Vector potential of houseflies (Musca domestica) for Helicobacter pylori

Abstract

The mode of transmission of Helicobacter pylori is unknown. Since viable bacteria have been shown to be excreted in feces from infected individuals and houseflies habitually develop and feed on excrement, we hypothesized that flies ingest and harbor H. pylori and, in turn, contaminate the human environment. This study examined the possible vector potential of houseflies (Musca domestica) for H. pylori. Caged houseflies were exposed to freshly grown H. pylori on agar plates. After a 6-h feeding period, the plates were removed and were replaced with sterile petri dishes containing a droplet of sterile brucella broth. At regular intervals, small numbers of houseflies were removed for microbiological and histological analysis, and the petri dishes were replaced with fresh sterile plates with fresh drops of brucella broth. The flies' bodies, the flies' dissected alimentary tracts, and excreta on the petri dishes were cultured for H. pylori, whose identity was confirmed by the urease, catalase, and oxidase reactions and Gram staining. In contrast to control flies, viable H. pylori could be isolated from external surfaces for up to 12 h and from gut and excreta for as long as 30 h after the initial feeding period. After 30 h other gram-negative bacteria overgrew the cultures of samples from all locations tested, rendering the selective culture of H. pylori colonies impossible. Histological analysis revealed Helicobacter-like organisms in the gut lumen and attached to intestinal epithelial cells. We conclude that houseflies can harbor viable H. pylori on their bodies and in their intestinal tracts. They are also able to disseminate viable H. pylori in excreta, and they may therefore present a significant reservoir and be a vector in the transmission of H. pylori.

The Incidence ofHelicobacter pyloriAcquisition in Children of a Canadian First Nations Community and the Potential for Parent‐to‐Child Transmission

“…Although the transmission of H. pylori by houseflies that feed on excrement has been postulated, our negative PCR results in the flies as well as raspberry samples obtained also reinforce the theory of interpersonal spread [26]. Crowded living conditions and inadequate sanitary conditions that have been associated with H. pylori seropositivity in nonaboriginal populations [50 -52] have also been shown to facilitate interpersonal spread of other enteric organisms in North American Indian and Inuit communities in Canada [2,53,54].…”

Pediatric Issues Workshop Summary

“…The epidemiology of H. pylori infection was considered, particularly the postulated environmental reservoirs such as domestic cats, houseflies, and water [5][6][7][8][9][10][11]. The potential modes of transmission (fecal-oral, oral-oral) were then presented [12][13][14].…”

“…A review of the history of H. pylori infection in children and the first published articles from pediatric investigators were described. The first articles by investigators appeared in the literature within 6 months of each other describing the infection and its association with clinical disease in children [1][2][3][4].The epidemiology of H. pylori infection was considered, particularly the postulated environmental reservoirs such as domestic cats, houseflies, and water [5][6][7][8][9][10][11]. The potential modes of transmission (fecal-oral, oral-oral) were then presented [12][13][14].…”

Characterization of anHelicobacter pylorienvironmental strain

“…The natural habitat for the micro-organism is the human stomach, but it may also survive in other environments to become a life-long infection threat (Sasaki et al 1999). Helicobacter pylori has been detected in dental plaque, in human and animal faeces (Grubel et al 1997;Parsonnet et al 1999;Kabir 2003), and a large number of studies report its presence in aquatic environments (Adams et al 2003;Cellini et al 2004Cellini et al , 2005aBraganca et al 2007). Water supplies contaminated by sewage containing fluids or faeces from infected people have therefore been considered as a potential source of H. pylori transmission (Mazari-Hiriart et al 2001;Park et al 2001;Lu et al 2002;Cellini et al 2004;Ahmed et al 2007).…”