Search Results

Now showing 1 - 3 of 3
Loading...
Thumbnail Image
Item

Shared MRSA Strains among Nepalese Rhesus macaques (Macaca mulatta), their Environment and Hospitalized Patients

2019, Roberts, Marilyn C., Joshi, Prabhu Raj, Monecke, Stefan, Ehricht, Ralf, Müller, Elke, Gawlik, Darius, Paudel, Saroj, Acharya, Mahesh, Bhattarai, Sankalpa, Pokharel, Sujana, Tuladhar, Reshma, Chalise, Mukesh K., Kyes, Randall C.

This study looked at 227 saliva samples from Rhesus macaques (Macaca mulatta) and 218 samples from the surrounding environments. From these samples, MRSA isolates were collected from Rhesus saliva samples (n = 13) and environmental samples (n = 19) near temple areas in Kathmandu, Nepal. For comparison, selected MRSA isolates (n = 5) were obtained from patients with wound infections from a Kathmandu hospital. All isolates were characterized using Abbott StaphyType® DNA microarrays. Eighteen isolates (62%) from monkeys (n = 4; 31%) and environmental samples (n = 14; 74%), were CC22-MRSA-IV. Most (n = 16) of them carried both, the PVL locus and toxic shock toxin gene (tst1), an unusual combination which is the same as in previously characterized strain from Nepalese macaques and pigs. The five human isolates also belonged to that strain type. Eight monkey MRSA isolates were CC361-MRSA-IV. One MRSA from a monkey and one from an environmental sample, were CC88-MRSA-V. Other environmental MRSA included one each, CC121-MRSA-VT, and CC772 -MRSA-V. Two were CC779-MRSA-VT, potentially a novel clone. All MRSA carried the blaZ gene. The aacA–aphD, dfrA, and erm (C) genes were very common in isolates from all sources. One macaque MRSA carried the resistance genes aphA3 and sat, neither previously identified in primate MRSA isolates. This current study suggests that humans could be a potential source of the MRSA in the macaques/environment and transmission may be linked to humans feeding the primates and/or living in close proximity to each other.This study looked at 227 saliva samples from Rhesus macaques (Macaca mulatta) and 218 samples from the surrounding environments. From these samples, MRSA isolates were collected from Rhesus saliva samples (n = 13) and environmental samples (n = 19) near temple areas in Kathmandu, Nepal. For comparison, selected MRSA isolates (n = 5) were obtained from patients with wound infections from a Kathmandu hospital. All isolates were characterized using Abbott StaphyType® DNA microarrays. Eighteen isolates (62%) from monkeys (n = 4; 31%) and environmental samples (n = 14; 74%), were CC22-MRSA-IV. Most (n = 16) of them carried both, the PVL locus and toxic shock toxin gene (tst1), an unusual combination which is the same as in previously characterized strain from Nepalese macaques and pigs. The five human isolates also belonged to that strain type. Eight monkey MRSA isolates were CC361-MRSA-IV. One MRSA from a monkey and one from an environmental sample, were CC88-MRSA-V. Other environmental MRSA included one each, CC121-MRSA-VT, and CC772 -MRSA-V. Two were CC779-MRSA-VT, potentially a novel clone. All MRSA carried the blaZ gene. The aacA–aphD, dfrA, and erm (C) genes were very common in isolates from all sources. One macaque MRSA carried the resistance genes aphA3 and sat, neither previously identified in primate MRSA isolates. This current study suggests that humans could be a potential source of the MRSA in the macaques/environment and transmission may be linked to humans feeding the primates and/or living in close proximity to each other.

Loading...
Thumbnail Image
Item

Vinculin binding angle in podosomes revealed by high resolution microscopy

2014, Walde, M., Monypenny, J., Heintzmann, R., Jones, G.E., Cox, S.

Podosomes are highly dynamic actin-rich adhesive structures formed predominantly by cells of the monocytic lineage, which degrade the extracellular matrix. They consist of a core of F-actin and actin-regulating proteins, surrounded by a ring of adhesion-associated proteins such as vinculin. We have characterised the structure of podosomes in macrophages, particularly the structure of the ring, using three super-resolution fluorescence microscopy techniques: stimulated emission depletion microscopy, structured illumination microscopy and localisation microscopy. Rather than being round, as previously assumed, we found the vinculin ring to be created from relatively straight strands of vinculin, resulting in a distinctly polygonal shape. The strands bind preferentially at angles between 116° and 135°. Furthermore, adjacent vinculin strands are observed nucleating at the corners of the podosomes, suggesting a mechanism for podosome growth.

Loading...
Thumbnail Image
Item

Object detection networks and augmented reality for cellular detection in fluorescence microscopy

2020, Waithe, Dominic, Brown, Jill M., Reglinski, Katharina, Diez-Sevilla, Isabel, Roberts, David, Eggeling, Christian

Object detection networks are high-performance algorithms famously applied to the task of identifying and localizing objects in photography images. We demonstrate their application for the classification and localization of cells in fluorescence microscopy by benchmarking four leading object detection algorithms across multiple challenging 2D microscopy datasets. Furthermore we develop and demonstrate an algorithm that can localize and image cells in 3D, in close to real time, at the microscope using widely available and inexpensive hardware. Furthermore, we exploit the fast processing of these networks and develop a simple and effective augmented reality (AR) system for fluorescence microscopy systems using a display screen and back-projection onto the eyepiece. We show that it is possible to achieve very high classification accuracy using datasets with as few as 26 images present. Using our approach, it is possible for relatively nonskilled users to automate detection of cell classes with a variety of appearances and enable new avenues for automation of fluorescence microscopy acquisition pipelines. © 2020 Waithe et al.