|Clinical bacteria for which the gram stain is not
applicable for various reasons.
" Pathogenesis: Borrelia is transmitted
by tick or louse bites. The relapsing-fever borreliae cause recurrent febrile
bacteremias separated by remissions during which the borreliae are sequestered
in tissues; each resurgence involves a change in cell surface antigens. Lyme
disease may have different manifestations at different times; recurrences and
late sequelae may appear for many years. The pathogenesis of borrelial diseases
is not understood."http://gsbs.utmb.edu/microbook/ch035.htm
"Borrelia recurrentis (louse borne) and
B hermsii and B turicatae (tick borne) cause relapsing fevers:
influenza-like febrile diseases that follow a relapsing and remitting course.
Myocarditis is a rare sequela. Borrelia burgdorferi, causes Lyme
disease, a multisystem, relapsing febrile disease with a rash and
manifestations such as arthritis, carditis, and neuritis. "
"The clinical diagnosis is confirmed by
serology and also by microscopic visualization of the organism in blood of
relapsing fever patients. ""The tick-borne relapsing fevers and Lyme disease
are zoonoses with rodents as the major reservoir; incidence and distribution
depend mainly on the biology of the tick vectors. Louseborne relapsing fever
has no animal reservoir and causes epidemics in crowded, unsanitary
populations."" Like Leptospira, Borrelia is a flexible, spiral-shaped,
gram-negative spirochete with internal flagella. Borrelia species are
differentiated primarily on the basis of vectors and DNA homology."
The CDC reports there were just under 13,000
cases of Lyme disease in the US in 1999. And a small decline to about 11,000
cases in 2000.
Bartonella sp. cause Cat scratch fever, Oroya
fever, bacillary angiomatosis, etc.
Unraveling Mysteries Associated with Cat-Scratch Disease,
Bacillary Angiomatosis, and Related Syndromes:
Image of cat scratch lesion on thumb from CDC's Public
Health Image Library: http://phil.cdc.gov/public/1269.htm
Encephalitis Associated with Cat Scratch Disease:
"Emergence of Bartonella quintana Infection among Homeless
Nomenclature of Bartonella:
Molecular Approaches to the Identification of Unculturable
Infectious Agents: http://www.cdc.gov/ncidod/eid/vol2no3/gao.htm
Persistent Infection of Pets within a Household with Three
Bartonella Species: http://www.cdc.gov/ncidod/eid/vol4no2/kordick.htm
Preventing Zoonotic Diseases in Immunocompromised Persons:
The Role of Physicians and Veterinarians:
Cat scratch disease images, Bristol Biomedical archive:
"Bartonella is a genus of aerobic gram-negative
bacilli. Four of the 10 species identified cause the majority of Bartonella
diseases in humans: Bartonella bacilliformis, B. elizabethae, B.
henselae, and B. quintana. In the United States, the most common
clinical syndrome caused by Bartonella is cat-scratch disease.
Approximately 22,000 cases are reported each year. Although a clinical profile
of cat-scratch disease was described in 1950, the primary pathogen was not
identified until 43 years later. That pathogen, formerly assigned to the genus
Rochalimaea, is now designated as B. henselae."
"Bartonella species also cause bacillary angiomatosis, an
unusual clinical syndrome involving vascular proliferative lesions of the skin
and other organs."
"Despite the name, not all patients with cat-scratch disease
have been scratched by a cat. A few have been bitten by a cat; about 30% do not
recall either scratches or bites. Just how B. henselae is transmitted
from cats to humans remains uncertain, but it may involve traumatic inoculation
of infected fleas' feces. " "Most cat-scratch disease is transmitted from cats
less than one year old, particularly kittens with fleas."http://www.hosppract.com/issues/1998/12/celout.htm
"Laboratory confirmation of the diagnosis can be provided by
indirect fluorescent antibody (IFA) testing for Bartonella. A titer greater
than 1:64 indicates infection. The IFA test screens for three Bartonella
species associated with human disease: B. henselae, B. quintana, and B.
elizabethae. It does not distinguish between them, since there is
considerable cross-reactivity between species. The IFA test is available from
the U.S. Centers for Disease Control and Prevention."
" Culture of the organism remains very difficult, in part
because culture specimens often are obtained late in the disease, when few
organisms are present. The organism is also extremely fastidious. It
requires specific culture media, usually fresh blood plates, and it must be
incubated for several weeks at 5% CO2."
Chlamydia are obligate intracellular pathogens. While many
believe chlamydial infections to be esoteric and or rare, the numbers tell a
different story. CDC reported cumulative incidence for all types of chlamydial
infections for 1999 and for 2000 at just over 500,000 cases per year.
"Diagnosis: The clinical presentation is often diagnostic;
the diagnosis may be confirmed by serology (complement fixation or
microimmunofluorescence tests) on sera and/or tears."
"Tetracycline and erythromycin are the drugs of choice.
Penicillin is not effective. Chlamydiae are obligate intracellular bacteria.
They lack several metabolic and biosynthetic pathways and depend on the host
cell for intermediates, including ATP. Chlamydiae exist as two stages: (1)
infectious particles called elementary bodies and (2) intracytoplasmic,
reproductive forms called reticulate bodies. The chlamydiae consist of three
species, C trachomatis, C psittaci, and C pneumoniae. The first two
contain many serovars based on differences in cell wall and outer membrane
proteins. Chlamydia pneumoniae contains one serovar the TWAR organism. "
"Ocular Infections: Chlamydia trachomatis causes
trachoma and inclusion conjunctivitis. Trachoma is characterized by the
development of follicles and inflamed conjunctivae. The cornea may become
cloudy and vascularized; repeated infections are a common cause of blindness.
Inclusion conjunctivitis is a milder inflammatory conjunctival infection with
"Genital Infections: Some C trachomatis strains cause
genital infections, including nongonococcal urethritis in men and acute
salpingitis and cervicitis in women. Other strains cause lymphogranuloma
venereum, a venereal disease with genital lesions and regional lymph node
"Respiratory Infections: Chlamydia psittaci usually
causes an influenzalike illness called psittacosis. Chlamydia pneumoniae
(TWAR organism) causes atypical pneumonitis in humans."
University of Bristol, UK, Bristol Biomedical Image
enter term "chlamydia." Currently ten images of chlamydia. All are very high
microorganism causes granuloma inguinale, a venereal disease with local tissue
destruction in the genital, inguinal, and perianal
""Calymmatobacterium granulomatis causes granuloma
inguinale. This infection typically is localized in the genital region. It
spreads to adjacent areas, and the regional lymph nodes also may be inflamed.
Persistent granulomatous lesions tend to ulcerate, destroying skin and
"Calymmatobacterium granulomatis is a
Gram-negative, nonmotile rod. The capsule that surrounds the bacterial cell
appears similar to that of Klebsiella. Addition of egg yolk and incubation in a
CO2 atmosphere are required for growth on artificial
"Calymmatobacterium granulomatis is normally present in the
gut flora and may be transmitted to the genital area by autoinoculation or
sexual contact. After penetrating the skin the bacteria induce an inflammatory
reaction, which may lead to destruction of the infected tissue. Within the
inflammatory foci C granulomatis is found mainly
"Microscopic evidence of intracellular Gram-negative
encapsulated rods in ulcerative skin wounds of the genitoinguinal region is
highly indicative for granuloma inguinale. Since experience with C
granulomatis is lacking in most laboratories, cultural diagnosis probably
will fail. Eventually, the yolk sac of 5-day-old chicken embryos can be
inoculated directly with the infected material." "Infection can be prevented by
cleanliness or by avoiding sexual contacts with infected persons. Antibiotics
active against intracellular bacteria, such as tetracycline or erythromycin,
are effective in treatment.http://gsbs.utmb.edu/microbook/ch016.htm
Leptospira interrogans causes leptospirosis, a
usually mild febrile illness that may result in liver or kidney failure.
Leptospira is a flexible, spiral-shaped, Gram-negative spirochete with
internal flagella. Leptospira interrogans has many serovars based
on cell surface antigens. Pathogenesis: Leptospira enters the host through
mucosa and broken skin, resulting in bacteremia. The spirochetes multiply in
organs, most commonly the central nervous system, kidneys, and liver. They are
cleared by the immune response from the blood and most tissues but persist and
multiply for some time in the kidney tubules. Infective bacteria are shed in
the urine. The mechanism of tissue damage is not known. Serum antibodies are
responsible for host resistance. Epidemiology: Leptospirosis is a worldwide
zoonosis affecting many wild and domestic animals. Humans acquire the infection
by contact with the urine of infected animals. Human-to-human transmission is
extremely rare." http://gsbs.utmb.edu/microbook/ch035.htm
"Diagnosis: Clinical diagnosis is usually confirmed by
serology. Isolation of spirochetes is possible, but it is time-consuming and
requires special media. Control: Animal vaccination and eradication of rodents
are important. Treatment with tetracycline and penicillin G is effective. No
human vaccine is available." http://gsbs.utmb.edu/microbook/ch035.htm
PHIL ID# 138 Title: Scanning electron micrograph of
Leptospira Content Provider(s): CDC/NCID/Rob Weyant Provider E-Mail: ---
Creation Date: 1998 Description: Scanning electron micrograph of Leptospira
bacteria on 0.1 µm polycarbonate filter Source Library: Photo Credit:
PHIL ID# 1619 Leptospira bacteria, FA stain of liver
impression smear. Content Provider(s): CDC/Mildred M. Galton
PHIL ID# 1346 Title: Leptospira bacteria in liver impression
smear. FA stain. Content Provider(s): CDC/Mildred Galton
Technical information on Leptospirosis:
" The Centers for Disease Control and Prevention in Atlanta,
Georgia, has preliminary evidence that the cause of acute febrile illness among
participants in the Eco-Challenge Sabah 2000 Expedition Race held in Malaysian
Borneo, August 20 to September 3, 2000, is an infection called leptospirosis."
Mycobacterium, in general, is characterized by
the presence of long chain fatty acids called glycolic acids in the cell wall.
This property accounts for the effectiveness of the Ziehl-Nielsen stain which
is used to visualize acid-fast bacilli, AFB. Acid-fast bacilli retain
carbol-fuchsin red dye after washing with decolorizer, which is an acid, an
alcohol, or both. The organisms are very slow growing inhabitants of soil with
doubling times of 18-24 hours. Culture identification and sensitivity results
take 4-8 weeks using traditional methods. Newer Bactec procedures can
take as little as 5-12 days for identification.
Tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis
and is responsible for more than three million deaths per year. More than eight
million new cases of TB are diagnosed each year (worldwide), and almost two
billion people are latently infected with the tubercle bacillus."
More specific information about M
tuberculosis from Wadsworth Medical Center,
PHIL ID# 837 Title: Histopathology of
tuberculosis, endometrium. Ziehl-Neelsen stain. Content Provider(s): CDC/Dr.
Edwin P. Ewing, Jr. Provider E-Mail: firstname.lastname@example.org Creation Date: 1993
Description: Acid-fast Mycobacterium tuberculosis bacillus is visible within
granuloma. Source Library: PHIL http://phil.cdc.gov/public/837.htm
The University of Wisconsin online Textbook
WebPath online, AFB stain of Mycobacterium
WebPath online, auramine fluorescence
microscopy of Mycobacterium tuberculosis:
The CDC reported a total of 12,517 new cases of TB in
PHIL ID# 28 Title: Histopathology of
tuberculosis, placenta Content Provider(s): CDC/Dr. Edwin P. Ewing, Jr.
Provider E-Mail: email@example.com Creation Date: 1994 Description: Histopathology
of placenta thrombus with inflammatory cells and acid-fast bacilli of
Mycobacterium tuberculosis (Ziehl-Neelsen stain). Source Library: CDC-PHIL
"A bacillus, Mycobacterium leprae, that multiplies very
slowly and mainly affects the skin, nerves, and mucous membranes. The organism
has never been grown in bacteriologic media or cell culture, but has been grown
in mouse foot pads. Incidence An estimated 500,000 new Hansen's disease cases
are identified each year, with about 300 of these occurring in the United
States. Most cases come from 55 countries where disease continues to be
endemic. In 1998, WHO listed those countries reporting the most cases as
Bangladesh, Brazil, India, Indonesia, Myanmar, and Nigeria.""Worldwide, 1-2
million persons are permanently disabled as a result of Hansen's disease.
However, persons receiving antibiotic treatment or having completed treatment
are considered free of active infection."
Other species, non-tuberculous mycobacteria;
Mycobacterium avium, Mycobacterium intracellulare,
PHIL ID# 965 Title: Mycobacterium avium-intracellulare
infection of lymph node in patient with AIDS. Ziehl-Neelsen stain. Content
Provider(s): CDC/Dr. Edwin P. Ewing, Jr. Provider E-Mail: firstname.lastname@example.org Creation
Date: 1983 Description: Histopathology of lymph node shows tremendous
numbers of acid-fast bacilli within plump histiocytes. Source Library: PHIL
WebPath online Mycobacterium tutorial:
Mycobacterium avium-intracellulareAFB stain of lymph node
The Graduate School of Biomedical Sciences,
University of Texas Medical Branch, online Textbook of Medical Microbiology,
chapter 33, Mycobacteria and Nocardia is an excellent source of information on
glycolic acids in their cell wall. The side chains of the glycolic acids in
nocardia are shorter than mycobacteria, C40 to C56 for the former vs C60 to C90
for the latter, which reduces their retention of carbol fuchsin dye on
decolorization as compared to the members of the genus Mycobacterium.
They are thus "partially" acid fast. Nocardiasp. are described in the
section on gram positive bacilli.
Rickettsia , cause Rocky Mountain spotted
fever, Tsutsugamushi fever, etc.
"The rickettsiae are a diverse collection of obligately
intracellular Gram-negative bacteria found in ticks, lice, fleas, mites,
chiggers, and mammals. They include the genera Rickettsiae,
Ehrlichia Orientia, and Coxiella, eg.,
Coxiella burnetii. These zoonotic pathogens cause infections that
disseminate in the blood to many organs.""Pathogenesis Rickettsia and Orientia
species are transmitted by the bite of infected ticks or mites or by the feces
of infected lice or fleas. From the portal of entry in the skin, rickettsiae
spread via the bloodstream to infect the endothelium and sometimes the vascular
smooth muscle cells. Rickettsia species enter their target cells, multiply by
binary fission in the cytosol, and damage heavily parasitized cells
directly.""Rickettsioses are difficult to diagnose both clinically and in the
laboratory. Cultivation requires viable eukaryotic host cells, such as
antibiotic-free cell cultures, embryonated eggs, and susceptible animals.
Confirmation of the diagnosis requires comparison of acute- and
convalescent-phase serum antibody titers."http://gsbs.utmb.edu/microbook/ch038.htm
PHIL ID# 922 Title: Rickettsia tsutsugamushi budding
from mouse peritoneal mesothelial cell. Content Provider(s): CDC/Dr. Edwin P.
Ewing, Jr. Provider E-Mail: email@example.com Creation Date: 1976 Description: The
rickettsia is covered by the host cell plasma membrane. TEM. Source Library:
PHIL ID# 926 Title: Rickettsia tsutsugamushi dividing
within the cytoplasm of a mouse peritoneal mesothelial cell. Content
Provider(s): CDC/Dr. Edwin P. Ewing, Jr. Provider E-Mail: firstname.lastname@example.org Creation
Date: 1976 Description: The rickettsia is undergoing a pinching type division
characteristic of gram-negative bacteria including rickettsias. TEM. Source
Library: PHIL http://phil.cdc.gov/public/926.htm
The Rickettsia prowazekii Genome Sequence
Sequence reveals closest relative to mitochondria.
Members of the genus Treponema cause yaws,
syphilis, endemic syphilis, pinta, etc.
"Classification of the pathogenic treponemes is based
primarily upon the clinical manifestations of the respective diseases they
cause. Treponema pallidum subsp pallidum causes venereal
syphilis; T pallidum subsp pertenue causes yaws; T
pallidum subsp endemicum causes endemic syphilis; and T
carateum causes pinta. Venereal syphilis is transmitted by sexual contact;
the other diseases are transmitted by close nonvenereal contact."
"Treponemes are highly invasive pathogens which often
disseminate relatively soon after inoculation. Evasion of host immune responses
appears to be, at least in part, due to the unique structure of the treponemal
outer membrane (i.e., its extremely low content of surface-exposed proteins).
Although treponemes lack classical lipopolysaccharide (endotoxin), they possess
abundant lipoproteins which induce inflammatory processes."
"Diagnosis relies heavily on clinical manifestations. In
addition, the finding of treponemes within exudative lesions and positive
serology aids the diagnosis."
"Penicillin treatment eradicates all stages, including
congenital infection in pregnancy"
Treponema pallidum, the causitive agent of
"Despite the availability of effective therapy (penicillin),
syphilis remains a commonly sexually transmitted disease worldwide (over
100,000 cases were reported in the United States in 1992)."http://www.wadsworth.org/databank/treponem.htmTechnically
a gram negative bacillus with a spiral morphology, it is not grown on solid
media in the laboratory, nor is it visualized by microscopy under routine
conditions. Instead it is detected by serological tests. In 1999, the CDC
reported for both primary and secondary syphilis a total of 5,460 cases
Left: cell infiltration of spirochetes in
tissue; Right: spirochetes visualized by silver staining.http://www.wadsworth.org/databank/treponem.htm