An investigation into the antibacterial properties of Lucilia cuprina flies

Done by: Lee Liu Yi, Sherlene Goh Shi Li, Evelyn Lim Kim BoonHwa Chong Institution (College)

Mr Carl Baptista, Mrs Sim-Wang Hui Ming, Mrs Judith Cheng

ABSTRACTThe formation of biofilms on indwelling catheters has posed a problem to the medical industry.

Resistance of the bacteria to multiple antibiotics worsens the problem.

Hence, our project seeks to investigate the body fluids of Lucilia cuprina flies as previous research done on maggots proved that antibacterial compounds were present in that species.

In this study, the body fluids of Lucilia cuprina flies were extracted and screened against four strains of bacteria: Escherichia coli, Staphylococcus epidermidis, Pseudomonas putida and Micrococcus luteus

We hypothesize that the body fluids of Luci l ia cuprina flies do have antibacterial properties.

HYPOTHESIS

Preparation of body fluids of Lucilia cuprina flies

METHODS AND MATERIALS

Lucilia cuprina flies were frozen

Bodies crushed with

glass rod

Dilution with sterile water

Centrifuged at 7600 rpm for 10 mins

Serial dilution 9 centrifuge

tubes A-I prepared

Samples incubated overnight

Tubes A-D: diluted to power

-6

Tubes E-I: diluted to power -5

Culture in tubes then plated onto

agar plates

Agar plates incubated

overnight at 37°C

Tubes Reagents (ml)

Nutrient broth

Sterile Water

Fly

fluid

E. coli Staph. E P. putida M. Luteus

A 8.0 1.0 - 1.0 - - -

B 8.0 1.0 - - 1.0 - -

C 8.0 1.0 - - - 1.0 -

D 8.0 1.0 - - - - 1.0

E 8.0 1.0 1.0 - - - -

F 8.0 - 1.0 1.0 - - -

G 8.0 - 1.0 - 1.0 - -

H 8.0 - 1.0 - - 1.0 -

I 8.0 - 1.0 - - - 1.0

The results of the experiments show that the body fluid of Lucilia cuprina flies do have antibacterial properties, and is particularly effective against gram positive bacteria.

The body fluids of Lucilia cuprina flies showed antibacterial effects against Staphylococcus epidermidis, a gram positive bacteria that is commonly found on the skin of humans. Hence, this compound incorporated into surgical wipes to be used prior to surgery and in antiseptic lotions.

DISCUSSION

The body fluids of Lucilia Cuprina flies do have anti bacterial properties

The body fluids of Lucilia Cuprina flies are more effective against gram-positive bacteria

CONCLUSIONS

ACKNOWLEDGEMENTS

RESULTS

Gram negative Gram positive

A vs. F (E. coli) C vs. H (P. putida) B vs. G (Staph. E) D vs. I (M. lut)

0

10

20

30

40

50

60

70

80

90

Escherichia coli Staphylococcus epidermidis

Pseudomonas putida

Micrococcus luteus

89

19 211312

4.8×10-6 1.9 5.7×10-6

Mill

ions

Chart showing colony count of control and sample plates

Control tubes

Sample tubes

Fig 1: Cartoon of a flyPicture taken from:

http://www.sleezybarbhorsewear.com/webpictures/Fly.gif

Fig 2: Lucilia cuprina flyTaken from: http://www.nku.edu/~dahlem/2006CollectingWeb/2006CollWeb%20Images/BlowFly2.JPG

Pictures taken by Lee Liu Yi

Our group would like to take this opportunity to thank the following people:

Our external mentor, Mr Carl Baptista as well as our teacher mentors, Mrs Sim-Wang Hui Ming and MrsJudith Cheng

The staff at Origin Scientia for their support and valuable input

Mdm Lim Cheng Fui, Mr Ng Kim Hoe and the rest of the staff at the SRC for their patience and guidance