Al-Qadisiyah Journal of Veterinary Medicine Sciences

Abstract Methicillin-resistant Staphylococcus aureus (MRSA) is associated with a significant rate of skin and other systemic infections throughout the world in both humans and animals. This study was conducted to evaluate the in vitro and in vivo antibacterial activity of commercial coconut oil against MRSA. Clinical isolates of MRSA were obtained from AL- sadder Teaching hospital /Basra / Iraq and were identified and confirmed by standard methods. The in vitro antibacterial activity of coconut oil was studied by the disc diffusion method which has shown strong suppressive activity on MRSA. Full strength coconut oil exhibited a better zone of inhibition around MRSA in comparison to diluted preparations. For in vivo activity, 24 adult rabbits were allocated to test MRSA-induced skin infection. Four sets of experimental animals each consisting of 6 rabbits were grouped. Multiple regions in each animal in all groups were inoculated with 0.1 ml of MSRA at a concentration of 1.5 x108 CFU/ml. Groups 1, 2, and 3 were additionally treated through injection in the areas of bacterial inoculation with coconut oil, vancomycin antibiotic, and normal saline respectively. Group 4 was left without any additional treatment. Viable bacterial count in the tested skin was measured on two occasions in all animals (24 and 48 hours from the experimental period). Compared to the first 24 hours, the results after 48 hours showed a significant reduction in the viable bacterial count following coconut and vancomycin treatment in comparison to those rabbits treated with normal saline or not treated at all (P-value < 0.05). Coconut oil treatment produced an 11/2 folds reduction in the viable bacterial count with mild visible skin reaction which was comparable to the effect of vancomycin. The current study concluded that the in vivo and in vitro results show that concentrated coconut oil is active against MRSA, making it a possible alternative to some of the antimicrobial agents to which these bacteria are resistant.

 

Abstract This study aimed to compare the efficiency of conventional microbiological, Miniaturizekit GP24 and molecular technique by using PCR of nuc gene in the identification of S. aureus.Also to evaluate the efficiency of the tube coagulase and DNase activity tests. 104 of suspected S.aureus was isolated from different cattle samples, (68.3%) and (75%) were positive forcoagulase and DNase tests, respectively. The sensitivity and specificity of coagulase andDNase were 92.5%, 75.7% and 79.1% , 32.4% respectively. The identification rate of S.aureus by GP24 kit and PCR detection using nuc gene was 68.26% and 64.42% respectively.Out of 104(31.7%) of isolates were identified as coagulase-negative staphylococci by usingGP24 kit. Antimicrobials susceptibility assays of 67 S. aureus isolates revealed that, theThe highest resistance rates were against penicillin (97%) followed by tetracycline (25.4%).While all isolates were found to be highly sensitive toward Imipenem, vancomycin, andchloramphenicol (100%) for each. In conclusion, the coagulase and conventionalmicrobiological techniques have more reliable results in comparison with the DNase test forthe identification of S. aureus. On other hand, the results of the GP24 kit and coagulase tube testwere similar in sensitivity and specificity.

 

Abstract Bacteriophages, recovered from sewage samples target E. coli O157:H7, were tested for their biokinetic and morphological characteristics. Bacterial lysis profile of isolated phages was performed using Escherichia coli O157:H7 (NCTC) 12900 as host bacterial cell. Morphological characteristics of phages were visualized by transmission electron microscopy. The multiplicity of infection (MOI) and biokinetic properties, particularly adsorption rate, rise period, latent period, and burst size were also calculated. Electron microscopy revealed that the isolated phages P1and P3 belong to the Siphoviridae family while the P4 phage belongs to Myoviridae; similar to other E. coli O157:H7-specific phages previously isolated. MOI of P1 was 0.01, while P3 and P4 were 0.1 phage/bacterium. These typical MOI yielding the higher titer of phage were used in the next phage tests. The adsorption curve of the P1 phage was reached a 100% adsorption rate after 25 min of host exposure. Whereas P3 and P4 were taken 35 and 30 minutes, respectively to achieve the same adsorption rate. An implication of this is used in efficient biocontrol strategies for elimination of this bacterial pathogen from their reservoirs (cattle) as well as in the food industry.