Competence of the housefly, Musca domestica, as a vector of Microsporum canis under experimental conditions

Abstract

The role of Musca domestica Linnaeus as a vector of the dermatophyte Microsporum canis was investigated under experimental laboratory conditions. About 400 4-day-old M. domestica flies were divided into two groups. Group A consisted of about 200 infected flies and group B comprised about 200 uninfected flies that were used as controls. Each trial was run three times. Flies from group A were fed for 24 h with a solution of ultra-high temperature-treated (UHT) milk containing about 10(6) colony-forming units (CFU) per mL of M. canis (infected milk inoculum [IMI]). The control group (group B) was fed with only UHT milk spiked with a teaspoon of honey. Microsporum canis was detected from faeces, vomitus, external surfaces and internal organs of 20 adult flies, eggs, first-, second- and third-stage (L1, L2, L3) larvae and pupae of each group, as well from 20 adult newly emerged flies (NEFs; from infected generations only). Samples were collected at 2, 4, 6 and 24 h post-infection (p.i.) (i.e. the times at which IMI was available) and on 2, 5, 7 and 8 days p.i. from adult flies, faeces and vomitus. Eggs, L1, L2, L3 and pupae were processed as soon as they appeared. Equivalent samples were taken from group B. All the samples were individually cultured. Microsporum canis was not isolated from the control group, from eggs, larvae, pupae or NEFs, or from faeces and vomitus, although it was detected on the body surface (26.2%) and internal organs (26.9%) of adult flies. The highest positivity for M. canis was detected on flies within the first 6 h p.i. (i.e. 57.2% on the body surface and 71.6% in the internal organs). No M. canis was isolated at 24 h p.i., but it was isolated from the body surface only at 2 and 5 days p.i. The results presented provide evidence that M. domestica transmits M. canis mechanically with its outer body surface for up to 5 days p.i., but does not do so through its vomitus and faeces or transovarially. The role played by M. domestica in the epidemiology of human and animal dermatophytoses is discussed.

Phenotypic variation of the housefly,Musca domestica: amounts and patterns of wing shape asymmetry in wild populations and laboratory colonies

“…It is synanthropic and a public health threat because both adults and saprophagous larvae feed on feces, vomitus and decaying animal and vegetable matter. As a vector of a range variety of viral, bacterial and other pathogens (over 100 according to Sanchez-Arroyo, 2008), the housefly has an important role in disease transmission to humans and animals (Grübel et al , 1998; Sehgal et al , 2002; Cafarchia et al , 2009; Barin et al , 2010; Wanaratana et al , 2011). Pathogens living inside and/or on its body surface can be transmitted through mouth secretions, mechanically and through feces (Cafarchia et al , 2009) causing serious diseases such as cholera, typhoid fever, bacillary dysentery, tuberculosis, anthrax ophthalmia, amebiais and poliomyelitis (Greenberg, 1970, 1973; Sanchez-Arroyo, 2008).…”

The potential of house flies to act as a vector of avian influenza subtype H5N1 under experimental conditions

“…(Greenberg, 1973), Salmonella spp. (Holt et al , 2007), Escherichia coli (De Jesus et al , 2004), Vibrio cholerae (Yap et al , 2008), Newcastle disease virus (NDV) (Watson et al , 2007), turkey coronavirus (Calibeo‐Hayes et al , 2003), porcine reproductive and respiratory syndrome virus (Otake et al , 2003), rotavirus (Tan et al , 1997), Microsporum canis (Cafarchia et al , 2009) and metazoan parasites (Förster et al , 2007). House flies transmit pathogens via mouthparts, vomit droplets, faeces and their body surface (Greenberg, 1973).…”

Fungi Isolated From House Flies (Diptera: Muscidae) on Penned Cattle in South Texas

“…It may be that our fly collections, although sampled from cattle with ringworm lesions, were less than optimal in terms of contagion. Indeed, canine ringworm ( M. canis ) was detected on the surface of experimentally inoculated house flies up to 5 d after introduction (Cafarchia et al 2009), indicating that collections at timepoints after the peak of the inoculum may be suboptimal for culturing the fungus.…”