and
are commonly co-isolated with
(primary agent of swine enzootic pneumonia) in gross pneumonia-like lesions, but their involvement in the disease process remains unknown. T cells play an ...immuno-pathological role during mycoplasmal infections. Dendritic cells (DCs) are major antigen-presenting cells involved in T cell activation and differentiation. In this study, we investigated cytokine (IL-6, IL-8, IL-10, IL-12, and TNF-α) production by porcine bone-marrow-derived DCs (BM-DCs) stimulated by
,
, and/or
. Results showed that cytokine production levels were relatively homogenous for all evaluated
strains in contrast to
and
strains. The most noteworthy inter-species differences were the overall (i) lower IL-12 production capacity of
, and (ii) higher TNF-α production capacity of
. Co-stimulation of BM-DCs showed that
dominated the IL-12 production independently of its association with
or
. In addition, a decreased BM-DC production of TNF-α was generally observed in the presence of mycoplasma associations. Lastly,
association with
increased BM-DC ability to secrete IL-10. A higher cytotoxicity level in BM-DCs stimulated by
was also observed. Overall, this study demonstrated that the combination of
or
with
may participate to the modulation of the immune response that might affect the final disease outcome.
•The inoculated cefotaxime-resistant E. coli was a good pig gut colonizer.•Probiotics could not reduce faecal excretion of resistant E. coli in inoculated pigs.•Resistant E. coli titers were lower in ...digestive tracts of the probiotic-treated pigs.•No transfer of the blaCTX−M-1 gene was detected.
We evaluated the impact of the administration of two Escherichia coli probiotic strains (ED1a and Nissle 1917) to pigs on the gut carriage or shedding of extended-spectrum beta-lactamase-producing E. coli. The probiotics were given to four sows from 12 days before farrowing to the weaning day, and to the 23 piglets (infected treated group (IPro)) from birth to the age of 49 days. Four other sows and their 24 piglets (infected non-treated group (INT)) did not receive the probiotics. IPro and INT piglets (n = 47) were orally inoculated with the strain E. coli 17–348F-RifR carrying the blaCTX−M-1 gene and resistant to rifampicin. Cefotaxime-resistant (CTXR) E. coli and rifampicin-resistant (RifR) E. coli were cultured and excretion of probiotics was studied using PCR on individual faecal and post-mortem samples, and from manure collected after the challenge with resistant E. coli. CTXR and RifRE.coli isolates were characterized to detect transfer of the blaCTX−M-1 to other strains.. Overall, there was no significant reduction in faecal excretion of CTXR and RifRE. coli in IPro pigs compared with INT pigs, although the CTXR and RifRE. coli titres were slightly, but significantly lower in the colon, caecum and rectum at post mortem. Excretion of the probiotics decreased with age, but Nissle 1917 was detected in most pigs at post-mortem. No transfer of the blaCTX−M-1 gene to probiotic and other E. coli strains was detected. In conclusion, in our experimental conditions, the used probiotics did not reduce shedding of the challenge strain.
Antibiotic resistance, particularly with the fluoroquinolones and macrolide antibiotics, has now emerged globally with thermophilic campylobacters, including
Campylobacter jejuni and
C. coli, giving ...rise to concerns about how these organisms have acquired such resistance characteristics, as well as consequences for human and animal treatment. This review examines (i) the clinical epidemiology of antibiotic resistance in human and animal thermophilic campylobacters, (ii) an update on resistance rates globally, (iii) surveillance of antimicrobial resistance in campylobacters originating from animals, particularly poultry, (iv) the role of the environment in the acquisition and transmission of antibiotic-resistant campylobacters, as well as (v) issues of biocide resistance in campylobacters.
The tcr gene cluster mediates in vitro copper resistance in Enterococcus faecium. Here we describe the selection of tcr-mediated copper resistance in E. faecium in an animal feeding experiment with ...young pigs fed 175 mg copper/kg feed (ppm), which is the concentration commonly used for piglets in European pig production. tcr-mediated copper resistance was not selected for in a control group fed low levels of copper (6 ppm). We also show coselection of macrolide- and glycopeptide-resistant E. faecium in the animal group fed the high level of copper. Finally, we identify the tcr genes in the enterococcal species E. mundtii, E. casseliflavus, and E. gallinarum for the first time.
We describe isolates from human Campylobacter infection in the French population and the isolates' antimicrobial drug resistance patterns since 1986 and compare the trends with those of isolates from ...broiler chickens and pigs from 1999 through 2004. Among 5,685 human Campylobacter isolates, 76.2% were C. jejuni, 17.2% C. coli, and 5.0% C. fetus. Resistance to nalidixic acid increased from 8.2% in 1990 to 26.3% in 2004 (p < 10(-3)), and resistance to ampicillin was high over time. Nalidixic acid resistance was greater for C. coli (21.3%) than for C. jejuni (14.9%, p < 10(-3)). C. jejuni resistance to ciprofloxacin in broilers decreased from 31.7% in 2002 to 9.0% in 2004 (p = 0.02). The patterns of resistance to quinolones and fluoroquinolones were similar between 1999 and 2004 in human and broiler isolates for C. jejuni. These results suggest a potential benefit of a regulation policy limiting use of antimicrobial drugs in food animals.
Enterococcus cecorum, a commensal Gram-positive bacterium of the chicken gut, has emerged as a worldwide cause of lameness in poultry, particularly in fast-growing broilers. It is responsible for ...osteomyelitis, spondylitis, and femoral head necrosis, causing animal suffering, mortality, and antimicrobial use. Research on the antimicrobial resistance of E. cecorum clinical isolates in France is scarce, and epidemiological cutoff (ECOFF) values are unknown. To determine tentative ECOFF (CO
) values for
and to investigate the antimicrobial resistance patterns of isolates from mainly French broilers, we tested the susceptibility of a collection of commensal and clinical isolates (
= 208) to 29 antimicrobials by the disc diffusion (DD) method. We also determined the MICs of 23 antimicrobials by the broth microdilution method. To detect chromosomal mutations conferring antimicrobial resistance, we investigated the genomes of 118
isolates obtained mainly from infectious sites and described previously in the literature. We determined the CO
values for more than 20 antimicrobials and identified two chromosomal mutations explaining fluoroquinolone resistance. The DD method appears better suited for detecting
antimicrobial resistance. Although tetracycline and erythromycin resistances were persistent in clinical and nonclinical isolates, we found little or no resistance to medically important antimicrobials.
Enterococci are commensal intestinal bacteria and opportunistic pathogens in humans and animals. Enterococcus-associated diseases are an emerging health issue in poultry. The aim of this ...retrospective study was to assess the occurrence of enterococci in poultry in France with regard to the manifested diseases and the affected avian species. Our analysis is based on veterinary laboratory data collected by the French poultry epidemiological surveillance network (RNOEA) that monitors avian diseases in France based on the voluntary participation of its veterinarian members. Since the creation of the network in 1989, 12, 177 Enterococcus cases have been reported by veterinary laboratories (Enterococcus cecorum 53.1% and Enterococcus faecalis 24.3%), with emergence starting in 2006, year in which Enterococcus represented 0.4% of all reported pathogens, and incidence growing to 12.9% in 2020. The main diseases associated with these reports were locomotor disorders 35.2% (mainly involving E. cecorum 77.9%), septicaemia 34.9% (involving E. cecorum 53.4% and E. faecalis 23.8%), and omphalitis 14.4% (mainly involving E. faecalis 59.5%). Most of these Enterococcus-associated diseases (71.5%) were reported in broilers (particularly affected by the locomotor disorders and septicaemia involving E. cecorum), accounting for 9.1% of all the diseases reported in this production sector, with an increase from 1.4% in 2006 to 17.2% in 2020. This study highlights the emergence of enterococcal diseases in poultry in France over the past 15 years and the need to maintain a surveillance system.
•French surveillance revealed a high incidence of enterococcal infections in poultry.•Enterococcus increased from 0.4% of all reported poultry pathogens in 2006–12.9% in 2020.•Emergence of Enterococcus spp in poultry is mainly caused by E. cecorum and E. faecalis.•Broilers are the main production sector affected by enterococcal diseases.•Locomotor disorders and septicaemia in broilers are mainly attributed to E. cecorum.
Enterococcus cecorum is a member of the normal poultry gut microbiota and an emerging poultry pathogen. Some strains are resistant to key antibiotics and coccidiostats. We evaluated the impact on ...chicken excretion and persistence of a multidrug-resistant E. cecorum of administering narasin or antibiotics. E. cecorum CIRMBP-1294 (Ec1294) is non-wild-type to many antimicrobials, including narasin, levofloxacin, oxytetracycline and glycopeptides, it has a low susceptibility to amoxicillin, and carries a chromosomal vanA operon. Six groups of 15 chicks each were orally inoculated with Ec1294 and two groups were left untreated. Amoxicillin, oxytetracycline or narasin were administered orally to one group each, either at the recommended dose for five days (amoxicillin, oxytetracycline) or continuously (narasin). Faecal samples were collected weekly and caecal samples were obtained from sacrificed birds on day 28. Ec1294 titres were evaluated by culture on vancomycin- and levofloxacin-supplemented media in 5 % CO2. For inoculated birds given narasin, oxytetracycline or no antimicrobials, vancomycin-resistant enterococci were searched by culture on vancomycin-supplemented media incubated in air, and a PCR was used to detect the vanA gene. Ec1294 persisted in inoculated chicks up to day 28. Compared to the control group, the Ec1294 titre was significantly lower in the amoxicillin- and narasin-receiving groups on days 21 and 28, but was unexpectedly higher in the oxytetracycline-receiving group before and after oxytetracycline administration, preventing a conclusion for this group. No transfer of the vanA gene to other enterococci was detected. Other trials in various experimental conditions should now be conducted to confirm this apparent absence of co-selection of the multi-drug-resistant E. cecorum by narasin or amoxicillin administration.
●An experimental model of Enterococcus cecorum gut carriage in chickens was developed.●Inoculation of day-old chicks with E. cecorum led to intestinal carriage up to day 28.●Narasin administration did not select the narasin- and antibiotic-resistant E. cecorum.●Transfer of the E. cecorum chromosomal vanA gene to other enterococci was not detected.
ABSTRACT
Multiresistance plasmids belonging to the IncI incompatibility group have become one of the most pervasive plasmid types in extended-spectrum beta-lactamase-producing
Escherichia coli
of ...animal origin. The extent of the burden imposed on the bacterial cell by these plasmids seems to modulate the emergence of “epidemic” plasmids. However,
in vivo
data in the natural environment of the strains are scarce. Here, we investigated the cost of a
bla
CTX-M-1
-IncI1 epidemic plasmid in a commensal
E. coli
animal strain, UB12-RC, before and after oral inoculation of 15 6- to 8-week- old specific-pathogen-free pigs. Growth rate in rich medium was determined on (i) UB12-RC and derivatives, with or without plasmid,
in vivo
and/or
in vitro
evolved, and (ii) strains that acquired the plasmid in the gut during the experiment. Although
bla
CTX-M-1
-IncI1 plasmid imposed no measurable burden on the recipient strain after conjugation and during the longitudinal carriage in the pig’s gut, we observed a significant difference in the bacterial growth rate between IncI1 plasmid-carrying and plasmid-free isolates collected during
in vivo
carriage. Only a few mutations on the chromosome of the UB12-RC derivatives were detected by whole-genome sequencing. RNA-Seq analysis of a selected set of these strains showed that transcriptional responses to the
bla
CTX-M-1
-IncI1 acquisition were limited, affecting metabolism, stress response, and motility functions. Our data suggest that the effect of IncI plasmid on host cells is limited, fitness cost being insufficient to act as a barrier to IncI plasmid spread among natural population of
E. coli
in the gut niche.
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