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"Timmerman, J"
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Raw pet food as a risk factor for shedding of extended-spectrum beta-lactamase-producing Enterobacteriaceae in household cats
2017
Close contact between pets and owners provides the opportunity for transmission of antimicrobial resistant organisms like extended-spectrum beta-lactamase (ESBL)/AmpC beta-lactamase (AmpC)-producing Enterobacteriaceae, posing a risk to public health.
To investigate whether raw feed is a risk factor for household cats to shed ESBL-producing Enterobacteriaceae, a cohort study was designed. Additionally, raw and non-raw commercial pet food products were screened for the presence of ESBL-producing Enterobacteriaceae.
Weekly fecal samples of 17 cats in the control group and 19 cats in the exposed group were collected for three weeks and analyzed for the presence of ESBL-producing Enterobacteriaceae. Questionnaires were obtained to determine additional risk factors. Fecal samples were cultured on MacConkey agar supplemented with 1 mg/L cefotaxime. PCR and sequence analysis was used for screening for ESBL genes in suspected isolates. Pet food samples were cultured in LB broth supplemented with 1 mg/L cefotaxime and processed as described above.
In the cohort study, ESBL-producing bacteria were isolated from 3 of 51 (5.9%) samples in the control group compared to 37 of 57 (89.5%) samples in the exposed group. A significant association was found between ESBL shedding and feeding raw pet food products (OR = 31.5). No other risk factors were identified in this study. ESBL-producing Enterobacteriaceae were isolated from 14 of 18 (77.8%) raw pet food products and 0 of 35 non-raw pet food products.
This study shows a strong association between shedding of ESBL-producing bacteria in household cats and feeding raw pet food. Raw pet food was often contaminated with ESBL-producing Enterobacteriaceae.
Journal Article
High Heterogeneity of Escherichia coli Sequence Types Harbouring ESBL/AmpC Genes on IncI1 Plasmids in the Colombian Poultry Chain
by
León, Maribel
,
Wagenaar, Jaap A.
,
Donado-Godoy, Pilar
in
Animal health
,
Animal production
,
Animals
2017
Escherichia coli producing ESBL/AmpC enzymes are unwanted in animal production chains as they may pose a risk to human and animal health. Molecular characterization of plasmids and strains carrying genes that encode these enzymes is essential to understand their local and global spread.
To investigate the diversity of genes, plasmids and strains in ESBL/AmpC-producing E. coli from the Colombian poultry chain isolated within the Colombian Integrated Program for Antimicrobial Resistance Surveillance (Coipars).
A total of 541 non-clinical E. coli strains from epidemiologically independent samples and randomly isolated between 2008 and 2013 within the Coipars program were tested for antimicrobial susceptibility. Poultry isolates resistant to cefotaxime (MIC ≥ 4 mg/L) were screened for ESBL/AmpC genes including blaCTX-M, blaSHV, blaTEM, blaCMY and blaOXA. Plasmid and strain characterization was performed for a selection of the ESBL/AmpC-producing isolates. Plasmids were purified and transformed into E. coli DH10B cells or transferred by conjugation to E. coli W3110. When applicable, PCR Based Replicon Typing (PBRT), plasmid Multi Locus Sequence Typing (pMLST), plasmid Double Locus Sequence Typing (pDLST) and/or plasmid Replicon Sequence Typing (pRST) was performed on resulting transformants and conjugants. Multi Locus Sequence Typing (MLST) was used for strain characterization.
In total, 132 of 541 isolates were resistant to cefotaxime and 122 were found to carry ESBL/AmpC genes. Ninety-two harboured blaCMY-2 (75%), fourteen blaSHV-12 (11%), three blaSHV-5 (2%), five blaCTX-M-2 (4%), one blaCTX-M-15 (1%), one blaCTX-M-8 (1%), four a combination of blaCMY-2 and blaSHV-12 (4%) and two a combination of blaCMY-2 and blaSHV-5 (2%). A selection of 39 ESBL/AmpC-producing isolates was characterized at the plasmid and strain level. ESBL/AmpC genes from 36 isolates were transferable by transformation or conjugation of which 22 were located on IncI1 plasmids. These IncI1 plasmids harboured predominantly blaCMY-2 (16/22), and to a lesser extend blaSHV-12 (5/22) and blaCTX-M-8 (1/22). Other plasmid families associated with ESBL/AmpC-genes were IncK (4/33), IncHI2 (3/33), IncA/C (2/33), IncΒ/O (1/33) and a non-typeable replicon (1/33). Subtyping of IncI1 and IncHI2 demonstrated IncI1/ST12 was predominantly associated with blaCMY-2 (12/16) and IncHI2/ST7 with blaCTX-M-2 (2/3). Finally, 31 different STs were detected among the 39 selected isolates.
Resistance to extended spectrum cephalosporins in E. coli from Colombian poultry is mainly caused by blaCMY-2 and blaSHV-12. The high diversity of strain Sequence Types and the dissemination of homogeneous IncI1/ST12 plasmids suggest that spread of the resistance is mainly mediated by horizontal gene transfer.
Journal Article
Occurrence, Diversity, and Host Association of Intestinal Campylobacter, Arcobacter, and Helicobacter in Reptiles
by
Wagenaar, Jaap A.
,
Gilbert, Maarten J.
,
Duim, Birgitta
in
Amplified fragment length polymorphism
,
Animals
,
Arcobacter - classification
2014
Campylobacter, Arcobacter, and Helicobacter species have been isolated from many vertebrate hosts, including birds, mammals, and reptiles. Multiple studies have focused on the prevalence of these Epsilonproteobacteria genera in avian and mammalian species. However, little focus has been given to the presence within reptiles, and their potential zoonotic and pathogenic roles. In this study, occurrence, diversity, and host association of intestinal Epsilonproteobacteria were determined for a large variety of reptiles. From 2011 to 2013, 444 cloacal swabs and fecal samples originating from 417 predominantly captive-held reptiles were screened for Epsilonproteobacteria. Campylobacter, Arcobacter, and Helicobacter genus specific PCRs were performed directly on all samples. All samples were also cultured on selective media and screened for the presence of Epsilonproteobacteria. Using a tiered approach of AFLP, atpA, and 16S rRNA sequencing, 432 Epsilonproteobacteria isolates were characterized at the species level. Based on PCR, Campylobacter, Arcobacter, and Helicobacter were detected in 69.3% of the reptiles; 82.5% of the chelonians, 63.8% of the lizards, and 58.0% of the snakes were positive for one or more of these genera. Epsilonproteobacteria were isolated from 22.1% of the reptiles and were isolated most frequently from chelonians (37.0%), followed by lizards (19.6%) and snakes (3.0%). The most commonly isolated taxa were Arcobacter butzleri, Arcobacter skirrowii, reptile-associated Campylobacter fetus subsp. testudinum, and a putative novel Campylobacter taxon. Furthermore, a clade of seven related putative novel Helicobacter taxa was isolated from lizards and chelonians. This study shows that reptiles carry various intestinal Epsilonproteobacteria taxa, including several putative novel taxa.
Journal Article
An automated home-cage-based 5-choice serial reaction time task for rapid assessment of attention and impulsivity in rats
2019
RationaleThe 5-choice serial reaction time task (5-CSRTT) is a widely used operant task for measuring attention and motor impulsivity in rodents. Training animals in this task requires an extensive period of daily operant sessions. Recently, a self-paced, automated version of this task has been developed for mice, which substantially reduces training time. Whether a similar approach is effective for rats is currently unknown.ObjectiveHere, we tested whether attention and impulsivity can be assessed in rats with a self-paced version of the 5-CSRTT.MethodsOperant boxes were connected to home-cages with tunnels. Two groups of rats self-paced their training by means of an automated script. The first group of animals was allowed unlimited access (UA) to start trials in the task; for the second group, trial availability was restricted to the first 2.5 h of the dark cycle (TR). Task parameter manipulations, such as variable inter-trial intervals and stimulus durations as well as pharmacological challenges with scopolamine, were tested to validate the task.ResultsSelf-paced training took less than 1 week. Animals in the UA group showed higher levels of omissions compared with the TR group. In both protocols, variable inter-trial intervals increased impulsivity, and variable stimulus durations decreased attentional performance. Scopolamine affected cognitive performance in the TR group only.ConclusionsHome-cage-based training of the 5-CSRTT in rats, especially the TR protocol, presents a valid and fast alternative for measuring attention and impulsivity.
Journal Article
Whole genome-based phylogeny of reptile-associated Helicobacter indicates independent niche adaptation followed by diversification in a poikilothermic host
2017
Reptiles have been shown to host a significant
Helicobacter
diversity. In order to survive, reptile-associated
Helicobacter
lineages need to be adapted to the thermally dynamic environment encountered in a poikilothermic host. The whole genomes of reptile-associated
Helicobacter
lineages can provide insights in
Helicobacter
host adaptation and coevolution. These aspects were explored by comparing the genomes of reptile-, bird-, and mammal-associated
Helicobacter
lineages. Based on average nucleotide identity, all reptile-associated
Helicobacter
lineages in this study could be considered distinct species. A whole genome-based phylogeny showed two distinct clades, one associated with chelonians and one associated with lizards. The phylogeny indicates initial adaptation to an anatomical niche, which is followed by an ancient host jump and subsequent diversification. Furthermore, the ability to grow at low temperatures, which might reflect thermal adaptation to a reptilian host, originated at least twice in
Helicobacter
evolution. A putative tricarballylate catabolism locus was specifically present in
Campylobacter
and
Helicobacter
isolates from reptiles. The phylogeny of reptile-associated
Helicobacter
parallels host association, indicating a high level of host specificity. The high diversity and deep branching within these clades supports long-term coevolution with, and extensive radiation within the respective reptilian host type.
Journal Article
Adenosine A2A Receptors Control Glutamatergic Synaptic Plasticity in Fast Spiking Interneurons of the Prefrontal Cortex
by
Canas, Paula M.
,
Mansvelder, Huibert D.
,
Xavier, Carolina
in
A2A receptor
,
Adenosine
,
Adenosine A2A receptors
2018
Adenosine A2A receptors (A2AR) are activated upon increased synaptic activity to assist in the implementation of long-term plastic changes at synapses. While it is reported that A2AR are involved in the control of prefrontal cortex (PFC)-dependent behavior such as working memory, reversal learning and effort-based decision making, it is not known whether A2AR control glutamatergic synapse plasticity within the medial PFC (mPFC). To elucidate that, we tested whether A2AR blockade affects long-term plasticity (LTP) of excitatory post-synaptic potentials in pyramidal neurons and fast spiking (FS) interneurons in layer 5 of the mPFC and of population spikes. Our results show that A2AR are enriched at mPFC synapses, where their blockade reversed the direction of plasticity at excitatory synapses onto layer 5 FS interneurons from LTP to long-term depression, while their blockade had no effect on the induction of LTP at excitatory synapses onto layer 5 pyramidal neurons. At the network level, extracellularly induced LTP of population spikes was reduced by A2AR blockade. The interneuron-specificity of A2AR in controlling glutamatergic synapse LTP may ensure that during periods of high synaptic activity, a proper excitation/inhibition balance is maintained within the mPFC.
Journal Article
DENDRITIC CELL VACCINES FOR CANCER IMMUNOTHERAPY
by
Levy, MD, Ronald
,
Timmerman, MD, John M.
in
Animals
,
Antigen presentation
,
Antigen Presentation - immunology
1999
Human tumors express a number of protein antigens that can be recognized by
T cells, thus providing potential targets for cancer immunotherapy. Dendritic
cells (DCs) are rare leukocytes that are uniquely potent in their ability to
present antigens to T cells, and this property has prompted their recent
application to therapeutic cancer vaccines. Isolated DCs loaded with tumor
antigen ex vivo and administered as a cellular vaccine have been found to
induce protective and therapeutic anti-tumor immunity in experimental animals.
In pilot clinical trials of DC vaccination for patients with non-Hodgkin's
lymphoma and melanoma, induction of anti-tumor immune responses and tumor
regressions have been observed. Additional trials of DC vaccination for a
variety of human cancers are under way, and methods for targeting tumor
antigens to DCs in vivo are also being explored. Exploitation of the
antigen-presenting properties of DCs thus offers promise for the development of
effective cancer immunotherapies.
Journal Article
Iron deficiency in patients with a Fontan circulation and its impact on exercise capacity
2024
BackgroundIron deficiency (ID) has been reported in patients with congenital heart disease. There is, however, a scarcity of data on its prevalence in patients with a Fontan circulation. The aim of this study is to investigate the prevalence of ID in Fontan patients and to investigate the association between ID and exercise capacity in this population.Methods and resultsBlood count and haematological parameters were determined in plasma of 61 Fontan patients (51% female, mean age 29±9 years). ID was defined as transferrin saturation (TSAT) ≤19.8%. The prevalence of ID was 36% (22/61 patients). Especially among women, the diagnosis of ID was highly prevalent (52%) despite normal haemoglobin levels (153.7±18.4 g/L). Mean ferritin levels were 98±80 µg/L and mean TSAT levels were 22%±12%. Cardiopulmonary exercise testing was performed in 46 patients (75%). Patients with ID had a lower peak oxygen uptake (V̇O2peak) (1397±477 vs 1692±530 mL/min; p=0.039), although this relationship was confounded by sex. The presence of ID increased the likelihood of not achieving a respiratory exchange ratio (RER) ≥1.1 by 5-fold (p=0.035).ConclusionID is highly prevalent among patients with a Fontan circulation. V̇O2peak is lower in patients with ID. Fontan patients with ID are less likely to achieve an RER≥1.1 during cardiopulmonary exercise testing.
Journal Article
Ambulant monitoring and web-accessible home-based exercise program during outpatient follow-up for resected lung cancer survivors: actual use and feasibility in clinical practice
by
Wouters, M.W.J.M.
,
Hermens, H.J.
,
Vollenbroek-Hutten, M.M.R.
in
Anxiety
,
Cancer
,
Cancer Survivors - psychology
2017
Purpose
The aim of this study is to evaluate the feasibility of a telehealthcare application for operable lung cancer (OLC) patients, consisting of ambulant symptom and physical activity monitoring (S&PAM) and a web-accessible home-based exercise program (WEP), and identify possible barriers for successful adoption and implementation.
Methods
A two-stage mixed methods design was used, in which 22 OLC patients and their treating healthcare professionals (HCPs) participated from pre-surgery to three (stage 1;
n
= 10) or six (stage 2;
n
= 12) months post-surgery. Actual use and acceptability (usability, usefulness, and satisfaction) were evaluated.
Results
Seventeen OLC patients (age (SD): 59 (8) years; 8 female) actively used the modules. S&PAM use varied from 1 to 11 monitoring days prior to outpatient consultations. Patients used WEP most frequently during the first 5 weeks, with an average of four logins a week. Fifty-eight percent used WEP beyond 7 weeks. No adverse situations occurred, and patients felt confident using the applications.
Perceived added value included active lifestyle promotion, decreased anxiety, and accessibility to specialized HCPs. Physiotherapists used WEP as intended. Contrarily, physicians scarcely used information from S&PAM. To promote future adoption, strategies should focus on high-level patient tailoring of the technology, and formalization of including the applications in the clinical workflow.
Conclusions
Ambulant monitoring and web-accessible home exercise is clinically feasible for OLC patients. However, low level of adoption by referring physicians may hamper successful implementation.
Implications for cancer survivors
Patients perceived both ambulant monitoring and web-accessible exercise as an added value to regular care and feasible to use in the period before and after lung resection.
Journal Article
Within-Household Transmission and Bacterial Diversity of Staphylococcus pseudintermedius
by
Wegener, Alice
,
Broens, Els M.
,
Wagenaar, Jaap A.
in
antibiotic resistance
,
Antimicrobial resistance
,
bacterial diversity
2022
Staphylococcus pseudintermedius can be transmitted between dogs and their owners and can cause opportunistic infections in humans. Whole genome sequencing was applied to identify the relatedness between isolates from human infections and isolates from dogs in the same households. Genome SNP diversity and distribution of plasmids and antimicrobial resistance genes identified related and unrelated isolates in both households. Our study shows that within-host bacterial diversity is present in S. pseudintermedius, demonstrating that multiple isolates from each host should preferably be sequenced to study transmission dynamics.
Journal Article