Marcus G. Doherr

Prof. Dr. Marcus G. Doherr

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Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2006 in Journal of Clinical Microbiology
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Journal Article
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CSChristina Schnellmann
Christina Schnellmann
VGVinzenz Gerber
Vinzenz Gerber
ARAlexandra Rossano
Alexandra Rossano
VJValentine Jaquier
Valentine Jaquier
YPYann Panchaud
Yann Panchaud
VPVincent Perreten
Vincent Perreten
Because of the frequency of multiple antibiotic resistance,Staphylococcusspecies often represent a challenge in incisional infections of horses undergoing colic surgery. To investigate the evolution of antibiotic resistance patterns before and after preventative peri- and postoperative penicillin treatment, staphylococci were isolated from skin and wound samples at different times during hospitalization. Most staphylococci were normal skin commensals and belonged to the common coagulase-negative group. In some cases they turned out to be opportunistic pathogens present in wound infections. MICs were determined for 12 antibiotics, and antibiotic resistance genes were detected by microarray. At hospital admission, horses harbored staphylococci that were susceptible to antibiotics or resistant to one group of drugs, mainly due to the presence of new variants of the methicillin and macrolide resistance genesmecAandmph(C), respectively. After 3 days, the percentage ofStaphylococcusisolates displaying antibiotic resistance, as well as the number of resistance genes per isolate, increased moderately in hospitalized horses without surgery or penicillin treatment but dramatically in hospitalized horses after colic surgery as well as penicillin treatment.Staphylococcusspecies displaying multiple resistance were found to harbor mainly genes conferring resistance to β-lactams (mecAandblaZ), aminoglycosides [strandaac(6′)-Ie-aph(2′)-Ia], and trimethoprim [dfr(A) anddfr(D)]. Additional genes conferring resistance to macrolides [mph(C),erm(C), anderm(B)], tetracycline [tet(K) andtet(M)], chloramphenicol [cat(pC221) andcat(pC223)], and streptothricin (sat4) appeared in several strains. Hospitalization and preventive penicillin use were shown to act as selection agents for multidrug-resistant commensal staphylococcal flora.

1 May 2009 in Journal of Dairy Science
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Journal Article
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HDH.A. van Dorland
H.A. van Dorland
SRS. Richter
S. Richter
IMI. Morel
I. Morel
Marcus G. DoherrMarcus G. Doherr
Marcus G. Doherr
NCNoemí Castro
Noemí Castro
RBR.M. Bruckmaier
R.M. Bruckmaier
The purpose of this study was to investigate variations in hepatic regulation of metabolism during the dry period, after parturition, and in early lactation in dairy cows. For this evaluation, cows were divided into 2 groups based on the plasma concentration of beta-hydroxybutyric acid (BHBA) in wk 4 postpartum (PP; group HB, BHBA >0.75 mmol/L; group LB, BHBA <0.75 mmol/L, respectively). Liver biopsies were obtained from 28 cows at drying off (mean 59 +/- 8 d antepartum), on d 1, and in wk 4 and 14 PP. Blood samples were collected every 2 wk during this entire period. Liver samples were analyzed for mRNA abundance of genes related to carbohydrate metabolism (pyruvate carboxylase, PC; phosphoenolpyruvate carboxykinase, PEPCK; citrate synthase, CS), fatty acid biosynthesis (ATP citrate lyase, ACLY) and oxidation (acyl-CoA synthetase long-chain, ACSL; carnitine palmitoyltransferase 1A, CPT 1A; carnitine palmitoyltransferase 2, CPT 2; acyl-coenzyme A dehydrogenase very long chain, ACADVL), cholesterol biosynthesis (3-hydroxy-3-methylglutaryl-coenzyme A synthase 1, HMGCS1), ketogenesis (3-hydroxy-3-methylglutaryl-coenzyme A synthase 2, HMGCS2), and of genes encoding the transcription factors peroxisome proliferator-activated receptor alpha (PPARalpha), peroxisome proliferator-activated receptor gamma (PPARgamma), and sterol regulatory element binding factor 1 (SREBF1). Blood plasma was assayed for concentrations of glucose, BHBA, nonesterified fatty acids, cholesterol, triglycerides, insulin, insulin-like growth factor-I, and thyroid hormones. In both groups, plasma parameters followed a pattern usually observed in dairy cows. However, changes were moderate and the energy balance in cows turned positive in wk 7 PP for both groups. Additionally, the energy balance and milk yield were similar for both groups after parturition onwards. Significant group effects were found at drying off, when plasma concentrations of triglycerides were higher in LB than in HB, and in wk 4 PP, when plasma concentrations of glucose and IGF-I were lower in HB than in LB. Similarly, moderate changes in mRNA expression of hepatic genes between the different time points were observed, although HB cows showed more adaptive performance than LB cows based on changes in mRNA expression of PEPCKc, PEPCKm, CS, CPT 1A, CPT 2, and PPARalpha. Part of the variation measured in this study was explained by parity. Significant Spearman rank correlation coefficients between the variables were not similar at each time point and were not similar between the groups at each time point, suggesting that metabolic regulation differs between cows. In conclusion, metabolic regulation in dairy cows is a dynamic system, and differs obviously between cows at different metabolic stages related to parturition.

27 November 1999 in Acta Neuropathologica
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Journal Article
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OSO. Schaller
O. Schaller
RFR. Fatzer
R. Fatzer
MSM. Stack
M. Stack
JCJ. Clark
J. Clark
WCW. Cooley
W. Cooley
MMM. Moser
M. Moser

29 July 2001 in Philosophical Transactions of the Royal Society B: Biological Sciences
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Journal Article
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Marcus G. DoherrMarcus G. Doherr
Marcus G. Doherr
LAL Audigé
L Audigé
Disease monitoring and surveillance systems (MOSSs) have become one of the major components of veterinary activity. Such systems are used to assess the existing levels of prevalence, the effectiveness of control programmes and, after disease eradication, to document the continued absence of disease from a given region or zone. With decreasing disease or infection prevalence, traditional approaches become less reliable and increasingly costly. The objective of this work was to summarize and discuss methodological issues related to veterinary (animal health) MOSSs. There are considerable inconsistencies in the use of the terms ‘monitoring’ and ‘surveillance’. Passive as well as active MOSS have their disadvantages when used for rare health–related events such as emerging and re–emerging diseases. There is a need for evaluation and improvement of these approaches. Integrated systems that call for the use of several parallel surveillance activities seem to be the favoured approach, and analytical methods to combine MOSS data from various sources into a population prevalence, or probability of disease freedom, are under development. The health and safety of the animal and human generations depends on our continuous ability to detect, monitor and control newly emerging or re–emerging livestock diseases and zoonoses rapidly. Uniform surveillance definitions, sound scientifically based approaches that use the resources and data available, and a pool of researchers and veterinary public health officials with sufficient training in epidemiology, are critically important to handle this challenging task.

30 August 2006 in Journal of Small Animal Practice
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Journal Article
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GFG. Fluehmann
G. Fluehmann
Marcus G. DoherrMarcus G. Doherr
Marcus G. Doherr
AJA. Jaggy
A. Jaggy

1 May 2008 in Journal of Veterinary Internal Medicine
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Journal Article
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IBIwan Burgener
Iwan Burgener
AKA. König
A. König
KAK. Allenspach
K. Allenspach
SSS.N. Sauter
S.N. Sauter
JBJ. Boisclair
J. Boisclair
TJT.W. Jungi
T.W. Jungi
Background: Inflammatory bowel disease (IBD) is thought to result from a dysregulated interaction between the host immune system and commensal microflora. Toll-like receptors (TLRs) recognize microbe-associated molecular patterns (MAMPs), but their role in enteropathies in dogs is unknown. Hypothesis: That there is a dysregulation of TLRs recognizing bacterial MAMPs in dogs with IBD. Animals: Sixteen healthy beagles and 12 dogs with steroid-treated (ST) and 23 dogs with food-responsive (FR) diarrhea. Methods: Prospective, observational study. mRNA expression of canine TLR2, 4, and 9 was evaluated by quantitative real-time RT-PCR in duodenal and colonic biopsies obtained before and after standard therapy. Samples from control dogs were taken at necropsy, with additional biopsies of stomach, jejunum, ileum, and mesenteric lymph node in 6 dogs. Results: There were significant differences (P≤ .017) in expression of TLR2, 4, and 9 between the 6 sampled locations in healthy control dogs (lymph node > small intestine ≥ colon). Before therapy, ST expressed more mRNA than control dogs for all 3 receptors (P < .05). There were no significant differences between pretreatment and posttreatment values, even though 32/35 dogs improved clinically. No associations were found when comparing receptor mRNA expression with either histology or clinical activity scores. Conclusions and Clinical Importance: Bacteria-responsive TLR2, 4, and 9 are upregulated in duodenal and colonic mucosa in IBD. This might lead to increased inflammation through interaction with the commensal flora. The absence of significant changes after therapy despite clinical improvement might point toward the existence of a genetic predisposition to IBD as described in human IBD.