MOLECULAR CHARACTERIZATION AND GASTROINTESTINAL TRACT ECOLOGY OF COMMENSAL HUMAN FOOD-BORNE BACTERIAL PATHOGENS IN THE CHICKEN
Location: Poultry Microbiological Safety Research
Title: Darkling Beetles as a Potential Transmission Source of Salmonella in Broiler Flocks
Submitted to: Feedinfo News Service
Publication Type: Trade Journal
Publication Acceptance Date: May 4, 2008
Publication Date: May 24, 2008
Citation: Fairchild, D.B., Roche, A.J., Hinkle, N.C., Cox Jr, N.A., Richardson, L.J., Buhr, R.J., Cason Jr, J.A. 2008. Darkling Beetles as a Potential Transmission Source of Salmonella in Broiler Flocks. Feedinfo News Service. P.18.
Interpretive Summary: The genera Salmonella is an important human pathogen. The adult and larval darkling beetles (Alphitobius diaperinus Panzer) are common insect pests of commercial broiler operations. High populations of darkling beetles in commercial broiler operations can have a negative impact financially due to structural and insulation damage within the house, reduced feed efficiency and increased pest control expenses. In this report, information is provided on the role of darkling beetles as a means for transmission of Salmonella within a broiler flock.
The adult and larval darkling beetles (Alphitobius diaperinus Panzer) are common insect pests of commercial broiler operations. High populations of darkling beetles in commercial broiler operations can have a negative impact finanacially due to structural and insulation damage within the house, reduced feed efficiency and increased pest control expenses. Darkling beetles have also been shown to serve as biological vectors for a number of bacterial and viral diseases that include but are not limited to Marek's Disease, Runting and Stunting, Infectious Bursal Disease, Fowl Pox, and Newcastle Disease. The objective of the current report was to review findings on darkling Beetles as a potential transmission source of Salmonella in broiler flocks. Beetles, either adult or larval were inoculated by feed with Salmonella and then orally gavaged into a subset of broilers which served as seeder birds. The seeder birds were placed into pens containing broielrs and the spread of the inoculated strain of Salmonella was observed over the 6 week grow-out. Stepped-on drag swabs were collected weekly to evaluate the spread of the marker S. Typhimurium in the litter. At 3 wk-of-age, the seeder birds and 10 non-challenged birds were euthanized and their ceca sampled to evaluate spread across birds. At 6 wk-of-age the ceca from all the remaining (non-challenged) birds in each pen were also sampled. From drag swabs, 3 of 4 pens containing larval beetle-challenged chicks remained positive for the 6 wk study, and the fourth pen was positive for the marker for up to 3 wk. One of the adult beetle challenged pens remained positive for the 6 wk duration of the study, 2 remained positive for 5 wk after challenge, and the final pen was positive for 4 wk. The marker S. Typhimurium was maintained in the litter of the control pens for up to 6 wk in 1 pen, 5 wk in 2 pens, and 4 wk in 1 pen. From the ceca samples, 57% of the adult beetle-challenged birds and the pen mates were positive for the marker and continued to excrete S. Typhimurium for 3 to 6 wk. In the chicks that were challenged with larval beetles, 25% were positive for S. Typhimurium and 29% of the pen mates were positive. These data demonstrate that darkling beetles can be a source of S. Typhimurium colonization of day-old broiler chicks.