Evaluation of a sprinkler cooling system on inhalable dust and ammonia concentrations in broiler chicken production.

Workers are exposed to dust in broiler chicken production during daily work activities. Poultry dust may contain inflammatory agents (e.g., endotoxin) and inhalation exposure has been associated with pulmonary symptoms. Current practice to reduce worker exposure to poultry dust is the use of respiratory protection (e.g., elastomeric face-piece respirator with a P100 and ammonia chemical cartridge). Limited research has been conducted to evaluate engineering controls to reduce dust and ammonia concentrations in broiler chicken production; therefore, the purpose of this research was to evaluate the effectiveness of a water sprinkling system to reduce inhalable dust and ammonia concentrations in a broiler chicken house. Inhalable dust and ammonia concentrations were measured daily for the production cycle of a flock of broiler chickens (63 days). Inhalable dust was measured gravimetrically using an inhalable sampler and ammonia was measured by a direct reading sensor. Sampling was performed on a stationary mannequin inside two broiler chicken houses. One house used a sprinkler cooling system to deliver a water mist throughout the house and the second house was an untreated control. The sprinkler system activated after day 5 of chicken placement, releasing water periodically from 6 am to 10 pm. The amount of sprinkling increased at day 10 and day 15 as recommended by the manufacturer. Geometric mean (GM) inhalable dust concentrations measured in the treatment house (5.5 mg/m3) were not different (p = 0.33) than those found in the control house (6.0 mg/m3). The GM ammonia concentrations were also not different (p = 0.34) across the treatment and control house [10.6 ppm (GSD: 1.80); GM 9.51 ppm (GSD: 1.77)], respectively. The use of cost effective engineering, administrative and personal exposure controls are needed in the poultry industry to effectively reduce worker's exposure to hazardous concentrations of dust and ammonia.

Arginine and vitamin E improve the immune response after a Salmonella challenge in broiler chicks.

Two experiments were conducted to evaluate the effects of Arg, vitamin E (VE), and mannanoligosaccharide (MOS) on the immune response and clearance of Salmonella in broiler chickens. In each experiment, 1-d-old chicks (n = 160) were randomly distributed into 4 groups: antibiotic-free diet (negative control, CTL-), antibiotic-supplemented diet (positive control, CTL+), antibiotic free-diet plus Arg and VE (AVE), or antibiotic-free diet plus Arg, VE, and MOS (AVM). Birds were orally challenged with 10(6) cfu of a novobiocyn and nalidixic acid-resistant Salmonella enterica serovar Typhimurium strain at d 7 (experiment 1) or at d 3 (experiment 2). Heterophil- (HOB) and monocyte- (MOB) oxidative burst and lymphocyte proliferation (LPR), antibody titers, and Salmonella content in the ceca were measured at several intervals postinfection (PI). In experiment 1, both AVM and AVE decreased HOB compared with the controls 5 and 9 d PI, but increased LPR 9 d PI. In the same experiment, birds fed the AVE diet had higher MOB than birds fed CTL+ or the AVM diet at 7 d PI, whereas 9 d PI birds fed the AVM diet had the highest MOB. In experiment 2, birds fed the AVE diet had higher MOB, HOB, and LPR than birds in the other treatments 7 and 14 d PI, except at 7 d PI, when MOB was not different among treatments. Birds fed the AVM diet had the highest IgA antibody titer, and a higher IgM antibody titer than the CTL+ birds. In experiment 1, Salmonella Typhimurium content in the ceca was lower in birds fed the AVM diet compared with birds fed the CTL- diet 3 d PI, but later on (10 and 17 d PI), and in experiment 2 (7, 14, and 21 d PI), Salmonella Typhimurium concentrations were not different among treatments. Thus, Arg and VE improved immune response after a Salmonella Typhimurium challenge in young chicks, and although they did not reduce Salmonella Typhimurium concentrations in the ceca, they may improve bacterial resistance against other pathogens in commercial growing conditions.

Evaluation of probiotic administration on the immune response of coccidiosis-vaccinated broilers.

Probiotics are nonpathogenic bacteria that can promote bird health by reducing pathogen colonization. Researchers have previously demonstrated that the avian immune response can be modulated with probiotics, which may provide a mechanism for the reported reductions in pathogens. We examined phagocyte oxidative burst and cell proliferation of vaccinated broilers administered probiotics. We hypothesized that the combination of probiotic bacteria and a vaccine would affect immune function. Two studies were conducted to evaluate this interaction in broilers. Treatments consisted of a negative control, probiotic, vaccine, or a probiotic + vaccine. Peripheral blood was collected on d 7, 14, and 21 of age. Heterophils and monocytes were evaluated for oxidative burst and lymphocytes were assayed for proliferation. In study 1, heterophil oxidative burst was higher (P ≤ 0.05) in each treatment that received probiotic on d 14 when compared with the negative control. On d 21, an enhanced (P ≤ 0.05) heterophil oxidative burst was observed in the probiotic treatment when compared with the other treatments. On d 14, monocyte oxidative burst was greater (P ≤ 0.05) in the probiotic + vaccine treatment when compared with all other treatments. An increase (P ≤ 0.05) in lymphocyte proliferation was observed among all treatments on d 7 when compared with the negative control. Both vaccine treatments had significant lymphocyte proliferation on d 14 when compared with the negative control. In study 2, the probiotic treatment was associated with greater levels in heterophil oxidative burst on d 7 when compared with all other treatments. On d 21, an increase (P ≤ 0.05) in heterophil oxidative burst was seen in the vaccine treatment when compared with the negative control. On d 7, increased (P ≤ 0.05) monocyte oxidative burst was observed in the vaccine treatment when compared with the negative control. No significant differences were observed in lymphocyte proliferation in any of the treatment groups. These data suggest that probiotics can modulate the immune response and may play a role in vaccination.

Immune response of broiler chickens fed different levels of arginine and vitamin E to a coccidiosis vaccine and Eimeria challenge.

One-day-old broiler chicks (n = 300) were orally vaccinated (Coccivac-B) and divided into 6 groups to evaluate Arg at 3 levels of supplementation, 0, 0.3, or 0.6% [normal level (NARG), medium level (MARG), or high level (HARG), respectively], and 2 levels of vitamin E (VE), 40 or 80 IU/kg of feed (VE40 or VE80, respectively), in a factorial experiment. Birds were reared in floor pens with fresh pine shavings and provided a corn-soybean-based diet and water ad libitum. At d 14, all chickens were orally challenged with a mixture of Eimeria field isolates (Eimeria acervulina, Eimeria maxima, and Eimeria tenella). In vitro heterophil and monocyte oxidative burst (HOB and MOB, respectively) was measured at d 21 from cells isolated from peripheral blood. Antibody levels (IgG, IgM, and IgA isotypes, ELISA) and NO were measured at d 14 and 28. The HOB was lower in birds fed the VE40 diets but was increased with the MARG and HARG treatments, whereas birds fed the VE80 diet had a higher HOB irrespective of Arg level. Birds fed the VE80 diet had high levels of MOB, which was not further improved by Arg, whereas birds fed the VE40-MARG diet had the highest MOB response. Plasma NO was not affected by diet at d 14, but at d 28, plasma NO was higher in birds fed the VE80-MARG or the VE40-NARG diet and lower in birds fed the VE80-NARG or the VE40-MARG diet. Birds fed the VE40-HARG or VE80-MARG diet had the highest IgG levels at d 14, but at d 28, birds fed the VE80-MARG diet had the highest IgG levels. The IgM concentration was lower in birds fed NARG levels irrespective of VE levels at d 14, but at d 28, IgM levels were higher in birds fed the VE40-HARG or the VE80-MARG feed. The IgA concentration was not consistently affected at d 14 or 28. These results suggest that Arg and VE fed at levels higher than those recommended by the NRC may play complementary roles on the innate and humoral immune response against an Eimeria challenge, potentially improving vaccine efficacy and response to field infections.

Bacterial clearance, heterophil function, and hematological parameters of transport-stressed turkey poults supplemented with dietary yeast extract.

Yeast extracts (YE) contain biological response modifiers that may be useful as alternatives to antibiotics for controlling pathogens in poultry production and mitigating the deleterious effects of production stressors. The objective of the present study was to determine the ability of a commercial dietary YE (Alphamune) to modulate the immune response in male turkey poults challenged with Escherichia coli and subjected to transport stress. Alphamune was added to turkey poult diets at 0, 500, or 1,000 g/ton. Poults were challenged by air sac injection with 60 cfu of E. coli at 1 wk of age. At 3 wk of age, these challenged birds were subjected to transport stress and birds were bled and necropsied the following morning. Blood cell numbers and percentages, hematological parameters, and clinical chemistry values were determined. Oxidative burst activity of isolated heterophils was measured using stimulation with phorbol myristate acetate and a 2',7'-dichlorofluorescein diacetate assay. Data were analyzed using GLM and least squares means procedures of the SAS program. The numbers and percentages of heterophils in peripheral blood were increased and their oxidative burst activity was stimulated by YE. The stress challenge dramatically increased oxidative burst and this increase was significantly modulated by YE treatment. Serum levels of calcium, phosphorus, and triglycerides were decreased and uric acid levels, erythrocyte numbers, hemoglobin, and hematocrit were increased by YE supplementation. Bacteria were isolated from the air sac and liver of a lower percentage of birds provided with YE. These results suggest that dietary YE has potential as a nonantibiotic alternative for decreasing bacterial pathogens in turkey production.

Pasteurization of chicken litter with steam and quicklime to reduce Salmonella Typhimurium.

The nursery industry pasteurizes soil with steam and quicklime to reduce plant pathogens. The mechanism of action for quicklime is the resulting exothermic reaction that occurs when the chemical interacts with water and its ability to increase pH levels. These treatments may also reduce pathogens in a commercial poultry house. In this study, a steam sterilization cart simulated conditions used by the nursery industry to treat litter inoculated with Salmonella enterica serovar Typhimurium. A homogenized sample of litter was exposed to steam for 0, 5, 30, or 120 min. Quicklime was used at concentrations of 0 (control), 2.5, 5.0, or 10.0%. All steam treatments, with or without quicklime, significantly reduced Salmonella Typhimurium colonization by at least 3 orders of magnitude. Significant reductions were also observed in the treatments with quicklime alone. Both the steam and the quicklime treatments often reduced colonization to undetectable levels, even when samples were enriched. Therefore, we demonstrated 2 novel techniques for reducing Salmonella Typhimurium in poultry litter. Soil pasteurization potentially offers an environmentally sound means of reducing the pathogens present in used poultry litter.

Effect of bismuth citrate, lactose, and organic acid on necrotic enteritis in broilers.

Clostridium perfringens-associated necrotic enteritis causes significant economic losses. The objective of this study was to evaluate the effect of bismuth citrate, lactose, and organic acid on the development of necrotic enteritis in broilers. The first study was a dose response that evaluated bismuth citrate at 50, 100, or 200 ppm on bacterial intestinal colonization and lesion development associated with our C. perfringens challenge model. The second study evaluated bismuth citrate, lactose, and citric acid on intestinal pH and lesion development. For the third study, we determined if lactose would enhance the efficacy of bismuth citrate against intestinal colonization and lesion development associated with C. perfringens. In study 1, intestinal lesion scores at the 50, 100, and 200 ppm bismuth citrate treatment level were reduced (P < or = 0.05) when compared with the birds fed 0 ppm bismuth citrate. Intestinal C. perfringens colonization of the 100 and 200 ppm bismuth citrate treatment group was significantly reduced when compared with birds fed 0 ppm bismuth citrate. In study 2, we found no significant differences in lesion development, after C. perfringens challenge, between birds fed 100 ppm bismuth citrate or fed a combination of 100 ppm bismuth citrate with dietary lactose or citric acid relative to the controls. The intestinal pH of birds fed 100 ppm bismuth citrate or fed a combination of 100 ppm bismuth citrate with dietary lactose or citric acid was not significantly reduced when compared with the controls. However, a significant reduction in pH was observed in birds fed a combination of 100 ppm bismuth citrate and lactose relative to the negative controls. In study 3, a decrease (P < or = 0.05) in intestinal lesion scores occurred in birds fed lactose with 100 ppm bismuth citrate, compared with the positive controls. There were no significant differences in intestinal bacterial colonization. These preliminary data suggest that bismuth citrate may reduce intestinal lesion development and C. perfringens colonization in broilers infected with necrotic enteritis.

Evaluation of disinfectants commonly used by the commercial poultry industry under simulated field conditions.

The correct usage of disinfectants is an important component of a successful biosecurity program. The objective of this study was to determine the effect of time, temperature, and organic matter (OM) on disinfectant efficacy. Staphylococcus aureus and Salmonella Typhimurium were used to represent gram-negative and gram-positive bacteria commonly found in commercial poultry housing. The first study evaluated the effect of temperature (4, 20, 32, or 43 degrees C) and time (1, 2, 3, 4, 6, 8, 12, 16, 20, 24, and 30 wk) on the efficacy of disinfectants diluted to working concentrations. The second study determined the effect of OM on the efficacy of working concentrations of freshly prepared disinfectants against the bacteria. For the third study, we compared the bactericidal properties of freshly prepared disinfectants and 30-wk-old disinfectants in the presence of OM. Quaternary ammonium-, chlorhexidine-, phenolic-, and binary ammonium-based solutions represented disinfectants commonly used within the poultry industry. In the first study, all of the disinfectants were effective against S. aureus and Salmonella Typhimurium regardless of treatment. However, the phenolic compound had reduced (P

Dietary lactose and its effect on the disease condition of necrotic enteritis.

Clostridium perfringens is the etiologic agent of necrotic enteritis (NE) and is ubiquitous in nature. The incidence of NE has increased in countries and commercial companies that have stopped using antibiotic growth promoters. The mechanisms of colonization of C. perfringens and the factors involved in onset of NE are not fully understood. Previously, our laboratory has demonstrated that lactose could potentially reduce Salmonella and C. perfringens in ceca of poultry. In the present investigation, we hypothesized that dietary lactose would reduce the clinical signs of NE and could be used as an alternative to antibiotics. In experiment 1, day-of-hatch broilers were fed either a nonlactose control diet, a diet with 2.5% lactose, or a diet with 4.5% lactose throughout the experiment. Birds were administered C. perfringens (10(7) cfu/mL) daily via oral gavage for 3 consecutive days starting on d 17. When evaluating the intestinal lesions associated with NE, birds fed 2.5% lactose had significantly lower (P < 0.05) lesion scores (0.70 +/- 0.52) compared with the control (1.55 +/- 0.52) or the 4.5% lactose (1.60 +/- 0.52). The data from the microbial analysis showed that the addition of lactose did not affect any bacterial populations when compared with the control birds that did not receive dietary lactose over the 21-d evaluation. The overall lesion scores in experiment 2 were significantly (P < 0.05) reduced in birds fed 2.5% lactose compared with the birds fed the control diet with mean lesion scores of 1.10 +/- 0.73 and 1.80 +/- 0.73, respectively. These experiments suggest that lactose could be used as a potential alternative to growth-promoting antibiotics to help control this costly disease.

Gastrointestinal maturation is accelerated in turkey poults supplemented with a mannan-oligosaccharide yeast extract (Alphamune).

Alphamune, a yeast extract antibiotic alternative, has been shown to stimulate the immune system, increase BW in pigs, and reduce Salmonella colonization in chickens. The influence of Alphamune on gastrointestinal tract development has not been reported. Two trials were conducted to evaluate the effects of Alphamune on gut maturation of 7- and 21-d-old turkey poults. Poults were fed a standard control unmedicated turkey starter diet or the same diet supplemented with either 1 or 2 lb/ton of Alphamune (n = 18/group). Poults were weighed on d 7 and 21, euthanized, and a 2-cm section was collected from the midpoint of the duodenum, jejunum, and ileum of each bird (9 poults/d per treatment) and fixed in a 10% formalin solution for 72 h and then stained. Twenty measurements of villus height, villus surface area, lamina propria thickness, crypt depth, and density of neutral, sialomucin, and sulfomucin goblet cells were taken per section per poult. On d 7, BW were higher for the poults given the Alphamune treatments compared with control poults; however, no differences were observed on d 21. Alphamune supplementation influenced intestinal morphology differently based on gut location. Ileum villus height, surface area, lamina propria thickness, crypt depth, and neutral, sialomucin, and sulfomucin goblet cell density were enhanced with Alphamune treatments on d 7 and 21 (P < 0.05) and in a dose-dependent manner for many of the parameters evaluated. Jejunum results were mixed. Surface area, crypt depth, and sialomucin and sulfomucin goblet cells were consistently higher for the 2 lb/ton of Alphamune groups compared with the control group on d 7 and 21. Duodenum villus height, surface area, and goblet cell density were higher for the 2 lb/ton of Alphamune groups on d 7; however, intestinal morphology of the duodenum was not different between the control and treated birds on d 21. These results suggest that feed supplemented with Alphamune can accelerate gastrointestinal maturation in turkey poults and is more pronounced in the ileum than in other portions of the small intestine.

Influence of hen age on the response of turkey poults to cold stress, Escherichia coli challenge, and treatment with a yeast extract antibiotic alternative.

Two battery experiments were conducted to evaluate a commercial yeast extract feed supplement, Alphamune, in a cold stress-Escherichia coli challenge of 1-wk-old turkeys. Experiment 1 used 1-d-old male poults that were the progeny of 33-wk-old hens in their second week of lay. Experiment 2 used male poults of the same genetic line from 40-wk-old hens in their eighth week of lay. Poults were fed a standard unmedicated turkey starter diet or the same diet with either a low level (504 g/t) or a high level (1,008 g/t) of yeast extract. Challenged birds were exposed to intermittent cold stress during wk 1 to 3 and to a respiratory E. coli challenge at 1 wk of age. In both experiments, BW at wk 1 was increased by feeding yeast extract. In experiment 1, challenged, control-fed birds had decreased BW at wk 3 and feed conversion was protected by both levels of yeast extract supplementation. In experiment 2, challenge had no effect on control-fed birds; however, yeast extract decreased the BW of challenged birds. In experiment 1, total leukocyte numbers were decreased by challenge of control-fed birds only, and there was no effect of challenge on the heterophil/lymphocyte ratio. In experiment 2, total leukocyte numbers were decreased and the heterophil/lymphocyte ratio was increased in challenged, control-fed birds. Percentage mortality was not affected by challenge in experiment 1; however, in experiment 2, mortality was increased by challenge of control-fed birds and those fed the lower level of yeast extract. These results suggest that hen age should be considered when designing studies to evaluate antibiotic alternatives and in making decisions for incorporating such alternatives into production.

Upregulation of oxidative burst and degranulation in chicken heterophils stimulated with probiotic bacteria.

The immune system of neonatal chicks is functionally immature during the first week of life. Researchers have previously demonstrated that the avian humoral response can be increased with probiotics. Although the humoral response provides the chick with an effective mechanism to combat pathogens, sufficient antibody titers are not attained until 7 to 10 d postinfection. However, the innate immune system (i.e., heterophils) can respond much more quickly to pathogens. The objective of this study was to determine whether probiotic bacteria can also upregulate heterophil function. Heterophils were isolated from the peripheral blood of neonatal chickens by using a discontinuous density gradient. Oxidative burst and degranulation are bactericidal mechanisms used by heterophils to kill pathogens and were used in this study as indicators of heterophil function. We found that each of the 10 "generally recognized as safe" probiotic isolates (designated G1 to G11) tested in vitro were capable of increasing (P < 0.05) heterophil oxidative burst and degranulation when compared with unstimulated controls. Bacillus subtilis (G3), Lactococcus lactis lactis (G6), and Lactobacillus acidophilus (G8) isolates were determined to elicit the greatest heterophil response in vitro and were subsequently fed to chicks. Phosphate-buffered saline or 1 of these 3 probiotic isolates (approximately 2.5 x 10(8) cfu/chick; 50 chicks/treatment) resuspended in PBS was administered by oral gavage on the day of hatch. Heterophils were isolated from chicks from each of these 4 treatment groups 24 h posttreatment. Significant increases in heterophil degranulation and oxidative burst were observed with the G3-, G6-, and G8-treated chicks when compared with heterophils isolated from birds with no probiotic treatment. These data suggest that probiotic bacteria can significantly improve heterophil oxidative burst and degranulation in broilers. To our knowledge, this is the first study demonstrating a relationship between probiotics and avian heterophil function.

Effect of oral administration of bismuth compounds on Campylobacter colonization in broilers.

Bismuth compounds have been used since the 18th century to treat gastrointestinal ailments in man. Colloidal bismuth subcitrate (De-Nol) is currently used in combination with antibiotics to reduce enteric Helicobacter pylori colonization as a treatment of stomach ulcers. We investigated whether bismuth citrate or its parent compound, colloidal bismuth subcitrate, would reduce colonization of the closely related foodborne pathogen, Campylobacter jejuni in chickens. In 2 studies, birds were either fed 0, 50, or 200 ppm bismuth citrate or bismuth subcitrate (De-Nol) for 10 or 21 d and were orally challenged with 7 combined strains of C. jejuni (n = 6 birds/treatment). For both treatment groups, cecal Campylobacter colonization was reduced when birds were fed 200 ppm for 10 d but not 21 d. For the 50 ppm treatment group, only birds dosed with bismuth citrate for 21 d demonstrated any reduction in cecal Campylobacter concentrations when compared with controls. These data suggest that bismuth citrate and colloidal bismuth subcitrate may reduce cecal colonization by Campylobacter in broilers, but these effects are inconsistent.

Bacteriocins reduce Campylobacter colonization and alter gut morphology in turkey poults.

Campylobacter is a leading cause of food-borne illness in the United States. Recent evidence has demonstrated that bacteriocins produced by Bacillus circulans and Paenibacillus polymyxa reduce cecal Campylobacter colonization in broiler chickens infected with Campylobacter jejuni. As Campylobacter coli is the most prevalent Campylobacter isolate recovered in turkeys, the objectives of the present study were to evaluate the efficacy of these bacteriocins against C. coli colonization and their influence on the gastrointestinal architecture of young turkeys. In 3 separate trials, a total of 135 day-of-hatch poults (n = 45/trial) were orally challenged on d 3 with approximately 10(6) cfu of a mixture of 3 C. coli isolates. Immediately before bacteriocin treatment (d 10), cecal Campylobacter concentrations averaged 1.1 x 10(7) cfu/ g of cecal contents (n = 15/trial). On d 10 to 12 posthatch, 2 bacteriocin treatment groups were given free access to feed supplemented with purified, microencapsulated bacteriocins, whereas the positive control treatment group had access to untreated feed (n = 10/treatment group per trial). At the end of the 3-d dosing period, ceca and duodenal loops were collected for analysis. In each of the 3 separate trials, treatment with bacteriocin eliminated detectable ceca Campylobacter concentrations (detection limit, 1 x 10(2) cfu/g of cecal contents) vs. controls (1.0 x 106 cfu of Campylobacter/g of cecal contents). Duodenum crypt depth and goblet cell numbers were also reduced in turkeys treated with either bacteriocin vs. controls (P < 0.05). The dynamic reduction in crypt depth and goblet cell density in turkeys dosed with bacteriocin may provide clues to how bacteriocins inhibit enteric Campylobacter.

Hypobaric hypoxia in ascites resistant and susceptible broiler genetic lines influences gut morphology.

Genetic selection based on rapid growth rates, improved feed conversion, and increased body weights has led to a predisposition to ascites in broiler populations. Sire-family selection was applied to a commercial elite line to produce divergent lines of ascites-resistant (RES) and ascites-susceptible (SUS) broilers by the 8th generation. One objective of this research was to determine the effects of hypobaric hypoxia on gut morphology in these genetic lines. In two separate trials, pedigree broiler chickens were randomly assigned to cages in a hypobaric chamber (simulated 2,900 m above sea level) or a matching local altitude chamber (390 m above sea level). Ascites incidence was characterized by heart enlargement and fluid accumulation in the abdominal cavity. At the end of the study on d 42, all surviving birds were killed and evaluated for the presence of ascites and 2-cm sections from the duodenum and lower ileum were collected from 5 chickens per line, per altitude for each trial for morphometric analysis. At a high altitude, ascites incidence was lower in the RES line (20.9 and 3.7%) than in the SUS line (86.4 and 66.9%, Trials 1 and 2, respectively). No ascites was observed at a local altitude. Under hypoxic conditions, duodenum villus surface area was higher (P < 0.05) in the RES line (181.3 +/- 16.8 and 219 +/- 10.9 microm) compared with the SUS line (130.1 +/- 10.5 and 134.3 +/- 9.3 microm; Trials 1 and 2, respectively). No differences in ileum villus morphology were observed for any of the parameters measured. The reduced surface area in the duodenum of birds selected for ascites susceptibility suggests reduced enteric function and may provide clues as to why these birds have increased incidence of ascites.

Campylobacter susceptibility to ciprofloxacin and corresponding fluoroquinolone concentrations within the gastrointestinal tracts of chickens.

AIMS: This study evaluated the relationship between Campylobacter susceptibility and enteric fluoroquinolone concentrations in chickens treated with different doses of enrofloxacin. METHODS AND RESULTS: All chickens were challenged with seven fluoroquinolone sensitive Campylobacter jejuni (6.6 x 10(6) CFU per bird) at 2 weeks posthatch. At 26 days of age chickens were treated with 0 (n = 29 birds), 25 mg ml(-1) enrofloxacin (Baytril, Bayer Corp., Shawnee Mission, KS, USA) for 3 days (n = 45 birds) or 50 mg ml(-1) enrofloxacin for 7 days (n = 65 birds) in the drinking water. The crop, upper ileum, lower ileum, ceca and colon contents were collected from both enrofloxacin treatment groups (n = 5 birds per day per treatment group) and nonmedicated controls. The minimum inhibitory concentration (MIC) of ciprofloxacin for Campylobacter increased for isolates from both treatment groups within the first day of dosing and the daily average ranged from 1.4 to 6.5 microg ml(-1) throughout the study. Although enteric fluoroquinolone concentrations were higher (P < 0.05) in birds dosed with 50 mg ml(-1)vs 25 mg ml(-1) enrofloxacin, there were no differences between the isolates collected from these groups for MIC values. CONCLUSION: These data indicate, for the doses used, differences in gut fluoroquinolone concentrations do not produce isolates of Campylobacter with differing susceptibility to ciprofloxacin. SIGNIFICANCE AND IMPACT OF THE STUDY: Using the manufacturers lowest, shortest duration dose vs the highest, longest duration dose of enrofloxacin did not change Campylobacter susceptibility to ciprofloxacin. However, ciprofloxacin MIC values for Campylobacter determined in this study were lower than previously reported.

Effect of prebiotic on gut development and ascites incidence of broilers reared in a hypoxic environment.

Modern broilers have been genetically selected for an increased growth rate and improved feed conversion, but they are also more susceptible to ascites. Ascites occurs when there is an imbalance between available oxygen and the oxygen demand of the broiler. We hypothesized that promoting neonatal gut development with a prebiotic, such as Aspergillus meal (Prebiotic-AM), would enhance gut efficiency, decrease the oxygen demand of the gut, and reduce ascites incidence. In this study, we compared the effect of Prebiotic-AM on ascites incidence and gut development in commercial broilers reared at a local altitude (390 m above sea level) and a simulated high altitude (2,900 m above sea level). Half of the birds received a National Research Council recommended corn-soybean ration, and the other half received the same ration supplemented with 0.2% Prebiotic-AM. These 2 groups were further divided into a local altitude group and a simulated high altitude group for a total of 4 treatment combinations. Tissues were collected on d 1, 3, 7, 14, and 21 from the duodenum and lower ileum and placed in 10% buffered formalin for morphometric analysis. At a simulated high altitude, ascites incidence was 68% for birds fed the Prebiotic-AM supplement compared with 92% ascites incidence in birds given the control feed. The simulated high altitude decreased (P < 0.05) gut development, but prebiotic-treated birds reared in hypoxic conditions had similar gut development to control birds reared at local altitude. These data suggest that a feed ration supplemented with Prebiotic-AM may reduce the effect of hypoxia on broiler gut development and ascites incidence.

Purified beta-glucan as an abiotic feed additive up-regulates the innate immune response in immature chickens against Salmonella enterica serovar Enteritidis.

Functionally, the innate immune system of immature chickens is inefficient during the first week posthatch. This immunological inefficiency enables pathogens such as Salmonella enterica serovar Enteritidis (SE) to invade and colonize the visceral organs of immature chickens. The objective of this study was to evaluate the effect of purified beta-glucan as an immunomodulator of the innate immune response. beta-glucan, as a feed additive, significantly provided protection against SE organ invasion in young chickens (P<0.05). The functional efficiency of heterophils isolated from neonatal chickens fed a beta-glucan ration was significantly (P<0.05) up-regulated when compared to heterophils isolated from chickens fed a control ration as determined with an array of functional assays. Phagocytosis, bactericidal killing, and oxidative burst were significantly increased in heterophils isolated from chickens fed the purified beta-glucan ration (P<0.05). To our knowledge, this is the first report of a purified beta-glucan feed additive significantly decreasing the incidence of SE organ invasion in immature chickens and up-regulating the functional abilities of heterophils isolated from immature chickens against an invading pathogen, SE.

Idiopathic benign biliary strictures in surgically resected patients with presumed cholangiocarcinoma.

OBJECTIVE: Distinguishing between malignant and benign biliary strictures remains problematic. The aim of this study was to compare and contrast the clinical features of patients with benign and malignant biliary strictures. METHODS: Medical records of patients who underwent surgical resection for presumed cholangiocarcinoma were reviewed. Immunohistochemistry for hypoxia inducible factor-1-alpha (HIF-1-alpha) was performed on all bile ductule samples. RESULTS: Twelve patients with benign strictures (group I) were compared to 26 patients with cholangiocarcinoma (group II). Group I was predominantly female (ratio 2: 1), (p<0.01), whereas the gender ratio was 1: 1 in patients in group II. Bismuth-Corlette type strictures in group I were more likely to be type I/II, whereas type III strictures predominated in group II. The CA 19-9 was <100 U/ml in 6 and >100 U/ml in 1 patient of group I and <100 in 13 and >100 in 11 patients in group II. Half of the patients in group I had positive immunoreactivity for HIF-1-alpha in bile ductules. CONCLUSION: Benign biliary strictures masquerading as cholangiocarcinomas occur more often in women, are less often Bismuth-Corlette type III, have serum CA 19-9 values <100 U/ml, and hypoxia may play a role in a subset of these strictures.

Cystic neoplasms of the pancreas: benign to malignant epithelial neoplasms.

Clinical presentation and state-of-the-art imaging permit the differentiation of most cystic pancreatic neoplasms not only from other cystic pancreatic disorders but also from one another. The differentiation of serous cystic lesions from the mucinous neoplasms (cystadenoma or carcinoma and IPMT) is crucial because of the radically different biological characteristics of these two neoplasms. Although mucinous cystic neoplasms should be resected because of their premalignant or overtly malignant tendency, most patients with serous neoplasms require no operative intervention unless they are symptomatic. IPMT is best treated by a total pancreatectomy, although lesser subtotal resections should be strongly considered depending on patient age, medical comorbidity, and psychosocial situations.