David W. Hecht, M.D., M.S., M.B.A.
The John W. Clarke Professor and Chairman

M.D. Loyola University Chicago

Molecular Microbiologist

 

Mechanisms by which Bacteroides fragilis  
causes serious infections and acquires resistance to antimicrobial agents

David Hecht
   

 

Bacteroides  fragilis is the most significant anaerobic  pathogen in humans, which is attributable  to a number of virulence factors and to its ability to acquire antibiotic resistance by DNA transfer. Although  transfer  of antibiotic  resistance  has been demonstrated  in vitro, the mechanisms  of DNA transfer are unknown.   To date, three types of transfer  factors have been identified.   They include conjugal plasmids, mobilizable transposons, and tetracycline transfer elements.   These factors function independently but also interact with one another to facilitate and enhance transfer.

The goal of my laboratory's research has been to determine the mechanisms of transfer of plasmids pBFTM10 and pLV22a and the mobilizable transposon Tn5520 as models for understanding DNA transfer in B. fragilis.

 

Selected Publications

Snydman DR, Jacobus NV, McDermott LA, Golan Y,Goldstein EJ,  Harrell LJ, Jenkins S,Newton D, Pierson C, Rosenblatt J,  Venezia R, Gorbach S, Queenan AM, Hecht DW.  Update on Resistance of B. fragilis Group and Related Species with Special Attention to Carbapenems 2006-2009. Anaerobe, 2011, 17:147-51.

Park M, Rooney AP, Hecht DW, Li J, McClane BA, Nayak R, Paine DD and Rafii F. Phenotypic and genotypic characterization of tetracycline and minocycline resistance in Clostridium perfringens. Arch Micro 2010, 192:803-10.

Snydman D, Jacobus N, McDermott L, Golan Y, Hecht DW, Goldstein E, Harrell L, Jenkins S, Newton D, Pierson C, Rihs J, Yu V, Venezia R, Finegold S, Rosenblatt J, Gorbach S. Lessons Learned from the Anaerobe Survey: Historical Perspective and Review of the Most Recent Data (2005-2007).
Clinical Infectious Diseases,2010,50:S26-33.

Hurtuk MG, He LK, Szilagyi A, Gamelli RL, Hecht DW, Kennedy RH, Rhys-Williams W, Love WG, Shankar R, The novel antibacterial drug XF-70 is a potent inhibitor of Staphylococcus aureus infection of the burn wound, J Burn Care Res. 2010 May-Jun;31(3):462-9.PMID: 20453736

Johnson S, Schriever C, Patel U, Patel T, Hecht DW, Gerding DN. Rifaximin Redux: treatment of recurrent   Clostridium   difficile   infections   with  rifaximin   immediately   post-vancomycin   treatment. Anaerobe. 15(6):290-1 (2009).

O'Connor JR, Galang MA, Sambol SP, Hecht DW, Vedantam G, Gerding DN, Johnson S. 2008. Rifampin  and  rifaximin  resistance  in  clinical  isolates  of  Clostridium   difficile.  Antimicrob  Agents Chemother. 52(8):2813-7.

Snydman DR, Jacobus NV, McDermott LA, Golan Y, Hecht DW, Goldstein EJ, Harrell L, Jenkins S, Newton  D,  Pierson  C,  Rihs  JD,  Yu  VL,  Venezia  R,  Finegold  SM,  Rosenblatt  JE,  Gorbach  SL, Lessons learned from the anaerobe survey: historical perspective and review of the most recent data (2005-2007).

Sears CL, Islam S, Saha A, Arjumand M, Haque Alam N, Faruque ASG, Salam MA, Shin J, Hecht DW, Weintraub A, Sack RB, Qadri F. Enterotoxigenic  Bacteroides fragilis infection is associated with inflammatory diarrhea. Clin Infect Diseases (2008, in press).

Thomas J, Hecht DW. Interaction of Bacteroides  fragilis pLV22a relaxase Transfer DNA with E. coli
RP4 TraG coupling protein. Molecular Microbiology 66(4):948-60, 2007.

Hecht, DW, Kos I, Knopf S, Vedantam G. Characterization of BctA, a mating apparatus protein required for transfer of the Bacteroides fragilis conjugal element BTF-37. Res Microbiol, 158(7):600-7
, 2007.

Hecht  DW,  Galang  M,  Osmolski  JR,  Johnson  SB,  Gerding  DN.  In  Vitro  activity  of  Fifteen
Antimicrobial Agents Against 110 Toxigenic Clostridium difficile Clinical Isolates Collected from
1983-2004. Antimicrob Agents Chemother 51(8):2716-9, 2007.

Hecht DW. Routine anaerobic blood cultures: back where we started? Clin Infect Dis, 44:901-3, 2007 (editorial commentary).

Snydman DR, Jacobus NV, McDermott LA, Ruthazer R, Golan Y, Goldstein EJ, Finegold SM, Harrell LJ, Hecht DW, Jenkins SG, Pierson C, Venezia R, Yu V, Rihs J, Gorbach SL. National Survey on the Susceptibility of Bacteroides fragilis Group: Report and Analysis of Trends in the United States from
1997 to 2004. Antimicrob Agents Chemother.51:1649-55, 2007.

Barron WM, Reed RL, Forsythe S, Hecht DW, Glen J, Murphy B, Lach R, Flores S, Tu J, Concklin M. Successful Implementation of Computerized Provider Order Entry Using an Existing Clinical Information System. Joint Commission Journal on Quality and Patient Safety 32:506-516, 2006.

Sprandel KA, Drusano GL, Hecht DW, Rotschafer JC, Danziger LH, Rodvold KA. Population pharmacokinetic modeling and Monte Carlo simulation of varying doses of intravenous metronidazole. Diag Micro and Infect Dis 55:303-309, 2006

Rooney AP, Swezey, JL, Friedman R, Hecht DW and Maddox CW. Analyses of Core Housekeeping and Virulence Genes Reveals Cryptic Lineages of Clostridium perfringens Genetics 172(4):2081-92,
2006.

Hecht  DW.  Anaerobes:  Antibiotic  resistance,  Clinical  Significance,  and  the  role  of  susceptibility testing. Anaerobe 12:115-122, 2006.

Vedantam  G,  Knopf  S,  Hecht  DW.  (2006).  Bacteroides  fragilis  mobilizable  transposon  Tn5520 requires a 71 base pair origin of transfer sequence and a single mobilization  protein for relaxosome formation during conjugation. Molecular Microbiology 59:288-300.

Rooney AP, Swezey, JL, Friedman R, Hecht DW and Maddox CW. (2006) Analyses of  Core
Housekeeping and Virulence Genes Reveals Cryptic Lineages of Clostridium perfringens.  Genetics
172(4):2081-92.

Hecht   DW.   (2006).   Anaerobes:   Antibiotic   resistance,   Clinical   Significance,   and   the   role   of susceptibility testing. Anaerobe 12:115-122.

Finegold SM, Song Y, Liu C, Hecht DW, Summanen P, Kononen E, Allen SD. (2005). Clostridium clostridioforme,  a mixed breed with a big bite. European  J Microbiology.   European  J Microbiology and Infect Dis 24:319-24.

Hecht, DW.(2004). Prevalence of antibiotic resistance in anaerobic bacteria: worrisome developments. Clin Infect Dis. 39(1):92-7.

Bass K, Hecht DW. (2002). Isolation and Characterization of cLV25, a Bacteroides fragilis Chromosomal Transfer Factor Resembling Multiple Bacteroides spp Mobilizable Transposons.   J Bacteriology, 184:1895-1904.

Vedantam G, Hecht DW. (2002). Isolation and characterization of BTF-37: Chromosomal DNA captured from Bacteroides fragilis that confers self-transferability,  and expresses a pilus-like structure in Bacteroides spp. and Escherichia coli.  J Bacteriology, 184:728-738.

Vedantam, G, Novicki, TJ and Hecht DW. (1999). Tn5520, the smallest mobilizable transposon from
Bacteroides fragilis. J Bacteriol, 181:2564-2571.

Sitailo, L.A., Zagariya, A.M., Arnold, P.J., Vedantam, G., Hecht, D.W. (1998). The Bacteroides fragilis BtgA mobilization protein binds to the oriT region of pBFTM10.  J Bacteriol 180:4922-4928.

© 2009 Loyola University Chicago Stritch School of Medicine. All Rights Reserved.  Contact Us | Privacy Policy | Terms and Conditions