Dr. Wilk’s Note Guide for Microbiology Unit
10
MICRO BIO 2100 Dr. Wilk’s Note Guide for Microbiology Unit 10
USLO 10.1
Vocabulary to define:
• Pleomorphic-capable of having a variety of shapes
• Endothelial cells-an epithelial cell found in blood vessels and lining the heart
Bacterial Diseases of the digestive system
• Bacillus cereus
o Disease associated with pathogen-food poisoning/intoxication-found in pasta or rice
o Signs and symptoms-symptoms begin within a few hours & include nausea, pain
& abdominal cramps. Vomiting or diarrhea may also be present depending on the
enterotoxin present. Has been known to cause death.
o Virulence Factors-makes 2 enterotoxins
▪ One causes vomiting
▪ Other causes diarrhea
o Transmission-found in the soil & is often associated with grains. The bacteria in food
will form and endospore. Vegetative bacteria make enterotoxins. Enterotoxins can be
secreted into food that is left out too long or not cooked properly.
o Treatment-antibiotics and fluids
• Bacillus anthracis
o Disease associated with pathogen-anthrax
o Signs and symptoms-rare in the US, prompt treatment is necessary for good
outcomes. Without treatment, gastrointestinal anthrax is fatal in about 40% of cases.
o Virulence Factors-has a capsule, lethal toxin (LT), and edema toxin (ET).
o Transmission-enters through the GI system causes gastrointestinal anthrax. Can
be contracted through eating meat contaminated with the bacterium.
o Treatment-antibiotics; penicillin, doxycycline, ciprofloxacin
• Clostridium botulinum
o Disease associated with pathogen-botulism
o Signs and symptoms-nausea, vomiting, constipation, diarrhea, abdominal
cramps, difficulty swallowing, drooping eyelids, blurred vision
o Virulence Factors-usually the endospore of C. botulinum are in food and germinate
within the food allowing the production of the neurotoxin. The person ingests the
neurotoxin and enters the bloodstream causing the paralysis at the NMJ. Forms
the neurotoxin BoNT.
o Transmission-Associated with improperly canned foods. The neurotoxin is
ingested through the digestive tract.
o Treatment-Administration of the anti-toxin for the BoNT. This will only stop progression
and not reverse any damage to the NMJ already done. Over time, neurological functions
may be regained over a period of months or years.
• Clostridium difficile
o Disease associated with pathogen-C-diff infection
1
,Dr. Wilk’s Note Guide for Microbiology Unit
10
o Signs and symptoms-toxins cause damage to intestinal tract causing a
pseudomembranous colitis, watery and or bloody diarrhea, stomach
cramping, dehydration, fever, and loss of appetite. In older people, death can
result.
o Virulence Factors-produced toxins TcdA and TcdB
o Transmission-C. diff is part of the normal microbiota of normal healthy people. When
antibiotics disrupt the balance of the normal intestinal microbiota, Clostridium difficile
is allowed to overgrow causing symptoms. Also caused by unwashed hands. Hand
sanitizer does not kill spores.
o Treatment-Stopping antibiotics and using metronidazole or vancomycin. Other
treatment options may include fecal transplant from a healthy donor. Probiotics
can help to preserve the normal flora once the infection is under control.
• Clostridium perfringens
o Disease associated with pathogen-Gastroenteritis
o Signs and symptoms-diarrhea and abdominal cramps usually develop within 8-12hrs
and resolves within 24hrs
o Virulence Factors-enterotoxins
o Transmission-Found in undercooked food and the endospore will germinate and
secrete enterotoxins. Endospores that are ingested can also germinate in the
intestines.
o Treatment-Supportive care and replacement of electrolytes
• Escherichia coli
o Disease associated with pathogen-food poisoning
o Signs and symptoms—watery diarrhea, occasionally with a fever or vomiting
o Virulence Factors-fimbriae allow attachment, more virulent strains
produce enterotoxins, toxins are similar to cholera or shiga toxins
o Transmission-Normal inhabitant of lower GI tract. The most common means of
transmission is through contaminated food or water from improper hand
hygiene.
o Treatment-most are self-limiting and only require supportive care such as replacing
electrolytes. Other more virulent strains may require antibiotics, but these are
rarely used due to the risk of antibiotic resistance and the potential of hemolytic
urea syndrome.
• Helicobacter pylori
o Disease associated with pathogen-peptic ulcers
o Signs and symptoms-can be an inhabitant of some people and be asymptomatic.
Symptoms are nausea, lack of appetite, burping, bloating, and weight loss. Some
people will develop ulcers and some have risk of stomach cancer.
o Virulence Factors-Produces toxins Vac A. Attached using pili. Produces an
exoenzyme urease to neutralize stomach acid and allow for the bacteria to survive.
o Transmission-Transmitted through contaminated food or water. Recent research has
shown it is possible to transmit between people from close contact or sharing food
and drink.
o Treatment-Triple therapy with antibiotics and an antacid to decrease stomach acid
2
, Dr. Wilk’s Note Guide for Microbiology Unit
10
that the bacteria prefer.
• Salmonella
3
10
MICRO BIO 2100 Dr. Wilk’s Note Guide for Microbiology Unit 10
USLO 10.1
Vocabulary to define:
• Pleomorphic-capable of having a variety of shapes
• Endothelial cells-an epithelial cell found in blood vessels and lining the heart
Bacterial Diseases of the digestive system
• Bacillus cereus
o Disease associated with pathogen-food poisoning/intoxication-found in pasta or rice
o Signs and symptoms-symptoms begin within a few hours & include nausea, pain
& abdominal cramps. Vomiting or diarrhea may also be present depending on the
enterotoxin present. Has been known to cause death.
o Virulence Factors-makes 2 enterotoxins
▪ One causes vomiting
▪ Other causes diarrhea
o Transmission-found in the soil & is often associated with grains. The bacteria in food
will form and endospore. Vegetative bacteria make enterotoxins. Enterotoxins can be
secreted into food that is left out too long or not cooked properly.
o Treatment-antibiotics and fluids
• Bacillus anthracis
o Disease associated with pathogen-anthrax
o Signs and symptoms-rare in the US, prompt treatment is necessary for good
outcomes. Without treatment, gastrointestinal anthrax is fatal in about 40% of cases.
o Virulence Factors-has a capsule, lethal toxin (LT), and edema toxin (ET).
o Transmission-enters through the GI system causes gastrointestinal anthrax. Can
be contracted through eating meat contaminated with the bacterium.
o Treatment-antibiotics; penicillin, doxycycline, ciprofloxacin
• Clostridium botulinum
o Disease associated with pathogen-botulism
o Signs and symptoms-nausea, vomiting, constipation, diarrhea, abdominal
cramps, difficulty swallowing, drooping eyelids, blurred vision
o Virulence Factors-usually the endospore of C. botulinum are in food and germinate
within the food allowing the production of the neurotoxin. The person ingests the
neurotoxin and enters the bloodstream causing the paralysis at the NMJ. Forms
the neurotoxin BoNT.
o Transmission-Associated with improperly canned foods. The neurotoxin is
ingested through the digestive tract.
o Treatment-Administration of the anti-toxin for the BoNT. This will only stop progression
and not reverse any damage to the NMJ already done. Over time, neurological functions
may be regained over a period of months or years.
• Clostridium difficile
o Disease associated with pathogen-C-diff infection
1
,Dr. Wilk’s Note Guide for Microbiology Unit
10
o Signs and symptoms-toxins cause damage to intestinal tract causing a
pseudomembranous colitis, watery and or bloody diarrhea, stomach
cramping, dehydration, fever, and loss of appetite. In older people, death can
result.
o Virulence Factors-produced toxins TcdA and TcdB
o Transmission-C. diff is part of the normal microbiota of normal healthy people. When
antibiotics disrupt the balance of the normal intestinal microbiota, Clostridium difficile
is allowed to overgrow causing symptoms. Also caused by unwashed hands. Hand
sanitizer does not kill spores.
o Treatment-Stopping antibiotics and using metronidazole or vancomycin. Other
treatment options may include fecal transplant from a healthy donor. Probiotics
can help to preserve the normal flora once the infection is under control.
• Clostridium perfringens
o Disease associated with pathogen-Gastroenteritis
o Signs and symptoms-diarrhea and abdominal cramps usually develop within 8-12hrs
and resolves within 24hrs
o Virulence Factors-enterotoxins
o Transmission-Found in undercooked food and the endospore will germinate and
secrete enterotoxins. Endospores that are ingested can also germinate in the
intestines.
o Treatment-Supportive care and replacement of electrolytes
• Escherichia coli
o Disease associated with pathogen-food poisoning
o Signs and symptoms—watery diarrhea, occasionally with a fever or vomiting
o Virulence Factors-fimbriae allow attachment, more virulent strains
produce enterotoxins, toxins are similar to cholera or shiga toxins
o Transmission-Normal inhabitant of lower GI tract. The most common means of
transmission is through contaminated food or water from improper hand
hygiene.
o Treatment-most are self-limiting and only require supportive care such as replacing
electrolytes. Other more virulent strains may require antibiotics, but these are
rarely used due to the risk of antibiotic resistance and the potential of hemolytic
urea syndrome.
• Helicobacter pylori
o Disease associated with pathogen-peptic ulcers
o Signs and symptoms-can be an inhabitant of some people and be asymptomatic.
Symptoms are nausea, lack of appetite, burping, bloating, and weight loss. Some
people will develop ulcers and some have risk of stomach cancer.
o Virulence Factors-Produces toxins Vac A. Attached using pili. Produces an
exoenzyme urease to neutralize stomach acid and allow for the bacteria to survive.
o Transmission-Transmitted through contaminated food or water. Recent research has
shown it is possible to transmit between people from close contact or sharing food
and drink.
o Treatment-Triple therapy with antibiotics and an antacid to decrease stomach acid
2
, Dr. Wilk’s Note Guide for Microbiology Unit
10
that the bacteria prefer.
• Salmonella
3
