|
A
Actinomyces
These
endogenous anaerobic organisms characteristically grow as filamentous
branching Gram-positive bacteria. Actinomyces israelii is the
etiologic agent for actinomycosis. Some species are members of the normal
oral and GI flora.
Lecture
Outline | Case Study
Anaerobic Bacteria
The
anaerobes are organisms that grow only in the absence of molecular oxygen.
There are several major groups, listed below as links to separate topics and
their slide sets. A general set of information on anaerobic bacterial culture
is also shown below.
See: Bacteroides
Clostridium botulinum
Clostridium difficle
Clostridium perfringens
Clostridium
tetani
THE
CULTURE OF ANAEROBIC ORGANISMS: Powerpoint Slides
Anthrax
Caused
by a gram-positive spore forming bacillus, and carried in some animal
populations, anthrax is considered a zoonotic disease. In the last decade,
this organism has gained prominence because of its potential for military
use.
Go to Bacillus
anthracis
Antibiotic Resistance
Increasingly
a concern for medical practitioners, antibiotic resistance is an area where
rapid change means frequent updates on the status of a particular pathogen.
Click on the links below for theoretical discussions, laboratory techniques
for determining pathogen resistance and CDC updates.
Powerpoint
Slides | Laboratory
| Web Links | On
the Farm
Anatomical
Sites of Bacterial Infection
There
are many ways to categorize bacterial agents. One way is to describe where on
the human body they are likely to be found, and where they are likely to
cause infection. Click the link below to find out more.
Lecture Outline |
Arboviruses
In the U.S.
viral diseases transmitted by arthropods include the encephalitides and
Colorado tick fever
virus. These are less severe than arboviral diseases found in more tropical
climates, but some are on the rise as agents of human infection. West Nile virus in particular is of increasing interest
as an agent of human disease transmitted during the summer months via
mosquito bites.
Powerpoint
Slides | Web Links
Arthropods of Medical Importance
Many
bacterial, rickettsial, parasitic and viral diseases are transmitted by the
bite of an arthropod. In the U.S.
the arthropods are most commonly mosquitos or ticks. But, there are even
arthropods that cause direct "infestations" like those that cause
itch mites and head lice. Read about them at the links below.
Lecture
Notes | Web Links
Aseptic Meningitis
Viral
meningitis is also called aseptic meningitis, mainly to distinguish it from
bacterial meningitis. Unlike the disease caused by bacterial agents, viral
meningits typically runs its course without complications, although an
increased risk of seizures can be problematic in young children.
Go to Viral
Meningitis
Aspergillosis and Aspergillus fumigatus
Aspergillus fumigatus and other members of the Aspergillus
genus are associated with allergies, bronchitis and "Sick Building
Syndrome". Find out more about this opportunistic fungal pathogen at the
links below:
Powerpoint
Slides | Web
Links
B
Bacillus
anthracis
This
bacterial agent is a gram-positive spore forming bacillus, and carried in
some animal populations, especially in developing countries like Africa. It causes the disease anthrax, which is
considered a zoonotic disease. In the last decade, this organism has gained
prominence because of its potential for military use.
Powerpoint
Slides | Web Links
Bacterial
Culture, Basic
The
basics of bacterial culture on agar are shown at the laboratory link below. Topics
include pure culture techniques, antibiotic resistance concepts and several
types of staining methodology.
BASIC BACTERIAL CULTURE
LABORATORY
See Also Specific Bacterial Culture Pages:
Anaerobic
Culture
Differential and
Selective Bacterial Culture
Escherichia coli
and Gram Negative Enteric Bacteria
Neisseria and Haemophilus
Species
Staphylococcus
species
Streptococcus
species
Throat
culture
Bacterial
Genetics
The
basic principles of bacterial genetics are presented here including
complementation, recombination, genetic elements, transfer of genetic
information and mutation.
Lecture
Bacterial
Growth and Death
Bacterial
growth dynamics are determined by available nutrients and the inhibitory
effects of metabolic wastes. Also important to this topic are concepts of
physical agents like ultraviolet light and chemical agents that can death to
bacterial cells through a number of mechanisms.
Lecture
Bacterial
Meningitis
Bacterial
meningitis can be caused by a number of different species; however, Neisseria
meningitidis is an important pathogen that continues to cause meningitis,
especially within specific patient populations.
Powerpoint
Slides | Laboratory
Bacterial Physiology
Bacteria
use many different types of physiological mechanisms. Those that cause human
disease are a little less complicated. Many are facultative anaerboes,
meaning that they can switch metabolism to take advantage of available
nutrients.
Powerpoint
Slides
Bacterial
Staining
Staining
methodology. The link is to a subset of the material on the "Bacterial
Culture" page, above.
Laboratory
Bacterial
Toxins
Many
types of bacteria produce toxins. These excreted protein molecules act in
many different ways to cause damage to human tissues.
Powerpoint Slides
Bacteroides
This
group of endogenous anaerobes is gram-negative and does not form spores. They
are members of the normal human bacterial flora of mucous membranes and a
common cause of endogenous infections.
Powerpoint
Slides | Web Links
Bacteriology, Basic
An
introduction to bacterial shapes, sizes and growth patterns. The slideshow
includes information about inhibition of bacterial growth by chemical and
physical agents and antibacterial drugs.
Powerpoint
Slides | Laboratory
Blastomycosis
This
infection is classified as a mycosis. The fungal pathogen causes either
systemic or cutaneous infection, depending upon the route of exposure.
Disease is endemic to the Ohio River valley in the U.S. Powerpoint
Slides | Web
Links
Bordetella pertussis
Pertussis
is the disease caused by Bordetella pertussis and it is also known as
"whooping cough". This infection was once included in a group of
"childhood diseases", that are now reduced in incidence because of
active immunization programs in industrialized countries.
Lecture
Notes | Powerpoint
Slides
Borrelia species
Lyme
disease is caused by one prominent member of the genua Borrelia but
there are others. Borrelia burgdorferi is known for the
"bulls-eye" lesions of Lyme disease but Borrelia recurrentis causes
another disease transmitted by the bite of arthropods. Read more at the links
below.
Powerpoint
Slides | Web
Links
Botulism
This
is a food-borne disease caused by ingestion of preformed toxin produced by Clostridium
botulinum. The toxin causes flaccid paralysis because of its effects at
the presynaptic junction, where it blocks nerve impluses.
Lecture
Notes | Web
Links
Brucellosis
Brucellosis
is a zoonotic infection caused by one of four main pathogens in the genus Brucella.
Diesease is associated with exposure to the appropriate animal reservoir.
Powerpoint
Slides | Web Links
C
Campylobacter
Campylobacteriosis
is an infection caused by ingestion of contaminated foods, most commonly
chicken. The disease is a gastroenteritis.
Powerpoint
Slides | Web
Links
Candidiasis
Candida albicans is a fungal organism associated with the
normal skin surface of most humans. It causes "diaper rash" and
"dishwasher's hands" in its mild form, and more invasive forms of
infection in unique populations.
Powerpoint
Slides | Web
Links
Cestodes
The
cestodes are the tapeworms, metazoan parasites that live in the intestinal
tract. They cause mainly gastrointestinal problems, but a few, like Taenia
solium, can cause more severe disease.
Lecture
Notes | Web
Links
Childhood Diseases
The
"Childhood Diseases" are a those from a collection of fevers and
rashes that at one time were universally found in pediatric patients. Many of
these have been suppressed in the population of developed countries through
active immunization programs. Several are re-emerging as problems in
countries where parents refuse to allow their children to be vaccinated.
Lecture Notes
| Childhood Parasites | U.S. 2008 Childhood Immunization
Schedule
Chlamydia
The bacterial genus Chlamydia includes several different
species that cause infections like blinding trachoma, neonatal pneumonia,
nongonoccal urethritis and pelvic inflammatory disease. Click the links below
for information on all the species, or individual species links for details.
See: Chlamydia trachomatis
Chlamydophila pneumoniae
Chlamydophila
psittaci
Powerpoint
Slides | Web Links
Chlamydophila pneumoniae
This bacterial agent
is responsible for respiratory infections and atypical pneumonia. It
primarily affects school-aged children and most individuals will have been
infected by the time they reach adult life.
Lecture
Notes
| Web
Links
Chlamydophila psittaci
This bacterial agent
is associated with disease acquired by handling infected psittacine birds
(parrots, parakeets and other exotic birds). The patient inhales contaminated
bird feces and is impacted by a respiratory infection with fever. The
mortality rate in untreated cases is high, around 5-20%.
Powerpoint
Slides
| Web
Links
Chlamydia trachomatis and Ocular Disease
Chlamydia
trachomatis is found in several
serotypes and the eye infections it causes range from inclusion
conjunctivitis to blinding trachoma.
Powerpoint
Slides |
Web
Links
Chlamydia trachomatis and Sexually-Transmitted Infection
Chlamydia
trachomatis serotypes D through
K cause the infection known as "chlamydia", the most common
sexually transmitted infection in the U.S. The L serotypes of Chlamydia
trachomatis cause a glandular disease known as lymphogranuloma venereum.
These infections can result in scarring of the reproductive tract and
infertility.
Powerpoint
Slides |
Laboratory
Diagnosis
| Web
Links
Cholera
Vibrio cholerae is the bacterial agent responsible for the
disease known by the same name. Cholera is an ancient disease, associated
with contaminated water and affecting humans in sweeping pandemics for
millenia. Modern pandemics have been found in Asia, Africa and South America.
Powerpoint
Slides
| Web
Links
Clostridium species, general information
These anaerobic
bacteria are gram-positive, spore-formers. Information about individual
species and diseases is found at the links below.
Lecture
Notes |
Web
Links
Clostridium botulinum
The bacterial agent
responsible for the disease botulism, Clostridium botulinum is an
anaerobic organism associated with the ingestion of contaminated food. Botulism
is a classic form of toxin-induced food poisoning.
Lecture
Notes |
Web
Links
Clostridium difficle
The disease caused
by this bacterial agent is pseudomembranous ulcerative colitis. The agent is
a gram-positive, spore-forming, anaerobic organism. The diarrhea syndrome can
result when the anaerobic agent overgrows the bowel after a patient has been
treated with certain antibiotics.
Lecture
Notes |
Web
Links
Clostridium perfringens
This anaerobic
bacteria is a member of the normal gut flora for humans. Disease is caused by
deep wounds that become contaminated with the organism, and can be a
post-surgical complication.
Lecture
Notes |
Web
Links
Clostridium tetani
The disease tetanus
is caused by this bacterial agent that is another member of the
gram-positive, spore-forming anaerobes from the genus Clostridium.
Growth of the bacteria is less important than production of bacterial toxin,
so the spastic paralysis due to the toxin's action is classified as a
toxemia.
Lecture
Notes |
Web
Links
CNS Viruses
Viruses that affect
the central nervous system include the arboviruses, rabies virus, the prion
diseases (which are not actually viruses at all), and several that produce
CNS effects, but are not considered along with the viruses in this group.
Powerpoint
Slides
Coccidioidomycosis
Coccidioides immitis causes this systemic fungal respiratory
infection in endemic areas. The mycosis presents as a "flu" with
fever, cough, headaches, rash, and body aches.
Powerpoint
Slides |
Web
Links
Corynebacterium diphtheriae
Corynebacterium
diphtheriae is the infectious
agent responsible for the disease diphtheria. Childhood vaccination programs
have all but eliminated the disease in the U.S. Severe disease is associated
with the formation of a pseudomembrane that can obstruct the airways and
cause suffocation. The membrane is only produced by strains that carry a
bacteriophage virus that encodes diphtheria toxin.
Powerpoint
Slides
| Web
Links
Cryptococcosis
Cryptococcus
neoformans is the fungal agent
that causes this systemic respiratory infection. Especially associated with
pigeon droppings, persons who are at-risk for infection include cancer patients,
transplant recipients and other immunosuppressed individuals.
Powerpoint
Slides
| Web
Links
Cryptosporidium
Cryptosporidiosis is
an infection transmitted by contaminated drinking water or recreational
water. It is a parasitic disease that causes diarrhea.
Outline
Format Information
| Web
Links
D
Dermatophyte Fungi
The fungal agents
that cause skin infections but not deeper disease are collectively called the
"Dermatophytes", or those producing dermatophytic infection. The
condition is called "Tinea" and named for the area of the body
affected (tinea corporis = body fungus; tinea capitis = head infection).
Powerpoint
Slides
| Web
Links
Diagnostic Methods
The diagnosis of infection utilizes
many different types of laboratory assays and methods. These include sampling
of the agent involved followed by culture, microscopy, and identification; as
well as sampling the patient blood for evidence of serum antibodies and
elevated levels of the cells involved in fighting infection.
See:
A List of Immunological Assays
Immunodiffusion and Western Blots (immunoblot assay)
Differential White Blood Cell Count and Erythrocyte
Sedimentation Rate
Laboratory Identification of Enteric Bacteria
Lung Testing: Adventitious Lung Sounds and Chest
X-rays
Diarrhea
Diarrhea is a symptom of any number
of infections. It can be a consequence of bacterial infection, viral
infection and parasitic infections. Abdominal cramping and nausea often
accompany this malady. The links below have information about some common
gastrointestinal pathogens that cause diarrhea.
See: Cryptosporidium
Escherichia coli
Giardia lamblia
Rotavirus
Diphtheria
See also Corynebacterium diphtheriae. Before vaccines were available,
diphtheria was a respiratory disease that affected mainly children. Infection
begins with a sore throat and low-grade fever. Swelling of the lymph nodes in
the neck occurs with severe disease. Cardiac and nervous system complications
as well as airway obstruction are complications of respiratory diphtheria and
death can result in up to 10% of cases. Childhood vaccination programs have
all but eliminated the disease in the U.S.
Powerpoint
Slides | Web
Links
E
Emerging Foodborne Disease
Many types of
infection are increasing over time. Various factors contribute to this
problem including the rise in population, increase in food consumption from
prepared sources rather than in the home, and lack in inspection that
contributes to poor sanitation practices.
Powerpoint
Slides | Web
Links
Encephalitis, Arboviral
There are several
types of virus that are transmitted through the bite of arthropods. The
arboviral encephalitis viruses that are important in the U.S. include West Nile virus,
California
Encephalitis virus, the Equine Encephalitis viruses and St. Louis
Encephalitis virus. Worldwide there are many others.
Powerpoint
Slides | Web
Links
Enterobacteriacae, the Gram-Negative Enteric Bacteria
The enteric bacteria
are largely represented by the family Enterobacteriacae that includes Escherichia coli,
Salmonella, and Shigella as well as several other species that are
important agents of human disease.
Powerpoint
Slides | Laboratory | Minaturized
Systems for Culture Identification
Escherichia coli
One of the most
common bacteria in humans, E. coli is found as a normal flora organism
(it inhabits the lower gastrointestinal tract). This and other coliform
bacteria are responsible for a vast array of human infections. Of particular
concern is the strain O157:H7, a type of E. coli associated with recent
fatal outbreaks of contaminated foods.
Powerpoint
Slides | Web Links | On
the Farm
F
Fasciitis and Infection with Group A Strep
One severe type of
infection is fasciitis, or infection of the large sheets of connective tissue
known as fascia. This can be a life-threatening condition.
Case
Study
Flagella and Mechanisms of Bacterial Motility
Bacteria use a
special type of flagella to move from one place to another. In addition, some
mobilize eukaryotic cell action in order to propel themselves through the
environment in response to molecules that either attract or repell them.
Lecure
Outline
Francisella tularensis
Disease caused by this gram-negative rod is
transmitted by infected rabbits, or through the bite of a deer fly. It is
therefore categorized a zoonotic infection: Tularemia.
Powerpoint Slides | Web Links
Foodborne Infections
Foodborne disease comes in many forms and
can be caused by bacteria or their toxins that are released into foods, or
viruses. Links provided here go back to the "Emerging Foodborne
Infections" grouped above.
Comprehensive Information from the CDC
Flu
See: Influenza Virus
Haemophilus influenzae Serotype B (HIB) Disease, not to be confused with "THE
FLU".
Fungal Chemotherapy
The agents used to treat fungal infections
can cause problems for humans because our cells and those of fungal pathogens
are both eukaryotic. Selective cytotoxicity is not as good as when chemicals
are used to treat human infections caused by prokaryotes.
Powerpoint Slides | Web links
Fungal Infections, Systemic
Information for the systemic infections
caused by fungi is linked below.
See Mycosis, Systemic
Fungal Structure and Taxonomy
The fungal infections that cause problems
for humans are mainly opportunistic infections caused by organisms that are
professional saprophytes. The agents typically make their living by absorbing
nutrients from decomposing organic matter. Humans are mainly incidental
hosts.
Powerpoint Slides | Web links
Fusospirochetal Disease
Synergistic infection of the oral cavity,
especially the gingiva, by bacterial agents including Borrelia gingivalis,
Fusobacterium nucleatum, Clostridium perfringens, among other
species is known as Fusospirochetal Disease or Trench Mouth.
Powerpoint Slides
G
Gas Gangrene (Clostridium perfringens)
Lecture Notes | Web Links
Gastrointestinal Viruses
Viral infections of the gastrointestinal
tract, known as gastroenteritis or enterocolitis, can be caused by a wide
variety of viruses. Common viruses are rotavirus and the picornaviruses of
the enterovirus group. They are among the most common viral agents that cause
disease in humans.
Powerpoint Slides | Web Links
Giardia lamblia
Giardiasis is the disease caused by Giardia
lamblia, a parasite of the lower gastrointestinal tract. Chronic diarrhea
is the main symptom and the patient can have weight loss and flatulence as
additional problems.
Outline Format Information | Web Links
Gonorrhea
Gonorrhea is the disease caused by Neisseria
gonorrhoeae, a gram-negative bacterial agent that causes a number of
infections, most commonly of the reproductive tract. It is one of the
sexually transmitted pathogens.
Powerpoint Slides
Gram Negative Sepsis and Septic Shock
Gram negative bacteria are notorious
for causing septic shock, a disease condition where the immune system is
powerfully activated by the by-products of infection, in particular
lipopolysaccharide (LPS). Septic shock is the cause of death for a large
number of hospitalized patients each year, many of them elderly.
Powerpoint Slides
Group A Streptococcal Disease
Group A Strep (GAS) are the bacteria
most people think of when someone says "Strep Throat". They cause
disease ranging from pharyngitis to Scarlet Fever and flesh-eating Strep
disease.
Powerpoint Slides | Laboratory | Web Links
Group B Streptococcal Disease (GBS)
At one time in the not-too-distant
past, Group B Strep infection was a major cause of neonatal meningitis
in the U.S.
Now, an aggressive program of prenatal surveillance and for the organism and
treatment before delivery has greatly reduced these infections. Read more
about it at the links below.
Powerpoint Slides | Laboratory | Web
Links
H
Haemophilus influenzae Serotype B (HIB) Disease
In the past, respiratory infection
caused by Haemophilus influenzae Serotype B was a
significant cause of morbidity and mortality among infants in the U.S. Now, a
successful vaccination program has all but eliminated this organism as a
cause of severe disease.
Powerpoint Slides | Laboratory | Web Links
Hansen's Disease (Leprosy)
See also Mycobacterium leprae. Hansen's Disease,
another name for leprosy, is an ancient affliction of humans. Disease is
characterized by skin lesions and nerve deterioration. Although treatable
with antibiotics, social stigma is a continuing problem and confinement of
patients in specialized facilities known as sanitoriums was once common.
Fortunately, the worldwide incidence of leprosy is declining and certain
endemics areas have over 90% of active cases.
Go to Mycobacterium
leprae
Helicobacter pylori This bacterial agent
is associated with gastric ulcers and the potential for gastric cancer due to
chronic infection. It is an important pathogen in terms of its widespread
distribution, and is increasingly recognized as a contributing factor in
chronic gastritis of many kinds.
Powerpoint Slides | Web Links
Hepatitis Viruses
Hepatitis is a disease of the liver.
It is characterized by elevations in liver enzymes and signs like jaundice
(yellow skin) and icterus (yellow sclera of the eye). It can be caused by a
number of viral agents and even a few bacteria, but the main viruses are the
Hepatitis viruses listed below.
Powerpoint Slides | Web Links
Histoplasmosis
Histoplasma
capsulatum is the fungal agent that causes
histoplasmosis. It is a systemic agent, a dimorphic fungus that causes an
initial respiratory infection and sometimes cutaneous infections can result
from exposure. The endemic region for the U.S.
is the Ohio and Mississippi
River valley areas.
Powerpoint Slides | Web Links
Host-Parasite Relationships
The relationship between a human and the
microbes that occupy various niches is explored in this series of slides. A
delicate balance is maintained that ensures the health of the human host.
When injury or concurrent illness upsets the normal status quo, the
micro-organisms gain the upper hand, and infectious disease results.
Lecture Notes | Web Links
I
Influenza Viruses
Seasonal influenza is caused by a segmented
RNA virus that is constantly changing, the influenza A virus. In any given
year, the general popuation can be exposed to a strain of influenza virus to
which very few people has immunity. There are many factors that contribute to
the concerns caused by this common infectious agent. Influenza B and
influenza C viruses are also included.
Powerpoint Slides | Web
Links
Intracellular Pathogens and Th1 versus Th2 Response
Many of the pathogens that are engulfed by
macrophages have two patterns for infection depending upon the immune status
of the host. Patients with intact cell-mediated immunity generally have
milder, more contained disease presentations. Immunocompromised patients have
special problems due to the nature of the immune response.
L |
