Covalent loading or directional binding of biomolecules on gold nanoparticles (AuNPs) could lead to
better results than simple direct adsorption for an enhanced ELISA application. The use of Mini-Parasep
solvent-free (SF) without ether or ethyl acetate for the clean and efficient concentration of protozoa
cysts, it is a single-use device for in vitro diagnostic use only. In this work, we used Mini-Parasep SF
for the detection of giardia cysts in comparison to direct smear and Merthiolate-Iodine Formaldehyde
Concentration (MIFC) technique in addition to its use in antigen detection by AuNPs biomolecule
loading using rabbit polyclonal antibodies (pAb) against purified Giardia antigen (PGA). As a result,
Mini-Parasep SF was the most effective method for Giardia cyst detection and regarding optimization of
Mini-Parasep antigen detection, our data showed increased sensitivity and specificity of nano-sandwich
ELISA to 92% and 94% respectively and increased positive predictive value (PPV) and negative
predictive value (NPV) to 88.64% and 95.91% respectively. In conclusion, this research provides that
Mini-Parasep SF concentrator enhanced Giardia cyst detection and improved antigen preparation for
AuNPs sandwich ELISA in giardiasis diagnosis. The advantages of this method are the short assay time
and the raised accuracy of antigen detection providing concentrated samples without the risk of solvent
use and being a disposable Mini-Parasep it helps in giardia antigen purification as well as raising the
sensitivity and specificity of ELISA through binding AuNPs.
Direct microscopic examination of stool specimens is still representing the gold standard in the diagnosis of giardiasis
although it is time-consuming and requires skillful technicians. Multiplex PCR or antigen-based detection
tests show current methods of interest replacing the microscopy in Giardia diagnosis being technically less complex
and requiring limited training1. To reduce diagnostic delays, antigen-based detection diagnostic tests take
a shorter time to give results within 15–20 minutes demonstrating that stool antigen immunodetection-based
modalities are rapid, reliable, sensitive, specific and standardized tests for routine diagnosis of Giardia2.
It was found that comparing antigen-based detection tests to wet mount microscopy and concentration steps
saved time and was suitable for laboratories having little microscopic skills in the scope of diagnosis and not able
to afford the high costive and sophisticated molecular diagnostic methods1.
Mini-Parasep SF fecal concentrator provides a single collection vial to allow the collection and concentration
of stool samples, it was designed to replace the formalin-ether concentration technique and distributed routinely
in laboratories. Due to the high efficacy in detecting parasites, formalin-ether concentration technique is commonly
used in diagnostic purposes and epidemiological studies but it has formalin and ether which carry significant
health hazards for laboratory workers and environmental harms being fiscally detrimental so Mini-Parasep
SF was introduced as a laboratory diagnostic kit in spite of lack of proving its efficacy |
