Species of bacterium
Bartonella bacilliformis
is a
bacterium
,
Gram negative
aerobic
,
pleomorphic
,
flagellated
, motile,
coccobacillary
, 2?3 μm long, 0.2?0.5 μm wide, and a facultative
intracellular bacterium
.
History
[
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]
The bacterium was discovered by
Peruvian
microbiologist
Alberto Barton
in 1905, but it was not published until 1909. Barton originally identified them as endoglobular structures, which actually were the bacteria living inside
red blood cells
. Until 1993, the
genus
Bartonella
contained only one species; there are now more than 23 identified species, all of them within family Bartonellaceae.
[1]
Epidemiology
[
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]
Bartonella bacilliformis
is found only in
Peru
,
Ecuador
, and
Colombia
and some areas of south Florida .
[2]
It is
endemic
in some areas of
Peru
, with outbreaks of the disease occurring in new epidemic areas.
[3]
The bacterium is transmitted by
sandflies
of the genus
Lutzomyia
.
Microbiology
[
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]
For its isolation, special cultures are required, containing complemental soy
agar
,
proteases
,
peptones
, some essential
amino acids
, and blood. The optimum growing temperature is 19?29 °C. Colonies grow in Columbia blood agar supplemented with 10%
defibrinated
bovine blood incubated at 19?25 °C for 2 weeks.
Pathophysiology
[
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]
As the
sandflies
bite, the bacteria are inoculated into the capillaries, where in a variable period of time (around 21 days) it invades the red blood cells producing severe intravascular hemolytic anemia (acute phase of Carrion's disease).
[4]
This phase is a potentially life-threatening infection, and it is associated with high
fever
, anemia, and transient
immunosuppression
. The acute phase typically lasts two to four weeks.
Peripheral blood smears
show
anisomacrocytosis
with many coccobacilli adhered to red blood cells.
Thrombocytopenia
is also seen and can be severe. Neurological involvement is sometimes seen (neurobartonellosis) and the
prognosis
in this case is poor. The most feared complications are super-infections, mainly by
enterobacteria
such as
Salmonella
, or parasites such as
Toxoplasma gondii
and
Pneumocystis
.
When the bacterium invades endothelial cells, it produces the chronic manifestation of the disease known as
verruga peruana
. This phase consists of a
benign
skin eruption with raised, reddish-purple
nodules
(
angiomatous tumours
). Visualization of the bacteria is possible using
silver stain
(the
Warthin?Starry method
) on biopsies.
Disease
[
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]
Bartonella bacilliformis
is the etiologic agent of
Carrion's disease
or Oroya fever (acute phase of infection), and
verruga peruana
or
Peruvian wart
(chronic phase of infection). The acute phase of the disease is a life-threatening disease characterized by massive invasion of
Bartonella
to human red blood cells and consequently acute
hemolysis
and fever. If the infection is not treated, the case fatality rate is 40 to 85%
[5]
Patients in this phase of the infection can be complicated by overwhelming infections, primarily by enterobacteria (
Salmonella
spp) and parasites (
Toxoplasma gondii
,
Pneumocystis jirovecii
).
The chronic phase is characterized by benign eruptive lesions that are
pruritic
and bleeding, and other symptoms like
malaise
and
osteoarticular pain
.
[2]
Bartonella can be isolated from blood cultures and secretion of the lesions in people from endemic areas.
[6]
Treatment
[
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]
Before the
antibiotic
era, the only treatment for the acute phase was blood transfusion, but the effectiveness of this treatment was poor and the mortality rate was high.
[7]
References
[
edit
]
- ^
Zeaiter Z, Liang Z, Raoult D (2002).
"Genetic classification and differentiation of Bartonella species based on comparison of partial ftsZ gene sequences"
.
J. Clin. Microbiol
.
40
(10): 3641?7.
doi
:
10.1128/JCM.40.10.3641-3647.2002
.
PMC
130884
.
PMID
12354859
.
- ^
a
b
Maguina C, Garcia PJ, Gotuzzo E, Cordero L, Spach DH (September 2001).
"Bartonellosis (Carrion's disease) in the modern era"
.
Clin. Infect. Dis
.
33
(6): 772?9.
doi
:
10.1086/322614
.
PMID
11512081
.
- ^
Maco V, Maguina C, Tirado A, Maco V, Vidal JE (2004).
"Carrion's disease (
Bartonellosis bacilliformis
) confirmed by histopathology in the High Forest of Peru"
.
Rev. Inst. Med. Trop. Sao Paulo
.
46
(3): 171?4.
doi
:
10.1590/S0036-46652004000300010
.
PMID
15286824
.
- ^
Maguina C. Bartonellosis o enfermedad de Carrion. Nuevos aspectos de una vieja enfermedad. AFA edit. Lima-Peru
- ^
Maguina C, Gotuzzo E (March 2000). "Bartonellosis. New and old".
Infect. Dis. Clin. North Am
.
14
(1): 1?22, vii.
doi
:
10.1016/S0891-5520(05)70215-4
.
PMID
10738670
.
- ^
Chamberlin J, Laughlin LW, Romero S, et al. (October 2002).
"Epidemiology of endemic
Bartonella bacilliformis
: a prospective cohort study in a Peruvian mountain valley community"
.
J. Infect. Dis
.
186
(7): 983?90.
doi
:
10.1086/344054
.
PMID
12232839
.
- ^
Schultz MG (July 1968). "A history of bartonellosis (Carrion's disease)".
Am. J. Trop. Med. Hyg
.
17
(4): 503?15.
doi
:
10.4269/ajtmh.1968.17.503
.
PMID
4876803
.
External links
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]