Comparison of Fingerprinting Methods for Typing Methicillin-Resistant Staphylococcus aureus Sequence Type 398

Abstract

This study evaluates the multiple-locus variable-number tandem-repeat assay (MLVA) and pulsed-field gel electrophoresis (PFGE) when using restriction enzymes BstZI, SacII, and ApaI to fingerprint a diverse collection of methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) sequence type 398 (ST398) isolates. These isolates had been characterized previously by multilocus sequence typing, spa typing, and staphylococcal cassette chromosome mec (SCCmec) typing. Typeability and discriminatory power were analyzed, and the concordance between the various methods was determined. All MRSA ST398 isolates were typeable by the MLVA and PFGE using BstZI, SacII, and ApaI. With each method, the MRSA ST398 isolates formed a separate group from the two non-ST398 MRSA strains. PFGE, performed with any of the three restriction enzymes, had the most discriminatory power, followed by MLVA, spa typing, and SCCmec typing. The MLVA showed the highest concordance with PFGE using ApaI and spa typing. As further expressed by the Wallace coefficient, the MLVA type was poorly predicted by spa typing, whereas the spa type was well predicted by MLVA. PFGE, using a combination of all three restriction enzymes, had the highest concordance with the MLVA but had a low probability of being predicted by MLVA. PFGE, using a combination of all three restriction enzymes, was able to predict SCCmec type and MLVA type completely and had a high probability of predicting spa type. Both the MLVA and PFGE could be used to discriminate among the MRSA ST398 isolates. Although the MLVA is a faster technique, PFGE had more discriminatory power than the MLVA, especially when a combination of restriction enzymes was used.

Livestock-Associated MRSA and Its Current Evolution

“…This was a result of the action of C5-cytosine methyltransferase, which modifies the consensus sequence recognized by SmaI [115,116]. Although several enzymes were used as an alternative [117], their profiles were not comparable with those generated by SmaI in non-CC398 isolates. To overcome this problem, the use of Cfr9I, a neoschizomer (an enzyme that cuts within the same recognition sequence) of SmaI, was proposed [116], and this enzyme was used successfully for PFGE typing of CC398 isolates [59].…”

Suspected Goat-to-Human Transmission of Methicillin-Resistant Staphylococcus aureus Sequence Type 398

“…Four weeks after isolation of human MRSA, nasal swabs from the person who tested positive were screened and remained positive (isolate 16H). All MRSA isolates were confirmed as described above and further investigated by PCR targeting Panton-Valentine leukocidin (PVL) genes (5), staphylococcal cassette chromosome mec (SCCmec) typing using the multiplex PCR method (6), staphylococcal protein A (spa) typing (7) (results of spa typing were interpreted by using BioNumerics version 5.1 software), and two different multilocus variable-number tandem-repeat analyses (MLVA): MLVA-14 Orsay (8) and multiplex PCR MLVA (9). Multilocus sequence typing (MLST) was performed on all isolates.…”

Preliminary evaluation of good sampling locations on a pig carcass for livestock-associated MRSA isolation

“…Analysis was performed in SPSS statistics 19 (IBM, Chicago, IL, US) and for all analyses, P < 0.05 was considered significant. A CC398-specific PCR, targeting the restriction-modification system encoding sau1hsdS1, and PFGE using BstZI (Promega, Madison, WI, US) as a restriction enzyme were performed with all obtained isolates as described by Stegger et al (2011) and Rasschaert et al (2009), respectively. The obtained PFGE profiles were analyzed with Bionumerics version 6.5 (Applied Maths, St.-Martens-Latem, BE) using the unweighted pair group method using averages (UPGMA) with the Dice coefficient (tolerance 1%, tolerance change 1% and optimization 1%).…”