Abstract: In the immunologic sense, clinical infection is a state
of failure of the immune system to combat the pathogenic weapon of
the bacteria invading the host. A motile gram negative vibroid
organism associated with marked mono and poly nuclear cell
responses was traced during the examination of a clinical material
from an infected common carp Cyprinus carpio. On primary plate
culture, growth was shown to be pure, dense population of an
Aeromonas-like colony morphotype. The pure isolate was found to
be; Aerobic, facultatively anaerobic, non-halophilic, grew at 0C, and
37C, oxidase positive utilizes glucose through fermentative pathway,
resist 0/129 and novobiocin, produces alanine and lysine
decarboxylases but non-producing ornithine dehydrolases. Tests for
the in vitro determinants of pathogenicity has shown to be; Betahaemolytic
onto blood agar, gelatinase, casienase and amylase
producer. Three in vivo determinants of pathogenicity were tested as,
the lethal dose fifty, the pathogenesis and pathogenicity. It was
evident that 0.1 milliliter of the causal bacterial cell suspension of a
density 1 x 107 CFU/ml injected intramuscularly into an average of
100gms fish toke five days incubation period, then at the day six
morbidity and mortality were initiated. LD50 was recorded at the day
12 post-infection. Use of an LD50 doses to study the pathogenicity,
reveals mononuclear and polynuclear cell responses, on examining
the stained direct films of the clinical materials from the
experimentally infected fish. Re-isolation tests confirm that the reisolant
is same. The course of the infection in natural case was shown
manifestation of; skin ulceration, haemorrhage and descaling. On
evisceration, the internal organs were shown; congestion in the
intestines, spleen and, air sacs. The induced infection showed a
milder form of these manifestations. The grading of the virulence of
this organism was virulent causing chronic course of infections as
indicated from the pathogenesis and pathogenicity studies. Thus the
infectious bacteria were consistent with Aeromonas hydrophila, and
the infection was chronic.
Abstract: Removal of PCP by a system combining
biodegradation by biofilm and adsorption was investigated here.
Three studies were conducted employing batch tests, sequencing
batch reactor (SBR) and continuous biofilm activated carbon
column reactor (BACCOR). The combination of biofilm-GAC
batch process removed about 30% more PCP than GAC adsorption
alone. For the SBR processes, both the suspended and attached
biomass could remove more than 90% of the PCP after
acclimatisation. BACCOR was able to remove more than 98% of
PCP-Na at concentrations ranging from 10 to 100 mg/L, at empty
bed contact time (EBCT) ranging from 0.75 to 4 hours. Pure and
mixed cultures from BACCOR were tested for use of PCP as sole
carbon and energy source under aerobic conditions. The isolates
were able to degrade up to 42% of PCP under aerobic conditions in
pure cultures. However, mixed cultures were found able to degrade
more than 99% PCP indicating interdependence of species.