Genomes and Genes
Affiliation: University of Chicago
- Novel type of staphylococcal cassette chromosome mec identified in community-acquired methicillin-resistant Staphylococcus aureus strainsXiao Xue Ma
Department of Bacteriology, Juntendo University, Tokyo, Japan
Antimicrob Agents Chemother 46:1147-52. 2002..Consistent with the strains' susceptibilities to various non-beta-lactam antibiotics, the type IV SCCmec was devoid of any antibiotic resistance genes other than the mecA gene...
- Community-acquired methicillin-resistant Staphylococcus aureus: the role of Panton-Valentine leukocidinSusan Boyle-Vavra
Department of Pediatrics, Section of Infectious Diseases, University of Chicago, Chicago, IL 60637, USA
Lab Invest 87:3-9. 2007..The second aim is to outline the progress in understanding the role of PVL in CA-MRSA pathogenesis...
- The VraS/VraR two-component regulatory system required for oxacillin resistance in community-acquired methicillin-resistant Staphylococcus aureusSusan Boyle-Vavra
Department of Pediatrics Section of Pediatric Infectious Diseases, The University of Chicago, Chicago, IL 60637, USA
FEMS Microbiol Lett 262:163-71. 2006..Therefore, the vraS/vraR regulatory system plays a crucial role in allowing MRSA to respond to beta-lactams by regulation of a gene target other than the known effectors of methicillin resistance...
- Successful multiresistant community-associated methicillin-resistant Staphylococcus aureus lineage from Taipei, Taiwan, that carries either the novel Staphylococcal chromosome cassette mec (SCCmec) type VT or SCCmec type IVSusan Boyle-Vavra
Department of Pediatrics, Section of Infectious Diseases, University of Chicago, IL, 60637, USA
J Clin Microbiol 43:4719-30. 2005..SCCmec V(T) is a novel SCCmec variant that is found in multiply resistant CAMRSA strains with sequence type 59 in Taipei in association with the PVL leukotoxin genes...
- Transcriptional induction of the penicillin-binding protein 2 gene in Staphylococcus aureus by cell wall-active antibiotics oxacillin and vancomycinSusan Boyle-Vavra
Department of Pediatrics, The University of Chicago, Illinois 60637, USA
Antimicrob Agents Chemother 47:1028-36. 2003..These data support the idea that pbpB expression is modulated by a trans-acting factor in response to the presence of the cell wall-active antibiotics vancomycin and oxacillin...
- CodY deletion enhances in vivo virulence of community-associated methicillin-resistant Staphylococcus aureus clone USA300Christopher P Montgomery
Section of Critical Care, University of Chicago, Chicago, Illinois, USA
Infect Immun 80:2382-9. 2012..These results demonstrate that CodY is active in USA300 and that CodY-mediated repression restrains the virulence of USA300...
- Molecular epidemiology of methicillin-resistant Staphylococcus aureus, rural southwestern AlaskaMichael Z David
Department of Pediatrics, University of Chicago, 5841 S Maryland Ave, MC 6054, Chicago, IL 60637, USA
Emerg Infect Dis 14:1693-9. 2008..1% were ST8. Among 120 prospective isolates, 57.5% were clindamycin resistant. CA-MRSA epidemiology in southwestern Alaska differs from that in the lower 48 states; ST8 strains were rarely identified and clindamycin resistance was common...
- Comparison of virulence in community-associated methicillin-resistant Staphylococcus aureus pulsotypes USA300 and USA400 in a rat model of pneumoniaChristopher P Montgomery
Department of Pediatrics, Section of Critical Care Medicine, University of Chicago, Illinois 60637, USA
J Infect Dis 198:561-70. 2008..The explanation for this shift is unclear. We hypothesized that USA300 must be more pathogenic--specifically, that USA300 would have increased virulence when compared with USA400 in an animal model...
- Importance of the global regulators Agr and SaeRS in the pathogenesis of CA-MRSA USA300 infectionChristopher P Montgomery
Section of Critical Care, Department of Pediatrics, University of Chicago, Chicago, Illinois, United States of America
PLoS ONE 5:e15177. 2010..We conclude that agr and saeRS each independently contribute to the remarkable virulence of USA300, likely by means of their effects on expression of secreted toxins...
- Clinical importance of purulence in methicillin-resistant Staphylococcus aureus skin and soft tissue infectionsSusan E Crawford
Department of Pediatrics, The University of Chicago, Chicago, IL 60637, USA
J Am Board Fam Med 22:647-54. 2009..We assessed whether predictive clinical characteristics of presumptive MRSA infections can be identified to guide choice of empiric antibiotic therapy...
- MRSA USA300 at Alaska Native Medical Center, Anchorage, Alaska, USA, 2000-2006Michael Z David
Department of Medicine, University of Chicago, 5841 S Maryland Ave, MC6054, Chicago, IL 60637, USA
Emerg Infect Dis 18:105-8. 2012..Among Anchorage-region residents, USA300 was a minor constituent among MRSA isolates in 2000-2003 (11/68, 16%); by 2006, USA300 was the exclusive genotype identified (10/10)...
- What is community-associated methicillin-resistant Staphylococcus aureus?Michael Z David
Infectious Diseases Section, Department of Pediatrics, The University of Chicago, IL 60637, USA
J Infect Dis 197:1235-43. 2008..We sought to determine whether the absence or presence of these risk factors still predicts the phenotypic or genotypic characteristics of MRSA strains...
- Improved oxacillin treatment outcomes in experimental skin and lung infection by a methicillin-resistant Staphylococcus aureus isolate with a vraSR operon deletionDae Sun Jo
Section of Infectious Diseases, Department of Pediatrics, The University of Chicago, Chicago, IL 60637, USA
Antimicrob Agents Chemother 55:2818-23. 2011..These findings provide proof-of-principle for development of a new antibiotic that could restore the usefulness of oxacillin against MRSA by inhibiting VraS or VraR...
- Contrasting pediatric and adult methicillin-resistant Staphylococcus aureus isolatesMichael Z David
University of Chicago, Chicago, Illinois 60637, USA
Emerg Infect Dis 12:631-7. 2006..In our region, clindamycin is an appropriate empiric therapy of community-associated MRSA infection in children but should be used with caution in adults...
- VraSR two-component regulatory system and its role in induction of pbp2 and vraSR expression by cell wall antimicrobials in Staphylococcus aureusShaohui Yin
Department of Pediatrics, The University of Chicago, 5841 S. Maryland Ave, MC 6054, Chicago, Illinois 60637, USA
Antimicrob Agents Chemother 50:336-43. 2006..However, when a disk diffusion assay that can detect induction of genes over an extended time period was used, induction of the pbp2 operon was mediated by some beta-lactams, including oxacillin; this induction was independent of vraS...
- Staphylococcus aureus sepsis and the Waterhouse-Friderichsen syndrome in childrenPatricia V Adem
Department of Pathology, University of Chicago, USA
N Engl J Med 353:1245-51. 2005..aureus, one susceptible to methicillin and two resistant to methicillin, underscores the close relationship between virulent methicillin-susceptible S. aureus and methicillin-resistant S. aureus isolates now circulating in the community...
- Predominance of methicillin-resistant Staphylococcus aureus among pathogens causing skin and soft tissue infections in a large urban jail: risk factors and recurrence ratesMichael Z David
Section of Infectious Diseases, Department of Medicine, The University of Chicago, 5841 S Maryland Ave, MC 6054, Chicago, IL 60637, USA
J Clin Microbiol 46:3222-7. 2008..6%) of MSSA SSTI patients (P = 0.004). MRSA is the predominant cause of SSTIs requiring culture in the jail. Few risk factors differentiated MRSA from MSSA SSTIs, and detainee patients with MRSA SSTIs are at high risk for recurrent SSTIs...
- Association of high-level mupirocin resistance and multidrug-resistant methicillin-resistant Staphylococcus aureus at an academic center in the midwestern United StatesAdriana Cadilla
Section of Infectious Diseases, Department of Pediatrics, The University of Chicago, 5841 S Maryland Ave, MC 6054, Chicago, IL 60637, USA
J Clin Microbiol 49:95-100. 2011..However, CA- and HA-MRSA genotypes were more evenly distributed among mupA-positive isolates compared to mupA-negative MDR isolates. Thus, in Chicago, mupA is circulating among both CA- and HA-MRSA backgrounds...
- Methicillin-susceptible Staphylococcus aureus as a predominantly healthcare-associated pathogen: a possible reversal of roles?Michael Z David
Department of Pediatrics, The University of Chicago, Chicago, Illinois, United States of America
PLoS ONE 6:e18217. 2011..We hypothesized that, as MRSA infections became more common among S. aureus infections in the community, perhaps MSSA infections had become more important as a cause of healthcare-associated infection...
- A novel methicillin-resistance cassette in community-acquired methicillin-resistant Staphylococcus aureus isolates of diverse genetic backgroundsRobert S Daum
Department of Pediatrics, University of Chicago, Chicago, Illinois 60637, USA
J Infect Dis 186:1344-7. 2002..SCCmec type IV is present on the genome of CA-MRSA isolates. Its relatively small size and presence in isolates of diverse genetic backgrounds suggest that it may spread among S. aureus isolates...
- Resistance to autolysis in vancomycin-selected Staphylococcus aureus isolates precedes vancomycin-intermediate resistanceSusan Boyle-Vavra
Department of Pediatrics, The University of Chicago, Chicago, Illinois 60637, USA
Antimicrob Agents Chemother 47:2036-9. 2003..Strains with the vancomycin-induced Triton X-100 resistance phenotype produced active murein hydrolases but were resistant to lysis by murein hydrolases...
- Complex molecular epidemiology of methicillin-resistant staphylococcus aureus isolates from children with cystic fibrosis in the era of epidemic community-associated methicillin-resistant S aureusDaniel Glikman
Section of Infectious Diseases, Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
Chest 133:1381-7. 2008..We sought to characterize MRSA strains from these patients and compare them with MRSA strains from non-CF pediatric patients...
- Reliability of the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) assay in detecting MRSA isolates with a variety of genotypes from the United States and TaiwanSusan Boyle-Vavra
Department of Pediatrics, University of Chicago, KCBD 4152, 900 E 57th Street, Chicago, IL 60637, USA
J Clin Microbiol 48:4546-51. 2010..In summary, the BD GeneOhm MRSA assay had a high rate of detection of MRSA isolates harboring common and uncommon SCCmec types from the United States and Taiwan...
- Evidence for a continuum of decreased vancomycin susceptibility in unselected Staphylococcus aureus clinical isolatesFarid M Hussain
Department of Pediatrics, University of Chicago, Chicago, Illinois 60637, USA
J Infect Dis 186:661-7. 2002..aureus isolates. These observations suggest that glycopeptide-intermediate-like S. aureus isolates are circulating undetected and that a continuum of decreased susceptibility exists in unselected isolates...
- The arginine catabolic mobile element is not associated with enhanced virulence in experimental invasive disease caused by the community-associated methicillin-resistant Staphylococcus aureus USA300 genetic backgroundChristopher P Montgomery
Department of Pediatrics, Section of Critical Care Medicine, University of Chicago, Chicago, IL 60637, USA
Infect Immun 77:2650-6. 2009..Nor was the presence of ACME associated with increased dermonecrosis in a model of skin infection. We conclude that ACME is not necessary for virulence in rodent models of CA-MRSA USA300 pneumonia or skin infection...
- VraT/YvqF is required for methicillin resistance and activation of the VraSR regulon in Staphylococcus aureusSusan Boyle-Vavra
Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
Antimicrob Agents Chemother 57:83-95. 2013..aureus. We also provide the first in vivo proof of principle for using VraT as a sole target to resensitize MRSA to β-lactams...
- Comparative genome sequencing of an isogenic pair of USA800 clinical methicillin-resistant Staphylococcus aureus isolates obtained before and after daptomycin treatment failureSusan Boyle-Vavra
Department of Pediatrics, University of Chicago, KCBD 4152, 900 E 57th Street, Chicago, IL 60657, USA
Antimicrob Agents Chemother 55:2018-25. 2011..This is the first study to use pyrosequencing to compare the genomes of a daptomycin-susceptible/resistant MRSA isolate pair obtained during failed daptomycin therapy in humans...
- Community-associated methicillin-resistant Staphylococcus aureus isolates causing healthcare-associated infectionsCynthia L Maree
David Geffen School of Medicine, University of California, Los Angeles, California90509, USA
Emerg Infect Dis 13:236-42. 2007..In conclusion, MRSA isolates phenotypically similar to CA strains have become the predominant isolates associated with HA-MRSA in our hospital...