@phdthesis{Preusser2024, author = {Preußer, Daniel}, title = {Effects of the antibiotics ceftriaxone and levofloxacin on the growth of forensically relevant blow flies (Diptera, Fam. Calliphoridae) and effects on the determination of the post-mortem interval}, doi = {10.26127/BTUOpen-6893}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-68936}, school = {BTU Cottbus - Senftenberg}, year = {2024}, abstract = {Forensic entomology is a subfield of entomology in which the time of death is determined based on the species composition and age of the maggots found. Entomotoxicology combines forensic entomology and toxicology by investigating the effects of toxic substances on forensic relevant species. Ceftriaxone is a cephalosporin and belongs to the β-lactam antibiotics and levofloxacin is a quinolone antibiotic. Because of endogenous bactericidal secretions, maggots are adapted to live on surfaces with a high density of potential bacterial pathogens such as corpses, carcasses, excrements, or other decaying materials. This property is utilised in medicine to treat bacterial infections and in forensic sciences to determine the time of death and raises the question of the extent to which an additional bactericidal source influences the development of maggots. To answer this question experiments were carried out for three different species in the family Calliphoridae (blow flies). The species Lucilia sericata, Calliphora vomitoria and Protophormia terraenovae were selected for the study to remain within one family of Diptera. For each test procedure, 8 samples were prepared. A control treatment without antibiotics, one treatment each with a ceftriaxone concentration of 28.57 μg/g, 14.3 μg/g and 7.14 μg/g, one treatment each with a levofloxacin concentration of 3.57 μg/g, 1.79 μg/g and 0.89 μg/g and a mixed treatment. Additional tests were conducted in the microbiology department of the Medizinische Universit{\"a}t Lausitz - Carl-Thiem to test the duration of the effects of antibiotics in the culture medium. Both antibiotics are significantly longer active in the nutritional basis without natural elimination. The antibacterial effects of levofloxacin were observed at all examined concentrations during all 10 days of the tests and antibacterial effects of ceftriaxone were observed for 6, 7 and 8 days respectively. The maggot development of Calliphora vomitoria was significantly delayed by 24 - 48 hours depending on the concentration of the antibiotics, which could result in an underestimation of the post-mortem interval. The maggot development of Lucilia sericata was not significantly altered by the used antibiotics, errors in the determination of the time of death are therefore unlikely. Depending on the concentration of the antibiotics, the development time of Protophormia terraenovae was significantly reduced by 24 - 48 hours. The reduced development time could result in an overestimation of the post-mortem interval. As Protophormia terraenovae is considered to be a medically utilised species, the improved growth conditions could be relevant for both forensic investigations and medical treatments. The significantly different effects of the tested antibiotics on the three species highlight that it is impossible to draw conclusions and generalise about effects on other untested species.}, subject = {Entomotoxicology; Entomotoxikologie; Antibiotika; Schmeißfliegen; Entomologie; Leichenliegezeit; Antibiotics; Blowflies; Entomology; Post-mortem interval; Schmeißfliegen ; medizinische Entomologie; Ceftriaxon; Levofloxacin; Todeszeitbestimmung}, language = {en} }