Translator Disclaimer
1 September 2014 Survival and Fate of Salmonella enterica serovar Montevideo in Adult Horn Flies (Diptera: Muscidae)
Author Affiliations +

Contamination of cattle peripheral lymph nodes with Salmonella enterica is proposed to occur via a transdermal route of entry. If so, bacteria may be introduced to cattle by biting arthropods. Biting flies, such as horn flies (Haematobia irritans irritans (L.)) (Diptera: Muscidae), are intriguing candidates for transmitting Salmonella to cattle because they provide a route of entry when they breach the skin barrier during blood feeding. Using a green fluorescent protein-expressing strain of Salmonella Montevideo (S. Montevideo-GFP), the current study demonstrated that horn fly grooming subsequent to tactile exposure to the bacteria resulted in acquisition of the bacteria on mouthparts as well as microbial ingestion. Consumption of a bloodmeal containing ≈102, ≈104, or ≈106 S. Montevideo-GFP resulted in horn fly colonization for up to 72 h postingestion (PI). Epifluorescent microscopy indicated that the bacteria were not localized to the crop but were observed within the endoperitrophic space, suggesting that regurgitation is not a primary route of transmission. S. Montevideo-GFP were cultured from excreta of 100% of flies beginning 6–7 h PI of a medium or high dose meal and >12 h PI in excreta from 60% of flies fed the low-dose meal. Animal hides and manure pats are sources for horn flies to acquire the Salmonella and mechanically transmit them to an animal while feeding. Mean quantities of 5.65- 67.5 × 102 CFU per fly were cultured from fly excreta passed within 1 d after feeding, suggesting the excreta can provide an additional microbial source on the animal's hide.

Pia Untalan Olafson, Kimberly H. Lohmeyer, Thomas S. Edrington, and Guy H. Loneragan "Survival and Fate of Salmonella enterica serovar Montevideo in Adult Horn Flies (Diptera: Muscidae)," Journal of Medical Entomology 51(5), 993-1001, (1 September 2014).
Received: 6 November 2013; Accepted: 1 June 2014; Published: 1 September 2014

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top