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It is estimated that 95-100% of all imported fresh and saltwater fish carry the pathogen of the Mycobacterium genus and with aquarists indiscriminate use of freely available pet store antibiotics we are in effect continuing to "cook up" antibiotic resistant strains of a fish pathogen that can infect humans, which has in at least one case led to death.
"Not only are antibiotics dangerous to our future health if we create
``super-bugs'' by careless use but misdiagnosis may cause us to kill fish by treatments
that have no hope of working." - James Langhammer,
past Curator of
Fishes at the Belle Isle Aquarium in Detroit.
"The greatest possibility of evil in self-medication is the use of too-small doses, so that instead of clearing up infection the microbes are educated to resist penicillin..."
- Sir Alexander Fleming,
Discoverer of penicillin, interview with the New York Times in 1945.
"Mycobacteriosis is particularly significant among
infections transmissible from fish to human beings.
Mycobacteriosis of fish is a chronic progressive
disease spread all over the world. The disease affects marine, brackish and fresh water fish kept as in
aquacultures, as in aquariums and free nature (Wolf
and Smith, 1999). Many mycobacterial species, both
rapid and slow growing, have been isolated from
affected fish tissues (Wayne and Kubica, 1986)
However, the most frequently detected mycobac-
terial species were the following: Mycobacterium
marinum, M. fortuitum and M. chelonae. M. avium,
M. gordonae, M. abscesus, M. aurum, M. parafortuitum,
M. poriferae, and M. triplex have also been isolated
from fish (Arakawa and Fryer, 1984; Arakawa et
al., 1986; Bragg et al., 1990; Dalsgaard et al., 1992;
Tortoli et al., 1996; Teska et al., 1997; Bruno et al.,
1998; Talaat et al., 1999; Diamant et al., 2000; Lehane
and Rawlin, 2000; Herbst et al., 2001; Perez et al.,
2001; Lescenko et al., 2003).
Mycobacteriosis of aquarium fish in the Czech
Republic is one of the most commonly diagnosed
bacterial diseases (Navratil et al., 2000; Novotny
et al., 2004). Gross changes may include emaciation, ascites, exophthalmos, and keratitis, changes
in pigmentation and skin ulcerations (Wolf and
Smith, 1999).
The significance of fish mycobacteriosis as zoonosis is evident from case reports published in scientific papers. Fish have been convincing sources of
many cases of mycobacteriosis diagnosed abroad.
Ninety-nine publications dealing with the infection of 652 cases of human beings with M. marinum appeared between 1966 and 1996. Of 193 infections with known exposures, 49% were associated
with aquarium environment [Emphasis mine - rjs], 27% with injury by
aquarium fish and 9% with injury during bathing
in sea or brackish water (Jernigan and Farr, 2000).
M. marinum often infects home aquarium hobbyists.
With the expansion of aquaculture and popularity
of recreational fishing in Australia, medical prac-
titioners can expect to see more infections of this
nature. Diagnosis and treatment may be difficult,
especially in view of emerging antibiotic resistance
in fish pathogens [Emphasis mine - rjs] (Lehane and Rawlin, 2000).
Biopsy and histopathological examination should
always be performed in injured aquarists; the presence of infectious granulomas can thus be revealed.
The staining of histological specimens according
to Ziehl-Neelsen (ZN) to detect mycobacteria is
often negative as is the culture which should be
performed under conditions allowing growth of
atypical mycobacteria which usually require a low-
er in vitro culture temperature (about 25 to 30°C),
through they can also grow when the temperatures
reach about 37°C (Wayne and Kubica, 1986; Ang et
al., 2000; Bha y et al., 2000; Matlova et al., 2003). It
is recommended to use biochemical examination
or PCR detection for identification of the causative
agent (Wayne and Kubica, 1986; Dvorska et al., 2001;
Collina et al., 2002).
Combined therapy with tuberculostatic agents
and antibiotics is necessary. A combination of
claritromycin, ethambutol, and rifampin adminis-
tered for 3 to 4 months is suitable for treating skin
granulomas in the case of torpid lesions, these may
be excised (Aubry et al., 2002; Lewis et al., 2003).
Other medications used for the therapy of fish
tank granuloma are cotrimoxazol-trimethoprim
and minocycline which must be administered for
4 to 38 weeks (Ang et al., 2000)"
- L. Novotny, L. Dvoorska, A. Lorencova, V. Beran, I. Pavlik,
Fish: a potential source of bacterial pathogens
for human beings, Vet. Med. – Czech, 49, 2004 (9): 343–358
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