An Improved MLVF Method and Its Comparison with Traditional MLVF, spa Typing, MLST/SCCmec and PFGE for the Typing of Methicillin-Resistant Staphylococcus aureus

Du, Xue-Fei; Xiao, Meng; Liang, Hongyan; Sun, Zhe; Jiang, Yue-Hong; Chen, Guoyu; Meng, Xiaoyu; Zou, Gui-Ling; Zhang, Li; Liu, Yali; Zhang, Hui; Sun, Hongli; Jiang, Xiaofeng; Xu, Yingchun

doi:10.3390/ijms15010725

Cited by 13 publications

(9 citation statements)

References 33 publications

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“…Additionally, the high level of strain diversity may be related to the stringent cut-off of 100% similarity used in the present study. Other studies have used a 70 to 84% similarity value as a cut point to define S. aureus strain types (Boerema et al, 2006;Du et al, 2014). Although this will allow more grouping of isolates, it will also potentially group isolates that may not be epidemiologically related.…”

Section: Discussionmentioning

confidence: 99%

Molecular characterization of non-aureus Staphylococcus spp. from heifer intramammary infections and body sites

Adkins

Dufour

Spain

et al. 2018

Journal of Dairy Science

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The purpose of this study was to investigate non-aureus Staphylococcus spp. intramammary infections (IMI) in periparturient heifers and determine the relationship of precalving body site isolation with precalving IMI and postcalving IMI using molecular speciation and strain-typing methods. Primiparous heifers were enrolled at approximately 14 d before expected calving date. Precalving mammary quarter secretions and body site swabbing samples (teat skin, inguinal skin, muzzle, and perineum) were collected. Postcalving, mammary quarter milk samples were collected for culture and somatic cell counting. Precalving body site samples were cultured, and up to 10 staphylococcal colonies were saved for characterization. Staphylococcal isolates were speciated using matrix-assisted laser/desorption ionization time-of-flight mass spectrometry or sequencing of rpoB or tuf. Pulsed-field gel electrophoresis was used to strain type a subset of isolates. Overall, Staphylococcus chromogenes, Staphylococcus agnetis, and Staphylococcus simulans were the most common species identified in precalving mammary secretions, whereas S. chromogenes, Staphylococcus xylosus, and S. agnetis were the most common species found in postcalving milk samples. The most common species identified from body site samples were S. chromogenes, S. xylosus, and Staphylococcus haemolyticus. Mammary quarters that had a precalving mammary secretion that was culture positive for S. agnetis, S. chromogenes, or Staphylococcus devriesei had increased odds of having an IMI with the same species postcalving. A S. chromogenes IMI postcalving was associated with higher somatic cell count when compared with postcalving culture-negative quarters. Among heifers identified with a non-aureus Staphylococcus spp. IMI either precalving or postcalving, heifers that had S. agnetis or S. chromogenes isolated from their teat skin had increased odds of having the same species found in their precalving mammary secretions, and heifers with S. chromogenes, S. simulans, and S. xylosus isolated from their teat skin precalving were at increased odds of having an IMI with the same species postcalving. Overall, 44% of all heifers with a S. chromogenes IMI around the time of parturition had the same strain isolated from a body site. Based on pulsed-field gel electrophoresis, a high level of strain diversity was found.

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Section: Discussionmentioning

confidence: 99%

Molecular characterization of non-aureus Staphylococcus spp. from heifer intramammary infections and body sites

Adkins

Dufour

Spain

et al. 2018

Journal of Dairy Science

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“…The discriminatory power of PFGE for typing of S. aureus strains has been previously described (27,29,30) and has been measured in a range from 0.83 to 0.8887. Comparing several strain-typing methods to characterize S. aureus isolates of bovine origin, PFGE had the highest discriminatory power, followed by multilocus sequence typing (MLST), multilocus variable-number tandem-repeat analysis (MLVA), and then spa typing (29).…”

Section: Discussionmentioning

confidence: 99%

“…This was likely due to the small number of herds in the comparison, because a very stringent cutoff value (100% similarity) was used to define a strain type and because the PFGE strain type was part of the selection criteria for this study. Other studies have used 70% to 84% similarities as strain cutoff values (30,33), which would decrease the discriminatory power while allowing grouping of isolates that may not be epidemiologically related. Isolates with genetically indistinguishable restriction patterns can be considered the same strain type, while isolates that are closely related may have a single genetic alteration (a point mutation, insertion, or deletion) which can result in two to three band differences (19).…”

Section: Discussionmentioning

confidence: 99%

Comparison of Virulence Gene Identification, Ribosomal Spacer PCR, and Pulsed-Field Gel Electrophoresis for Typing of Staphylococcus aureus Strains Isolated from Cases of Subclinical Bovine Mastitis in the United States

2016

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bStaphylococcus aureus is one of the most important pathogens causing contagious mastitis in dairy cattle worldwide. The objectives of this study were to determine if recently described S. aureus genotype B was present among previously characterized isolates from cases of bovine intramammary infection in the United States and to compare pulsed-field gel electrophoresis (PFGE) to the combination of ribosomal spacer PCR (RS-PCR) and virulence gene identification for typing of S. aureus strains. The hypothesis was that isolates that were previously characterized as contagious would be identified as genotype B and that the results of the two strain-typing methods would be comparable. Isolates were selected from a collection of S. aureus isolates from eight dairy farms. Mammary quarter milk somatic cell count (SCC) and N-acetyl-␤-D-gluconaminidase (NAGase) activity data were known and used to evaluate strain pathogenicity. RS-PCR was performed with conventional gel electrophoresis, and PCR was used for toxin gene identification. RS-PCR patterns were associated with a specific virulence gene pattern, as previously reported. Five RS-PCR banding patterns were identified. None of the isolates were characterized as genotype B. No association between RS-PCR types and milk SCC was found; however, NAGase activity was significantly higher in milk from mammary glands infected with RS-PCR banding type 1 (RSP type 1) than in milk from those infected with RSP type 2. The discriminatory power values were 1.0 and 0.46 for PFGE and RS-PCR, respectively. These data suggest that genotype B may have a limited geographic distribution and that PFGE is more discriminatory than RS-PCR performed with conventional gel electrophoresis for typing of S. aureus isolates of bovine origin. Staphylococcus aureus is one of the most important pathogens causing contagious mastitis in dairy cattle worldwide (1-3). Although S. aureus is considered a contagious intramammary pathogen and spreads from cow to cow during milking, strains of this agent are most often farm specific, and there is generally a predominant strain in a herd (4). Several methods have been used to characterize and determine genetic subtypes or strain types of this pathogen, allowing identification of the predominant contagious strains. Methods commonly used for typing of S. aureus strains include pulsed-field gel electrophoresis (PFGE) (5), spa typing (6), and multilocus sequence typing (MLST) (7). Although labor-intensive, PFGE is considered the gold standard strain-typing method for this genus and species (8). Currently, no accurate, fast, and inexpensive tool enabling one to determine which strains are important and likely to be a significant problem for a farm is readily available.Recent studies reported from Switzerland used ribosomal spacer-PCR (RS-PCR) to characterize S. aureus isolated from bovine milk samples and found various strain types, classified as genotypes, of S. aureus possessing different virulence and pathogenicity factors (9-11). Several genotypes were identified...

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“…The amplification and sequencing of the 24 bp polymorphic zone X of the spa gene gives several repeats which can be assigned an alpha-numerical code and the S. aureus strain can be determined [72]. Spa typing has become a widely distributed typing technique for S. aureus since it is simple and cheap, with greater discrimination power when compared to MLST [73]. At the beginning of 2020, more than 19,000 different spa-types were registered in the Ridom SpaServer.…”

Section: Spa Typingmentioning

confidence: 99%

Molecular Epidemiology of Staphylococcus aureus Lineages in Wild Animals in Europe: A Review

et al. 2020

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Staphylococcus aureus is an opportunist pathogen that is responsible for numerous types of infections. S. aureus is known for its ability to easily acquire antibiotic resistance determinants. Methicillin-resistant S. aureus (MRSA) is a leading cause of infections both in humans and animals and is usually associated with a multidrug-resistant profile. MRSA dissemination is increasing due to its capability of establishing new reservoirs and has been found in humans, animals and the environment. Despite the fact that the information on the incidence of MRSA in the environment and, in particular, in wild animals, is scarce, some studies have reported the presence of these strains among wildlife with no direct contact with antibiotics. This shows a possible transmission between species and, consequently, a public health concern. The aim of this review is to better understand the distribution, prevalence and molecular lineages of MRSA in European free-living animals.

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An Improved MLVF Method and Its Comparison with Traditional MLVF, spa Typing, MLST/SCCmec and PFGE for the Typing of Methicillin-Resistant Staphylococcus aureus

Cited by 13 publications

References 33 publications

Molecular characterization of non-aureus Staphylococcus spp. from heifer intramammary infections and body sites

Molecular characterization of non-aureus Staphylococcus spp. from heifer intramammary infections and body sites

Comparison of Virulence Gene Identification, Ribosomal Spacer PCR, and Pulsed-Field Gel Electrophoresis for Typing of Staphylococcus aureus Strains Isolated from Cases of Subclinical Bovine Mastitis in the United States

Molecular Epidemiology of Staphylococcus aureus Lineages in Wild Animals in Europe: A Review

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