1. By Abdoulie k. Ceesay

2. OUTLINE
 Abbreviation
 Introduction
 History
 Class of Antibiotic
 Production
 Types of leucocin
 Use
 Mechanism of action
 Side effect & Resistance
 Literature cited

3. Abbreviation
• AMP : Antimicrobial peptide
• LAB : Lacticacid bacteria

4. Introduction
 Leucocine A,B,C,N and Q
 Bacteriocin
 Proteinaceous toxins
 Kills similar strain of bacterial growth
 Narrow spectrum of antibiotics

5. History
 Bacteriocin
 A. Gratia in 1925
 Was involved in ways to kill bacteria
 Colicine discovered
 killed E. Coli
 Leucocine discovered later

6. Class of antibiotic
 Class II bacteriocins
 Small peptide
 30-70 amino acids
 Heat resistant (100 deg. For 20 min. )
 Stable at low pH values
 3.9 kDs

7. Production
 Leucocin
 Ribosomally synthesized AMP
 Bacteriosin

8. TYPES
 Leucocin A-UAL 187
 Leuconostoc gelidum
 Listeria monocytogenes
 Adopts a beta-structure in membrane-
mimicking environments

9. TYPES CONT’d
 Leucocin B-Ta11a
 Leuconostoc carnosum
 Listeria monocytogenes
 Heat stable
 Bacteria class IIA
 Aerobic and anaerobic

10. TYPES CONT’d
 Leucocin C
 Leuconostoc mesenteroides
 Target LAB
 Adopts a beta-structure in membrane-
mimicking environments

11. TYPES CONT’d
 Leucocin N and Q
 Leuconostoc pseudomedenteriodes
 Class IId
 Target Listeris innocua ATCC 33090,
Listeria monocytogenes ATCCBSS-679,
Enterococcus faecalis JCB 5803 etc.

12. Use
 Produce protein toxins
 inhibits growth of similar bacterial strain
 Use in food preservation
 Milk , lactobacillus or LAB
 Root canal-treated teeth, enterococcus
faecalis
 Foodborne pathogen, listeria
monocytogenes
 Used in leucorrhoea (Medical)
 Posibility of cancer treatment

13. Mechanism of action
 Proteinaeous toxins
 Kills by pore-formation
 Porins
 Ionic imbalance
 death

14. Side effect & Resistance
 No side effects
 L. Monocytogene
 Mutaion
 Enzyme IIAB

15. Literature cited
 http://bactibase.pfba-lab-tun.org/BAC042
 http://journal.frontiersin.org/article/10.3389/fmicb.2014.00
241/full
 Papathanasopoulos, M. A.; Dykes, G. A.; Revol-Junelles,
A. M.; Delfour, A.; Von Holy, A.; Hastings, J. W. (1998).
"Sequence and structural relationships of leucocins A-, B-
and C-TA33a from Leuconostoc mesenteroides
TA33a".Microbiology (Reading, England). 144 ( Pt 5):
1343–1348. PMID 9611809.
 Fregeau Gallagher, N. L.; Sailer, M.; Niemczura, W. P.;
Nakashima, T. T.; Stiles, M. E.; Vederas, J. C. (1997).
"Three-Dimensional Structure of Leucocin a in
Trifluoroethanol and Dodecylphosphocholine Micelles:
Spatial Location of Residues Critical for Biological Activity
in Type IIa Bacteriocins from Lactic Acid

16.  ANY QUESTION ?ANY QUESTION