Methicillin-Resistant Staphylococcus aureus in Tertiary Care Institutions of the Canadian Prairies 1990-1992

1994 ◽  
Vol 15 (10) ◽  
pp. 646-651 ◽  
Author(s):  
J. Embil ◽  
K. Ramotar ◽  
L. Romance ◽  
M. Alfa ◽  
J. Conly ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Acute Care ◽  
Gel Electrophoresis ◽  
Tertiary Care ◽  
Pulsed Field Gel Electrophoresis ◽  
Teaching Hospitals ◽  
Polymorphism Analysis ◽  
Canadian Prairies ◽  
Pulsed Field ◽  
Care Teaching

AbstractObjective:To review experience with methicillin-resistant Staphylococcus aureus (MRSA) in tertiary acute-care teaching hospitals on the Canadian prairies.Design:Retrospective review for a 36-month period, 1990 through 1992.Setting:Five tertiary acute-care teaching hospitals in three Canadian prairie provinces.Methods:MRSA isolates and susceptibility were identified through the clinical microbiology laboratory at each institution. For each patient, data collected included duration of institutional residence prior to isolation, patient ethnic background, age, sex, and antimicrobial susceptibility. Epidemiologic typing of strains used restriction fragment length polymorphism analysis by pulsed-field gel electrophoresis.Results:Two hundred fifty-nine MRSA isolates were identified in 135 patients during the 36 months, with substantial institutional variation in number of isolates. No consistent increase in yearly numbers of isolates was apparent. Patients usually had MRSA identified at admission (62%); only one of five centers had the majority of isolates acquired nosocomially. Patients with MRSA present at admission were more frequently of aboriginal (First Nations) ethnicity (62% compared with 14% of nosocomial; P<0.001). Pulsed-field gel electrophoresis of 167 isolates from 135 patients revealed 46 different strains with little interprovincial or inter-institutional identity of strains.Conclusions:MRSA isolated in patients in tertiary care institutions in these three Canadian provinces usually is acquired prior to admission. A disproportionate number of isolates are identified in aboriginal Canadians. Epidemiologic typing was consistent with a polyclonal origin of MRSA in this geographic area.

scholarly journals Understanding the Local Epidemiology of Methicillin-Resistant Staphylococcus aureus by Pulsed-Field Gel Electrophoresis in an Indian Tertiary Care Centre

2021 ◽  
Author(s):  
Avinandan Saha ◽  
Priyanka Prasad ◽  
Gita Nataraj
Keyword(s):  
Staphylococcus Aureus ◽  
Infection Control ◽  
Gel Electrophoresis ◽  
Healthcare Workers ◽  
Tertiary Care ◽  
Pulsed Field Gel Electrophoresis ◽  
Methicillin Resistant ◽  
Pulsed Field ◽  
Hospital Infection Control ◽  
Prospective Longitudinal

Abstract Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of community and hospital-acquired infections (HAIs). In the year preceding this study, our laboratory reported an MRSA isolation rate of 2% from 50,549 specimens. Molecular typing of MRSA identifies sources of infection, transmission chains and informs infection control practices, and pulsed-field gel electrophoresis (PFGE) is the gold standard. This study was conducted to gain an understanding of the local molecular epidemiology of MRSA in our hospital using PFGE, to inform hospital infection control practices.Methods: This prospective longitudinal study was conducted in the microbiology laboratory of our 2,200-bed tertiary care teaching hospital in Mumbai, India.The antibiotic susceptibility profiles and pulsed-field profiles (PFPs) of 100 consecutive non-duplicate clinical isolates of MRSA were obtained. The PFPs were compared to check for relatedness of isolates. The distribution of various pulsotypes across disciplines and hospital locations was examined.Results: Clinical specimens accounted for 86 (86%) of the MRSA isolates, whilst 14 (14%) were from screening of healthcare workers. Maximum isolates, 68 (68%), were from surgical disciplines. Confirmed HAIs accounted for 25 (25%) MRSA isolates. Seventeen antibiotypes were obtained and there was no correlation between antibiotype and pulsotype. Totally 43 pulsotypes were identified, with most isolates, 40 (40%), belonging to pulsotype 1. Seven clusters were identified. Cluster I had maximum pulsotypes, 14, and 58 (58%) isolates. Isolates belonging to clusters I and II were found in all hospital locations. Relatedness was observed between isolates from HAIs and screening specimens, and between community and HAI isolates.Conclusions: PFGE typing revealed the disciplines at greatest risk from MRSA in our hospital. The commonality between MRSA isolated from HAIs and screening of healthcare workers, and between MRSA isolated from HAIs and from community-acquired infections highlighted the horizontal transmission of MRSA and the need to reinforce infection control measures to limit this.

scholarly journals Use of Pulsed-Field Gel Electrophoresis to Determine the Source of Methicillin-Resistant Staphylococcus aureus Bacteremia

2021 ◽  
Vol 13 (3) ◽  
pp. 602-610
Author(s):  
Eugene Y. H. Yeung ◽  
Ivan Gorn
Keyword(s):  
Staphylococcus Aureus ◽  
Gel Electrophoresis ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Epidemiological Studies ◽  
Pelvic Trauma ◽  
Pulsed Field Gel Electrophoresis ◽  
Bacterial Strains ◽  
Methicillin Resistant ◽  
Pulsed Field ◽  
Clinical Cases

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.

scholarly journals Assessment of Resolution and Intercenter Reproducibility of Results of Genotyping Staphylococcus aureus by Pulsed-Field Gel Electrophoresis of SmaI Macrorestriction Fragments: a Multicenter Study

1998 ◽  
Vol 36 (6) ◽  
pp. 1653-1659 ◽  
Author(s):  
Alex van Belkum ◽  
Willem van Leeuwen ◽  
Mary Elizabeth Kaufmann ◽  
Barry Cookson ◽  
Françoise Forey ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Pfge Type ◽  
Data Sets ◽  
Bacterial Typing ◽  
Technical Problems ◽  
Pulsed Field ◽  
Pattern Similarity ◽  
Percent Similarity

Twenty well-characterized isolates of methicillin-resistantStaphylococcus aureus were used to study the optimal resolution and interlaboratory reproducibility of pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments. Five identical isolates (one PFGE type), 5 isolates that produced related PFGE subtypes, and 10 isolates with unique PFGE patterns were analyzed blindly in 12 different laboratories by in-house protocols. In several laboratories a standardized PFGE protocol with a commercial kit was applied successfully as well. Eight of the centers correctly identified the genetic homogeneity of the identical isolates by both the in-house and standard protocols. Four of 12 laboratories failed to produce interpretable data by the standardized protocol, due to technical problems (primarily plug preparation). With the five related isolates, five of eight participants identified the same subtype interrelationships with both in-house and standard protocols. However, two participants identified multiple strain types in this group or classified some of the isolates as unrelated isolates rather than as subtypes. The remaining laboratory failed to distinguish differences between some of the related isolates by utilizing both the in-house and standardized protocols. There were large differences in the relative genome lengths of the isolates as calculated on the basis of the gel pictures. By visual inspection, the numbers of restriction fragments and overall banding pattern similarity in the three groups of isolates showed interlaboratory concordance, but centralized computer analysis of data from four laboratories yielded percent similarity values of only 85% for the group of identical isolates. The differences between the data sets obtained with in-house and standardized protocols could be the experimental parameters which differed with respect to the brand of equipment used, imaging software, running time (20 to 48 h), and pulsing conditions. In conclusion, it appears that the standardization of PFGE depends on controlling a variety of experimental intricacies, as is the case with other bacterial typing procedures.

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