Microbial Antagonism in Relationships - Chapter 14

The normal microbiota can benefit the host by preventing the overgrowth of harmful microorganisms. It involves competition among microbes.

Microbial antagonism involves normal microbiota protecting the host against colonization by potentially pathogenic microbes by competing for nutrients, producing substances harmful to invading microbes, and affecting conditions such as pH and available oxygen.

Disease can result.

<p>In women, the pH levels of the vagina inhibit the overgrowth of yeast. The normal pH is about level 4, and disruption can allow yeast to flourish.</p> Signup and view all the answers

<p>Vaginitis (a vaginal infection).</p> Signup and view all the answers

<p>In the large intestines, cells produce bacteriocins, proteins that inhibit the growth of other bacteria, such as pathogenic Salmonella and Shigella.</p> Signup and view all the answers

<p>2, E. coli and Clostridium difficile.</p> Signup and view all the answers

<p>The relationship between the normal microbiota and the host, where at least one organism is dependent on the other.</p> Signup and view all the answers

<p>It is when one of the organisms benefits and the other is unaffected.</p> Signup and view all the answers

<p>commensals.</p> Signup and view all the answers

<p>Staphylococcus epidermidis, corynebacteria on the eye, and saprophytic mycobacteria in external genitals.</p> Signup and view all the answers

<p>Commensalism, mutualism, parasitism.</p> Signup and view all the answers

<p>It is when one organism benefits while the other is unaffected. An example is Staphylococcus epidermidis bacteria on the skin.</p> Signup and view all the answers

<p>It is when both organisms benefit. An example is E. coli bacteria (lavender) in the large intestine.</p> Signup and view all the answers

<p>It is when one organism benefits at the expense of the other. An example is H1N1 virus particles (orange) on a host cell (green).</p> Signup and view all the answers

<p>When the large intestines contain bacteria, such as E. coli, that synthesize vitamin K and B vitamins.</p> Signup and view all the answers

<p>They are parasites.</p> Signup and view all the answers

<p>Staphylococcus, Micrococcus, Enterococcus, Lactobacillus, Bacteroides, aerobic diphtheroids, Pseudomonas, Klebsiella, Candida albicans (fungus), Trichomonas vaginalis (protozoan) in the vagina.</p> Signup and view all the answers

<p>The lower urethra has a resident population; the vagina has its acid-tolerant population of microbes. Mucus and shedding prevent microbes from attaching, urine flow removes them, and the pH inhibits growth.</p> Signup and view all the answers

<p>Escherichia coli, Bacteroides, Fusobacterium, Lactobacillus, Enterococcus, Bifidobacterium, Enterobacter, Citrobacter, Proteus, Klebsiella, Candida (fungus).</p> Signup and view all the answers

<p>The large intestine has the largest numbers of resident microbiota because of moisture and nutrients. Mucus and shedding prevent attachment, and diarrhea flushes out microbes.</p> Signup and view all the answers

<p>Streptococcus, Lactobacillus, Actinomyces, Bacteroides, Veillonella, Neisseria, Haemophilus, Fusobacterium, Treponema, Staphylococcus, Corynebacterium, Candida (fungus).</p> Signup and view all the answers

<p>The mouth's abundant moisture, warmth, and food support large microbial populations on the tongue, cheeks, teeth, and gums.</p> Signup and view all the answers

<p>Staphylococcus aureus, S. epidermidis, aerobic diphtheroids, S. pneumoniae, Haemophilus, Neisseria.</p> Signup and view all the answers

<p>Some normal microbiota are potential pathogens, but their ability to cause disease is reduced by microbial antagonism. Nasal secretions and mucus help remove them.</p> Signup and view all the answers

<p>Propionibacterium, Staphylococcus, Corynebacterium, Micrococcus, Acinetobacter, Brevibacterium, Candida (fungus), Malassezia (fungus).</p> Signup and view all the answers

<p>Microbes in contact with skin don't become residents due to antimicrobial properties of sweat and oils. The skin barrier and low moisture inhibit many microbes.</p> Signup and view all the answers