Prophylactic phage administration reduces Salmonella Enteritidis infection in newly hatched chicks.

Salmonellosis outbreaks are global issues primarily associated with the consumption of poultry products, which may be infected with Salmonella. The use of lytic bacteriophages could be a safe and effective approach to reduce Salmonella prevalence in poultry and subsequently the incidence in humans. This study examined the value of prophylactic phage treatment on Salmonella levels in chickens and the effect of such treatment on their overall gut microbiome.

Aquatic environment drives the emergence of cell wall-deficient dormant forms in Listeria.

Stressed bacteria can enter a dormant viable but non-culturable (VBNC) state. VBNC pathogens pose an increased health risk as they are undetectable by growth-based techniques and can wake up back into a virulent state. Although widespread in bacteria, the mechanisms governing this phenotypic switch remain elusive.

Research Note: Intestinal avian defensin 2 and robustness of chicks.

Poultry production is an important agricultural sector for human food worldwide. Chicks after hatch often face health problems leading to economic losses that are deleterious for breeders. Avian defensin 2 (AvBD2) is a prominent host defense peptide of the intestinal mucosa of cecum and is involved in the resistance of poultry to bacterial pathogens.

The caecal microbiota promotes the acute inflammatory response and the loss of the intestinal barrier integrity during severe infection.

Introduction: Coccidiosis, a disease caused by intestinal apicomplexan parasites , is a threat to poultry production. is one of the most pathogenic species, frequently causing a high prevalence of opportunistic infections.

Objective: The objective of this study is to investigate the role of the microbiota in the pathogenesis of severe infection.

In ovo administration of a phage cocktail partially prevents colibacillosis in chicks.

Avian pathogenic Escherichia coli (APEC) causes colibacillosis, the main bacterial disease in poultry leading to significant economic losses worldwide. Antibiotic treatments favor the emergence of multidrug-resistant bacteria, and preventive measures are insufficient to control the disease. There is increasing interest in using the potential of bacteriophages, not only for phage therapy but also for prevention and biocontrol.

Isolation and Characterization of a Novel Phage Collection against Avian-Pathogenic .

The increase in antibiotic-resistant avian-pathogenic Escherichia coli (APEC), the causative agent of colibacillosis in poultry, warrants urgent research and the development of alternative therapies. This study describes the isolation and characterization of 19 genetically diverse, lytic coliphages, 8 of which were tested in combination for their efficacy in controlling APEC infections. Genome homology analysis revealed that the phages belong to nine different genera, one of them being a novel genus ().

Evolutionary diversification of defensins and cathelicidins in birds and primates.

Divergent evolution for more than 310 million years has resulted in an avian immune system that is complex and more compact than that of primates, sharing much of its structure and functions. Not surprisingly, well conserved ancient host defense molecules, such as defensins and cathelicidins, have diversified over time. In this review, we describe how evolution influenced the host defense peptides repertoire, its distribution, and the relationship between structure and biological functions.

Comparative Genome Analysis of Enterococcus cecorum Reveals Intercontinental Spread of a Lineage of Clinical Poultry Isolates.

Enterococcus cecorum is an emerging pathogen responsible for osteomyelitis, spondylitis, and femoral head necrosis causing animal suffering and mortality and requiring antimicrobial use in poultry. Paradoxically, E. cecorum is a common inhabitant of the intestinal microbiota of adult chickens.

Super Shedding in Enteric Pathogens: A Review.

Super shedding occurs when a small number of individuals from a given host population shed high levels of a pathogen. Beyond this general definition, various interpretations of the shedding patterns have been proposed to identify super shedders, leading to the description of the super shedding phenomenon in a wide range of pathogens, in particular enteric pathogens, which are of considerable interest. Several underlying mechanisms may explain this observation, including factors related to the environment, the gut microbiota, the pathogen itself (i.

Efficacy of passive immunization in broiler chicks via an inactivated autogenous vaccine administered to broiler breeder hens.

Avian pathogenic (APEC) cause extra-intestinal infections called colibacillosis, which is the dominant bacterial disease in broilers. To date, given the diversity of APEC strains and the need for an acceptable level of protection in day-old chicks, no satisfactory commercial vaccine is available. As part of a French nationwide project, we selected three representative strains among several hundred APEC that cause colibacillosis disease.

High genomic diversity of novel phages infecting the plant pathogen Ralstonia solanacearum, isolated in Mauritius and Reunion islands.

Bacterial wilt caused by the Ralstonia solanacearum species complex (RSSC) is among the most important plant diseases worldwide, severely affecting a high number of crops and ornamental plants in tropical regions. Only a limited number of phages infecting R. solanacearum have been isolated over the years, despite the importance of this bacterium and the associated plant disease.

The Absence of Gut Microbiota Alters the Development of the Apicomplexan Parasite .

Coccidiosis is a widespread intestinal disease of poultry caused by a parasite of the genus is one of the most virulent species that specifically colonizes the caeca, an organ which harbors a rich and complex microbiota. Our objective was to study the impact of the intestinal microbiota on parasite infection and development using an original model of germ-free broilers. We observed that germ-free chickens presented significantly much lower load of oocysts in caecal contents than conventional chickens.

Gut microbiota composition before infection determines the Salmonella super- and low-shedder phenotypes in chicken.

Heterogeneity of infection and extreme shedding patterns are common features of animal infectious diseases. Individual hosts that are super-shedders are key targets for control strategies. Nevertheless, the mechanisms associated with the emergence of super-shedders remain largely unknown.

Production of Germ-Free Fast-Growing Broilers from a Commercial Line for Microbiota Studies.

Studies of the gut microbiota contribution to the host physiology and immunocompetence are facilitated by the availability of germ-free animal models, which are considered the gold standard. Nesting birds are ideal models for the production of germ-free animals since there is no need to raise their relatives under sterile conditions. Germ-free chickens are mainly generated from specific-pathogen-free (SPF) experimental lines, which are poorly representative of commercial chicken lines.

Spread of multidrug-resistant IncHI1 plasmids carrying ESBL gene bla and metabolism operon of prebiotic oligosaccharides in commensal Escherichia coli from healthy horses, France.

The objective of the study was to identify the genetic determinants and characteristics of expanded-spectrum cephalosporin (ESC) resistance in commensal Escherichia coli from healthy horses in France in 2015. Faecal samples from 744 adult horses were screened for ESC-resistant E. coli isolates.

Virulence and antibiotic resistance profile of avian strains isolated from colibacillosis lesions in central of Algeria.

Background And Aim: Avian pathogenic cause extensive mortality in poultry flocks, leading to extensive economic losses. To date, in Algeria, little information has been available on virulence potential and antibiotics resistance of avian isolates. Therefore, the aim of this study was the characterization of virulence genes and antibiotic resistance profile of Algerian strains isolated from diseased broilers.

Avian Pathogenic (APEC) Strain-Dependent Immunomodulation of Respiratory Granulocytes and Mononuclear Phagocytes in -Reporter Transgenic Chickens.

Avian pathogenic (APEC) cause severe respiratory and systemic disease in chickens, commonly termed colibacillosis. Early immune responses after initial infection are highly important for the outcome of the infection. In this study, the early interactions between -expressing APEC strains of serotypes O1:K1:H7 and O2:K1:H5 and phagocytic cells in the lung of -reporter transgenic chickens were investigated.

Precision cut lung slices: a novel versatile tool to examine host-pathogen interaction in the chicken lung.

The avian respiratory tract is a common entry route for many pathogens and an important delivery route for vaccination in the poultry industry. Immune responses in the avian lung have mostly been studied in vivo due to the lack of robust, relevant in vitro and ex vivo models mimicking the microenvironment. Precision-cut lung slices (PCLS) have the major advantages of maintaining the 3-dimensional architecture of the lung and includes heterogeneous cell populations.

Systemic Administration of Avian Defensin 7: Distribution, Cellular Target, and Antibacterial Potential in Mice.

Defensins are natural antimicrobial peptides. The avian beta-defensin AvBD7 isolated from the chicken bone marrow possess broad antibacterial spectrum and strong resistance to proteolysis. However, its ability to fight systemic infections of major concern for public health, such as salmonellosis, is unknown.

Prevalence, risk factors, and characterization of multidrug resistant and extended spectrum β-lactamase/AmpC β-lactamase producing Escherichia coli in healthy horses in France in 2015.

Background: Although antimicrobial resistance is increasingly common in equine medicine, molecular and epidemiological data remains scarce.

Objectives: We estimated the prevalence of, and risk factors for, shedding of multidrug resistant (MDR), extended spectrum β-lactamase (ESBL)-producing, and AmpC β-lactamase-producing, or some combination of these in Escherichia coli in horses in France. We characterized ESBL/AmpC isolates for antimicrobial susceptibility and the presence of virulence and ESBL/AmpC-associated resistance genes.

Use of a Chicken Embryo Lethality Assay to Assess the Efficacy of Phage Therapy.

To combat infectious diseases induced by antibiotic-resistant bacteria in human and animals, phage therapy has regained attention by the scientific community. Before phages can be widely accepted as therapeutics in the same way as antibiotics, convincing detailed applied experimental evidence must be available. The embryonated chicken egg model has been used to study the virulence of many pathogens.