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Papers by Geertrui Rasschaert

Antibiotics

The aim of this study was metagenomics analyses of acquired antibiotic-resistance genes (ARGs) in... more The aim of this study was metagenomics analyses of acquired antibiotic-resistance genes (ARGs) in the intestinal microbiome of two important food-animal species in Hungary from a One Health perspective. Intestinal content samples were collected from 12 domestic pigs (Sus scrofa) and from a common carp (Cyprinus carpio). Shotgun metagenomic sequencing of DNA purified from the intestinal samples was performed on the Illumina platform. The ResFinder database was applied for detecting acquired ARGs in the assembled metagenomic contigs. Altogether, 59 acquired ARG types were identified, 51 genes from domestic pig and 12 genes from the carp intestinal microbiome. ARG types belonged to the antibiotic classes aminoglycosides (27.1%), tetracyclines (25.4%), β-lactams (16.9%), and others. Of the identified ARGs, tet(E), a blaOXA-48-like β-lactamase gene, as well as cphA4, ampS, aadA2, qnrS2, and sul1, were identified only in carp but not in swine samples. Several of the detected acquired ARGs...

International Journal of Food Contamination, Jul 23, 2015

Zoonoses and Public Health, Aug 28, 2012

SummaryDuring the last few years, methicillin‐resistant Staphylococcus aureus (MRSA) ST398 has be... more SummaryDuring the last few years, methicillin‐resistant Staphylococcus aureus (MRSA) ST398 has been isolated frequently from livestock, especially from pigs and to a lesser extent from cattle and poultry. To gain insight into the distribution of this bacterium in pig farms versus multispecies farms, 30 Belgian farms (10 pig, 10 pig/poultry and 10 pig/cattle farms) were screened for the presence of MRSA. On each farm, 10 nasal swabs were taken from pigs. When present, cattle (n = 10) were sampled in the nares and poultry (n = 10) in the nares, earlobes and cloaca. A selection of the obtained isolates were further characterized using multilocus sequence typing (MLST), spa typing, SCCmec typing, pulsed field gel electrophoresis (PFGE), multiple‐locus variable‐number tandem repeat analysis (MLVA) and antimicrobial susceptibility testing. On 26 of 30 farms, MRSA was isolated from pigs. Furthermore, MRSA was also isolated from poultry and cattle on one pig/poultry and five pig/cattle farms, respectively. All tested MRSA isolates belonged to ST398. Eight spa types (t011, t034, t567, t571, t1451, t2974, t3423 and t5943) were detected, among which t011 predominated. SCCmec cassettes type IVa and V were present in 20% and 72% of the isolates, respectively. When combining the results of the two remaining typing methods, PFGE and MLVA, eighteen genotypes were obtained of which one genotype predominated (56% of the positive farms). All MRSA isolates were resistant to tetracycline. Resistance to trimethoprim, aminoglycosides, macrolides, lincosamides, fluoroquinolones and chloramphenicol was also observed. In conclusion, there was no effect of the farm type on the MRSA status of the pigs. A statistically significant difference was observed when comparing the pig/poultry or the pig/cattle MRSA status on the multispecies farms. Additionally, a wide variety of MRSA ST398 strains was found within certain farms when combining different typing methods.

International Conference on the Epidemiology and Control of Biological, Chemical and Physical Hazards in Pigs and Pork, 2015

After the recognition of hospital-associated MRSA and community-associated MRSA, recently a new l... more After the recognition of hospital-associated MRSA and community-associated MRSA, recently a new lineage of MRSA was found in livestock, mainly in pigs (LA-MRSA). It was hypothesized that the presence of different livestock species could contribute to a higher prevalence of LA-MRSA on a farm.The aim of the study was to gain insights into the prevalence on Belgian mixed farms and to compare the antibacterial resistance pattern of MRSA. Between January 2009 and January 2013, 2 mixed poultry-pig farms and 3 mixed cattle-pig farms were sampled 3 times for pigs and cattle and 6 times for poultry. On each sampling round, nose swabs of pigs (n=10) and cattle (n=10) were taken, whereas swabs of nose shells and cloaca from poultry (n=10). Swabs were pooled per two for examination. In pigs, 64% of the pooled samples were found MRSA positive, whereas for cattle and poultry this was 12% and 10%, respectively. On the mixed poultry-pig farms, 83% of the samples of pigs were positive compared to 51% on mixed cattle-pig farms. MRSA was found in pigs during each sampling round. On all farms MRSA was isolated from broilers or cattle, however, MRSA was only found in poultry during sampling round 1 and 2 and in cattle during sampling round 1 and 3. Overall, resistance was found against 10of the 16 tested antibiotics. In only one sample resistance was reported against an antibiotic used on the farm (trimethoprim in pigs).These results indicate that LA-MRSA was present on each farm and in each animal species. The prevalence seems higher in pigs compared to poultry and cattle. The prevalence seems also higher in pigs housed in pig-poultry farms comparing to the prevalence in pigs in pig-cattle farms. There was no link between the resistance pattern and the use of antibiotics on the farms.

Genome Announcements, Jun 26, 2014

In this study, we present a draft genome sequence of Enterococcus faecalis MB5259, a promising pr... more In this study, we present a draft genome sequence of Enterococcus faecalis MB5259, a promising probiotic strain. The identified differences and common features between this strain and reference strains will assist in better understanding the mechanism of antibacterial action and in developing novel probiotics.

Journal of Dairy Science, May 1, 2017

The aim of this study was to develop and validate 2 protocols (for use on-farm and at a central l... more The aim of this study was to develop and validate 2 protocols (for use on-farm and at a central location) for the reduction of Mycobacterium avium ssp. paratuberculosis (MAP) in colostrum while preserving beneficial immunoglobulins (IgG). The on-farm protocol was based on curdling of the colostrum, where the IgG remain in the whey and the MAP bacteria are trapped in the curd. First, the colostrum was diluted with water (2 volumes colostrum to 1 volume water) and 2% rennet was added. After incubation (1 h at 32°C), the curd was cut and incubated again, after which whey and curd were separated using a cheesecloth. The curd was removed and milk powder was added to the whey. Approximately 1 log reduction in MAP counts was achieved. A reduction in total proteins and IgG was observed due to initial dilution of the colostrum. After curd formation, more than 95% of the immunoglobulins remained in the whey fraction. The semi-industrial protocol was based on centrifugation, which causes MAP to precipitate, while the IgG remain in the supernatant. This protocol was first developed in the laboratory. The colostrum was diluted with skimmed colostrum (2 volumes colostrum to 1 volume skimmed colostrum), then skimmed and centrifuged (at 15,600 × g for 30 min at room temperature). We observed on average 1.5 log reduction in the MAP counts and a limited reduction in proteins and IgG in the supernatant. To obtain a semi-industrial protocol, dairy pilot appliances were evaluated and the following changes were applied to the protocol: after 2:1 dilution as above, the colostrum was skimmed and subsequently clarified, after which the cream was heat treated and added to the supernatant. To investigate the effect of the colostrum treatment on the nutritional value and palatability of the colostrum and the IgG transfer, an animal experiment was conducted with 24 calves. Six received the dam's colostrum, 6 were given untreated purchased colostrum (control), and 2 groups of 6 calves received colostrum treated according to both of the above-mentioned methods. No significant differences were found between the test groups and the dam's colostrum group in terms of animal health, IgG uptake in the blood serum, milk, or forage uptake. Two protocols to reduce MAP in colostrum (for use on-farm or at a central location) were developed. Both methods preserve the vital IgG.

International Symposium: Alternatives to Antibiotics (ATA), 2012

Twenty-first Conference on Food Microbiology, 2016