Phenotypic characteristics of 12 paired, Salmonella serotypes isolated from healthy and ill chickens were compared. Variables compared included antibiotic resistance profiles, production of colicins and siderophores, mannose-sensitive hemagglutination of erythrocytes, resistance to serum complement, carbon source utilization, presence and transmissibility of R plasmids, and invasiveness in primary chicken kidney cell culture. Differences were found between pairs for utilization of carbon sources, mannose-sensitive hemagglutination of erythrocytes, and invasiveness in cell culture.

Atracurium besylate, a nondepolarizing neuromuscular blocking agent, was administered to 24 isoflurane-anesthetized domestic chickens. Birds were randomly assigned to 4 groups, and atracurium was administered at dosage of 0.15, 0.25, 0.35 or 0.45 mg/kg of body weight. The time of onset of twitch depression, the amount of maximal twitch depression, and the duration of muscular relaxation were recorded. After return to control twitch height, atracurium was further administered to achieve > 75% twitch depression. When twitch depression reached 75% during noninduced recovery, 0.5 mg of edrophonium/kg was administered to reverse the muscle relaxation. Throughout the experimental period, cardiovascular, arterial blood gas, and acid-base variables were monitored. The effective dosage of atracurium to result in 95% twitch depression in 50% of birds, (ED95/9595) was calculated, using probit analysis, to be 0.25 mg/kg, whereas the ED95/95 the dosage of atracurium to result in 95% twitch depression in 95% of birds, was calculated by probit analysis to be 0.46 mg/kg. The total duration of action at dosage of 0.25 mg/kg was 34.5 +/- 5.8 minutes; at the highest dosage (0.45 mg/kg), total duration increased to 47.8 +/- 10.3 minutes. The return to control twitch height was greatly hastened by administration of edrophonium. Small, but statistically significant changes in heart rate and systolic blood pressure, were associated with administration of atracurium and edrophonium. These changes would not be clinically relevant. In this study, atracurium was found to be safe and reliable for induction of muscle relaxation in isoflurane anesthetized chickens.

When Salmonella typhimurium and Clostridium perfringens were tested in conventional chickens, larger numbers of S typhimurium and C perfringens adhered to Eimeria tenella-infected ceca than to uninfected ceca. In germ-free chickens, S typhimurium and C perfringens adhered to the E tenella-infected cecal mucosa more than to the uninfected cecal mucosa, but fewer Bacteroides vulgatus and Bifidobacterium thermophilum adhered to the E tenella-infected ceca than to the uninfected ceca. Many bacteria adhered to the lesions caused by E tenella as observed by scanning electron microscopy. On the basis of our findings, we suggest that infection with E tenella upsets the balance of competitive adherence of bacteria, allowing more colonization of S typhimurium and C perfringens.

An inactivated oil-based Newcastle disease vaccine was prepared using Mukteswar vaccine strain. The virus was propagated in 10-day old embryonating eggs and inactivated by 0.12% formalin for 48 hours at 37 degree C. The vaccine was formulated with 1 part antigen (aqueous phase) and 4 parts oil base. The oil base contained Tween-80 1%, Arlacel-A 10% and Mineral oil 89%. The stability of the vaccine was found satisfactory after 6 months and its viscosity and injectability was fairly ideal. The antigenicity of the vaccine was determined in 16 week-old pullets. The seromonitoring of the vaccinated and the control pullets was carried out for three months post- vaccination by Haemagglutination inhibition (HI) test. Blood samples were taken at fortnightly intervals. The Geometric mean HI titre of the vaccinated pullets on the day of vaccination 15, 30, 45, 60, 75, 90, 105 and 120 days post- vaccination was 18.4, 4.9, 87.5, 192.3, 257.6, 111.4, 91.7, 63.9 and 30.0. However, in non-vaccinated control pullets it was found to be 18.4, 3.7, 3.7, 4.3, 3.8, 4.0, 3.5, 2.8 and 2.3 respectively. The inactivated oil-based vaccine induced a marked antibody response which continued upto three months.

Different selective culture media were evaluated for isolation of Aeromonas spp. from 120 poultry meat samples. The recovery ofAeromonas isolates was highest fromAmpicillin DextrinAgar (89.39%), followed by Aeromonas Starch DNAse agar (68.18 %) andAeromonas isolation media (18.18 %).

In the study, 348 bacterial isolates comprising of Escherichia coli (100), Klebsiella aerogens (45), Proteus mirablis (35), Peudomonas aerogens (20), Staphylococcus sp. (78), Streptococcus sp. (13), Bacillus sp. (57) were isolated from egg shell and egg contents of 150 egg samples collected from local market in Patna (Bihar). The isolates were subjected to antibiogram. This study demonstrated that egg from organized farm microbial contamination than unorganized poultry farm reflecting the effect of environment, storage and transportation on microbial quality of eggs.

To establish vaccine strains of H5 and H7 influenza viruses, A/duck/Hokkaido/Vac-1/04 (H5N1) [Vac-1/04 (H5N1)], A/duck/Hokhaido/Vac-3/07 (H5N1) [Vac-3/07 (H5N1)], and A/duck/Hokkaido/Vac-2/04 (H7N7) [Vac-2/04 (H7N7)] were generated from non-pathogenic avian influenza viruses isolated from migratory ducks. Vac-1/04 (H5N1) and Vac-3/07 (H5N1) were generated by genetic reassortment between H5N2 or H5N3 virus as an HA gene provider and H7N1 or H6N1 virus as an NA gene provider. Vac-2/04 (H7N7) was a genetic reassortant obtained using H7N7 and H9N2 viruses to give high growth character of the H9N2 virus in chicken embryonated eggs. The results of sequence analyses and experimental infections revealed that these H5N1 and H7N7 reassortant viruses were non-pathogenic in chickens and embryos, and had good growth potential in embryonated eggs. These viruses should be useful to develop vaccines against H5 and H7 highly pathogenic avian influenza viruses.

This study was carried out for investigation of an outbreak in Karachi. A disease outbreak in poultry was reported during April, 2000 in Karachi. The main symptoms included respiratory distress, sneezing and gasping. Autopsy of dead birds showed tracheitis, air-sacculitis and involvement of lungs. The morbid material was collected for processing in the laboratory. During the investigation for isolation of pathogenic bacteria or virus, Ornithobacterium rhinotracheale was isolated on 5% sheep blood agar plates in an atmosphere containing 5-10% CO2 at 37 degree C and identified through biochemical and fermentation tests. A Lasota like virus was also isolated from the same material which showed HA activity but was found negative to Avian Influenza virus against known Avian Influenza serum. The isolated virus was sent to Central Veterinary Laboratory, Weybridge, U.K. which confirmed it to be Lasota virus having comparatively high Intracerebral Pathogenicity Index (ICPI) as 0.90. Attempts for the transmission of the disease in susceptible healthy broiler chicks was successful through aerosol route using combination of inoculum of the isolated bacteria and virus. On post-mortem of infected birds air- sacculitis, tracheitis and unilateral pneumonia were noticed. Again ORT and NDV were isolated from the material harvested from these chicks. According to the observations of these experiments, it was concluded that the isolated ORT had a triggering effect on Lasota virus or vice versa. The environmental temperature and other stress factors might have aggravated the disease problem.