Chlamydial infections in other animals: Invertebrates
Arthropods (Insecta, Arachnida)
Chlamydial infections of arthropods have
been described. Arthropod species that sustained experimental chlamydial growth and infectivity included ticks (Ornithodorus moubata and O. coriaceus;
Weyer, 1970), and lice (Pediculus humanus;
McKercher et al., 1980).
Chlamydial agents were also recovered from ticks and fleas in California (Eddie et al.,
1969). Chlamydia-like organisms have been observed in the hepatopancreas of the spider, Coelotes luctuosus
(Osaki, 1973); caused fatal disease in the spider Pisaura mirabilis
(Morel, 1978); and were detected in the ovaries of the spider, Segestrai senoculata
(Traciuc, 1985).
Arthropods are thought to be important vectors
of C. trachomatis in [human] trachoma [see: role
of flies in trachoma] caused by ocular serovars of C. trachomatis.
Briefly, Emerson et al., (2000) reported that the fly species Musca sorbens was likely to be the principal insect vector of trachoma infection in humans in the Gambia. M. sorbens,
a fly which feeds on eye secretions, was a more important vector than the
common house fly, M. domestica.
Molluscs
In bivalves, Harshbarger and Chang (1977)
found Chlamydia
- like agents in the digestive systems of hard clams and oysters from the Chesapeake Bay
area of the USA. Some of these organisms were shown by electron microscopy to
contain phage [see: chlamydial phages].. Similar organisms were detected in the digestive cells of
approximately 5% of mussels from the Basque coast (Cajaraville and
Angulo, 1991).
Infected digestive cells showed areas of damage. Svardh (1999) examined the prevalence of disease organisms in blue mussel populations in Denmark.
Over a one-year period, the only bacterial infection detected was Chlamydia, but
its occurrence was rare.
Amoeba
Chlamydia-like
organisms now classified in the family Parachlamydiaceae have been isolated from amoebae
(Amman et al., 1997) and include
Parachlamydia acanthamoebae BN9 and Hall's coccus. Acanthamoeba species hosting
parachlamydial strains, including Hall’s coccus have been isolated from humans in cases of humidifier fever in the U.S.A.
(Lewis et al., 1990), and from clinically normal patients in Germany. Sera from
these patients did not cross react with antigens of the Chlamydiaceae (Everett et al.,
2000).
There is evidence that parachlamydial pathogens of amoebae may be associated
with community acquired pneumonia and possibly Kawasaki
disease (Marrie et al.,
2001; see Parachlamydiaceae).
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