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Chlamydia psittaci is a zoonotic agent of systemic wasting disease in birds and atypical pneumonia in mammalians including humans, constituting a public health risk. A rapid diagnostic assay would be beneficial in screening C. psittaci in the field. In this study, we developed a probe-based recombinase polymerase amplification (RPA) assay for the rapid detection of C. psittaci. The specific primer pairs and probe targeting the conserved region of the outer membrane protein A gene were designed and applied to the real-time real-time RPA assay. The test can be performed at 39°C for 20 min using a portable device, with sensitivities approaching 100 copies of DNA molecules per reaction, with no cross-reaction with other pathogens. The clinical performance of the RPA assay was evaluated in an outbreak of C. psittaci and has high accuracy levels in field applications. The epidemic C. psittaci strains were classed into 2 genotypes: A and C. Collectively, this study offers a promising approach in screening for C. psittaci both in a laboratory setting and in field settings, and RPA can be used as an effective clinical test to monitor outbreaks in domestic fowl populations.

Emission of atmospheric ammonia (NH3) is an environmental challenge because of its harmful effects on humans and animals including birds. Among all organisms, NH3 is highly sensitive to birds. Autophagy plays a critical role in Bursa of fabricius (BF)-mediated immune responses against various hazardous substances. Therefore, we designed our work to demonstrate whether NH3 can induce autophagy in broiler chicken BF. In this study, the downregulated levels of mammalian target of rapamycin and light chain-3 (LC-Ⅰ), as well as the upregulated levels of phosphate and tensin homology (PTEN), protein kinase B (AKT), autophagy related-5, light chain-3 (LC3-Ⅱ), Becline-1, and Dynein, were found. Our results of transmission electron microscopy displayed signs of autophagosomes/autophagic lysosomes, and immunofluorescence assay displayed that NH3 exposure reduced the relative amount of CD8+ B-lymphocyte in chicken BF. Exposure of NH3 led to energy metabolism disturbance by decreasing mRNA levels of glucose metabolism factors aconitase-2, hexokinase-1, hexokinase-2, lactate dehydrogenase-A, lactate dehydrogenase-B, pyruvate kinase, phosphofructokinase and succinate dehydrogenase complex unit-B, and adenosine triphosphates (ATPase) activities (Na+/K+ ATPase, Ca2+ ATPase, Mg2+ ATPase, and Ca/Mg2+ ATPase). Moreover, phosphate and tensin homology was found as target gene of microRNA-99a-3p which confirmed that high concentration of NH3 caused autophagy in chicken BF. In summary, these findings suggested that ammonia induced autophagy via miR-99a-3p, the reduction of ATPase activity, and the alteration of autophagy-related factors, and energy metabolism mediation in BF. Our findings provide information to assess the harmful effects of NH3 on chicken and clues for human health pathophysiology.

Intestinal mucosa is the largest immune organ in animals, and its immune function is directly related to the resistance against various diseases. Taishan Pinus massoniana pollen polysaccharides (TPPPS) have been recognized as an effective vaccine adjuvant and potential immune enhancer against viral infections. However, little is known about their direct immune-enhancing activity on intestinal mucosa. In this study, we extracted the polysaccharides from Taishan masson pine pollen to investigate its promotive effect on intestinal mucosal immunity. A total of 120 1-day-old chickens were divided into 4 groups and inoculated with PBS or 3 different doses of TPPPS (10 mg/mL, 20 mg/mL, and 40 mg/mL), respectively. Feces, intestinal specimens, and serum samples were collected from the chickens at 7, 14, and 21 d after inoculation. The antibodies in serum, mucosal secretion of IgA, structure of intestinal villi, and expressions of cytokine genes and mucosal immune-related genes in the chickens were all significantly improved by TPPPS treatments. At 21 d after inoculation following the challenge of Newcastle disease virus, the chickens inoculated with 20 and 40 mg/mL TPPPS exhibited decreased weight loss and reduced intestinal pathologic damage and viral loads in the intestine. In summary, our results demonstrate that TPPPS can enhance mucosal immunity and promote intestinal villi development. This study has established the foundation for the development of novel immune-enhancing agent with immune-regulatory effects on intestinal mucosa.

Pigeon paramyxovirus type 1 (PPMV-1) is a globally distributed, virulent member of the avian paramyxovirus type-1. The PPMV-1–associated disease poses a great threat to the pigeon industry. The innate immune response is crucial for antiviral infections and revealing the pathogenic mechanisms of PPMV-1. In this study, we evaluated the pathogenicity of a PPMV-1 strain LHLJ/110822 in one-month-old domestic pigeons, as well as the host immune responses in PPMV-1–infected pigeons. We observed typically clinical sign in infected pigeons by 3 dpi. The morbidity rate and the mortality in pigeons inoculated with the PPMV-1 strain were up to 100% and 30%, respectively. The virus could replicate in all of the examined tissues, namely trachea, lung, liver, spleen, and bursa of Fabricius. In addition, the infected pigeons had developed anti-PPMV-1 antibodies as early as 8 dpi; and the antibody level increased over the time in this study. The expression level of toll-like receptor (TLR) 2, TLR3 TLR15, IFN-γ, and IL-6 were significantly upregulated by the PPMV-1 infection in some tissues of pigeons. By contrast, PPMV-1 infection results in downregulation of IL-18 expression in most of investigated tissues except for bursa of Fabricius in this study. The current results confirmed that this virus could replicate in pigeons and induce host immune responses, then leading to produce serum antibody titers. Meanwhile, the PPMV-1 infection induces strong innate immune responses and intense inflammatory responses at early stage in pigeon which may associate with the viral pathogenesis.

H7N7 avian influenza virus (AIV) can divided into low-pathogenic AIV and high-pathogenic AIV groups. It has been shown to infect humans and animals. Its prevalence state in wild birds in China remains largely unclear. In this study, a new strain of H7N7 AIV, designated CM1216, isolated from wild birds in Shanghai, China, was characterized. Phylogenetic and nucleotide sequence analyses of CM1216 revealed that HA, NA, PB1, NP, and M genes shared the highest nucleotide identity with the Japan H7 subtype AIV circulated in 2019; the PB2 and PA genes shared the highest nucleotide identity with the Korea H7 subtype AIV circulated in wild birds in 2018, while NS gene of CM1216 was 98.93% identical to that of the duck AIV circulating in Bangladesh, and they all belong to the Eurasian lineage. A Bayesian phylogenetic reconstruction of the 2 surface genes of CM1216 showed that multiple reassortments might have occurred in 2015. Mutations were found in HA (A135 T, T136S, and T160 A [H3 numbering]), M1 (N30D and T215 A), NS1 (P42S and D97 E), PB2 (R389 K), and PA (N383D) proteins; these mutations have been shown to be related to mammalian adaptation and changes in virulence of AIVs. Infection studies demonstrated that CM1216 could infect mice and cause symptoms characteristic of influenza virus infection and proliferate in the lungs without prior adaption. This study demonstrates the need for routine surveillance of AIVs in wild birds and detection of their evolution to become a virus with high pathogenicity and ability to infect humans.

Povidone-iodine (Polidine) is a synthetic broad-spectrum antiseptic and being applied topically to treat wounds and prevent their infection. It is however used by poultry farmers, field veterinarians, and other animal health workers with the claim that it is effective for treatment of infectious bursal disease when administered orally. Hence, an acute oral toxicity study was conducted to ascertain its safety profile. Ten cockerel chicks were randomly selected and divided into 2 groups of 5 chicks per group. One group served as the negative control, whereas the other group was administered povidone-iodine at a dose of 2,000 mg/kg of BW orally. The blood sample was collected at the end of the study to determine changes in hematological and biochemical parameters. In addition, vital organs were also harvested and preserved for histopathological examinations. The result showed that the median lethal dose (LD50) of the povidone-iodine is higher than 2,000 mg/kg of BW in cockerels. There were no significant changes in the hematological parameters measured. Biochemical evaluation (renal and liver function test) showed an increase in aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels after administration of povidone-iodine. The study indicated that the LD50 of povidone-iodine is higher than 2,000 mg/kg of BW of cockerels, and there were increases in urinary and liver enzymes at this dose.

Despite high global vaccination coverage, Newcastle disease (ND) remains a constant threat to poultry producers owing to low antibody levels. Given the respiratory mucosa is the important site for Newcastle disease virus (NDV) vaccination, enhancing respiratory mucosal immunity may help control ND. Our previous study showed that mulberry leaf polysaccharide (MLP) is very promising in delivering a robust balanced immune response, but the effects of it on respiratory immunity in chicks are unknown. In this study, we evaluated the potential of MLP to activate respiratory mucosal immunity and revealed the possible mechanism of MLP as an immunopotentiator for ND vaccines. Chicks were randomly divided into 5 groups: blank control, vaccination control (VC), and low-, middle-, and high-dose MLP (MLP-L, MLP-M, and MLP-H) (n = 30). The serum results of humoral and cell-mediated immune responses showed significant increases in NDV hemagglutination inhibition antibody titer, IgG and IgA antibody levels, and the T-lymphocyte population in the MLP-M group compared with the VC group. Validation of results also indicated remarkable increases in tracheal antibody-mediated immunity and a mucosal immune response in the MLP-M group. Furthermore, the upregulation of TLR7 revealed a possible mechanism. Our findings provided evidence to consider MLP as a potential mucosal vaccine adjuvant candidate against ND in chickens.

The immunomodulatory effect of Acanthopanax senticosus polysaccharide (ASPS) on immunosuppressed chickens induced by cyclophosphamide (Cy) was observed in this study. Four hundred 7-day-old chickens were randomly divided into 4 groups: vaccinated control group (VC group), Cy-challenged control group (Cy group), Cy-challenged + low-dose ASPS group (ASPSL + Cy group), and Cy-challenged + high-dose ASPS group (ASPSH + Cy group). All groups except the VC group were injected with Cy at a dose of 80 mg/kg/day of BW for 3 successive days to induce immunosuppression. At the age of 10 d, the ASPSL + Cy group and ASPSH + Cy group were intramuscularly injected with 0.2 mL of ASPS at the dose of 100 and 200 mg/mL/day, respectively, once a day for 3 successive days. The Cy group was injected with saline solution in the same way as the 2 ASPS groups. At the age of 14 d, the chickens were vaccinated with Newcastle disease (ND) vaccine in all groups. On day 7, 14, 21, and 28 after the vaccination, BW, lymphocyte proliferation, the serum antibody titers of the ND vaccine, the proportion of CD4+ and CD8+ T lymphocytes, and the concentrations of interferon gamma and IL-2 were determined. The results showed that chickens were injected with Cy at a dose of 80 mg/kg of BW for 3 d displayed lower immune responses than the control group, indicating that the immunosuppressive model was successfully established. At most time points, both high and low doses of ASPS could significantly promote lymphocyte proliferation; enhance BW, antibody titers, and the proportion of CD4+ and CD8+ T lymphocytes; and raised the concentrations of interferon gamma and IL-2 in Cy-treated chickens compared with those in the Cy control group (P < 0.05). These results indicated that ASPS could resist immunosuppression induced by Cy and may be a new-type immune adjuvant to improve vaccination in normal and immunosuppressed chickens.

This study aimed to investigate an experimental procedure of coccidial challenge in battery cages and the anticoccidial effect of a bioactive olive pomace extract from Olea europaea (OE) in broiler chickens. To this end, four hundred 1-day-old male chicks were randomly assigned to 5 experimental treatments (10 cages/treatment; 8 birds/cage). One group was fed the control diet without any additives and not challenged (NCU). The other 4 groups were challenged and fed the control diet with no additives (NCC) or supplemented with 500 ppm of coccidiostat or with 500 or 1,500 ppm of OE. At 0, 7, and 14 d, all challenged birds, except the NCC group, were orally gavaged with a live Eimeria spp. oocyst vaccine at 1x, 4x, and 16x of the manufacturer's recommended dose, respectively. Feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) were determined at 7, 14, 20, and 28 d. At 20 d of age, 1 bird per cage was euthanized to analyze duodenum and jejunum morphology, ileal mucosa gene expression, and plasma cytokine, alpha-1-acid glycoprotein, and carotenoid (CAR) concentrations. Coccidial vaccine challenge lowered BW (P

Duck Tembusu virus (DTMUV), a mosquito-borne flavivirus, has been identified as a causative agent of an emerging viral disease in ducks, causing significant economic losses to the duck-producing industry. In Thailand, DTMUV has been detected sporadically in ducks since the first report in 2013. However, information on the patterns of DTMUV infection in ducks in Thailand is limited. In this study, a serological survey of DTMUV on ducks raised in farming and free-grazing systems was conducted during 2015-2016. Blood samples of farm ducks (n = 160) and free-grazing ducks (n = 240) were collected in the summer, rainy, and winter seasons during 2015-2016 and tested for DTMUV infection. Our results showed that DTMUV infection in ducks in Thailand occurred all year-round; however, the patterns of DTMUV infection varied between 2 duck-raising systems. Significant seasonal pattern was found in free-grazing ducks, whereas no seasonality was observed in farm ducks. Notably, DTMUV infection in ducks in Thailand was highest in the winter season. In conclusion, our data indicate distinct patterns of DTMUV infection between farm and free-grazing ducks, and the year-round circulation of DTMUV in ducks in Thailand, with peaks in the winter season. This information will help reduce the risk of DTMUV transmission through prevention and control strategies focusing on the peak period. Routine surveillance of DTMUV in ducks is essential for early detection of DTMUV allowing the implementation of control measures in a timely manner.

The rapid renewal and repair of the intestinal mucosa are based on intestinal stem cells (ISC), which are located at the crypt bottom. Paneth cells are an essential component in the crypt, which served as the niche for ISC development. However, in the chicken, how the function of Paneth cells changes during intestinal inflammation is unclear and is the key to understand the mechanism of mucosal repair. In the present study, 36 HyLine White chickens (7 d of age, n = 6) were randomly divided into 1 control and 5 lipopolysaccharide (LPS) injection groups. The chickens were injected (i.p.) with PBS in the control group, however, were injected (i.p.) with LPS (10 mg/kg BW) in the LPS injection groups, which would be sampled at 5 time points (1 h postinjection [hpi], 2 hpi, 4 hpi, 6 hpi, and 8 hpi). Results showed that tumor necrosis factor-α mRNA transcription in duodenal tissue increased gradually since 1 hpi, peaked at 4 hpi, and then reduced remarkably, indicating that 4 hpi of LPS was the early stage of intestinal inflammation. Meanwhile, the MUC2 expression in duodenal tissue was dramatically reduced since 1 hpi of LPS. The ISC marker, Lgr5 and Bmi1, in the duodenal crypt were reduced from 1 hpi to 4 hpi and elevated later. Accordingly, the hydroethidine staining showed that the reactive oxygen species level, which drives the differentiation of ISC, in the duodenal crypt reduced obviously at 1 hpi and recovered gradually since 4 hpi. The analysis of Paneth cells showed that many swollen mitochondria appeared in Paneth cells at 4 hpi of LPS. Meanwhile, the Lysozyme transcription in the duodenal crypt was substantially decreased since 1 hpi of LPS. However, the Wnt3a and Dll1 in duodenal crypt decreased at 1 hpi of LPS, then increased gradually. In conclusion, Paneth cells were impaired at the early stage of intestinal inflammation, then recovered rapidly. Thus, the ISC activity was reduced at first and recovery soon.

Astroviruses are a common cause of gastroenteritis in humans and animals. They are also associated with extraintestinal infections, including hepatitis in ducklings, nephritis in chickens, as well as fatal meningitis and encephalitis in humans and other mammals. Since 2014, outbreaks of disease characterized by visceral gout and swelling of kidneys have been reported in goslings and ducklings in China, with the causative agent revealed to be a novel avian astrovirus designated goose astrovirus (GoAstV). In the present study, this novel gout-associated GoAstV was identified in diseased goslings from 2 farms in Hunan province, China. Three genomes were successfully sequenced and analyzed and were shown to have high identities of 99.7 to 99.8% between each other, with some specific amino acid alterations revealed in open reading frame 2 when compared with other gout-associated GoAstVs. Two strains were further efficiently isolated in the DF-1 chicken fibroblast cell line with high virus titers of 1011 viral genomic copies per mL of culture media. A pilot virus challenge study using GoAstV in chickens demonstrated that this virus can cause clinical visceral gout in chickens, indicating its ability to cross the species barrier. Based on the phylogenetic analyses of capsid sequences, the identified GoAstVs were proposed to be classified into 2 genotypes, GoAstV1 and GoAstV2, and the novel gout-associated GoAstVs were all clustered in GoAstV2. Further Bayesian inference analyses indicated a nucleotide substitution rate of 1.46 × 10−3 substitutions/site/year for avian astrovirus based on open reading frame 2 sequences, and the time to the most recent common ancestor of GoAstVs was estimated to be around 2011. This is the first report to confirm GoAstV can infect chickens while also providing an estimation of the evolutionary rates of Avastroviruses.

Phosvitin (PV) from egg yolk is an excellent substrate for the production of phosphopeptides, which have a strong calcium chelating capacity and promoting calcium absorption and bone mineralization. This study investigated the effect of PV hydrolysates produced using a effective preparation method (high temperature (121°C) and mild pressure (0.1 MPa), HTMP) or HTMP pretreatment and trypsin hydrolysis combination (HTMP-PV18) on the physiology of an osteoblast MC3T3-E1 cells line. The proliferation, apoptosis, and differentiation of MC3T3-E1 cells were analyzed using the CCK-8, flow cytometry, and RT-PCR reactions, respectively. Both the HTMP-PV and HTMP-PV18 increased the proliferation, and inhibited the apoptosis of MC3T3-E1 cells significantly. The HTMP-PV increased the proliferation of MC3T3-E1 cells by 147.12 ± 2.11% and the HTMP-PV18 by 136.43 ± 4.51%. In addition, the HTMP-PV and HTMP-PV18 effectively promoted the expression of genes related to the OPG/RANKL signaling channel during cell differentiation. This indicated that both the HTMP-PV and HTMP-PV18 have the potential to promote bone mineralization by improving the proliferation and differentiation of osteoblastic cells.

The aim of this study is to determine if enteric viruses are the cause of diarrhea in broiler flocks in Jordan. Intestinal content samples were collected from 101 broiler flocks from several regions of Jordan to detect the presence of astrovirus, coronavirus, reovirus, and rotavirus, by using reverse transcriptase polymerase chain reaction (RT-PCR). Forty-six of these flocks were clinically healthy with no enteric disease, and the other 55 flocks were clinically suffering from diarrhea. The samples were collected between 5 and 16 d of age. The results show that 79% of total 101 flocks tested were infected with one or more of the above enteric viruses. Coronavirus was the most common virus, detected in 56.4% of these flocks, with astrovirus in 29.7% of the flocks, and rotavirus (9.9%) and reovirus (5.6%) being the least common. None of these flocks were found to be infected with all four viruses, but one of the flocks was found to be infected with astrovirus, coronavirus, and rotavirus simultaneously. Individual infection was noted with astrovirus, coronavirus and rotavirus but not with reovirus, whereas all flocks infected with reovirus were also infected with coronavirus. There was no statistical evidence to link these viruses as the main cause of diarrhea in the flocks tested. This is the first study in Jordan to detect all of these viruses and to correlate their presence with diarrhea in chicken flocks.

Commercial poultry is an important agricultural industry worldwide. Although dense living conditions and large flocks increase meat and egg production, they also increase the risk of disease outbreaks and zoonoses. Current pathogen identification methods mostly rely on culture-dependent techniques and, therefore, are limited to a very small number of bacteria present in the environment. Next Generation Sequencing allows for culture-independent characterization of lower respiratory microbiome of birds including the identification of novel commensals and potentially emerging pathogens. In this study, we collected tracheo-bronchoalveolar lavage of 14 birds raised at 3 different farms in the Punjab province of Pakistan. To characterize the lower respiratory microbiome of these birds, we sequenced hyper-variable regions of the 16S ribosomal subunit gene. Although dominated by bacteria belonging to a small number of taxonomic classifications, the lower respiratory microbiome from each farm was far more diverse and novel than previously known. The differences in microbiome among farms suggest that inter-farm differences affect the microbiome of birds more than breed, geographic location, or management system. The presence of potential and known pathogens in genetically similar specialty breeds of chickens kept at unnaturally high densities and under variable conditions presents an extraordinary opportunity for the selection of highly pathogenic bacteria. In some instances, opportunistic respiratory pathogens were observed in apparently healthy birds. Understanding and monitoring the respiratory microbiome of such populations may allow the early detection of future disease threats.

Natural antibody (NAb) levels and survival rates were evaluated in 4 breeds of laying hens in Ethiopia: indigenous, improved indigenous, exotic layer, and crossbred. Titers of NAb isotypes IgG and IgM binding keyhole limpet hemocyanin (KLH) in serum were measured at 20, 26, 35, and 45 wk age. Repeated-measure ANOVA showed that IgG and IgM levels vary with time within each breed (P < 0.05). Indigenous chickens had significantly (P < 0.05) higher NAb levels at all ages. The Cox proportional hazard analysis showed increased hazard with increased levels of NAbs in the exotic layers (P < 0.05). However, the reduced hazards with increased levels of NAbs were not significant in the improved indigenous and crossbred chickens. Indigenous chickens showed increased hazard with increasing levels of NAb (P > 0.05). We concluded that not only the NAb levels but also the effect of Nabs on survival vary between indigenous and improved breeds. The results indicate that NAb levels are associated with survival in elite (improved) breeds, but are associated with increased hazard in indigenous chickens.

Atherosclerosis is a major contributor to the overall United States mortality rate, primarily in the form of heart attacks and stroke. Unlike the human disease, which is believed to be multifactorial, pigeon atherosclerosis is due to a single gene autosomal recessive trait. The White Carneau (WC-As) strain develops atherosclerotic plaques without the presence of known environmental risk factors such as diet and classic predictors such as blood pressure or blood cholesterol levels. With similar parameters, the Show Racer (SR-Ar) is resistant to plaque development. Thiazolidinediones, including rosiglitazone, activate the peroxisome proliferator-activated receptor gamma (PPARγ) raising cellular sensitivity to insulin. The effect of rosiglitazone was evaluated in aortic smooth muscle cells (SMC) from these 2 pigeon breeds. Primary SMC cultures were prepared from WC-As and SR-Ar squabs. Cell monolayers, which achieved confluence in 7 d, were treated with 0 or 4 µM rosiglitazone for 24 h. Cellular lipid accumulation was evaluated by oil red O staining. Control WC-As cells had significantly higher vacuole scores and lipid content than did the SR-Ar control cells. Rosiglitazone treatment decreased WC-As lipid vacuoles significantly compared with the control cells. On the other hand, lipid vacuoles in the treated and untreated SR-Ar cells did not differ significantly. The effect of rosiglitazone on WC-As SMC gene expression was compared with control SMC using representational difference analysis. Significant transcript increases were found for caveolin and RNA binding motif in the control cells compared with the rosiglitazone-treated cells as well as cytochrome p450 family 17 subfamily A polypeptide 1 (CYP171A) in the rosiglitazone-treated cells compared with the control cells. Although rosiglitazone was selected for these experiments because of its role as a PPARγ agonist, it appears that the drug also tempers c-myc expression, as genes related to this second transcription factor were differentially expressed. Both PPARγ and c-myc appear to affect WC-As SMC gene expression, which may relate to disease development, progression, or both.

Experimental and epidemiological evidence suggests that primary infection of Salmonella is by the oral-fecal route for poultry. However, the airborne transmission of Salmonella and similar enteric zoonotic pathogens has been historically neglected. Increasing evidence of Salmonella bioaerosol generation in production facilities and studies suggesting the vulnerabilities of the avian respiratory architecture together have indicated the possibility of the respiratory system being a potential portal of entry for Salmonella in poultry. Presently, we evaluated this hypothesis through intratracheal (IT) administration of Salmonella Enteritidis and Salmonella Typhimurium, as separate challenges, in a total of 4 independent trials, followed by enumeration of cfu recovery in ceca-cecal tonsils and recovery incidence in liver and spleen. In all trials, both Salmonella Enteritidis and Salmonella Typhimurium, challenged IT colonized cecae to a similar or greater extent than oral administration at identical challenge levels. In most trials, chickens cultured for cfu enumeration from IT-challenged chicks at same dose as orally challenged, resulted in an increase of 1.5 log higher Salmonella Enteritidis from ceca-cecal tonsils and a much lower dose IT of Salmonella Enteritidis could colonize ceca to the same extent than a higher oral challenge. This trend of increased cecal colonization due to IT challenge was observed with all trails involving week-old birds (experiment 2 and 3), which are widely considered to be more difficult to infect via the oral route. Liver-spleen incidence data showed 33% of liver and spleen samples to be positive for Salmonella Enteritidis administered IT (10(6) cfu/chick), compared with 0% when administered orally (experiment 2, trial 1). Collectively, these data suggest that the respiratory tract may be a largely overlooked portal of entry for Salmonella infections in chickens.

Poult enteritis complex has been associated with enteritis and reduction in growth rates in commercial turkeys worldwide. Intestinal samples from 76 turkey flocks from different Brazilian states affected or not with intestinal disorders were evaluated for the presence of adenovirus groups 1 and 2 (TAV), astrovirus types 1 and 2 (TAstV-1 and TAstV-2), turkey coronavirus (TCoV), reovirus, rotavirus, and avian nephritis virus (ANV) using PCR. The percentage of positive samples was categorized according to the geographic origin, age of the flocks, and presence of clinical signs of intestinal disease. The percentage of samples that were positive for at least one virus was 93.4%, whereas the percentage of samples that were positive for more than one virus was 69.7%. An average of 3.20 viruses per sample was detected in turkeys in the growing phase of the production cycle (1 to 4 wk of age). The TAstV-1 and TCoV were the most frequently observed viruses in growing phase turkeys and occurred simultaneously in 85% of these samples. In turkeys in the finishing phase of development (5 to 18 wk), a lower average number of viruses was observed (2.41), and the most frequent viruses isolated in these turkeys were TAstV-1 (57.1%) and rotavirus (51.8%). Overall, every virus was detected more frequently in growing phase turkeys than in finishing phase turkeys with the exception of TAV. Samples from flocks exhibiting clinical signs of intestinal disease showed a higher rate of positivity, and TAstV-1, TAstV-2, and TCoV were the most frequently occurring viruses in this cohort. Birds without clinical signs most frequently harbored TAstV-1 and rotavirus. Future studies should focus on the description and elucidation of the role of each virus, as well as the pathogenic and immunological implications of the different combinations of viruses in turkeys.

The immunoregulatory actions of conjugated linoleic acids (CLA) of relevance immunosuppression were investigated. To test the hypothesis that CLA ameliorate immunosuppression, we developed the immunosuppressive model of peripheral blood T lymphocytes in broiler chickens induced by cyclosporin A. Peripheral blood T lymphocytes of broiler chickens were cultured with media containing various concentrations (25, 50, 100, and 200 μmol/L) of c9, t11-CLA and t10, c12-CLA to investigate the effects of CLA isomers on peripheral blood T lymphocyte proliferation, interleukin-2, the activity of phospholipase C, and protein kinase C production. Results suggested that CLA alleviated the immunosuppression of T lymphocytes in broiler chickens exposed to cyclosporin A through increasing of peripheral blood T lymphocyte proliferation and interleukin-2. The 2 CLA isomers enhanced T lymphocyte proliferation at low concentration and inhibited T lymphocyte proliferation at high concentration. In addition, the effect of c9, t11-CLA was better than that of t10, c12-CLA. At the cellular level, the effects of CLA on the alleviation of immunosuppression in T lymphocytes are mainly attributable to increasing the signaling molecules, such as phospholipase C and protein kinase C.

Infectious bronchitis virus (IBV) infections cause great economic losses to the poultry industry worldwide, and the emergence of new variant strains complicates disease control. The present study investigated the genetic and protectotypic features of newly emerged Korean IBV strains. A phylogenetic analysis showed that several recent isolates formed 2 different clusters (new cluster 1 and 2), which were distinct from other preexisting clusters. New cluster 1 IBV strains represented recombinants between Korean nephropathogenic strain KM91 and the QXIBV strain. New cluster 2 IBV strains showed low amino acid homology (

Avian coronavirus infectious bronchitis virus (IBV) poses a major threat to the global poultry industry. New IBV geno- and serotypes are continually reported. However, information on IBV prevalence is not frequently addressed in these reports. This study reports on a viral surveillance program in Taiwan from 2005 to 2006 with sampling conducted in poultry slaughterhouses. The genetic features of the obtained field isolates were investigated using sequence analysis and SimPlot analysis. A 1-directional neutralization test was performed to examine the antigenic variations among the collected viruses. The selection pressures that may contribute to the evolution of Taiwan IBV during recent decades were assessed. The surveillance program revealed that 8 out of 47 flocks (17%) were IBV-infected, from which 13 IBV isolates were recovered. Based on the phylogenetic analysis of the S1 gene, 11 of 13 isolates (84.6%) clustered with Taiwan group I. One IBV isolate showed evidence of frequent recombination events with China-like IBV in the spike glycoprotein (S) gene. Another isolate demonstrated the incorporation of China-like and H120-like genome fragments within the S2 gene and the membrane protein (M) gene region, respectively. Some antigenic changes were found in the 1-directional neutralization test. However, no positive selection pressures were related to those variations in the S1 genes among Taiwan IBV. Based on our work, we suggest that sampling chickens in poultry slaughterhouses is an effective and valuable means of compiling viral prevalence data, particularly in situations where there is subclinical infection. Infectious bronchitis viruses from slaughtered chickens revealed intertypic genetic recombination and antigenic diversity.

Infectious bronchitis virus (IBV), the causative agent of infectious bronchitis, results in respiratory disease, nephritis, and poor egg production and quality in chicken. Antimicrobial peptides possess potent antimicrobial activities and are regarded as promising therapeutic alternatives in the fight against microorganisms. To assess the in vitro antiviral activity of swine intestine antimicrobial peptides (SIAMP) against IBV, 45 chick embryos were randomly assigned into 3 groups, 15 for each group. Embryos in group 1 were inoculated with IBV. Group 2 was inoculated with SIAMP-IBV intermixture. Group 3 was used as a control and inoculated with sterile PBS. Allantoic fluid was collected for hemagglutination titer assay. In addition, weight gain, mortality, and pathological changes for each group were recorded. The results showed that no distinct pathological changes were found in chick embryos after they were inoculated with SIAMP-IBV intermixture and the mortality was reduced remarkably compared with the IBV-infected group. Weight gain of embryos in the SIAMP-IBV intermixture group was significantly higher than the IBV-infected embryos (P < 0.01), which was also higher than the control group (P < 0.05). Furthermore, the hemagglutination titer in the SIAMP-IBV group was significantly lower than that in the IBV-infected group (P < 0.01). These results indicated that SIAMP can inhibit virus replication and reduce tissue injury caused by IBV.

This study was conducted to detect and characterize enteric viruses [rotavirus, turkey astrovirus-2 (TAstV-2), reovirus, and turkey coronavirus] from cases of poult enteritis syndrome (PES) in Minnesota turkeys. Of the intestinal contents collected from 43 PES cases, 25 were positive for rotavirus and 13 for small round viruses by electron microscopy (EM). Of the enteric virus-positive cases by EM (n = 27), 16 cases had rotavirus or small round viruses alone and the remaining 11 cases had both viruses. None of the cases were positive for reovirus or coronavirus by EM. However, with reverse transcription-PCR (RT-PCR), 40 cases (93%) were positive for rotavirus, 36 (84%) for TAstV-2, and 17 (40%) for reovirus. None of the cases were positive for turkey coronavirus by RT-PCR. The viruses from all cases were detected either alone or in combination of 2 or 3 by RT-PCR. Thus, 8 (19%) cases were positive for a single virus, whereas a combination of viruses was detected in the remaining 35 (81%) cases. The rota-TAstV-2 combination was the most predominant (n = 18 cases). Fifteen cases were positive for all 3 viruses. The rotaviruses had sequence homology of 89.8 to 100% with previously published sequences of turkey rotaviruses at the nucleotide level. The TAstV-2 had sequence homology of 84.6 to 98.7% with previously published TAstV-2, whereas reoviruses had sequence homology of 91.6 to 99.3% with previously published sequences of turkey reoviruses. Phylogenetic analysis revealed that rota- and reoviruses clustered in a single group, whereas TAstV-2 clustered in 2 different groups. In conclusion, a larger number of PES cases was positive for rotavirus, TAstV-2, and reovirus by RT-PCR than with EM. The presence of more than one virus and changes at the genetic level in a virus may affect the severity of PES in turkey flocks.

Poult enteritis syndrome (PES) is an infectious disease of turkey poults characterized by diarrhea, dullness, and depression. Five experiments were conducted to reproduce the disease in turkey poults using intestinal contents of PES-affected birds. In all experiments, poults at 14 d of age were divided into 4 groups and were orally given 2 mL of unfiltered supernatant, filtered supernatant, sediment dissolved in PBS, or PBS alone. Inocula in experiments 1, 3, and 5 consisted of intestinal contents from PES-affected birds of less than 2 wk of age, whereas those in experiments 2 and 4 consisted of intestinal contents from PES-affected birds of 4 to 6 wk of age. Poults in all groups were observed daily for clinical signs. The BW and microbiological criteria in experiments 1, 3, and 5 were evaluated at 5, 10, and 15 d postinoculation, whereas in experiments 2 and 4, these observations were made at 10 and 20 d postinoculation. Rotavirus, astrovirus, and Salmonella were present in all 5 inocula. Diarrhea and depression were the major signs in poults given PES material. Significant retardation of growth was observed in poults given any of the 3 PES materials, but this effect was more pronounced in poults given the sediment inoculum. Rotavirus, astrovirus, and Salmonella were detected in poults given PES material. In some cases, enterovirus was also detected. No major difference was noticed in experimental reproduction of PES when intestinal contents from different age birds were used as the inoculum.

Plexiform lesions form in the terminal pulmonary arterioles of human patients suffering from prolonged pulmonary arterial hypertension. Plexiform lesions also develop in broiler lungs, but lesion incidences are not strongly correlated with sustained pulmonary hypertension as reflected by right to total ventricular weight (RVTV) ratios. The present study was conducted to assess plexiform lesion incidences in broiler lines that have been divergently selected for susceptibility or resistance to pulmonary hypertension. Broilers from susceptible (SUS) and resistant (RES) lines were reared together and only clinically healthy (nonascitic, noncyanotic) individuals were evaluated to minimize potential line differences in cardiopulmonary hemodynamics. The objective was to determine if an innate genetic predisposition for plexogenic arteriopathy would be exposed in SUS broilers when compared with RES broilers in the absence of extreme differences in cardiopulmonary hemodynamics. Broilers up to 12 wk age from the SUS and RES lines had essentially equivalent BW, indices of cardiopulmonary function (left ventricle + septum weight, total ventricle weight, and RVTV ratios), and lung volumes within a sex. Average RVTV ratios for broilers from both lines were indicative of normal pulmonary arterial pressures at all ages sampled. Nevertheless, plexiform lesions were detected in SUS and RES broiler lungs immediately posthatch and thereafter at all ages sampled. Lesion incidences were consistently low and did not differ between the lines within any of the sampling ages. This evidence demonstrates that plexiform lesions develop extremely rapidly in broiler chicks, apparently without the prerequisite for vascular stress caused by severe, prolonged pulmonary arterial hypertension. No innate genetic predisposition for complex vascular lesion development appeared to exist in the SUS line when compared with the RES line.

One of the key benefits in using chickens for immunization is the high yield of antibodies obtainable. It is known that egg production decreases over time, while animal maintenance costs remain stable. It would, however, be desirable to keep hens as long as possible to obtain maximal amounts of antibodies. To identify a suitable length of time that animals can be kept and to optimize the cost:yield ratio, we monitored the number of eggs laid, the total amount of chicken IgY, and the specific antibody titer from individually prepared eggs over a 2-yr period. The plant toxin ricin and the Clostridium botulinum neurotoxins type A and B were used to immunize 4 chickens. The number of eggs laid in 2 yr was approximately 600 per hen (about 80% of the maximum egg number), yielding about 20 to 40 g of total IgY per hen. A stable antibody titer of 1:100,000 to 1:1,000,000, as measured by ELISA, was obtained following up to 11 injections of 10 to 20 μg of immobilized native toxin. Laying capacities were found to decrease, on average, from 7 eggs/wk at the point of first immunization to 2 eggs/wk after more than 2 yr. In parallel, the yield of total and specific IgY increased over time, so that the antibody recovery remained high, even after prolonged immunization times. Using purified IgY preparations, classical immunological assays such as ELISA and Western blotting were performed. Furthermore, the IgY showed neutralizing capacity when used to block the functional activity of the toxins both in vitro and in vivo. Analysis of the total IgY content over time demonstrated a complex biological oscillation (and the antigen-specific titer), with a shorter time period of around 7 d (circaseptan rhythm). In summary, we successfully immunized chickens with ricin and botulinum neurotoxins and monitored laying capacity, IgY concentration, and specific antibody titer over an extended period of 2 yr.