Mutagenesis of extrachromosomal genetic determinants for exfoliative toxin B and bacteriocin R1 synthesis in Staphylococcus aureus after plasmid transfer by protoplast fusion.

Aims. To quantify the presence of SCCmec types and virulence genes among Staphylococcus aureus colonizing and infecting patients from a teaching hospital. Methods. We analyzed 225 and 84 S. aureus isolates recovered from surveillance and clinical cultures, respectively. Strains were studied for the presence and type of SCCmec, as well as for several virulence genes. Univariate and multivariable analysis were performed in order to identify predictors of invasiveness (defined as isolation from clinical cultures). Results. The presence of SCCmec types III (OR, 2.19, 95% CI, 1.08–4.45) and IV (OR, 5.28 95% CI, 1.35–20.63) and of genes coding for exfoliative toxin B (etb, OR, 6.38, 95% CI, 1.48–27.46) and Panton-Valentine leukocidin (pvl, OR, 2.38, 95% CI, 1.16–4.86) was independently associated with invasiveness. Conclusions. SCCmec types III and IV and virulence genes are associated with greater invasiveness of S. aureus. Patients colonized with methicillin-resistant S. aureus, as well as with strains harboring etb or pvl, may be prone to develop invasive disease. Infection-preventing strategies should be more intensively applied to this group.

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Identification of Genes Encoding Two-Component Lantibiotic Production in Staphylococcus aureus C55 and Other Phage Group II S. aureus Strains and Demonstration of an Association with the Exfoliative Toxin B Gene

Infection and Immunity ◽

10.1128/iai.67.8.4268-4271.1999 ◽

1999 ◽

Vol 67 (8) ◽

pp. 4268-4271 ◽

Cited By ~ 44

Author(s):

Maduwe A. D. B. Navaratna ◽

Hans-Georg Sahl ◽

John R. Tagg

Keyword(s):

Staphylococcus Aureus ◽

Elevated Temperatures ◽

Toxin B ◽

Phage Group ◽

Exfoliative Toxin ◽

Two Component ◽

Genes Encoding ◽

Peptide System ◽

Group Ii ◽

Considerable Homology

ABSTRACT The production of exfoliative toxin B (ET-B), but not ET-A, was shown to be specifically associated with production of a highly conserved two-component lantibiotic peptide system in phage group IIStaphylococcus aureus. Two previously studied but incompletely characterized S. aureus bacteriocins, staphylococcins C55 and BacR1, were found to be members of this lantibiotic system, and considerable homology was also found with the two-component Lactococcus lactis bacteriocin, lacticin 3147. sacαA and sacβA, the structural genes of the lantibiotics staphylococcins C55α and C55β and two putative lantibiotic processing genes, sacM1 and sacT, were localized together with the ET-B structural gene to a single 32-kb plasmid in strain C55. Irreversible loss of both ET-B and two-component lantibiotic production occurs during laboratory passage of ET-B-positive S. aureus strains, particularly at elevated temperatures.

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Emergence of Staphylococcus aureus Carrying Multiple Drug Resistance Genes on a Plasmid Encoding Exfoliative Toxin B

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01062-13 ◽

2013 ◽

Vol 57 (12) ◽

pp. 6131-6140 ◽

Cited By ~ 11

Author(s):

Junzo Hisatsune ◽

Hideki Hirakawa ◽

Takayuki Yamaguchi ◽

Yasuyuki Fudaba ◽

Kenshiro Oshima ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Drug Resistance ◽

Resistance Genes ◽

Multiple Drug Resistance ◽

Antimicrobial Treatment ◽

Multiple Drug ◽

Toxin Gene ◽

Toxin B ◽

Content Type ◽

Exfoliative Toxin

ABSTRACTWe report the complete nucleotide sequence and analysis of pETBTY825, aStaphylococcus aureusTY825 plasmid encoding exfoliative toxin B (ETB).S. aureusTY825 is a clinical isolate obtained from an impetigo patient in 2002. The size of pETBTY825, 60.6 kbp, was unexpectedly larger than that of the archetype pETBTY4(∼30 kbp). Genomic comparison of the plasmids shows that pETBTY825has the archetype pETBTY4as the backbone and has a single large extra DNA region of 22.4 kbp. The extra DNA region contains genes for resistance to aminoglycoside [aac(6′)/aph(2″)], macrolide (msrA), and penicillin (blaZ). A plasmid deletion experiment indicated that these three resistance elements were functionally active. We retrospectively examined the resistance profile of the clinical ETB-producingS. aureusstrains isolated in 1977 to 2007 using a MIC determination with gentamicin (GM), arbekacin (ABK), and erythromycin (EM) and by PCR analyses foraac(6′)/aph(2″) andmsrAusing purified plasmid preparations. The ETB-producingS. aureusstrains began to display high resistance to GM, which was parallel with the detection ofaac(6′)/aph(2″) andmecA, after 1990. Conversely, there was no significant change in the ABK MIC during the testing period, although it had a tendency to slightly increase. After 2001, isolates resistant to EM significantly increased; however,msrAwas hardly detected in ETB-producingS. aureusstrains, and only five isolates were positive for bothaac(6′)/aph(2″) andmsrA. In this study, we report the emergence of a fusion plasmid carrying the toxin geneetband drug resistance genes. Prevalence of the pETBTY825carrier may further increase the clinical threat, since ETB-producingS. aureusis closely related to more severe impetigo or staphylococcal scalded-skin syndrome (SSSS), which requires a general antimicrobial treatment.

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