Novel Type XII Staphylococcal Cassette Chromosome mec Harboring a New Cassette Chromosome Recombinase, CcrC2

Abstract

bExcision and integration of staphylococcal cassette chromosome mec (SCCmec) are mediated by cassette chromosome recombinases (Ccr), which play a crucial role in the worldwide spread of methicillin resistance in staphylococci. We report a novel ccr gene, ccrC2, in the SCCmec of a Staphylococcus aureus isolate, BA01611, which showed 62.6% to 69.4% sequence identities to all published ccrC1 sequences. A further survey found that the ccrC2 gene was mainly located among coagulase-negative staphylococci (CoNS) and could be found in staphylococcal isolates from China, the United States, France, and Germany. The ccr gene complex harboring the ccrC2 gene was designated a type 9 complex, and the SCCmec of BA01611 was considered a novel type and was designated type XII (9C2). This novel SCCmec element in BA01611 was flanked by a pseudo-SCC element (⌿SCC BA01611 ) carrying a truncated ccrA1 gene. Both individual SCC elements and a composite SCC were excised from the chromosome based on detection of extrachromosomal circular intermediates. We advocate inclusion of the ccrC2 gene and type 9 ccr gene complex during revision of the SCCmec typing method.

Distribution of the Most Prevalent Spa Types among Clinical Isolates of Methicillin-Resistant and -Susceptible Staphylococcus aureus around the World: A Review

“…The spa and SCC mec typing methods focus on two distinct locations within the genome of S. aureus . The last SCC mec type reported in 2015 in Germany was the SCC mec type XII (Wu et al, 2015), whereas the studies assessed in this review, have only ascertained limited SCC mec types (I, II, II, IV, and V). Moreover, a significant number of spa types have not been associated to any specific SCC mec type and the number of studies which have assessed SCC mec typing for the prevalent spa types are limited.…”

Bacteria from Animals as a Pool of Antimicrobial Resistance Genes

“…This MGE has been more extensively studied for S. aureus , since this is the most important Staphylococcus species for the human health. To date, eleven major SCC mec types carrying mecA have been described in methicillin resistant S. aureus (MRSA), which have been assigned on the characterization of its two essential components the mec and ccr complexes [84,85,86]. The mec -gene complex corresponded to the mecA operon variants, which can include functional and/or truncated regulatory genes.…”

A Review of Staphylococcal Cassette Chromosome mec (SCCmec) Types in Coagulase-Negative Staphylococci (CoNS) Species

“…The ccrC2 gene was found to be mainly located among CoNS and could be found in staphylococcal isolates from the USA, France, Germany, and China. Wu et al (65) categorised the ccr gene complex under type 9, while the SCCmec of BA01611 was indicated as a novel type designated as type XII (9C2). This novel SCCmec element in BA01611 was covered by a pseudo SCC element 22 (ΨSCCBA01611) that carries a truncated ccrA1.…”