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Pathogens (Basel, Switzerland) Apr 2024Bovine respiratory disease (BRD) is the leading cause of mortality and antimicrobial drug (AMD) use in weaned dairy heifers. Limited information is available regarding...
Bovine respiratory disease (BRD) is the leading cause of mortality and antimicrobial drug (AMD) use in weaned dairy heifers. Limited information is available regarding antimicrobial resistance (AMR) in respiratory bacteria in this population. This study determined AMR gene presence in 326 respiratory isolates (, , and ) from weaned dairy heifers using whole genome sequencing. Concordance between AMR genotype and phenotype was determined. Twenty-six AMR genes for 8 broad classes of AMD were identified. The most prevalent, medically important AMD classes used in calf rearing, to which these genes predict AMR among study isolates were tetracycline (95%), aminoglycoside (94%), sulfonamide (94%), beta-lactam (77%), phenicol (50%), and macrolide (44%). The co-occurrence of AMR genes within an isolate was common; the largest cluster of gene co-occurrence encodes AMR to phenicol, macrolide, elfamycin, β-lactam (cephalosporin, penam cephamycin), aminoglycoside, tetracycline, and sulfonamide class AMD. Concordance between genotype and phenotype varied (Matthew's Correlation Coefficient ranged from -0.57 to 1) by bacterial species, gene, and AMD tested, and was particularly poor for fluoroquinolones (no AMR genes detected) and ceftiofur (no phenotypic AMR classified while AMR genes present). These findings suggest a high genetic potential for AMR in weaned dairy heifers; preventing BRD and decreasing AMD reliance may be important in this population.
PubMed: 38668255
DOI: 10.3390/pathogens13040300 -
Animals : An Open Access Journal From... Jan 2024(1) Background: () is an opportunistic pathogen and is mainly associated with respiratory diseases in cattle, sheep, and goats. (2) Methods: In this study, a mouse...
(1) Background: () is an opportunistic pathogen and is mainly associated with respiratory diseases in cattle, sheep, and goats. (2) Methods: In this study, a mouse infection model was established using a strain isolated from goats. Histopathological observations were conducted on various organs of the mice, and bacterial load determination and RNA-seq analysis were specifically performed on the spleens of the mice. (3) Results: The findings of this study suggest that chemokines, potentially present in the spleen of mice following a challenge, may induce the migration of leukocytes to the spleen and suppress the release of pro-inflammatory factors through a negative feedback regulation mechanism. Additionally, an interesting observation was made regarding the potential of hematopoietic stem/progenitor cells congregating in the spleen to differentiate into immune cells, which could potentially collaborate with leukocytes in their efforts to counteract invasion. (4) Conclusions: This study revealed the immune regulation mechanism induced by in the mouse spleen, providing valuable insights into host-pathogen interactions and offering a theoretical basis for the prevention, control, and treatment of mannheimiosis.
PubMed: 38275777
DOI: 10.3390/ani14020317 -
PloS One 2023Respiratory disease is responsible for dramatic population declines in bighorn sheep (Ovis canadensis), and respiratory pathogen diagnostics contribute to the management...
Assessing shared respiratory pathogens between domestic (Ovis aries) and bighorn (Ovis canadensis) sheep; methods for multiplex PCR, amplicon sequencing, and bioinformatics to characterize respiratory flora.
Respiratory disease is responsible for dramatic population declines in bighorn sheep (Ovis canadensis), and respiratory pathogen diagnostics contribute to the management of bighorn populations. To create a comprehensive and consistent approach to bighorn sheep respiratory diagnostics, we created a culture-independent assay to detect and strain type Mannheimia haemolytica, Bibersteinia trehalosi, Pasteurella multocida, and Mycoplasma ovipneumoniae. The assay also detects and characterizes the Pasteurellaceae leukotoxin A gene, and broadly assesses the bacterial composition of each sample based on 16S rRNA sequences. The assay is based on a three-step approach: 1) Multiplex PCR to amplify targets including eight loci for each bacterial species, the Pasteurellaceae lktA gene, and the 16S rRNA gene 2) Library preparation, barcoding, and short-read Illumina sequencing to determine the genetic sequences of each target, and 3) Bioinformatics in the form of automated software to analyze genetic sequences. The assay was designed to assess shared pathogens between domestic and bighorn sheep, but could be useful for many applications in bighorn sheep respiratory disease research and management.
Topics: Animals; Sheep; Sheep, Bighorn; Sheep, Domestic; Multiplex Polymerase Chain Reaction; RNA, Ribosomal, 16S; Sheep Diseases; Mannheimia haemolytica; Respiratory Tract Diseases; Computational Biology
PubMed: 37856492
DOI: 10.1371/journal.pone.0293062 -
Antibiotics (Basel, Switzerland) Jan 2024Antimicrobial resistance (AMR) is considered one of the greatest threats to both human and animal health. Efforts to address AMR include implementing antimicrobial...
Antimicrobial resistance (AMR) is considered one of the greatest threats to both human and animal health. Efforts to address AMR include implementing antimicrobial stewardship programs and introducing alternative treatment options. Nevertheless, effective treatment of infectious diseases caused by bacteria will still require the identification and development of new antimicrobial agents. Eight different natural products were tested for antimicrobial activity against seven pathogenic bacterial species ( sp., sp., sp., sp., sp., sp., sp.). In a first pre-screening, most compounds (five out of eight) inhibited bacterial growth only at high concentrations, but three natural products (celastramycin A [CA], closthioamide [CT], maduranic acid [MA]) displayed activity at concentrations <2 µg/mL against sp. and two of them (CA and CT) also against sp. Those results were confirmed by testing a larger collection of isolates encompassing 64 and 56 field isolates originating from pigs or cattle, which yielded MIC values of 0.5, 0.5, and 2 µg/mL against and 0.5, 4, and >16 µg/mL against for CA, CT, and MA, respectively. CA, CT, and MA exhibited higher MIC and MIC values against isolates with a known AMR phenotype against commonly used therapeutic antimicrobial agents than against isolates with unknown AMR profiles. This study demonstrates the importance of whole-cell antibacterial screening of natural products to identify promising scaffolds with broad- or narrow-spectrum antimicrobial activity against important Gram-negative veterinary pathogens with zoonotic potential.
PubMed: 38391521
DOI: 10.3390/antibiotics13020135 -
Canadian Journal of Veterinary Research... Jul 2023group (SB group) calves were fed 2.0 × 10 CFU/day of in milk replacer after 2 wk of age. All calves received inactivated vaccine for , and at 3 wk of age and 3 wk...
group (SB group) calves were fed 2.0 × 10 CFU/day of in milk replacer after 2 wk of age. All calves received inactivated vaccine for , and at 3 wk of age and 3 wk later. After vaccination, the SB group calves showed significantly higher (mean difference: 1.56-fold) antibody titer against than the control group. The number of calves with the antibody titer above the cut-off value for of the SB group was significantly higher than that of the control, and the percentage was twice as high. In addition, the mRNA transcription of and in peripheral blood mononuclear cells at the booster of the SB group was significantly higher than those of the control. In conclusion, may have positively affected immune responses to the inactivated multi-bacterial vaccine in young calves in the field.
Topics: Cattle; Animals; Saccharomyces boulardii; Vaccines, Inactivated; Leukocytes, Mononuclear; Bacteria; Mannheimia haemolytica; Saccharomyces cerevisiae; Cattle Diseases; Dietary Supplements; Bacterial Vaccines
PubMed: 37397640
DOI: No ID Found -
Journal of Dairy Science Dec 2023The high degree of commingling and accumulation of stressors during and after transport makes prevention of bovine respiratory disease (BRD) extremely challenging in the...
The high degree of commingling and accumulation of stressors during and after transport makes prevention of bovine respiratory disease (BRD) extremely challenging in the veal and dairy beef industry. Upon arrival, vaccination for agents involved in BRD is practically most achievable, but its efficacy under such conditions in dairy veal calves is unknown. Given the high prevalence of subclinical pneumonia in these settings, the primary objective of the present study was to determine the effect of 2 vaccination protocols administered upon arrival against bovine respiratory syncytial virus (BRSV), bovine parainfluenza type 3 virus (BPI-3), and Mannheimia haemolytica on clinical BRD and lung ultrasonographic findings in dairy veal calves. In addition, the effects of vaccination on average daily live weight gain and cold carcass weight were determined. In this randomized clinical trial, 443 male dairy calves were assigned to one of 3 groups: a negative, placebo-controlled group (n = 151), a vaccination group with 2 subcutaneous injections 4 wk apart with an inactivated vaccine containing BRSV, BPI-3, and M. haemolytica (parenteral [PE] group; n = 149) and a second vaccination group receiving an intranasal live-attenuated vaccine containing BRSV and BPI-3 and 2 subcutaneous vaccinations with the same inactivated vaccine as the PE vaccination group (intranasal-parenteral [IN-PE] group; n = 143). Clinical scoring and quick thoracic ultrasonography (qTUS) were performed on all calves on arrival (wk 0), at the peak of respiratory disease (outbreak; wk 1), at the end of the first antimicrobial group treatment (wk 3), and at a long-term evaluation point (wk 10). Culture and nanopore sequencing on nonendoscopic bronchoalveolar lavage (nBAL) samples were used to identify pathogens involved in the outbreak. Upon arrival, 15.1% of the calves had lung consolidation ≥1cm and incidence quickly rose to 42.8% during the outbreak. In both the PE and IN-PE group, the odds of pneumonia in wk 10 were reduced by 62% (odds ratio [OR] = 0.38; 95% confidence interval [CI] = 0.23-0.64) and 41% (OR = 0.59; 95% CI = 0.37-0.96), respectively. Short-term cure rate (50.3%), as determined immediately after the first group antimicrobial treatment, was not influenced by vaccination. In contrast, long-term cure rate, determined at wk 10, was affected by vaccination with higher cure in the PE group compared with the control group (69.4% vs. 51.2%; OR = 2.2; 95% CI = 1.1-5.0). Average daily gain in the first 10 wk of production was not affected by vaccination. Vaccination resulted in an increase in cold carcass weight of 3.5 and 4.3 kg in the PE (95% CI = -0.9-7.9) and IN-PE group (95% CI = -0.17-8.7), respectively. In conclusion, under the conditions of the present study, vaccination upon arrival resulted in a reduced prevalence of pneumonia at wk 10 of production, likely caused both by an improved cure rate of secondary infections and a reduced incidence of new cases between outbreak and long-term evaluation. The present protocol, using qTUS for pneumonia detection and nBAL diagnostics for pathogen identification adds a new dimension to randomized clinical trials on respiratory disease in calves.
Topics: Animals; Cattle; Male; Cattle Diseases; Vaccination; Pneumonia; Anti-Infective Agents; Ultrasonography; Vaccines, Inactivated; Respiratory Syncytial Virus, Bovine
PubMed: 37641351
DOI: 10.3168/jds.2023-23438 -
Microorganisms May 2024Pradofloxacin is the newest of the veterinary fluoroquinolones to be approved for use in animals-initially companion animals and most recently food animals. It has a...
Comparative In Vitro Killing by Pradofloxacin in Comparison to Ceftiofur, Enrofloxacin, Florfenicol, Marbofloxacin, Tildipirosin, Tilmicosin and Tulathromycin against Bovine Respiratory Bacterial Pathogens.
Pradofloxacin is the newest of the veterinary fluoroquinolones to be approved for use in animals-initially companion animals and most recently food animals. It has a broad spectrum of in vitro activity, working actively against Gram-positive/negative, atypical and some anaerobic microorganisms. It simultaneously targets DNA gyrase (topoisomerase type II) and topoisomerase type IV, suggesting a lower propensity to select for antimicrobial resistance. The purpose of this study was to determine the rate and extent of bacterial killing by pradofloxacin against bovine strains of and , in comparison with several other agents (ceftiofur, enrofloxacin, florfenicol, marbofloxacin, tildipirosin, tilmicosin and tulathromycin) using four clinically relevant drug concentrations: minimum inhibitory and mutant prevention drug concentration, maximum serum and maximum tissue drug concentrations. At the maximum serum and tissue drug concentrations, pradofloxacin killed 99.99% of cells following 5 min of drug exposure (versus growth to 76% kill rate for the other agents) and 94.1-98.6% of following 60-120 min of drug exposure (versus growth to 98.6% kill rate for the other agents). Statistically significant differences in kill rates were seen between the various drugs tested depending on drug concentration and time of sampling after drug exposure.
PubMed: 38792823
DOI: 10.3390/microorganisms12050996 -
Frontiers in Microbiology 2024Data collected from the German national resistance monitoring program GE-Vet showed slowly increasing prevalence of macrolide resistance among bovine respiratory disease...
Data collected from the German national resistance monitoring program GE-Vet showed slowly increasing prevalence of macrolide resistance among bovine respiratory disease (BRD)-associated from cattle over the last decade. The focus of this study was to analyze the genetic basis of antimicrobial resistance (AMR) and the prevalence of multidrug-resistance (MDR)-mediating integrative and conjugative elements (ICEs) in 13 German BRD-associated isolates collected between 2009 and 2020 via whole-genome sequencing. Antimicrobial susceptibility testing (AST) was performed via broth microdilution according to the recommendations of the Clinical and Laboratory Standards Institute for the macrolides erythromycin, tilmicosin, tulathromycin, gamithromycin, tildipirosin, and tylosin as well as 25 other antimicrobial agents. All isolates either had elevated MICs or were resistant to at least one of the macrolides tested. Analysis of whole-genome sequences obtained by hybrid assembly of Illumina MiSeq and Oxford Nanopore MinION reads revealed the presence of seven novel Tn-like ICEs, designated Tn, and Tn- Tn. These ICEs harbored the antimicrobial resistance genes (T), (C), (G), (Y), and in different combinations. In addition, mutational changes conferring resistance to macrolides, nalidixic acid or streptomycin, respectively, were detected among the . isolates. In addition, four isolates carried a 4,613-bp plasmid with the β-lactamase gene . The detection of the macrolide resistance genes (T), (C), and (G) together with other resistance genes on MDR-mediating ICEs in bovine may explain the occurrence of therapeutic failure when treating BRD with regularly used antimicrobial agents, such as phenicols, penicillins, tetracyclines, or macrolides. Finally, pathogen identification and subsequent AST is essential to ensure the efficacy of the antimicrobial agents applied to control BRD in cattle.
PubMed: 38495516
DOI: 10.3389/fmicb.2024.1356208 -
American Journal of Veterinary Research May 2024To determine the efficacy of primary or booster intranasal vaccination of beef steers on clinical protection and pathogen detection following simultaneous challenge with...
Intranasal booster vaccination of beef steers reduces clinical signs following experimental coinfection with BRSV and BHV-1 without reducing shedding of BRD-associated bacteria.
OBJECTIVE
To determine the efficacy of primary or booster intranasal vaccination of beef steers on clinical protection and pathogen detection following simultaneous challenge with bovine respiratory syncytial virus and bovine herpes virus 1.
METHODS
30 beef steers were randomly allocated to 3 different treatment groups starting at 2 months of age. Group A (n = 10) was administered a single dose of a parenteral modified-live vaccine and was moved to a separate pasture. Groups B (n = 10) and C (10) remained unvaccinated. At 6 months of age, all steers were weaned and transported. Subsequently, groups A and B received a single dose of an intranasal modified-live vaccine vaccine while group C remained unvaccinated. Group C was housed separately until challenge. Two days following vaccination, all steers were challenged with bovine respiratory syncytial virus and bovine herpes virus 1 and housed in a single pen. Clinical and antibody response outcomes and the presence of nasal pathogens were evaluated.
RESULTS
The odds of clinical disease were lower in group A compared with group C on day 7 postchallenge; however, antibody responses and pathogen detection were not significantly different between groups before and following viral challenge. All calves remained negative for Histophilus somni and Mycoplasma bovis; however, significantly greater loads of Mannheimia haemolytica and Pasteurella multocida were detected on day 7 postchallenge compared with day -2 prechallenge.
CLINICAL RELEVANCE
Intranasal booster vaccination of beef steers at 6 months of age reduced clinical disease early after viral challenge. Weaning, transport, and viral infection promoted increased detection rates of M haemolytica and P multocida regardless of vaccination status.
Topics: Animals; Cattle; Herpesvirus 1, Bovine; Male; Administration, Intranasal; Respiratory Syncytial Virus, Bovine; Immunization, Secondary; Coinfection; Respiratory Syncytial Virus Infections; Infectious Bovine Rhinotracheitis; Cattle Diseases; Viral Vaccines; Bacterial Shedding; Antibodies, Viral; Herpesviridae Infections; Random Allocation; Vaccination
PubMed: 38422620
DOI: 10.2460/ajvr.23.11.0266 -
Frontiers in Microbiology 2024Bovine respiratory disease (BRD) is one of the most important animal health problems in the beef industry. While bacterial culture and antimicrobial susceptibility...
Bacterial enrichment prior to third-generation metagenomic sequencing improves detection of BRD pathogens and genetic determinants of antimicrobial resistance in feedlot cattle.
INTRODUCTION
Bovine respiratory disease (BRD) is one of the most important animal health problems in the beef industry. While bacterial culture and antimicrobial susceptibility testing have been used for diagnostic testing, the common practice of examining one isolate per species does not fully reflect the bacterial population in the sample. In contrast, a recent study with metagenomic sequencing of nasal swabs from feedlot cattle is promising in terms of bacterial pathogen identification and detection of antimicrobial resistance genes (ARGs). However, the sensitivity of metagenomic sequencing was impeded by the high proportion of host biomass in the nasal swab samples.
METHODS
This pilot study employed a non-selective bacterial enrichment step before nucleic acid extraction to increase the relative proportion of bacterial DNA for sequencing.
RESULTS
Non-selective bacterial enrichment increased the proportion of bacteria relative to host sequence data, allowing increased detection of BRD pathogens compared with unenriched samples. This process also allowed for enhanced detection of ARGs with species-level resolution, including detection of ARGs for bacterial species of interest that were not targeted for culture and susceptibility testing. The long-read sequencing approach enabled ARG detection on individual bacterial reads without the need for assembly. Metagenomics following non-selective bacterial enrichment resulted in substantial agreement for four of six comparisons with culture for respiratory bacteria and substantial or better correlation with qPCR. Comparison between isolate susceptibility results and detection of ARGs was best for macrolide ARGs in reads but was also substantial for sulfonamide ARGs within and reads and tetracycline ARGs in reads.
DISCUSSION
By increasing the proportion of bacterial DNA relative to host DNA through non-selective enrichment, we demonstrated a corresponding increase in the proportion of sequencing data identifying BRD-associated pathogens and ARGs in deep nasopharyngeal swabs from feedlot cattle using long-read metagenomic sequencing. This method shows promise as a detection strategy for BRD pathogens and ARGs and strikes a balance between processing time, input costs, and generation of on-target data. This approach could serve as a valuable tool to inform antimicrobial management for BRD and support antimicrobial stewardship.
PubMed: 38779502
DOI: 10.3389/fmicb.2024.1386319