In vitro and ex vivo anti-Pythium insidiosum potential of ozonated sunflower oil.

This study sought to evaluate the in vitro and ex vivo susceptibility of Pythium insidiosum to ozonized sunflower oil (OSO) and verify the morphological alterations of OSO-exposed hyphae. Susceptibility assays were performed according to the broth microdilution protocol M38-A2/CLSI, and the minimal inhibitory (MIC) and minimal oomicidal (MOC) concentrations were also determined. Non-ozonated sunflower oil (SO) was used as the oil control. Additionally, kunkers from equine pythiosis were exposed to OSO. Damages caused by OSO and SO on P. insidiosum hyphae ultrastructure were verified using scanning electron microscopy. The MIC range for OSO was 7000 to 437.5 mg/mL, and the values for SO were higher, ranging from 56000 to 14000 mg/mL. The MOC was equal to MIC for both oil formulations. The OSO fully inhibited the oomycete growth from kunkers, although there was P. insidiosum growth in the kunker control in 24 h of incubation. The SEM analyses showed that both OSO and SO caused morphological alterations in P. insidiosum hyphae, highlighting the presence of cavitation along the hyphae with loss of continuity of the cell wall, which was more evident in the OSO-treated hyphae. The OSO had the best oomicidal activity, leading us to believe that our findings may support future research containing this formulation to be applied in integrative medicine protocols to control pythiosis in animals and humans.

Identification of infection by Leishmania spp. in wild and domestic animals in Brazil: a systematic review with meta-analysis (2001-2021).

Leishmaniasis is a zoonosis caused by protozoan species of the genus Leishmania. It generates different clinical manifestations in humans and animals, and it infects multiple hosts. Leishmania parasites are transmitted by sandfly vectors. The main objective of this systematic review was to identify the host, or reservoir animal species, of Leishmania spp., with the exception of domestic dogs, that were recorded in Brazil. This review included identification of diagnostic methods, and the species of protozoan circulating in the country. For this purpose, a literature search was conducted across index journals. This study covered the period from 2001 to 2021, and 124 studies were selected. Eleven orders possible hosts were identified, including 229 mammalian species. Perissodactyla had the highest number of infected individuals (30.69%, 925/3014), with the highest occurrence in horses. In Brazil, the most commonly infected species were found to be: horses, domestic cats, rodents, and marsupials. Bats, that were infected by one or more protozoan species, were identified as potential reservoirs of Leishmania spp. Molecular tests were the most commonly used diagnostic methods (94 studies). Many studies have detected Leishmania spp. (n = 1422): Leishmania (Leishmania) infantum (n = 705), Leishmania (Viannia) braziliensis (n = 319), and Leishmania (Leishmania) amazonensis (n = 141). Recognizing the species of animals involved in the epidemiology and biological cycle of the protozoan is important, as this allows for the identification of environmental biomarkers, knowledge of Leishmania species can improve the control zoonotic leishmaniasis.

Prototheca bovis in goats: Experimental mastitis and treatment with polypyrrole.

Prototheca bovis has been associated with several cases of mastitis in cattle but no record of intramammary infections has been reported in goats. This infection does not respond to available treatments and the disposal recommendation of affected animals cause great damage to the dairy industry. Alternatives for dealing with infections caused by Prototheca spp. are required worldwide. In vitro results suggest polypyrrole as promising molecule for combating this alga, because an algaecide effect was observed on tested Prototheca spp. isolates. Thus, this study evaluated goats as an experimental model for intramammary infection by P. bovis and a protocol for treating these animals with an intramammary polypyrrole solution. The possibility of P. bovis promoting an intramammary infection in goats was experimentally proven, demonstrating this species as an important model for studies involving algae mastitis. Furthermore, polypyrrole reduced the counts of Prototheca sp. in the analyzed samples, showing potential to fight this microorganism also in vivo. The results obtained in this study demonstrate the ability of P. bovis to colonize breast tissue in lactating goats and the highly soluble molecule of polypyrrole has potential use for the treatment of protothecosis.

Direct and indirect nutritional factors that determine reproductive performance of heifer and primiparous cows.

Pregnancy rate is a major determinant of population dynamics of wild ungulates and of productivity of livestock systems. Allocation of feeding resources, including stocking rates, prior to and during the breeding season is a crucial determinant of this vital rate. Thus, quantification of effects and interaction among multiple factors that affect pregnancy rate is essential for management and conservation of pasture-based systems. Pregnancy rate of 2982 heifers and primiparous cows was studied as a function of animal category, average daily gain during the breeding season, stocking rate, pasture type and body weight at the beginning of the breeding season. Data were obtained from 43 experiments conducted in commercial ranches and research stations in the Pampas region between 1976 and 2015. Stocking rate ranged from 200 to 464 kg live weight ha-1, which brackets values for most of the grazinglands in similar regions. Age at breeding was 14-36 months (24.6±7.5 months); initial breeding weights were 129-506 kg and 194-570 kg for heifers and primiparous cows. Pregnancy rate was modeled with an apriori set of explanatory variables where proximate variables (breed, body weight at start of breeding, weight gain during breeding and category) were included first and subsequently modeled as functions of other variables (pasture type, supplementation and stocking rate). This modeling approach allowed detection of direct and indirect effects (through nutrition and body weight) of factors that affect pregnancy rate. Bos taurus breeds (N = 1058) had higher pregnancy rate than B. Taurus x B. indicus crossbreed (N = 1924) females. Pregnancy rate of heifers and primiparous cows grazing in natural grasslands decreased with increasing stocking rate, but no effect of stocking rate was detected in cultivated and improved pastures. Pregnancy rate increased with increasing average daily gain during the breeding season. Use of cultivated or improved natural pastures promotes higher pregnancy rate, as well as allows an increase in stocking rate at the regional level. Body weight at the start of the breeding season is the primary determinant of pregnancy rates in heifer and primiparous cows.

Melaleuca alternifolia formulations in the treatment of experimental pythiosis.

Essential oils (EO) are aromatic compounds from the plant secondary metabolism. Melaleuca alternifolia EO is well known for its medicinal properties and promising use as an antimicrobial agent. Pythiosis is a difficult-to-treat and emerging disease caused by the oomycete Pythium insidiosum. This study evaluated a nanoemulsion formulation of M. alternifolia (NEMA) in topical and intralesional application to treat experimental pythiosis. Dermal toxicity tests were performed on M. alternifolia EO in Wistar rats. Pythiosis was reproduced in rabbits (n = 9) that were divided into groups: group 1 (control), cutaneous lesions with daily topical application of a non-ionizable gel-based formulation and intralesional application of sterile distilled water every 48 h; group 2 (topical formulation), lesions treated daily with topical application of a non-ionizable gel-based formulation containing 5 mg/ml of NEMA; and group 3 (intralesional formulation), lesions treated with NEMA at 5 mg/ml in aqueous solution applied intralesionally/48 h. The animals were treated for 45 days, and the subcutaneous lesion areas were measured every 5 days. M. alternifolia EO showed no dermal toxicity. The lesion areas treated with intralesional NEMA reduced at the end of treatment, differing from groups 1 and 2 (P < 0.05). In the topically treated group, the lesion areas did not differ from the control group, although the number of hyphae significantly reduced (P < 0.05). Under the experimental conditions of this study, the NEMA formulations presented a favorable safety profile. However, further studies are required to evaluate if this safety applies to higher concentrations of NEMA and to validate its use in clinical pythiosis.

Occurrence of Leptospira spp. and factors associated with the infection in horses from a military contingent in the Rio Grande do Sul State, Brazil / Ocorrência de Leptospira spp. e fatores associados à infecção em equinos de contingente militar no estado do Rio Grande do Sul, Brasil

The seroprevalence of Leptospira spp. and infection risk factors were investigated in horses from a military contingent in the Rio Grande do Sul State, Brazil. A total of 446 horses were evaluated and categorized into 309 mares, 11 stallions, and 126 horses with an average age of three years. To determine seroprevalence, serum samples from all horses were submitted to the microscopic agglutination test against 12 serovars belonging to nine serogroups, usually circulating in equine populations. To investigate the possible risk factors of infection by Leptospira spp., questionnaires were applied in that military unit. The seroprevalence in the horses with an average age of 3 years, mares, and stallions were 57.94% (73/126), 54.05% (165/309), and 45.45% (5/11), respectively. The main risk factors identified were contact with different water sources, the presence of rodents, and contact with wild and domestic animals. The high seroprevalence of anti­Leptospira spp. antibodies may be associated with the presence of these risk factors. Therefore, the exposure of horses to possible reservoirs of Leptospira spp. should be minimized. Also, the immunoprophylaxis protocol should be reviewed and a shorter interval between vaccinations adopted to control leptospirosis in this herd.(AU)

A soroprevalência de Leptospira spp. e os fatores de risco para infecção foram investigados em cavalos de um contingente militar no Rio Grande do Sul, Brasil. Um total de 446 cavalos foram avaliados e categorizados em 309 éguas, 11 garanhões e 126 cavalos com idade média de três anos. Para determinação da soroprevalência, amostras de soro de todos os equinos foram submetidas ao teste de aglutinação microscópica contra 12 sorovares pertencentes a nove sorogrupos, normalmente circulantes em populações equinas. Para investigar os possíveis fatores de risco da infecção por Leptospira spp., foi aplicado um questionário naquela unidade militar. A soroprevalência nos cavalos com idade média de três anos, éguas e garanhões foi de 57,94% (73/126), 54,05% (165/309) e 45,45% (5/11), respectivamente. Os principais fatores de risco identificados foram o contato com diferentes fontes de água, a presença de roedores e o contato com animais silvestres e domésticos. A alta soroprevalência de anticorpos anti­Leptospira spp. pode estar associada à presença desses fatores de risco. Portanto, a exposição destes equinos aos possíveis reservatórios de Leptospira spp. deve ser minimizada. Além disso, o protocolo de imunoprofilaxia deve ser revisto e, possivelmente, um menor intervalo entre as vacinas deve ser adotado para o controle da leptospirose neste plantel.(AU)

In vitro lytic efficiency of Staphylococcus aureus bacteriophages in bacteria from bovine mastitis: a meta-analysis / Eficiência lítica in vitro de bacteriófagos de Staphylococcus aureus em bactérias de mastites bovina: uma meta-análise

ABSTRACT: Bacteriophages have been investigated as alternative to the treatment of bacterial infections, including bovine mastitis, in production animals. In this meta-analysis, we evaluated in vitro efficiency of phages of Staphylococcus aureus against S. aureus, which is involved in the etiology of bovine mastitis. Seventeen studies were included and the bacterial lytic activity was extracted using proportion analysis. The lytic efficiency of phages was obtained in this meta-analysis using a random-effects model [significant difference (P<0.05)]. Forest plots were used to graphically represent the efficiency of phages on bacterial isolates. Most phages (e.g., CS1, DW2, ΦSA011, ΦSA012, ΦSA022, ΦSA023, ΦSA024, ΦSA025, ΦSA037, ΦSA038, ΦSA039, ΦSA041, ΦSA042, ΦSA043, ΦSA044, MSA6, Ufv-aur2 to Ufv-aur11, SAH-1, SPW, vB_SauM_JS25, SaPh1 to SaPh6, SA, SANF, SA2, ΦSA012, ΦSA039, phi11, phiIPLA88, phiIPLA35, phiIPLA-RODI, phiIPLA-C1C, SAJK-IND, vBSP-A1, vBSP-A2, STA1.ST29, EB1.ST11, EB1.ST27, Remus, and ISP) were efficiently lytics or infected most S. aureus isolates, demonstrating 80% (P<0.05) lytic efficiency. The phages SA, SANF and SA2, also demonstrated lytic activity or infected the non-Staphylococcus aureus and Macrococcus caseolyticus isolates. In this meta-analysis, we compared and demonstrated the in vitro efficiency and host range of S. aureus phages. Additionally, the phages represent an alternative to be researched to treat bovine mastitis in dairy cattle caused by the prevalent microorganism, S. aureus.

RESUMO: Os bacteriófagos têm sido investigados como alternativa ao tratamento de infecções bacterianas em animais de produção, incluindo a mastite bovina. Nesta meta-análise, avaliamos a eficiência in vitro de fagos de Staphylococcus aureus contra S. aureus envolvidas na etiologia da mastite bovina. Dezessete estudos foram incluídos e a atividade lítica bacteriana foi extraída usando análise de proporção. A eficiência lítica dos fagos foi obtida nesta meta-análise, usando um modelo de efeitos aleatórios (diferença significativa (P <0,05)). Os gráficos de Forest plots foram usados para representar graficamente a eficiência dos fagos em isolados bacterianos. Os fagos avaliados, na sua grande maioria, (por exemplo, CS1, DW2, ΦSA011, ΦSA012, ΦSA022, ΦSA023, ΦSA024, ΦSA025, ΦSA037, ΦSA038, ΦSA039, ΦSA041, ΦSA042, ΦSA043, ΦSAf e U0f, ua04 SPW, vB_SauM_JS25, SaPh1 a SaPh6, SA, SANF, SA2, ΦSA012, ΦSA039, phi11, phiIPLA88, phiIPLA35, phiIPLA-RODI, phiIPLA-C1C, SAJK-IND, vBSP-A1, vBSP-A2, STA1.ST29, EB1.ST11, EB1.ST27, Remus, e ISP) foram eficientemente líticos ou infectaram a maioria dos isolados de S. aureus, demonstrando 80% (P < 0,05) de eficiência lítica. Os fagos SA, SANF e SA2 também demonstraram atividade lítica ou infectaram os isolados Staphylococcus não-aureus e Macrococcus caseolyticus. Nesta meta-análise, comparamos e demonstramos a eficiência in vitro e gama de hospedeiros de fagos de S. aureus. Adicionalmente, os fagos representam uma alternativa a ser pesquisada para o tratamento da mastite bovina em gado leiteiro causada pelo microrganismo prevalente, ou seja S. aureus.

Purpureocillium lilacinum and Trichoderma virens for biological control of trichostrongylid parasites of sheep: an in vitro evaluation.

The study evaluated the ovicidal activity of enzymatic extracts of Purpureocillium lilacinum and Trichoderma virens against trichostrongylid eggs from sheep. Filtered extract (FE) and macerated crude extract (MCE) were prepared from fungal cultures in minimal broth. In the experiment, 100 trichostrongylid eggs, obtained from the feces of naturally infected sheep, were exposed to fungal extracts for 24 and 48 hours/25°C. In the control group, eggs were incubated in minimal broth. The number of L1 larvae was ascertained. Each treatment consisted of four repetitions and the experiment was repeated five times. It was observed that the effect of FE and MCE of P. lilacinum and T. virens on egg hatchability differed from that of the control group. MCE of T. virens and P. lilacinum showed higher ovicidal activity than FE over both periods and at 48 hours of exposure, respectively. From the percentage reductions in hatchability of the eggs, MCE was shown to be superior to FE for both fungi. This study demonstrated the ovicidal potential of these fungi against trichostrongylid eggs. However, further studies are needed in order to identify the molecules responsible for the ovicidal effects, and to evaluate the behavior of fungal extracts in biotic and abiotic interactions.

Biogenic silver nanoparticles in the treatment of experimental pythiosis Bio-AgNP in pythiosis therapy.

Pythiosis is a rapidly progressing disease that can be lethal to affected individuals due to resistance to available therapeutic protocols. The disease affects mammals, with the largest number of reports in horses and humans. The present study investigated the activity of biogenic silver nanoparticles (bioAgNP) in the treatment of experimental pythiosis. The disease was reproduced in nine female 90-day-old New Zealand rabbits. Animals were divided into three groups: group1 (control, n = 3) daily and topically treated with a nonionized gel-based formulation and 1 ml of sterile distilled water intralesion administered every 48 hours; group 2 (n = 3), daily and topically treated with gel-based formulation containing 1 µg/ml bio-AgNP; group 3 (n = 3), treated with 1 ml bio-AgNP in 1 µg/ml aqueous solution intralesion administered every 48 hours. Animals were treated for 45 days, and the area of subcutaneous lesions was measured every 5 days. Results showed that groups 2 and 3 differed from control group (P < .05) in the lesion area, as well as the amount of hyphae within the lesions. It was observed that lesions of treated animals (groups 2 and 3) did not differ from each other, showing that the application route did not influence the regression of lesions. However, it was observed that one animal from group 2 reached clinical cure at 35 days of treatment. This research is pioneer in the application of nanocomposites for the treatment of experimental pythiosis and showed that bio-AgNP can be powerful allies of integrative medicine and can be included in pythiosis therapeutic protocols.

Purpureocillium lilacinum and Trichoderma virens for biological control of trichostrongylid parasites of sheep: an in vitro evaluation / Purpureocillium lilacinum e Trichoderma virens no controle biológico de tricostrongilídeos de ovinos: uma avaliação in vitro

Abstract The study evaluated the ovicidal activity of enzymatic extracts of Purpureocillium lilacinum and Trichoderma virens against trichostrongylid eggs from sheep. Filtered extract (FE) and macerated crude extract (MCE) were prepared from fungal cultures in minimal broth. In the experiment, 100 trichostrongylid eggs, obtained from the feces of naturally infected sheep, were exposed to fungal extracts for 24 and 48 hours/25°C. In the control group, eggs were incubated in minimal broth. The number of L1 larvae was ascertained. Each treatment consisted of four repetitions and the experiment was repeated five times. It was observed that the effect of FE and MCE of P. lilacinum and T. virens on egg hatchability differed from that of the control group. MCE of T. virens and P. lilacinum showed higher ovicidal activity than FE over both periods and at 48 hours of exposure, respectively. From the percentage reductions in hatchability of the eggs, MCE was shown to be superior to FE for both fungi. This study demonstrated the ovicidal potential of these fungi against trichostrongylid eggs. However, further studies are needed in order to identify the molecules responsible for the ovicidal effects, and to evaluate the behavior of fungal extracts in biotic and abiotic interactions.

Resumo O estudo avaliou a atividade ovicida de extratos enzimáticos de Purpureocillium lilacinum e Trichoderma virens sobre ovos de tricostrongilídeos de ovinos. Extrato filtrado (EF) e extrato macerado bruto (EMB) foram preparados a partir de culturas fúngicas em caldo mínimo. No ensaio experimental, 100 ovos de tricostrongilídeos, obtidos de fezes de ovinos naturalmente infectados, foram expostos durante 24 e 48 horas/25ºC aos extratos dos fungos. No grupo controle, os ovos foram incubados em caldo mínimo. O número de larvas L1 foi determinado. Cada tratamento consistiu em quatro repetições e o experimento foi repetido cinco vezes. Observou-se que o efeito ovicida do EF e EMB de P. lilacinum e T. virens diferiu do grupo controle. O EMB de T. virens e P. lilacinum evidenciou atividade ovicida superior ao EF em ambos os períodos avaliados e em 48 horas de exposição, respectivamente. O percentual de redução de eclodibilidade evidenciou que o EMB foi superior ao EF em ambos os fungos. Este estudo demonstra o potencial ovicida desses fungos sobre ovos de tricostrongilídeos. No entanto, estudos adicionais são necessários para identificar as moléculas responsáveis pelo efeito ovicida, bem como avaliar o comportamento dos extratos fúngicos em interações bióticas e abióticas.

Canopy structure and morphogenesis of Italian ryegrass intercropped with red clover under cutting intervals determined by thermal sum / Estrutura do dossel e morfogênese do azevém anual consorciado com trevo vermelho em intervalos de corte determinados por soma térmica

ABSTRACT: The canopy structure and morphogenesis of ryegrass (Lolium multiflorum Lam.) was investigated after it was over seeded with Tifton 85 (Cynodon spp.) and intercropped with red clover (Trifolium pratense L.). Time intervals between cuts were determined by different thermal sums (125, 250, 375, and 500 degree-days [DD]). Cuts were conducted at a height equivalent to 50% of the average canopy height. Morphogenic and structural data were collected from July to October of 2016 and 2017, from a completely randomized block experimental design. Canopy height, extended tiller height, pseudostem length, and forage mass were fitted to linear equations according to the thermal sums. Interaction of ryegrass with red clover was the highest (12.1%) for longer cut intervals (375 and 500 DD). The leaf appearance rate (0.0080 leaf/DD), phyllochron value (128.8 DD), and senescence rate (0.10 cm/DD) of ryegrass were comparable between the different intervals. The slowest elongation rate (0.06 cm/DD) with the shortest interval duration between cuts (171.6 DD) was observed in the 125 DD interval. According to the findings from this 2-year experiment, the use of a 250 DD cut interval was recommended between grazing events, taking into account the efficiency of forage use, ryegrass leaf, stem ratio, and interactions with red clover in the canopy under rotational stocking.

RESUMO: A estrutura do dossel e a morfogênese do azevém (Lolium multiflorum Lam.) foram investigadas após a sobressemeadura em Tifton 85 (Cynodon spp.) e consorciado com trevo vermelho (Trifolium pratense L.). Os intervalos de tempo entre os cortes foram determinados por diferentes somas térmicas (125, 250, 375 e 500 graus-dia [GD]). Os cortes foram realizados a uma altura equivalente a 50% da altura média do dossel. Os dados morfogênicos e estruturais foram coletados no período de julho a outubro de 2016 e 2017, em um delineamento experimental de blocos ao acaso. A altura do dossel, a altura estendida do perfilho, o comprimento do pseudocolmo e a massa de forragem se ajustaram a equações lineares de acordo com a soma térmica. A consorciação de azevém e trevo vermelho foi maior (12,1%) para intervalos de corte mais longos (375 e 500 GD). A taxa de aparecimento foliar (0,0080 folha/GD), filocrono (128,8 GD) e a taxa de senescência (0,10 cm /GD) do azevém não foram diferentes entre os intervalos de corte. A menor taxa de elongação (0,06 cm/GD) e duração de elongação (171,6 GD) foi observada no menor intervalo entre cortes, 125 GD. De acordo com os achados deste experimento de dois anos, recomenda-se o uso de um intervalo de corte de 250 GD entre os eventos de pastejo, levando em consideração a eficiência do uso de forragem, proporção de folhas e colmo de azevém e trevo vermelho no dossel, sob lotação rotativa.

Clinical and Pathological Aspects of Canine Cutaneous Leishmaniasis: A Meta-analysis.

PURPOSE: In the present study, we described the most prevalent clinical symptoms, the most affected organs, and the macro and microscopic lesions associated with cutaneous leishmaniasis. METHODS: Two independent researchers performed an extensive systematic review of the literature in four stages (identification, screening, eligibility, and inclusion) to identify studies published between January 2002 and November 2018 from the following electronic databases: Web of Science, PubMed, SciELO, Science Direct, and Google Scholar. Meta-analysis was conducted in "Metaprop" package of R 3.4.2 software. RESULTS: The electronic search yielded 3896 results, out of which 155 were further analyzed based on the full-text. Data extracted from 16 articles were included in the meta-analysis, representing a total of 430 leishmaniasis cases. Only 43% of all animals were identified to exhibit the clinical and cutaneous changes characteristic of leishmaniasis based on the observation that skin lesions were the most prevalent clinical sign and were present in 86% of all cases. Other less prevalent symptoms included weight loss, cachexia, apathy and lymph node enlargement. Histopathological analysis showed that the skin was the most affected organ, affecting 64% of cases, followed by lymph nodes (12%), spleen (8%) and liver (7%). CONCLUSIONS: Therefore, our current findings suggest that cutaneous leishmaniasis could lead to visceral disease. Notably, our findings indicated no clinical manifestation patterns in cutaneous leishmaniasis, since the same host species may present different clinical conditions.

Exposure of Toxocara canis eggs to Purpureocillium lilacinum as a biocontrol strategy: an experimental model evaluation.

Purpureocillium lilacinum is a nematophagous fungus used in biological control against some parasites, including Toxocara canis. This study researched the infectivity of embryonated T. canis eggs after exposure to the fungus P. lilacinum. T. canis eggs were exposed to P. lilacinum for 15 or 30 days and subsequently administered to Swiss mice (n=20). Control group consisted of mice who received T. canis embryonated eggs without fungal exposure. Forty-eight hours after infection, heart, lung, and liver from animals of each group were collected to assess larval recovery. The organs of mice that received embryonated eggs exposed to the fungus showed a lower average larval recovery (P<0.05) suggesting that exposure of T. canis eggs to P. lilacinum was able to reduce experimental infection. Under the evaluated conditions, the interaction time between the fungus and the parasite eggs was not a significant factor in larvae recovery. P. lilacinum may be considered a promising T. canis biological control agent. However, further studies are needed to determine a protocol for the use of this fungus as a biological control agent.

Exposure of Toxocara canis eggs to Purpureocillium lilacinum as a biocontrol strategy: an experimental model evaluation / Exposição de ovos de Toxocara canis a Purpureocillium lilacinum como estratégia de biocontrole: uma avaliação em modelo experimental

Abstract Purpureocillium lilacinum is a nematophagous fungus used in biological control against some parasites, including Toxocara canis. This study researched the infectivity of embryonated T. canis eggs after exposure to the fungus P. lilacinum. T. canis eggs were exposed to P. lilacinum for 15 or 30 days and subsequently administered to Swiss mice (n=20). Control group consisted of mice who received T. canis embryonated eggs without fungal exposure. Forty-eight hours after infection, heart, lung, and liver from animals of each group were collected to assess larval recovery. The organs of mice that received embryonated eggs exposed to the fungus showed a lower average larval recovery (P<0.05) suggesting that exposure of T. canis eggs to P. lilacinum was able to reduce experimental infection. Under the evaluated conditions, the interaction time between the fungus and the parasite eggs was not a significant factor in larvae recovery. P. lilacinum may be considered a promising T. canis biological control agent. However, further studies are needed to determine a protocol for the use of this fungus as a biological control agent.

Resumo Purpureocillium lilacinum é um fungo nematófago com potencial para uso no controle biológico de parasitos, incluindo Toxocara canis. Este estudo pesquisou a infectividade de ovos de T. canis embrionados após exposição ao fungo P. lilacinum . Ovos de T. canis foram expostos ao fungo por 15 ou 30 dias e subsequentemente administrados a camundongos Swiss (n=20). O grupo controle consistiu de camundongos que receberam ovos embrionados do parasita sem exposição ao fungo. Quarenta e oito horas após a infecção, coração, pulmão e fígado dos camundongos foram coletados para avaliar a recuperação larval. Os órgãos dos animais que receberam ovos embrionados expostos ao fungo apresentaram menor média de recuperação larval (P<0,05) do que os infectados com ovos sem exposição ao fungo, sugerindo que a exposição dos ovos de T. canis a P. lilacinum foi capaz de reduzir a infecção experimental. Nas condições avaliadas, o tempo de interação entre o fungo e os ovos do parasito não foi um fator significativo na recuperação das larvas. P. lilacinum pode ser considerado um promissor agente de controle biológico de T. canis, no entanto, mais estudos são necessários para avaliar o emprego deste fungo como um agente de controle biológico.

Effect of herbage allowances on biomass flows in Italian ryegrass / Efeito de ofertas de forragem sobre o fluxo de biomassa em azevém

ABSTRACT: The objective of this study was to determine the leaf tissue flows in Italian ryegrass (Lolium multiflorum Lam.), in different phenological stages, grazed by lambs, and managed under three herbage allowances (6, 9 and 12 kg DM/100 kg body weight under rotational stocking method. The experimental design was completely randomized, with repeated measures arrangement. Forage allowances determined similar growth and intake flows, actual and potential utilization efficiencies of grass and they were different in the phenological stages of Italian ryegrass. The intake of leaf blade, as a percentage of body weight, was higher in the 12% herbage allowance. Considering leaf tissue flows, Italian ryegrass can be managed in forage allowances that vary between 6 and 12 kg DM/100 kg body weight.

RESUMO: Este trabalho foi conduzido com o objetivo de determinar os fluxos de tecidos foliares em diferentes estádios fenológicos do azevém (Lolium multiflorum Lam.), pastejado por cordeiras, manejado sob três níveis de oferta de forragem (6; 9 e 12 kg de MS/100 kg de peso corporal), sob lotação intermitente. O delineamento experimental foi inteiramente casualizado, com medidas repetidas no tempo. Os fluxos de crescimento e consumo de lâminas foliares, as eficiências real e potencial de utilização do pasto foram similares nas ofertas de forragem e diferentes nos estádios fenológicos do azevém. O consumo de lâminas foliares em porcentagem do peso corporal foi superior na oferta de forragem 12%. Considerando os fluxos de tecidos foliares, o azevém pode ser manejado com ofertas de forragem que variam entre 6 a 12 kg de MS/100 kg de peso corporal.

Economic viability of anthelmintic treatment in naturally infected beef cattle under different nutritional strategies after weaning.

The aim of the present study was to evaluate the effects of treatment with different anthelmintic compounds on the productivity of naturally infected calves and the economic viability of these treatments within extensive breeding systems employing different nutritional strategies after weaning. For this purpose, 4 farms with 42-60 calves naturally infected with gastrointestinal nematodes were selected. The calves were distributed into 6 groups (7-10 animals each) per farm and treated with ivermectin 1%, ivermectin 3.15%, eprinomectin 5%, levamisole 7.5%, albendazole 15%, and control group (no treatment). These animals were evaluated over an experimental period of 150 days. Levamisole 7.5% presented the best capacity for the reduction of eggs per gram (EPG) of feces in all herds evaluated, followed by albendazole 15% and eprinomectin 5%. Parasite resistance to multiple drugs was found in all herds, especially those of Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. For farm 1, differences in weight gain and EPG reduction percentages led to a difference of US$285.06 between the levamisole and ivermectin 3.15% groups. Similar findings were noted for the levamisole and ivermectin 1% groups of farm 3, with a difference of US$399.37 because of the final weight gain in these groups. For farms 2 and 4, the ivermectin 3.15% and control groups, respectively, were the most profitable; these unexpected results were possibly influenced by variables not measured during the experimental period. This study suggested that anthelmintic treatments should always precede an efficacy test, once they are demonstrated to be most profitable under adequate breeding conditions, to ensure adequate control of gastrointestinal nematode infection.

Ingestive behavior and forage intake of heifers receiving corn grain with or without crude glycerin on italian ryegrass pasture / Comportamento ingestivo e ingestão de forragem por bezerras recebendo grão de milho com ou sem glicerina bruta em pastagem de azevém

The objective was to analyze the ingestive behavior, forage intake and pasture characteristics when beef heifers are kept exclusively on ryegrass pasture (Lolium multiflorum Lam.) or receiving ground corn grain as supplement (0.9% of body weight (BW )) with or without addition of crude glycerin (0.2% BW). Experimental animals were Angus heifers with initial age and body weight of eight months and 166.2 ± 9.5 kg, respectively. The grazing method was continuous with variable number of animals. The experimental design was completely randomized with repeated measures. Dry matter intake was estimated using chromium oxide as an indicator of fecal output. Heifers ingested a similar amount of dry matter and neutral detergent fiber. Forage intake was 19.0% lower when heifers receiving ground corn grain as supplement with or without addition of crude glycerin and these reduction in dry matter intake of forage provided increase of 38.2% in the stocking rate. Heifers that received crude glycerin as a supplement spent more time in the trough than heifers that received only ground corn grain.

Objetivou-se avalizar o comportamento ingestivo, ingestão de forragem e as características da pastagem quando bezerras de corte são mantidas exclusivamente em pastagem de azevém (Lolium multiflorum Lam.) ou recebendo grão de milho quebrado como suplemento (0,9% do peso corporal (PC)) com ou sem adição de glicerina bruta (0,2% PC). Os animais experimentais foram bezerras Angus com idade e peso inicial de oito meses e 166,2 ± 9,5 kg, respectivamente. O método de pastejo foi o contínuo com número variável de animais. O delineamento experimental foi o inteiramente casualizado com medidas repetidas no tempo. A ingestão de matéria seca foi estimada usando óxido de cromo como indicador de produção fecal. As bezerras ingeriram similares quantidades de matéria seca e fibra em detergente neutro. A ingestão de forragem foi 19.0% menor quando as bezerras recebem grão de milho quebrado como suplemento com ou sem adição de glicerina bruta e essa redução na ingestão de matéria seca de forragem promove aumento de 38,2% na taxa de lotação. Bezerras que recebem glicerina bruta como suplemento permanecem mais tempo no cocho do que bezerras que recebem somente grão de milho quebrado.

Effect of Paecilomyces lilacinus, Trichoderma harzianum and Trichoderma virens fungal extracts on the hatchability of Ancylostoma eggs / Efecto de los extractos de los hongos Paecilomyces lilacinus, Trichoderma harzianum y Trichoderma virens en la eclosionabilidad de huevos de Ancylostoma

Background. Ancylostoma species have demanded attention due to their zoonotic potential. The use of anthelmintics is the usual method to prevent environmental contamination by Ancylostoma eggs and larvae. Nematophagous fungi have been widely used in their biological control due to the fungus ability to capture and digest free nematode forms. Aims. The aim of this study was to evaluate the effect of four different fungal extracts of Paecilomyces lilacinus (n=2), Trichoderma harzianum (n=1) and Trichoderma virens (n=1) isolates on the hatchability of Ancylostoma eggs. Methods. Fungal extracts consisted of fungal broth culture supernatant without filtration (crude extract) and filtered broth (filtered extract), macerated mycelium (crude macerate), and macerated mycelium submitted to filtration (filtered macerate). The Ancylostoma eggs were obtained from the feces of naturally infected dogs. In vitro assays were performed in five replicates and consisted of four treatments and one control group. Results. The activity of the fungal extracts of each evaluated fungus differed (p<0.05) from those of the control group, showing significant ovicidal activity. The hatching of the eggs suffered reduction percentages of 68.43% and 47.05% with P. lilacinus, and 56.43% with T. harzianum, when crude macerate extract was used. The reduction with the macerate extract of T. virens was slightly lower (52.25%) than that for the filtered macerate (53.64%). Conclusions. The results showed that all extracts were effective in reducing the hatchability of Ancylostoma eggs. The ovicidal effect observed is likely to have been caused by the action of hydrolytic enzymes secreted by the fungi (AU)

Antecedentes. Las especies del género Ancylostoma son de gran importancia debido a su potencial zoonótico. El uso de antihelmínticos es el método habitual en la prevención de la contaminación ambiental por huevos y larvas del género Ancylostoma. Los hongos nematófagos se utilizan ampliamente en el control biológico de aquellos, debido a su capacidad de capturar y digerir nematodos libres. Objetivo. El objetivo del estudio fue evaluar el efecto de cuatro extractos diferentes de hongos (Paecilomyces lilacinus [n=2], Trichoderma harzianum [n=1] y Trichoderma virens [n=1]) en la eclosionabilidad de huevos de especies de Ancylostoma. Métodos. Los extractos de hongos constaban del sobrenadante del cultivo en caldo fúngico sin filtración (extracto crudo) y caldo filtrado (extracto filtrado), micelio macerado (macerado crudo) y micelio macerado sometido a filtración (macerado filtrado). Los huevos de Ancylostoma se obtuvieron a partir de heces de perros infectados de manera natural. Se realizaron cinco repeticiones de los ensayos in vitro con cuatro tratamientos y un grupo control. Resultados. La actividad de los extractos fúngicos de cada hongo evaluado difiere (p<0,05) de la de aquellos del grupo control, lo que demuestra una actividad ovicida significativa. Con el extracto crudo macerado, la reducción de la eclosión mostró porcentajes del 68,43 y el 47,05% en el caso de P. lilacinus y del 56,43% para el caso de T. harzianum. El porcentaje de reducción en el uso del macerado crudo en T. virens fue del 52,25%, algo inferior respecto al macerado filtrado (53,64%). Conclusiones. Los resultados mostraron que todos los extractos fueron eficaces en la reducción de la eclosionabilidad de huevos de Ancylostoma. Es probable que el efecto ovicida observado haya sido causado por la acción de enzimas hidrolíticas secretadas por los hongos (AU)

Trichoderma virens as a biocontrol of Toxocara canis: In vivo evaluation / Trichoderma virens como control biológico de Toxocara canis: evaluación in vivo

Background. Microorganisms have been widely studied as biological control agents of parasites of medical and veterinary importance. Coprophagous arthropods, bacteria and fungi are among the different organisms evaluated as potential biological control agents. Nematophagous fungi capture and digest the free forms of nematodes in the soil. Due to its zoonotic potential, Toxocara canis have been brought to the attention of researchers. Aims. The aim of the present study was to determine whether the administration of embryonated T. canis eggs exposed to the nematophagous fungus Trichoderma virens reduces parasite infection in experimental animals. Methods. Embryonated T. canis eggs were exposed to T. virens mycelium for 15 days at 25°C. Subsequently, 100 fungus-exposed eggs were orally administered to 20 Swiss mice. As a positive control, another 20 mice received 100 embryonated eggs that were not exposed to the fungus. After 48h, the animals were killed, and heart, lungs and liver were harvested for the recovery of larvae. Results. The organs of the animals that received embryonated T. canis eggs exposed to the fungus showed a lower mean larval recovery when compared with the animals that received embryonated eggs without fungus exposure (p<0.05). Conclusions. The exposure of T. canis eggs to T. virens reduces the experimental infection, demonstrating the potential of this nematophagous fungus as a biocontrol agent (AU)

Antecedentes. Algunos microorganismos han sido ampliamente estudiados como agentes de control biológico de parásitos de importancia médica y veterinaria. Los artrópodos coprófagos, las bacterias y los hongos están entre los diferentes organismos que sirven como agentes para el control con potencial biológico. Los hongos nematófagos capturan y digieren las formas libres de nematodos en el suelo. Toxocara canis, debido a su potencial zoonótico, ha captado la atención de los investigadores en estos estudios. Objetivos. El objetivo del presente estudio fue evaluar si la exposición de huevos embrionados de T. canis al hongo nematófago Trichoderma virens reduce la infección parasítica en un modelo experimental animal. Métodos. Los huevos embrionados de T. canis fueron expuestos al micelio de T. virens durante 15días a 25°C. Posteriormente, 100huevos de T. canis expuestos al hongo fueron administrados por vía oral a un grupo de 20ratones Swiss. Como control positivo se usó otro grupo de 20ratones que recibieron 100huevos embrionados no expuestos al hongo. Después de 48h, los animales fueron sacrificados y corazón, pulmones e hígado fueron extraídos para la posterior obtención de larvas. Resultados. El número de larvas obtenidas en los diferentes órganos fue menor en el grupo de animales que fueron infectados con los huevos embrionados de T. canis expuestos al hongo en comparación con el grupo de animales que recibieron huevos embrionados sin la exposición al hongo (p<0,05). Conclusiones. La exposición de los huevos de T. canis a T. virens reduce la infección experimental, lo que demuestra el potencial de este hongo nematófago como agente para el control biológico (AU)

Trichoderma virens as a biocontrol of Toxocara canis: In vivo evaluation.

BACKGROUND: Microorganisms have been widely studied as biological control agents of parasites of medical and veterinary importance. Coprophagous arthropods, bacteria and fungi are among the different organisms evaluated as potential biological control agents. Nematophagous fungi capture and digest the free forms of nematodes in the soil. Due to its zoonotic potential, Toxocara canis have been brought to the attention of researchers. AIMS: The aim of the present study was to determine whether the administration of embryonated T. canis eggs exposed to the nematophagous fungus Trichoderma virens reduces parasite infection in experimental animals. METHODS: Embryonated T. canis eggs were exposed to T. virens mycelium for 15 days at 25°C. Subsequently, 100 fungus-exposed eggs were orally administered to 20 Swiss mice. As a positive control, another 20 mice received 100 embryonated eggs that were not exposed to the fungus. After 48h, the animals were killed, and heart, lungs and liver were harvested for the recovery of larvae. RESULTS: The organs of the animals that received embryonated T. canis eggs exposed to the fungus showed a lower mean larval recovery when compared with the animals that received embryonated eggs without fungus exposure (p<0.05). CONCLUSIONS: The exposure of T. canis eggs to T. virens reduces the experimental infection, demonstrating the potential of this nematophagous fungus as a biocontrol agent.