Cholecystolithiasis Is Associated with Clonorchis Figure 5. The egg-positive stones under SEM. a, b, dozens or even hundreds of C. sinensis eggs were visible (original magnification, 6400); c, d, a dozen or even dozens of C. sinensis eggs were adhered to or wrapped with surrounding particles (original magnification, 61000); e, f, muskmelon wrinkles was observed on the surface of the eggs, part of the eggs had depressed surface and particulate matter adhered on the surface and surrounding the eggs (original magnification, 63000). doi:10.1371/journal.pone.0042471.g005 were adhered to or wrapped by bilirubinate granules, mucoid matter and calcium carbonate crystals, which indicate that C. sinensis eggs might be the important nuclear factor involved in the formation of the gallbladder stones, especially pigment gallbladder stones. Coincidentally, results from FTIR spectroscopy analysis showed that the egg-positive stones were mainly pigment stones. However, some researchers have proposed that there is no relationship between C. sinensis infection and cholecystolithiasis PLoS ONE | www.plosone.org 7 August 2012 | Volume 7 | Issue 8 | e42471