Abstract
ObjectiveTo determine the genetic structure of ermB-positive Tn1546-like mobile elements in methicillin-resistant Staphylococcus aureus (MRSA) from mainland China.MethodsA total of 271 erythromycin-resistant MRSA isolates were isolated from Sir Run Run Shaw Hospital (SRRSH) from 2013 to 2015. Whole-genome sequencing was performed for the ermB-positive strains, and the genetic environment of the ermB genes was analyzed. Southern hybridization analysis and transformation tests were performed to confirm the location of the ermB gene.ResultsA total of 64 isolates (64/271, 23.6%) were ermB-positive strains, with 62 strains (62/64, 96.9%) belonging to the CC59 clone. The other two strains, SR130 and SR231, belonging to CC5-ST965, both harbored 14,567 bp ermB-positive Tn1546-like elements and displayed multidrug-resistant profiles. PFGE followed by Southern blot demonstrated that the ermB genes were located on the plasmids of both SR130 and SR231, while two copies of ermB were located on the chromosome of SR231. Further sequencing demonstrated that SR231 carried one Tn1546-ermB elements in the plasmid and two identical copies integrated on the chromosome, which had 99.99% identity to the element in the plasmid of SR130. The Tn1546-ermB elements were highly similar (100% coverage, >99.9% identity) to the element Tn6636 reported in a previous study from Taiwan. The plasmids (pSR130 and pSR231) harboring ermB-positive Tn1546-like elements were also identical to the mosaic plasmid pNTUH_5066148. However, conjugation of ermB-carrying plasmids of SR130 and SR231 were failed after triple repeats.ConclusionMultiple copies of ermB-positive Tn1546-like mobile elements were found in CC5-ST965 MRSA from mainland China, showing the wide dissemination of these Enterococcus faecium-originated ermB-positive Tn1546-like elements. Molecular epidemiological study of Tn1546-like elements is essential to avoid the spreading of resistant determinants.
Highlights
Staphylococcus aureus is an important Gram-positive pathogen that can cause a variety of infectious diseases and result in increased mortality (Su et al, 2013)
We investigated the prevalence of the ermB gene among methicillin-resistant S. aureus (MRSA) isolates isolated from 2013 to 2015 in Sir Run Run Shaw Hospital (SRRSH) and analyzed the structure of the mobile element harboring the ermB gene
Most (62/64, 96.9%) of the ermB-positive MRSA belonged to the CC59 clone, except for SR130 and SR231 (2/64, 3.1%)
Summary
Staphylococcus aureus is an important Gram-positive pathogen that can cause a variety of infectious diseases and result in increased mortality (Su et al, 2013). The antibiotic resistance problem with S. aureus has attracted worldwide attention. In addition to methicillin-resistant S. aureus (MRSA), macrolide resistance is a common and severe problem. A meta-analysis study in a healthy Chinese population found that 88% of MRSA isolates were resistant to erythromycin (Wu et al, 2019). Antimicrobial surveillance of bacterial isolates from patients hospitalized with community-acquired skin infections in Europe, Asia and Latin America showed that 56% of MRSA isolates were not susceptible to erythromycin (Sader et al, 2019). Erythromycin resistance in MRSA is a problem that is worthy of attention
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
