Tag Archives: fly

I’m known as the flyslayer around the home: More debate on the role of houseflies in E. coli transmission

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The ecology of Escherichia coli O157:H7 is not well understood. The aims of this study were to determine the prevalence of and characterize E. coli O157:H7 associated with houseflies (HF).

 Musca domestica L. HF (n = 3,440) were collected from two sites on a cattle farm over a 4-month period and processed individually for E. coli O157:H7 isolation and quantification. The prevalence of E. coli O157:H7 was 2.9 and 1.4% in HF collected from feed bunks and a cattle feed storage shed, respectively. E. coli O157:H7 counts ranged from 3.0 × 101 to 1.5 × 105 CFU among the positive HF. PCR analysis of the E. coli O157:H7 isolates revealed that 90.4, 99.2, 99.2, and 100% of them (n = 125) possessed the stx1, stx2, eaeA, and fliC genes, respectively.

Large populations of HF on cattle farms may play a role in the dissemination of E. coli O157:H7 among animals and to the surrounding environment.

Association of Escherichia coli O157:H7 with houseflies on a cattle farm

July 2018

Applied and Environmental Microbiology vol. 84 no. 14

Muhammad Alam and Ludek Zurek

doi: 10.1128/AEM.70.12.7578-7580.2004

http://aem.asm.org/content/70/12/7578?ijkey=717a5417861fddb53638f51da6eecec048234a81&keytype2=tf_ipsecsha

Watching flies: Sex may influence house fly transmission of pathogens

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Salmonella Typhimurium is a pathogen that causes gastroenteritis in humans and can be harbored by house flies. Factors influencing excretion of S.Typhimurium from infected flies have not been elucidated but are essential for assessing transmission potential.

We determined the persistence and excretion of a green fluorescent protein (GFP) expressing strain of S. Typhimurium from house flies. Individual male and female flies were fed either sterile Luria-Bertani (LB) broth (controls) or cultures of “high” (~105colony forming units [CFU]) or “low” (~104 CFU) doses of bacteria (treatments). Bacterial persistence was determined over 16 h by culturing whole-fly homogenate. Both sex and dose affected persistence between 6 and 12 h post-ingestion.

In a separate experiment, fly excretion events were monitored during this time interval and excreta droplets were individually cultured for bacteria. Female flies had more excretion events than males across treatments. We observed interactions of fly sex and bacterial abundance (dose), both on the proportion of Salmonella-positive droplets and the CFU shed per droplet (CFU/droplet). In the low-dose treatment, males excreted a greater proportion of positive droplets than females. In the high-dose treatment, males excreted more CFU/droplet than females. High-dose male flies excreted more CFU/droplet than low-dose males, but low-dose females excreted more CFU/droplet than high-dose females. Irrespective of sex, low-dose flies excreted a greater dose-adjusted CFU (CFU droplet/CFU fed) than high-dose flies.

This study demonstrates that both bacterial abundance and fly sex may influence excretion of bacteria from flies, and should be considered when assessing the risk of house fly transmission of pathogens.

Effects of bacterial dose and fly sex on persistence and excretion of Salmonella enterica serovar Typhimurium from adult house flies

11 April 2018

Journal of Medial Entomology

Dana Nayduch Klara Zurek Jessica L Thomson Kathleen M Yeater

https://doi.org/10.1093/jme/tjy055

https://academic.oup.com/jme/advance-article/doi/10.1093/jme/tjy055/4967820

My daughter calls me flyslayer: I can’t stand flies, but are they a food service risk?

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For decades, various food safety-types have debated the role of flies in the transmission of disease in food service settings, and more importantly, the significance.

Now that we live in an old distinguished house in Brisbane, and in every other place we’ve lived close to downtown (CBD) we know screens are an afterthought.

And maybe I’m an OK cook, because every time I start slicing and dicing, the flies converge, if the windows are open.

So we got central air installed – Brisbane breezes be damned – and keep the windows closed, yet I still go about my daily slaughter of about 50 flies.

Researchers at Penn State Eberly College of Science have found house flies carry salmonella, E. coli and even bacteria, which can lead to stomach ulcers and fatal sepsis.

The research, published in Scientific Reports, says flies may have been overlooked by public health officials as a source of disease outbreaks.

The paper found that flies legs transferred most of the microbial organisms from one surface to another, suggesting even a brief step onto food could leave behind bacteria.

Flies in urban areas were found to carry more bacteria than rural flies, with the scientists suggesting to avoid city parks for picnics and, instead, eating food in more rural locations.

The study suggests flies pick up the bacteria from faeces and decaying organic matter, which they use to nurture their young.

”People had some notion that there were pathogens that were carried by flies, but had no idea of the extent to which this is true and the extent to which they are transferred.” said Dr Donald Bryant, Professor of Biotechnology at Penn State University.

“We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials.”

Flyslayer: Flies transport Campylobacter in the kitchen

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I hate flies.

As a kid I would occupy myself for hours in my grandfather’s barn, swatting to death as many flies as I could. Sure it was futile, and a good indicator of life-long neuroses, but I sure like killing them.

fly.slayer.may.16Many of the houses in Brisbane don’t have screens. We paid extra to have screens installed in our new townhome. But the neurotic cats have to hang out on the balcony so the screens sometimes stay open and flies swoop in to soil my lovingly prepared meals.

My daughter calls me Flyslayer.

My partner bought me this battery-charged, tennis-racquet sized flyswatter so I can zap flies mid-flight.

Here’s why:

The house fly, Musca domestica, has been implicated as a vector of Campylobacter spp., a major cause of human disease. Little is known whether house flies serve as biological amplifying hosts or mechanical vectors for the.flyCampylobacter jejuni.

We investigated the period after C. jejuni had been ingested by house flies in which viable C. jejuni colonies could be isolated from whole bodies, the vomitus and the excreta of adult M. domestica and evaluated the activation of innate immune responses of house flies to ingested C. jejuni over time. C. jejuni could be cultured from infected houseflies soon after ingestion but no countable C. jejuni colonies were observed > 24 hours post-ingestion. We detected viable C. jejuni in house fly vomitus and excreta up to 4 hours after ingestion, but no viable bacteria were detected ≥ 8 hours. Suppression subtractive hybridization identified pathogen-induced gene expression in the intestinal tracts of adult house flies 4-24 hours after ingesting C. jejuni. We measured the expression of immune regulatory (thor, JNK, and spheroide) and effector (cecropin, diptericin, attacin, defensin and lysozyme) genes in C. jejuni-infected and -uninfected house flies using quantitative real time PCR. Some house fly factor, or combination of factors, eliminates C. jejuni within 24 hours post-ingestion.

Because C. jejuni is not amplified within the body of the housefly, this insect likely serves as a mechanical vector rather than as a true biological, amplifying vector for C. jejuni, and adds to our understanding of insect-pathogen interactions. 

Campylobacter jejuni in Musca domestica: An examination of survival and transmission potential in light of the innate immune responses of the house flies

Insect Science. doi: 10.1111/1744-7917.12353.

Gill, S. Bahrndorff, and C. Lowenberger

http://www.ncbi.nlm.nih.gov/pubmed/27134186

Flies as a source of dangerous bacteria

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Around the house, I’m known as the fly slayer, because in Brisbane at this time of year, we leave our balconies open.

FlyBut I can’t stand flies in my kitchen.

The mechanical transmission of pathogenic bacteria by synanthropic filth flies is widely recognized. While many studies report the fate and the temporospatial distribution of ingested foodborne bacteria by filth flies, there is little evidence about the transmission dynamics of ingested foodborne bacteria by adult house flies (Musca domestica) to their progeny.

In this study, we fed parental house fly adults with food contaminated with low, medium, and high concentrations of Salmonella enterica, Cronobacter sakazakii, Escherichia coli O157:H7, and Listeria monocytogenes and evaluated the probability of transmission of these pathogens to house fly eggs and the surface and the alimentary canal of their first filial (F 1 ) generation adults.

Results: All foodborne pathogens were present in samples containing pooled house fly eggs. The probability of transmission was higher after parental house flies ingested food containing medium bacterial loads.

Cronobacter sakazakii was 16, 6, and 3 times more likely to be transmitted to house fly eggs than S. enterica, E. coli O157:H7, and L. monocytogenes, respectively.

Only S. enterica and C. sakazakii were transmitted to F 1 generation adults and their presence was 2.4 times more likely on their body surfaces than in their alimentary canals. The highest probabilities of finding S. enterica (60Â %) and C. sakazakii (28Â %) on newly emerged F 1 adults were observed after parental house flies ingested food containing medium and high levels of these pathogens, respectively.

Conclusion: Our study demonstrates that adult house flies that fed from food contaminated with various levels of foodborne bacteria were able to transmit those pathogens to their eggs and some were further transmitted to newly emerged F 1 generation adults, enhancing the vector potential of these insects.

Understanding the type of associations that synanthropic filth flies establish with foodborne pathogens will help to elucidate transmission mechanisms and possible ways to mitigate the spread of foodborne pathogens.

Ingested Salmonella enterica, Cronobacter sakazakii, Escherichia coli O157:H7, and Listeria monocytogenes: transmission dynamics from adult house flies to their eggs and first filial (F 1 ) generation adults

7th Space Interactive, BMC Microbiology 2015

Monica Pava-Ripoll Rachel Pearson Amy Miller Ben Tall Christine Keys George Ziobro

http://7thspace.com/headlines/514122/ingested_salmonella_enterica_cronobacter_sakazakii_escherichia_coli_o157h7_and_listeria_monocytogenes_transmission_dynamics_from_adult_house_flies_to_their_eggs_and_first_filial_f___________________1_generation_adults.html

Beijing sets ‘two-fly’ rule for public restrooms

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Fox News reports that public restrooms in Beijing must contain no more than two flies per stall, according to a bizarre new directive issued to washroom attendants.

The Beijing Municipal Commission of City Administration and Environment issued the rule Monday as a "new standard for public toilet management," the Beijing News reported.

Xie Guomin, the official in charge of the initiative, told the newspaper that the two-fly rule was not compulsory, but was a new benchmark to improve the Chinese capital’s notoriously unpleasant public restrooms.

"We will not actually count fly numbers. The regulation is specific and quantified, but the inspection methodology will be flexible."

Sentencing next for fish bar operator who sickened 5 with E. coli

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A U.K. court was told yesterday that Wrexham librarian Karen Morrisroe (right, exactly as shown) spent three months in hospital – where she also picked up the hospital superbug, MRSA – and had been psychologically damaged as a result of E. coli O157 after eating a veggie burger and chips from the Llay Fish Bar in 2009.

Anthony Vines, prosecuting, told the court there were five primary cases of E. coli which could be linked to the takeaway, although there were secondary infections.

Council officers found pizza toppings at the takeaway covered in flies, a lack of handwashing materials and clothes in handbasins which were also put over frozen doner kebabs, and inadequate training.

Karen Morrisroe said her illness had resulted in “unbearable stomach pains,” being severely dehydrated, suffering kidney failure and a small seizure. Other victims included an 11-month-old baby, two three-year-old girls and a five-year-old child.?

??Mr Justice Griffith-Williams said he would sentence Ramazan Aslan, former operator of the Llay Fish Bar, next week after reading all background reports. But in granting him bail, he told him that he should not interpret that as meaning there would not be a prison sentence.