Evaluation of Omphisa fuscidentalis Larvae as a Virulence Model Injected with Bacteria from Healthy Individuals and Hospitalized Patients

Background and Aim: One of the animal models for bacterial virulence testing is Omphisa (O.) fuscidentalis.The purpose of this study was to evaluate O. fuscidentalis larvae as an animal model for bacterial virulence testing in healthy individuals and hospitalized patients. Materials and Methods:The design of this study was experimental.Bacterial samples were obtained from Mitra Keluarga Hospital, Bekasi, Indonesia.Molecular identification of bacteria was confirmed using partial 16S rRNA gene sequencing.Identification and susceptibility testing of bacteria was performed using Vitek 2 compact.The dose treatment of bacterial isolates Staphylococcus (S.) haemolyticus, Enterococcus (E.) faecalis, and Klebsiella (K.) pneumoniae (10 3 , 10 4 , 10 5 ) was carried out on survivability of O. fuscidentalis larvae over 24 hr post-injection.Giemsa staining was used to find hemocytes in the hemolymph of O. fuscidentalis.Hemocytes were also evaluated through microscopic observation.Results: Klebsiella pneumoniae strains were resistant to more than five classes of antibiotics.The lowest survival percentage was obtained in O. fuscidentalis larvae injected with K. pneumoniae.Microscopic observation of dead O. fuscidentalis larvae showed hemocytes from melanized larvae exhibited swelling. Conclusion:Although this research is still basic, O. fuscidentalis larvae showed to be a probable promising alternative model to assess bacterial virulence.However, comparative studies with established test animals are needed.