224 research outputs found
Prevalence of Rabbit Hemorrhagic Disease (RHD) in wild rabbits (Oryctolagus cuniculus) in Flanders, Belgium, 1999-2002
During the period of July 1999 through June 2002, carcasses of wild rabbits that had been shot or found dead and livers originating from wild rabbits that had been shot for consumption were collected in Flanders. One hundred and twelve carcasses were suitable for necropsy and histological and bacteriological analysis; histological analysis was possible in 41 livers. Considering the 112 rabbit carcasses only, Rabbit Hemorrhagic Disease (RHD) was found to be present in 33.9% of the cases. RHD was the most prevalent wild rabbit pathology detected in this study, before staphylococcosis (12.5%), and myxomatosis (10.7%). None of the liver samples from rabbits shot for consumption were positive for RHD. Of the 38 histologically RHD positive samples, 24 were analyzed with the hemagglutination (HA) technique, yielding 58.3% positive results. Seven samples that were histologically positive for RHD but HA negative were examined by transmission electron microscopy and were found positive for calicivirus. This proves that HA-negative RHD strains are circulating in the Flemish wild rabbit population
Serological profiles in nursery piglets colonized with Staphylococcus aureus
At present, the immune response of pigs in relation to Staphylococcus aureus carriage is poorly understood. This study aimed at investigating the dynamics of the anti-staphylococcal humoral immune response in methicillin-susceptible S. aureus (MSSA)-positive piglets and at assessing the effect of the experimental introduction of a methicillin-resistant S. aureus (MRSA) Sequence Type (ST) 398 strain. Therefore, serum samples were collected at different times from 31 weaned piglets originating from four different sows. Twenty-four out of the 31 piglets were challenged with MRSA ST398. The serum samples were analysed for IgG antibodies to 39 S. aureus antigens, using a multiplex bead-based assay (xMAP technology, Luminex Corporation). Though antibody responses showed broad inter-individual variability, serological results appeared to be clustered by litter of origin. For most antigens, an age-related response was observed with an apparent increase in antibody titres directed against staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), which have been shown to play a role in S. aureus colonization. In most animals, antibody titres directed against staphylococcal toxins or immune-modulating proteins decreased with age, possibly reflecting absence of bacterial invasion. The introduction of MRSA ST398 did not elicit a significant humoral immune reaction.
This study describes, for the first time, the humoral immune response in weaned pigs colonized with S. aureus
Gevoeligheid van belgische Mycoplasma Hyopneumoniae isolaten voor antimicrobiële middelen
To control Mycoplasma hyopneumoniae infections, the use of antibiotics in feed or water is a common practice. Unfortunately, information concerning the susceptibility of M. hyopneumoniae to different antimicrobials is very scarce. The in vitro susceptibility of 21 M hyopneumoniae field isolates was determined in this study using a broth microdilution technique. Acquired resistance to spectinomycin, oxytetracycline, doxycycline, gentamicin, florfenicol and tiamulin was not observed. One isolate showed acquired resistance to lincomycin, tilmicosin and tylosin, but was susceptible to all other antibiotics tested. For 5 isolates, the MIC-values of flumequine were > 16 mu g/ml, while the MIC50-value was 2 mu g/ml. The MIC-values of enrofloxacin for these 5 isolates were >= 0.5 mu g/ml, the MIC50 being 0.06 mu g/ml. This is the first report showing acquired resistance against macrolides, lincosamides and fluoroquinolones in M hyopneumoniae field isolates
Relation between antimicrobial use and resistance in Belgian pig herds
The aim of this study was to determine the link between the characteristics of antimicrobial therapy and occurrence of antimicrobial resistance in Escherichia coli of clinically healthy pigs exposed to antimicrobial treatments. A total of 918 Escherichia coli isolates were obtained from faecal samples, collected from 50 pig herds at the end of the fattening period and susceptibility was tested towards 15 different antimicrobial agents, using the disk diffusion method
Transmission study of Salmonella in pigs with 3 intervention strategies
In this study, the effect of 3 different intervention strategies on the transmission of Salmonella in pigs was evaluated: feed supplementation with coated calcium-butyrate salt, vaccination and acidified drinking water. Strategies were evaluated serologically and bacteriologically using an experimental in vivo seeder setup. Significantly higher antibody titers were detected in the groups with acidified drinking water and vaccination
Methicillin-Resistant Staphylococcus aureus ST398 in Swine Farm Personnel, Belgium
We assessed methicillin-resistant Staphylococcus aureus (MRSA) in persons on 49 swine farms in Belgium. Surveys showed that 48 (37.8%) persons carried MRSA ST398 and 1 (0.8%) had concurrent skin infection. Risk factors for carriage were MRSA carriage by pigs, regular contact with pigs and companion animals, and use of protective clothing
Selection and transfer of an IncI1-tet(A) plasmid of Escherichia coli in an ex vivo model of the porcine caecum at doxycycline concentrations caused by cross-contaminated feed
Aims: The aim of this study was to investigate the effect of subtherapeutic intestinal doxycycline (DOX) concentrations (4 and 1mgl(-1)), caused by cross-contamination of feed, on the enrichment of a DOX-resistant commensal Escherichia coli and its resistance plasmid in an exvivo model of the porcine caecum.
Methods and Results: A DOX-resistant, tet(A)-carrying, porcine commensal E.coli strain (EC 682) was cultivated for 6days in the porcine caecum model under different conditions (0, 1 and 4mgl(-1) DOX). EC 682, other coliforms and anaerobic bacteria were enumerated daily. A selection of isolated DOX-resistant coliforms (n=454) was characterized by rep-PCR clustering, PCR assays (Inc1 and tet(A)) and micro broth dilution susceptibility tests (Sensititre). Both 1 and 4mgl(-1) DOX-enriched medium had a significantly higher selective effect on EC 682 and other resistant coliforms than medium without DOX. Transconjugants of EC 682 were isolated more frequently in the presence of 1 and 4mgl(-1) DOX compared to medium without DOX.
Conclusions: Subtherapeutic intestinal DOX concentrations have the potential to select for DOX-resistant E.coli, and promote the selection of transconjugants in a porcine caecum model.
Significance and Impact of the Study: Cross-contamination of feed with antimicrobials such as DOX likely promotes the spread of antimicrobial resistance. Therefore, it is important to develop or fine-tune guidelines for the safe use of antimicrobials in animal feed and its storage
Comparative analysis of extended-spectrum-β-lactamase-carrying plasmids from different members of Enterobacteriaceae isolated from poultry, pigs and humans: evidence for a shared β-lactam resistance gene pool?
Occurrence of antimicrobial resistance among bacterial pathogens and indicator bacteria in pigs in different European countries from year 2002 – 2004 : the ARBAO-II study
Background: The project "Antibiotic resistance in bacteria of animal origin – II" (ARBAO-II) was
funded by the European Union (FAIR5-QLK2-2002-01146) for the period 2003–05. The aim of this
project was to establish a program for the continuous monitoring of antimicrobial susceptibility of
pathogenic and indicator bacteria from food animals using validated and harmonised
methodologies. In this report the first data on the occurrence of antimicrobial resistance among
bacteria causing infections in pigs are reported.
Methods: Susceptibility data from 17,642 isolates of pathogens and indicator bacteria including
Actinobacillus pleuropneumoniae, Streptococcus suis and Escherichia coli isolated from pigs were
collected from fifteen European countries in 2002–2004.Results: Data for A. pleuropneumoniae from infected pigs were submitted from five countries. Most
of the isolates from Denmark were susceptible to all drugs tested with the exceptions of a low
frequency of resistance to tetracycline and trimethoprim – sulphonamide.
Data for S. suis were obtained from six countries. In general, a high level of resistance to
tetracycline (48.0 – 92.0%) and erythromycin (29.1 – 75.0%) was observed in all countries whereas
the level of resistance to ciprofloxacin and penicillin differed between the reporting countries.
Isolates from England (and Wales), France and The Netherlands were all susceptible to penicillin.
In contrast the proportion of strains resistant to ciprofloxacin ranged from 12.6 to 79.0% (2004)
and to penicillin from 8.1 – 13.0% (2004) in Poland and Portugal.
Data for E. coli from infected and healthy pigs were obtained from eleven countries. The data reveal
a high level of resistance to tetracyclines, streptomycin and ampicillin among infected pigs whereas
in healthy pigs the frequency of resistance was lower.
Conclusion: Bacterial resistance to some antimicrobials was frequent with different levels of
resistance being observed to several antimicrobial agents in different countries. The occurrence of
resistance varied distinctly between isolates from healthy and diseased pigs, with the isolates from
healthy pigs generally showing a lower level of resistance than those from diseased pigs.
The study suggests that the choice of antimicrobials used for the treatment of diseased animals
should preferably be based on knowledge of the local pattern of resistance
Occurrence of antimicrobial resistance among bacterial pathogens
Background: The project "Antibiotic resistance in bacteria of animal origin – II" (ARBAO-II) was
funded by the European Union (FAIR5-QLK2-2002-01146) for the period 2003–05. The aim of this
project was to establish a program for the continuous monitoring of antimicrobial susceptibility of
pathogenic and indicator bacteria from food animals using validated and harmonised
methodologies. In this report the first data on the occurrence of antimicrobial resistance among
bacteria causing infections in pigs are reported.
Methods: Susceptibility data from 17,642 isolates of pathogens and indicator bacteria including
Actinobacillus pleuropneumoniae, Streptococcus suis and Escherichia coli isolated from pigs were
collected from fifteen European countries in 2002–2004.Results: Data for A. pleuropneumoniae from infected pigs were submitted from five countries. Most
of the isolates from Denmark were susceptible to all drugs tested with the exceptions of a low
frequency of resistance to tetracycline and trimethoprim – sulphonamide.
Data for S. suis were obtained from six countries. In general, a high level of resistance to
tetracycline (48.0 – 92.0%) and erythromycin (29.1 – 75.0%) was observed in all countries whereas
the level of resistance to ciprofloxacin and penicillin differed between the reporting countries.
Isolates from England (and Wales), France and The Netherlands were all susceptible to penicillin.
In contrast the proportion of strains resistant to ciprofloxacin ranged from 12.6 to 79.0% (2004)
and to penicillin from 8.1 – 13.0% (2004) in Poland and Portugal.
Data for E. coli from infected and healthy pigs were obtained from eleven countries. The data reveal
a high level of resistance to tetracyclines, streptomycin and ampicillin among infected pigs whereas
in healthy pigs the frequency of resistance was lower.
Conclusion: Bacterial resistance to some antimicrobials was frequent with different levels of
resistance being observed to several antimicrobial agents in different countries. The occurrence of
resistance varied distinctly between isolates from healthy and diseased pigs, with the isolates from
healthy pigs generally showing a lower level of resistance than those from diseased pigs.
The study suggests that the choice of antimicrobials used for the treatment of diseased animals
should preferably be based on knowledge of the local pattern of resistance
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