Canine pyoderma: mecA persists autogenous bacterin formulation from meticillin-resistant Staphylococcus pseudintermedius (MRSP) and S. aureus (MRSA)

2021 ◽  
Vol 49 (06) ◽  
pp. 437-440
Author(s):  
Anette Loeffler ◽  
Claire Scott ◽  
Siân-Marie Frosini

Abstract Objective Autogenous Staphylococcus pseudintermedius bacterins can reduce prescribing of antimicrobials in the management of canine recurrent pyoderma. However, increasing prevalence of meticillin-resistant, mecA-positive S. pseudintermedius (MRSP) raises concern over dispersal of mecA through bacterin therapy. We investigated the presence and integrity of mecA in bacterin formulations after manufacturing. Material and methods Twenty clinical isolates (12 MRSP, 7 MR-S. aureus, 1 meticillin-susceptible SP) were investigated. Pellets from overnight growth were washed 3 times with 0.5 % phenol saline, followed by addition of 0.1 ml 10 % formal-saline to 10 ml phenol-saline. Sterility was confirmed, and DNA extracted using both a standard genomic extraction kit and one recommended for formalin-fixed tissue samples (FFPE). The presence of mecA was determined after PCR and its integrity examined in 5 randomly selected samples after sequencing. Results In all bacterins from meticillin-resistant isolates, mecA was detected following FFPE extraction; products aligned fully to a reported mecA sequence. After standard DNA extraction, mecA was seen in 16/19 samples. Conclusion Persistence of mecA in MRSP bacterins suggests that dispersal of this important resistance mediator through therapy may be possible. While the ability of skin bacteria to uptake naked DNA remains unclear, it seems prudent to only formulate autogenous bacterins from mecA-negative S. pseudintermedius to avoid unnecessary spread of mecA.

2014 ◽  
Author(s):  
Sarah Munchel ◽  
Yen Hoang ◽  
Yue Zhao ◽  
Joseph Cottrell ◽  
Brandy Klotzle ◽  
...  

1998 ◽  
Vol 35 (2) ◽  
pp. 153-156 ◽  
Author(s):  
M. Boye ◽  
T. K. Jensen ◽  
K. Møller ◽  
T. D. Leser ◽  
S. E. Jorsal

Fluorescent in situ hybridization targeting 16S ribosomal RNA was used for specific detection of the obligate intracellular bacterium Lawsonia intracellularis in enterocytes from pigs affected by proliferative enteropathy. A specific oligonucleotide probe was designed and the specificity of the probe was determined by simultaneous comparison with indirect immunofluorescence assay for detection of L. intracellularis in formalin-fixed tissue samples from 15 pigs affected by porcine proliferative enteropathy. We used 10 tissue samples from pigs without proliferative mucosal changes as negative controls. The results showed that the oligonucleotide probe is specific for L. intracellularis and that fluorescent in situ hybridization targeting ribosomal RNA is a suitable and fast method for specific detection and histological recognition of L. intracellularis in formalin-fixed tissue.


Author(s):  
Steven C. Bauserman ◽  
Jonathan W. Valvano

Effect of formalin fixation on thermal conductivity of the biological tissues is presented. A self-heated thermistor probe was used to measure the tissue thermal conductivity. The thermal conductivity of muscle and fatty tissue samples was measured before the formalin fixation and then 27 hours after formalin fixation. The results indicate that the formalin fixation does not cause a significant change in the tissue thermal conductivity of muscle and fatty tissues. In the clinical setting, tissues removed surgically are often fixed in formalin for subsequent pathological analysis. These results suggest that, in terms of thermal properties, it is equally appropriate to perform in vitro studies in either fresh tissue or formalin-fixed tissue.


2004 ◽  
Vol 121 (6) ◽  
pp. 794-800 ◽  
Author(s):  
Batia Kaplan ◽  
Brian M. Martin ◽  
Avi Livneh ◽  
Mordechai Pras ◽  
Gloria R. Gallo

2005 ◽  
Vol 53 (10) ◽  
pp. 1189-1197 ◽  
Author(s):  
William J. Howat ◽  
Anthony Warford ◽  
Joanne N. Mitchell ◽  
Kay F. Clarke ◽  
Jen S. Conquer ◽  
...  

Tissue microarray (TMA) technology allows the miniaturization and characterization of multiple tissue samples on a single slide and commonly uses formalin-fixed paraffin-embedded (FFPE) tissue or acetone-fixed frozen tissue. The former provides good morphology but can compromise antigenicity, whereas the latter provides compromised morphology with good antigenicity. Here, we report the development of TMAs in glycol methacrylate resin, which combine the advantages of both methods in one embedding format. Freshly collected tissue fixed in -20C acetone or 10% neutral buffered formaldehyde were cored and arrayed into an intermediary medium of 2% agarose before infiltration of the agarose array with glycol methacrylate resin. Acetone-fixed resin TMA demonstrated improved morphology over acetone-fixed frozen TMA, with no loss of antigenicity. Staining for extracellular, cell surface, and nuclear antigens could be realized with monoclonal and polyclonal antibodies as well as with monomeric single-chain Fv preparations. In addition, when compared with FFPE TMA, formalin-fixed tissue in a resin TMA gave enhanced morphology and subcellular detail. Therefore, resin provides a universal format for the construction of TMAs, providing improved tissue morphology while retaining antigenicity, allows thin-section preparation, and could be used to replace preparation of frozen and FFPE TMAs for freshly collected tissue.


2010 ◽  
Vol 74 (3) ◽  
pp. 465-470 ◽  
Author(s):  
Ferran Palero ◽  
Sally Hall ◽  
Paul F. Clark ◽  
David Johnston ◽  
Jackie Mackenzie-Dodds ◽  
...  

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