An eight month pregnant, thirty-two-year-old Caucasian female presents at the Emergency Room with a complaint of fever, malaise, cramps, and a non-productive cough. Her husband explains that ultrasound studies from their obstetrician revealed that this is a twin pregnancy. It has been uncomplicated until now. The mother is worried because she has felt fetal movements decline over the past three days.
Her symptoms began six days ago. Nothing extraordinary occurred around that time, except for her malaise, which she attributed to the twin pregnancy. Four days ago she developed a low grade fever that has continued up until now. This is her first pregnancy and she is very anxious about the safety of her babies. Over the past week, she has eaten normal, healthy food, although she admits to having a fondness for ice cream and other rich dairy products. She has been careful to avoid alcohol and other harmful substances since learning she was pregnant. She is allergic only to penicillin and has never had a serious illness until today. During the history portion of the interview she suddenly tells you she thinks she is experiencing contractions.
You take general vital signs and order an ultrasound study of her uterus. Her fever is 101.5 F, and her heart rate is 115 BPM, with a blood pressure of 160/70 mmHg. Her lung fields are clear, as is her heart with no evidence or rubs or murmurs. Twin#1 shows a complex, abnormal tachycardia, twin#2 shows no evidence of a fetal heartbeat. By now she is experiencing contractions every three minutes. You request preparation for an emergency Caesarian section from OB/GYN. Both twins are male. Twin#1 is delivered with no difficulty; no abnormalities are seen at this time. Twin#2 is delivered stillborn. One side of the placenta is abnormal, with evidence of multiple abscesses. The placenta is enlarged, and is pink-white in color.
Question 1 - Single Best Answer
What bacteria could have infected this woman's uterus?
A) Listeria, Neisseria, Group B Streptococci
B) Brucella abortus, Listeria, Group B Streptococci
C) Campylobacter, Brucella, Streptococcus
D) Staphylococcus, Listeria, Neisseria
E) Yersinia, Borrelia burgdorferi, Afipia felis
| GRAM STAIN OF PLACENTAL PUS | GM+ RODS, MANY PMNS |
|---|---|
| VDRL | NEGATIVE |
| WBC | 17X10^9/L |
| BLOOD CULTURE(MATERNAL) | small grey colonies on blood agar, blue green sheen |
| VAGINAL SWAB | NORMAL FLORA |
| URINE | NORMAL |
| CSF, TWIN#1 | STERILE, NORMAL |
| MENINGEAL BIOPSY, TWIN#2 | GM+ DIPTHEROIDS |
| Normal Lab Values |
Question 2 - Single Best Answer
What do you think is the cause of death of this twin?
A) Listeria
B) Corynebacteria
C) Neisseria
D) Group B Streptococci
Question 3 - Single Best Answer
What was the source of the bacteria?
A) insect
B) cat
C) ice cream
D) amniocentesis
E) sexual transmission via the husband
Question 4 - Single Best Answer
How did the bacteria get from the ice cream to the uterus?
A) the woman had a weird ice cream fetish.
B) she ate the ice cream and it passed directly to the uterus.
C) the bacteria colonized the GI tract, then spread to monocytes.
D) the bacteria colonized the GI tract, then spread to erythrocytes.
E) the bacteria have an enzyme that can penetrate the intestinal wall.
Fortunately the placenta was dichorionic, providing a physical barrier to infection of one fetus from the other. Based on the test results and her allergy to penicillin, you begin antibiotic therapy on the mother. She is told not to nurse.
Question 5 - Single Best Answer
Why was the mother advised not to breast feed the baby?
A) the antibiotic would be present in the milk, and harm the baby.
B) the mother is still at risk of shedding the Listeria.
C) bottled milk is better for the baby.
D) nursing would be debilitating for the mother.
E) A and B
The child is maintained on formula, given antibiotics, and carefully monitored. The infecting bacteria were identified as Listeria monocytogenes, a common animal bacterium which can be acquired from improperly handled food or unpasteurized milk. Listeria will grow at very cold temperatures, and ice cream has been a source of several epidemics.
Question 6 - Single Best Answer
Which of the following are virulence factors of Listeria?
A) endotoxin
B) listeriolysin
C) extracellular growth
D) complement resistance
E) sex pili
Question 7 - Single Best Answer
What other bacteria can be transferred to humans from milk that has been improperly pasteurized?
A) Brucella and Staphylococcus
B) Yersinia enterocolitica and Shigella
C) Borrelia burgdorferi and Brucella abortus
D) Brucella and Yersinia enterocolitica
E) Salmonella typhi
