Antimicrobial activity of bovine bactericidal permeability–increasing protein–derived peptides against gram-negative bacteria isolated from the milk of cows with clinical mastitis

Annapoorani Chockalingam Department of Dairy and Animal Science, College of Agricultural Sciences, Pennsylvania State University, University Park, PA 16802

Search for other papers by Annapoorani Chockalingam in
Current site
Google Scholar
PubMed
Close
 PhD
,
Dante S. Zarlenga Bovine Functional Genomics Laboratory, USDA, Agricultural Research Service, Room 223, Bldg 003, Beltsville, MD 20705

Search for other papers by Dante S. Zarlenga in
Current site
Google Scholar
PubMed
Close
 PhD
, and
Douglas D. Bannerman Bovine Functional Genomics Laboratory, USDA, Agricultural Research Service, Room 223, Bldg 003, Beltsville, MD 20705

Search for other papers by Douglas D. Bannerman in
Current site
Google Scholar
PubMed
Close
 PhD

Abstract

Objective—To evaluate antimicrobial activity of bovine bactericidal permeability–increasing protein (bBPI)–derived synthetic peptides against mastitis-causing gram-negative bacteria.

Sample Population—Bacterial isolates from the milk of cows with clinical mastitis.

Procedures—3 peptides were synthesized with sequences corresponding to amino acids 65 to 99 (bBPI65–99) or 142 to 169 (bBPI142–169) or the combination of amino acids 90 to 99 and 148 to 161 (bBPI90–99,148–161) of bBPI. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these peptides against bacterial isolates from cows with mastitis were determined by use of a standardized broth microdilution assay. The ability of these peptides to retain their antimicrobial activity in serum and milk was also evaluated. Finally, bacterial lipopolysaccharide (LPS)-neutralizing activity of these peptides was assayed with the Limulus amebocyte lysate test.

Results—Of the 3 peptides tested, bBPI90–99,148–161 had the widest spectrum of antimicrobial activity, with MIC and MBC values ranging from 16 to 64 Mg/mL against Escherichia coli, Klebsiella pneumoniae, and Enterobacter spp and from 64 to 128 Mg/mL against Pseudomonas aeruginosa. None of the peptides had any growth-inhibitory effect on Serratia marcescens. The antimicrobial activity of bBPI90–99,148–161 was inhibited in milk, but preserved in serum. Finally, bBPI142–169 and bBPI90–99,148–161 completely neutralized LPS.

Conclusions and Clinical Relevance—bBPI90–99,148–161 is a potent neutralizer of the highly proinflammatory molecule bacterial LPS and has antimicrobial activity against a variety of gram-negative bacteria. The ability of bBPI90–99,148–161 to retain antimicrobial activity in serum suggests a potential therapeutic application for this peptide in the management of gram-negative septicemia.

Abstract

Objective—To evaluate antimicrobial activity of bovine bactericidal permeability–increasing protein (bBPI)–derived synthetic peptides against mastitis-causing gram-negative bacteria.

Sample Population—Bacterial isolates from the milk of cows with clinical mastitis.

Procedures—3 peptides were synthesized with sequences corresponding to amino acids 65 to 99 (bBPI65–99) or 142 to 169 (bBPI142–169) or the combination of amino acids 90 to 99 and 148 to 161 (bBPI90–99,148–161) of bBPI. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these peptides against bacterial isolates from cows with mastitis were determined by use of a standardized broth microdilution assay. The ability of these peptides to retain their antimicrobial activity in serum and milk was also evaluated. Finally, bacterial lipopolysaccharide (LPS)-neutralizing activity of these peptides was assayed with the Limulus amebocyte lysate test.

Results—Of the 3 peptides tested, bBPI90–99,148–161 had the widest spectrum of antimicrobial activity, with MIC and MBC values ranging from 16 to 64 Mg/mL against Escherichia coli, Klebsiella pneumoniae, and Enterobacter spp and from 64 to 128 Mg/mL against Pseudomonas aeruginosa. None of the peptides had any growth-inhibitory effect on Serratia marcescens. The antimicrobial activity of bBPI90–99,148–161 was inhibited in milk, but preserved in serum. Finally, bBPI142–169 and bBPI90–99,148–161 completely neutralized LPS.

Conclusions and Clinical Relevance—bBPI90–99,148–161 is a potent neutralizer of the highly proinflammatory molecule bacterial LPS and has antimicrobial activity against a variety of gram-negative bacteria. The ability of bBPI90–99,148–161 to retain antimicrobial activity in serum suggests a potential therapeutic application for this peptide in the management of gram-negative septicemia.

All Time Past Year Past 30 Days
Abstract Views 125 0 0
Full Text Views 2125 1959 1390
PDF Downloads 180 91 9
Advertisement