A mixture of S.aureus and the enteric bacteria E.coli was placed onto the skin of the fingertips of a volunteer. The volunteer immediately touched one of their inoculated fingertips to nutrient agar plate #1 and then waited 30 minutes and touched a different inoculated finger to nutrient agar plate #2. After incubating the plates overnight, plate #1 grew both, while plate #2 grew only S.aureus. Explain why by discussing the antimicrobial protein(s) or peptide(s) responsible for this first line of defense. Solution First line of defense is surface activity by skin epithelia, mucous membrane cells that produce lysozymes and ciliated cells. These lysosomes are the antimicrobial protein(s) or peptide(s) responsible for this first line of defense against mixture of S.aureus and the enteric bacteria E. coli on plate #2, in which only S. aureus exerted \"resistance\" against the \"lysozyme protein\" due to acquiring of \"protein-resistance genes”, followed by transferring them via horizontal gene transfer to other bacterial species Plate #1 grew both because both the species have exerted resistance against first line defense proteins such as lysozymes by generating the antigens, as these are chemical molecules that activates host immune system and it causes virulence to the host. PAMPs are specific pathogen associated molecular patterns that specifically composed of polysaccharides and polynucleotides of pathogens. These are exotoxins or endotoxins, or nucleotide sequences of virions. Explanation: First line of defense is surface activity by skin epithelia, mucous membrane cells that produce lysozymes and ciliated cells against Staphylococcus infection. Wound is infected with a common wound infecting bacteria, Staphylococcus aureus, and Staphylococcus epidermis. This bacterial species resists the host first line of defense either by producing resistance to the lysozymes produced by host tissue or by producing inactivating products to inactivate those host first line of defense mediators..

1. A mixture of S.aureus and the enteric bacteria E.coli was placed onto the skin of the fingertips of
a volunteer. The volunteer immediately touched one of their inoculated fingertips to nutrient agar
plate #1 and then waited 30 minutes and touched a different inoculated finger to nutrient agar
plate #2. After incubating the plates overnight, plate #1 grew both, while plate #2 grew only
S.aureus. Explain why by discussing the antimicrobial protein(s) or peptide(s) responsible for
this first line of defense.
Solution
First line of defense is surface activity by skin epithelia, mucous membrane cells that produce
lysozymes and ciliated cells. These lysosomes are the antimicrobial protein(s) or peptide(s)
responsible for this first line of defense against mixture of S.aureus and the enteric bacteria E.
coli on plate #2, in which only S. aureus exerted "resistance" against the "lysozyme protein"
due to acquiring of "protein-resistance genes”, followed by transferring them via horizontal gene
transfer to other bacterial species
Plate #1 grew both because both the species have exerted resistance against first line defense
proteins such as lysozymes by generating the antigens, as these are chemical molecules that
activates host immune system and it causes virulence to the host. PAMPs are specific pathogen
associated molecular patterns that specifically composed of polysaccharides and polynucleotides
of pathogens. These are exotoxins or endotoxins, or nucleotide sequences of virions.
Explanation:
First line of defense is surface activity by skin epithelia, mucous membrane cells that produce
lysozymes and ciliated cells against Staphylococcus infection. Wound is infected with a common
wound infecting bacteria, Staphylococcus aureus, and Staphylococcus epidermis. This bacterial
species resists the host first line of defense either by producing resistance to the lysozymes
produced by host tissue or by producing inactivating products to inactivate those host first line of
defense mediators.