Immune Response in Broiler Chickens

Abstract: In this experiment, the efficacy of antibiotic (oxyteracycline); Nutrilac ® as acidifier , lactiflora ® plus as probiotics mixtures) were compared against E coli O78 infection and immune response to routine vaccination (Newcastle disease (ND) and Infectious Broncitis virus (IB) and inactivated avian influenza (AI) vaccine) in broiler chickens. A total of 250, 1 Day-old Arbor Acers Broiler chicks were divided into 5 equal groups(1-5) 50 chicks per each) group 1 were kept as blank control. Chicks of group 2 were infected orally with 0.5ml of E coli O78 containing 1 x 10 4 viable organism /ml in phosphate buffered saline (PBS)and kept as infected control . Chicks of group 3 were received Nutrilac ® in water (3ml/liter).Chicks of group 4 were received lactiflora ® in feed (1 g/kg.). Chicks of group 5 were received Oxytetracyclin 20% in feed (1g/kg.) At 12 days of age chickens of groups 3-5 were orally inoculated with o.4 ml of phosphate buffered saline (PBS) containing 1 x 10 4 viable oorganism /ml of E coli (O78) by the same does of group 2. Our results showed the, mortality was highest in groups infected with E.coli (17 bird)followed by those receive , lactiflora ® plus and oxytetracyclin (6 bird/ group) then the lowest were both negative control and Nutrilac (5 bird) while weight gain in all chicken groups the Highest weight gain was those of group receiving Nutrilac ® (605) followed by group receive lactiflora ® plus(600)then group receive oxytetracyclin(583) and negative control (541) .lowest weight gain was those receive E.coli. The immune response to routine vaccination against live Newcastle disease virus (NDV) vaccine ; Infectious Bronchitis virus ( IB ) vaccine and inactivated Avian Influenza vaccine (AI) in the same chickens groups was revealed highest titer with Lactiflore plus followed by Nutrilac then oxytetracyclin then blank control . lowest immune response was showed in infected control group. Histopathological examination for second group reveald that liver central and portal veins were moderately to markedly dilated and congested in almost all samples. Changes in the hepatic parenchyma varied from diffuse and marked vascular degeneration in which the nucleui were either pyknotic or karyolysis . Hepatic necrosis which occurs either in the form of minutes sporadic necrotic foci , or variable sized multifocal areas of necrosis infiltrated with mononuclear cells were seen also . In some cases large area of hepatic necrosis were seen. The hepatocytes in the necrotic area either disappeared or showed pyknotic nucli and or showed large vesicular nuclei with peripheral chromatine .intestine showing diffused degeneration of the mucosa and desquamation of the epithelial cells that accumulate in the lumen with hyalinization, some field showing necrosed and descumated .epithelials ,and heavily mononuclear cells infilterated L.propria and congested submucosa. In conclusion It could be concluded that probiotic and acidifier has great value on poultry production as it act as growth promoter either by enhancing digestibility or competitive inhibition of colonization of pathogenic bacteria which destruct intestinal wall and produce toxins . Also results were showed those probiotics and acidifier are of positive value in immune response for vaccination

An alternative approach for evaluating the phenotypic virulence factors of pathogenic Escherichia coli

Escherichia coli is a recognized zoonotic food-borne pathogen; however, the use of polymerase chain reaction (PCR) in the underdeveloped countries to differentiate pathogenic from non-pathogenic E. coli is a problematic issue. Our grail was to assess the phenotypic virulence markers motility, hemolysin, congo red agar, embryo lethality assay and serum resistance for pathogenic E. coli (PEC) correlated to PCR tests which is currently used world-wide to evaluate the PEC. The 448 strains of Escherichia coli that were isolated from different sources, were characterized for phenotypic virulence factors such as motility, hemolysin, Congo red binding, Embryo Lethality assay (ELA) and serum resistance, as well as antibiotic susceptibility using disc diffusion method to 23 antibiotics. Results exhibited 100% motility and Congo red binding, 97.1% for hemolysin production and 90.2% in the ELA. As a result, we were able to hypothetically conclude that the aforementioned virulence markers are plain, straightforward, economical, rapid, more dynamic, uncomplicated methodology, duplicatable and cost next to nothing when compared to the molecular PCR. Their implementation in a diagnostic microbiology laboratory for vetting is a rewarding task in the underdeveloped countries. It augments endeavors to minimize the use of PCR in our investigations especially during epidemiological and outbreak investigations of PEC