Summary Alternatives for antibiotics

Molecular Basis of Bacterial Infections Evelien Floor



Alternatives for antibiotics
ESKAPE pathogens cause most problems in the clinic because they are resistant to antibiotics:
 Enterococcus faecium
 Staphylococcus aureus
 Klebsiella pneumoniae
 Acinetobacter baumannii
 Pseudomonas aeruginosa
 Enterobacter species
The number of new antibiotics is decreasing so alternatives are required. An alternative in case of
antibiotic resistance is antibody therapy. With this method, patients are treated with antibodies that
boost the host immune response to help clear the infection.

Antibodies
An antibody (Ab), also known as an
immunoglobulin (Ig), is a large, Y-
shaped protein produced mainly
by plasma cells that is used by the
immune system to neutralize
pathogens. The main function of
antibodies is to enhance innate
immune mechanisms. There are
two forms of antibodies: B cell
receptors (BCR) and secreted
immunoglobulins. There are five
different immunoglobulin forms:
 IgG  majority of antibody-based immunity against invading pathogens
 IgE  allergy and parasites
 IgD  receptor on resting B cells and activate basophils
 IgM  early immunity and C activation
 IgA  blocks colonization in the mucosa

Antibodies neutralize bacterial infections via: opsonization, complement activation and
neutralization.
Neutrophils
Neutrophils are the first
line of defence against
bacterial infections.
They take up opsonized
bacteria and break them
down with the use of
ROS and proteases.
Neutrophils can also kill
bacteria extracellularly
via neutrophil




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