Six groups of adult Sprague-Dawley rats were orally administered with a variety of treatments to elucidate their cytoprotective effects. Absolute ethanol combined with HCl was used to induce gastric lesions in rats. Aqueous and ethanol extracts of Chromolaena odorata, a famous folk herb for treating skin wounds were evaluated to determine their protective effect on gastric mucosa. In this study, aqueous extract and ethanol extract of C. odorata were combined with honey. In addition, honey alone and honey combined with cimetidine were also evaluated. Rat stomachs were examined grossly and histologically. Results were expressed as inhibition percentage. The honey and aqueous extract combination showed the highest inhibition percentage (72.67%) followed by honey and ethanol extract (58.92%), honey and cimetidine (56.55%) and the lowest was honey alone (46.74%). However, there were no significant differences between the effects of aqueous and ethanol extracts of C. odorata and honey in promoting cytoprotective effects and this may be due to the small sample size. Nevertheless, these results suggest that C. odorata and honey may be beneficial in treating induced gastric mucosal injury.
Thirty-five veterinary isolates of Salmonella enteritidis were characterized by their susceptibility to 10 antimicrobial agents and by their plasmid profiles on agarose gel electrophoresis. All were susceptible to carbenicillin, chloramphenicol and nalidixic acid but 89% were resistant to tetracycline. When examined, 91% of the isolates harboured plasmids, with sizes ranging from 9.8 to 60 MDa. However, it was only possible to associate the presence of plasmids with tetracycline resistance; plasmids occurring in 90% of the tetracycline-resistant isolates. In conjugation experiments, with Escherichia coli K12 Nal(r) as recipient, the tetracycline resistance in three selected S. enteritidis isolates was observed to transfer at frequencies of 3.0×10(-3) to 1.0×10(-2)/donor cell. The concomitant transfer of a 56-MDa or 60-MDa plasmid in these three S. enteritidis isolates was also detected.
The effects of topical application of Orthosiphon stamineus leaf extract on the rate of wound healing and histology of the healed wound were assessed. Four groups of adult male Sprague Dawley rats were experimentally wounded in the posterior neck area. A thin layer of blank placebo was applied topically to wounds of Group 1 rats. Wounds of experimental animals (Group 2 and 3) were dressed with placebo containing 5% and 10% O. stamineus extract, respectively. A thin layer of Intrasite gel® was applied topically to wounds of Group 4 animals as reference. Macroscopically, wounds dressed with placebo containing 5% (healed on day 14.50 ± 0.43) and 10% (healed on day 13.83 ± 0.21) O. stamineus extract each or Intrasite gel® (healed on day 13.13 ± 0.42) significantly accelerated the rate of wound healing compared to wounds dressed with blank placebo. Histological analysis of healed wounds confirmed the results. Wounds dressed with placebo containing 5%, 10% O.stamineus or Intrasite gel® showed markedly less scar width at wound enclosure and granulating tissue contained markedly more collagen, proliferating fibroblast with angiogenesis, and no inflammatory cells compared to wounds dressed with blank placebo. In conclusion, placebo containing 5% or 10% O. stamineus on extract-dressed wounds significantly accelerated the rate of wound healing in rats.
Strains of Aeromonas hydrophila isolates from skin lesions of the common freshwater fish, Telapia mossambica, were screened for the presence of plasmid DNA by agarose gel electrophoresis and tested for susceptibility to 10 antimicrobial agents. Of the 21 fish isolates examined, all were resistant to ampicillin and sensitive to gentamycin. Most isolates were resistant to streptomycin (57%), tetracycline (48%) and erythromycin (43%). While seven of 21 isolates harboured plasmids, with sizes ranging from 3 to 63.4 kilobase pair (kb), it was only possible to associate the presence of a plasmid with antibiotic resistance (ampicillin and tetracycline) in strain AH11. Both the plasmid and the associated antimicrobial resistance could be transferred to an Escherichia coli recipient by single-step conjugation at a frequency of 4.3 x 10(-3) transconjugants per donor cell.
Haemorrhagic septicaemia (HS) is a major disease in cattle and buffaloes, caused by certain serotypes of Pasteurella multocida, mainly B and E serotypes. Frequent HS outbreak has a major impact in many Asian countries, including Malaysia, where farmers encounter economic loss due to low milk production as well as death of their livestock. There are four types of vaccines available; broth bacterins, alum precipitated vaccine, aluminium hydroxide gel vaccine and oil adjuvant vaccine (OAV), but these vaccines can only provide short term immunity and therefore need to be administered annually. Hence, the development of a protein vaccine using recombinant antigen can be a potential candidate for the production of HS vaccine that would give longer immunity. We have successfully cloned the ABA392 gene fragment into a protein expression vector, pET-30a. The protein was expressed from our ABA392/pET30a clone and the immunogenicity of the protein has been tested on rats. This vaccine was able to trigger an immune response and therefore has the potential to be tested as suitable vaccine candidate in future studies. It is envisaged that this subunit vaccine will make a significant contribution in the management of HS among livestock in future.