Impact of colibacillosis on production in laying hens associated with interference of the phosphotransfer network and oxidative stress.

The objective of this study was to evaluate the productive impact of colibacillosis on laying hens and to investigate whether energetic metabolism and oxidative stress were involved in the pathogenesis of the disease. An experimental shed containing 270 laying hens of the Hy-Line lineage (32 weeks old) presented approximately 40% daily laying, and many birds presented with diarrhea and apathy followed by death. Necropsy revealed macroscopic lesions compatible with colibacillosis and infectious agent Escherichia coli was isolated from fecal samples of all birds in the infected group, as well as from tissue (ovary, liver and peritoneum). Sixteen chickens were selected for this study, divided into two groups: Control (animals without clinical alterations) and infected (with diarrhea and apathetic). E. coli isolates were subjected to the antimicrobial susceptibility testing according to the methodology approved by CLSI, 2018. This testing showed sensitivity to gentamicin, amoxicillin, norfloxacin and colistin. It was then determined that laying hens would be treated with norfloxacin (15 mg/kg) diluted in water offered at will to the birds for three days. Blood collections were performed via brachial vein after the diagnosis of E. coli (before starting treatment) and seven days after treatment. Three debilitated chickens died on the second day after initiating therapy. Before treatment, birds with clinical signs had higher levels of lipoperoxidation (LPO) and activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) than in the control group (asymptomatic animals). After treatment, LPO levels remained higher in birds that had clinical disease (infected group), whereas the activity of SOD and GPx enzymes did not differ between groups. Activity levels of creatine kinase (CK) and pyruvate kinase (PK) were higher in the group of chickens with clinical disease before treatment. Post-treatment, no differences were observed between groups in terms of CK; however, PK activity remained high in these animals. In the hens that died, there were lesions characteristic of avian colibacillosis, with ovary involvement, explaining the low laying activity of the birds at their peak of production. For 10 days after starting treatment, the percentage of laying increased to 90%. Therefore, we conclude that colibacillosis interferes with the phosphotransfer network by stimulating ATP production, in addition to causing oxidative stress of the birds during laying, that negatively affects health and productive efficiency.

Escherichia coli used as a biomarker of antimicrobial resistance in pig farms of Southern Brazil.

The objective of this study was to verify the presence of antimicrobial resistant strains of Escherichia coli in pig farms and to use it as a biomarker to evaluate phenotypic and genotypic profiles of antimicrobial susceptibility, as well as the presence of Extended Spectrum Beta-lactamases (ESBLs) and fluoroquinolone resistance genes. Several samples (n = 306) collected from swine farms (n = 100) of Southern Brazil were used for E. coli isolation: 103 of swine feces, 105 of water, and 98 of soil. E. coli isolates were submitted to the disk-diffusion test to verify their antimicrobial susceptibility, to disk-approximation test to detect ESBL-producers, and to PCR analysis to search for ESBLs genes (blaCTY-M2, blaSHV-1, blaTEM-1, blaCTX-M2, blaOXA-1, blaPSE-1) and quinolone resistance genes (qnrA, qnrB and qnrS). The percentage of E. coli isolates found in feces, water and soil samples was 66.02%, 30.48% and 35.71%, respectively. The highest percentages of resistance were obtained for sulfamethoxazole associated with trimethoprim (63.70%), colistin (45.19%) and enrofloxacin (39.26%). Regarding the levels of multidrug resistance, 37.04% of the isolates were resistant to three or more classes of antimicrobials. The most common profile (16%) of multirresistance was GEM-SUT-ENO-COL. The index of multiple resistance to antimicrobials (IRMA) was above 0.2 in 78% of the multiresistant isolates. Out of 135 E. coli isolates, 7.41% was ESBL-producers, of which 50% showed the blaCMY-M2 gene, 40% the blaTEM-1 and 70% the qnrS gene. Of non-ESBL-producing strains resistant to enrofloxacin, 13.04% were positives for qnrS gene. These results demonstrated the presence of fecal contamination in the environment, in addition to high resistance indexes for several antimicrobials, including beta-lactams and fluoroquinolones, which was confirmed by the genetic detection of ESBLs and qnr genes.

Ecto-enzymes activities in splenic lymphocytes of mice experimentally infected by Trypanosoma cruzi and treated with specific avian immunoglobulins: an attempt to improve the immune response.

The aim of this study was to evaluate the therapeutic efficacy of specific avian polyclonal antibodies (IgY) against Trypanosoma cruzi and their interaction with ecto-enzymes of the purinergic system (NTPDase and adenosine deaminase (ADA) activities) in splenic lymphocytes. For this, mice were divided into six groups: three non-infected (A, B, and C) and three infected (D, E, and F). The groups A and D were composed by negative and positive controls, respectively; while the groups B and E were treated prophylactically with IgY (50 mg/kg), and the groups C and F were treated therapeutically with IgY (50 mg/kg). Treatment with IgY reduced parasitemia on day 6 post-infection (PI) compared to the infected control group, but it was similar on day 8 PI. Moreover, infected and treated animals (the groups E and F) did not show neither amastigotes in the cardiac tissue nor cardiac lesions when compared to the positive control group (the group D). The E-NTPDase (ATP and ADP as substrate) and ADA activities in splenic lymphocytes increased significantly in the positive control group (the group D) compared to the negative control group (the group A). The therapeutic treatment of IgY (the group F) was able to prevent the increase of E-NTPDase and E-ADA activities compared to the positive control group (the group D), but this finding was not observed in animals that received the prophylactic treatment (the group E). The therapeutic treatment of IgY may be considered an interesting approach to improve the immune response of mice experimentally infected by T. cruzi.

Gastrointestinal protozoa in dairy calves: identification of risk factors for infection / Protozoos gastrointestinales en terneros lecheros: identificación de factores de riesgo para la infección

ABSTRACT Objective. This study aimed to evaluate the occurrence of gastrointestinal protozoa in dairy calves and to identify potential risk factors for this type of infection. Materials and methods. For this purpose, 243 fecal samples were collected from calves up to 60 days of age in 43 dairy farms located in the West region of Santa Catarina state, Brazil. Samples were examined by centrifugal-flotation technique. Results. As a result, Giardia was present in 26.75% (65/243) of all samples, Eimeria in 21.81% (53/243), and Cryptosporidium in 20.99% (51/243). Additionally, 46.50% (113/243) of the samples were negative for any protozoa, while 39.10% (95/243) and 14.40% (35/208) showed single and mixed infections, respectively. There was a higher association between Cryptosporidium and Giardia (6.99%) in cases of mixed infections. However, the triple protozoa association had the lowest prevalence in mixed infections (2.06%). Epidemiologically, a questionnaire was applied to determine risk factors for these parasitic infections. Based on the statistical model applied, some risk factors for Cryptosporidium infections were identified, highlighting feeding management, period of time that calves stayed with their mothers (cows), and contact with dogs; the risk of contracting Giardia increased according to the milk source, while the floor type bedding, and age were appointed as risks factors for Eimeria. Conclusions. Therefore, it is possible to confirm that Giardia, Cryptosporidium and Eimeria may infect dairy calves, and the knowledge of some risk factors associated to their infection in calves.

RESUMEN Objetivo. El objetivo evaluar la ocurrencia de protozoos gastrointestinales en terneros lecheros y de identificar posibles factores de riesgo para infección. Materiales y métodos. Se recogieron 243 muestras de heces de terneros de hasta 60 días de edad en 43 granjas lecheras ubicadas en la región del oeste del estado de Santa Catarina, Brasil. Las muestras fueron examinadas por la técnica de centrifugación-flotación. Resultados. Como resultado, Giardia estaba presente en 26.75% (65/243) de todas las muestras, Eimeria en 21.81% (53/243), y Cryptosporidium en 20.99% (51/243). Además, 46.50% (113/243) de las muestras fueron negativas para cualquier protozoos, mientras que 39.10% (95/243) y 14.40% (35/208) mostraron infecciones simples y mixtas, respectivamente. Hubo una mayor asociación entre Cryptosporidium y Giardia (6.99%) en los casos de infecciones mixtas. Sin embargo, la asociación de triple protozoos tenía la menor prevalencia de infecciones mixtas (2.06%). Epidemiológicamente, se aplicó un cuestionario para determinar los factores de riesgo para estas infecciones parasitarias. Se han identificado algunos factores de riesgo de infecciones por Cryptosporidium, destacando manejo de la alimentación, periodo de tiempo que los terneros permanecieron con sus madres (vacas), y el contacto con los perros; el riesgo de contraer Giardia incrementado en función de la fuente de la leche, mientras que el tipo de suelo de las camas, y la edad fueron nombrados como los riesgos de factores de Eimeria. Conclusiones. Es posible confirmar que Giardia, Cryptosporidium y Eimeria pueden infectar a terneros lecheros, y el conocimiento de algunos factores de riesgo asociados a la infección en terneros.

Avian antibodies (IgY) against Trypanosoma cruzi: Purification and characterization studies.

Trypanosoma cruzi is a flagellated protozoan belonging to the Trypanosomatidae family, the etiologic agent of Chagas disease. Currently, there is neither a licensed vaccine nor effective treatment, characterizing an unmet clinical need. The IgY refers to the egg yolk immunoglobulin (Y=yolk) and its production and use are subjects of many studies due to the diversity of its diagnostic and therapeutic applications. Several researchers have shown that the use of specific IgY may prevent and/or control infectious and parasitic diseases. Based on these evidences, the aim of this study was to immunize chickens with trypomastigotes of T. cruzi in order to produce highly effective and pure antibodies (IgY), as well as extract, characterize, quantify, and verify cytotoxic effects of IgY anti-T. cruzi. After the induction of IgY production by chickens, the eggs were collected and the IgY was extracted by method of precipitation of polyethylene glycol 6000. The IgY anti-T. cruzi characterization was performed using polyacrylamide gel electrophoresis (SDS-PAGE), western-blot and enzyme-linked immunosorbent assay (ELISA). Moreover, the cytotoxic or proliferative effects of IgY anti-T. cruzi was verified by MTT assay. The concentration of IgY in yolk was 8.41±1.47mg/mL. The characterization of IgY reveled bands of stained peptides with molecular weight between 75 and 50kDa and 37 and 25kDa. In the ELISA test was observed that there was antigen-antibody reaction throughout the sample period. The concentrations of 1, 5 and 10mg/mL of IgY anti-T. cruzi presented no cytotoxic of proliferative effects in mononuclear and VERO cells in vitro. The results indicated that T. cruzi is able to generate a high production of specific immunoglobulins in chickens, it did not cause damage to the cell membrane and no proliferative effect.

Salmonella Heidelberg: Genetic profile of its antimicrobial resistance related to extended spectrum ß-lactamases (ESBLs).

The objective of this study was to evaluate the phenotypic and genotypic profile of antimicrobial susceptibility and the possible involvement of extended spectrum beta-lactamases (ESBLs) in the resistance profile of Salmonella Heidelberg (SH) isolated from chicken meat. We used 18 SH isolates from chicken meat produced in 2013 in the state of Paraná, Southern Brazil. The isolates were submitted to disk-diffusion tests and from these results it was possible to determine the number of isolates considered multiresistant and the index of multiple antimicrobial resistance (IRMA) against ten antimicrobials routinely used in human and veterinary medicine. It was considered multidrug resistant the isolate that showed resistance to three or more classes of antibiotics. Another test performed was the disc-approximation in order to investigate interposed zones of inhibition, indicative of ESBLs production. In the isolates that presented multidrug resistance (18/18), a search of resistance genes involved in the production of ESBLs was performed using PCR: blaCMY-2, blaSHV-1, blaTEM-1, blaCTX-M2, blaOXA-1, blaPSE-1 and AmpC. The overall antimicrobial resistance was 80.55%. The highest levels of resistance were observed for nalidixic acid and ceftiofur (100%). The most commonly resistance pattern found (42.1%) was A (penicillin-cephalosporin-quinolone-tetracycline). The results were negative for ghost zone formation, indicative of ESBLs. However, PCR technique was able to detect resistance genes via ESBLs where the blaTEM-1 gene showed the highest amplification (83.33%), and the second most prevalent genes were blaCMY-2 (38.88%) and AmpC gene (38.88%). The blaOXA-1 and blaPSE-1 genes were not detected. These results are certainly of concern since SH is becoming more prevalent in the South of Brazil and able to cause severe disease in immune compromised individuals, showing high antimicrobial resistance to those drugs routinely used in the treatment and control of human and animal salmonellosis.

In vitro effect of seven essential oils on the reproduction of the cattle tick Rhipicephalus microplus.

The acaricidal effect of seven essential oils was examined in vitro against the cattle tick (Rhipicephalus microplus). Engorged female ticks were manually collected in farms of Southern Brazil and placed into petri dishes (n = 10) in order to test the following oils: juniper (Juniperus communis), palmarosa (Cymbopogon martinii), cedar (Cedrus atlantica), lemon grass (Cymbopogon citratus), ginger (Zingiber officinale), geranium (Pelargonium graveolens) and bergamot (Citrus aurantium var bergamia) at concentrations of 1%, 5%, and 10% each. A control group was used to validate the tests containing Triton X-100 only. Treatment effectiveness was measured considering inhibition of tick oviposition (partial or total), egg's weight, and hatchability. C. martinii, C. citratus and C. atlantica essential oils showed efficacy higher than 99% at all concentrations tested. In addition, J. communis, Z. officinale, P. graveolens, and C. aurantium var bergamia oils showed efficiency ranging from 73% to 95%, depending on the concentration tested, where higher concentrations showed greater efficacy. It was concluded that essential oils can affect tick reproduction in vitro by inhibiting oviposition and hatchability.

Trimming and washing poultry carcass to reduce microbial contamination: a comparative study.

The objective of this study was to compare the efficiency of washing and trimming broiler carcasses to reduce bacterial contamination. At the postevisceration site, 100 broiler carcasses were collected during 4 visits to a slaughterhouse in Santa Catarina State, Brazil. Birds were from the same flock, age, and approximately 2.4 kg of weight. Groups were as follows: group 1, with fecal contamination; group 2, without fecal contamination; group 3, with fecal contamination and trimmed; group 4, with fecal contamination and washed; group 5, with fecal contamination, and washed and trimmed. Carcass washings were performed with at least 1.5 L/bird of potable water (0.5 to 1 mg/kg of residual chlorine) at room temperature (20-25°C) using spray cabinets with 44 spray nozzles distributed into 2 chambers (pressure of 2 kgf/cm(2) and 4 kgf/cm(2)). Washed carcasses (trimmed or not) showed significantly (P < 0.05) lower counts of aerobic mesophiles (plate count agar) on the third evaluation, and even lower (P < 0.01) counts for total coliforms (CT) and fecal coliforms (Escherichia coli). Trimmed carcasses showed significantly lower counts (P < 0.05) for plate count agar; however, we observed higher counts for E. coli (P < 0.05). The association of both treatments (washing and trimming) showed significantly higher (P < 0.05) counts for coliforms (CT and E. coli). We can conclude that the washing method is overall more efficient than the trimming method to decontaminate chicken carcasses at the postevisceration site. Hopefully, our findings can help poultry companies to minimize production costs by applying the washing method for carcass decontamination.

Sources and levels of selenium on breast meat quality of broilers / Fontes e níveis de selênio sobre a qualidade da carne do peito de frangos de corte

Qualitative characteristics of breast meat of broilers fed diets supplemented with different concentrations (0; 0.3 and 0.5mg kg-1) of selenium in the form of selenomethionine and sodium selenite were analyzed. A total of 1050 one-day-old male Cobb broiler chicks were arranged factorially at random to five treatments (two concentrations x two sources + control diet without addition of selenium) with 7 replications of thirty birds each and received an isonitrogenous and isocaloric diets in all phases according to their ages (1-21, 22-35, and 36-42 days). At 42 days of age, TBARS (thiobarbituric acid reactive substances) after storage at 4ºC for one, seven and 15 days and also after 30 days under freezing temperatures (-15°C), color (CIELab), water holding capacity, cooking loss, shear force, pH and selenium concentration were determined in slaughtered birds breast meat. Results indicated that the use of selenomethionine provides less lightness and lower oxidation in chicken breast meat stored up to 15 days at 4°C. There was a positive effect of dietary different sources and levels of selenium on breast meat quality of broilers. It was observed a linear effect of dietary selenium levels on the amount of selenium deposited in the muscle, and the organic source (selenomethionine) is more effective than inorganic one (sodium selenite) for broiler meat conservation.

Analisaram-se características qualitativas da carne do peito de frangos de corte alimentados com rações suplementadas com diferentes concentrações (0; 0,3 e 0,5mg kg-1) de selênio nas formas de selenometionina e selenito de sódio. Foram utilizados 1050 pintainhos machos de um dia de idade da linhagem Cobb, que foram distribuídos em delineamento inteiramente casualizado em esquema fatorial em 5 tratamentos (duas concentrações x duas fontes + tratamento controle, sem adição de selênio) e sete repetições de trinta aves cada e receberam rações isoproteicas e isoenergéticas em todas as fases de criação (1 a 21, 22 a 35 e 36 a 42 dias). Aos 42 dias de idade, TBARS (substâncias reativas ao ácido tiobarbitúrico) após armazenamento a 4ºC por um, sete e 15 dias e 30 dias sob congelamento (15ºC), coloração (CIELab), capacidade de retenção de água, perdas de peso por cocção, força de cisalhamento, pH e concentração de selênio foram determinadas na carne do peito das aves abatidas. Os resultados indicaram que o uso da selenometionina ocasiona queda da oxidação da carne e luminosidade aos 15 dias de armazenamento a 4ºC. Existiu um efeito positivo da suplementação da ração com as diferentes fontes e concentrações de selênio sobre a qualidade da carne do peito das aves. Houve efeito linear dos níveis dietéticos de selênio na quantidade de selênio depositado no músculo, e a fonte orgânica (selenometionina) foi mais efetiva que a inorgânica (selenito de sódio) na conservação da carne de frango.

Pro-inflammatory cytokines in the serum of silver catfish (Rhamdia quelen) naturally infected by Clinostomum complanatum: a preliminary study.

Clinostomum complanatum is a zoonotic parasite of birds, and its larval form (metacercariae) may cause disease in fish. The immune response of fish infected by C. complanatum is unknown, and therefore the objective of this study was to evaluate serum levels of pro-inflammatory cytokines in silver catfish (Rhamdia quelen) infected by this parasite. The analysis showed that fish infected with metacercariae presented significantly (P < 0.05) higher levels of tumor necrosis factor alpha (TNF-α), interleukin 1 (IL-1), and interleukin 6 (IL-6) when compared to those not infected. These data suggest that C. complanatum larvae activate the host immune response.

Alphitobius diaperinus (Coleoptera: Tenebrionidae) susceptibility to Cunila angustifolia essential oil.

The lesser mealworm, Alphitobius diaperinus (Panzer), is an insect that lives in poultry houses, and high infestations may cause economic losses to producers. The control of this insect is usually done with insecticides; however, many of these chemicals have no effect on lesser mealworm. Therefore, control alternatives are needed. The aim of this study was to evaluate the influence of Cunila angustifolia (Benth) oil on larvae and adults of A. diaperinus. In vitro tests used larvae and adults of A. diaperinus distributed in petri dishes with 0, 1, 5, and 10% of oil in a single dose. In vivo tests were performed in poultry houses with five treatments: 0, 5, and 10% and chemical insecticide (cypermethrin) in a single application, and a group with 5% of oil applied twice 15 d apart. In vitro, oil bioactivity showed an efficacy of 100% both for larvae and adults, when tested at concentrations of 5 and 10%. A reduced number of larvae were observed using 1% of oil; however, it was not effective against adults as compared with the control group. In vivo, the oil effectiveness against lesser mealworm was verified by larva and adult reduction in all concentrations compared with control (0%) throughout the experiments, with better efficacy when used at 5% with two applications. Therefore, we concluded that the oil of C. angustifolia has larvicidal and insecticidal effect against A. diaperinus larvae and adults, in vitro and in vivo.

Occurrence of antibodies to Toxoplasma gondii in rheas (Rhea americana) and ostriches (Struthio camelus) from farms of different Brazilian regions.

This study aimed to verify the occurrence of antibodies against Toxoplasma gondii in rheas (Rhea americana) and ostriches (Struthio camelus) commercially breeding in Brazil. Blood samples from 20 rheas and 46 ostriches (young and adults) were serologically tested using a technique known as modified agglutination test (MAT) at an initial titration of 1:16 for ostriches and 1:25 for rheas. Antibodies against T. gondii were found in 50% (10/20) of the rheas, with titers ranging from 1:25 to 1:6,400. The incidence of antibodies against T. gondii in ostriches was 17.4% (8/46) with titers ranging from 1:16 to 1:256. Birds showing titers higher than 1:200 for T. gondii were mainly the young ones. Therefore, rheas and ostriches may be parasitized by T. gondii, showing high levels of antibodies against this parasite.

Occurrence of antibodies to Toxoplasma gondii in rheas (Rhea americana) and ostriches (Struthio camelus) from farms of different Brazilian regions / Ocorrência de anticorpos Toxoplasma gondii em emas (Rhea americana) e avestruzes (Struthio camelus) de propriedades de diferentes regiões brasileiras

This study aimed to verify the occurrence of antibodies against Toxoplasma gondii in rheas (Rhea americana) and ostriches (Struthio camelus) commercially breeding in Brazil. Blood samples from 20 rheas and 46 ostriches (young and adults) were serologically tested using a technique known as modified agglutination test (MAT) at an initial titration of 1:16 for ostriches and 1:25 for rheas. Antibodies against T. gondii were found in 50% (10/20) of the rheas, with titers ranging from 1:25 to 1:6,400. The incidence of antibodies against T. gondii in ostriches was 17.4% (8/46) with titers ranging from 1:16 to 1:256. Birds showing titers higher than 1:200 for T. gondii were mainly the young ones. Therefore, rheas and ostriches may be parasitized by T. gondii, showing high levels of antibodies against this parasite.

Este estudo teve como objetivo verificar a presença de anticorpos contra o Toxoplasma gondii em emas (Rhea americana) e avestruzes (Struthio camelus) criados comercialmente no Brasil. Amostras de sangue de 20 emas e 46 avestruzes (jovens e adultos) foram testadas sorologicamente pela técnica conhecida como teste de aglutinação modificada (MAT) em titulações iniciais de 1:16 para avestruzes e 1:25 para emas. Anticorpos contra T. gondii foram encontrados em 50% (10/20) das emas com títulos variando de 1:25 a 1:6.400. A incidência de anticorpos contra T. gondii em avestruzes foi de 17,4% (8/46) com os títulos oscilando entre 1:16 e 1:256. Aves jovens foram aquelas que apresentaram títulos superiores a 1:200 para T. gondii. Portanto, emas e avestruzes podem ser parasitados por T. gondii, apresentando elevados níveis de anticorpos contra o parasita.

Lice outbreak in buffaloes: evidence of Anaplasma marginale transmission by sucking lice Haematopinus tuberculatus.

Lice infestations are commonly seen in buffaloes, causing damage directly to the animal, i.e., itching, skin lesions, and anemia. In addition, these insects can also be vectors for infectious diseases. The present study describes an outbreak of lice in buffaloes as well as evidence for Haematopinus tuberculatus acting as a vector of anaplasmosis. Lice and blood were collected from 4 young buffaloes (2- to 4-mo-old) and a molecular analysis for the presence of Anaplasma marginale was conducted. DNA of A. marginale was detected in the blood of all 4 animals. Twelve lice were collected and separated in 4 groups, with 3 insects each, to comprise a pool of samples. After DNA extraction and molecular analysis, a positive PCR for A. marginale was found in all pooled samples. These results identify sucking lice as potential vectors of anaplasmosis. However, additional studies are necessary to fully evaluate the vector potential of H. tuberculatus for A. maginale transmission.