Bacteroides fragilisCampylobacter lariCampylobacter coliCampylobacter jejuniShellfishHeterophyidaeCampylobacter sputorumCampylobacter upsaliensisArcobacterBacterial Typing TechniquesDNA, BacterialTrematodaMolecular Sequence DataPhylogenySpecies SpecificityTrematode InfectionsBivalviaRNA, Ribosomal, 16SSequence Analysis, DNAPolymerase Chain ReactionFecesDNA, Ribosomal