A systematic review of human pathogens carried by the housefly (Musca domestica L.).

BACKGROUND: The synanthropic house fly, Musca domestica (Diptera: Muscidae), is a mechanical vector of pathogens (bacteria, fungi, viruses, and parasites), some of which cause serious diseases in humans and domestic animals. In the present study, a systematic review was done on the types and prevalence of human pathogens carried by the house fly. METHODS: Major health-related electronic databases including PubMed, PubMed Central, Google Scholar, and Science Direct were searched (Last update 31/11/2017) for relevant literature on pathogens that have been isolated from the house fly. RESULTS: Of the 1718 titles produced by bibliographic search, 99 were included in the review. Among the titles included, 69, 15, 3, 4, 1 and 7 described bacterial, fungi, bacteria+fungi, parasites, parasite+bacteria, and viral pathogens, respectively. Most of the house flies were captured in/around human habitation and animal farms. Pathogens were frequently isolated from body surfaces of the flies. Over 130 pathogens, predominantly bacteria (including some serious and life-threatening species) were identified from the house flies. Numerous publications also reported antimicrobial resistant bacteria and fungi isolated from house flies. CONCLUSIONS: This review showed that house flies carry a large number of pathogens which can cause serious infections in humans and animals. More studies are needed to identify new pathogens carried by the house fly.

Livestock-associated MRSA survival on house flies (Musca domestica) and stable flies (Stomoxys calcitrans) after removal from a Danish pig farm.

We caught stable- and house flies on a Danish LA-MRSA positive pig farm. Stable- and house flies were housed together and culled over time to test for the presence of live LA-MRSA bacteria at 24 h intervals to establish the length of time for which LA-MRSA can persist on flies. On average, 7% of stable flies and 27% of house flies tested positive for LA-MRSA immediately upon removal from the farm. LA-MRSA prevalence decreased over time and estimates based on a Kaplan-Meier time-to-event analysis indicated that the probability of a stable- or house fly testing positive for LA-MRSA was 5.4% and 7.8% after 24 h, 3.5% and 4.3% after 48 h, 3.1% and 2.2% after 72 h and 0.4% and 0% after 96 h of removal from the pig farm, respectively. Simultaneously, we found that caged cultivated house flies became carriers of LA-MRSA, without direct contact with pigs, in the same proportions as wild flies inside the farm. We provide distance distributions of Danish pig farms and residential addresses as well as the calculated maximum dispersal potentials of stable- and house flies, which suggest that there is a potential for stable- and house flies dispersing live LA-MRSA bacteria into the surrounding environment of a pig farm. This potential should therefore be considered when modelling the spread between farms or the risk posed to humans living in close proximity to LA-MRSA pig farm sources.

Towards an odour-baited trap to control Musca sorbens, the putative vector of trachoma.

Musca sorbens is a synanthropic filth fly that aggressively attacks people to feed from mucous membranes of the eyes, nose or mouth, from open sores, or from sweat. It has long been suspected that this fly contributes to the transmission of eye infections, particularly trachoma, and recent work has added to the evidence base that M. sorbens is a trachoma vector in Ethiopia. There are few options to control M. sorbens, largely due to a lack of evidence. Space spraying with insecticides is effective, but an environmentally sound and long-term sustainable solution would be better, for example, mass trapping. We tested commercially available and homemade trap types in a pilot (laboratory) study and three field studies. A homemade design, built from a bucket and two empty water bottles, baited with a commercially available lure, The Buzz, was found to be most effective. This trap caught 3848 M. sorbens over 26 trap 'events' (3- or 4-day periods); mean/median per 24 h 43.6 (standard deviation 137.10)/2.25 (IQR 0.25-12.67). The Buzz lure is cheap and effective for 4 weeks, and trap components cheap and locally available. Further studies are needed to understand the impact of this trap on local fly populations and the local transmission of trachoma.

First record of human myiasis caused by association of the species Chrysomya megacephala (Diptera: Calliplioridae), Sarcophaga (Liopygia) ruficornis (Diptera: Sarcophagidae), and Musca domestica (Diptera: Muscidae).

We report a rare case of myiasis caused simultaneously by three dipterous species. A 54 yr-old indigent patient was admitted to Andaraí Hospital with painful eruptions on the scalp. The parieto-occipital sulcus showed two lesions caused by scratching associated with deep, odoriferous and exudative pediculosis. Larvae removed with the help of forceps and vaseline produced 153 adults, identified in the laboratory as 114 specimens of Chrysomya megacephala (F., 1794), 38 of Sarcophaga (Liopygia) ruficornis (F., 1794), and one of Musca domestica (L., 1758).

Laboratory Rearing of Stable Flies and Other Muscoid Diptera.

Stable flies, Stomoxys calcitrans, are serious pests of livestock, humans, companion animals and wildlife worldwide. During the last 20+ years, changes in agronomic practices resulted in serious outbreaks of stable flies in several countries. These outbreaks disrupted livestock production and human recreation resulting in public demands for increasing research and management efforts for this pest. A simple and inexpensive procedure for rearing stable flies for laboratory studies is presented. The procedure uses locally available diet components, equipment and supplies. The procedure can be adapted for rearing other muscoid flies including face fly (Musca autumnalis), horn fly (Haematobia irritans), and house fly (Musca domestica). The procedure produces stable fly puparia averaging 12.5 mg and ~35% egg to adult survival. Approximately 3000 flies are produced in each pan.

Susceptibility of Musca domestica larvae and adults to entomopathogenic nematodes (Rhabditida: Heterorhabditidae, Steinernematidae) native to Mexico.

We evaluated the pathogenicity of the entomopathogenic nematodes native to Mexico, Heterorhabditis indica, Heterorhabditis sp. and Steinernema sp., towards M. domestica under controlled conditions. For adults, concentrations of 1,600 (A) and 1,200 (B) nematodes/ml were considered. For larvae, only the first concentration applied to filter paper, wheat bran, and peat moss as substrates was evaluated. An analysis of variance showed that the differences in adult mortality were only significant (p = 0.0001) among nematode species but not among concentrations within species. However, differences were significant (p = 0.0001) when data were analyzed when 50% of the individuals died (LT50 ). For H. indica, the LT50 were 46.5 h and 65.8 h for the concentrations A and B, respectively. Females were more susceptible than males. H. indica recorded the highest mortality, with 79.2% and 35.5% for females and males, respectively. Significant differences (p ≤ 0.05) were recorded in larval mortality. H. indica induced the highest mortality (53.3%) when applied on peat moss. The results are a fundamental basis for future management studies of M. domestica by entomopathogenic nematodes.

Purification of pimplin, a paralytic heterodimeric polypeptide from venom of the parasitoid wasp Pimpla hypochondriaca, and cloning of the cDNA encoding one of the subunits.

We have previously detected a paralytic factor in gel filtration-separated venom from the endoparasitoid wasp Pimpla hypochondriaca which is active against the fly Musca domestica. Now we have further purified this factor, which we have called pimplin, by reverse phase chromatography, and established using SDS-PAGE that it has a molecular mass of approximately 22 kDa. A 40 ng dose of pimplin administered to adult M. domestica by intrahaemocoelic injection was sufficient to kill all flies tested. Treatment of pimplin with beta-mercaptoethanol prior to SDS-PAGE analysis resulted in the appearance of two polypeptides of approximately 15 and 6 kDa, indicating that pimplin is a heterodimer whose polypeptides are linked through a disulphide bond. Subunit masses of 10.544 and 6.318 kDa were determined using MALDI-TOF analysis indicating that the larger subunit migrates anomalously in SDS-PAGE. Using an oligonucleotide probe designed from N-terminal sequence obtained for the 15 kDa polypeptide, we have isolated a cDNA (pim1) encoding this larger pimplin subunit. The N-terminal amino acid sequence of pim1 occurred 28 residues beyond a predicted signal peptide cleavage site, indicating that pim1 is synthesised as a pre-propolypeptide which is secreted and proteolytically cleaved to yield the mature polypeptide stored in the venom sac. Beginning at the fourth residue of the mature pim1 venom polypeptide is a stretch of 46 residues consisting of alternating prolines, the significance of which is discussed in terms of possible host processing.

Bases moleculares da absorção de nutrientes, tamponamento e fluxos de fluídos no intestino médio de Musca domestica / Molecular bases of nutrient absorption, buffering and fluid fluxes in the midgut of Musca domestica

O intestino dos insetos representa uma interface pouco protegida dos agentes externos. A identificação dos mecanismos moleculares envolvidos nos processos fisiológico-digestivos permite encontrar alvos potenciais para o controle de insetos. As moléculas envolvidas na absorção de nutrientes, tamponamento e geração de fluxos de água no intestino médio do inseto-modelo Musca domestica (Diptera Cyclorrhapha) foram identificadas. Para isso, foi feita uma análise da expressão gênica ao longo do intestino médio, a identificação e anotação de proteínas por bioinformática, a confirmação da localização apical das proteínas por análise proteômica de membranas microvilares purificadas e a determinação do papel de algumas das proteínas através de experimentos in vivo utilizando diferentes dietas, corantes e inibidores. A acidificação da região média é consequência da atividade anidrase carbônica que gera prótons que são bombeados por uma H+ V-ATPase apical acompanhados por cloreto transportado por um simporter K+Cl-. O K+ é recuperado por um canal de K+ e a homeostase dos cátions mantida pela Na+/K+-ATPase basolateral. O bicarbonato é eliminado basolateralmente em troca por cloreto por um antiporter. A acidificação é regulada diretamente por um antiporter Na+/H+ e indiretamente por uma proteína envolvida na homeostase do cobre. O muco protetor da região média é tamponado com bicarbonato gerado por uma anidrase carbônica com âncora de GPI e transportado por um antiporter Na+HCO3-/H+Cl-. O excesso de ácido é eliminado por um antiporter Na+/H+ situado na membrana basolateral. A alcalinização da região posterior ocorre pelo transporte apical de NH3 que sequestra os prótons luminais gerando amônio, junto à remoção de prótons em simporte com aminoácidos e peptídeos. A acidificação intracelular, consequência da entrada de aminoácidos com prótons, é regulada por uma H+ V-ATPase basolateral. A geração de fluxos de água é consequência da atividade conjunta de simporters NKCC e KCC ajudados pelas aquaporinas. A inibição dos simporters com inibidores específicos mostrou que o contrafluxo de água está envolvido na reciclagem da enzima tripsina. Por último, o principal lugar de absorção nutrientes no intestino médio é a região posterior, a exceção do cobre que é absorvido na região média

The gut of insects is a less protected interphase against external agents. The identification of the molecular mechanisms involved in physiological-digestive processes allows one to find potential targets for insect control. The molecules involved in nutrient absorption, buffering and fluid fluxes in the midgut of the insect-model M. domestica (Diptera Cyclorrhapha) were identified. For this, gene expression along the midgut was analyzed; proteins were identified and annotated by bioinformatics; apical localization of proteins was confirmed by proteomics of purified microvillar membranes; the role of proteins was confirmed by in vivo experiments using different diets, dyes and inhibitors. Middle midgut acidification occurs by the action of an apical H+ V-ATPase with protons coming from carbonic anhydrase activity accompanied by chloride transported with potassium by a K+Cl- symporter. Potassium is recovered by a potassium channel, and cation homeostasis maintained by a basolateral Na+/K+-ATPase. Acidification is directly regulated by a Na+/H+ antiporter and indirectly by a copper homeostasis protein. Mucus protecting epithelium is neutralized with bicarbonate generated by a GPI-ancored carbonic anhydrase and transported by a Na+HCO3-/H+Cl- antiporter. Intracellular acidification is avoided by a basolateral Na+/H+ antiporter. Posterior midgut alkalization occurs by the action of an apical ammonia transporter and proton amino acid (and peptide) symporters. Intracellular acid is eliminated by a basolateral H+ V-ATPase. Fluid fluxes are generated by K+Cl- and Na+Cl-Cl- symporters helped by aquaporins. Inhibition of these symporters showed that the countercurrent flux of water allows trypsin recycling. Finally, posterior midgut is the main location of nutrient absorption, except for copper which is absorbed in the middle midgut

Oral myiasis: a case report.

Oral myiasis is a rare condition caused by the invasion of tissues by larvae of flies. A case of gingival myiasis is presented in a 12-year-old boy with learning disability. The patient was unaware of the lesion, although it produced a swelling partially covering the teeth. The lesion was treated with ether, which forced the larvae out, and irrigated with warm saline solution. Follow-up examination revealed complete subsidence and healing of the lesion.

Aislamiento de enterobacterias en la mosca común (Musca domestica) en Coro, estado Falcón, Venezuela / Isolation of enterobacteria from Musca domestica in Coro, Falcon state, Venezuela

La mosca común (Musca domestica) es una especie con una amplia ubicuidad adaptada a los ambientes humanos, y que constituye un problema de salud pública en aquellas áreas rurales y urbanas con un inadecuado manejo sanitario. En un intento por aislar enterobacterias en adultos de M. domestica, entre Enero y Mayo de 2006 se han recolectado, mediante mallas entomológicas ad hoc, 30 ejemplares en tres sitios de la ciudad de Coro, estado Falcón, Venezuela: mercado municipal (N=10), Hospital Universitario “Alfredo Van Grieken” (HUAVG) (N=10) y basurero municipal (N=10). El análisis bacteriológico reveló la presencia en el 96,67% de las moscas sembradas de seis géneros y diez especies de bacterias Gram negativas de la familia Enterobacteriaceae, incluyendo: Enterobacter cloacae, E. gergoviae, E. aerogenes, Escherichia coli, Pantoea agglomerans, Proteus mirabilis, P. vulgaris, Providencia rettgeri, P. alcalifaciens y Morganella morganii. De éstas, se aislaron siete especies de enterobacterias en las moscas capturadas en los alrededores del HUAVG, y seis en el mercado y el basurero municipales. P. agglomerans (30%: 9/30), P. mirabilis (23,33%: 7/30) y E. cloacae (16,67%: 5/30) fueron las especies bacterianas más frecuentemente aisladas. Como las especies de Enterobacteriaceae detectadas en el presente trabajo en M. domestica también han sido aisladas en infecciones dérmicas, urinarias, pulmonares y gastrointestinales de humanos del HUAVG, se sugiere por lo tanto que la mosca común pudiera estar jugando un papel importante como forente en la transmisión de bacterias potencialmente patógenas para el hombre en ambientes hospitalarios, domiciliarios y establecimientos de ventas de alimentos (mercados) de la ciudad de Coro, estado Falcón, Venezuela.

The housefly (Musca domestica) is a species and is characteristically associated with human activity. Houseflies constitute a health hazard in rural and urban areas with poor sanitary facilities. Between January and May 2006, enterobacteria were isolated in 30 adults of Musca domestica captured in 3 municipal environments: an out market (N=10), a dumping ground (N=10) and a hospital (HUAVG) (N=10), from Coro city, Falcón state, Venezuela. Bacteriological analysis revealed the presence of 10 Gram negative bacterial species (Enterobacteriaceae) in 96.67% of the flies cultured, including: Enterobacter cloacae, E. gergoviae, E. aerogenes, Escherichia coli, Pantoea agglomerans, Proteus mirabilis, P. vulgaris, Providencia rettgeri, P. alcalifaciens y Morganella morganii. Of these, seven enterobacteria species were isolated from flies collected in HUAVG, and six each from those caught in market and dumping ground areas. Pantoea agglomerans (30%: 9/30), P. mirabilis (23.33%: 7/30) and E. cloacae (16.67%: 5/30) were the enterobacteria most frequently detected. The Enterobacteriaceae specie isolated here from M. domestica also has been detected in human dermal, urinary, pulmonary and gastrointestinal infections at HUAVG. Therefore, the role of the housefly as a potential mechanical vector of potentially pathogenic enterobacteria to humans in hospital, domiciliary and food supply environments from Coro city, Falcón state, Venezuela, is suggested.

Presencia de Haematobia irritans (L)(Diptera:Muscidae) en ganado lechero estabulado de Aguascalientes, México: Informe preliminar / Precence of Haematobia irritans (L) (Diptera:Muscidae) in confined dairy cattle in Aguascalientes, Mexico: preliminary report

Con el objetivo de detectar la presencia de la mosca hematófaga Haematobia irritans en ganado bovino de la región lechera del estado de Aguascalientes, México, fueron seleccionados al azar 60 establos, los cuales se visitaron una vez por mes durante el periodo de mayo a julio de 1997; los establos mantienen al ganado, de raza Holstein, en confinamiento bajo el sistema de estabulación libre. En cada visita se eligieron al azar 10 vacas en producción, se sujetaron y con una trampa entomológica se colectaron moscas del dorso, costado y frente de las piernas, los especímenes se trasladaron al laboratorio para su posterior identificación taxonómica. Se encontró a Haematobia irritans en la totalidad de los establos y en el periodo de estudio; además se colectaron sobre el cuerpo de los animales ejemplares de Stomoxys calcitrans, Musca domestica, Fannia canicularis y Muscina stabulans. La presencia de Haematobia irritans en ganado lechero estabulado en una región semiárida es un hallazgo importante, aunado al hecho de que convive con Stomoxys calcitrans, especie hematófaga común en los establos. Se concluye que Haematobia irritans se encuentra presente y ampliamente distribuida parasitando al ganado bovino lechero estabulado de Aguascalientes