Bilateral nocardial endophthalmitis in a prothonotary warbler (Protonotaria citrea)

Doxycycline Hydrochloride Regulates Cytoskeletal Rearrangement and Epithelial-To-Mesenchymal Transition in Malignant Rhabdoid Tumour of the Kidney

Objective. As a highly malignant tumour, malignant rhabdoid tumours of the kidney (MRTK) are prone to metastasis and invasion, while tumour metastasis and invasion are inseparable from matrix metalloproteinases (MMPs) and epithelial-mesenchymal transformation (EMT). Moreover, the key to EMT is remodelling of the cytoskeleton. Therefore, our study is aimed at investigating whether doxycycline hydrochloride (DCH), an inhibitor of MMPs, could reverse EMT in MRTK to exert an antitumour effect by regulating MMPs and the cytoskeleton. Methods. The existence of EMT in MRTK cells was verified by bioinformatics analysis, immunofluorescence, and western blotting (WB). In vitro, the proliferation, migration, and invasion abilities of G401 cells were examined by Cell Counting Kit-8 (CCK-8), scratch, and Transwell assays, respectively. The effect of DCH on tumour growth in tumour-bearing mice was explored in in vivo experiments, and the expression of MMP2 and MMP9 and EMT correlation indexes was measured by immunofluorescence and WB, and the changes in cytoskeletal F-actin and β-tubulin were measured by fluorescence. Results. The altered extracellular matrix (ECM) composition, EMT, and high expression of MMP2 and MMP9 existed in MRTK. DCH inhibited the proliferation, migration, and invasion of G401 cells in vitro. In vivo, DCH inhibited tumour growth in mice, downregulated the expression of MMP2 and MMP9, and partially reversed EMT. Alternatively, DCH resulted in cytoskeletal rearrangements of G401 cells. Conclusions. DCH, as an MMP inhibitor, is used for the first time in MRTK research, showing good antitumour effects by reversing EMT and potentially providing new therapeutic measures for MRTK treatment.

First case report of fatal Nocardia nova infection in yellow-bibbed lory (Lorius chlorocercus) identified by multilocus sequencing

Background

Nocardiosis is often a multi-systemic disease in humans and other mammals. Nocardiosis in birds is uncommon. Laboratory identification of Nocardia to the species level is difficult by traditional phenotypic methods based on biochemical reactions and hydrolysis tests, and is most accurately performed by sequencing multiple gene targets.

Case presentation

We report the first case of fatal Nocardia nova infection in a yellow-bibbed lory nestling in an oceanarium diagnosed by multilocus sequencing. Necropsy examination showed effacement of normal sternal musculature with yellowish, firm aberrant material, and diffuse infiltration of the lungs with nodular, tan to yellow foci. Histologically, severe granulomatous inflammation with marked necrosis was observed in the lung, spleen and sternal musculature. Fine, sometimes Gram-positive, 0.5–1 μm wide, branching and beaded filamentous organisms were visible within the lesions. They were acid-fast on Fite-Faraco stain. Tissue samples obtained from the sternum, liver, right lung and right kidney recovered Nocardia species. Sequencing of four gene loci and phylogenetic analysis of concatenated (gyrB-16S-secA1-hsp65) sequences revealed that the isolate was N. nova.

Conclusions

We report the first case of N. nova infection in yellow-bibbed lorry (Lorius chlorocercus). The present case is the first one of which the species identity of the isolate was determined by multilocus sequencing. Molecular diagnosis is important for identifying the Nocardia to species level and understanding the epidemiology of nocardiosis in birds.

Incidence of hydrological, chemical, and physical constraints on bacterial pathogens, Nocardia cells, and fecal indicator bacteria trapped in an urban stormwater detention basin in Chassieu, France

The nature and fate of urban contaminants washed by stormwater events and accumulating in a detention basin (DB) were investigated. Relations between bacterial and chemical contaminants of trapped urban sediments, and field parameters were analyzed. Fecal indicators and some pathogens known to be environmentally transmitted (Nocardia, Pseudomonas aeruginosa, and Aeromonas caviae) were tracked, and their persistence investigated. Six sampling campaigns were carried out over 3 years, using five sites including a settling chamber (SC). Aerosolized bacteria at these sites were also monitored. Deposits in the basin were made of fine particles and their content in chemical pollutants was found highly variable. High polycyclic aromatic hydrocarbon (PAH) contents were measured but only three pesticides, over 22, were detected. Deposits were significantly contaminated by fecal indicator bacteria (FIB), P. aeruginosa, A. caviae, and by Nocardia. Only A. caviae showed significant numbers in aerosolized particles recovered over the detention basin. Nocardia spp. cells heavily contaminated the SC. The efficacy of the detention basin at reducing bacterial counts per rain event and over time were estimated. A slight drop in the counts was monitored for fecal indicators but not for the other bacterial groups. Hydrodynamic parameters had a strong impact on the distribution and features of the deposits. Multiple factors impacted the fate of FIB, P. aeruginosa, A. caviae, and Nocardia cells, but in a group dependent manner. Nocardia counts were found positively correlated with volatile organic matter. FIB appeared highly efficient colonizers of the DB.