Arne Jung

Knowledge about chickens’ immune response to infection with Enterococcus cecorum (EC) and prophylactic strategies is scarce. This study aimed to investigate the protective effect of an EC-specific hyperimmune serum after experimental challenge with homologous EC. A total of 284 one-day-old meat-type chickens were randomly assigned to three groups (non-inoculated (C), passively immunized with hyperimmune serum and EC-inoculated (EPI), and EC-inoculated (E)). At 1 and 2 days post-hatch (dph), the hyperimmune serum was subcutaneously administered to each chicken in group EPI. Oral inoculation with EC was carried out at 2 dph. Blood samples and cloacal swabs were collected at 7, 14, 21, 28, and 35 dph and necropsy was carried out at 42/43 dph. Extraintestinal colonization with EC was significantly decreased in group EPI compared to group E. Additionally, femoral head necrosis and spondylitis of the free thoracic vertebra were significantly decreased in group EPI compared to group E. Flow cytometric analysis revealed a significant increase in heterophils, monocytes, and the heterophil/lymphocyte ratio in the peripheral blood of bacteriological positive chickens. Although the parenteral application of a hyperimmune serum lacks practicability in meat-type chicken flocks, the results of this study encourage further research on vaccination of meat-type chicken breeder flocks.

Worldwide outbreaks make infections with pathogenic strains of Enterococcus cecorum (EC) one of the most important diseases in the broiler industry. Although research has increased knowledge about the pathogen, the transmission is not fully understood. Samples from different locations were collected from two broiler farms in Germany over a total of six production cycles. Samples were collected at days 1, 5, 10, 15, 21, 27, 34, 41 post-hatch and after cleaning and disinfection (C&D). A total of 1017 samples were collected from 25 different locations on the farms. Samples were analysed in the laboratory for EC by quantitative real-time PCR. Overall, 7.5% of the samples were positive. The probabilities for positive and negative samples did not differ between the farms. The number of findings differed significantly between the cycles. Compared to other samples, the chances of detecting EC in faecal samples were significantly higher. Most positive samples were found in the last week of the production periods, indicating an accumulation of EC in the barn environment. After C&D, positive PCR results were obtained in four out of 14 locations. A re-entrainment from contaminated environment seemed possible. However, one pooled faecal sample was positive one day post-hatch. The locations that showed positive results after C&D and the positive faecal sample one day post-hatch indicated the persistence of EC in broiler houses of clinically healthy flocks that could lead to potential horizontal transmission routes. The present study detected potential EC sources and may help to improve hygienic measures to avoid transmissions.Research Highlights: methodology is suitable to detect EC during production and after C&Dlocations were detected that may serve as a reservoir for ECcycles with fewer positive samples were observedcleaning and disinfection had a major impact on the detection of EC.

This study aimed to develop a method for standardized broth microdilution antimicrobial susceptibility testing (AST) of Avibacterium ( Av .) paragallinarum , the causative agent of infectious coryza in chickens. For this, a total of 83 Av. paragallinarum isolates and strains were collected from 15 countries. To select unrelated isolates for method validation steps, macrorestriction analyses were performed with 15 Av. paragallinarum . The visible growth of Av. paragallinarum was examined in six broth media and growth curves were compiled. In Veterinary Fastidious Medium and cation-adjusted Mueller-Hinton broth (CAMHB) + 1% chicken serum + 0.0025% NADH (CAMHB + CS + NADH), visible growth of all isolates was detected and both media allowed adequate bacterial growth. Due to the better readability of Av. paragallinarum growth in microtiter plates, CAMHB + CS + NADH was chosen for AST. Repetitions of MIC testing with five epidemiologically unrelated isolates using a panel of 24 antimicrobial agents resulted in high essential MIC agreements of 96%–100% after 48-h incubation at 35 ± 2°C. Hence, the remaining 78 Av. paragallinarum were tested and demonstrated easily readable MICs with the proposed method. Differences in MICs were detected between isolates from different continents, with isolates from Africa showing lower MICs compared to isolates from America and Europe, which more often showed elevated MICs of aminoglycosides, quinolones, tetracyclines, and/or trimethoprim/sulfamethoxazole. PCR analyses of isolates used for method development revealed that isolates with elevated MICs of tetracyclines harbored the tetracycline resistance gene tet (B) but none of the other tested resistance genes were detected. Therefore, whole-genome sequencing data from 62 Av. paragallinarum were analyzed and revealed the presence of sequences showing nucleotide sequence identity to the genes aph(6)-Id , aph(3″)-Ib , bla _TEM-1B , catA2, sul2 , tet (B), tet (H), and mcr- like. Overall, the proposed method using CAMHB + CS + NADH for susceptibility testing with 48-h incubation time at 35 ± 2°C in ambient air was shown to be suitable for Av. paragallinarum . Due to a variety of resistance genes detected, the development of clinical breakpoints is highly recommended. IMPORTANCE: Avibacterium paragallinarum is an important pathogen in veterinary medicine that causes infectious coryza in chickens. Since antibiotics are often used for treatment and resistance of the pathogen is known, targeted therapy should be given after resistance testing of the pathogen. Unfortunately, there is currently no accepted method in standards that allows susceptibility testing of this fastidious pathogen. Therefore, we have worked out a method that allows harmonized susceptibility testing of the pathogen. The method meets the requirements of the CLSI and could be used by diagnostic laboratories.

Increasing digitalization in animal farming, commonly addressed as Precision Livestock Farming (PLF), offers benefits in terms of productivity, sustainability, reduced labor and improved monitoring of animal welfare. However, the large amounts of collected data must be stored, processed and evaluated in a proper way. In practice, challenges of continuous and exact data collection can arise, e.g., from air pollutants like dust occluding cameras and sensors, degrading material, the ever-present commotion caused by animals, workers and machines, regularly required maintenance or weak signal transmission. In this study, we analyzed the quality of multi-source spatio-temporal data from a broiler house with 8100 birds over a period of 31 months collected by the Farmer Assistant System (FAS). This is a ceiling-suspended robot equipped with several sensors and cameras that continuously collect data while moving through the barn. The data analysis revealed numerous irregularities: missing values, outliers, repetitive measurements, systematic errors, and temporal and spatial inconsistencies. About 40–50% of all records collected with the early version of the FAS had to be sorted out. The newer version of FAS provided cleaner data, although still about 10–20% of the data had to be removed. Our study has shown that where sophisticated technological systems meet a challenging environment, a thorough and critical review of data completeness and quality is crucial to avoid misinterpretation. The pipeline developed here is designed to help developers and farmers detect failures in signal processing and localize the problem in the hardware components. Scientists, industrial developers and farmers should work more closely together to develop new PLF technologies to more easily advance digitization in agriculture.

Avibacterium paragallinarum (A. paragallinarum) is the etiological agent of infectious coryza (IC) in chickens and characterized by acute respiratory distress and severe drop in egg production. Vaccination is important in the control of IC outbreaks and the efficacy of vaccination is dependent on A. paragallinarum serovars included in the vaccine. Classical serotyping of A. paragallinarum is laborious and hampered by the poor availability of antigens and antisera. The hemagglutinin (HA), important in classical serotyping is encoded by the HMTp210 gene. HMTp210 gene analysis has shown to have potential as alternative for classical serotyping. The aim of the present study was to further investigate the potential of sequence analyses of nucleotides 1-∼1200 of region one of the HMTp210 gene, the HMTp210 hypervariable region and the concatenated sequences of both gene fragments. For this analysis 123 HMTp210 gene sequences (field isolates, A. paragallinarum serovar reference strains and vaccine strains) were included. Evaluation of serovar references and vaccine strains revealed a need for critical evaluation, especially within Page serovar B and C. Phylogenetic analysis of HMTp210 region 1 resulted in a separation of Page serovar A, B and C strains. Analysis of the HMTp210 HVR alone was not sufficient to discriminate all nine different Kume serovar references. The concatenated sequences of HMTp210 region 1 and HMTp210 HVR resulted in fourteen clusters with a high correlation with Page serovar and with the nine currently known Kume serovars and is therefore proposed as a novel genotyping method that could be used as an alternative for classical serotyping of A. paragallinarum.

Enterococcus cecorum(EC) is one of the most relevant bacterial pathogens in modern broiler chicken production from an economic and animal welfare perspective. Although EC pathogenesis is generally well described, predisposing factors are still unknown. This study aimed to understand the effect of heat stress on the caecal microbiota, intestinal integrity, and EC pathogenesis. A total of 373 1-day-old commercial broiler chicks were randomly assigned to four groups: (1) noninoculated, thermoneutral conditions (TN); (2) noninoculated, heat stress conditions (HS); (3) EC-inoculated, thermoneutral conditions (TN + EC); and (4) EC-inoculated, heat stress conditions (HS + EC). Birds were monitored daily for clinical signs. Necropsy of 20 broilers per group was performed at 7, 14, 21, and 42 days post-hatch (dph). A trend towards enhanced and more pronounced clinical disease was observed in the EC-inoculated, heat-stressed group. EC detection rates in extraintestinal tissues via culture were higher in the HS + EC group (~19%) than in the TN + EC group (~11%). Significantly more birds were colonized by EC at 7 dph in the HS + EC group (100%) than in the TN + EC group (65%,p < 0.05). The caecal microbiota in the two EC-inoculated groups was significantly more diverse than that in the TN group (p < 0.05) at 14 dph, which may indicate an effect of EC infection. An influence of heat stress on mRNA expression of tight junction proteins in the caecum was detected at 7 dph, where all six investigated tight junction proteins were expressed at significantly lower levels in the heat stressed groups compared to the thermoneutral groups. These observations suggest that heat stress may predispose broilers to EC-associated disease and increase the severity thereof. Furthermore, heat stress may impair intestinal integrity and promote EC translocation.

The Common Eider (Somateria mollissima) inhabits the entire northern hemisphere. In northern Europe, the flyway population reaches from the southern Wadden Sea to the northern Baltic coast. The European population is classified as endangered due to declines in Common Eider numbers across Europe since 1990. In this study, we assessed 121 carcasses of Common Eiders, captured incidentally in gillnets in the Western Baltic between 2017 and 2019. The most common findings were parasitic infections of the intestine by acanthocephalans in 95 animals, which correlated with enteritis in 50% of the cases. Parasites were identified as Profilicollis botulus in 25 selected animals. Additionally, oesophageal pustules, erosions, and ulcerations, presumably of traumatic origin, were frequently observed. Nephritis and hepatitis were frequent, but could not be attributed to specific causes. Lung oedema, fractures and subcutaneous haemorrhages likely resulted from entangling and drowning. Two Common Eiders had mycobacterial infections and in one of these, Mycobacterium avium subspecies (ssp.) avium was identified. This study gives an overview of morphological changes and infectious diseases from one location of the European flyway population. It contributes to future health studies on Common Eiders in the Baltic and Wadden Seas by providing baseline information to compare with other areas or circumstances.

Introduction Since 2002, pathogenic strains of Enterococcus (E.) cecorum (EC) have caused disease outbreaks, especially in broiler chickens (Devriese et al., 2002a; Wood et al., 2002). This infection leads to enterococcal spondylitis (ES) particularly