The possibility that Dermanyssus gallinae, the poultry red mite, could act as a vector of infectious disease-causing pathogens has always intrigued researchers and worried commercial chicken farmers, as has its ubiquitous distribution. For decades, studies have been carried out which suggest that there is an association between a wide range of pathogens and D. gallinae, with the transmission of some of these pathogens mediated by D. gallinae as vector. The latter include the avian pathogenic Escherichia coli (APEC), Salmonella enterica serovars Enteritidis and Gallinarum and influenza virus. Several approaches have been adopted to investigate the relationship between D. gallinae and pathogens. In this comprehensive review, we critically describe available strategies and methods currently available for conducting trials, as well as outcomes, analyzing their possible strengths and weaknesses, with the aim to provide researchers with useful tools for correctly approach the study of the vectorial role of D. gallinae. Graphical Abstract
Mycotoxins are toxic secondary metabolites produced by fungal species that usually contaminate foods and feeds. Their lipophilic properties allow them to persist in the fat tissues of animals that ingest them, representing a risk for the consumers because of their toxicity and carcinogenicity. Apart from their toxicity to humans, there are species more susceptible to the mycotoxin actions, such as the avian ones. This report describes a case in a laying hen farm certified as antibiotic-free, where animals were fed with foodstuff with linseed added to obtain eggs enriched in omega-3 fat acids. In this case, the concurrent action of aflatoxin B1 and ochratoxin A caused a significant decrease in production and an increase in mortality. At pathologic examinations, the animals showed severe kidney degeneration along with liver lesions. The ovary and oviduct were hypoplastic, and evident signs of anemia were observed. Aflatoxin B1 and ochratoxin A were detected by HPLC in foodstuff with the addition of linseed and in organs. This case wants to drive attention to the importance of a careful check of the feedstuff to be used in poultry farms with a quality-oriented production, in order to avoid contaminations that can harm both animal welfare and public health.
Large numbers of wild animals are injured every year in road traffic accidents. Scant data are available for rescued wild carnivores, in particular for red foxes. Cases of foxes with head trauma were retrospectively considered for inclusion in this study. Clinical examination, modified Glasgow coma scale (MGCS), computed tomography (CT) examination, therapy, outcome, and post mortem findings of the brain were investigated. In all foxes, cranial vaults lesion occurred in single (67%) or multiple sites (33%). Midline shift and hydrocephalus were observed in this population. The mean survival was 290 (±176) days. In our study, we performed CT scans on average 260 days after fox rescue, and we speculate that persisting clinical signs could be attributed to TBI. In our study, only two foxes were alive at the time of writing. Other foxes were euthanized due to the severity of the clinical signs. CT scans help diagnose chronic lesions and their effect on prognostic judgment for animals released to wildlife environments.
Long-read sequencing (LRS), like Oxford Nanopore Technologies, is usually associated with higher error rates compared to previous generations. Factors affecting the assembly quality are the integrity of DNA, the flowcell efficiency, and, not least all, the raw data processing. Among LRS-intended de novo assemblers, Canu is highly flexible, with its dozens of adjustable parameters. Different Canu parameters were compared for assembling reads of Salmonellaenterica ser. Bovismorbificans (genome size of 4.8 Mbp) from three runs on MinION (N50 651, 805, and 5573). Two of them, with low quality and highly fragmented DNA, were not usable alone for assembly, while they were successfully assembled when combining the reads from all experiments. The best results were obtained by modifying Canu parameters related to the error correction, such as corErrorRate (exclusion of overlaps above a set error rate, set up at 0.40), corMhapSensitivity (the coarse sensitivity level, set to “high”), corMinCoverage (set to 0 to correct all reads, regardless the overlaps length), and corOutCoverage (corrects the longest reads up to the imposed coverage, set to 100). This setting produced two contigs corresponding to the complete sequences of the chromosome and a plasmid. The overall results highlight the importance of a tailored bioinformatic analysis.
The poultry red mite Dermanyssus gallinae is a hematophagous ectoparasite of layer hens. Infestations with poultry red mites pose an increasing threat to the egg production industry, causing serious problems to animal health and welfare, directly or indirectly as a vector of several infectious agents. In this study, we aimed to investigate common avian pathogens in mites. The mite samples were collected from 58 poultry farms in 7 regions accounting for more than 70 % of the national egg production in Algeria. The presence of 13 avian pathogens was detected using DNA and RNA samples from mites collected. Results revealed significant associations between PRM and potential pathogens such as Escherichia coli, Salmonella enterica, fowlpox virus, and gallid herpesvirus 1. Pathogen detection in Dermanyssus gallinae could serve as an early diagnostic or a risk analysis tool for infectious diseases in poultry farms, facilitating effective disease management strategies. Despite further research being necessary to address uncertainties, such a strategy could be used to enhance the integrated management of poultry health.