Journal of Food: Microbiology, Safety & Hygiene
Open Access

The Effect of Natural Falling and Dipping of House Fly (Musca domestica) on the Microbial Contamination of Water and Milk

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Introduction

House flies may carry non-pathogenic or pathogenic microorganisms and may also possess and transfer many antimicrobial factors that act against many of these microorganisms in addition to many enzymes that can affect the pathogenic microorganisms. As we previously discussed, studies of the microorganisms on the wings of the house fly, as well as the effect of dipping the house flies in any edible liquid for human consumption, such as milk or water, must be conducted as we preceded in this area [1]. Recently, a study was demonstrated on the molecular levels by Sudong, et al. to pinpoint the nature and structure of some antimicrobial factors within house fly known as Antimicrobial Peptides (AMPs), which has a significant role of such molecular diversity in the housefly antimicrobial immune systems [2].

According to Food and Drug Administration (FDA), house flies and other pests may transport about 25% of foodborne infections which are reported annually such as Enterohemorrhagic colitis, shigellosis, salmonellosis, and cholera.

House flies may acquire food borne microorganisms from the residues of infected persons such as vomitus, stools, and body. On the other hand, house fly disseminated microorganisms through; direct contact, faeces, and mouth secretions [1,3].

In the present article, we are aiming to summarize our previous findings of the effect of dipping the house fly in consumable liquids and the existence of antimicrobial factors in the house fly.

Materials and Methods

Samples collection

Samples of house fly (Musca domestica) were collected from Jeddah and Makkah and were directly transferred to the laboratory to compare between the natural falling and dipping of house fly in water and milk. Each house fly was packed in sterile test tubes [4].

Natural falling and dipping experiments in water

The sterile tubes containing the house flies were opened oppositely to larger sterile test tubes containing 10 ml sterile water and started dropping one by one of the house flies. The tubes were left for 20 seconds before culturing on different microbial media. The experiments were applied in two different methods; the first method was by using the same house flies in the natural falling and dipping treatments, and the second method was by using different house flies in each treatment of dipping and natural falling. The dipping treatments were also divided into two methods; the first method was by one complete dip for the flies for 20 seconds, and the second method was by three times complete dipping for 20 seconds in water. The microbial load of the contaminated water was determined directly after falling or dipping by incubation of 15, 30, 45 and 60 minutes at room temperature on nutrient agar to determine the total microbial flora. Non-haemolytic and haemolytic flora were determined on blood agar. The experiments were applied in neutral sterile tap water and sterile water at pH 4.0.

Natural falling and dipping experiments in milk

Another series of natural falling and dipping experiments of house flies were carried out on sterile milk and the microbial load was determined after incubation at room temperature for 3 hours.

Results and Discussion

Natural falling and dipping in water

The obtained data showed in Table 1 which declared the comparison between natural falling and dipping once and triple for 60 minutes. The results evident showed that natural falling resulted in higher contamination than dipping. Thus, when the fly was tested by dipping it will carry less amount of microbial flora. This may explain the higher counts observed in natural falling treatments. On the other hand, as presented in Table 2, the results declared that after dipping or falling in sterile water for separated house flies in each treatment, the triple dipping treatment gave lower counts in microbial load than those reported for natural falling and once dipping samples [5]. This indicates the remarkable effect of dipping when compared to natural falling as the house fly was washed in the surface water from most of the microorganisms and antimicrobial factors in the natural falling treatment, and still showed lower microbial counts after the dipping treatments. Also, the incubations time at room temperature before culturing was shown to be effective as the long period of incubation allows the reaction between microorganisms and microbial factors to happen and subsequently the reduction of the microbial count. Furthermore, the once and triple dipping in sterile water at pH 4.0 showed generally lower counts than the natural falling treatments, which indicates that the antimicrobial factors were still effective at pH 4.0.

Table 1: Effect of natural falling and dipping of house fly in sterile water on counts of total bacterial flora, non-haemolytic and haemolytic microorganisms (mean of five replicates-counts/ml) [1].

Table 2: Effect of natural falling and dipping of separate house flies in sterile water on counts of total microbial flora, non-haemolytic and haemolytic microorganisms (mean of five replicates-counts/ml) [1].

Natural falling and dipping in milk

Our findings show that the falling of house fly in sterile milk had a higher contamination level than the insects dipping which refers to the presence of some antimicrobial agents on the surface of house fly which descending in water, during dipping treatments as illustrated in Table 3. More remarkable findings were noticed in the means of bacterial counts after the dipping and falling treatments at different incubation periods as presented in Table 4, which declared that dipping treatments gave a considerably lower value. Although milk is an excellent medium for the proliferation of almost all microorganisms, the obtained results pointed out a progressive decline in different microbial counts after falling or dipping treatment, and this supports the suggestion of the presence of antimicrobial agents on the house fly.

Table 3: Counts of total microbial flora, non-haemolytic and haemolytic microorganisms as influenced by falling and dipping of house flies in sterile milk, counts/ml (17 samples) [1].

Table 4: Effect of incubation period on the counts of different microorganisms in contaminated milk with natural falling and dipping house flies (counts/ ml) [1].

Some previous studies pointed out similar results, which revealed that all media cultivated with right-wing extract were free of bacterial and fungal growth; however, the left-wing had bacterial and fungal growth [6]. This would conclude that the right fly wing is a new antibiotic revolution that needs more investigation in order to discover other antibiotics from the right fly wing. As well as, unveiled the nature of some antimicrobial agents on the house fly at the molecular level [2]. Therefore, it is worthwhile to investigate more in this field seeking for potentially new antimicrobial factors and antibiotics.

Contributions to the literature

• This report summarizes the study made by Baeshin, et al. to point out the precedence of exploring the results of the study [1].

• The study describes the effect of the natural falling and dipping of the house fly in water and milk on both pathogenic and non- pathogenic microorganisms.

Conclusion

The results suggest the existence of antimicrobial agents on the house fly, which opens the doors of the exploration of promising antimicrobial agents to serve in food hygiene and other public health categories. The observed results support the presence of antimicrobial agents on the house fly, which is a promising research field that might open the doors for the discovery of novel promising antimicrobial agents that may serve particularly in food science and generally in the fields of medicine, pharmaceuticals, and public health.

References

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