Cost effective control of avian diseases and food borne pathogens remains a high priority for all sectors of the poultry industry with cleansing and disinfection, vaccination and competitive ...exclusion approaches being used widely. Previous studies showed that
Bacillus subtilis PY79
hr was an effective competitive exclusion agent for use in poultry to control avian pathogenic
Escherichia coli serotype O78:K80. Here we report experiments that were undertaken to test the efficacy of
B. subtilis PY79
hr in the control of
Salmonella enterica serotype Enteritidis and
Clostridium perfringens in young chickens. To do this, 1-day-old and 20-day-old specific pathogen free (SPF) chicks were dosed with a suspension of
B. subtilis spores prior to challenge with
S. Enteritidis (S1400) and
C. perfringens, respectively. For both challenge models, a single oral inoculum of 1×10
9 spores given 24
h prior to challenge was sufficient to suppress colonisation and persistence of both
S. Enteritidis and
C. perfringens. In particular, the faecal shedding of
S. Enteritidis, as measured by a semi-quantitative cloacal swabbing technique, was reduced significantly for the 36 days duration of the experiment.
B. subtilis persisted in the intestine although with decreasing numbers over the same period. These data add further evidence that
B. subtilis spores may be effective agents in the control of avian diseases and food borne pathogens.
The development of alternatives to antibiotics is essential for the treatment of animal infections and as a measure to reduce the selective pressure on antibiotics that are critical for human ...medicine. Metal complexes have been highlighted for their antimicrobial activity against several bacterial pathogens. In particular, manganese carbonyl complexes have shown efficacy against multidrug-resistant Gram-negative pathogens, and relatively low cytotoxicity against avian macrophages and in wax moth larval models. They are thus potential candidates for deployment against Avian Pathogenic Escherichia coli (APEC), the aetiological agent of avian colibacillosis, which results in severe animal welfare issues and financial losses worldwide. This study aimed to determine the efficacy of Mn(CO)3(tqa-κ3N)Br in Galleria mellonella and chick models of infection against APEC. The results demonstrated in vitro and in vivo antibacterial activity against all antibiotic-resistant APEC test isolates screened in the study.
•In vitro Mn(CO)3(tqa-κ3N)Br exposure results in bacterial killing at 4-hours.•Mn(CO)3(tqa-κ3N)Br reduces mortality in G. mellonella post APEC infection.•Mn(CO)3(tqa-κ3N)Br significantly reduces bacterial shedding in chicks.•Bacterial colonisation is reduced in chicks after Mn(CO)3(tqa-κ3N)Br treatment.
Abstract Background One Health (OH) is defined as a unifying approach aiming to sustainably balance and optimise the health of people, animals and the ecosystem. It recognises that the health of ...humans, animals (both domestic and wild), plants and the wider ecosystem are both interdependent and linked. As a concept, it aims to address complex problems requiring input from multiple disciplines. Suitable issues for OH approaches typically include global issues which can widely impact not only the health of humans and animals, but also have a significant environmental impact. Examples include emerging zoonotic diseases and antimicrobial resistance (AMR). Interpretations and use of the term OH differ in the literature and have the potential to dilute its impact. The meaning of OH among the research community has evolved over time. Here, we collate the OH relevant literature from the last two decades, identifying major themes and trends and considering how OH has been embraced differently across various geographical regions. Methods and results Bibliographic databases were searched using the term “One Health” AND (“Veterinary” OR “Animal”) AND (“Medicine” OR “Human”) AND (“Environment” OR “Ecosystem”) during the period between 1980 and 2022. Data analysis and narrative synthesis identified themes, similarities, and differences within literature. Web of Science and PubMed returned 948 and 1250 results for the period mentioned above. The predominant literature focused on human health, with veterinary health second, although often to benefit human health. It was found that OH is often utilised as a public health approach, generally towards the end of disease surveillance and control. Interestingly, while authors from low- and middle-income countries were well-represented within studies using the term OH, they were less well-represented as corresponding authors. Conclusions The predominant focus of the literature was on human and veterinary health, implying OH approach is human-orientated, despite its suggestion that all domains share a common ‘health’. Potential improvement to OH could be achieved through greater incorporation of the environmental and social sciences for a more encompassing approach.
The genus
has been extensively studied and it is known to encompass a range of commensal and pathogenic bacteria that primarily inhabit the gastrointestinal tracts of warm-blooded vertebrates. ...However, the presence of
as a model organism and potential pathogen has diverted attention away from commensal strains and other species in the genus. To investigate the diversity of
in healthy chickens, we collected fecal samples from antibiotic-free Lohmann Brown layer hens and determined the genome sequences of 100 isolates, 81 of which were indistinguishable at the HC0 level of the Hierarchical Clustering of Core Genome Multi-Locus Sequence Typing scheme. Despite initial selection on CHROMagar Orientation medium, which is considered selective for
,
phylotyping and core genome single nucleotide polymorphism analysis revealed the presence of at least one representative of all major clades of
, except for
, and
phylogroup B2 and cryptic clade I. The most frequent phylogenomic groups were
phylogroups A and B1 and
(clades III and IV). We compiled a collection of reference strains isolated from avian sources (predominantly chicken), representing every
phylogroup and species, and used it to confirm the phylogeny and diversity of our isolates. Overall, the isolates carried low numbers of the virulence and antibiotic resistance genes typically seen in avian pathogenic
. Notably, the clades not recovered are ones that have been most strongly associated with virulence by other studies.
Brachyspira pilosicoli is a zoonotic bacterium that can cause intestinal spirochaetosis (IS) in avian species (AIS), pigs (PIS) and humans (HIS). In the absence of vaccines to prevent infections, we ...used genome-based reverse vaccinology (RV) to identify putative B. pilosicoli vaccine candidates. Genome sequence of B. pilosicoli strain B2904, an AIS isolate, was analysed with PSORTb3, CELLO, SOSUIGramN, LipoP, SignalP-5.0, TMHMM, BLAST 2.12.0+, PDB database, SEED Viewer, eggNOG-mapper, UniProt, VaxiJen and Vaxign2, and Tblastn to generate a RV list of putative vaccine candidates. We also generated a linear B-cell chimera antigen using Blast-p, Emini Surface Accessibility Prediction, ABCpred, Expasy ProtParam and PepCalc programs. RV defined a list of 162 proteins containing 48 Outer Membrane (OM), 27 OM/Extracellular, 27 Extracellular, 4 Periplasm, 2 Surface, 2 Cytoplasm and 52 Unknown proteins. The list was characterised by an abundance of SPII lipoproteins. We found that genes encoding amino acid sequences of 146/162 (90%) proteins were present in 19 other B. pilosicoli genomes. A linear B-cell chimera antigen was generated from the amino acid sequences of 18 OM and Extracellular proteins. Our contemporary RV study represents a starting point for a comprehensive vaccine development strategy for preventing intestinal spirochaetosis.
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•No vaccines are licensed for preventing intestinal spirochaetosis caused by Brachyspira pilosicoli.•We identified candidate vaccine antigens using in silico reverse vaccinology.•We developed a B-cell chimera antigen from linear epitopes of 18 outer membrane and extracellular proteins.
Background
Despite considerable recent reductions in antimicrobial use, the UK gamebird industry continues to struggle with production diseases during the rearing season, necessitating significant ...antibiotic use. This observational study investigated the presence of genes conferring resistance to β‐lactam antibiotics within industry‐reared pheasants and red‐legged partridges in the UK.
Methods
DNA was extracted from 60 pooled caecal samples collected from gamebirds at routine postmortem examinations during the rearing season. Genes encoding extended‐spectrum β‐lactamases (ESBL) were detected by PCR and the corresponding alleles were determined.
Results
Over half (53%) of the samples harboured genes encoding blaTEM resistance, with blaSHV identified in 20% of samples. The blaTEM gene was more common on sites with higher antibiotic use, whereas blaSHV was predominantly found in birds younger than 5 weeks. Genotyping of the identified resistance genes revealed the presence of blaTEM‐1, blaSHV‐1 and blaSHV‐11 alleles.
Limitations
This was a small‐scale study conducted at four sites in southern England.
Conclusion
This is the first report of the presence of ESBL genes in gamebirds, highlighting the need for further research into antimicrobial resistance in UK gamebirds.
Summary
The ability of an isogenic set of mutants of Salmonella enterica serovar Typhimurium L354 (SL1344) with defined deletions in genes encoding components of tripartite efflux pumps, including ...acrB, acrD, acrF and tolC, to colonize chickens was determined in competition with L354. In addition, the ability of L354 and each mutant to adhere to, and invade, human embryonic intestine cells and mouse monocyte macrophages was determined in vitro. The tolC and acrB knockout mutants were hyper‐susceptible to a range of antibiotics, dyes and detergents; the tolC mutant was also more susceptible to acid pH and bile and grew more slowly than L354. Complementation of either gene ablated the phenotype. The tolC mutant poorly adhered to both cell types in vitro and was unable to invade macrophages. The acrB mutant adhered, but did not invade macrophages. In vivo, both the acrB mutant and the tolC mutant colonized poorly and did not persist in the avian gut, whereas the acrD and acrF mutant colonized and persisted as well as L354. These data indicate that the AcrAB–TolC system is important for the colonization of chickens by S. Typhimurium and that this system has a role in mediating adherence and uptake into target host cells.
With the advent of the global antimicrobial resistance (AMR) crisis, our arsenal of effective antibiotics is diminishing. The widespread use and misuse of antibiotics in human and veterinary ...medicine, compounded by the lack of novel classes of antibiotic in the pharmaceutical pipeline, has left a hole in our antibiotic armamentarium. Thus, alternatives to traditional antibiotics are being investigated, including two major groups of antibacterial agents, which have been extensively studied, phytochemicals and metals. Within these groups, there are several subclasses of compound/elements, including polyphenols and metal nanoparticles, which could be used to complement traditional antibiotics, either to increase their potency or extend their spectrum of activity. Alone or in combination, these antibacterial agents have been shown to be effective against a vast array of human and animal bacterial pathogens, including those resistant to licensed antibacterials. These alternative antibacterial agents could be a key element in our fight against AMR and provide desperately needed options, to veterinary and medical clinicians alike.
The rapid rise in the health burden associated with chronic wounds is of great concern to policymakers, academia, and industry. This could be attributed to the devastating implications of this ...condition, and specifically, chronic wounds which have been linked to invasive microbial infections affecting patients' quality of life. Unfortunately, antibiotics are not always helpful due to their poor penetration of bacterial biofilms and the emergence of antimicrobial resistance. Hence, there is an urgent need to explore antibiotics-free compounds/formulations with proven or potential antimicrobial, anti-inflammatory, antioxidant, and wound healing efficacy. The mechanism of antibiotics-free compounds is thought to include the disruption of the bacteria cell structure, preventing cell division, membrane porins, motility, and the formation of a biofilm. Furthermore, some of these compounds foster tissue regeneration by modulating growth factor expression. In this review article, the focus is placed on a number of non-antibiotic compounds possessing some of the aforementioned pharmacological and physiological activities. Specific interest is given to
, curcumin, cinnamaldehyde, polyhexanide, retinoids, ascorbate, tocochromanols, and chitosan. These compounds (when alone or in formulation with other biologically active molecules) could be a dependable alternative in the management or prevention of chronic wounds.
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