Systemic distribution of Staphylococcus aureus following intradermal footpad challenge of broilers

The composition of microbial aerosols, PM2.5, and PM10 in a duck house in Shandong province, China

Poultry-emitted air pollutants, including microbial aerosols and particulate matter, have raised concerns due to their potential negative effects on human health and the environment. High concentrations of microbial aerosols can also significantly affect duck production performance, leading to immunosuppression and increased disease susceptibility. We determined the concentrations, distributions, and biological components of the microbial aerosols and particulate matter in a duck house environment. The concentration ranges of the bacteria, fungi, Gram-negative bacteria, Escherichia coli, and endotoxin in the duck houses were 3.3 to 5.2 × 104 CFU/m3, 3.8 to 11.9 × 103 CFU/m3, 2.1 to 3.6 × 103 CFU/m3, 1.3 to 2.7 × 102 CFU/m3, and 0.65 to 2.2 × 103 EU/m3, respectively. We also found the endotoxin levels were higher than the standard that can cause pneumonia (2,000 EU/m3). The concentration ranges of the PM2.5 and PM10 samples were 1.1 to 1.6 × 102 μg/m3 and 1.2 to 1.9 × 102 μg/m3, respectively. At the phylum level, the top 5 bacteria identified in the PM2.5 fraction were Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes, and Fusobacteria, with Actinobacteria (50.55%) as the most abundant. At the genus level, 293 bacterial groups were identified. Actinobacteria (39.01%) was the most abundant phylum, followed by Firmicutes (5.44%) and Proteobacteria (4.56%). The bacterial distributions that differed between the PM2.5 and PM10 samples were Lactobacillales, Bacilli, Firmicutes, and Bacteroidetes; the fungi that differed were Microbotryomycetes, Sporidiobolales, Agaricomycetes, and Polyporates. Microbial allergens and pathogens were also identified. Corynebacterium had a relative abundance of more than 30% in the PM2.5 and PM10 distributions. Aspergillus was the main fungal allergen and opportunistic pathogen, with a relative abundance of 10%. In conclusion, our research supports that the microbial composition in the duck house environment poses a potential threat to the health of both the ducks and the duck house workers.

Staphylococcus aureus in veterinary medicine

Staphylococcus aureus is a major opportunistic pathogen in humans and one of the most important pathogenic Staphylococcus species in veterinary medicine. S. aureus is dangerous because of its deleterious effects on animal health and its potential for transmission from animals to humans and vice-versa. It thus has a huge impact on animal health and welfare and causes major economic losses in livestock production. Increasing attention is therefore being paid to both livestock and companion animals in terms of this pathogen. In this review, we summarise the current knowledge on the animal host adaptation of S. aureus. Different types of S. aureus infections in animals are also presented, with particular emphasis on mastitis in dairy herds, which is probably the costliest and therefore the best documented S. aureus infection seen in animals.

Delivery and Inhibition of Reporter Genes by Small Interfering RNAs in a Mouse Skin Model

RNA interference offers the potential of a novel therapeutic approach for treating skin disorders. To this end, we investigated delivery of nucleic acids, including a plasmid expressing the reporter gene luciferase, to mouse skin by intradermal injection into footpads using in vivo bioluminescence imaging over multiple time points. In order to evaluate the ability of RNA interference to inhibit skin gene expression, reporter gene constructs were co-injected with specific or non-specific siRNAs and the in vivo effects measured. Our results revealed that specific unmodified and modified siRNAs (but not nonspecific matched controls) strongly inhibit reporter gene expression in mice. These results indicate that small interfering RNA, delivered locally as RNA directly or expressed from viral or non-viral vectors, may be effective agents for treating skin disorders.

A possible relationship between bumblefoot responsive to potassium arsenite and micrococci in the blood of three birds of prey

Pododermatitis (bumblefoot) is a major health problem of falcons world-wide because healing processes in the talons are difficult and lengthy. A peregrine (Falco peregrinus), a merlin (Falco columbarius) and a saker falcon (Falco cherrug) with bumblefoot at different stages ranging from III to V, were all found to be carriers of micrococcus-like organisms in the blood and two of them were successfully treated with 0.5% potassium arsenite in low dosage given intravenously. A number of considerations are made on the immune dysfunction aspects of bumblefoot in birds of prey and on the emerging role of arsenic-based medicaments in the treatment of animal and human immune dysfunction syndromes.