Impacts of Eimeria coinfection on growth performance, intestinal health and immune responses of broiler chickens.

Coccidiosis caused by Eimeria is one of the most severe chicken diseases and imposes huge economic losses to the poultry industry globally. Multi-Eimeria species coinfections are common with the most prevalent combination being mixtures of Eimeria acervulina and Eimeria tenella. Although detrimental impacts of either E. acervulina or E. tenella on chicken health are well recognized, no information is available regarding their coinfection effects so far. This study was designed to investigate the influence of coinfection with E. acervulina and E. tenella on broiler chickens. 144 one-day-old broiler chickens within each of trials (trial I or II) were divided into four groups, namely, control group (CG), E. acervulina infection group (EAIG), E. tenella infection group (ETIG) and dual (E. acervulina and E. tenella) infection group (DIG). Then, chickens were measured for weight loss, lesion scores, oocyst outputs, histological changes and expressions of pro-inflammatory (interleukin [IL]-6, IL-8 and IL-18), regulatory (IL-10 and IL-22) cytokines and Toll-like receptors (TLR; TLR2 and TLR4) as well as intestinal barrier (mucin 2 [MUC2] and fattey acid-bingding proteins 2 and 6 [FABP2 and FABP6])- and tight junction (TJ; zonula occluden-1 [ZO-1], occludin [OCLN], and claudins 1 and 5 [CLDN1 and CLDN5])-related proteins at 3, 5, 7, 10, 14 and 21 days post-infection, respectively. Our results consistently showed that although ETIG and DIG exhibited a higher level of weight loss and a more amount of oocyst excretion than EAIG, DIG had lighter lesions than EAIG in the early phase because of coinfection with E. tenella. A higher (P < 0.05) ratio of duodenal villous height to crypt depth was also observed in DIG than EAIG. Moreover, histological changes in the duodenum and cecum varied by single and dual Eimeria infections. Expressions of the intestinal barrier- and TJ-related genes of EAIG, ETIG and DIG were significantly (P < 0.05) upregulated but their levels exhibited differential changes among infected chickens. Similarly, the infected chickens showed significant (P < 0.05) inflammatory responses and higher (P < 0.05) expressions of TLRs in the intestines in comparison to CG. These results presented a comprehensive physiological, pathological and immunological characterization of E. acervulina and E. tenella coinfection in broiler chickens and also shed insights into pathogenesis of multi-coccidia coinfections.

Eimeria pragensis infection alters the gut microenvironment to favor extrinsic shiga toxin-producing Escherichia coli O157:H7 colonization in mice.

We examined the effects of Eimeria pragensis infection on intestinal peristalsis, goblet cell proliferation and intestinal flora in C57BL/6 mice. Intestinal peristalsis was evaluated by radiography using barium at 7 days post-infection (p.i.). The intestinal peristalsis of E. pragensis-infected mice was significantly suppressed compared with uninfected control mice. Twenty-three mice were divided into 5 groups of 4 or 5 mice each; 2 groups of mice were infected with E. pragensis and the others were kept uninfected. At 7 days p.i., E. pragensis-infected and -uninfected mice were sacrificed to examine goblet cell numbers in the intestines, and significant decreases were observed only in the infected mice. Shiga toxin-producing Escherichia coli (STEC) O157:H7 was inoculated orally in mice both infected and uninfected with E. pragensis at 7 days p.i., with the remaining mice used as uninoculated controls. When mice were sacrificed at 2 days after STEC inoculation, STEC was only detected in the intestines of E. pragensis-infected mice. Colonization of STEC was also confirmed by immunohistochemistry on the surface of epithelial cells in concurrently infected/inoculated mice. Also, an overgrowth of residential E. coli was observed only in E. pragensis-infected mice. These results suggest that E. pragensis induces the suppression of intestinal peristalsis and modifies the intestinal environment to facilitate artificially introduced STEC colonization and multiplication, in addition to residential E. coli overgrowth.

Reproductive injury in male BALB/c mice infected with Neospora caninum.

BACKGROUND: Neospora caninum is one of the main causes of abortion in pregnant animals. However, N. caninum-induced reproductive injury in male mice is still unclear. METHODS: Male BALB/c mice were infected with a bovine isolate of N. caninum, and the organ coefficients of the testis and epididymis were measured. Lesions in the testis and epididymis were observed by light microscopy and transmission electron microscopy. Expression of the spermatogenic cell apoptosis-related proteins p53 and caspase-3 was detected by western blot. The expression of spermatogenesis-related genes in the testis was detected by reverse transcription-PCR. Sperm morphology and motility were observed. The levels of nitric oxide (NO) and antisperm antibody (AsAb) in the testicular homogenates and hormones in the serum were detected by enzyme-linked immunosorbent assay. The reproductive capacity of the male mice was detected using a reproduction test. RESULTS: The organ coefficients of the testis and epididymis of the experimental group were significantly downregulated. Light microscopy examination revealed that the spermatogenic cells of the testis were arranged in a disordered manner, and the number was reduced. The number of sperm in the epididymal lumen was significantly reduced, and the cytoplasm exhibited vacuolation and degeneration. Ultrastructural studies revealed that the cells of the testis and epididymis tissues showed varying degrees of disease. The level of p53 and caspase-3 expression in the testis was significantly upregulated. The expression of the testicular spermatogenesis-related genes Herc4, Ipo11 and Mrto4 were strongly downregulated. Observation of sperm by microscopic examination revealed significantly reduced sperm density and sperm motility, and the number of sperm deformities was significantly increased. The level of NO and AsAb was significantly increased. The levels of luteinizing hormone, follicle-stimulating hormone and gonadotropin-releasing hormone were significantly upregulated, whereas the levels of testosterone, thyrotropin-releasing hormone, thyroxine and thyroid-stimulating hormone were significantly downregulated. After challenge, the infected male mice and healthy female mice were caged together: the subsequent fetal death rate was increased, and the conception rate, litter size, number of live births and the birth weight were significantly reduced. CONCLUSIONS: Infection of male BALB/c mice with the bovine isolate of N. caninum induced varying degrees of injury to the testis, epididymis and sperm of the mice, destroyed spermatogenesis and affected the reproductive capacity.

Ovine Abortion by Neospora caninum: First Case Reported in Argentina.

PURPOSE: The aim of this study was to describe for the first time a natural case of ovine abortion associated with Neospora caninum in a flock with reproductive losses in Argentina. MATERIALS AND METHODS: The analyzed flock consisted of 256 Texel sheep, of which 134 had been mated. A single blood sample was obtained by jugular vein puncture from 220 ewes (116 adult ewes, 104 yearling ewes) and 93 lambs. Serum samples and fetal fluid were tested using the indirect fluorescence antibody test to detect antibodies against N. caninum and T. gondii. Fetal and placental tissues from aborted fetus were examined by standard gross pathology procedures and were tested using histopathology and immunohistochemistry. Moreover, DNA from fetal and placental tissues was isolated and a PCR assay to detect N. caninum, T. gondii and Chlamydia spp. was used. RESULTS AND DISCUSSION: The pregnancy rate was 89% (119/134), the abortion rate was 8.4% (10/119) whereas the perinatal mortality rate was 15% (16/109). Out of 116 adult ewes sampled, 34.48% presented anti-N. caninum antibodies. Ten ewes had aborted, and one fetus was directly submitted to the diagnostic laboratory for further processing. Antibodies against N. caninum were detected in fetal fluid and in the aborted dam. Histopathological analysis in fetal tissues showed multifocal lymphohistiocytic glossitis, diffuse mild lymphohistiocytic endocarditis, pericarditis and focally extensive myocarditis. Severe multifocal necrotizing placentitis and diffuse mild lymphohistiocytic placentitis with the presence of lymphohistiocytic vasculitis were observed in placenta. N. caninum was immunolabeled in the placenta and fetal tongue. In addition, N. caninum DNA was detected in placenta, central neural system, lung and heart of the aborted fetus. There was no evidence of other infectious abortifacients in the aborted fetus. CONCLUSION: The present study described for the first time an ovine abortion caused by N. caninum in Argentina. Further investigations at a larger scale are required to establish the role of N. caninum as an important cause of reproductive losses in sheep flocks from the region.

Analysis of gut microbiota and the effect of lauric acid against necrotic enteritis in Clostridium perfringens and Eimeria side-by-side challenge model.

Gut microbiota has been demonstrated to be involved in intestinal nutrition, defense, and immunity, as well as participating in disease progression. This study was to investigate gut microbiota changes in chickens challenged with netB-positive Clostridium perfringens strain (CP1) and/or the predisposing Eimeria species (Eimeria) and fed diets with fishmeal supplementation. In addition, the effects of lauric acid, a medium-chain fatty acid (MCFA), on necrotic enteritis (NE) reduction and modulation of microbiota were evaluated. The results demonstrated that microbial communities in the jejunum were distinct from those in the cecum, and the microbial community change was more significant in jejunum. Challenge of CP1 in conjunction with Eimeria significantly reduced species diversity in jejunal microbiota, but cecal microbiota remained stable. In the jejunum, CP1 challenge increased the abundance of the genera of Clostridium sensu stricto 1, Escherichia Shigella, and Weissella, but significantly decreased the population of Lactobacillus. Eimeria infection on its own was unable to promote NE, demonstrating decrements of Clostridium sensu stricto 1 and Lactobacillus. Co-infection with CP1 and Eimeria reproduced the majority of NE lesions with significant increment of Clostridium sensu stricto 1 and reduction in Lactobacillus. The advance of changes on these two taxa increased the severity of NE lesions. Further analyses of metagenomeSeq, STAMP, and LEfSe consistently showed significant overgrowth of Clostridium sensu stricto 1 was associated with NE. The supplementation of lauric acid did not reduce NE incidence and severity but decreased the relative abundance of Escherichia Shigella. In conclusion, significant overgrowth of C. perfringens as well as other Clostridium species in Clostridium sensu stricto 1 with the decrement of Lactobacillus in the jejunum is the featured microbiota correlated with NE. Controlling proliferation of Clostridium sensu stricto 1 and manipulation of Lactobacillus in the jejunum should be the strategy to prevent NE.

Evaluation of abortions spontaneously induced by Neospora caninum and risk factors in dairy cattle from Lima, Peru.

Our objective was to identify the direct and indirect presence of Neospora caninum in dairy cattle and their aborted fetuses from Lima, Peru. A total 219 blood samples obtained from dairy cattle with records of spontaneous abortion were collected to detect antibodies against N. caninum in serum with indirect ELISA and search for risk-factor associations. 68 fetal aborted tissue samples of these cows were analyzed by PCR, indirect ELISA and histopathology assay to detect N. caninum presence. The prevalence ratio (PR) and 95% confidence intervals (CI) were estimated. Univariate analysis was performed using the chi-squared test. Among the 68 aborted fetuses collected, 10 (15%) were positive in at least two diagnostic tests. Among 219 serum samples, 46.6% (95% CI: 40.0%-53.3%) were positive. Cows with 4 years or older (PR: 7.10; 95% CI: 4.89-10.67) and multiparous (PR: 1.76; 95% CI: 1.11-2.80) were found to be more likely to possess N. caninum antibodies. This study detects presence of N. caninum in dairy cattle and their aborted fetus from Lima valley, suggesting biosecurity management improve to neosporosis control.

Coxiella burnetii associated with BVDV (Bovine Viral Diarrhea Virus), BoHV (Bovine Herpesvirus), Leptospira spp., Neospora caninum, Toxoplasma gondii and Trypanosoma vivax in reproductive disorders in cattle.

This is a cross-sectional study to assess the presence of antibodies in ruminants against selected pathogens associated with reproductive disorders in cattle in four Brazilian states, including the zoonotic agent Coxiella burnetii. The used tests were Virus Neutralization Assay for IBR and BVD, Microscopic Agglutination Test for Leptospira spp., Indirect Fluorescent Antibody Test (IFAT) for C. burnetii and Toxoplasma gondii, and Enzyme-Linked Immunosorbent Assay for Neospora caninum and Trypanosoma vivax. Seropositivity for C. burnetii was 13.7% with titers from 128 to 131,072; 57.8% for BoHV-1, with titers between 2 and 1,024; 47.1% for BVDV-1a, with titers from 10 to 5,120; 89.2% for N. caninum; 50% for T. vivax; and 52.0% for Leptospira spp., with titers between 100 to 800 (the following serovars were found: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona and Icterohaemorrhagiae); 19.6% for T. gondii with titer of 40. This is the first study that has identified C. burnetii in cattle associated with BoHV and BVDV, N. caninum, Leptospira spp., T. gondii and T. vivax. Thus, future studies should be conducted to investigate how widespread this pathogen is in Brazilian cattle herds.

Coxiella burnetii associated with BVDV (Bovine Viral Diarrhea Virus), BoHV (Bovine Herpesvirus), Leptospira spp, Neospora caninum, Toxoplasma gondii and Trypanosoma vivax in reproductive disorders in cattle / Coxiella burnetii associada ao BVDV (Vírus da Diarreia Viral Bovina), BoHV (Vírus do Herpes Bovino), Leptospira spp, Neospora caninum, Toxoplasma gondii e Trypanosoma vivax em distúrbios reprodutivos em bovinos

Abstract This is a cross-sectional study to assess the presence of antibodies in ruminants against selected pathogens associated with reproductive disorders in cattle in four Brazilian states, including the zoonotic agent Coxiella burnetii. The used tests were Virus Neutralization Assay for IBR and BVD, Microscopic Agglutination Test for Leptospira spp., Indirect Fluorescent Antibody Test (IFAT) for C. burnetii and Toxoplasma gondii, and Enzyme-Linked Immunosorbent Assay for Neospora caninum and Trypanosoma vivax. Seropositivity for C. burnetii was 13.7% with titers from 128 to 131,072; 57.8% for BoHV-1, with titers between 2 and 1,024; 47.1% for BVDV-1a, with titers from 10 to 5,120; 89.2% for N. caninum; 50% for T. vivax; and 52.0% for Leptospira spp., with titers between 100 to 800 (the following serovars were found: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona and Icterohaemorrhagiae); 19.6% for T. gondii with titer of 40. This is the first study that has identified C. burnetii in cattle associated with BoHV and BVDV, N. caninum, Leptospira spp., T. gondii and T. vivax. Thus, future studies should be conducted to investigate how widespread this pathogen is in Brazilian cattle herds.

Resumo Este é um estudo transversal para avaliar a presença de anticorpos em ruminantes contra patógenos selecionados e associados a distúrbios reprodutivos em bovinos de quatro estados brasileiros, incluindo o agente zoonótico Coxiella burnetii. Os testes utilizados foram Teste de Vírus-Neutralização para BoHV e BVDV, teste de Aglutinação Microscópica para Leptospira spp., Reação de Imunofluorescência Indireta for C. burnetii e Toxoplasma gondii, e Ensaio de Imunoabsorção Enzimática para Neospora caninum e Trypanosoma vivax. A soropositividade para C. burnetii foi de 13,7% com títulos de 128 a 131.072; 57,8% para BoHV-1, com títulos entre 2 a 1.024; 47,1% para BVDV-1a, com títulos de 10 a 5.120; 89,2% para N. caninum; 50% para T. vivax; e 52,0% para Leptospira spp., com títulos entre 100 a 800 (sorovares encontrados: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona e Icterohaemorrhagiae) 19,6% para T. gondii com título de 40. Este é o primeiro estudo que evidencia a participação de C. burnetii em bovinos associada ao Vírus da Rinotraqueíte bovina infecciosa e da diarreia viral bovina, N. caninum, Leptospira spp., T. gondii e T. vivax em bovinos. Desta forma, futuros estudos devem ser conduzidos a fim de investigar o quão disseminado se encontra este patógeno em rebanhos bovinos brasileiros.

Evaluation of abortions spontaneously induced by Neospora caninum and risk factors in dairy cattle from Lima, Peru / Avaliação de abortos induzidos espontaneamente por Neospora caninum e fatores de risco em bovinos leiteiros de Lima, Peru

Abstract Our objective was to identify the direct and indirect presence of Neospora caninum in dairy cattle and their aborted fetuses from Lima, Peru. A total 219 blood samples obtained from dairy cattle with records of spontaneous abortion were collected to detect antibodies against N. caninum in serum with indirect ELISA and search for risk-factor associations. 68 fetal aborted tissue samples of these cows were analyzed by PCR, indirect ELISA and histopathology assay to detect N. caninum presence. The prevalence ratio (PR) and 95% confidence intervals (CI) were estimated. Univariate analysis was performed using the chi-squared test. Among the 68 aborted fetuses collected, 10 (15%) were positive in at least two diagnostic tests. Among 219 serum samples, 46.6% (95% CI: 40.0%-53.3%) were positive. Cows with 4 years or older (PR: 7.10; 95% CI: 4.89-10.67) and multiparous (PR: 1.76; 95% CI: 1.11-2.80) were found to be more likely to possess N. caninum antibodies. This study detects presence of N. caninum in dairy cattle and their aborted fetus from Lima valley, suggesting biosecurity management improve to neosporosis control.

Resumo O objetivo do trabalho foi diagnosticar a presença direta e indireta de Neospora caninum em fetos abortados e de soros de bovinos leiteiros de Lima, Peru. Um total de 219 amostras de sangue obtido de vacas leiteiras, com registros de abortos espontâneos, foi coletado para detectar anticorpos contra N. caninum no soro (pelo ELISA indireto), e para estudar associações com fatores de risco. Foram examinadas 68 amostras de tecido fetal abortado das vacas soropositivas pela PCR, ELISA indireto e histopatologia para determinar a presença de N. caninum. A taxa de prevalência (PR) e o intervalo de confiança (CI) de 95% foram estimados. Análise univariada foi realizada usando o teste de Qui-quadrado. Entre os 68 fetos abortados, 10 (15%) foram positivos em pelo menos dois testes diagnósticos. Entre as 219 amostras de soro, 46,6% (95% IC: 40,0%-53,3%) foram positivas. Vacas com 4 anos ou mais de idade (RP: 7,10; 95% IC: 4,89-10,67) e multíparas (RP: 1,76; 95% IC: 1,11-2,80) apresentaram maior frequência de anticorpos contra N. caninum. Este estudo demonstrou a presença de N. caninum em bovinos leiteiros e em fetos abortados oriundos do vale de Lima, sugerindo a implementação de medidas de biossegurança, para o controle da neosporose.

Heat stress reduces Eimeria spp. infection and interferes with C. perfringens infection via activation of the hypothalamic-pituitary-adrenal axis.

Heat stress has a relevant effect on animal health and productivity. Stress and environmental changes can contribute to disease development, such as avian necrotic enteritis (NE). The goal of this study was to analyze the effects of heat stress applied to broiler chickens in an experimental model of co-infection with Clostridium perfringens and Eimeria spp. Therefore, the current study was designed to analyze the effect of heat stress to broiler chickens in an experimental model of infection or co-infection with Clostridium perfringens and Eimeria spp. C. perfringens was given in the poultry feed and the Eimeria infection was induced by gavage with a live oocysts vaccine dose 30 times higher than the manufacturer recommendation. We observed a reduction in the secretory IgA concentration in the jejunum and ileum in heat-stressed chickens compared to non-stressed chickens. Decreased maximum scores of intestinal necrosis, crypt abscesses and transmural lesions were observed in the heat-stressed chickens co-infected and infected with Eimeria compared to the respective unstressed groups. Heat stress caused an increase the intestinal lesion scores in chickens infected with C. perfringens only. The crypt depth was greater in chickens from the heat-stressed groups compared to the non-stressed groups. We also demonstrated that HS decreased infection and/or Eimeria development in the intestinal epithelium, reducing the harmful potential of C. perfringens.

Impact of Eimeria tenella Coinfection on Campylobacter jejuni Colonization of the Chicken.

Eimeria tenella can cause the disease coccidiosis in chickens. The direct and often detrimental impact of this parasite on chicken health, welfare, and productivity is well recognized; however, less is known about the secondary effects that infection may have on other gut pathogens. Campylobacter jejuni is the leading cause of human bacterial foodborne disease in many countries and has been demonstrated to exert negative effects on poultry welfare and production in some broiler lines. Previous studies have shown that concurrent Eimeria infection can influence the colonization and replication of bacteria, such as Clostridium perfringens and Salmonella enterica serovar Typhimurium. Through a series of in vivo coinfection experiments, this study evaluated the impact that E. tenella infection had on C. jejuni colonization of chickens, including the influence of variations in parasite dose and sampling time after bacterial challenge. Coinfection with E. tenella resulted in a significant increase in C. jejuni colonization in the cecum in a parasite dose-dependent manner but a significant decrease in C. jejuni colonization in the spleen and liver of chickens. The results were reproducible at 3 and 10 days after bacterial infection. This work highlights that E. tenella not only has a direct impact on the health and well-being of chickens but can have secondary effects on important zoonotic pathogens.

Protozoal coinfection in horses with equine protozoal myeloencephalitis in the eastern United States.

BACKGROUND: Infection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis. HYPOTHESIS/OBJECTIVES: To assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii. We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites. ANIMALS: One hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM. METHODS: Case review. Archived serum and cerebrospinal fluid (CSF) from 101 horses were examined. Inclusion criteria included neurologic disease, antemortem or postmortem diagnosis of EPM or CVSM, and availability of serological results or archived samples for testing. Additional testing for antibodies was performed on serum for T. gondii, as well as serum and CSF for N. hughesi. RESULTS: Horses with EPM were more likely than horses with CVSM to have positive immunologic results for S. neurona on serum (95.9% versus 76.9%, P = .0058), CSF (98.0% versus 44.2%, P < .00001), and serum : CSF titer ratio (91.8% versus 0%, P < .00001). Positive results for Neospora and Toxoplasma were uncommon, with total seroprevalence rates of 12.9% and 14.9%, respectively. The proportions of EPM cases testing positive for Neospora and Toxoplasma (16% and 12%) were not different from the proportions of CVSM cases testing positive (10% and 17%, P = .31 and .47, respectively). CONCLUSION: Results do not indicate an important role for protozoal coinfection in EPM in the eastern United States.

Neospora caninum and Ehrlichia canis co-infection in a dog with meningoencephalitis.

An 8-year-old mixed-breed dog was presented for acute, progressive weakness and ataxia, inappetence, and weight loss. The patient was mentally normal, but nonambulatory, with a right head tilt, right positional ventral strabismus, and slight head tremors. A neurologic lesion was localized to the cerebellum and right brainstem. Cerebrospinal fluid (CSF) analysis showed a markedly increased protein concentration and mixed pleocytosis, with eosinophil predominance (44%), intracytoplasmic inclusions within eosinophils, consistent with Ehrlichia canis (E canis) morulae, and Toxoplasma gondii (T gondii) or Neospora caninum (N caninum) tachyzoites within eosinophils and monocytes. A serum indirect immunofluorescent antibody test was positive for N caninum (titer 1:12 800) and negative for T gondii. Both blood and CSF PCR results were N caninum- and E canis-positive and T gondii- and Anaplasma phagocytophilum-negative, and blood PCR, but not CSF PCR, was Hepatozoon canis-positive. The dog was treated for 30 days with clindamycin, sulfamethoxazole-trimethoprim, doxycycline, prednisone, and cephalosporin, but did not improve neurologically, and was euthanized. Brain histopathology showed moderate multifocal, subacute meningoencephalitis with necrosis and gliosis. The neurologic disease was mostly attributed to central nervous system (CNS) neosporosis, with the possible contribution of ehrlichiosis, which was likely a manifestation of blood-brain barrier disruption. Hepatozoonosis was probably a result or cause of underlying immunosuppression. To our knowledge, this is the first report of CNSN caninum and E canis co-infection detected by both CSF PCR and cytology and E canis morulae identified within CSF eosinophils.

A clinical case of neosporosis in a 4-week-old holstein friesian calf which developed hindlimb paresis postnatally.

A 4-week-old female Holstein Friesian calf presented with hindlimb paresis. Neurologic examination of spinal reflexes revealed depressed or absent reflexes of the hindlimbs. Menace responses on both sides disappeared on examination of cranial nerves. The calf was finally diagnosed with Neospora caninum infection by pathological findings including nonsuppurative inflammation associated with cysts in the cerebrum and spinal cord. High levels of antibody against recombinant surface antigen 1 of N. caninum (NcSAG1) were detected by ELISA from both serum and cerebrospinal fluid (CSF) samples. This result suggests that detection of antibodies against N. caninum by NcSAG1-ELISA in serum and CSF could be useful for the clinical diagnosis of neosporosis in calves with acquired neurological signs.

Serratospiculosis in Captive Peregrine Falcons (Falco peregrinus) in Switzerland.

Infection with Serratospiculum species was identified in a captive peregrine falcon (Falco peregrinus) in Switzerland. Pathologic and parasitologic examination results revealed generalized severe granulomatous airsacculitis, with intralesional adults, larvae, and eggs of Serratospiculum species. Subsequently, an individual coprological analysis of the remaining 15 falcons (peregrine falcons and gyrfalcons [Falco rusticolus]) from the same owner was performed. Eggs of Serratospiculum species (4 birds) and Capillaria species (11 birds), and oocysts of Caryospora species (1 bird) were detected. Treatment with ivermection (2 mg/kg SC) was effective, as none of the falcons excreted Serratospiculum species eggs 10 days after one dose. To our knowledge, this is the first report of infection with Serratospiculum species in captive falcons in Europe.

Relationships between certain metabolic diseases and selected serum biochemical parameters in seropositive dairy cows against Neospora caninum infection in different stages of lactation

Neospora caninum is an important cause of abortion in dairy cattle. The general health of affected cows has not been investigated before. Therefore, the main objective of this study was to identify possible relationships between certain metabolic diseases and selected serum biochemical parameters in seropositive dairy cows against N. caninum antibodies in different stages of lactation. The study was carried out using 72 N. caninum seropositive cows and 61 seronegative dairy cows (control). Serum from all cows was tested to determine their N. caninum status (seropositive vs seronegative) using commercially available indirect enzyme-linked immunosorbent assay test kit (iELISA). In addition, serum biochemical parameters including beta-hydroxybutyrate (BHB), glucose, creatinine, blood urea nitrogen, total protein, albumin, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH) and gamma-glutamyltranspeptidase (GGT) were determined using routine laboratory methods. The stage of lactation was obtained at the time of sampling from farm records. Student independent t-test showed that there was a significant difference in the serum concentrations of BHB, AST, ALT, and LDH between seropositive and seronegative cows. There was no significant association between seropositivity and the stage of lactation. However, multivariable logistic regression analysis showed that there was a strong association between seropositivity and BHB concentrations. Results of this study indicate a possible relationship between N. caninum seropositivity and certain metabolic diseases such as ketosis and fatty liver syndrome in dairy cows.

Risk factors for Neospora caninum infection in dairy cattle and their possible cause-effect relation for disease.

Neospora caninum causes reproductive problems in cattle such as abortion, premature birth, retention of fetal membranes, and metritis. Therefore, this study aimed to verify possible risk factors for N. caninum infection in dairy cattle and their cause-effect relation to neosporosis. Serum samples of 1518 dairy cows from the West of Santa Catarina State, Southern Brazil were analyzed by indirect immunofluorescence assay (IFA) for N. caninum, where 466 were found to be positives (30.69%-CI95%; 28.3-33.0). In addition, an epidemiological survey was conducted in order to verify possible risk factors for neosporosis and their relation to the disease. The presence of dogs in the farm was strongly associated with IFA positive results for N. caninum, and lack of history for neosporosis in the farm increased the chances of positivity in 66%. It was found a significant cause-effect relation between the occurrence of reproductive problems and the presence of antibodies against N. caninum (p = 0.05). It is possible to conclude that N. caninum is widely distributed in dairy farms of the Western part of Santa Catarina state, Brazil, and that the occurrence of reproductive problems is directly related to the disease with the presence of dogs as a risk factor for N. caninum infection.

Can hierarchical modeling improve our understanding of bovine abortion due to Neospora caninum infection?

The purpose of this study was to use mixed logistic regression to evaluate the association between Neospora caninum serostatus and abortion, accounting for the effects of farms. The main objective was to explore the interpretation of this model and discuss the contribution of this analysis to our understanding of the disease's epidemiology. A mixed-effects logistic model using farms as a random effect and the serostatus for N. caninum, age of cattle and farm location as fixed effects was performed. The data from 1256 cows over 15 months of age from 60 farms were used, and the abortion information was obtained from farm records. A significant association between N. caninum serostatus and abortion was found (p<0.0001). Seropositive cows had 6.63 times greater odds of having a history of previous abortion (95% CI: 4.35-13.37). There was remarkable variability across farms in the probability of a cow having a history of an abortion. Including the effects of the farms in the regression, it was possible to estimate an intraclass correlation coefficient (ICC) of 16%. That means that 16% of the variation in abortion occurrence that was not explained by the fixed effects was due to farms. In practical terms, this variation means that while there are farms with several seropositive cows and no/few abortion cases, the opposite is also true, with a high number of abortions in farms with low/medium seroprevalence. The remaining variability (84%) was not explained by the effect of N. caninum, age, region, and the effect of farms, i.e., it is due to unknown factors that are causing abortions. The results of this study reinforce the importance of N. caninum as a cause of abortions and demonstrate the significant heterogeneity in the probability of a cow having a history of an abortion that cannot be explained completely by N. caninum serostatus, age or location. Including the hierarchical structure of the population along with correct interpretation of the model estimates helps us understand the effect of the farms, i.e., the probability of a cow abortion conditional to the farms, which also contributes to our understanding of the epidemiology of abortions caused by neosporosis. The use of hierarchical models and reporting the ICC should be encouraged.

Liver mitochondrial oxygen consumption and proton leak kinetics in broilers supplemented with dietary copper or zinc following coccidiosis challenge.

Mitochondrial respiration was assessed in sixteen 7-day-old broilers as a subset of a larger study assessing the effects of Cu and Zn supplementation above requirements with a coccidiosis challenge on gain/feed ratio. The birds were selected from four treatments (four birds/treatment): a control diet (Cu 15 mg/kg and Zn 60 mg/kg) + coccidiosis challenge (CC), a Cu diet with 245 mg/kg Cu from tribasic copper chloride (TBCC) + CC, a negative control diet (Cu 15 mg/kg and Zn 60 mg/kg) - CC and a Zn diet with 2000 mg/kg Zn from ZnO. The diets were composed of 49% corn, 40% soybean meal, 6.2% vegetable oil (diet dry matter = 90.62%, crude protein = 21.37%, fat = 7.7%, metabolizable energy = 12.1 MJ/day) and were fed for 14 days. Birds were dissected, and approximately one gram of liver tissue was used for mitochondrial oxygen consumption and proton leak kinetics assays. Respiratory control ratio and mitochondrial proton leak assessed by calculating rates of oxygen consumption at 175mV membrane potential were greater for the negative control group, but there were no differences in average gain/feed among treatments. In summary, broilers that did not undergo coccidiosis challenge had lower proton leak and higher respiratory control ratio. However, the impact of supplementation of Cu and Zn above requirements did not appear to prevent changes in respiratory control ratio and proton leak kinetics with coccidiosis challenge.

Foetal death in naive heifers inoculated with Neospora caninum isolate Nc-Spain7 at 110 days of pregnancy.

Neospora caninum infection is a leading cause of abortion in cattle worldwide. The pathogenesis of bovine neosporosis, particularly during the second term of gestation when most abortions occur in naturally infected dams, is poorly understood. In the present study foetal death was observed in 3 of 6 experimentally infected dams at 110 days of gestation after 6 weeks of experimental period. All experimental heifers were febrile between 3 and 5 days post infection (dpi). Inoculated dams seroconverted by 3-4 weeks post-infection with higher mean antibody titres in aborting dams compared to non-aborting heifers, although not significantly (p > 0.05). Neospora caninum DNA was detected in all infected foetuses and placentas, and three infected foetuses also had N. caninum antibodies. The parasite burden was higher in the brain of dead/aborted foetuses than in live foetuses. Interestingly, high IFN-γ production was detected in foetal fluids of a dead foetus found upon euthanasia of its dam, while no IFN-γ was observed in amniotic, allantoic and/or foetal fluids in the three infected foetuses that were alive upon maternal euthanasia. The present study confirms that the infection of dams on gestation day 110 with 10(7) tachyzoites of the Nc-Spain7 isolate causes abortion. The fact that some infected dams aborted and some did not is relevant to the understanding of N. caninum pathogenesis of abortion in naturally infected cows.