Geoscience Reference
In-Depth Information
thus involved in biogeochemical cycles and can represent a significant
part of the total number of bacteria cultivable in coastal waters (up to
40%).
In addition to their capacity for biodegradation, certain species are
pathogens for aquatic animals and humans. Numerous studies show
that these pathogens are responsible for emergent epidemics, often
related to climate change. If the rise in the temperature of marine
waters favors these pathogens, the consequences of these climatic
variations on the hosts also come into play to explain these
emergences. Thus, the whitening of coral is triggered by global
warming, which breaks these organisms down, and by
Vibrio shiloi
and
Vibrio coralliitycus
that are pathogenic for coral [ROS 05].
Intensive farming and anthropic pressure are also responsible for the
development of serious epidemics that can decimate marine farms.
This is the case with
Vibrio salmonicida
, responsible for significant
epizootics of farmed salmon [AUS 05]. Other vibrios are mollusc
pathogens, such as
Vibrio tapetis
, responsible for brown ring disease
in clams, or
Vibrio splendidus
and
Vibrio aesturianus
, responsible for
the death of oyster larvae, undoubtedly in association with a herpes
virus [PAI 04, SCH 12].
V. cholerae
is the most well known of the vibrios pathogenic for
humans and is responsible for cholera. The majority of cases of non-
choleric human vibriosis are due to
Vibrio parahaemolyticus
,
Vibrio
vulnificus
and non-choleric
V. cholerae
[PRU 05]. These three vibrios
are the subject of a detailed presentation in the following sections.
Other vibrios are implicated in non-choleric vibriosis, such as
Vibrio
alginolyticus
,
Vibrio damsela
,
Vibrio fluvialis
,
Vibrio furnissii
,
Vibrio
hollisae
,
Vibrio metschnikovii
and
Vibrio mimicus
. In all these cases,
the consumption of shellfish and seafood, raw or slightly cooked, is
the cause of gastroenteritis from vibrios; the contact of wounds with
seawater is responsible for skin infections that can evolve into
septicemia.
3.2.4.2.
Vibrio cholerae, Vibrio parahaemolyticus, Vibrio vulnificus
Cholera is a permanently endemic disease on the Indian
subcontinent and in certain African and South American countries,
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