Chapter 21
usually diagnosed by serology - looking for antibodies to
Borrelia bergdorferi
Two weeks after a backpacking trip in Tennessee, a hiker experienced flulike symptoms and noticed a red rash on his thigh. What is the likely cause of his illness? ( a. Treponema pallidum pertenue b. Borrelia burgdorferi c. Borrelia recurrentis d. Leptospira interrogans)
Borrelia burgdorferi
Cause of Lyme disease, initiating skin symptom:
Borrelia burgdorferi transferred by tick bite, erythema chronicum migrans
The smallest cellular microbes are (a. rickettsias b. mycoplasmas c. chlamydias d. both a and c )
Both rickettsias and chlamydias
The most common cause of bacterial gastroenteritis in the United States is (a. Vibrio parahaemolyticus b. Campylobacter jejuni c. Helicobacter pylori d. Vibrio cholerae )
Campylobacter jejuni
causes more bacterial diarrhea in the U.S. than any other organism.
Campylobacter jejuni
the organism has an antigen that looks like an antigen present on nerve cells, and the body's antibodies against C. jejuni begin attacking the nervous system.
Campylobacter jejuni
human pathogen which causes respiratory diseases
Chlamydia pneumoniae
causes "parrot fever" and can be contracted from psittacine birds such as parrots
Chlamydia psittaci
The most commonly reported sexually transmitted disease in the United States is caused by the bacterium (a. Mycoplasma genitalium b. Chlamydia trachomatis c. Chlamydophila proctitis d. Ureaplasma urealyticum)
Chlamydia trachomatis
is a wet prep, which means a drop of fluid from the patient is placed on a slide with a cover slip - it is not dried and stained like a gram stain.
Dark field test
extends to the palms and soles
(Rocky Mountain Spotted Fever)RMSF rash and in the secondary stage of syphilis.
first stages of syphilis is
1. primary stage painless chancre at the site of infection. This is the end of the infection for one-third of patients.
Second stage of syphilis
2. the second stage of the disease, an all-over body rash, extending even to the palms and soles. Two-thirds of patients
third stage of syphilis
3.third stage end of the disease; one third go to the tertiary stage of syphilis, in which large sores called gummas form, either inside or outside the body.
A major consequence of Campylobacter jejuni is the development of a type of paralysis called
Guillain-Barre
can colonize the stomach and remain present there, It causes no disease, but in some individuals it causes peptic ulcers. is curable with antibiotics that eliminate the bacteria.
Helicobacter pylori
is associated with stomach cancer and migraines in infected individuals.
Helicobacter pylori
can be diagnosed by looking inside granulocytes of neutrophils, eosinophils and basophils for the bacteria
Human Granulocytic Ehrlichiosis
significant difference between HGE (Human Granulocytic Ehrlichiosis) and HME (Human Monocytic Ehrlichiosi) is
Human Granulocytic Ehrlichiosis-HGE is more common in the northern part of the U.S., while Human Monocytic Ehrlichiosi-HME is more common in the southern part.
diagnosed by looking for inclusions in the monocytes, they only make up about 10% of the WBCs, so it usually takes longer to find and diagnose this disease than HGE (Human Granulocytic Ehrlichiosis)
Human Monocytic Ehrlichiosis, HME
the only spirochete that can be grown artificially in the lab. It is becoming more common in urban settings because of the large numbers of rodents in these areas.
Leptospira
the only spirochete which is environmental - it can be contracted by humans swallowing infected rat urine, or swimming in a fresh-water lake where infected animals have urinated.
Leptospira
is spread to humans from the bite of the nymph stage of the deer tick.
Lyme Disease
What genus is known as the smallest free living bacteria? has no cell wall and has sterols in the membrane
Mycoplasma
is a bacteria that does not possess a cell wall. Because of this, the shape is pleomorphic, CAN grow extracellularly,
Mycoplasma
Penicillin, lysozyme do not affect it, Cytoplasmic membrane contains sterols that increase strength, is usually diagnosed using DFA or serology.
Mycoplasma species
Cell helpful for diagnosing Human Granulocytic Ehrlichiosis
Neutrophils, are very common at least 50% of the WBCs should be neutrophils and the granules do not mask other inclusions, such as the bacteria. eosinophils and basophils are full of dark granules not very numerous, these cells are not helpful for diagnosis of this disease.
rash indicates loss of blood from the vessels, which can result in drop in blood pressure, compromising organs such as kidneys and heart.
Petechial rash
rash seen in Neisseria meningitidis and Toxic Shock Syndrome caused by Staphylococcus aureus.
Petechial rash
rash seen in Rocky Mountain Spotted Fever.
Petechial rash
The most severe rickettsial illness is caused by (a. Rickettsia typhi b. Rickettsia rickettsii c. Orientia tsutsugamushi d. Ehrlichia chaffeensis)
Rickettsia rickettsii
was discovered in the Rocky Mountains, but it is actually more common in the Appalachian Mountains and in the eastern U.S.
Rocky Mountain Spotted Fever
can cause long-term chronic infections that can lead to atherosclerosis, heart disease, even cancer.
Several bacteria, like Helicobacter
do not gram stain well, they are thin, can be visualized by dark field microscope, or by a silver stain
Spirochetes
Which of the following is not true of cholera? (a. The causative agent lives naturally in marine water. b. There is an effective vaccine for cholera. c. Strain 01 El Tor has been responsible for several pandemics. d. Rice-water stool is a symptom.)
There is an effective vaccine for cholera.
eye disease caused by Chlamydia trachomatis, a major cause of blindness worldwide. This is also the species which causes the most common bacterial sexually transmitted disease in the United States.
Trachoma
Which of the following organisms is transmitted via sexual contact? ( a. Treponema pallidum endemicum b. Treponema pallidum pertenue c. Treponema pallidum pallidum d. Treponema carateum)
Treponema pallidum pallidum
is still extremely common wherever potable water is compromised with human feces. this organism is a halophile, it survives easily in marine water. Most outbreaks of usually occur in areas near a seacoast.
Vibrio Cholera in the genus Vibrio
treponemal diseases that are not sexually-transmitted.
Yaws, pinta and bejel
Most human infections caused by species of Rickettsia (a. are acquired from fomites b. could be prevented by handwashing c. are transmitted via vectors d. are sexually transmitted)
are transmitted via vectors
Chlamydia pneumoniae is also associated with chronic diseases such as
atherosclerosis, heart disease, and arthritis.
associated with Lyme Disease.
bull's-eye rash, or erythema migrans, they are wonderful diagnostic feature of Lyme
typhus is caused by and is transmitted by?
by a rickettsia, and is transmitted person to person by body lice.
Which of the following diseases would be least likely in rural areas of the United States? (a. epidemic typhus b. Rocky Mountain spotted fever c. murine typhus d, lymphogranuloma venereum)
epidemic typhus
Treatment of chlamydial infections involves (a. erythromycin cream b. doxycycline creams c. surgical correction of eyelid deformities d. all of the above)
erythromycin cream,doxycycline creams,surgical correction of eyelid deformities
The bacterium that causes spotted fever rickettsiosis (RMSF) is more likely to infect a human (a. if an infected tick feeds for several hours b. when an infected tick initially penetrates the skin c. when contaminated tick feces dry and become airborne d. if the human is exposed to rodent feces containing the bacterium)
if an infected tick feeds for several hours
disadvantage of a wet prep Dark field microscopy
is actually not used much, since it requires specialized microscopy skills that are becoming more and more rare.
Advantage of a wet prep Dark field microscopy, besides its speed
is that the organisms continue to demonstrate motility.
Syphilis is curable by
penicillin at any stage, but any damage to the heart or brain as a result of long-term infection will be permanent.
The infective dose of Vibrio cholerae is
quite high - there must be enough bacteria present to survive passage through the low pH of the stomach.
the infected person loses so much fluid that death might occur within just a few hours of taking ill.
results of cholera is rice-water stools
One of the most effective treatments against cholera is
simply to replace fluids and electrolytes.
Historical journals have described gummas on patients. What disease most likely caused these lesions? (a. ornithosis b. syphilis c. trachoma d. pneumonia)
syphilis
Treponema pallidum causes
syphilis spirochete
During which stage of syphilis is penicillin ineffective? (a. primary syphilis b. secondary syphilis c. tertiary syphilis d. all of the above)
tertiary syphilis
three main pockets of Lyme Disease in the U.S
the Northeast, the Midwest, and California. By far the largest number of infections per capita is in the Northeast, with Connecticut being the highest.
Once Vibrio cholerae is in a human
the bacteria turns on its virulence factors, and it becomes more easily transmitted - the infective dose drops.
causes the mucosal cells of the intestinal tract to secrete fluid.
the cholera's toxin
If the source of Vibrio cholerae infection is environmental
the organism is less pathogenic than if the bacteria has passed through a human host.
is caused by the Enterobacteriaceae Salmonella typhi.
typhoid fever
