Control of eight predominant Eimeria spp. involved in economic coccidiosis of broiler chicken by a chemically characterized essential oil

AIM

To control eight most predominant Eimeria spp. involved in the economic disease of coccidiosis in broiler chicken, by a chemically characterized essential oil of eucalyptus and peppermint.

METHODS AND RESULTS

The experimental design consisted of 160 day-old-broiler chicks, divided into four equal groups (G1 , G2 , G3 and G4 ), with 40 birds per group. Each group was divided into four equal subgroups. Birds in G1 were deprived of essential oil treatment and of Eimeria challenge. Birds in G2 were unchallenged, and administered the essential oil in drinking water at 0.69 ml kg(-1) body weight. Birds in G3 were untreated with essential oil, and each of its four subgroups was challenged at a different age (14, 21, 28 and 35 days). Birds in G4 were treated with essential oil, and challenged in the same manner as for G3 . Equal number of birds from all subgroups (n = 10) were sacrificed at the sixth day after the time allocated for each challenge. The 6 day incubation period post challenge resulted in respective mean per cent weight increase in G2 and G1 birds equivalent to 57.8 and 53.1% (P < 0.05). In addition, the essential oil improved the per cent weight increase in challenged birds (54.6%) compared to the challenged-untreated birds (18.6%) (P < 0.05). The mean feed conversion, mortality, intestinal lesion scores and oocyst counts were significantly reduced in the challenged-treated birds compared to the challenged-untreated birds (P < 0.05).

CONCLUSIONS

The results support the hypothesis of using the essential oils of eucalyptus and peppermint to control the most prevalent Eimeria spp. involved in coccidiosis of broiler chicken, helping in improvement of their production, alleviation of lesions and reduction in intestinal oocyst counts.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides information about the possibility of using this blend of essential oil as a coccidiostat for the protection of broiler chickens against the prevalent eight Eimeria spp. of coccidiosis.

Competitive exclusion against Salmonella Enteritidis in layer chickens by yoghurt microbiota: impact on egg production, protection and yolk-antibody and cholesterol levels

AIMS

This work aims at studying the impact of competitive exclusion of Salmonella serotype Enteritidis infection in layer chickens, by microbiota of fresh and dried-modified yoghurt, on egg production and weight, protection against infection, and on yolk-antibody and cholesterol levels.

METHODS AND RESULTS

Four groups of 27-week-old layer chickens were included in this study. After an initial enrofloxacin treatment, groups 1 and 2 were administered fresh or dry yoghurt (respectively) for 14 days. Groups 1, 2 and 3 were challenged intraoesophageally with Salm. Enteritidis, on the sixth day of yoghurt administration, while group 4 was left unchallenged and without yoghurt administration. No significant difference in percent infectivity of visceral organs with Salm. Enteritidis was observed between the groups. The yoghurt administered groups showed an early significant antibody response in their yolk on the seventh day postchallenge (P < 0.05) and highest egg production and weight. Finally, the egg yolk cholesterol concentration was higher in Salm. Enteritidis-challenged groups than that observed in the unchallenged group.

CONCLUSIONS

The results point to the possible involvement of yoghurt administration in immunopotentiation and improvement of egg production and weight.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings warrant further research that could improve immunity and production in layer chickens infected with Salm. Enteritidis.

Anti-Inflammatory Bioactivities in Plant Extracts

The medical ethnobotanical knowledge propagated over generations in the coastal regions of the Eastern Mediterranean, including Lebanon, is one that has built on several ancient cultures and civilizations of these regions. Recent interest in medical ethnobotany and the use of medicinal herbs in treating or preventing ailments has rejuvenated interest in folk medicine practices, especially those transcendent across generations. According to Eastern Mediterranean folk medicine practices, herbal remedies that treat many inflammation-related ailments were typically based on plant bioactive water extracts or decoctions. Studies have shown that active anti-inflammatory ingredients in water extracts include many natural chemicals such as phenols, alkaloids, glycosides, and carbohydrates. The intent of this manuscript is twofold: first, to review the literature that describes anti-inflammatory bioactivities in plant extracts of different plant genera; and second, to evaluate indigenous folk remedies used by folk doctors to treat inflammatory ailments in this region of the world. For this aim, the reported literature of five plant genera assumed to possess anti-inflammatory bioactivities and typically prescribed by folk doctors to treat inflammation-related ailments is reviewed.

Microbiological and chemical properties of litter from different chicken types and production systems

Chicken litter is produced in large quantities from all types of poultry raising activities. It is primarily used for land application, thus it is essential to analyze its properties before it is released to the environment. The objective of this study is to compare the microbiological and chemical properties of litter generated from layer and broiler chickens reared under intensive and free-range production systems. The microbiological analysis consisted of the enumeration of total bacteria, total coliforms, Staphylococcus species, Salmonella species and Clostridium perfringens. Chicken litter from layers reared under intensive and free range systems showed lower mean total bacterial count than the litter collected from chicken broilers reared under either of the two systems (P=0.0291). The litter from intensive layers had the lowest mean total coliform counts (P=0.0222) while the lowest Staphylococcus species count was observed in the litter from free-range layers (P=0.0077). The C. perfringens count was the lowest in chicken litter from intensively raised broilers and layers (P=0.0001). The chemical properties of litter from the different chicken types and production systems were compared based on determination of pH, electrical conductivity, carbon, nitrogen, phosphorus, potassium, cadmium and zinc. Litter from free-range broilers showed the highest pH value (P=0.0005); however, the electrical conductivity was higher in the litter from both intensive and free-range layers compared to the litter from both broiler production systems (P=0.0117). Chicken litter from intensive systems had higher nitrogen content than litter from free-range systems (P=0.0000). The total phosphorus was the lowest in free-range broiler litter (P=0.0001), while the total potassium was the lowest in litter from intensively managed broilers (P=0.0000). Zinc appeared higher in litter from layers compared to that from broilers (P=0.0101). The cadmium content was higher in the litter from free-range broilers and layers compared to that in the litter from intensively managed systems (P=0.0439). Staphylococcus species in the litter as well as cadmium concentrations seem to be the most critical parameters presenting risks on the environment and on human health. Based on the lowest coliform counts (an indication of water pollution), the high nutrient levels and the low cadmium values, litter from intensively managed layers appears as the most suitable for application on agricultural soils.

Avian influenza outbreak in poultry in the Lebanon and transmission to neighbouring farmers and swine

Twenty-four poultry farms in four major provinces of the Lebanon were investigated to verify the first emergence of avian influenza (AI). Both the meat chicken breeders and commercial chicken layers presented a significant average drop in egg production equivalent to 46% and 47.3%, respectively. However, the average drop in egg production in the free-range layers was only 11.1%. Flocks were confirmed as positive for AI by ELISA, clinical signs and pathological lesions. The pathogenicity, including case fatality in affected chickens, was different depending of the types of chicken and farming conditions. The average fatality rates among breeders, commercial layers, free-range layers and broilers were 2%, 2%, 1% and 35%, respectively. The majority of the randomly selected ELISA-positive serum samples collected from different farms showed H9-specific haemagglutination inhibition (HI) antibodies. The direct immunoflorescent antibody test also revealed the presence of H9 antigen in congested brains and in tracheal lesions of broilers. The virus isolated from the brains of broilers was subtype H9N2. Pigs fed with carcasses of affected chickens showed H9-specific HI antibodies at 100%. Farmers (32.3%) serving the affected chickens also revealed these antibodies in their sera.

Comparative impact of live chicken infectious anaemia virus vaccine versus natural exposure in meat chicken breeders on immunity to infectivity by CIA and inclusion body hepatitis viruses in their offspring

The immunology and histopathology and the distribution of viral antigen in infections with chicken infectious anaemia virus (CIAV) and inclusion body hepatitis virus (IBHV) were compared in the broiler offspring of CIAV-vaccinated meat chicken breeders versus those in the offspring of breeders naturally exposed to field CIAV. No significant difference in the humoral antibody level specific for CIAV was observed between 5 and 33 weeks of age in the two breeder groups (p > 0.05). The maternal humoral immunity to CIAV in the day-old offspring of the groups did not differ significantly (p > 0.05). The humoral immunity to CIAV at 40 days of age indicated an absence of clinical signs of CIAV in the broiler offspring of both groups of breeders and this was associated with mean serum thymulin levels in offspring of both groups not differing significantly at 1 or 40 days of age. Histopathological and immunofluorescence observations did not differ significantly in the offspring of either group by CIAV or IBHV.

Evaluation of 12 stabilizers in a developed attenuated Salmonella Enteritidis vaccine

The development of a stable live attenuated Salmonella Enteritidis (SE) vaccine, resisting heat stress during transportation and storage in unequipped tropical and subtropical zones of the world, is highly recommended. Twelve stabilizers were individually supplemented into a 9 ml volume of sterile distilled water resulting in concentrations of 1, 2, 3, 4 and 5%. A volume of 1 ml of attenuated live SE vaccine is added over the 9 ml of each concentration of the stabilizers. The differently stabilized SE vaccines were stressed at 55 degrees C for 48 h. The lowest percent reductions in SE cell viability by specified level of each stabilizer in ascending order were: 22.3% by 2% skim milk, 55.1% by 5% bovine serum albumin (BSA), 59.2% by 4% sorbitol, 74.4% by 3% maltose, 75% by 2% honey, 91.3% by 3% histidine, 96.9% by 1% heparin, 97.5% by 4% dextrose, 97.9% by 5% lactose, 99.4% by 5% sucrose, 99.5% by 2% gelatin, and 100% by 1-5% glycerol. In narrowing the concentration levels of skim milk to include 1.00, 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75, and 3.00%, the 2.50% was the optimum level resulting in minimal percent reduction in SE cell viability of 18.9% after exposure to the defined heat stress.

Immune response to Newcastle disease virus in broilers: a useful model for the assessment of detoxification of ervil seeds

Ervil (Vicia ervilia) seeds are produced in the Mediterranean region and used as a source of protein for cattle and poultry. The methods used to assess the toxic effects of legume seeds in the feed of poultry include the observation of one or more parameters, including abnormal signs, weight gain, feed consumption, gall bladder weight, pancreas weight, pancreas proteolytic and amylase activity, haemolysis of red blood cells, liver weight, liver glutathione level, liver and plasma lipid levels, and plasma lipid peroxide levels. The authors describe the use of quantitative determination of the immune response to Newcastle disease virus (NDV) vaccine in broilers as a model that can be used to assess different detoxification treatments of ervil seeds. Broiler chicks fed differently-treated ervil, supplemented as 25% of the diet, at one to four weeks of age and vaccinated intraocularly with live NDV vaccine at eight days of age, showed different immune responses at three weeks post vaccination. Immunosuppression with regards to NDV was apparent in the group of birds raised on untreated ervil supplement, resulting in a mean immune response (titre) of 798.5. Five of the six different treatments of ervil seeds resulted in different degrees of rectification of the immunosuppression, with some broilers reaching a mean NDV immune titre of 2070.6, similar to that obtained in control broilers raised on a basal diet with no ervil seed supplement (mean NDV immune titre of 2333.8; P > 0.05). The five successful treatments of ervil (in increasing order of rectification of immunosuppression in broilers, with mean NDV titres in parentheses) were: ground soaked dried ervil (971.6), ground autoclaved dried ervil (1223.1), soaked autoclaved dried ervil (1273.1), soaked dried ervil (1340.0), and ground-soaked autoclaved dried ervil (2070.6).

Immunopotentiation of a developed Salmonella enterica serotype enteritidis vaccine by thymulin and zinc in meat chicken breeders

The humoral immunity, spleen and thymus weight indices, lymphocyte count in the thymus cortex, and granuloma diameter at vaccination sites were assessed in four differently immunopotentiated groups of meat chicken breeders. Breeders in the first two groups were given a killed Salmonella enterica serotype Enteritidis (SE) vaccine subcutaneously at 15 and 19 weeks of age. Breeders in the third and fourth groups were left unvaccinated. Breeders in the first group were further immunopotentiated with zinc and thymulin. Each bird in the first group was given the immunopotentiators intraperitoneally in a volume of 0.1 ml at intervals of 3 days for a period of 3 weeks, starting at 15 weeks of age. At each time, each bird in the first group received thymulin (10 ng) and ZnCl2 (1 micromol/L), using a carboxymethyl cellulose carrier, totalling 90 ng thymulin and 9 micromol of ZnCl2 per bird. Each bird in the first three groups was challenged orally with 6.7 x 10(6) cfu/ml of highly virulent SE organisms, at an age of 22 weeks. The first group, which had received zinc and thymulin, had the earliest and highest humoral immune response to SE (p<0.05). This was observed at 2 and 4 weeks after the first vaccination. In addition, the first group had the highest mean thymus weight index, and the highest mean lymphocyte count in the thymus cortex. No significant difference was observed between the first two vaccinated groups in the mean granuloma diameter developed at the two vaccination sites 48 h after administration of the vaccine (p>0.05).

Infection and immunity in broiler chicken breeders vaccinated with a temperature-sensitive mutant of Mycoplasma gallisepticum and impact on performance of offspring

A comparison of infection and immunity to Mycoplasma gallisepticum (MG) in broiler chicken breeders vaccinated with a temperature-sensitive mutant of MG versus nonvaccinated chickens, and the impact on the performance of their offspring was conducted. Infection and immunity in breeders were assessed by culture and enzyme-linked immunoassay, respectively. However, performance in their offspring was assessed by studying MG infection in embryos, occurrence of infection titers to MG in relation to mortality, and feed conversion in the broilers. Five out of 10 broiler chicken breeder flocks raised on the same multiple-age farm with a long history of mycoplasmosis were vaccinated intraocularly once with a temperature-sensitive MG mutant vaccine (ts-11) at an average age of 7.5 wk; another five breeder flocks were left as unvaccinated controls exposed to field MG. The average recoveries of ts-11 organisms from tracheas and infraorbital sinuses of 41-wk-old vaccinates were 88 and 84%, respectively. No field MG organisms were recovered from vaccinates between 15 and 41 wk of age. The recovery of field MG organisms from tracheas and sinuses of nonvaccinated chickens increased to an average of 100% at 41 wk of age. A significant decrease (P < 0.05) in the average percentage of MG-seroconverted breeders occurred in ts-11-vaccinated flocks in comparison with nonvaccinated, MG-infected flocks at 15, 20, 23, 29, 32, 36, and 41 wk of age. The average infection prevalence by MG in the vitelline membrane of 7-d-old embryos produced by the five unvaccinated breeder flocks peaked at 79% when their respective hatching eggs were collected at 36 wk of breeder's age. Embryos of ts-11-vaccinated flocks had zero prevalence of MG infection at all times between 29 and 57 wk of breeder's age. Seroconversion to MG (average of 17.7%) at 42 d of age was only present in sera of 10 offspring broiler flocks of the nonvaccinated breeders. However, a lack of seroconversion to MG occurred in 10, 42-d-old offspring broiler flocks of the five ts-11-vaccinated breeder flocks. This lack was associated with a lower, better average feed-conversion ratio (2.05) (P < 0.05) and a lower average mortality percentage (5.3%) (P < 0.05) in comparison with those obtained in the offspring of the five unvaccinated, MG-infected breeder flocks. The results indicate that vaccination of broiler chicken breeders with a temperature-sensitive mutant of MG prevented infection by field MG in tracheas and infraorbital sinuses of these breeders and in the vitelline membranes of their embryos. In addition, the broiler offspring of the vaccinated breeders had a better production performance.

Macrophage recruitment and activation: a model for comparing resistance to Salmonella enteritidis in different broiler breeds

A model for comparing resistance to Salmonella Enteritidis was evaluated in different broiler breeds. The recruitment and phagocytic activity of peritoneal macrophages were assessed in three different broiler breeds (A, B and C) which are farmed world-wide. Assessment was performed after three days of intraperitoneal (i.p.) administration of 3% Sephadex G-200 (10 ml), initiated at twenty-one days of age, followed by contact with i.p. live S. Enteritidis (10 ml, 1.2 x 10(8) colony forming units/ml) for 45 min. Assessment included determination of the number of i.p. macrophages recruited, the number of i.p. phagocytized S. Enteritidis cells per macrophage, the levels of degranulated i.p. beta-glucuronidase and beta-galactosidase, and the count of surviving S. Enteritidis cells. Confirmation of the significance of the model was obtained by comparing resistance to field infection by S. Enteritidis in the three broiler breeds. The recruitment of i.p. macrophages in response to challenge with Sephadex and S. Enteritidis was significantly higher (P < 0.05) in birds of breed A (mean cumulative i.p. macrophage count, in 10 fields of microscopic slide smear magnified at x1,000, was equal to 81.7), compared to recruitment in birds of breed B (33.3) or breed C (41.2). The mean number of phagocytized S. Enteritidis cells per i.p. macrophage in birds of breed A (2.68) was significantly higher (P < 0.05) than in breed B (0.83) and insignificantly higher (P > 0.05) than in breed C (2.35). In addition, the highest level of recruitment and phagocytic activity of macrophages, in birds of breed A, was associated with a higher significant mean i.p. beta-glucuronidase activity (10,425.5 units/ml) than in breed B (3,438.2 units/ml) or breed C (3,356.94 units/ml) (P < 0.05). Moreover, birds of breed A demonstrated a higher mean i.p. beta-galactosidase activity (2.225 units/ml) than birds of breed B (0.852 units/ml) or breed C (1.852 units/ml) (P > 0.05). The higher level of recruitment and activity of i.p. macrophages and the higher rate of degranulation of i.p. enzymes in breed A were associated with a greater number of surviving i.p. S. Enteritidis cells. In response to outbreaks of S. Enteritidis in the field, the average mortality was significantly higher in flocks of breed A (3.2%) than in flocks of breed B (1.2%) or breed C (0.96%) (P < 0.05). These data provide an indication of the significance of the model in reflecting the differences in resistance of S. Enteritidis of broiler breeds reared in a farm environment.

Chronological recognition by chicken of antigenic polypeptides in Salmonella enteritidis with different plasmid profiles: relationship to infection rate

The antigenic polypeptides in Salmonella Enteritidis (SE) were chronologically recognized by the chicken immune system, using Western immunoblotting. Broiler chicks challenged at three days of age with SE strain carrying the most prevalent plasmid profile of 14.1 and about (approximately) 50 kb were bled at 17, 24, 31, 38 and 45 days of age. Pooled sera of blood collected at each age was reacted by Western immunoblotting with banded polypeptides of three predominant SE strains that acquired the following respective plasmid profiles: 14.1 kb; 14.1 and approximately 50.0 kb; and 1.8, 14.1 and approximately 50.0 kb. The immunoblots of each pooled sera collected at a specific age against the three SE strains were similar. More specifically, the early immune response at 17 days of age had antibodies recognizing only one polypeptide in the three SE strains namely, the 35.8 kDa. At 24 or 31 days of age, the acquired immunity to infection had antibodies recognizing five similar polypeptides in the three SE strains namely, the 14.4 (fimbriae protein), 21.5 (fimbriae protein), 30.5, 35.8, and 66.2 kDa. At 38 and 45 days of age, the antibodies recognized additional polypeptides namely, the 41.5 and 55.6 kDa, respectively. The recognition of the 41.5 and 55.6 kDa polypeptides at 45 days of age was associated with higher invasiveness of SE to spleens and livers (15.6%) and in higher cecal colonization (59.4%) in comparison to absence of recognition to the two polypeptides at 31 days of age associated with low infectivity to spleens (0%), livers (3.1%), and ceca (9.4%).

Emergence of Salmonella enteritidis outbreaks in broiler chickens in the Lebanon: epidemiological markers and competitive exclusion control

This study investigates the first emergence of Salmonella Enteritidis outbreaks among chickens in the Lebanon and identifies the epidemiological markers of selected recovered Enteritidis strains. In addition, the authors evaluate a competitive exclusion approach to control infection in broiler chickens by Enteritidis organisms which possess the prevalent identified markers. The basic procedure in this investigation involved recording signs and lesions in eleven broiler chicken flocks on eleven farms, and culturing livers, spleens, and caeca of ten randomly selected birds per flock for Salmonella isolation and serotyping. Furthermore, culturing for Salmonella and serotyping was attempted from the livers, spleens, caeca and oviduct swabs of ten hens in four broiler breeder flocks which provided hatching eggs for the broilers under study. The identification of epidemiological markers in recovered S. Enteritidis included the determination of drug-resistance patterns and plasmid profiling. The competitive exclusion was evaluated by spraying the microflora on day-old broilers in the hatchery, followed by a controlled oral challenge at three days of age, with 2.85 x 10(5) colony-forming units of S. Enteritidis organisms per bird. Exclusion was evaluated by culturing for S. Enteritidis in anal swabs, spleens, livers, and caeca of individual challenged birds treated with the microflora and in untreated challenged birds. A total of 112 invasive S. Enteritidis strains were recovered on eleven farms from individual organs of broiler chickens with typical signs and lesions of salmonellosis. The prevalent resistance to drugs in such strains was to furaltadone and gentamycin, a marker identified in 93 strains (83%), recovered from nine out of eleven farms. The same resistance pattern was present in S. Enteritidis strains recovered from breeders on one out of four farms. The prevalent plasmid profile in nine S. Enteritidis organisms selected randomly from a pool of 93 strains (one per each of the nine broiler farms) was 14.1 kilobases (kb) and approximately 50.0 kb, a typical pattern to that identified in S. Enteritidis organisms recovered from oviducts of breeders on one out of four breeder farms. The exclusion significantly reduced cumulative mortality in birds of up to 45 days of age by 3.93%, in comparison to that observed in untreated challenged birds (P < 0.05). At 45 days of age, exclusion resulted in a 15.6% reduction in the percentage infection rate by S. Enteritidis in spleens or livers and a 34.4% reduction in the percentage infection rate of the caeca (P < 0.05).

Dynamics of protein 27 of avian leukosis virus and transforming growth factor beta2 in lymphoid leukosis susceptible and resistant broiler chicken breeding stock

The dynamics of the serum concentration of protein 27 (P27) of avian leukosis virus and transforming growth factor beta2 (TGF-beta2) were compared during the period between 29 and 59 weeks of age in two flocks of broiler chicken breeding stock undergoing outbreaks of severe lymphoid leukosis (LL) associated with persistent high mortality (susceptible) and in another two flocks of breeding stock with the presence of avian leukosis virus in association with low mortality due to LL (resistant). The average mean concentration of serum P27 in the LL-susceptible flocks was significantly higher (p<0.05) than that in the LL-resistant flocks in six out of seven samplings performed at 5-week intervals, between 29 and 59 weeks of age. The peak in the average rise of serum P27 in the LL-resistant flocks (309 pg/ml) was associated with the highest level of TGF-beta2 (1282 pg/ml) among all flocks and at all sampling times. The significance of TGF-beta2 in inhibition of lymphoid tumour development is discussed.

Humoral and cell-mediated immunopotentiation in vaccinated chicken layers by thymic hormones and zinc

The humoral and cell-mediated immunities to a trivalent killed vaccine, administered subcutaneously to white leghorn-chicken layers at 29 and 31 weeks of age, and containing antigens of infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV), and Newcastle disease virus (NDV), were quantitated in five vaccinated and one unvaccinated-control group. Four out of the five vaccinated groups were immunopotentiated by various combinations of zinc and thymic hormones administered intraperitoneally in a volume of 0.1 ml per bird at an interval of three days for a period of three weeks, starting at 29 weeks of age. At each time interval, each bird of the first group received thymulin (10 ng) and ZnCl2 (1 microM), while each bird of the second group received thymopoietin (25 ng) and ZnCl2 (1 microM); in the third group, each bird received thymulin (10 ng), thymopoietin (25 ng), and ZnCl2 (1 microM), while each bird of the fourth group received only ZnCl2 (1 microM). Birds of the fifth group were only vaccinated and the control birds in the sixth group were left without vaccination or other immunopotentiation. Among all combinations, the thymulin-ZnCl2 resulted in birds with the highest humoral immunopotentiation to IBV, IBDV, and NDV antigens with respective percent increase in the mean titer at 33 weeks of age, compared with initial titer at 29 weeks of age, equivalent to 199%, 671.7%, and 86.4%. The highest cell-mediated delayed hypersensitivity reaction, measured at 48 h following an intradermal administration of the trivalent vaccine in the wattles at 33 weeks of age, was obtained in chickens immunopotentiated by the thymulin-thymopoietin-ZnCl2 combination.

Evaluation of an enrofloxacin-treatment program against Mycoplasma gallisepticum infection in broilers

Three chicken broiler breeder flocks, 7 months of age, were confirmed to have Mycoplasma gallisepticum (MG) infection, based on culture of tracheal swabs. A total of fifty-five 7-day-old embryos from the three MG-positive flocks had an average 27.4% prevalence of MG-infection in their vitelline membrane. Sixty randomly selected MG isolates (30 from individual tracheas of breeders and another 30 from individual vitelline membrane of embryos) were highly sensitive in vitro to enrofloxacin (100%). Three broiler flocks (averaging 15,000 birds per flock) from the same three MG-infected chicken boiler breeders were divided into halves. The first halves were subjected to an enrofloxacin-treatment program and the other halves were controls. Sera collected at different ages of the broiler flocks were tested by the enzyme-linked immunosorbent assay for antibodies to MG. The absence of MG titers at 45 days of age in birds subjected to the enrofloxacin-preventive program was compared to an average prevalence of 15.9% in the controls (p < 0.05). The lack of MG titers in 45-day-old birds subjected to the enrofloxacin-treatment program was associated with lower better feed-conversion ratios (p < 0.05).

National surveillance of poultry diseases in Lebanon

From 1992 to mid-1996, a national survey of poultry diseases in Lebanon was conducted. This surveillance included meat breeder, layer breeder, commercial layer and chicken broiler flocks. The history, signs, lesions and laboratory tests of poultry were used in the diagnosis of prevalent poultry diseases. Culture techniques were used to screen for bacterial diseases; serological techniques and, to a lesser extent, culture techniques were used to diagnose viral diseases; and both serological and culture techniques were used to diagnose Mycoplasma infections. The outbreaks of diseases detected in broiler breeder flocks and the number of such flocks experiencing these diseases were as follows: femoral head necrosis (6), egg-drop syndrome (3), reovirus-associated malabsorption syndrome (3), synovitis (Mycoplasma synoviae infection) (7), swollen head syndrome (SHS) (3), tenosynovitis (viral arthritis) (1), lymphoid leukosis (3), avian encephalomyelitis (1), fowl pox (1) and aortic rupture (1). The disease outbreaks detected in layer breeders were as follows: SHS (2), bumble foot (2), egg-drop syndrome (3) and avian infectious bronchitis (IB) (1). The disease outbreaks detected in commercial layer flocks were as follows: egg-drop syndrome (5), avian infectious laryngotracheitis (2), avian IB (nephrogenic strain) (1), malabsorption (1), avian tuberculosis (Mycobacterium avium) (1), Marek's disease (1), fowl pox (1), Salmonella enterica subsp. enterica Enteritidis infection (1), salpingitis (1) and Heterakis gallinae infestation (1). The disease outbreaks detected in broiler flocks were as follows: colibacillosis (40), infectious bursal disease (Gumboro disease) (15), malabsorption syndrome (8), avian infectious laryngotracheitis (8), paratyphoids (salmonellosis) (7), femoral head necrosis (8), SHS (6), avian mycoplasmosis (Mycoplasma gallisepticum infection) (6), synovitis (7), avian IB (6), botulism (1), avian encephalomyelitis (1) and gangrenous dermatitis (1). Diseases which occurred and which were reported for the first time in Lebanon were as follows: bumble foot, femoral head necrosis, avian IB (nephrogenic strain), malabsorption syndrome and SHS. This surveillance helped to establish baseline data concerning the predominant poultry diseases in Lebanon. Such information is a prerequisite for future regional and international collaboration to identify the source of the aetiological agents and to control their spread to neighbouring countries.

Bacterial identity and characteristics in healthy and unhealthy respiratory tracts of sheep and calves

The aim of this study was to compare different bacteriological aspects of the respiratory systems of healthy (H) versus unhealthy (UH) animals with respiratory signs. The prevalence of different bacterial species was determined in the upper and lower respiratory tract of H and UH Najdi sheep, Somali sheep and Holstein calves. The characteristics of Pasteurella spp. isolates, and the biotype of Pasteurella haemolytica were identified in H and UH animals, Eighteen out of 28 (64.3%) of the identified bacterial species in the upper respiratory tract were more prevalent in the nasal cavities of UH Najdi and Somali sheep and Holstein calves with respiratory signs than in apparently healthy animals; four of the most prevalent bacteria in the upper respiratory system of UH sheep were Moraxella spp., Pseudomonas pseudomallei, Erysipelothrix spp., Pasteurella multocida, while three of the most prevalent bacteria in UH calves were Pasteurella haemolytica, Actinomyces spp., and Pseudomonas aeruginosa. The prevalence of six different bacterial species was greater in the lungs of UH animals, namely Actinomyces pyogenes, Erysipelothrix spp., P. haemolytica, Pasteurella ureae, Staphylococcus aureus, and Staphylococcus epidermidis, which could be risk factors in the complexity of the prevalent respiratory diseases of the animals surveyed. Of the biochemical, cytological and colonial characteristics studied in the identified P. haemolytica and P. multocida, two characters were significantly different (p < 0.05) in organisms isolated from UH as compared to those from H animals. These were the higher loss of haemolytic power by the strains of P. haemolytica and the decreased fermentation of trehalose by all the strains of P. multocida recovered from healthy animals. The only biotype of P. haemolytica isolated from H animals was biotype A, while both biotypes A (88.0% of the isolates) and T (12.0% of the isolates) were recovered from UH animals.

Comparison of performance and mortality in the hybro normal and hybro giant meat poultry breeders and their offspring

The performance and mortality of similarly managed parent flocks of Hybro Normal and Hybro Giant meat poultry was compared. The overall daily egg production at 6-9 months of age was insignificantly greater in the Hybro Normal compared to the Hybro Giant parents (p > 0.05). The Hybro Normal parents had a significantly higher average daily egg production (56.08%) compared to that of the Hybro Giant parents (52.03%) during their sixth month of age, one month before the production peak (p < 0.05). The Hydro Giant parent-males had a significantly higher average daily mortality during the sixth and seventh months of age compared to the parent males of the Hybro Normal breed (p < 0.05); however, the females of the Hybro Normal parents had a significantly higher daily mortality during the sixth month of age compared to the Hybro Giant parent females (p < 0.05). The percentage hatchability was significantly lower in eggs collected from Hybro Giant birds compared to those collected from the Hybro Normal birds during the sixth and ninth months of age. The mean live weights at 45-days old of five flocks of Hybro Normal offspring was 1535 g compared to a mean live weight of 1870 g of five similarly managed flocks of the offspring of the Hybro Giant birds (p < 0.05). The feed conversion by the offspring of both breeds was not significantly different (p > 0.05). The mean percentage lameness in the five flocks of the offspring was 2.34% for Hybro Normal and 9.26% for Hybro Giant (p < 0.05). In summary, the overall performance of the Hybro Normal parent stock was superior to the Hybro Giant breeders regarding egg production and hatchability of their eggs; however, the weight gain of the Hybro Giant broiler flocks was superior to that of the Hybro Normal, but this was associated with a higher incidence of lameness.

Comparison of immunity and resistance to diseases in male and female poultry breeders in Lebanon

The immune responses following vaccination and resistance to diseases were compared in male and female meat poultry breeders of the same flock. Female poultry breeders maintained antibody titres to Newcastle disease virus and infectious bronchitis virus up to the fifty-fifth day following vaccination, whereas those of the males declined significantly over the same period of time (P < 0.05). In the same flock, outbreaks of Gumboro disease (60 to 62 days of age), coccidiosis (68 to 74 days of age) and aortic rupture (99 to 112 days of age) produced significantly higher losses in males. Following vaccination against fowl pox by the wing web method, 96.7% of females had a vaccine reaction (vaccine take) compared to none of the males. Immune injuries, following vaccination, were observed in 85% of the males compared to none of the females. The immune injuries included appearance of facial papules, vesicles, and reddish brown to black scabs.

Evaluation of bacterins containing three predominant phage types of Salmonella enteritidis for prevention of infection in egg-laying chickens

Six Salmonella enteritidis bacterin formulations differing in adjuvant content and whole-cell inactivation procedures were evaluated in egg-laying chickens. Chickens given S enteritidis bacterins containing modified Freund's incomplete adjuvant had greater humoral immune responses to S enteritidis than did birds given other bacterin formulations (P < 0.05). Better protection against infection by S enteritidis phage types 8, 13a, and 23 was obtained in birds vaccinated with bacterin 5. Bacterin 5 contained S enteritidis cells inactivated by 20% acetone and modified Freund's incomplete adjuvant.

Evaluation of cell culture propagated and in vivo propagated hemorrhagic enteritis vaccines in turkeys

The immune response of turkeys to a liquid, was compared with a previously frozen, cell culture propagated hemorrhagic enteritis (HE) vaccine. The liquid cell culture propagated HE vaccine was able to induce 100% seroconversion in turkeys 4 weeks after being vaccinated at 3.5 weeks of age; however, the previously frozen cell culture propagated HE vaccine induced 80% seroconversion 4 weeks post vaccination (P < 0.05). The average seroconversion in turkey flocks administered the liquid cell culture propagated HE was 97% in comparison with 98.5% in flocks given the splenic vaccine (P > 0.05). The complete absence of HE antigens in spleens of birds 5 days after being challenged with the virulent HE virus (40,000 TCID50 per bird) at an age of 9.5 weeks, was used as a model for successful protection against HE disease. The HE antigens were absent from spleens of all challenged birds that were previously vaccinated by the liquid cell culture propagated HE vaccine or splenic vaccine.

Serological response in broiler chicks to different commercial Newcastle disease and infectious bronchitis vaccines

Broiler chicks were administered vaccines against Newcastle disease and infectious bronchitis (both Arkansas and Massachusetts strains) at 2 weeks of age as either primary or secondary vaccinations. The vaccine was administered as a spray at 2 weeks of age to chicks that had received Newcastle disease vaccine alone, bronchitis vaccine alone, both vaccines in combination, or no vaccine at day 1 in the hatchery. The Newcastle disease hemagglutination-inhibition response was significantly lower in chicks receiving Newcastle disease vaccine as a secondary vaccine at 2 weeks than in those receiving the vaccine as a primary vaccination at that age. In contrast, the bronchitis hemagglutination-inhibition response was significantly higher in chicks receiving bronchitis vaccine as a secondary vaccination at 2 weeks than in those receiving the vaccine as a primary vaccination at that age.

An enzyme-linked immunosorbent assay for detection of Bordetella avium infection in turkey flocks: sensitivity, specificity, and reproducibility

An enzyme-linked immunosorbent assay (ELISA) for detection of Bordetella avium infection in turkey poults was developed. One-week-old poults challenged intratracheally with 10(12) colony-forming units of B. avium had detectable titers (greater than or equal to 11), with an average of 13.6% positive samples when the birds were 6 to 11 weeks old. The method was sensitive enough to detect maternal antibodies to B. avium in poults up to 3 weeks of age. The same poults challenged at 1 week of age had 100% tracheal infection up to 3 weeks of age, which dropped to 0% by 6 weeks. The method resulted in no false-positive samples (titer = 0) from birds not infected with B. avium and tested weekly between 4 and 11 weeks of age. Antibodies in turkey flocks infected with Newcastle disease virus, hemorrhagic enteritis virus, and Mycoplasma meleagridis, and birds infected with Escherichia coli had no apparent cross-reactivity to the B. avium antigens used in the ELISA. The percentages of B. avium-positive serum samples collected from different turkey flocks did not significantly differ (P greater than 0.05) when samples were tested by the developed ELISA at different times, an indication of the reproducibility of the method.

Characteristics of Actinomyces pyogenes involved in lameness of male turkeys in north-central United States

A new condition of clinical lameness in 20 male turkey flocks of North-Central United States, associated with isolation of gram-positive rod bacteria from lesions of osteomyelitis, is characterized. The characterization confirmed the randomly selected isolates as Actinomyces pyogenes based on macroscopic and microscopic observations and 17 biochemical tests. The disease was reproduced within 3 weeks in all male turkeys, following an intravenous challenge at 15 weeks of age. The agar gel precipitin test and immunoblotting confirmed the antigenic similarity of the isolates recovered from the osteomyelitis lesions of lame birds.

Preliminary data on efficacy of Mycoplasma gallisepticum vaccines containing different adjuvants in laying hens

Chickens were vaccinated subcutaneously twice, at 13 and 17 weeks of age. The vaccines used were the whole organisms of Mycoplasma gallisepticum (MG) adjuvanted with multilamellar positively charged (MPC) liposomes or oil-emulsion. Other chickens received the same bacterins but supplemented with Salmonella typhimurium cell wall protein mitogen (STP) (50 micrograms/dose). At 21 weeks of age, each bird was challenged in the right and left caudal thoracic air sacs. The challenge dose/chicken was 1.3 x 10(5) CFU of MG (R-strain). A significant immunoglobulin (Ig) response specific to MG was observed in sera of chickens collected 3 weeks after the first and second vaccination with MG adjuvanted with MPC liposomes or oil-emulsion. The same two treatments had highly significant MG-titers in eggs collected during the first and second month post challenge. Both groups had highly significant protection (P less than 0.05) against MG transmission in eggs layed during the first month post challenge. Vaccination with MG organisms adjuvanted to MPC liposomes or oil-emulsion resulted in higher egg production, during the first month following challenge, in comparison to the unvaccinated-challenged birds; the same two groups had higher egg production in the second month following challenge compared to unvaccinated-challenged birds, but not significantly different (P greater than 0.05). The addition of STP to bacterins containing MG organisms adjuvanted to MPC liposomes or oil-emulsion, resulted in a significant reduction (P less than 0.05) of the Ig-specific to MG in sera and in a significant drop in egg production (P less than 0.05) during the first month following challenge.

Identification of the antigenic components of paramyxovirus-3, paramyxovirus-6 and Newcastle disease virus in turkeys

The aim of this study was to use the enzyme-linked immunosorbent assay (ELISA) and the Western immunoblotting as possible tools to differentiate infections in turkeys by different paramyxoviruses. Pooled hyperimmune sera of turkeys infected with either paramyxovirus-3 (PMV-3), paramyxovirus-6 (PMV-6), or Newcastle disease virus (NDV) were assayed for antibodies specific to the three viruses by the ELISA and Western immunoblotting. ELISA results showed cross reactions of turkey antibodies between PMV-3 and PMV-6 antigens, while turkey antibodies to NDV did not cross-react with any of the other paramyxoviruses. The immunoblots of sera from birds infected with PMV-3 (Minnesota turkeys and Iowa chickens) reacted to low molecular weight polypeptides of PMV-3 of 29, 32, and 34 kDa, and to a high molecular weight band of 200 kDa. The same Minnesota turkey sera had a cross reaction to the 200 kDa polypeptide of PMV-6, while the Iowa chicken sera did not. Both sera had no apparent reaction to NDV proteins. Western immunoblotting showed that the turkey PMV-3 sera had a specific reaction to a 220 kDa polypeptide present in PMV-3, but not in PMV-6, while the turkey PMV-6 sera had a specific reaction to a 130 kDa polypeptide present in PMV-6, but not in PMV-3. Immunoblots of pooled sera from turkeys infected with PMV-6 (Minnesota source) reacted to the 200 kDa protein present in both PMV-3 and PMV-6; however, no reaction occurred between this sera and NDV proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of Mycoplasma gallisepticum subunit and whole organism vaccines containing different adjuvants by western immunoblotting

Chickens were vaccinated with subunit (adhesin protein) or whole organisms of Mycoplasma gallisepticum (MG) adjuvanted with multilamellar positively charged liposomes or oil-emulsion. Sera were collected before and following the first (13 weeks of age) and second (17 weeks of age) vaccination. The chicken sera were used in western immunoblotting against whole MG polypeptides. Vaccination with the subunit (MG-adhesin) bacterin containing positively charged liposomes resulted in antibody response specific to adhesin band (75 kD) at 3 weeks post the first and second vaccination; however, crossreactions of the same antibodies occurred to MG proteins of 85 kD (3 weeks after the first vaccination) and 56 kD (3 weeks after the second vaccination). Vaccination with whole MG proteins containing positively charged liposomes resulted in significant immunopotentiation of antibodies against low molecular weight polypeptides of MG (less than 48.0 kD). The addition of Salmonella typhimurium cell wall proteins mitogens (STP) to the different bacterins suppressed the antibody responses to some MG polypeptides.

Identification of the antigenic components of the virulent Mycoplasma gallisepticum (R) in chickens: their role in differentiation from the vaccine strain (F)

The antibody response to different proteins of Mycoplasma gallisepticum (MG) was studied in chickens experimentally infected with virulent MG R strain. The chickens were challenged at 8 weeks of age by the intranasal route. Each cockerel received 1.3 X 10(6) colony-forming units (CFU). MG strains (R and F) were banded by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The banding pattern was distinctively different between the two strains in the range of 92.5 to 200 kilodaltons (kD). Chicken sera collected at different times following challenge were analyzed by Western blot to determine the patterns of antibodies raised to specific MG proteins (R versus F strains). Early in infection (2 weeks postchallenge), antibodies to 60-kD and 75-kD polypeptides of MG R strain were produced. Subsequently (greater than or equal to 4 weeks postchallenge), antibodies recognized a larger number of MG antigens in both strains. The immunoblot patterns remained the same in the period 8-11 weeks postinfection in each of the two strains; however, the patterns were different when the two strains were compared. The early response recognized the 75-kD protein in the R strain while it recognized the 80-kD protein in the F strain. The late response recognized the 130-kD protein and the protein slightly heavier than 200 kD in the R strain. These two bands did not appear in the immunoblot performed against the F strain of MG. Electroeluted protein of MG R strain, namely adhesin (75 kD), showed a hemagglutination activity (HA) on chicken red blood cells. With the appearance of antibodies specific to the 60-kD and 75-kD polypeptides, there was a significant rise in hemagglutination-inhibition geometric mean titer of chicken sera.

New biotin-conjugated antisera for quantitation of Mycoplasma gallisepticum-specific immunoglobulin A in chicken

The biotinylation of goat anti-alpha-chains of chicken immunoglobulin A (IgA), suitable for use in an avidin-biotin enzyme-linked immunosorbent assay, is described. The optimum conditions for the use of the developed conjugate in determining local and systemic IgA specific to Mycoplasma gallisepticum in chickens were established.

A rapid computerized method for quantitation of cellular mediated immunity in biological systems

The aim of this study was to compare the quantitation of cellular mediated immunity (CMI) assessed by leukocyte migration (LM) using a Hewlett Packard Model 9825A Desk-top computer interfaced to a Talos Cyber Graphics Digitizer vs. the standard quantitation done by tracing the projected profile of the migrated leukocytes on papers, cutting and weighing. The computerized quantitation resulted in a percentage migration mean of 75.91 as compared to standard quantitation by weighing (76.37) (P greater than 0.05). The unweighted least squares linear regression resulted in R2 0.9987, an indication of a high correlation between the data obtained by both methods. The advantages of computerized quantitation of cellular mediated immunity are discussed.

Protection and immunity in commercial chicken layers administered Mycoplasma gallisepticum liposomal bacterins

Six liposomal Mycoplasma gallisepticum (MG) bacterins, differing in charge and size, and two oil-emulsion vaccines (sonicated and non-sonicated) were given to white leghorns in two doses, at 13 weeks and again 1 month later. At 21 weeks of age, all chickens were challenged with a viable 20-hour culture of MG cells (17,800 colony-forming units) intratracheally and with nonviable MG organisms (0.09 mg protein) injected subcutaneously in the wattle center. The three chicken groups that had the lowest tracheal MG-infection rates postchallenge were those given adjuvants of small multilamellar positively charged liposomes (16.67%), large multilamellar negatively charged liposomes (16.67%), and non-sonicated oil-emulsion bacterin (37.5%). These three groups also had significant levels of antibody in sera 4 weeks after the second dose of vaccine. The group given the small multilamellar positively charged liposome also showed significant delayed-type hypersensitivity (wattle swelling) (P less than or equal to 0.05). The group given the large multilamellar negatively charged liposomes had the highest local antibody response (P less than or equal to 0.01) and was the only group that had no microscopic lesions in the trachea.

O-serotypes of Pseudomonas aeruginosa from animal and inanimate sources in Saudi Arabia

A total of 1012 samples were examined for Pseudomonas aeruginosa and 257 (25.4%) were positive. The incidence of Ps. aeruginosa in samples collected from animal sources (N = 730) was significantly higher (28.7%) than that in 282 samples of inanimate sources (16.7%). The percentage of samples infected with these organisms was lowest in poultry feed (2.8%) and highest in sewage effluent (57.1%). Nine serotypes were defined from all sources. P5 was the common predominant individual O type in infected chicken navels and in the nasal cavities of Najdi sheep (a Saudi Arabian sheep breed), while P3 and P6 were predominate in the nasal cavities of Somali sheep (a breed imported from Somalia). No Ps. aeruginosa serotype was predominant in sheep faeces. In inanimate sources, P4 was predominant in water and sewage effluent. The isolate from the animal feed was untypeable. In using the slide agglutination technique for serotyping, most of the unusual agglutination reaction types of Ps. aeruginosa (70%) were of strains isolated from Somali sheep.

Mastitis in Camelus dromedarius in Saudi Arabia

The correlation between camels' milk samples collected from abnormal inflamed udders and samples positive in the California Mastitis Test (CMT) was +0.803 (P less than 0.01). The bacterial count ranges of milk samples differed significantly (P less than 0.05) for those with a negative CMT and those with a positive CMT. Infection with many but not all bacterial species was associated with positive CMT results. The highest percentage of camel milk samples was included in the bacterial count range of 3.0 x 10(2) to 3.0 x 10(3) cfu/ml rather than in the greater than 3.0 x 10(3) cfu/ml range for most of the bacterial species. The most predominant bacterial isolates were Micrococcus spp., Staphylococcus aureus, Streptococcus spp. and Corynebacterium spp. followed by eight other flora. Chloramphenicol was the most effective antimicrobial agent of six tested against 118 bacterial isolates. Preliminary observations are made on chemotherapy of mastitis cases in camels.

Use of epidemiologic markers to identify the source of Escherichia coli infections in poultry

During an epidemiologic study of poultry colisepticemia on 2 Saudi Arabian poultry broiler farms, Escherichia coli was isolated from 101 (40.4%) of the 250 specimens examined. The antigenic structure and the drug resistance pattern of 65.4% of the E coli isolates from different sources were used as epidemiologic markers to trace the source of the infection. The predominant E coli serotypes involved in infections of 2 poultry broiler progeny farms were 033:H4 (51.8%) and 078:H- (19.6%) that had the following respective drug resistance patterns: furazolidone-streptomycin-sulfathiazole and streptomycin-sulfathiazole-tetracycline. Escherichia coli strains with typical epidemiologic markers were isolated from various sources on a broiler breeding farm, but not from well waters of the infected progeny farm. Three other E coli serotypes (045:H10[14.3%], 0119:H27[1.8%], and 0145:H25[1.8%]) were involved in poultry infection, but to a lesser extent. These 3 serotypes were multiply resistant against 5 to 6 of the antimicrobials evaluated.

Production of H2S by Escherichia coli isolated from poultry: an unusual character useful for epidemiology of colisepticemia

Eleven isolates of H2S-producing Escherichia coli were recovered from necropsy materials of chickens with symptoms and lesions of colisepticemia on Saudi Arabian broiler farms. Results of 19 out of 20 biochemical reactions studied were typical for E. coli. Hydrogen sulfide production by the E. coli isolates was used as an epidemiological marker to pinpoint a breeding farm as the probable source of these strains, which were then transferred to progeny farms, where colisepticemia occurred. This finding was confirmed by the presence of the same antigenic structure (O78:H-) and by the same drug-resistance pattern (a multiple resistance to streptomycin, sulfathiazole, and tetracycline) in the isolates.

Reduction of bacterial infections in newly hatched chicks by the use of antimicrobial dips: preliminary approaches

Bacteriological examination of hatchery waste eggs, identification of the isolated bacteria, and susceptibility testing against seven antimicrobial agents were used in an attempt to establish a rational basis for reducing bacterial infections in newly hatched chicks. Chloramphenicol at 1000 ppm was selected as the antibiotic for preliminary dipping trials and 0.45% iodophore (Wescodyne) was added for later trials. The control treatment consisted of formaldehyde fumigation. The following conclusions can be drawn: Hatchery waste eggs are highly contaminated (69.1%) and enterobacteriaceae predominate (26.6%). Chloramphenicol is the most effective antimicrobial tested. Dip treatments with either chloramphenicol alone or chloramphenicol plus Wescodyne result in a reduced percentage of abnormal navels (8.4% and 10.4%), as compared with 21.9% for the control treatment. Hatchability of either group of dipped eggs is reduced in comparison with fumigated eggs. Dip treatment with chloramphenicol plus Wescodyne significantly reduces the anal carrier rates for Escherichia coli, Pseudomonas aeruginosa, Salmonella spp., and Staphylococcus aureus. This treatment reduces the incidence of bacterial infection in abnormal navels to zero.

Effect of management changes on hatchability and bacterial infections on a Saudi Arabian poultry breeding farm

A new management programme for improvement of hatchability and reduction of transmission of bacterial potential pathogens from breeders to hatchery products was applied on a Saudi Arabian poultry farm. The technical changes included better nest engineering, improved cleaning of hatching eggs and better criteria for selecting eggs for incubation. The new nests led to a change in laying behaviour with 86.6% of eggs layed in nests which was significantly higher than was achieved previously. Bacterial penetration in dirty floor eggs was significantly higher than in clean nest eggs. The average hatchability was significantly higher for the flock under the new management than for the same age flock under the old management. The new management reduced transmission of paratyphoid organisms and Escherichia coli from infected breeders to their hatchery products. The old and new managements differed in the percentage of products infected with Salmonella.

A non-motile Salmonella mutant (6, 7:-:-) and two serological variants encountered in Saudi Arabia

A non-motile mutant of Salmonella group C1 and two serological variants were isolated during the performance of a national Salmonella surveillance program in Saudi Arabia. Most of the biochemical reactions of the strains conformed to those of the genus Salmonella except for some atypical reactions. The three strains exhibited different susceptibility patterns to 21 antimicrobial agents. The serological analysis revealed the following antigenic structures: 1, 4, 12, 27:b: - Salmonella sofia var. monophasic; 1, 42:z4, z23: - Salmonella gera var. monophasic and a Salmonella strain reported as a non-motile strain of group C1 by the World Health Organization International Collaborating Center for Reference and Research on Salmonella.

Distribution of paratyphoids on Saudi Arabian poultry farms and pathogenicity studies of predominant serotypes

A total of 412 feed samples and 632 litter samples from 15 poultry farms (2 breeding farms and 13 rearing farms) were examined for salmonella. Twelve of these farms had salmonella in litter, five farms had salmonella in the feed and four had salmonella in both feed and litter. Seventeen feed samples (4.13%) and 121 litter samples (19.15%) were contaminated with salmonella. Sixteen salmonella serotypes were encountered, of which six were found in both feed and litter. Salmonella concord and S. livingstone were present in the litter of one breeding farm and its progeny farms. The five most frequently isolated salmonella serotypes in feed and litter were S. concord (17.39%), S. coeln (15.94%), S. livingstone (15.22%), S. manhattan (11.59%), and S. paratyphi B var. java (8.69%). The pathogenicities of those serotypes were determined by calculating their median lethal doses (LD50) 24 and 48 hr postinjection of 1,050 one-day-old broiler chicks via the navel into the yolk sac. The composite 48-hr LD50s (viable cells) were: S. concord, less than 8.8 X 10(3); S. livingstone, 1.1 X 10(5); S. manhattan, 3.5 X 10(5); S. coeln, 1.25 X 10(7); and S. paratyphi B var. java, 1.73 X 10(7).

Occurrence of salmonellae in animal feed ingredients in Saudi Arabia

Of 346 samples of animal feed ingredients (144 complete feed, 88 feed concentrate, 42 calcium carbonate, 30 meat meal, 29 fish meal, and 13 mixed meat and bone meal), 42 (12.13%) were contaminated with salmonellae. The rate of Salmonella contamination varied according to the nature of the feed sample. Seven (53.84%) of the mixed meat and bone meal, 14 (48.27%) of the fish meal, 12 (13.63%) of the feed concentrate, 7 (4.86%) of the complete feed, and 2 (4.76%) of the calcium carbonate samples contained salmonellae. The 49 Salmonella isolates represented 18 serotypes; the 5 most frequent serotypes in decreasing order were S lille, S new-haw, S livingstone, S kentucky, and S typhimurium. The 4 most common somatic serogroups encountered were C1, E2, B, and C3.

Isolation of salmonella and some other potential pathogens from two chicken breeding farms in Saudi Arabia

Different salmonella serotypes were recovered from various sources in meat (A) and layer (B) poultry-breeder farms of Saudi Arabia. On farm A, salmonella were recovered from intestines of poultry breeders (7.41%), inshelled chicken embryos (2.87%), day-old chicks (19.23%), and mice (21.43%). Salmonellae in shell contents and on shell surfaces of hatching eggs contaminated the same percentage of eggs (1.24%), and litter and feed contaminations were 4.0% and 1.67%, respectively. On farm B, salmonella were recovered from intestines of poultry breeders (27.59%), mice intestines (15.0%), shells of hatching eggs (2.48%), hatching egg contents (0.35%), litter (33.33%), and feed (5.0%). No salmonella were recovered from intestines of inshelled chick embryos or day-old chicks on farm B. The total number of salmonella serotypes isolated from both farms was 14, and the serotypes common to both farms were Salmonella concord and S. livingstone. Salmonella contamination of shells of hatching eggs, pooled from both farms, was higher for dirty floor eggs than for clean eggs collected from floors and nests. The percentages of hatching eggs penetrated by bacteria other than salmonella on farms A and B, respectively, were: dirty floor eggs (25.53%, 22.83%), clean floor eggs (2.67%, 2.06%) and clean nest eggs (0.00%, 1.08%). The bacterial flora isolated from egg contents of unincubated hatching eggs (in decreasing order of frequency) were Staphylococcus, coliforms, Streptococcus, Bacillus, Salmonella, and Proteus.

Salmonella species and serotypes isolated from farm animals, animal feed, sewage, and sludge in Saudi Arabia

A total of 264 salmonellae representing 65 different species and serotypes were isolated for the first time in Saudi Arabia, from various animal species, animal feed, sewage, and sludge. The six most frequently isolated Salmonella species or serotypes were: livingstone, concord, "S. schottmuelleri" (invalid), lille, S. typhimurium, and cerro.

In vitro susceptibility of salmonellae to eight antimicrobial agents

The Bauer-Kirby disk diffusion method was used to determine the susceptibility of 333 strains of Salmonella isolated in Saudi Arabia to eight antimicrobial agents. The following susceptibilities were observed: Cephalothin 99.40%, furadoine 99.10%, chloramphenicol 98.80%, ampicillin 98.20%, polymyxin 96.70%, kanamycin 95.80%, streptomycin 90.99%. Only 50.45% of the strains were susceptible to tetracycline, whereas 44.14% and 5.41% were respectively intermediate and resistant to this drug. The antibiograms displayed many resistant patterns. Some of the salmonellae were singly resistant while others were resistant to 2 or more drugs in various combinations. In view of the potential for salmonellae to have inherent or acquired resistance to certain commonly used antimicrobial agents, susceptibility of all isolates of salmonellae, particularly of all clinically significant strains should be determined periodically.