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Usutu virus (USUV) is a flavivirus transmitted to avian species through mosquito bites that causes mass mortalities in wild and captive bird populations. However, several cases of positive dead birds have been recorded during the winter, a vector-free period. To explain how USUV "overwinters", the main hypothesis is bird-to-bird transmission, as shown for the closely related West Nile virus. To address this question, we experimentally challenged canaries with intranasal inoculation of USUV, which led to systemic dissemination of the virus, provided the inoculated dose was sufficient (>10 2 TCID 50 ). We also highlighted the oronasal excretion of infectious viral particles in infected birds. Next, we co-housed infected birds with naive sentinels, to determine whether onward transmission could be reproduced experimentally. We failed to detect such transmission but demonstrated horizontal transmission by transferring sputum from an infected to a naive canary. In addition, we evaluated the cellular tropism of respiratory mucosa to USUV in vitro using a canary tracheal explant and observed only limited evidence of viral replication. Further research is then needed to assess if and how comparable bird-to-bird transmission occurs in the wild.

Mx proteins are key factors of the innate intracellular defense mechanisms that act against viruses induced by type I/III interferons. The family Peribunyaviridae includes many viruses of veterinary importance, either because infection results in clinical disease or because animals serve as reservoirs for arthropod vectors. According to the evolutionary arms race hypothesis, evolutionary pressures should have led to the selection of the most appropriate Mx1 antiviral isoforms to resist these infections. Although human, mouse, bat, rat, and cotton rat Mx isoforms have been shown to inhibit different members of the Peribunyaviridae, the possible antiviral function of the Mx isoforms from domestic animals against bunyaviral infections has, to our knowledge, never been studied. Herein, we investigated the anti-Schmallenberg virus activity of bovine, canine, equine, and porcine Mx1 proteins. We concluded that Mx1 has a strong, dose-dependent anti-Schmallenberg activity in these four mammalian species.

The main objective of this study was to create a mathematical tool that could be used with experimental data to predict the rheological flow behavior of functionalized xanthan gum according to the types of chemical groups grafted onto its backbone. Different rheological and physicochemical analyses were applied to assess six derivatives synthesized via the etherification of xanthan gum by hydrophobic benzylation with benzyl chloride and carboxymethylation with monochloroacetic acid at three (regent/polymer) ratios R equal to 2.4 and 6. Results from the FTIR study verified that xanthan gum had been modified. The degree of substitution (DS) values varying between 0.2 and 2.9 for carboxymethylxanthan gum derivatives were found to be higher than that of hydrophobically modified benzyl xanthan gum for which the DS ranged from 0.5 to 1. The molecular weights of all the derivatives were found to be less than that of xanthan gum for the two types of derivatives, decreasing further as the degree of substitution (DS) increased. However, the benzyl xanthan gum derivatives presented higher molecular weights varying between 1,373,146 (g/mol) and 1,262,227 (g/mol) than carboxymethylxanthan gum derivatives (1,326,722-1,015,544) (g/mol). A shear-thinning behavior was observed in the derivatives, and the derivatives' viscosity was found to decrease with increasing DS. The second objective of this research was to create an ANN model to predict one of the rheological properties (the apparent viscosity). The significance of the ANN model (R 2 = 0.99998 and MSE = 5.95 × 10 -3 ) was validated by comparing experimental results with the predicted ones. The results showed that the model was an efficient tool for predicting rheological flow behavior.

This study aimed to describe the bacterial composition of the surgical site during elective caesarean sections (CSs) using the 16Sr DNA amplicon sequencing performed in parallel to bacterial culture. The study involved 13 Belgian blue cows of a previous dataset of 76 animals. Bacteriology was performed on swabs sampled from visceral and parietal peritoneum during the CS. Amplicon sequencing was performed in six samples chosen randomly among the swabs positive for bacteriology and seven among the culture-negative swabs. A total of 2542 bacterial operational taxonomic units belonging to 567 genera were identified. The most often identified genus and species were Mycoplasma (44%) and Mycoplasma wenyonii (36%), respectively. Results showed no difference in microbiota composition between the culture-positive and -negative samples. However, a difference was observed between the bacteriology and amplicon sequencing results. Indeed, seven out of nine cultured strains were not identified by amplicon sequencing in the samples in which they were cultured. In contrast to bacteriology, amplicon sequencing unveiled the presence of bacterial DNA in all elective CSs. The most identified DNA is most likely derived from the haematogenous spread of bacteria to the surgical site. Furthermore, the cultured bacteria were not the dominant species in the sample from which they were cultured.

To improve the efficacy of preoperative antibiotics used in elective caesarean section (CS), we aimed to identify the bacteria contaminating the surgical site during this surgery. A study was conducted on 76 Belgian Blue cows. Bacteriology was performed on cotton swab sampled from the visceral and parietal peritoneum of each cow during the CS. Most of samples showed a negative culture (55/76; 72.37%), 19/76 (25%) were positive (p < 0.0001) and two samples were contaminated. In total, 32 isolates belonging to 18 species were identified. Most of them are aerobic (17/18; 94.44%) and half of them were gram-negative (G-). The most encountered bacteria were Acinetobacter sp. (6/32; 18.75%), Pseudomonas sp. (4/32; 12.5%), Aerococcus viridans (4/32; 12.5%), Psychrobacter sp. (3/32; 9.37%), and Escherichia coli (2/32; 6.25%). Among the identified isolates, 31/32 (96.87%) were aerobic and 1/32 (3.12%) was anaerobic (p = 0.0001). Furthermore, 20/32 (62.50%) strains were G− while 12/32 (37.5%) were gram-positive (G+) (p = 0.012). In fact, most of cultured strains were aerobic G− (20/32), 11/32 were aerobic G+ and 1/32 is anaerobic G+ (p < 0.0001). In conclusion, most of samples showed a negative bacteriology; however, aerobic G− strains were the most identified in positive swabs. Therefore, preoperative antibiotics should be aimed against these bacteria.

The purpose of this work was to study the effects of substitution of fishmeal by housefly larvae at different rates and different physical states in the diet of local chickens. Five diets consisted of LFD, 25DL, 50DL, 25FL and 50FL, respectively, larval-free, 25%-dried-larvae, 50%-dried-larvae, 25%-fresh-larvae and 50%-fresh-larvae diet, in which 0, 25 and 50% of fishmeal was replaced by dried and fresh larvae, was formulated. A total of 165 local chickens of three weeks old, divided into 15 boxes in batches of 11 animals were raised. The experiment consists of three replications of five treatments. At 14 weeks of age, sixty chickens were slaughtered. Butchery skills and sensory characteristics were evaluated. Thus, a small variation of the ultimate pH from 5.63 to 5.55 between the different types of meat, and a carcass yield around 66%, was recorded. Any effects of substitution rate and physical state of housefly larvae on growth performance was not observed. Feet and proventriculus percentages increased in chickens fed 25% substitution. Liver and spleen percentage, and redder breast meat, increased in chicken fed dried larvae. Yellowness of the breast, thigh-and-drumstick meat and juiciness increased with 50% substitution. There is need of an investigation for liver and spleen enlargement and housefly larvae containing pigments. Thus, housefly larvae up to 50% substitution can be a suitable alternative to fishmeal in local chicken diets.

Ultrasonographic measurements of the caudal vena cava (CVC) and aorta (Ao) are known as reliable tools to assess intravascular volume status in humans. The aim of this study was to evaluate the feasibility of obtaining ultrasonographical measurements of CVC and Ao in two different views, assess intra- and interobserver variability, and study the effect of sex, age, body weight, and breed on measurements in healthy calves. The diameter and area of CVC and Ao were measured by a single investigator in two anatomic sites (subxiphoid and paralumbar window) in 48 calves aged less than 60 days and then repeated 2.5 months after the first assessment. For intra- and interobserver variability assessment, CVC and Ao measurements were repeated by three observers on five randomly selected calves. CVC and Ao measurements were easily obtained in PV and more difficult to obtain in SV. CVC and Ao area in PV showed high repeatability and reproducibility. A positive correlation was highlighted between age and CVC and Ao measurements in both sites. In conclusion, CVC size assessment by point of care ultrasound can be easily performed at a paralumbar site in calves under 4 months of age and could be used to assess intravascular volume status.

This study aimed to describe the inflammation, hydro-electrolyte and acid-base imbalances caused by generalised peritonitis (GP) and parietal fibrinous peritonitis (PFP) after caesarean section. After clinical examination, blood was sampled from 11 cows with PFP, 30 with GP and 14 healthy cows. Serum and plasma refractometry and glutaraldehyde tests were used to evaluate the inflammation level, while hydro-electrolytes and acid-base parameters were assessed using an EPOC® device. In addition to clinical signs of dehydration (>10%), blood analysis showed a high fibrinogen concentration (PFP: 8.64 ± 8.82 g/L; GP: 7.83 ± 2.45 g/L) and fast glutaraldehyde coagulation (<3 min) indicative of severe inflammation in both diseases compared to the control group (p < 0.05). Moreover, a severe decrease in electrolytes concentration (Na+: 126.93 ± 5.79 mmol/L; K+: 3.7 ± 1.3 mmol/L; Ca++: 0.89 ± 0.12 mmol/L; Cl−: 82.38 ± 6.45 mmol/L) and a significant increase in bicarbonate (30.87 ± 8.16 mmol/L), base excess (5.71 ± 7.42 mmol/l), L-lactate (8.1 ± 4.85 mmol/L) and creatinine (3.53 ± 2.30 mg/dL) were observed in cows with GP compared to the control group (p < 0.05). In contrast, few major perturbations were noticed in PFP, where only K+ (3.64 ± 0.25 mmol/L) and Ca++ (1.06 ± 0.09 mmol/L) were significantly modified (p < 0.05). In conclusion, a high dehydration and severe inflammation are induced by PFP and GP. Nevertheless, GP causes more electrolytes and acid-base disturbances than PFP.

Feeding chicken with black soldier fly larvae (BSF) may influence their rates of growth via effects on the composition of their gut microbiota. To verify this hypothesis, we aim to evaluate a probabilistic structural equation model because it can unravel the complex web of relationships that exist between the bacteria involved in digestion and evaluate whether these influence bird growth. We followed 90 chickens fed diets supplemented with 0%, 5% or 10% BSF and measured the strength of the relationship between their weight and the relative abundance of bacteria (OTU) present in their cecum or cloaca at 16, 28, 39, 67 or 73 days of age, while adjusting for potential confounding effects of their age and sex. Results showed that OTUs (62 genera) could be combined into ten latent constructs with distinctive metabolic attributes. Links were discovered between these constructs that suggest nutritional relationships. Age directly influenced weights and microbiotal composition, and three constructs indirectly influenced weights via their dependencies on age. The proposed methodology was able to simplify dependencies among OTUs into knowledgeable constructs and to highlight links potentially important to understand the role of insect feed and of microbiota in chicken growth.

Previous research has revealed the gut microbiota profile of several primate species, as well as the impact of a variety of anthropogenic factors, such as tourist food supply, on these bacterial communities. However, there is no information on the gut microbiota of the endangered wild Barbary macaque ( Macaca sylvanus ). The present study is the first to characterize the faecal microbiota of this species, as well as to investigate the impact of tourist food provisioning on it. A total of 12 faecal samples were collected in two groups of M. sylvanus in the region of Bejaia in Algeria. The first group-a tourist-provisioned one-was located in the tourist area of the Gouraya National Park and the second group-a wild-feeding one-was located in the proximity of the village of Mezouara in the forest of Akfadou. After DNA extraction, the faecal microbiota composition was analysed using 16S rDNA sequencing. Statistical tests were performed to compare alpha diversity and beta diversity between the two groups. Non-metric multidimensional scaling analysis (NMDS) was applied to visualize biodiversity between groups. Behaviour monitoring was also conducted to assess the time allocated to the consumption of anthropogenic food by the tourist-provisioned group. Our results revealed the presence of 209 bacterial genera from 17 phyla in the faecal microbiota of Barbary macaques. Firmicutes was the most abundant bacterial phylum, followed by Bacteroidetes and Verrucomicrobia. On the other hand, the comparison between the faecal microbiota of the two study groups showed that tourism activity was associated with a significant change on the faecal microbiota of M.sylvanus , probably due to diet alteration (with 60% of feeding time allocated to the consumption of anthropogenic food). The potentially low-fibre diet at the tourist site adversely influenced the proliferation of bacterial genera found in abundance in the wild group such as Ruminococcaceae . Such an alteration of the faecal microbiota can have negative impacts on the health status of these animals by increasing the risk of obesity and illness and calls for special management measures to reduce the provisioning rate in tourist areas.

The aim of this study was to identify the species and antimicrobial susceptibility of bacteria involved in parietal fibrinous peritonitis (PFP). We studied 156 peritoneal fluid samples from cows presenting PFP after caesarean section. Bacteria were cultured in selective media and their antimicrobial susceptibility was tested by disk diffusion assay. Bacteria were isolated in the majority (129/156; 83%) of samples. The majority (82/129; 63%) of positive samples contained one dominant species, while two or more species were cultured in 47/129 (36%) samples. Trueperella pyogenes ( T. Pyogenes) (107 strains) was the most identified species, followed by Escherichia coli ( E. coli ) (38 strains), Proteus mirabilis ( P. mirabilis ) (6 strains), and Clostridium perfringens ( C. perfringens ) (6 strains). Several other species were sporadically identified. Antimicrobial susceptibility was tested in 59/185 strains, predominantly E. coli (38 strains) and P. mirabilis (6 strains). Antibiotic resistance, including resistance to molecules of critical importance, was commonly observed; strains were classified as weakly drug resistant (22/59; 37%), multidrug resistant (24/59; 41%), extensively drug resistant (12/59; 20%), or pan-drug resistant (1/59; 2%). In conclusion, extensive antibiotic resistance in the isolated germs might contribute to treatment failure. Ideally, antimicrobial therapy of PFP should be based upon bacterial culture and susceptibility testing.

In order to improve the efficacy of penicillin injection during caesarean section, we aimed to identify the optimal timing of its preoperative administration. A study was conducted in 12 adult, non-pregnant Belgian Blue cows. To evaluate the plasma penicillin concentrations, blood samples were taken from the jugular vein at -5, 15, 30, 45, 60, 120, 240, 480 min relative to the intramuscular (IM) injection of 21,000 IU/kg of body weight of penicillin G. Results showed that plasma concentrations at 15 min after IM injection (668.3 ± 73.7 ng/mL) largely exceeded the minimal inhibitory concentration (MIC) of penicillin-sensitive bacteria (MIC < 125 ng/mL). With increasing time, plasma concentrations continued to rise, attaining an increasing proportion of moderately sensitive bacteria (250 ng/mL > MIC < 2000 ng/mL). The maximal concentration was reached between 1 and 4 h (average: 1.495.1 ± 181.7 ng/mL) after IM injection in the majority of cows, and decreased non-significantly to 1002.1 ± 93.2 ng/mL at 8 h. In conclusion, plasma penicillin concentrations at 15 min after an IM injection inhibit penicillin-sensitive bacteria. However, in order to obtain the maximal protective effect of the antibiotherapy, surgery should be started at 1 to 2 h after IM penicillin injection.

The aim of this study was to identify the pathogens potentially involved in parietal fibrinous peritonitis (PFP). PFP is a complication of laparotomy in cattle, characterized by an accumulation of exudate inside a fibrinous capsule. We have studied 72 cases of PFP in Belgian blue cows, confirmed by a standard diagnostic protocol. Blood was collected to evaluate the presence of antibodies for Mycoplasma bovis (M. bovis) , Coxiella burnetii (C. burnetii) and Bovine Herpesvirus 4 (BoHV4 ) by enzyme-linked immunosorbent assays. Peritoneal exudate was obtained from the PFP cavity to perform bacteriological culture, and to identify the DNA of M . bovis , C . burnetii and BoHV4 using real time polymerase chain reaction (qPCR). Bacteriological culture was positive in most peritoneal samples (59/72); Trueperella pyogenes ( T. pyogenes ) (51/72) and Escherichia coli ( E. coli ) (20/72) were the most frequently identified. For BoHV4 , the majority of cows showed positive serology and qPCR (56/72 and 49/72, respectively). Contrariwise, M. bovis (17/72 and 6/72, respectively) and C. burnetii (15/72 and 6/72, respectively) were less frequently detected ( p < 0.0001). Our study proves that PFP can no longer be qualified as a sterile inflammation. Moreover, we herein describe the first identification of BoHV4 and C. burnetii in cows affected by PFP.

Usutu virus (USUV) is a mosquito-borne flavivirus, closely related to the West Nile virus (WNV). Similar to WNV, USUV may cause infections in humans, with occasional, but sometimes severe, neurological complications. Further, USUV can be highly pathogenic in wild and captive birds and its circulation in Europe has given rise to substantial avian death. Adequate study models of this virus are still lacking but are critically needed to understand its pathogenesis and virulence spectrum. The chicken embryo is a low-cost, easy-to-manipulate and ethically acceptable model that closely reflects mammalian fetal development and allows immune response investigations, drug screening, and high-throughput virus production for vaccine development. While former studies suggested that this model was refractory to USUV infection, we unexpectedly found that high doses of four phylogenetically distinct USUV strains caused embryonic lethality. By employing immunohistochemistry and quantitative reverse transcriptase-polymerase chain reaction, we demonstrated that USUV was widely distributed in embryonic tissues, including the brain, retina, and feather follicles. We then successfully developed a primary cell line from the chorioallantoic membrane that was permissive to the virus without the need for viral adaptation. We believe the future use of these models would foster a significant understanding of USUV-induced neuropathogenesis and immune response and allow the future development of drugs and vaccines against USUV.