Week 4 Flashcards
What is the standard media to grow Haemophilus influenzae?
chocolate agar
Haemophilus influenzae requires chocolate agar to grow. This medium has the necessary elements such as factor V (NAD) and factor X (hematin).
What are some infections caused by Haemophilus influenzae?
Haemophilus influenzae can cause epiglottitis, otitis media, and meningitis. While the other diseases listed can be bacteria-related, they are not typically associated with this bacteria.
Which strains of Haemophilus influenzae are commonly associated with causing meningitis?
Type B
When is the most appropriate time to vaccinate children against Haemophilus influenzae?
2 and 18 months
What type of bacteria is Haemophilus influenzae?
Gram-negative
The filamentous hemagglutinin in Bordetella pertussis is responsible for which function?
attachment to the respiratory epithelium
What is the primary method of transmission for Bordetella pertussis?
respiratory droplets
Legionnaires’ disease (caused by Legionella pneumophila) may present with low levels of what in the blood?
hyponatremia
What laboratory test might be performed for a rapid diagnosis of Legionnaires’ disease?
urine antigen test
What are the primary components found in the growth media agar for Legionella pneumophila?
cysteine, iron, buffered charcoal
Which stain is necessary in order to visualize Legionella pneumophila?
silver stain
What kind of bacteria is Brucella?
gram-negative
Which of the following is the most common reservoir for Brucella?
farm animals
What is a common reservoir for Francisella tularensis?
rabbits
Which of the following does Yersinia pestis cause when it establishes infection in humans?
Yersinia pestis, the bacterium responsible for causing bubonic and pneumonic plague, causes lymphadenopathy in humans. Lymphadenopathy refers to the swelling of lymph nodes, which is a characteristic feature of bubonic plague. The bacteria enter the lymphatic system and cause inflammation of the lymph nodes, leading to painful, enlarged buboes.
Bacillary angiomatosis is a disease caused by Bartonella henselae. This condition typically affects people who:
Bacillary angiomatosis, caused by Bartonella henselae, predominantly affects immunocompromised individuals, particularly those living with HIV/AIDS.
Besides fever and a history of a cat scratch, what is a common presentation of cat scratch disease?
Cat-scratch disease frequently presents with swollen regional lymph nodes, especially in the axilla. This is in addition to fever and usually a history of a cat scratch or bite.
What effect does severely low magnesium (Mg2+) levels have on PTH secretion?
Severely low levels of magnesium (Mg2+) inhibit PTH secretion. While magnesium plays less of a role in the regulation of PTH than calcium (Ca2+), its levels still influence PTH release. Normally, low Mg2+ results in increased PTH release; however, when Mg2+ levels are extremely low, it paradoxically inhibits PTH secretion. This inhibition can exacerbate hypocalcemia, as PTH is necessary for maintaining normal blood calcium levels.
How does PTH influence vitamin D metabolism?
Parathyroid hormone (PTH) promotes the conversion of vitamin D into its active form, calcitriol (1,25-dihydroxyvitamin D3), in the kidneys. This active form then facilitates increased calcium absorption in the intestines, contributing to the regulation of blood calcium levels.
How does parathyroid hormone (PTH) affect phosphate homeostasis in the body?
PTH regulates phosphate homeostasis primarily by increasing its excretion in the urine. It achieves this by inhibiting the reabsorption of phosphate in the proximal convoluted tubule of the kidney. This action, known as phosphaturia, helps to prevent hyperphosphatemia, which can occur when phosphate levels are too high and complex with calcium, potentially leading to decreased serum calcium levels.
What is the space called that is between the inner and outer membrane of a gram-negative bacteria?
periplasmic space
Protein A is a virulence factor found on which bacteria?
S. aureus
A 22-year-old female presents with dysuria and increased urinary frequency. Urinalysis shows hematuria. Urine culture identifies bacteria that grow as pink colonies on MacConkey’s agar. Which of the following best describes this growth medium?
selective and differential
It suppresses the growth of gram-positives through the addition of bile salts and crystal violet (so its selective)
It can differentiate between those bacteria which can ferment lactose (which turn red/pink) and those that cannot (which are clear)
The O, H, and K antigens are used for serotyping certain bacteria. What does each stand for?
O= outer polysaccharide portion of LPS
H= flagellar protein
K= capsule
Of the enterobacteriaceae, which are lactose positive?
“KEE” bacteria
Klebsiella
E. coli
Enterobacter
On MacConkey agar, enterobacteriaceae which bacteria will turn pink? Which will remain colorless?
ferment lactose = pink
no fermentation = colorless
On eosin methylene blue agar, which bacteria will turn a green metallic color?
E. coli
This bacteria’s major presentations is UTI, neonatal meningitis, GI infection (traveler’s diarrhea), and opportunistic infections
E. coli
This variant of E. coli is the most common cause of traveler’s diarrhea. It secretes enterotoxins that drive the loss of water from cells and it “heat labile” toxin functions like cholera toxin.
Enterotoxigenic E. coli (ETEC)
This variant of E. coli causes watery diarrhea, cramping, and some progress to hemolytic uremic syndrome. It is commonly transmitted through uncooked animal products.
Enterohemorrhagic E. coli (EHEC) (STEC)
Which enterobacteria is indole positive?
E. coli
E. coli are catalase ____ and oxidase _____.
positive, negative
Shigella is a gram-____ rod, lactose ____, catalase _____, oxidase _____, and H2S _____.
negative, negative, positive, negative, negative
On Hektoen’s agar or Salmonella-Shigella agar, shigella will turn which color?
it will remain colorless
Salmonella turns black
Salmonella is H2S ___ so it produces ____ colonies on Hektoen agar.
positive, black
Which bacteria is responsible for causing typhoid fever?
salmonella
This bacteria appears as mucoid colonies and causes a currant jelly sputum
Klebsiella pneumoniae
Klebsiella is indole ____ and lactose ____.
negative, positive
Enterobacter cloacae is indole ____ and lactose _____
negative, positive
Serratia marcescens is lactose ___ and indole ___. It has a ____ pigment.
negative, negative, red
This bacteria exhibits “swarming” or a growth over the entire plate
Proteus mirabilis and Proteus vulgaris
Increased inflammatory signals released from adipose tissue has what effect on glucose uptake and lipolysis?
decreases glucose uptake and increases lipolysis
The tendency of patients to displace feelings that appropriately belong to other important people onto the physician.
transference
Dr.’s reaction to the patient which may stem from own personal experiences. The response may be out of character for the physician.
countertransference
Which transporter is responsible for the reabsorption of glucose in the kidney proximal convoluted tubule?
SGLT1
The presence of autoantibodies against GAD65 in type 1 diabetes mellitus is measured by what?
immunoassay like ELISA
In normal metabolic regulation, insulin sensitivity and insulin secretion are ____ related.
inversely
This occurs when the body cannot produce any or very little insulin. It is typically seen in type 1 diabetes, where autoimmune destruction of pancreatic beta cells leads to severe insulin deficiency. Patients with absolute insulin deficiency need exogenous insulin for survival.
Absolute insulin deficiency
This is when the body’s production of insulin is insufficient to meet its needs, despite insulin still being produced. It is commonly associated with type 2 diabetes, where insulin resistance means that more insulin is required to maintain glucose homeostasis. Despite increased insulin secretion, the insulin response is not enough to effectively control blood glucose levels.
Relative insulin deficiency
A higher HOMA-IR means what?
higher insulin resistance
The pancreas secretes increasing amounts of insulin resistance by compensate for insulin resistance and maintain normal glucose levels.
Hyperinsulinemic compensation
The majority of obese subjects do not develop T2DM due to this.
Hyperinsulinemic compensation
Hypertrophic adipose tissue releases high amounts of this which can deposit in the liver and muscle tissue?
FFAs
TG and HDL-c have this type of relationship
inverse
What is the most likely cause of muscle insulin resistance in a patient with T2DM?
Reduced intracellular insulin signaling
52-year-old male with BMI of 28 kg/m2 presents with fasting glucose of 147 mg/dL, elevated TG, low HDL, high LDL and elevated C-peptide level. Which of the following best characterizes the patient’s condition?
relative insulin deficiency
What effect does increased hepatic insulin resistance have on gluconeogenesis?
Hepatic insulin resistance generally leads to increased gluconeogenesis because insulin normally inhibits this process. When insulin signaling is impaired in the liver, gluconeogenesis (glucose production by the liver) is less inhibited, leading to higher blood glucose levels.
Insulin resistance leads to ‘diabetic dyslipidemia’ and cardiovascular disease which means what?
increased TGs, increased small dense-LDL-cholesterol, decreased HDL-c
Changes in ____ and ___ are typically not observed in insulin resistance and are not part of diabetic dyslipidemia
total cholesterol and LDL-cholesterol
In which measure of disease is “person-time at risk” an integral part of the denominator?
incidence rate
An indirect inguinal hernia passes lateral to which structures?
inferior epigastric vessels
