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Richard J. O'Callaghan

D-Index & Metrics

Biology and Biochemistry

D-Index
41
Citations
5393
World Ranking
19564
National Ranking
7972

Richard J. O'Callaghan publication distribution in Biology and Biochemistry in 2026

The chart shows the distribution of publications by all Research.com ranked scientists in the field of Biology and Biochemistry in 2026. The highlighted bar marks where Richard J. O'Callaghan sits on this spectrum.

47–56 publications: 8 scientists 57–66 publications: 35 scientists 67–76 publications: 106 scientists 77–86 publications: 231 scientists 87–96 publications: 414 scientists 97–106 publications: 546 scientists 107–116 publications: 704 scientists 117–126 publications: 849 scientists 127–136 publications: 980 scientists 137–146 publications: 942 scientists 147–156 publications: 969 scientists 157–166 publications: 950 scientists 167–176 publications: 951 scientists 177–186 publications: 915 scientists 187–196 publications: 787 scientists 197–206 publications: 841 scientists 207–216 publications: 735 scientists 217–226 publications: 709 scientists 227–236 publications: 651 scientists 237–246 publications: 605 scientists 247–256 publications: 510 scientists 257–266 publications: 524 scientists 267–276 publications: 434 scientists 277–286 publications: 418 scientists 287–296 publications: 350 scientists 297–306 publications: 363 scientists 307–316 publications: 315 scientists 317–326 publications: 296 scientists 327–336 publications: 261 scientists 337–346 publications: 240 scientists 347–356 publications: 219 scientists 357–366 publications: 197 scientists 367–376 publications: 154 scientists 377–386 publications: 161 scientists 387–396 publications: 155 scientists 397–406 publications: 145 scientists 407–416 publications: 124 scientists 417–426 publications: 112 scientists 427–436 publications: 132 scientists 437–446 publications: 116 scientists 447–456 publications: 99 scientists 457–466 publications: 81 scientists 467–476 publications: 91 scientists 477–486 publications: 80 scientists 487–496 publications: 80 scientists 497–506 publications: 60 scientists 507–516 publications: 36 scientists 517–526 publications: 46 scientists 527–536 publications: 54 scientists 537–546 publications: 44 scientists 547–556 publications: 43 scientists 557–566 publications: 43 scientists 567–576 publications: 42 scientists 577–586 publications: 25 scientists 587–596 publications: 34 scientists 597–606 publications: 23 scientists 607–616 publications: 33 scientists 617–626 publications: 31 scientists 627–636 publications: 27 scientists 637–646 publications: 25 scientists 647–656 publications: 28 scientists 657–666 publications: 34 scientists 667–676 publications: 18 scientists 677–686 publications: 16 scientists 687–696 publications: 10 scientists 697–706 publications: 12 scientists 707–716 publications: 21 scientists 717–726 publications: 12 scientists 727–736 publications: 12 scientists 737–746 publications: 10 scientists 747–756 publications: 7 scientists 757–766 publications: 13 scientists 767–776 publications: 15 scientists 777–786 publications: 13 scientists 787–796 publications: 9 scientists 797–806 publications: 9 scientists 807–816 publications: 7 scientists 817–826 publications: 4 scientists 827–836 publications: 9 scientists 837–846 publications: 7 scientists 847–856 publications: 3 scientists 857–866 publications: 5 scientists 867–876 publications: 5 scientists 877–886 publications: 11 scientists 887–896 publications: 3 scientists 897–906 publications: 4 scientists 907–916 publications: 7 scientists 917–926 publications: 5 scientists 927–936 publications: 6 scientists 937–946 publications: 6 scientists 947–956 publications: 3 scientists 957–966 publications: 7 scientists 967–976 publications: 2 scientists 977–986 publications: 2 scientists 987–996 publications: 1 scientists 997–1,006 publications: 5 scientists 1,007–1,016 publications: 2 scientists 1,017–1,026 publications: 2 scientists 1,027 publications: 1 scientists 1,028+ publications: 100 scientists
47 publications 1,028+

This scientist: 154 publications — 29th percentile

29% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 1,028 publications or more.

Richard J. O'Callaghan D-index placement in Biology and Biochemistry in 2026

The chart shows the D-index (discipline H-index) distribution of Biology and Biochemistry scientists ranked by Research.com in 2026. The highlighted bar marks where Richard J. O'Callaghan sits on this spectrum.

40–41 D-Index: 80 scientists 42–43 D-Index: 183 scientists 44–45 D-Index: 317 scientists 46–47 D-Index: 504 scientists 48–49 D-Index: 718 scientists 50–51 D-Index: 900 scientists 52–53 D-Index: 1,026 scientists 54–55 D-Index: 1,150 scientists 56–57 D-Index: 1,236 scientists 58–59 D-Index: 1,253 scientists 60–61 D-Index: 1,163 scientists 62–63 D-Index: 1,131 scientists 64–65 D-Index: 1,032 scientists 66–67 D-Index: 897 scientists 68–69 D-Index: 814 scientists 70–71 D-Index: 715 scientists 72–73 D-Index: 709 scientists 74–75 D-Index: 596 scientists 76–77 D-Index: 512 scientists 78–79 D-Index: 473 scientists 80–81 D-Index: 412 scientists 82–83 D-Index: 373 scientists 84–85 D-Index: 358 scientists 86–87 D-Index: 285 scientists 88–89 D-Index: 273 scientists 90–91 D-Index: 227 scientists 92–93 D-Index: 208 scientists 94–95 D-Index: 193 scientists 96–97 D-Index: 153 scientists 98–99 D-Index: 157 scientists 100–101 D-Index: 148 scientists 102–103 D-Index: 120 scientists 104–105 D-Index: 113 scientists 106–107 D-Index: 100 scientists 108–109 D-Index: 86 scientists 110–111 D-Index: 67 scientists 112–113 D-Index: 72 scientists 114–115 D-Index: 73 scientists 116–117 D-Index: 64 scientists 118–119 D-Index: 53 scientists 120–121 D-Index: 60 scientists 122–123 D-Index: 54 scientists 124–125 D-Index: 43 scientists 126–127 D-Index: 38 scientists 128–129 D-Index: 49 scientists 130–131 D-Index: 26 scientists 132–133 D-Index: 18 scientists 134–135 D-Index: 23 scientists 136–137 D-Index: 32 scientists 138–139 D-Index: 32 scientists 140–141 D-Index: 27 scientists 142–143 D-Index: 19 scientists 144–145 D-Index: 22 scientists 146–147 D-Index: 12 scientists 148–149 D-Index: 16 scientists 150–151 D-Index: 14 scientists 152–153 D-Index: 10 scientists 154–155 D-Index: 13 scientists 156–157 D-Index: 10 scientists 158–159 D-Index: 7 scientists 160–161 D-Index: 9 scientists 162–163 D-Index: 13 scientists 164–165 D-Index: 4 scientists 166 D-Index: 4 scientists 167+ D-Index: 98 scientists
40 D-Index 167+

This scientist: 41 D-Index — 1st percentile

1% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 167 D-Index or more.

Overview

Richard J. O'Callaghan is affiliated with the University of Mississippi Medical Center in the United States. Their research primarily spans the fields of Medicine and Biochemistry, Genetics, and Molecular Biology, with a focus on ophthalmology, infectious diseases, and molecular biology subfields.

The scientist's work concentrates on specific topics including:

  • Ocular Infections and Treatments
  • Antimicrobial Resistance in Staphylococcus
  • Bacterial biofilms and quorum sensing

One notable recent publication by Richard J. O'Callaghan is titled Correlation of Staphylococcus Epidermidis Phenotype and Its Corneal Virulence, published in 2020 in the journal Current Eye Research. This publication has received citations reflecting engagement within the academic community.

Frequent collaborators in the scientist's research endeavors include:

  • Armando R. Caballero
  • Aihua Tang
  • Michael A. Bierdeman
  • Mary E. Marquart

Richard J. O'Callaghan's research contributions have appeared primarily in Current Eye Research, which is a platform for disseminating findings related to ocular health and disease.

Best Publications

  • Protease IV, a Unique Extracellular Protease and Virulence Factor from Pseudomonas aeruginosa

    Lee S. Engel;James M. Hill;Armando R. Caballero;Linda C. Green

  • Specific roles of alpha-toxin and beta-toxin during Staphylococcus aureus corneal infection.

    R J O'Callaghan;M C Callegan;J M Moreau;L C Green

  • Pseudomonas aeruginosa protease IV enzyme assays and comparison to other Pseudomonas proteases.

    Armando R. Caballero;Judy M. Moreau;Lee S. Engel;Mary E. Marquart

  • Corneal virulence of Staphylococcus aureus: roles of alpha-toxin and protein A in pathogenesis.

    M C Callegan;L S Engel;J M Hill;R J O'Callaghan

  • Pseudomonas aeruginosa protease IV degrades surfactant proteins and inhibits surfactant host defense and biophysical functions

    Jaret L. Malloy;Ruud A. W. Veldhuizen;Brett A. Thibodeaux;Richard J. O'Callaghan

  • Pseudomonas keratitis. The role of an uncharacterized exoprotein, protease IV, in corneal virulence.

    R J O'Callaghan;L S Engel;J A Hobden;M C Callegan

  • Pseudomonas aeruginosa protease IV produces corneal damage and contributes to bacterial virulence.

    L S Engel;J M Hill;J M Moreau;L C Green

  • Stages in phage R17 infection. VI. Injection of A protein and RNA into the host cell.

    P.M. Krahn;R.J. O'Callaghan;W. Paranchych

  • The Pathogenesis of Staphylococcus aureus Eye Infections

    Richard J O'Callaghan

  • Prevention of diseases caused by Staphylococcus aureus using the peptide RIP

    Naomi Balaban;L.Vincent Collins;James S Cullor;Emma B Hume

  • The Role of Pneumolysin in Ocular Infections with Streptococcus Pneumoniae

    Mary K. Johnson;Jeffery A. Hobden;Michael Hagenah;Richard J. O'callaghan

  • Identification of a novel secreted protease from Pseudomonas aeruginosa that causes corneal erosions.

    Mary E Marquart;Armando R Caballero;Mullika Chomnawang;Brett A Thibodeaux

  • Effectiveness of Ciprofloxacin, Levofloxacin, or Moxifloxacin for Treatment of Experimental Staphylococcus aureus Keratitis

    Joseph J. Dajcs;Brett A. Thibodeaux;Mary E. Marquart;Dalia O. Girgis

  • Quantitation of herpes simplex virus type 1 DNA and latency-associated transcripts in rabbit trigeminal ganglia demonstrates a stable reservoir of viral nucleic acids during latency.

    J M Hill;B M Gebhardt;R Wen;A M Bouterie

  • Human antibody to influenza C virus: its age-related distribution and distinction from receptor analogs.

    R J O'Callaghan;R S Gohd;D D Labat

  • Corneal virulence of Staphylococcus aureus in an experimental model of keratitis.

    Joseph J. Dajcs;Brett A. Thibodeaux;Dalia O. Girgis;Richard J. O'Callaghan

  • Infectious Keratitis: Secreted Bacterial Proteins That Mediate Corneal Damage

    Mary E. Marquart;Richard J. O'Callaghan

  • Immunization with alpha-toxin toxoid protects the cornea against tissue damage during experimental Staphylococcus aureus keratitis.

    Emma B. H. Hume;Joseph J. Dajcs;Judy M. Moreau;Richard J. O'Callaghan

  • Iontophoresis of tobramycin for the treatment of experimental Pseudomonas keratitis in the rabbit.

    David S. Rootman;Jeffery A. Hobden;Julie A. Jantzen;José R. Gonzalez

  • Immunity to lysostaphin and its therapeutic value for ocular MRSA infections in the rabbit.

    Joseph J Dajcs;Brett A Thibodeaux;Dalia O Girgis;Megan D Shaffer

Frequent Co-Authors

James M. Hill
James M. Hill Louisiana State University
Herbert E. Kaufman
Herbert E. Kaufman Louisiana State University
Larry S. McDaniel
Larry S. McDaniel University of Mississippi Medical Center
Timothy J. Foster
Timothy J. Foster Campden BRI (United Kingdom)
Jan Tommassen
Jan Tommassen Utrecht University
Mark D. P. Willcox
Mark D. P. Willcox University of New South Wales
Timothy J. Mitchell
Timothy J. Mitchell University of Birmingham
Reuben Ramphal
Reuben Ramphal University of Florida
Mark E. Shirtliff
Mark E. Shirtliff University of Maryland, Baltimore
Andrej Tarkowski
Andrej Tarkowski Sahlgrenska University Hospital

External Links

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Best Scientists Citing Richard J. O'Callaghan

Mark D. P. Willcox

Mark D. P. Willcox

University of New South Wales

Publications: 45

James M. Hill

James M. Hill

Louisiana State University

Publications: 22

David J. Evans

David J. Evans

Touro University California

Publications: 21

Linda D. Hazlett

Linda D. Hazlett

Wayne State University

Publications: 20

Suzanne M. J. Fleiszig

Suzanne M. J. Fleiszig

University of California, Berkeley

Publications: 18

Michael S. Gilmore

Michael S. Gilmore

Harvard Medical School

Publications: 16

Xuming Deng

Xuming Deng

Jilin University

Publications: 13

Robert M. Q. Shanks

Robert M. Q. Shanks

University of Pittsburgh

Publications: 12

Pyong Woo Park

Pyong Woo Park

Boston Children's Hospital

Publications: 11

Liangfang Zhang

Liangfang Zhang

University of California, San Diego

Publications: 11

Dennis E. Ohman

Dennis E. Ohman

Virginia Commonwealth University Medical Center

Publications: 9

Andrea Giacometti

Andrea Giacometti

Ca Foscari University of Venice

Publications: 9

Oscar Cirioni

Oscar Cirioni

Marche Polytechnic University

Publications: 9

Michael Givskov

Michael Givskov

University of Copenhagen

Publications: 9

Timothy J. Mitchell

Timothy J. Mitchell

University of Birmingham

Publications: 9

Timothy J. Foster

Timothy J. Foster

Campden BRI (United Kingdom)

Publications: 9

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