Acute Toxicity and Histopathological Changes in Gill and Liver of Catfish (Clarias Gariepinus) Juvenile Exposed to 2, 4-D Amine (Herbex D Sl®)

The acute toxicity and histopathological changes in the gill and liver of Clarias gariepinus juvenile exposed to Herbex-D SL ®, a herbicide containing 720g/l of 2, 4-D amine were investigated. In a static renewal bioassay, the fish were exposed to 0.00, 1.40, 1.44, 1.48 and 1.52mg/l of 2, 4-D amine. The 96 hours lethal concentration (LC50) of 2, 4-D amine to juvenile of Clarias gariepinus was 2g/l. The fish exposed to 2, 4-D amine showed toxicological signs of erratic swimming, loss of reflexes and lethargy. Histopathological changes in the gill architecture were characterized by lifting of epithelia layer, vacuolization, inter-lamella hyperplasia and mild desquamation of the epithelia lining. There was an evidence of advancing phase of hepatic necrosis in the liver of fish exposed to 2, 4-D amine. 2, 4-D amine is highly toxic and its use in or near aquatic environment should be monitored. Key words: 2,4- D amine (Herbex D SL®), Clarias gariepinus, Acute toxicity, Histopathology

Environmental Bacteria Associated With an Institutional Rabbit House

A bacteriological investigation of microorganisms of public health importance associated with rabbit houses was undertaken to determine the occurrence of bacteria in rabbit house in Ibadan. A total of 144 swab samples were collected from which 160 bacterial isolates were recovered. E. coli, (20%) showed the highest occurrence, followed in descending order by Staphylococcus aureus (12.5%), Proteus vulgaris (12.5%), Bacillus cereus (12.5%), Bacillus subtilis (10%), Streptococcus faecalis (10%), Bacillus firmus (7.5%), Proteus morganii (5%), Pseudomonas aureginosa (I2.5%), Streptococcus pyogenes (2.5%), Micrococcus species (2.5%)and Klebsiella species(2.5%). All the 20 (12.5%) staphylococcal isolates were coagulase-positive using tube coagulase test with human plasma. Similar strains of bacteria encountered in this investigation have been incriminated in disease outbreaks in rabbits with losses in terms of meat meant for human consumption and are therefore of public health importance. There is the need for regular microbiological surveillance to protect our growing rabbitaries and the rabbit models in biomedical research since these latent organisms may produce clinical conditions when the rabbits are exposed to stress conditions. Above all the importance of good hygiene and management in rabbitaries cannot be overemphasized to prevent avoidable outbreaks