The document discusses efflux pumps in bacteria. It begins by noting that efflux pumps contribute to antibiotic resistance and are involved in bacterial pathogenesis. There are five major families of efflux transporters - ATP-binding cassette (ABC), resistance-nodulation-division (RND), small multidrug resistance (SMR), major facilitator superfamily (MFS), and multidrug and toxic compound extrusion (MATE). The RND family is especially effective at generating multidrug resistance in gram-negative bacteria. Efflux pumps export various substrates like antibiotics, toxins, and metabolites using secondary active transport driven by proton or sodium ion gradients. Inhibitors of efflux pumps have potential to restore drug susceptibility in multidrug-

1. Presenter:
Mahsa jalili
MSc in Medical Microbiology
efflux pumps
1

2. Abstract:
 Infectious diseases remain one of the principal causes of
morbidity and mortality in the world .
 Efflux pumps are elements that antibiotics are effective in
resistance and are involved in the pathogenesis of bacteria .
 efflux pumps are important for processes of detoxification of
intracellular
metabolites, bacterial virulence in both animal an Man hosts, and
etc .
 So today we're in a selection pressure for antibiotic use and for
the treatment of bacterial infections are a new development .
2

3.  Efflux as a mechanism for antibiotic resistance was first
described in 1980 .
 Multidrug efflux pumps cause serious problems in cancer
chemotherapy and the treatment of bacterial infections.
 In Gram negative bacteria, the pumps belonging to the
resistance-nodulation-division (RND) family are especially
effective in generating resistance.
3

4.  Antimicrobial resistance has been considered the new challenge
of the 21st century for example : Salmonella enterica ,
Escherichia coli ,
 Different studies have demonstrated that MDR pumps are
capable of extruding not only antibiotics but also antiseptics.
4

5. Functional role of MDR pumps in clinical
and
nonclinical environments.5

6. The importance of efflux pumps:
 In general it can be said:
 Promotes the excretion of drugs and chemicals are.
 Metabolites and toxins that repel bacteria
 Microorganisms against antibiotics and chemicals, toxins, stress and
protect
 The survival of microorganisms in different environments.
 The supply of materials for the synthesis of bacterial surface structures
involved
 In balancing solutions, ionic homeostasis and balance are important.
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7. Classification:
 Efflux pump that was first detected : Efflux pumps was for a
family of tetracycline
 Bacterial efflux transporters are classified into five major
superfamilies, based on the amino acid sequence and the
energy source used to export their substrates.
 In the prokaryotic kingdom there are five major families of efflux
transporters.
 (ATP)-binding cassette (ABC) superfamily
 the resistance-nodulation-division (RND)family ,
 the small multidrug resistance (SMR) family
 the major facilitator superfamily(MFS)
 the multidrug and toxic compound extrusion (MATE) family
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8.  ABC: membrane proteins that translocate variety of substrates
across extra- and intra-cellular membranes
48 known ABC transporters; divided into 7 subfamilies of
proteins
 RND: Fall into 7 phylogenetic families
3 Restricted to Gram – ive Bacteria; other 4 either restricted to
Gram + ive or represented in both
Also in bacteria, archaea and eukarya
 SMR The smaller size . is unusual bacteria. Its pumps contain
only 100-120 amino acid
8

9.  MFS: One of two largest families
17 MFS Families
Present in bacteria, archaea and eukarya
 MATE :
14 Phylogenetic Families
Also in bacteria, archaea and eukarya .
It has the same size mfs
9

10. Classification:
Schematic representation of the main types of bacterial efflux
systems10

11. Gram-positive bacteria
Gram-
negativebacteria
11

12. Energy used in the efflux pump :
 The energy source:
 ABC transporters are dependent on ATP hydrolysis;
)The primary active transport(
 MFS, RND and SMR are proton-driven efflux pumps.
 MATE transporters consist of a Na/H drug antiporter
system.
)Secondary active transport(
12

13. Gram-negative species with known efflux
systems:
 Haemophilus
influenzae
 Campylobacter jejuni
 Helicobacter pylori
 Vibrio
parahaemolyticus
 Vibrio cholerae
 Neisseria
gonorrhoeae...
Salmonella Typhimurium
 Shigella dysenteriae
 Klebsiella pneumoniae
 Enterobacter aerogenes
 Serratia marcescens
 Proteus vulgaris
 Citrobacter freundii...
 Bacteroides fragilis...
 And ….
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14. 14

15. The most important mechanisms of drug resistance:
 Inactivating
 Change the form of the drug
 The aim of antibiotic succession and delegation
 Increase the amount of target
 Reduced affinity:
 Recombination
 Modification enzymes
• Efflux pumps
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16.  Important note :
 The resistance who efflux pump caused by antibiotic depends on
the nature of microorganisms and substrate
16

17. Structure of drug efflux systems:
 In Gram-positive bacteria:
 A cytoplasmic membrane transport proteins that recognize
specific substrate. and the resistance.
 In Gram-negative bacteria:
 3 component in a system:
Two transport proteins within the membrane.
A periplasmic lipoprotein adapter
17

18. 18

19. ABC tranceporters :
 In contrast with prokaryotes,the major mechanism of efflux in
eukaryotes is dependent on proteins that derive their transport
energy from the hydrolysis of ATP.
 Has a membrane-binding region of the cytoplasmic membrane
is in addition to the Alpha Helix to allow them The energy of ATP
hydrolysis to transport the drug, unlike other gradient used for
this purpose are proton exchange membrane of the
electrochemical gradient.
 Is an arsenic/antimony pump that is responsible for resistance to
the antimonial drug Pentostam in leishmania
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20. ABC tranceporters :
 ABC 200 amino acid, domains specific areas ABC, which is the
second hydrophobic combination of 6 alfa hlyksmy.
 The presence of walkers areas A, B sequence LSGGQ on all
members of the family.
20

21. E.coli
E.coli
S.Typhimurium
Bacillus
subtilis
Eukaryotes
21

22. The SMR family :
 The unusual bacteria found
 Of the 100 amino acids that made the four-helix
 For example : EmrE is in E.coli
 QacH-2 resistance in Staphylococcus aureus causes a number
of disinfectants.
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23. The MFS family :
 In eukaryotes, bacteria and Archaea are available.
 MFS are made of 400 amino acids arranged in 12 Helix
membrane and a cytoplasmic loop between helices 6 and 7 are
large.
 Mfs transport of drugs in two classes be:
 1- Class B: Transport tetracycline in E Coli
 2-class k: Transport tetracycline in Staphylococcus aureus
• MFS characterized by multi-drug pumps that to be anti ports
drug / proton acts and the transmission becomes very large
sugar and drugs.
23

24. 24

25. RND transporters :
 Typical emerged were larger than 1,000 amino acids. 12-helix
structure. They have a great second or subsequent
intracytoplasmic Periplasmic between helices 1 and 2, 7 and 8.
 There are more gram-negative bacteria.
 Pump compounds: toxic metal ions, lipophilic drugs such as
tetracycline, quinolones, and beta-lactamase and
chloramphenicol factors chemotherapy.
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26. 26

27. Structure :
 DNA structure is composed of 3 components:
 1-AcrA: inner membrane.
 2-AcrB: inner membrane.
 3-TolC: in the outer membrane.
 The third monomer forming the inner membrane creates an area
that extends Periplasmic..
27

28. TOLC PROTEIN;
 Is a multifunctional protein. Moving in small drugs and toxins
polypeptide involved.for example: hemolysin .
 TolC is divided into two domains:
 1-domain beta : in the outer membrane.
 2-domain alpha : in the periplasmic space.
 TolC several actions have to cross the outer membrane
periplasmic substrates.
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29. 29

30. β-barrel :
 Opens the outer membrane.
 Beta consists of 12 strings and are arranged in a right-handed
barrel.
30

31. Α-helical :
 12 left-handed filament is composed of two types of grape that
are
 Short
 Tall
 Alpha Helix Coils-Coiled arranged in the area and the
composition and structure of alpha and beta binding steadily
alpha helix, like a belt around it were shorter.
31

32. 32

33.  This substrate system:
 Aminoglycosides
 Tetracycline
 Fluoroquinolones
 Chloramphenicol
 Trimethoprim
33

34. 34

35. 35

36. MATE transporters :
 Of 450 amino acids that have been arranged in 12 Helix These
trans Porter Na or protons act as anti ports.
 NorM resistance in Vibrio parahaemolyticus color,
aminoglycosides and fluoroquinolones cause.
 YdhE in E.Coli is a cationic resistance to antibiotics cause
 MepA in the transfer tetracycline Staphylococcus aureus,
detergents and paints as well.
 PepM in Pseudomonas aeruginosa substrate fluoroquinolones,
is ethidium bromide and disinfectants.
36

37.  The pump substrates include:
 Gentamicin
 Ciprofloxacin
 Erythromycin
 Trimethoprim
37

38. Genetic of the efflux pump E.coli:
 Efflux system in E Coli:
 Chromosome
 Transferable elements (plasmids, transposons,
Integron)
38

39.  There are various regulators in E. Coli:
 Including : SdiA ,Sox ,Rob ,Mar A
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40. Efflux pump genes in Salmonella :
40

41.  Salmonella has a specific regulator, RamA, which controls the
expression ofacrABin response to environmental signals. We
suggest that
 RamA is a master regulator ofacrABand that the AcrAB induction
pathway inSalmonellais different from that inE. coli. In one
pathway, bile binds to the RamA protein, which is then
 converted from a low to a high activity state. In the other
pathway, indole may activateramAtranscription to induceacrAB.
41

42. Inhibitors :
 Inhibitors of efflux pumps have great potential as
pharmacological agents that restore the drug suseptibility of
multidrug resistant bacterial pathogens
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43.  High-potential pharmacological agents that can be multi-drug
resistant pathogens return sensitivity to the drug.
 Example:
 Phenylalanine, arginine beta - naphthyl amide
Phenyl-Arginyl ß N-naphtylamide
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The end