scholarly journals Identification of a Novel Trimethoprim Resistance Gene, dfrK, in a Methicillin-Resistant Staphylococcus aureus ST398 Strain and Its Physical Linkage to the Tetracycline Resistance Gene tet(L)

2008 ◽  
Vol 53 (2) ◽  
pp. 776-778 ◽  
Author(s):  
Kristina Kadlec ◽  
Stefan Schwarz
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Dihydrofolate Reductase ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tetracycline Resistance ◽  
Sequence Type ◽  
Tetracycline Resistance Gene ◽  
Close Proximity ◽  
Physical Linkage ◽  
Dihydrofolate Reductases

ABSTRACT A novel trimethoprim resistance gene, designated dfrK, was detected in close proximity to the tetracycline resistance gene tet(L) on the ca. 40-kb plasmid pKKS2187 in a porcine methicillin (meticillin)-resistant Staphylococcus aureus isolate of sequence type 398. The dfrK gene encodes a 163-amino-acid dihydrofolate reductase that differs from all so-far-known dihydrofolate reductases.

scholarly journals Identification of a Plasmid-Borne Resistance Gene Cluster Comprising the Resistance Genes erm(T), dfrK, and tet(L) in a Porcine Methicillin-Resistant Staphylococcus aureus ST398 Strain

2009 ◽  
Vol 54 (2) ◽  
pp. 915-918 ◽  
Author(s):  
Kristina Kadlec ◽  
Stefan Schwarz
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Cluster ◽  
Resistance Gene ◽  
Streptococcus Pyogenes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tetracycline Resistance ◽  
Sequence Type ◽  
The Novel ◽  
Methicillin Resistant ◽  
Resistance Gene Cluster

ABSTRACT A novel plasmid-borne resistance gene cluster comprising the genes erm(T) for macrolide-lincosamide-streptogramin B resistance, dfrK for trimethoprim resistance, and tet(L) for tetracycline resistance was identified in a porcine methicillin-resistant Staphylococcus aureus sequence type 398 (ST398) strain. This erm(T)-dfrK-tet(L) region was flanked by copies of the novel IS element ISSau10. The erm(T) region resembled that of Streptococcus pyogenes plasmid pRW35. The erm(T) gene of pKKS25 was expressed constitutively due to a 57-bp deletion in the erm(T) translational attenuator.

scholarly journals Copresence oftet(K) andtet(M) in Livestock-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 398 Is Associated with Increased Fitness during Exposure to Sublethal Concentrations of Tetracycline

2016 ◽  
Vol 60 (7) ◽  
pp. 4401-4403 ◽  
Author(s):  
Jesper Larsen ◽  
Julie Clasen ◽  
Julie E. Hansen ◽  
Wilhelm Paulander ◽  
Andreas Petersen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Tetracycline Resistance ◽  
Tetracycline Resistance Gene ◽  
Methicillin Resistant ◽  
Content Type ◽  
Sublethal Concentrations ◽  
Staphylococcal Cassette Chromosome

ABSTRACTThe tetracycline resistance genetet(K) was shown to be integrated within the predominant staphylococcal cassette chromosomemec(SCCmec) element of Danish livestock-associated methicillin-resistantStaphylococcus aureusCC398 (LA-MRSA CC398). These LA-MRSA CC398 isolates already possessedtet(M), but the acquisition oftet(K) significantly improved their fitness at sublethal concentrations of tetracycline. Becausetet(K) is genetically linked to SCCmec, the use of tetracycline in food animals may have contributed to the successful spread of LA-MRSA CC398.

scholarly journals An IS257-Derived Hybrid Promoter Directs Transcription of a tetA(K) Tetracycline Resistance Gene in theStaphylococcus aureus Chromosomal mecRegion

2000 ◽  
Vol 182 (12) ◽  
pp. 3345-3352 ◽  
Author(s):  
Alice E. Simpson ◽  
Ronald A. Skurray ◽  
Neville Firth
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Gene Dosage ◽  
Tetracycline Resistance ◽  
Resistance Determinant ◽  
Tetracycline Resistance Gene ◽  
Methicillin Resistant ◽  
Hybrid Promoter ◽  
Genetic Rearrangements

ABSTRACT Transcription of the tetA(K) tetracycline resistance determinant encoded by an IS257-flanked cointegrated copy of a pT181-like plasmid, located within the chromosomal mecregion of a methicillin-resistant Staphylococcus aureusisolate, has been investigated. The results demonstrated that transcription of tetA(K) in this strain is directed by both an IS257-derived hybrid promoter, which is stronger than the native tetA(K) promoter in the autonomous form of pT181, and a complete outwardly directed promoter identified within one end of IS257. Despite lower gene dosage, the chromosomal configuration was shown to afford a higher level of resistance than that mediated by pT181 in an autonomous multicopy state. Furthermore, competition studies revealed that a strain carrying the chromosomaltetA(K) determinant exhibited a higher level of fitness in the presence of tetracycline but not in its absence. This finding suggests that tetracycline has been a selective factor in the emergence of strains carrying a cointegrated pT181-like plasmid in their chromosomes. The results highlight the potential of IS257to influence the expression of neighboring genes, a property likely to enhance its capacity to mediate advantageous genetic rearrangements.

Identification of a novel tetracycline resistance gene, tet(63), located on a multiresistance plasmid from Staphylococcus aureus

2020 ◽  
Author(s):  
Yao Zhu ◽  
Changzhen Wang ◽  
Stefan Schwarz ◽  
Wenyu Liu ◽  
Qin Yang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Resistance Gene ◽  
Efflux Pump ◽  
Tetracycline Resistance ◽  
Major Facilitator Superfamily ◽  
Whole Genome Sequence ◽  
Tetracycline Resistance Gene ◽  
Efflux Pump Inhibitor ◽  
Illumina Hiseq

Abstract Objectives To identify and characterize a novel tetracycline resistance gene on a multiresistance plasmid from Staphylococcus aureus SA01 of chicken origin. Methods MICs were determined by broth microdilution according to CLSI recommendations. The whole genome sequence of S. aureus SA01 was determined via Illumina HiSeq and Oxford Nanopore platforms followed by a hybrid assembly. The new tet gene was cloned and expressed in S. aureus. The functionality of the corresponding protein as an efflux pump was tested by efflux pump inhibition assays. Results A novel tetracycline resistance gene, tet(63), was identified on a plasmid in S. aureus SA01. The cloned tet(63) gene was functionally expressed in S. aureus and shown to confer resistance to tetracycline and doxycycline, and a slightly elevated MIC of minocycline. The tet(63) gene encodes a 459 amino acid efflux protein of the major facilitator superfamily that consists of 14 predicted transmembrane helices. The results of efflux pump inhibitor assays confirmed the function of Tet(63) as an efflux protein. The deduced amino acid sequence of the Tet(63) protein exhibited 73.0% identity to the tetracycline efflux protein Tet(K). The plasmid pSA01-tet, on which tet(63) was located, had a size of 25664 bp and also carried the resistance genes aadD, aacA-aphD and erm(C). Conclusions A novel tetracycline resistance gene, tet(63), was identified in S. aureus. Its location on a multiresistance plasmid might support the co-selection of tet(63) under the selective pressure imposed by the use of macrolides, lincosamides and aminoglycosides.

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