The Soldier Fly

Immunities to antibiotics are increasing rapidly in many species throughout the world. Have you ever wondered what scientists are doing about it? Well the answer is right in front of us. The following review is about an article that tests the effects of extracts from black soldier fly larvae. These little flies can be found in almost any country and are usually very common. There are many species of these in New Zealand.

                    

The following article is written by Won-Hyung CHOI, Ji-Hye YUN, Jong-Phil CHU and Ki-Back CHU and is called:

Antibacterial effect of extracts of Hermetia illucens (Diptera: Stratiomyidae) larvae against Gram-negative bacteria.

It can be found here: http://onlinelibrary.wiley.com.ezproxy.lincoln.ac.nz/doi/10.1111/j.1748-5967.2012.00465.x/pdf

The article begins by explaining our need for new antibiotics as species are developing resistances to the strains we already have. Many species of insects and plants have already been tested for their viability. Many insects have antimicrobial substances that are located within or on the surface of their digestive tract; this is to prevent microbial infection. For this reason, this has been utilised in Europe for the treatments of burns and open wounds. The introduction continues to describe other species that have been used for their antimicrobial larvae such as the house fly (Musca domestica).

The black soldier fly’s larvae was previously used for the bioconversion of dairy manure, conversion of organic materials and forensic science; for determining human postmortem duration.

The equipment used to test the soldier fly is described next, it was bought from several places. Luria broth, agar powder, petri dishes, paper discs and many other chemicals and reagents were described.

The methods section first describes the extraction of the soldier fly larvae. 600g of larvae was rinsed three times with distilled water to remove any unwanted material. The larvae were extracted with 6 L of n-hexane, chloroform, ethanol, methanol and distilled water (H2O) at room temperature for 24 hours.

The extracted larvae were tested on gram-negative and gram-positive bacteria.

The results have shown that there was no inhibition of gram positive bacteria; however gram-negative bacteria seemed to be inhibited.

The following table is taken from the article and sums up the results of the tests, There was a huge difference in effect when comparing gram-positive with gram-negative bacteria.

The soldier fly larvae possess unique properties that may be utilized for various defense purposes, which contain various antibacterial peptides as effective inhibitory substances against many pathogens. However, the presence of an antimicrobial substance derived from the larvae has not been found yet. The purpose of the article was to identify potential antibacterial properties, as well as antibacterial effects of the soldier fly’s larvae extracts. Because the extracts only showed antimicrobial activity against a few bacteria, more study will have to be performed to see if this species is viable. 

This article explains everything in great detail and provides very thorough results and explanations. Its amazing what can be found in things such as little and as common as a soldier fly.