Antibacterial effect of origanum vulgare and associated haematological and serum biochemical changes in chickens

الملخص EN

The current study of discovering new antimicrobial compounds in all fields of microbial control has stimulated research regarding the antimicrobial properties of plant compounds.

The watery oregano extract was investigated for its antimicrobial activity both in vitro and in vivo.

The in vitro study was carried out to estimate the antibacterial activity of watery oregano extract against E.

coli, Pseudomonas vulgarius, Enterobacter aerogenes, Salmonella species and Staphylococcus aureus isolated from 60 fecal samples of diseased and (liver, intestine, spleen and kidney) of 25 freshly dead broilers collected during an outbreak in small private poultry farm in Ismailia.

The obtained results indicated that watery oregano extract was effective against all isolated tested organisms.

The in vivo study was established to investigate its efficacy against experimentally induced colibacillosis in broiler chicks.

This study was carried on 120 apparently healthy un sexed one day-old broiler (Lohman) chicks.

At 15 th day, they were randomly allocated into main equal 6 groups (of 20 chicks each).

The 1st group was non infected non treated, the 2nd was non infected oregano extract treated, the 3rd was E.

coli experimentally infected non treated, the 4th was E.

coli experimentally infected and oregano extract treated, the 5th was E.

coli experimentally infected ciprofloxacin treated and the 6th was E.

coli experimentally infected oregano extract and ciprofloxacin treated.

All treatments given orally in drinking water, started 48 hour pos infection and continued for 5 consecutive days.

At 2nd, 9th, and 16th day post cessation of treatment, 5 birds per group were slaughtered for blood, serum (for some hematological and biochemical studies) and tissue samples (bacteriological reisolation).

The obtained findings displayed that, the mortalities were reduced from 25 % in infected non medicated group to 15 % (G : 4) and zero in (G : 5) and(G : 6 %) respectively.

All infected treated groups showed a greater reduction in clinical symptoms and postmortem lesions severity, especially in groups (G : 5) and (G : 6).

The hematological findings revealed an increase in lymphocyte count in (G : 2), (G : 4) and (G : 6).

The biochemical study displayed that treatment of infected groups watery oregano extract, ciprofloxacin or both in combination induced an improvement in both liver and kidney functions as compared to infected unmedicated group.

In conclusion our results confirm the antimicrobial potential watery oregano extract both in vitro against all isolated tested pathogenic microorganisms in this study and in vivo against experimentally induced colibacillosis in broilers.

Additionally, our findings support the use of watery oregano extract in combination with known antibacterial drugs to enhance the immunity and reduce incidence of bacterial resistance.

However, further research studies are still needed to verify its antimicrobial effectiveness and to evaluate its protection against pathogens as well as to investigate its mechanism of action.

Moreover, the bioassay-guided fractionation procedure to characterize and isolate the antimicrobial constituents is needed.