MOLECULAR EPIDEMIOLOGICAL INVESTIGATION ON CO-INFECTION OF INTESTINAL PROTOZOA IN GASTROINTESTINAL CANCER PATIENTS
Objective The relationship between parasitic infections and cancer has become a research hotpot.Although reports of single intestinal protozoan infection in gastrointestinal cancer patients,co-infections are rare.To investigate co-infections of intestinal protozoa in gastrointestinal cancer patients.Methods The DNA of 195 fecal specimens was amplified using nested PCR and sequenced for the presence of Pentatrichomonas hominis,Giardia duodenalis,Cryptosporidium parvum,Blastocystis hominis,Dientamoeba fragilis,and Enterocytozoon bieneusi.Results An overall infection rate of 48.72%(95/195),with 23 cases(24.21%)co-infected with two parasites,three cases(3.16%)co-infected with three parasites.Additionally,67 cases(70.52%)were infected with one protozoa,including 56 cases with Pentatrichomonas hominis,one with Blastocystis hominis,nine with Cryptosporidium parvum,and one case with Dientamoeba fragilis.No infection with Enterocytozoon bieneusi was detected.Conclusion The results indicated a high rate of intestinal protozoan co-infection among gastrointestinal cancer patients.Through one-way ANOVA analysis,it was observed that cases of individual infection with P.hominis were significantly higher compared to those of co-infection with two or three types of protozoa containing P.hominis(P=0.0022)and cases of co-infection with three types of protozoa(P=0.0019).However,no significant difference in the infection rates was observed between two and three types of protozoa(P=0.2775),suggesting that cases of single infection with P.hominis were higher than cases of co-infection with two or more types of protozoa in gastrointestinal cancer patients.BLAST and single nucleotide polymorphism analysis revealed that gene sequences of different infected protozoa,except for a few with 100%homology to the GenBank reference sequence,exhibited varying degrees of base mutations,insertions,or loss at different loci.This study offers crucial insights for understanding the etiology,diagnosis,and prevention of gastrointestinal cancer.
Gastrointestinal cancer patientsIntestinal protozoanCo-infectedMolecular epidemiology