Effects of cecropin B transgene expression on Mannheimia haemolytica serotype 1 colonization of the nasal mucosa of calves

Boudreaux, Charles M.; Corstvet, Richard E.; Cooper, Richard K.; Enright, Frederick M.

doi:10.2460/ajvr.2005.66.1922

Cited by 3 publications

(2 citation statements)

References 38 publications

(37 reference statements)

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“…Cercropin is an antimicrobial peptide from insects that, when delivered by vector to bovine mucosa, reduces colonization by Mannheimia haemoyltica. 9 Bovine neutrophils have numerous alpha defensins as well; however, these are produced in neutrophils and are present in the ASL only after neutrophil recruitment and degranulation. Cathelicidin antimicrobial peptides are also produced in neutrophils and can be released by lung epithelia; however, epithelial expression is apparently low and limited.…”

Section: Air Surface Liquidmentioning

confidence: 99%

Innate Immunology of Bovine Respiratory Disease

Ackermann

Derscheid

Roth

2010

Veterinary Clinics of North America: Food Animal Practice

106

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There are a variety of factors and conditions that predispose cattle to pneumonia. Cattle have anatomic and cellular differences from humans and other species and are managed in groups/herds, all of which can increase susceptibility to microbial pathogens. This article highlights the basic innate immune response of the respiratory tract and newer developments in the understanding of adaptive immune responses of the bovine respiratory tract, placing special emphasis on features unique to cattle.

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Section: Air Surface Liquidmentioning

confidence: 99%

Innate Immunology of Bovine Respiratory Disease

Ackermann

Derscheid

Roth

2010

Veterinary Clinics of North America: Food Animal Practice

106

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“…The resultant transgenic organisms, expressing AMP genes, exhibit enhanced resistance to bacterial infection (5,16,30,36). Our laboratory has successfully enhanced the innate immune defense of fish through the genomic integration of a cecropin B transgene (30).…”

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confidence: 99%

Inducible Resistance of Fish Bacterial Pathogens to the Antimicrobial Peptide Cecropin B

Sallum

Chen

2008

Antimicrob Agents Chemother

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Cecropin B is a cationic antimicrobial peptide originally isolated from the diapausing pupae of the giant silk moth, Hylphora cecropia. Cecropin B elicits its antimicrobial effects through disruption of the anionic cell membranes of gram-negative bacteria. Previous work by our laboratory demonstrated that a constitutively expressed cecropin B transgene conferred enhanced resistance to bacterial infection in medaka. The development of antibiotic resistance by pathogenic bacteria is a growing problem. The potential for fish bacterial pathogens to develop resistance to cecropin B was addressed in this study. Four fish bacterial pathogens were selected for the study based on their importance in aquaculture. Vibrio anguillarum, Vibrio vulnificus, and Yersinia ruckeri all exhibited inducible resistance to cecropin B. The inducible resistance of these three pathogens was correlated with reversible changes in their ultrastructures, as observed by scanning electron microscopy. V. anguillarum was demonstrated to become more adhesive to a CHSE-214 cell monolayer and to cause increased cumulative mortality in medaka following exposure to cecropin B. This work demonstrates that the resistance of fish bacterial pathogens to cecropin B is inducible and suggests that resistance to other cationic antimicrobial peptides may occur through similar means. The observed changes in ultrastructure and infectivity suggest that resistance to antimicrobial peptides is an integral part of the pathogenesis of fish gram-negative bacterial pathogens.

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Intranasal Bacterial Therapeutics Reduce Colonization by the Respiratory Pathogen Mannheimia haemolytica in Dairy Calves

et al. 2020

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Six Lactobacillus strains originating from the nasopharyngeal microbiota of cattle were previously characterized in vitro and identified as candidate bacterial therapeutics (BTs) for mitigating the bovine respiratory pathogen Mannheimia haemolytica. In the present study, these BT strains were evaluated for their potential to (i) reduce nasal colonization by M. haemolytica, (ii) modulate the nasal microbiota, and (iii) stimulate an immune response in calves experimentally challenged with M. haemolytica. Twenty-four Holstein bull calves (1 to 3 weeks old) received either an intranasal BT cocktail containing 6 Lactobacillus strains (3 × 109 CFU per strain; BT + Mh group) 24 h prior to intranasal M. haemolytica challenge (3 × 108 CFU) or no BTs prior to challenge (Mh, control group). Nasal swab, blood, and transtracheal aspiration samples were collected over the course of 16 days after BT inoculation. Counts of M. haemolytica were determined by culturing, and the nasal and tracheal microbiotas were evaluated using 16S rRNA gene sequencing. Serum cytokines (interleukin-6 [IL-6], IL-8, and IL-10) were quantified by enzyme-linked immunosorbent assay (ELISA). Administration of BT reduced nasal colonization by M. haemolytica (P = 0.02), modified the composition and diversity of the nasal microbiota, and altered interbacterial relationships among the 10 most relatively abundant genera. The BT + Mh calves also had a lower relative abundance of Mannheimia in the trachea (P < 0.01) but similar cytokine levels as Mh calves. This study demonstrated that intranasal BTs developed from the bovine nasopharyngeal Lactobacillus spp. were effective in reducing nasal colonization by M. haemolytica in dairy calves. IMPORTANCE Bovine respiratory disease (BRD) is one of the significant challenges for the modern dairy industry in North America, accounting for 23 to 47% of the total mortality among pre- and postweaned dairy heifers. Mass medication with antibiotics is a common practice to control BRD in dairy cattle. However, the emergence of multidrug-resistant BRD pathogens highlights the importance of developing alternatives to antibiotics for BRD mitigation. Using a targeted approach, we recently identified 6 Lactobacillus strains originating from the bovine respiratory microbiota as candidates to be used as bacterial therapeutics (BTs) for the mitigation of the BRD pathogen Mannheimia haemolytica. Here, we demonstrated that intranasal inoculation of the BT strains reduced nasal colonization by M. haemolytica in dairy calves experimentally challenged with this pathogen. This study, for the first time, shows the potential use of intranasal BTs as an alternative to mitigate BRD pathogens in cattle.

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Effects of cecropin B transgene expression on Mannheimia haemolytica serotype 1 colonization of the nasal mucosa of calves

Abstract: In vitro, cecropin B has an effective antibacterial activity against M. haemolytica S1 and can prevent colonization of the nasal mucosa after transfection of a vector expressing cecropin B in vivo.

Cited by 3 publications

References 38 publications

Innate Immunology of Bovine Respiratory Disease

Innate Immunology of Bovine Respiratory Disease

Inducible Resistance of Fish Bacterial Pathogens to the Antimicrobial Peptide Cecropin B

Intranasal Bacterial Therapeutics Reduce Colonization by the Respiratory Pathogen Mannheimia haemolytica in Dairy Calves

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