justified, to some extent, the morphological diagnosis, it failed to segregate F. hepatica from F. gigantica identified in this and the previous studies.

CONCLUSION

To resolve fully the problem of taxonomy and evolution in Fasciola species, employing a broad range of molecular and morphological approaches is necessary. This is crucial for epidemiological surveys and successful clinical management of their infection.

Detection of Infection with Larval Stages of Ornithobilharzia turkestanicum using PCR in Field-Collected Snails of Lymnaea gedrosiana from Northwestern Iran

BACKGROUND

Infection with Ornithobilharzia turkestanicum has been reported in a wide range of animals worldwide. This study was undertaken to assess the utility of polymerase chain reaction (PCR), for detecting the infection with O. turkestanicum larvae stages in Lymnaea gedrosiana.

METHODS

A total of 6,759 Lymnaeidae snails were collected from six aquatic habitats in West Azarbaijan, northwest Iran. Of these, the snails of L. gedrosiana were identified. To detect infected L. gedrosiana with the larval stages of O. turkestanicum, they were subjected for cercarial shedding and molecular examinations. The genomic DNA was extracted and PCR was performed to specifically amplify a fragment of the nuclear 28SrRNA gene of O. turkestanicum.

RESULTS

Of all collected snails, 5.4% (365/6,759) were the snails of L. gedrosiana. The cercarial shedding method revealed that 23.56% (86/365) of the snails were infected. The PCR patterns confirmed that 28.77% (105/365) snails of L. gedrosiana were infected with larval stages of O. turkestanicum. The infected snails were observed in five studied sites. The highest infection rate (66.66%, 20/30) was recorded in the snails of Ghargologh in the northern part. Only 35.24% (37/105) of the infected snails were from the plain areas, whereas the remaining existed in high altitudes.

CONCLUSION

It was concluded PCR method could be an efficient and fast method for uncovering the actual rate of infection with larval stages of O. turkestanicum in the snails of L. gedrosiana. This method can be also useful for the domestic animals and public health management programs in the country.