Anaerobic Bacteria

Clostridium species

deadly + opportunistic, via exotoxins. Gram positive and anerobic. All can produce spores

C. tetani habitat + infection

in soil and in intestinal flora; causes tetanus/lockjaw when spores in soil are introduced into wounds (nails, glass)

C. tetani characteristics

long + slender w no capsule w flagella, round spore drum-stick appearance. Spore diameter > vegetative cell

C. Tetani symptoms + immunity

Binds to ganglisoside recptors, causing spastic paralysis, muscle contractions + spasms can be fatal; vaccination of tetanus toxoid

C. perfingens habitat + stats

found in soil + feces. 3rd most common cause of food poisoning (can be ingested w no harm); shortest generation time @ 6.3 minutes in thioglycolate medium. non motile but can move.

C. perfringens treatment

Without treatment, death occurs in 2 days. antitoxin and antibiotic therapy. amutation + death rare.

C. perfinigens infection

wound contamination + meat and poultry (poor prepared or left standing too long). the enterotoxin (CPE) survives up to 74C, can be detected in food + poop. incubation time 6-24 hours. Spores can withstand cook temp and germination if left standing.

C. Perfinigens lab diagnosis

Nagler’s reaction = cultured onto yolk media plate. one side anti-alpha toxin, with a streak on both sides. If opaque on toxin side that means licithinase activity.

C. Perfingens lab results

Positive: Indole, Licithinase; Negative: catalase, Lipase. Stormu fermentation in Litmus milk. . stool cutlure can be tested for toxin

C. Botulinum morphology + stats

rod-shaped and produces protein neurotoxin. Produces toxin that can kill w just 10 ng

C. Botulinum habitat + transmission

soil + sediment of lakes, ponds, decaying vegetation, intestinal tract of birds, fish + mammals, found in blood stream, duodenum, and muscle synapses; eating uncooked foods/spores heat resistant.

C. Difficile

shows up after antibiotic uses reduces intestinal normal flora. produces enterotoxin

pseudomembranous Colitis

when antibiotics reduce normal intestinal flora; abdominal pain, watery diarrhea and leukocytosis. 27-44% deaths if untreated. treated by stopping antibiotic use or specific therapy (vancomycin).

Strict anaerobes stuff

Lacks superoxide dismutase, catalase, and peroxidase; killed by oxygen, and no ox. phospho (fermentation instead). disease through muscle and abscesses.

Identification problems

air in sample + transportation stops growth. Identification takes a few days. normal flora can contaminate

Virulence factors

Anti-phagocytic capsule, tissue destructive enzymes, beta-lactamase production, and superoxide dismutase production.

Anaerobic infections characteristics

Most come from flora, those with predisposing conditions (tissue related), synergistic with aerobes (e. coli consumes O2, and they promote other bacteria), and complex.

Hints to anaerobic infection

Infections in continuity to mucosal surfaces, Infections with tissue necrosis and abscess formation, Putrid odor, Gas in tissues, Polymicrobial flora, Failure to grow in the lab

BACTEROIDES FRAGILIS

non-spore former, causes disease after abdominal surgery; low toxic endotoxin with different liposaccharide structure.