715
We are convinced that more examples will be forthcoming as scientists realise and
look for co-infections during diagnostic investigations.
Taxonomy and Diagnosis
With the current focus on biodiversity, there has been a resurgence of interest in
taxonomy although the rush to name new taxa based around the study of single
isolates is of questionable value to science. Nevertheless, the current reliance on
molecular methods, and notably sequencing of the 16S rRNA gene is likely to continue; the approach has certainly improved the standard of disease diagnoses with
bacterial identifi cation losing some of its subjectivity. With the development of
methods such as LAMP, molecular biology has become more user friendly, and may
now be undertaken in routine rather than specialized laboratories. The availability
of more rapid, reliable and cheaper molecular techniques will further improve diagnostic potential. In the meantime, serology offers rapid, fi eld-based diagnostic systems. However, there remains the overriding issue about what a positive result
means for an ultrasensitive test especially in the absence of overt disease signs. If a
test detects background levels of a pathogen – an example would be Aer. hydrophila
which occurs naturally in the eutrophic freshwater environment and which could
easily contaminate pathological specimens – then the value for disease diagnosis is
limited.
Isolation and Selective Isolation of Pathogens
With the advance of the molecular era with its culture-independent approaches, it is
pertinent to enquire if culturing will continue to have a role in fi sh disease work. We
argue that pure cultures logged in established culture collections provide an invaluable reference tool, and are invaluable for biotechnology application. However, not
all organisms will grow in vitro; Candidatus provides a current challenge. Where
culturing is a prelude to identifi cation then clearly suitable culture systems are
needed, but there are still only a few selective isolation procedures for bacterial fi sh
pathogens.
Ecology (Epizootiology)
There has been a trend away from studying the ecology of fi sh pathogens, and in
particular determining their role/location in the aquatic environment. Work on the
NCBV state has largely ceased. This is a pity but undoubtedly refl ects the lack of
research funding opportunities.
Ecology (Epizootiology)
We are convinced that more examples will be forthcoming as scientists realise and
look for co-infections during diagnostic investigations.
Taxonomy and Diagnosis
With the current focus on biodiversity, there has been a resurgence of interest in
taxonomy although the rush to name new taxa based around the study of single
isolates is of questionable value to science. Nevertheless, the current reliance on
molecular methods, and notably sequencing of the 16S rRNA gene is likely to continue; the approach has certainly improved the standard of disease diagnoses with
bacterial identifi cation losing some of its subjectivity. With the development of
methods such as LAMP, molecular biology has become more user friendly, and may
now be undertaken in routine rather than specialized laboratories. The availability
of more rapid, reliable and cheaper molecular techniques will further improve diagnostic potential. In the meantime, serology offers rapid, fi eld-based diagnostic systems. However, there remains the overriding issue about what a positive result
means for an ultrasensitive test especially in the absence of overt disease signs. If a
test detects background levels of a pathogen – an example would be Aer. hydrophila
which occurs naturally in the eutrophic freshwater environment and which could
easily contaminate pathological specimens – then the value for disease diagnosis is
limited.
Isolation and Selective Isolation of Pathogens
With the advance of the molecular era with its culture-independent approaches, it is
pertinent to enquire if culturing will continue to have a role in fi sh disease work. We
argue that pure cultures logged in established culture collections provide an invaluable reference tool, and are invaluable for biotechnology application. However, not
all organisms will grow in vitro; Candidatus provides a current challenge. Where
culturing is a prelude to identifi cation then clearly suitable culture systems are
needed, but there are still only a few selective isolation procedures for bacterial fi sh
pathogens.
Ecology (Epizootiology)
There has been a trend away from studying the ecology of fi sh pathogens, and in
particular determining their role/location in the aquatic environment. Work on the
NCBV state has largely ceased. This is a pity but undoubtedly refl ects the lack of
research funding opportunities.
Ecology (Epizootiology)