Tag Archives: Histology

Damage Caused By Spoilage Bacteria to the Structure of Cattle Hides and Sheep Skins (Published)

Recently greater attention has been given to hides and skins because of the added value of processing them into leather and leather products. The study aimed to isolate and identify aerobic bacteria associated with damage to raw cattle hides and sheep/goat skins in Sudan. Probably due to poor hygiene and poor conditions in the slaughterhouses a total of 414 organisms were isolated (379 Gram- positive and 35 Gram- negative bacteria) from fresh and washed hides and skins in the slaughterhouse, salted and dried hides and skins in warehouses where these was a delay in curing and the absence of bactericides. Other bacterial species were isolated from raw hides and skins which were delivered without treatment to the tannery. Staphylococcus spp., Micrococcus spp., Corynebacterium spp., Bacillus spp., Escherichia coli and Pseudomonas spp. were the predominant microorganisms isolated. Histological examination of the putrefied areas showed that the epidermis became thin without cellular structure and appeared ribbon-like and detached from the dermis whilst the dermis became loose. The bacterial damage was clear in raw hides and skins delivered without treatment and had lesions of putrefaction with St. equorum, St. gallinarum, Dermacoccus nishinomiyaenesis, Gardnerella vaginalis being isolated from putrefied hides and skins for the first time. Significance and impact. The bacterial activity affected skins and hides structures. The epidermis and dermis layers, which are valuable tissues in the leather industry and determine the quality of the leather were severely affected.

Keywords: Bacteria, Hides, Histology, Putrefaction, Skins

HISTOLOGICAL BASED BIOMONITORING: A BASELINE ECOTOXICOLOGICAL EVALUATION OF NEW-CALABAR RIVER USING CHRYSICHTHYS NIGRODIGITATUS. (Published)

The aim of this study was to evaluate the impact of environmental contaminants on gross anatomy (external and internal) and histopathologic biomarkers in liver, kidney and gills of African Silver Catfish (Chrysichthys Nigrodigitatus) collected from New Calabar River (NCR) in comparison to a reference site (African Aquaculture Centre, ARAC). NCR was chosen for this study because of its reported elevated levels of toxicants. For this study, chemical monitoring and bio-monitoring assessments were carried out in three sampling stations (Choba, Ogbogoro and Iwofe) of NCR. The chemical assessment involved EWQI assessment, sediment quality analysis, and heavy metals and PAH assessment. The histological bio-monitoring assessment involves the sampling of twenty table-sized fish harvested from the wild – the Choba station of NCR, which were compared with ten table-sized fishes of the same specie harvested from an aqua-cultured centre, ARAC, which has a controlled water quality system. EWQI was marginal, Sediment analysis showed slightly elevated level of PAH, Fish health Assessment Index (HAI) and fish biometric (CF) were worse in fishes harvested from NCR. Histopathological assessment was done in a qualitative and semi-quantitative scenario and fishes from NCR shows worse results as compared to those from ARAC. The qualitative assessment of target organs show alterations of target, which includes: Neurotic foci, vacuolation, melano-macrophageal centre and fatty changes in liver; intercellular haemorrage, intestinal oedema and melano-macrophageal centre in kidney and; telangiecstasia, epithelial lifting and hyperplasia in gills. Semi-quantitative histological assessment showed that NCR and ARAC had fish index values of 31.1 and 3.6 respectively. Following Man Whitney Test statistical analysis, significant differences (p<0.05) were noted between NCR and ARAC.

Keywords: Ecotoxicology, Histology, biomarker, biomonitoring