A diagnostic PCR assay for the detection of an Australian epidemic strain of Pseudomonas aeruginosa

Background Chronic lung infection with the bacterium Pseudomonas aeruginosa is one of the hallmarks of cystic fibrosis (CF) and is associated with worsening lung function, increased hospitalisation and reduced life expectancy. A virulent clonal strain of P. aeruginosa (Australian epidemic strain I; AES-I) has been found to be widespread in CF patients in eastern Australia. Methods Suppression subtractive hybridization (SSH) was employed to identify genetic sequences that are present in the AES-I strain but absent from the sequenced reference strain PAO1. We used PCR to evaluate the distribution of several of the AES-I loci amongst a collection of 188 P. aeruginosa isolates which was comprised of 35 AES-I isolates (as determined by PFGE), 78 non-AES-I CF isolates including other epidemic CF strains as well as 69 P. aeruginosa isolates from other clinical and environmental sources. Results We have identified a unique AES-I genetic locus that is present in all 35 AES-I isolates tested and not present in any of the other 153 P. aeruginosa strains examined. We have used this unique AES-I locus to develop a diagnostic PCR and a real-time PCR assay to detect the presence of P. aeruginosa and AES-I in patient sputum samples

Surgical enucleation of unilateral mandibular radicular cysts in an 11-year-old Thoroughbred mare

An 11‐year‐old Thoroughbred broodmare was diagnosed with extensive radicular cysts that affected the left horizontal mandibular ramus. A left mandibular swelling was present clinically, and mandibular lesions appearing cystic in nature were identified with successive radiographic and ultrasonographic examinations. Surgical enucleation of the cysts was performed under a standing sedation protocol and the excised cystic structures submitted for histopathological analysis. Histological examination of the cystic structures confirmed a diagnosis of multiple radicular cysts.https://beva-onlinelibrary-wiley-com/journal/204232922020-06-01hj2020Companion Animal Clinical Studie

UV emission from lanthanide-doped upconversion nanoparticles in super-resolution microscopy: potential for cellular damage

Published: April 13, 2023Upconversion nanoparticles (UCNPs) co-doped with lanthanide ions have recently attracted significant attention as fluorescent probes for super-resolution microscopy (SRM). This is due to the advantages of UCNPs over other fluorescence probes, such as fluorescent proteins, owing to their unique optical properties, limited photobleaching, and sharp emissions. However, the concurrent emission of ultraviolet (UV) wavelength radiation by UCNPs and the potential for cell photodamage, which may limit useful live-cell analysis, have been overlooked. Here, UCNPs synthesized with eight commonly used combinations of Yb/Tm and Yb/Tm/Gd dopants were excited by either pulsed- or continuous-wave (CW) lasers to evaluate their UV emission. The ratio of emitted UV-A and UV-B was measured relative to blue emission at 475 nm, which is traditionally used for imaging during SRM. We demonstrate that most UCNP samples emit UV light and that the dopant concentration has a key role in generating UV emissions. In addition, the use of pulsed or CW lasers for excitation can lead to a large variation in the amount of UV emitted. This work highlights the importance of considering upconversion dopant composition and concentration, as well as analyzing the emission of synthesized UCNPs before their use to prevent unwanted cell photodamage during live-cell imaging by SRM. Moreover, it established a need to improve the visible light emission of UCNPs with respect to UV emission for SRM applications.Afshin Karami, Thomas J. de Prinse, Nigel A. Spooner, Stephen P. Kidd, Christopher J. Sumby, and Jingxiu B