Micro exam 5 Flashcards
(100 cards)
1
Q
What is intoxication ?
A
person ingest TOXIN produced by pathogen
2
Q
what is infection?
A
person ingest PATHOGEN which enters GI tract and multiplies
3
Q
A
4
Q
what is the gram stain of Staphylococcus aureus?
A
Gram (+) cocci
5
Q
what is the gram stain of Bacillus cereus?
A
Gram (+) rods
6
Q
what is the gram stain of Clostridium botulinum?
A
Gram (+) rod
7
Q
what is the gram stain of Clostridium perfringens?
A
Gram (+) rod
8
Q
Discuss the disease process of - Staphylococcus aureus; signs and symptoms that result?
A
- produces toxins: enterotoxins
- very heat stable
- inhibits water absorption
S/S: severe diarrhea and vomiting; No fever for 24 hours
9
Q
Discuss the disease process of Bacillus cereus ; signs and symptoms that result?
A
if food contains endospores, spores survive cooking, germinate as food is cooling or left unrefrigerated
S/S: vomiting and diarrhea
10
Q
Discuss the disease process of Clostridium botulinum ; signs and symptoms that result?
A
incubation: 18-36 hours
treatment: Anti- toxin immediately
S/S: nausea, vomiting, double vision, difficulty swallowing, fatigue, paralysis
11
Q
Discuss the disease process of Clostridium perfringens.
A
- major source (meat/meat dish) containing endospores
- food is cooked: bacteria die: endospore survive
- endospore germinate during cooling/storage
- bacteria increase to enormous concentration
- food eaten: intestines sporulate and enterotoxin produced
Incubation: 6-24 hours
12
Q
signs and symptoms of Clostridium perfringens ?
A
- Acute abdominal pain, cramps, diarrhea, nausea
- NO vomiting or fever
13
Q
what is the most common cause of food poisoning?
A
Staphylococcus aureus
14
Q
Of the 4 major causes of food poisoning, What 2 species form endospores?
A
- Clostridium perfringens
- Bacillus Cereus
15
Q
Which of the four species produce a neurotoxin?
A
- Clostridium botulinum
16
Q
How does the toxin work in Clostridium botulinum?
A
- natural toxins act as a neurotoxin affecting CNS to cause paralysis
- Block nerve transmission
- toxin gene is located on a prophage
17
Q
what is the gram stain of Enterobacteriaceae family?
A
Gram (-) rods
18
Q
what is the gram stain of the Vibrionaceae family?
A
Gram (-) rods
19
Q
What key biochemical test differentiates the Enterobacteriaceae family from the Vibrionaceae family of bacteria?
A
the biochemical text for Enterobacteriaceae is oxidase (-) and Vibrionaceae (+)
20
Q
what are the virulence factor of Enterobacteriaceae ?
A
- colonization factors (adherence)
- Secretion of 1 or more toxins that cause fluid loss
- Ability to invade intestinal epithelial cells
21
Q
what are the virulence factor of Vibrionaceae?
A
22
Q
what is the species in Enterobacteriaceae family that causes human disease?
A
pathogenic strains of E.coli
23
Q
what are the pathogenic strain of E.coli?
A
- Enterotoxigenic strains
- Enteropathogenic strains
- Enteroaggregative strains
- Enterohemorrhagic strains
24
Q
what is the species in Vibrionaceae family that causes human disease?
A
Vibrio cholera and Campylobacter
25
what is the transmission route of Enterobacteriaceae family ?
Fecal Oral
- animals like cattle, sheep, goats, pigs and turkeys
- infected people
26
what is the transmission route of Vibrionaceae family?
fecal-oral
- ingestion of contaminated food or water.
- raw milk, meat, chicken
- direct or indirect contact with feces of an animal
27
In the Enterobacteriaceae family, state what is meant by the ‘O’, ‘H’, and ‘K’ antigens.
O antigens: outer membrane LPS
H antigens: capsular antigens
K antigens: flagellar antigens
28
A virulent strain of E coli is O157:H7. This can cause hemolytic colitis and hemolytic uremic syndrome. Discuss these diseases
- shiga-like toxins I and II
- inhibit protein synthesis
- Kills cells
- survives: animal reservoirs, food, water, soil
- Acid resistant (pH<3)
29
Explain how the toxin produced by Vibrio cholera works.
- Produce toxin, cholera toxin (CT)
- encoded by prophage gene
- induces rapid loss of electrolytes and fluids
- can cause shock, collapse, often death
- S/S: vomiting and water diarrhea
30
What is Guillain-Barre Syndrome?
- leading cause of acute paralysis in the US
31
how can Guillain-Barre Syndrome develop?
Autoimmune reaction following:
- infection with bacteria or virus
- vaccination (rare)
32
what are the bacteria that enter the GI tract, adhere and invade the epithelial cells ?
- Shigella
- Salmonella sps. (other than Salmonella typhi),
- E. coli (invasive strains)
33
what is the gram stain of shigella ?
Gram (-) rod
34
what is the gram stain of salmonella sps
Gram (-) rod
35
what is the gram stain of invasive E.coli?
Gram (-) rod
36
what is the disease process and transmission route of shigella ?
fecal- oral
1. INGESTION of organism
2. PROLIFERATION to very large numbers in small intestine.
3. Bacteria INVADES epithelial cells of large intestine
4. Severe Diarrhea with blood and mucous
37
what is the disease process and transmission route of salmonella ?
fecal- oral
1. Bacteria INGESTED
2. Bacteria INVADE
3. TOXINS produced
4. during acute phase of illness
- 1 bill orgs/gm feces shed
- 2-7 days
- shed for several months
38
what is the disease process and transmission route of E. coli ?
fecal- oral
1. organism INGESTED
2. INVADES intestinal epithelial cells
3. produces TOXINS which inhibit fluid absorption and KILLS epithelial cells
39
What species of Shigella is most common in the U.S.?
Shigella sonnei
39
What species of Salmonella is most important in the U.S.?
Salmonella enterica
40
what is the bacteria that enter the GI tract, but do not stay in the GI tract and become systemic?
- Salmonella typhi (typhoid fever)
- Listeria monocytogenes
- Yersinia enterocolitica
- Yersinia pseudotuberculosis.
41
What is the gram stain of Salmonella typhi (typhoid fever)?
Gram (-) rod
42
what is the gram stain of Listeria monocytogenes ?
Gram (+) rod
43
what is the gram stain of Yersinia enterocolitica?
Gram (-) rod
44
what is the gram stain of Yersinia pseudotuberculosis ?
Gram (-) rod
45
Outline the disease process, including transmission route of Salmonella typhi
1. bacteria ingested
2. Inflammation of intestines
3. fever declines
4. bacteria invades lymph nodes
5. organism is not killed in macrophages
6. bacteria infect various tissues and organs
transmission: feces of other humans
46
Outline the disease process, including transmission route of yersinia
1. bacteria ingested
2. organism invades intestinal epithelial cells
3. invades lymph nodes and possibly blood stream
Transmission: fecal-oral (wild and domestic animals)
47
Outline the disease process, including transmission route of Listeria monocytogenes
1. bacteria ingested
2. invades epithelial cells and phagocytes
3. resist destruction in phagocyte: multiplies
transmission: dairy products, poultry, meat, and produce
48
What 3 factors significantly decreased typhoid fever in the U.S. during the 20th century?
1. pasteurization of milk
2. chlorination of water
3. improved methods of sewage treatment
49
Salmonella typhi (and Shigella) are only transmitted by infected humans, not animals. true or false ?
true
50
Name which species is especially dangerous for pregnant women and the immunosuppressed.
Listeria monocytogenes
51
Name which species can cause painful swelling of the lymph nodes; pain can mimic an appendicitis.
Yersinia
52
Name organisms, other than bacteria, that can cause ‘intoxication’
- Fungal toxins
- Algal toxins
53
Protozoa are grouped into 4 major divisions based on means of locomotion. what are they?
- Pseudopods
- Cilia
- Flagella
- Non- motile
54
List the name of each of the 5 major protozoa discussed and its means of motility.
1. Entamoeba histolytica- pseudopods
2. Balantidium coli- Cilia
3. Giardia intestinalis- Flagella
4. Toxoplasma gondii- Non-motile
5. Cryptosporidium- Non- motile
55
What is the transmission route/disease process of Entamoeba histolytica?
1. transmission of cyst excreted in feces
2.cyst wall digested
3. cyst converts to trophozoite on last portion of small intestines
4. trophozoite binds to epithelial cell of large intestines and multiplies
5. organism releases enzymes that dissolve tissue
Transmission: human-human/fecal-oral
56
What is the transmission route/disease process of Balantidium coli?
large, oval, ciliated: common source swine; transmission fecal-oral, commonly from pigs
57
What is the transmission route/disease process of Giardia intestinalis?
1. source
2. organsim is excreted in feces
3. cyst are ingested
4. in intestines trophozoite emerges
5. organism attaches firmly to human intestinal wall
large, oval, ciliated: common source swine; transmission fecal-oral, commonly from pigs
58
What is the transmission route/disease process of Toxoplasma gondii?
1. organism is ingested
2. phagocytized by macrophages
3. resist destruction in macrophages: multiplies
4. host cell ruptures
5. release of more organisms in body
undercooked meat and cats; potentially dangerous in immunosuppressed patients and pregnant women
59
What is the transmission route/disease process of Cryptosporidium?
1. organism ingested
2. penetrates intestinal cells and multiplies
3. Oocytes are released in the gut lumen and excreted
common in lakes/streams; not believed to be pathogenic until AIDS; potentially dangerous in immunosuppressed patient
60
Is Norovirus RNA or DNA?
RNA
61
Is Rotavirus RNA or DNA?
RNA
62
What are the local viral infections?
1. Norwalk-like viruses
2.Rotavirus
63
what are the systematic viruses ?
Enteroviruses and Hepatits viruses
64
what is the disease process for norovirus and the S/S?
1. entry and transmission
2. attachment and infection
3. damage to intestinal lining
4. immune response
5. shedding and recovery
S/S- fever and diarrhea
65
what is the disease process for rotovirus and the S/S?
1. entry and transmission
2. infection of the gut
3. damage to intestinal lining
4. fluid secretion and diarrhea
5. immune response and recovery
S/S- fever, watery diarrhea, vomiting
66
which of these viruses (nora/rotavirus) can be very dangerous for infants and why?
- Rotavirus because infants lack maternal antibodies
- can be severe due to loss of fluids, dehydration, and possible shock
67
What is the vaccine for the Rotavirus?
living attenuated virus
68
Which Intestinal viruses enter the GI tract, but then become systemic illnesses
Enteroviruses:
- Polio
- Coxsackie
- Echovirus
- Hepatitis A
69
Are Enteroviruses RNA or DNA ?
RNA
70
What is the disease process and S/S for polio?
1. ingestion
2. infects GI tract
3. invades tonsils and lymph nodes
4. invades blood: migrate to meninges
S/S: fever, headache, nausea, sore throat, myalgia
71
what are the two vaccines for enterovirus and what do they contain?
salk - (inactivated) formalin killed viruses of the 3 types
sabin- live attenuated viruses of 3 types
72
INFO!!
Enteroviruses
- Polio transmitted human-human most commonly by fecal contamination of water supplies.
- more prevalent in warm weather
73
What are the Hepatitis virus?
- Hepatitis A
- Hepatitis B
- Hepatitis C
- Hepatitis D
- Hepatitis E
74
What is hepatitis?
inflammation of the liver
75
Which hepatitits viruses are DNA? RNA?
RNA: Hepatitis A, C, D, E
DNA: Hepatitis B
76
List the mode of transmission for each virus
Hep A: Fecal-oral
Hep B: Blood/bodily fluids
Hep C: Blood/bodily fluids
Hep D: Blood/bodily fluids
Hep E: Fecal-oral
77
Discuss the relative length of incubation and whether chronic carriers exist for each type of hepatitis virus.
Hep A: 15-40 days, No chronic carriers
Hep B: 50-180 days, chronic carriers
Hep C: 14-150 days, Chronic carriers
Hep D: 21-49 days ? Chronic carriers
Hep E: 15 to 60 days, No chronic carriers
78
What are the immunizations for the hepatitis?
Hep A: inactivated whole virus
Hep B: recombinant
Hep C: vax in development
Hep D: no?
Hep E: no?
79
Which type of hepatitis virus is especially concerning for pregnant women?
Hep E
80
What are the three types of Helminths?
- Roundworms (cylindrical bodies)
- Flukes (flat, oval bodies)
- Tapeworms (flat, ribbon-like bodies)
81
How is helminths it transmitted?
Commonly transmitted by the eggs of the worm
82
What is Enterobius vermicularis ?
- A pin worm
- common infection especially in children
83
what is the process of pin worms?
- Eggs are ingested;
- hatch into larvae;
- larvae develop into adult male and female worms which mate;
- female migrates to the anal opening to deposit the eggs;
- result is intense itching;
- the child scratches and picks up the eggs which can be transmitted directly or indirectly to someone else
84
Define ‘opportunistic organism’. in UTI
An opportunistic organism is a microorganism that normally does not cause disease in a healthy individual,
but can cause infection when the person’s immune defenses are weakened or when it gains access to a normally sterile part of the body.
85
What is a ‘nosocomial infection’?
A nosocomial infection is an infection that is acquired in a hospital or healthcare setting.
86
List the species which is the most common cause of UTIs.
E.coli
87
what is cystitis?
UTI in the urinary bladder
88
what is pyelonephritis?
UTI in the kidney
89
Discuss the specific criteria used to diagnose a UTI.
gram (-) rods: E.coli, Klebsiella, Proteus, Enterobacter, Pseudomonas
gram (+) cocci: Staphylococcus species, Enterococcus
Cystitis: urgent/painful urination, WBC in pee, fever
Pyelonephritis: fever and backache
90
Define the term ‘vaginitis’.
inflammation/infection of the vagina
91
Candida albicans is yeast and is NOT the leading endogenous organism involved in the etiology of vaginitis. true or false?
False, it is the leading endogenous organism
92
List the conditions under which this organism can cause disease.
- weakened immune systems
- neonates
- UTI
93
Trichomonas vaginalis is a flagellated protozoa that can be sexually transmitted to cause vaginitis.
Explain why vaginal pH is an important factor in helping to prevent this infection.
It can predispose to infection, the ability to inhibit the growth of pathogen
94
Define ‘vaginosis’
imbalance of vagina flora
95
What is Gardnerella Vaginalis?
small gram (-) rod, leading cause vaginosis
96
Is this a common infection in sexually active women?
Yes
97
How is vaginosis diagnosed?
clue cells and fishy odor
98
what are clue cells?
vaginal epithelial cells covered with tiny rods
99
what can infection be a factor in?
premature births and low birth weight infants
