Chromosome geometry and intraspecific genetic polymorphism in Gram-positive bacteria revealed by pulsed-field gel electrophoresis (minireview)

1998 ◽  
Vol 19 (4) ◽  
pp. 582-588 ◽  
Author(s):  
Pierre Leblond ◽  
Bernard Decaris
2019 ◽  
Vol 24 (3) ◽  
pp. 129-133
Author(s):  
Max R. Schroeder ◽  
Vladimir Loparev

Introduction: Heat stabilization treatment preserves the in vivo state of biological samples by rapidly inactivating enzymes that cause degradation of proteins and nucleic acids. Historically, proteomics studies used this technique as an alternative to chemical fixation. More recently, microbiologists discovered that heat stabilization treatment rapidly inactivates pathogens present in tissue samples and preserves deoxyribonucleic acid (DNA) in the tissue. However, these recent studies did not investigate the inactivation of high-density bacterial suspensions and the quality of bacterial DNA. Methods and Results: High-density suspensions of Escherichia coli (>109 cfu/mL) were completely inactivated by heat stabilization treatment using the Denator Stabilizor T1 instrument at 72°C and 95°C for 45 seconds. Using the heat stabilization instrument, a panel of 30 species, 20 Gram-negative and 10 non-endospore-forming Gram-positive species, were fully inactivated by treatment (95°C for 45 seconds). DNA was isolated from bacterial suspensions of Gram-negative bacteria, including E. albertii, E. coli, Shigella dysenteriae, and S. flexneri, following inactivation via heat stabilization treatment and without treatment. DNA isolated following heat stabilization treatment was fully compatible with all downstream molecular applications tested, including next-generation sequencing, pulsed-field gel electrophoresis, multiplex polymerase chain reaction (PCR), and real-time PCR. Conclusions and Discussion: Heat stabilization treatment of Gram-negative and non-endospore-forming Gram-positive pathogens completely inactivates high-density bacterial suspensions. This treatment is compatible with downstream DNA molecular assays, including next-generation sequencing, pulsed-field gel electrophoresis, and PCR. Inactivation by heat stabilization is a rapid process that may increase safety by decreasing risks for laboratory-associated infections and risks associated with transportation of infectious materials.


1998 ◽  
Vol 36 (10) ◽  
pp. 3081-3084 ◽  
Author(s):  
Junichi Matsuda ◽  
Yoichi Hirakata ◽  
Fumiaki Iori ◽  
Chikako Mochida ◽  
Yumi Ozaki ◽  
...  

A total of 148 isolates from 55 bacteremic patients were examined by pulsed-field gel electrophoresis. Genetically different nonblood strains were isolated from 13.9% of patients with bacteremia caused by gram-positive cocci and 42.1% with Pseudomonas aeruginosabacteremia, indicating that antibiograms of a single nonblood P. aeruginosa isolate are not always informative for treatment of bacteremia.


2021 ◽  
Vol 13 (3) ◽  
pp. 602-610
Author(s):  
Eugene Y. H. Yeung ◽  
Ivan Gorn

Pulsed-field gel electrophoresis (PFGE) has historically been considered the gold standard in fingerprinting bacterial strains in epidemiological studies and outbreak investigations; little is known regarding its use in individual clinical cases. The current study detailed two clinical cases in which PFGE helped to determine the source of their methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Patient A was found to have MRSA bacteremia after trauma in her pelvic area. MRSA was also found in her groin but not in her nostril and rectum. PFGE was performed that showed variable bands of her MRSA isolates from blood and groin, suggestive of different strains of MRSA. Her MRSA bacteremia was determined to be unrelated to her pelvic trauma. Patient B was found to have MRSA bacteremia after colonoscopy. MRSA was also found in his nostril and rectum. PFGE was performed that showed variable bands of his MRSA isolates from blood and rectum but identical bands of MRSA isolates from his blood and nostril. His MRSA bacteremia was determined to be unrelated to his colonoscopy procedure. The current study demonstrates the use of PFGE to rule out the source of bacteremia in individual clinical cases.


2005 ◽  
Vol 71 (7) ◽  
pp. 3674-3681 ◽  
Author(s):  
S. Thisted Lambertz ◽  
M.-L. Danielsson-Tham

ABSTRACT Approximately 550 to 600 yersiniosis patients are reported annually in Sweden. Although pigs are thought to be the main reservoir of food-borne pathogenic Yersinia enterocolitica, the role of pork meat as a vehicle for transmission to humans is still unclear. Pork meat collected from refrigerators and local shops frequented by yersiniosis patients (n = 48) were examined for the presence of pathogenic Yersinia spp. A combined culture and PCR method was used for detection, and a multiplex PCR was developed and evaluated as a tool for efficient identification of pathogenic food and patient isolates. The results obtained with the multiplex PCR were compared to phenotypic test results and confirmed by pulsed-field gel electrophoresis (PFGE). In all, 118 pork products (91 raw and 27 ready-to-eat) were collected. Pathogenic Yersinia spp. were detected by PCR in 10% (9 of 91) of the raw pork samples (loin of pork, fillet of pork, pork chop, ham, and minced meat) but in none of the ready-to-eat products. Isolates of Y. enterocolitica bioserotype 4/O:3 were recovered from six of the PCR-positive raw pork samples; all harbored the virulence plasmid. All isolates were recovered from food collected in shops and, thus, none were from the patients' home. When subjected to PFGE, the six isolates displayed four different NotI profiles. The same four NotI profiles were also present among isolates recovered from the yersiniosis patients. The application of a multiplex PCR was shown to be an efficient tool for identification of pathogenic Y. enterocolitica isolates in naturally contaminated raw pork.


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