<< Chapter < Page Chapter >> Page >

Currently, there is no universally accepted vaccine for Hansen’s disease. India and Brazil use a tuberculosis vaccine against Hansen’s disease because both diseases are caused by species of Mycobacterium . The effectiveness of this method is questionable, however, since it appears that the vaccine works in some populations but not in others.

a) Black tissue on end of nose. B) Small purple cells next to larger blue ones.
(a) The nose of a patient with Hansen’s disease. Note the lepromatous/multibacillary lesions around the nostril. (b) Hansen’s disease is caused by Mycobacterium leprae , a gram-positive bacillus. (credit a, b: modifications of work by the Centers for Disease Control and Prevention)
  • What prevents the progression from tuberculoid to lepromatus leprosy?
  • Why does Hansen’s disease typically affect the nerves of the extremities?

Leper colonies

Disfiguring, deadly diseases like leprosy have historically been stigmatized in many cultures. Before leprosy was understood, victims were often isolated in leper colonies, a practice mentioned frequently in ancient texts, including the Bible. But leper colonies are not just an artifact of the ancient world. In Hawaii, a leper colony established in the late nineteenth century persisted until the mid-twentieth century, its residents forced to live in deplorable conditions. National Park Service, “A Brief History of Kalaupapa,” Accessed February 2, 2016. http://www.nps.gov/kala/learn/historyculture/a-brief-history-of-kalaupapa.htm. Although leprosy is a communicable disease, it is not considered contagious (easily communicable), and it certainly does not pose enough of a threat to justify the permanent isolation of its victims. Today, we reserve the practices of isolation and quarantine to patients with more dangerous diseases, such as Ebola or multiple-drug-resistant bacteria like Mycobacterium tuberculosis and Staphylococcus aureus . The ethical argument for this practice is that isolating infected patients is necessary to prevent the transmission and spread of highly contagious diseases—even when it goes against the wishes of the patient.

Of course, it is much easier to justify the practice of temporary, clinical quarantining than permanent social segregation, as occurred in leper colonies. In the 1980s, there were calls by some groups to establish camps for people infected with AIDS. Although this idea was never actually implemented, it begs the question—where do we draw the line? Are permanent isolation camps or colonies ever medically or socially justifiable? Suppose there were an outbreak of a fatal, contagious disease for which there is no treatment. Would it be justifiable to impose social isolation on those afflicted with the disease? How would we balance the rights of the infected with the risk they pose to others? To what extent should society expect individuals to put their own health at risk for the sake of treating others humanely?

Bacterial infections of the nervous system

Despite the formidable defenses protecting the nervous system, a number of bacterial pathogens are known to cause serious infections of the CNS or PNS. Unfortunately, these infections are often serious and life threatening. [link] summarizes some important infections of the nervous system.

Table titled: Bacterial Infections of the Nervous System. Columns: Disease; Pathogen; Signs and Symptoms; Transmission; Antimicrobial Drugs; Vaccine. Disease: Botulism; Clostridium botulinum; Blurred vision, drooping eyelids, difficulty swallowing and breathing, nausea, vomiting,often fatal; Ingestion of preformed toxin in food, ingestion of endospores in food by infants or immunocompromised adults, bacterium introduced via wound or injection; Antitoxin; penicillin (for wound botulism)l; None. Disease: Hansen’s disease (leprosy); Mycobacterium leprae; Hypopigmented skin, skin lesions, and nodules, loss of peripheral nerve function, loss of fingers, toes, and extremities; Inhalation, possible transmissible from armadillos to humans; Dapsone, rifampin, clofazimin; None. Haemophilus influenzae type b meningitis; Haemophilus influenza; Nausea, vomiting, photophobia, stiff neck, confusion; Direct contact, inhalation of aerosols; Doxycycline, fluoroquinolones, second- and third-generation cephalosporins, and . carbapenems; Hib vaccine. Disease: Listeriosis; Listeria monocytogenes; Initial flu-like symptoms, sepsis and potentially fatal meningitis in susceptible individuals, miscarriage in pregnant women; Bacterium ingested with contaminated food or water; Ampicillin, gentamicin; None . Disease: Meningococcal meningitis; Neisseria meningitidis; Nausea, vomiting, photophobia, stiff neck, confusion; often fatal; Direct contact; Cephalosporins or penicillins; Meningococcal conjugate. Disease: Neonatal meningitis; Streptococcus agalactiae; Temperature instability, apnea, bradycardia, hypotension, feeding difficulty, irritability, limpness, seizures, bulging fontanel, stiff neck, opisthotonos, hemiparesis, often fatal; Direct contact in birth canal; Ampicillin plus gentamicin, cefotaxime, or both; None. Pneumococcal meningitis; Streptococcus pneumoniae; Nausea, vomiting, photophobia, stiff neck, confusion, often fatal; Direct contact, aerosols; Cephalosporins, penicillin; Pneumococcal vaccines. Disease: Tetanus; Clostridium tetani; Progressive spasmatic paralysis starting with the jaw, often fatal; Bacterium introduced in puncture wound; Penicillin, antitoxin; DTaP, Tdap.

Key concepts and summary

  • Bacterial meningitis can be caused by several species of encapsulated bacteria, including Haemophilus influenzae , Neisseria meningitidis , Streptococcus pneumoniae , and Streptococcus agalactiae (group B streptococci). H. influenzae affects primarily young children and neonates, N. meningitidis is the only communicable pathogen and mostly affects children and young adults, S. pneumoniae affects mostly young children, and S. agalactiae affects newborns during or shortly after birth.
  • Symptoms of bacterial meningitis include fever, neck stiffness, headache, confusion, convulsions, coma, and death.
  • Diagnosis of bacterial meningitis is made through observations and culture of organisms in CSF. Bacterial meningitis is treated with antibiotics. H. influenzae and N. meningitidis have vaccines available.
  • Clostridium species cause neurological diseases, including botulism and tetanus , by producing potent neurotoxins that interfere with neurotransmitter release. The PNS is typically affected. Treatment of Clostridium infection is effective only through early diagnosis with administration of antibiotics to control the infection and antitoxins to neutralize the endotoxin before they enter cells.
  • Listeria monocytogenes is a foodborne pathogen that can infect the CNS, causing meningitis. The infection can be spread through the placenta to a fetus. Diagnosis is through culture of blood or CSF. Treatment is with antibiotics and there is no vaccine.
  • Hansen’s disease ( leprosy ) is caused by the intracellular parasite Mycobacterium leprae . Infections cause demylenation of neurons, resulting in decreased sensation in peripheral appendages and body sites. Treatment is with multi-drug antibiotic therapy, and there is no universally recognized vaccine.

Fill in the blank

The form of meningitis that can cause epidemics is caused by the pathogen ________.

Neisseria meningitidis

Got questions? Get instant answers now!

The symptoms of tetanus are caused by the neurotoxin ________.


Got questions? Get instant answers now!

________ is another name for leprosy.

Hansen’s disease

Got questions? Get instant answers now!

Botulism prevents the release of the neurotransmitter ________.


Got questions? Get instant answers now!

________ is a neurological disease that can be prevented with the DTaP vaccine.


Got questions? Get instant answers now!

Tetanus patients exhibit ________ when muscle spasms causes them to arch their backs.


Got questions? Get instant answers now!

Short answer

A physician suspects the lesion and pustule pictured here are indicative of tuberculoid leprosy. If the diagnosis is correct, what microorganism would be found in a skin biopsy?

Discolored tissue.
(credit: Centers for Disease Control and Prevention)
Got questions? Get instant answers now!

Questions & Answers

sahi kon hai bhosri ke
saurabh Reply
define metabolism of carbohydrates with example
Thavasi Reply
what is sterilization a
the process of keep equipment free from bacteria
is it only bacteria?
no undesirable fungi and contamination also.
what is streak plate method
what is the biofilm
metabolism is the sum of all the biochemical reaction required for energy generation and use of that energy to synthesize cell materials from small molecules in environment.
what are granulocytes
Shawnitta Reply
granulocytes are type of WBCs which contains granules in the cytoplasm
suitable example for prokaryotes
Suvetha Reply
one of the possible early sources of energy was
uv radiation and lighting
e coli is the example of prokaryotes
archaea too
which is the specific virus causing typhoid
Jeremiah Reply
it's caused by a virulent bacteria called Salmonella Typhi
write the life cycle of HIV
Firomsa Reply
describe the internal and external structure of prokaryotic cell in terms of there appearance and functions
Lenia Reply
compare and contrast similar structures found in prokaryotic and eukaryotic cells
control of microorganisms
what is sterilization
how can a doctor treat a person affected by endospore forming bacteria in his/her wound?
Mambo Reply
define disinfectant
the process of killing
the process of killing microorganisms
a 28 years old woman come to your clinic with complain of fever painful genital blisters which express clear fluid when ruptured burning sensation around the bristers what is the diagnosis?
Ramadhani Reply
genital herpes caused by a virus called herpe simplex virus
what is the reference between selective medium and differential medium?
Tony Reply
the micro flora of air is transient why
Hello.... Am new here
essien Reply
welcome essien
welcome essien
I'm new here
Welcome Macpue!😊
classification of gram positive
lissa Reply
classify gram positive
catalase test is done to differentiate between staph and strep. as staph is catalase positive while strep is catalase negative then staph is differentiate further on coagulase positive and coagulase negative. staph aureus is coagulase positive while staph epidermidis is coagulase negative.
gram positive staph is further differentiated on sensitivity test and manitol salt fermentation test while gram positive strep is differentiated on hemolysis pattern
more about gramm positive
am back any gist
can i use the graph of bacterial growth for my master's thesis?
Christoph Reply
facultative anaerobic bavteria gives uniform turdibity in nutrient broth why?
Princess Reply
oils and waxes are not sterilized in autoclave
what is the function of paraffin
@ MAHI because they can grow all over the media from surface to the bottom as they can utilize oxygen or conduct fermentation in its absence.
2.@MAHI Autoclave uses steam under pressure. The steam cannot penetrate through oil and wax. Thus, dry heat sterilization is preferred than autoclave .
how nutirent agar can converted into blood agar
thank you
take a nutrient agar ........and add 5ml blood and put in it ...........!
nutrient agar +blood 5ml+ distilled water =blood agar .
mixed wellllll
why agar is not a neutrient source?
because it's a general purpose agar only use for growing bacteria
way is antigen
what is antigen
antigen is a foreign body that cause activation of antibody?
Antigen is a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.
thanks for that
what is pharmacology
a science that studies about the drug
hello ever one
Work hard
thanks alot
What is the major different between gram positive and gram negative bacteria.
bacteria kya hai
content of their cell wall
koi mujhse basic microbiology ki study k Lea book suggest kro .
Harley prescott

Get the best Microbiology course in your pocket!

Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Microbiology' conversation and receive update notifications?