Neospora caninum in birds: A review

Neospora caninum is an obligate intracellular protozoan parasite that infects domestic and wild animals. Canids are considered to be definitive hosts since they may shed oocysts into the environment through their feces. The disease is recognized as one of the major causes of bovine abortion worldwide, leading to important economic losses in the dairy and beef cattle industries. Previous studies have reported N. caninum infection in different species of birds; infection in birds has been associated with increased seroprevalence and reproductive problems in dairy cattle. Although the role of birds in the epidemiological cycle of neosporosis is unknown, birds are exposed to infection because they feed on the ground and could thus contribute to parasite dissemination. This review is focused on the current state of knowledge of neosporosis in birds.     

Adiposity and Diabetes Risk in Adults with Prediabetes: Heterogeneity of Findings Depending on Age and Anthropometric Measure

Objective

The study aimed to evaluate the effect of age on diabetes incidence by general and central adiposity after 3‐year follow‐up in adults with prediabetes.

Methods

Data were taken from a cohort of 1,184 subjects with prediabetes included in The Cohort Study in Primary Health Care on the Evolution of Patients with Prediabetes (PREDAPS). General adiposity was defined using body mass index (BMI), and central adiposity was defined with waist circumference and waist to height ratio. Data were analyzed by age groups 30 to 59 and 60 to 74 years. The association between adiposity and diabetes incidence was assessed using hazard ratios (HR).

Results

Adjusting for sociodemographic characteristics, lifestyles, and metabolic parameters, diabetes HR for central adiposity based on the waist circumference clinical cutoff were 2.14 (1.12‐4.09) and 1.48 (0.80‐2.74) for people aged 30 to 59 and 60 to 74 years, respectively. In the model additionally adjusted for BMI, diabetes HR were 2.65 (1.24‐5.65) and 1.33 (0.68‐2.59), respectively. The use of a 1‐SD increase rather than cutoff points did not alter this pattern. Similar findings were observed with central adiposity based on waist to height ratio.

Conclusions

The association of central adiposity with type 2 diabetes incidence was lower for people in the older age group than for those in the younger age group.

     

Combined use of ELISA and Western blot with recombinant N protein is a powerful tool for the immunodiagnosis of avian infectious bronchitis

Background

The avian infectious bronchitis virus (IBV) remains a significant source of loss in the poultry industry and early diagnosis is required to prevent the disease from spreading. This study examined the combined use of an ELISA and Western blot (WB) to detect antibodies against the nucleocapsid protein (N) of IBV. The coding sequence for N was amplified by RT-PCR and expressed in Escherichia coli. A soluble recombinant N protein (rN) of approximately 50?kDa was obtained. A total of 389 sera were tested against the rN in ELISA and the results were compared with those of the commercial IDEXX IBV Ab test. ELISA-rN achieved a 90.34% sensitivity and 90.16% specificity. WB confirmed all false negative sera in ELISA-rN or IDEXX test as truly positive. The current study indicate that the combined use of rN in ELISA and WB is a powerful tool for the immunodiagnosis of avian infectious bronchitis.

Methods

Constructed recombinant pAE/n expression vectors were used to transform E. coli BL21(DE3) Star competent cells (Invitrogen). The rN of infectious bronchitis virus was purified by affinity chromatography using HisTrap HP 1?mL columns pre-packed with pre-charged Ni Sepharose in the ÄKTAprime Automated Liquid Chromatography system (GE Healthcare). A total of 389 serum samples from chickens were used to develop and evaluate the ELISA-rN test. To standardize the indirect ELISA development, serum dilutions (1:100, 1:200 and 1:400) and different concentrations of purified rN antigen (50, 100 and 200?ng/well) were tested. Positive and negative sera for IBV were used as controls. The results were compared with those obtained from a commercial kit. Serum samples scored as negative with the commercial kit but as positive with the ELISA-rN were further analysed by Western blot analyses using the rN protein as an antigen. The results of the ELISA-rN were compared to the commercial kit results using receiver-operating characteristics curves, area under the curve, and confidence intervals with the software GraphPad Prism version 6.0 for Windows (GraphPad Software, USA).

Results

The expected cDNA fragment of approximately 1240?bp was successfully amplified by PCR using primers designed to select for the coding region of the N protein. The rN was expressed as a soluble protein to avoid the refolding steps and, after purification a yield of 10?mg/L of rN was obtained. The SDS-PAGE results demonstrated the presence of two distinct bands that had a molecular mass of approximately 45 and 50 KDa. Out of 244 sera that scored positive in the commercial ELISA IDEXX IBV Ab Test, 220 were also positive in the ELISA-rN, yielding an ELISA-rN test sensitivity of 90.16%. Out of 145 sera that scored negative in the IDEXX IBV Ab Test, 131 also scored negative in the ELISA-rN, indicating a specificity of 90.34%. Sera that tested negative in the ELISA-rN and positive in the commercial test also reacted with the rN protein in Western blot.

Conclusions

The association between the ELISA and Western blot techniques developed in this study with a subunit of IBV (rN) were able to detect antibodies that the commercial ELISA did not detect suggesting that the ELISA-rN has greater sensitivity.

     

Stone tool use by wild capuchin monkeys (<Emphasis Type="Italic">Sapajus libidinosus</Emphasis>) at Serra das Confusões National Park,Brazil

Capuchin monkeys (Sapajus spp.) are proficient tool users, and the use of stone tools occurs in several populations, mostly to crack open encased foods. Two well-studied Brazilian populations of Sapajus libidinosus inhabit Fazenda Boa Vista and Serra da Capivara National Park and present different behavioral sets regarding tool use. Serra das Confusões National Park (SCoNP) lies between those sites, but little is known about the capuchin monkey population that lives there. To begin unraveling the capuchin behavior in this area, we conducted a brief survey for tool use sites. We found indirect evidence that capuchin monkeys at SCoNP use stone hammers to crack open at least four species of seeds and fruits. Plant reproductive parts there are processed with stone tools in a similar pattern to the other sites. Further study is needed to directly observe tool use by capuchin monkeys at SCoNP, verify the occurrence of other possible types of tool use in this population, and thus fully compare their tool use repertoire to that of other populations.     

Clinical strains of <Emphasis Type="Italic">Lactobacillus</Emphasis> reduce the filamentation of <Emphasis Type="Italic">Candida albicans</Emphasis> and protect <Emphasis Type="Italic">Galleria mellonella</Emphasis> against experimental candidiasis

Candida albicans is the most common human fungal pathogen and can grow as yeast or filaments, depending on the environmental conditions. The filamentous form is of particular interest because it can play a direct role in adherence and pathogenicity. Therefore, the purpose of this study was to evaluate the effects of three clinical strains of Lactobacillus on C. albicans filamentation as well as their probiotic potential in pathogen-host interactions via an experimental candidiasis model study in Galleria mellonella. We used the reference strain Candida albicans ATCC 18804 and three clinical strains of Lactobacillus: L. rhamnosus strain 5.2, L. paracasei strain 20.3, and L. fermentum strain 20.4. First, the capacity of C. albicans to form hyphae was tested in vitro through association with the Lactobacillus strains. After that, we verified the ability of these strains to attenuate experimental candidiasis in a Galleria mellonella model through a survival curve assay. Regarding the filamentation assay, a significant reduction in hyphae formation of up to 57% was observed when C. albicans was incubated in the presence of the Lactobacillus strains, compared to a control group composed of only C. albicans. In addition, when the larvae were pretreated with Lactobacillus spp. prior to C. albicans infection, the survival rate of G. mellonela increased in all experimental groups. We concluded that Lactobacillus influences the growth and expression C. albicans virulence factors, which may interfere with the pathogenicity of these microorganisms.     

Principles for Optimal Cooperativity in Allosteric Materials

Allosteric proteins transmit a mechanical signal induced by binding a ligand. However, understanding the nature of the information transmitted and the architectures optimizing such transmission remains a challenge. Here we show, using an in silico evolution scheme and theoretical arguments, that architectures optimized to be cooperative, which efficiently propagate energy, qualitatively differ from previously investigated materials optimized to propagate strain. Although we observe a large diversity of functioning cooperative architectures (including shear, hinge, and twist designs), they all obey the same principle of displaying a mechanism, i.e., an extended soft mode. We show that its optimal frequency decreases with the spatial extension L of the system as $L^{?d/2}$, where d is the spatial dimension. For these optimal designs, cooperativity decays logarithmically with L for d = 2 and does not decay for d = 3. Overall, our approach leads to a natural explanation for several observations in allosteric proteins and indicates an experimental path to test if allosteric proteins lie close to optimality.