Peter Kuhnert

Peter Kuhnert
Universität Bern | UniBe · Institute of Veterinary Bacteriology

PhD

About

430
Publications
30,267
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
7,711
Citations
Introduction
My research as microbiologist focuses on bacterial virulence, molecular epidemiology, phylogeny and taxonomy. Thereby a broad variety of animal as well as zoonotic human pathogens are covered. It includes e.g. virulence mechanisms of Pasteurellaceae or genotyping of Mycoplasma hyopneumoniae, as well as source attribution and pathogenesis of Campylobacter, or pathotyping of E. coli. More recently, molecular diagnosis and pathogenesis of infectious hoof diseases like ovine foot-rot caused by Dichelobacter nododus and bovine digital dermatitis triggered by Treponema species are a focus of my research.
Additional affiliations
November 2012 - April 2013
University of Technology Sydney
Position
  • Professor
Description
  • Proteomics on Campylobacter and Mycoplasma hyopneumoniae
April 1993 - March 1994
Weizmann Institute of Science
Position
  • Postoctoral fellow
Description
  • Regulation of the human TNF-receptor genes and its role in the immune response
June 1989 - February 1993
Universität Bern
Position
  • PhD Student
Description
  • Gene regulation of the porcine TNF-locus

Publications

Publications (430)
Article
Full-text available
Ovine footrot is a highly contagious foot disease caused by the gram-negative bacterium Dichelobacter nodosus (D. nodosus). In a recent report, we showed a prevalence of 42.9% D. nodosus positive swabs across Germany. In this follow-up study, we used real-time PCR results for D. nodosus and footrot scores of 9297 sheep from 208 flocks and collated...
Article
Seven bacterial strains isolated from bovine endocarditis in six animals from different geographic regions were investigated in a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences placed all seven isolates on a distinct, monophyletic cluster in the family Neisseriaceae with closest similarity to type strains of A...
Article
Full-text available
Mycoplasma hyopneumoniae is the etiological agent of enzootic pneumonia (EP), an economically important chronic respiratory disease in pigs. M. hyopneumoniae impacts the mucociliary clearance system by disrupting the cilia and modulates the immune response, resulting in intermittent dry non-productive cough. For progressive control of EP in Switzer...
Article
Full-text available
Footrot is one of the major causes of lameness in sheep and leads to decreased animal welfare and high economic losses. The causative agent is the Gram-negative anaerobic bacterium Dichelobacter nodosus. The prevalence of D. nodosus in 207 sheep flocks across Germany was 42.9%. Based on the sequence variation in the type IV fimbrial gene fimA, D. n...
Article
Full-text available
Mycoplasma hyopneumoniae ( M. hyopneumoniae ) is one of the primary agents involved in the porcine respiratory disease complex, economically one of the most important diseases in pigs worldwide. The pathogen adheres to the ciliated epithelium of the trachea, bronchi, and bronchioles, causes damage to the mucosal clearance system, modulates the immu...
Article
We report here the complete genome sequence of the widely studied Actinobacillus pleuropneumoniae serovar 8 reference strain 405, generated using the Pacific Biosciences (PacBio) RS II platform. Furthermore, we compared draft sequences generated by Illumina sequencing of six stocks of this strain, including the same original stock used to generate...
Article
Full-text available
Mycoplasmas are minute bacteria controlled by very small genomes ranging from 0.6 to 1.4 Mbp. They encompass several important medical and veterinary pathogens that are often associated with a wide range of chronic diseases. The long persistence of mycoplasma cells in their hosts can exacerbate the spread of antimicrobial resistance observed for ma...
Article
Full-text available
A newly-discovered foot disease of unknown origin in captive European Bison ( Bison bonasus ) was recently detected at Berne Animal Park. Dermatitis of the interdigital cleft of varying degrees of severity was diagnosed in all animals ( n = 10). The aim of this study was to describe the gross and histological lesions of the interdigital cleft found...
Article
[ Haemophilus ] haemoglobinophilus and the unpublished Bisgaard taxon 35 are associated with respiratory and urogenital tract infections in dogs. A total of 21 strains including the type strain of [ Haemophilus ] haemoglobinophilus were included in the investigation. Strains of [ Haemophilus ] haemoglobinophilus and taxon 35 formed a monophyletic g...
Article
Full-text available
We report the complete 2,783,931-bp circular genome sequence of the human methicillin-resistant strain Staphylococcus aureus 17Gst354, isolated from a nasal swab. The strain possessed an additional 4,397-bp plasmid. Moreover, we induced and sequenced its temperate phage Staphylococcus phage vB_StaphS-IVBph354, which has a circular genome of 41,970...
Article
Full-text available
The bacterium Dichelobacter nodosus (D. nodosus) is the causative agent of ovine footrot. The aim of this field study was to determine the prevalence of D. nodosus in German sheep flocks. The sheep owners participated voluntarily in the study. More than 9000 sheep from 207 flocks were screened for footrot scores using a Footrot Scoring System from...
Article
Digital dermatitis (DD) is a major infectious foot disease of cattle worldwide. Some DD stages are associated with lameness, and the disease has significant economic and animal welfare consequences. The pathogenesis of the disease is not yet fully understood, but Treponema spp. have been associated consistently with clinical cases. Isolation of the...
Chapter
This book contains 14 chapters that discuss the genetics, epidemiology, prevalence, pathogenesis, clinical signs, diagnosis, treatment, prevention and control of Mycoplasma infections in pigs. Chapter 1 discusses the phylogenetics and classification of Mycoplasma species in pigs; Chapter 2 describes the genomic diversity and antigenic variation of...
Article
Full-text available
Footrot is a contagious foot disease mainly affecting sheep. It is caused by the Gram-negative anaerobic bacterium Dichelobacter nodosus. Warm, wet environmental conditions favour development of footrot, and under perfect conditions, it takes just 2-3 weeks from infection to manifestation of clinical signs. Affected sheep show lameness of various d...
Article
Over a period of 1 year, 270 isolates identified as Taxon 39 of Bisgaard were obtained from the nasopharynx of veal calves at 11 epidemiologically independent Swiss fattening farms. Two isolates from each farm and the Australian Taxon 39 reference strain BNO311 were further characterized by genetic and phenotypic methods. Phylogenetic analysis of 1...
Chapter
Fre.de.rik.sen'i.a. N.L. fem. n. Frederiksenia named in tribute to Wilhelm C. Frederiksen, a Danish microbiologist, for his contribution to research on Pasteurellaceae. Proteobacteria / Gammaproteobacteria / Pasteurellales / Pasteurellaceae / Frederiksenia The description of Frederiksenia is based on the characterization of 24 strains from five Eur...
Article
Full-text available
Introduction: Dichelobacter nodosus (D. nodosus) is the etiological agent of ovine footrot affecting mainly sheep worldwide, but also free-ranging wild ungulates such as Alpine ibex (Capra ibex ibex) and mufflon (Ovis orientalis orientalis). A nationwide ovine footrot eradication program is planned for the years to come, based on polymerase chain...
Article
Full-text available
Background Osteomyelitis is relatively frequent in young pigs and a few bacterial species have been postulated to be potential causative agents. Although Actinobacillus (A.) pleuropneumoniae has been sporadically described to cause osteomyelitis, typically, actinobacillosis is characterized by respiratory symptoms. Nevertheless, subclinical infecti...
Article
Full-text available
Human campylobacteriosis is the most prevalent zoonosis, with chicken meat contributing substantially to the number of cases. Measures to avoid or at least reduce exposure by meat contaminated with Campylobacter (C.) spp. are needed. With regard to the process hygiene criterion introduced in 2018 for Campylobacter spp. on broiler carcasses, we eval...
Chapter
Pas.teu.rel.la.ce'ae. N.L. fem. n. Pasteurella type genus of the family; ‐aceae suffix to denote a family; N.L. fem. pl. n. Pasteurellaceae the Pasteurella family. Proteobacteria / Gammaproteobacteria / Pasteurellales / Pasteurellaceae Members of the family Pasteurellaceae are Gram‐negative and nonmotile. They are negative for growth on Simmon's ci...
Chapter
Ne.crop.so.bac'ter. Gr. masc. n. nekros , dead body, corpse; Gr. fem. n. opsis , appearance, view; N.L. masc. n. bacter , a rod, N.L. masc. n. Necropsobacter , a rod isolated from an autopsy. Proteobacteria / Gammaproteobacteria / Pasteurellales / Pasteurellaceae / Necropsobacter The genus Necropsobacter includes taxa previously reported as the SP...
Article
Full-text available
Species of the bacterial genus Photorhabus live in a symbiotic relationship with Heterorhabditis entomopathogenic nematodes. Besides their use as biological control agents against agricultural pests, some Photorhabdus species are also a source of natural products and are of medical interest due to their ability to cause tissue infections and subcut...
Chapter
Ni.co.le.tel'la. N.L. fem. dim. n. Nicoletella named in tribute to Jacques Nicolet, a Swiss microbiologist, for his contribution to research on Pasteurellaceae. Proteobacteria / Gammaproteobacteria / Pasteurellales / Pasteurellaceae / Nicoletella Nicoletella is a monotypic genus in the family Pasteurellaceae as determined by a polyphasic approach u...
Article
Objectives: To describe multidetector CT and ultrasonographic characteristics of abdominal arterial pseudoaneurysms (segmental dilatations of an artery with a ruptured tunica intima) arising secondary to systemic mycosis in dogs. Materials and methods: Retrospective study on dogs with confirmed histological diagnosis of a fungal pseudoaneurysm a...
Article
Full-text available
A footbath-based control program for ovine footrot, a contagious disease caused by Dichelobacter nodosus, will be implemented in Switzerland. The currently used footbath disinfectants formaldehyde, zinc sulfate and copper sulfate are carcinogenic or environmental pollutants. Hence, the aim of this study was to identify alternative disinfectants, wh...
Article
'Treponema phagedenis' was originally described in 1912 by Noguchi but the name was not validly published and no type strain was designated. The taxon was not included in the Approved Lists of Bacterial Names and hence has no standing in nomenclature. Six Treponema strains positive in a 'T. phagedenis' phylogroup-specific PCR test were isolated fro...
Article
Full-text available
Background: Ovine footrot caused by Dichelobacter nodosus (D nodosus) is an infectious disease affecting sheep worldwide. Switzerland plans a nationwide footrot eradication program, based on PCR-testing of interdigital swab samples. The aim of this study was to test for the presence of D nodosus in clinically footrot-free sheep flocks which had be...
Preprint
Dichelobacter nodosus is a gram-negative fastidious anaerobic bacterium and the causative agent of ovine footrot. The disease has a global presence and is endemic in many countries. Clinical symptoms range from mild interdigital dermatitis in benign footrot to severe underrunning and separation of the hoof horn from the underlying tissue in virulen...
Preprint
Full-text available
Species of the bacterial genus Photorhabus live in a symbiotic relationship with Heterorhabditis entomopathogenic nematodes. Besides their use as biological control agents against agricultural pests, some Photorhabdus species are also a source of natural products and are of medical interest due to their ability to cause tissue infections and subcut...
Article
Full-text available
Abstract Mycoplasma hyopneumoniae and Mycoplasma hyorhinis are two phylogenetically related species colonizing the respiratory tract of pigs but differing in pathogenicity, the basis of which is not well resolved. We hypothesize that genes belonging to the species-specific portion of the genome and being non-essential during ideal laboratory growth...
Article
Mycoplasma (M.) hyopneumoniae is the etiological agent of enzootic pneumonia in pigs and is closely related to M. hyorhinis, which can be isolated from the healthy mucosal surfaces of the upper respiratory tract. In rare cases it can also cause arthritis and polyserositis. Since the innate immune system is an important first line of defense and pro...
Article
Mycoplasma hyopneumoniae causes enzootic pneumonia (EP) in swine, a disease related to high economic losses in production systems. Epidemiological spread of M. hyopneumoniae clones was studied by multi-locus sequence typing (MLST) in several swine production regions but so far not in South America. Using MLST, we have therefore investigated M. hyop...
Article
Introduction: Ovine footrot caused by Dichelobacter nodosus is a highly contagious and painful disease representing an economic as well as an animal welfare problem. In order to get more information on the infection dynamics, 26 lambs and 4 ewes enrolled in an in-contact infection trial were monitored over two weeks for the presence of D. nodosus-...
Article
Introduction: The aim of this study was to determine the prevalence of the three Treponema species as well as D. nodosus in Digital dermatitis (DD) and slurry of Swiss cattle using PCR. A total of 86 specimens from 24 farms were enrolled in the study. Slurry samples from 21 DD-affected and one unaffected farm were collected to assess the potential...
Article
Clinical outcomes compatible with digital dermatitis (DD) were observed in a second lactation, milking Mediterranean Buffalo (MB). The animal was sharing the free-stall with other 99 milking MBs separated by a fence from a pen harbouring 40 milking cross-breed dairy cows. The macroscopic lesion observed on the right, rear, limb was categorized as M...
Article
Full-text available
Bacterial symbionts are crucial for the infectivity and success of entomopathogenic nematodes as biological control agents. The current understanding of the symbiotic relationships is limited by taxonomic uncertainties. Here, we used whole-genome sequencing and traditional techniques to reconstruct the phylogenetic relationships between all describ...
Article
Footrot caused by Dichelobacter nodosus is a highly contagious bacterial disease affecting the claw of sheep and the main cause of lameness in these animals. It is not only an economic burden but also a serious animal welfare issue. More information about the transmission of D. nodosus is needed for effective footrot control programs. We therefore...
Article
Full-text available
Virulent ovine foot rot is a contagious foot disease. Given the development and validation of a real-time PCR to detect Dichelobacter nodosus isolates that contain the virulence-associated protease genes aprV2 and aprB2, the diagnosis of foot rot has made considerable progress. We evaluated pooling methods to reduce the number of samples during a f...
Article
Full-text available
Rodentibacter gen. nov. is proposed based on isolation and phenotypic characterization of strains, predominantly from rodents. The strains showed 86 % or higher rpoB gene sequence similarity and indicated a genus-level relationship within Pasteurellaceae. The strains compared at 16S rRNA gene sequence level showed 93.8 % or higher similarity, and t...
Article
Enzootic pneumonia (EP) in pigs caused by Mycoplasma (M.) hyopneumoniae has successfully been combatted in Switzerland. A control program was fully implemented in 2004 which is based on total depopulation strategies of affected fattening farms as well as partial depopulation on breeding farms. Thereby, the number of cases has dropped drastically fr...
Article
Human campylobacteriosis is a major public health concern in developed countries, with Campylobacter jejuni and Campylobacter coli from poultry recognized as the main source of human infection. Identification of Campylobacter-positive broiler herds before slaughter is essential for implementing measures to avoid carryover of pathogens via the slaug...
Article
Full-text available
Campylobacter jejuni along with C. coli are major cause of human gastroenteritis worldwide. So far, the human immune response against Campylobacter is not entirely clear. We hypothesize that it is coordinated by an interaction between pro-inflammatory and regulatory cytokines which is influenced by bacterial and host-individual differences. Accordi...
Data
Effect of person on cytokine production by LPS using One Way ANOVA. (DOCX)
Data
Correlation between the levels of IL-8, IL-6 and IL-10 following stimulation with the six strains of Campylobacter and LPS using Pearson Correlation coefficient. Each data point represents mean value stimulation of one person with the six strains of Campylobacter or LPS. P values ≤ 0.05 were considered significant. (TIF)
Article
Respiratory disorders in fattening pigs are of major concern worldwide. Particularly Enzootic Pneumonia remains a problem for the pig industry. This chronic respiratory disease is primarily caused by Mycoplasma hyopneumoniae (M. hyopneumoniae). However, more recently it was hypothesised that M. hyorhinis can also cause similar lung lesions. To inve...
Article
Full-text available
Splenitis is uncommonly reported in dogs. Herein, the authors describe its prevalence, clinical findings and outcomes, histologic patterns, and causes. Splenic samples of dogs diagnosed with splenitis between 2005 and 2013 were collected and stained with hematoxylin and eosin, Gram, green-Gram, Giemsa, periodic acid–Schiff, and Ziehl-Neelsen. Sampl...
Article
Full-text available
Background: Campylobacter fetus subspecies fetus (CFF) is an important pathogen for both cattle and humans. We performed a systematic epidemiological and clinical study of patients and evaluated the genetic relatedness of 17 human and 17 bovine CFF isolates by using different genotyping methods. In addition, the serotype, the dissemination of the...
Article
Mycoplasma hyorhinis is a common inhabitant of the upper respiratory tract and tonsils of pigs. Its role as a possible pathogen remains controversial. In order to gain more insight into the epidemiology and population structure of Mycoplasma hyorhinis we genetically characterized 60 isolates by multi locus sequence typing (MLST). The M. hyorhinis s...
Article
Full-text available
Species of the family Pasteurellaceae play an important role as primary or opportunistic, predominantly respiratory, pathogens in domestic and wild animals. Some of them cause severe disease with high economic losses in commercial animal husbandry. Hence, rapid and accurate differentiation of Pasteurellaceae is important and signifies a particular...
Article
Full-text available
SUMMARY Campylobacter jejuni and Campylobacter coli are the most important bacterial causes of human gastroenteritis. Chicken has been recognized as a major source for human infection, whereas cattle might also contribute to a lesser extent. However, there is a paucity of information available regarding Campylobacter in Swiss cattle and their role...
Article
Full-text available
To reinvestigate the taxonomy of [Actinobacillus] muris, 474 strains mainly from mice and rats were characterized by phenotype and 130 strains selected for genotypic characterization by 16S rRNA and partial rpoB gene sequencing. The type strain was further investigated by whole genome sequencing. Phylogenetic analysis of the DNA sequences showed on...
Article
Full-text available
A polyphasic taxonomic analysis was done on 11 uncommon Gram-negative, non-motile, catalase and oxidase positive but indole negative strains isolated from tortoises. Phenotypically and genetically they represented a homogenous group of organisms most closely related to but being distinct from Uruburuella suis. In the 16S rRNA gene tree they cluster...
Article
Mycoplasma hyopneumoniae is the major cause of enzootic pneumonia (EP) in domestic pigs, a disease with low mortality but high morbidity, having a great economic impact for producers. In Switzerland EP has been successfully eradicated, however, sporadic outbreaks are observed with no obvious source. Besides the possibility of recurrent outbreaks du...
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Article
Full-text available
Campylobacter jejuni is the most common food-borne zoonotic pathogen causing human gastroenteritis worldwide and has assumed more importance in Italy following the increased consumption of raw milk. Our objectives were to get an overview of genotypes and antibiotic resistances in C. jejuni isolated from milk, cattle feces, and pigeons in dairy herd...
Article
Full-text available
Polyphasic analysis was done on 24 strains of Bisgaard taxon 16 from five European countries and mainly isolated from dogs and human dog-bite wounds. The isolates represented a phenotypically and genetically homogenous group within the family Pasteurellaceae. Their phenotypic profile was similar to members of the genus Pasteurella. Matrix-assisted...