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PubMed2002

Prevalence and diversity of Arcobacter spp. isolated from the internal organs of spontaneous porcine abortions in Denmark.

A study was conducted to determine the prevalence and possible significance of campylobacteria in pig abortions in Denmark. Surface-cauterised liver and kidney samples from 55 aborted pig fetuses submitted to the Danish Veterinary Laboratory were taken and a sensitive isolation procedure used to examine pooled tissue samples for Campylobacter, Arcobacter and Helicobacter spp. Routine microbiological, immunological, and histopathological examinations were also performed to identify concurrent infections or histopathological changes. The abortions tested negative for established abortifacient pathogens (Brucella, Leptospira, PPV, PRRSV), but Arcobacter spp. were recovered from 23/55 abortions. Co-infections with Streptococcus suis, Escherichia coli, and haemolytic streptococci were observed in 7/23 Arcobacter-positive fetuses, and in 4/32 Arcobacter-negative fetuses. Histopathological analyses identified placentitis, pneumonia, hepatitis and encephalitis among the study group. However, no obvious pathologic features were solely associated with Arcobacter-positive cases, nor were Arcobacter-like bacteria observed in tissue samples. Protein profile analyses of the 27 Arcobacter isolates identified 11 as A. cryaerophilus and 10 as A. skirrowii. Six strains could not be classified into any existing species and were phenotypically distinct, thus, potentially representing at least one new species. The identification results showed that multiple taxa could be found in a single fetus, and in distinct aborted fetuses from a single sow. The high prevalence of arcobacters in Danish pig abortions may account for at least some of the >90% of cases in which no established abortifacient agent is detected, but further studies are needed to define the role of each species, especially where co-infections with other bacteria are present.

Abortion, Veterinary↗
PubMed2003

Nonprotein amino acids of plants: significance in medicine, nutrition, and agriculture.

Those nonprotein amino acids found in food and fodder plants and known to be toxic to man and domestic animals are described. These include toxins from many legume genera including Lathyrus, from other higher plant families, from seaweeds, and from fungi. Some inhibit protein synthesis, while others are incorporated into proteins with toxic effects. Basic processes such as urea synthesis and neurotransmission may be disrupted. The probable roles of nonprotein amino acids in protecting plants against predators, pathogens, and competing plant species are considered. The need to learn more of the nutritive value of nontoxic nonprotein amino acids and to explore the potential of others either as drugs or as leads to drugs in human and veterinary medicine is emphasized.

Agriculture↗
PubMed2005

[Prions--a challenge of Hygieia].

The history of Prion diseases goes further back than it appears at first sight. The first description was published in 1732. But not before the late 70s and early 80s of the last century the true nature of Scrapie in sheep was recognised. Only the huge outbreak of the bovine spongioforme encephalopathy (BSE) led to more detailed knowledge regarding the transmission of the new type of a pathogen agent.

Animals↗
PubMed2026

A set of genetic tools for use in Clostridioides difficile and related species.

The Clostridia are a phylogenetically diverse group of anaerobic, spore-forming bacteria that include species of medical, veterinary and industrial importance. The last two decades have seen major advances in our understanding of Clostridial biology despite the difficulties of anaerobic microbiology and the challenges associated with limited genetic tools. Effort has largely focused on the human pathogen Clostridioides difficile, but many of the methods developed have also proven useful in other species. Here, we present a collection of new genetic tools, including an array of promoters of varying strength, that we have characterized in C. difficile, the food spoilage bacterium Clostridium sporogenes and industrially important Clostridium saccharoperbutylacetonicum. We also present a set of modular plasmids that allow expression of proteins with a variety of tags, including for protein purification and fluorescence microscopy and a method for genetic barcoding of C. difficile to facilitate competitive index experiments. We make these tools available in the hope that they will prove useful to the community in support of our growing understanding of these important bacteria.

Clostridioides difficile↗
PubMed1975

Pathogenicity of a caprine herpesvirus.

A herpesvirus isolated from neonatal Angora kids (Capra hircus) with a relatively severe generalized infection was shown to be infective for adult goats as well as for kids. However, the virus lacked pathogenicity for either lambs or calves. Although a nonreciprocating serologic overlap exists between the caprine virus and the antibody to bovine herpesvirus (BHV-1), results of cross immunity tests in calves indicated that the 2 viruses are immunologically distinct. On the basis of these findings, the caprine virus seems to be a specific pathogen of goats. Accordingly, the designation of Herpesvirus caprae or caprine herpesvirus 1 seems taxonomically appropriate.

Abortion, Veterinary↗
PubMedDate not supplied

[Porcine reproductive and respiratory syndrome: ten years of experience (1986-1996) with this undesirable viral infection].

Porcine reproductive and respiratory syndrome (PRRS) is an infectious disease in swine that emerged 10 years ago. Today, PRRS is endemic in many if not all the pig-producing countries. The syndrome is due to a small enveloped RNA virus which belongs to the new Arteriviridae group. This group also includes the equine arterivirus and the simian hemorrhagic fever virus. The disease produces many clinical symptoms in pigs of any age but the two major features of the syndrome are respiratory and reproductive failure. An influenza-like illness is often observed consisting of a transient loss of appetite, slight hyperthermia and respiratory distress. The reproductive problems include late-term abortion, stillbirth and young piglet mortality. The virus is remarkably well adapted to its natural host. It infects almost exclusively pig monocytes or macrophages. For unexplained reasons, the virus may persist in the body for extended periods (several weeks) after an antibody immune response has been mounted. Within herds, the virus may persist for several years. In the acute phase of the infection, the immune functions of the pig may be impaired, however, a chronic immunosuppressive effect does not seem to occur thereafter. Several vaccines are available, which all have protective value against PRRS clinical disorders. None of them, however, has been tested for its ability to prevent or shorten the persistent infection in individual pigs or the long-term effect of virus circulation within herds. In the future, PRRS virus may be only an additional contaminant of farms with limited effects on profitability; however the possibility for this persistent infection to supply swine or eventually other species with new pathogenic variants must be also considered. This review provides a detailed description of the aetiology, pathology, immunology, diagnostic methods and epidemiology of PRRS.

Abortion, Veterinary↗
PubMedDate not supplied

[Zoonoses control--new challenges in health protection of consumers].

The eradication of bovine tuberculosis and brucellosis of domestic stock in Germany through the combined efforts of veterinary medicine, the agricultural section and the state was an historic achievement. Since the two diseases are zoonoses, their successful control can also be seen as a valuable contribution to public health. Both these zoonoses are classic animal diseases presenting themselves as clinical entities complete with gross pathological lesions. In contrast, today we are confronted with pathogens causing zoonoses characterised by latent, i.e. clinically inapparent herd infections that do not result in visible tissue changes. Nevertheless, through contaminated foodstuffs, these pathogens contribute to food-borne infections leading to the outbreak of genuine zoonoses in humans. It has been estimated that there could be as many as two million cases of food-borne infections annually in Germany. Among them are salmonellosis, campylobacteriosis, yersiniosis, infections with verotoxin producing E. coli, listeriosis and toxoplasmosis. While the national animal disease legislation only foresees the control of notifiable diseases, the basis for zoonoses control is laid down in the EU Zoonosis-Directive, which is presently awaiting its transposition into national law and into practice. In order, for instance, to combat the most important Salmonella infections of humans, Integrated Quality Systems (IQS) have been formulated as a means of implementing the proven HACCP concept in animal production units and ensuring animal health from the point of view of consumer protection. The aim of all measures must be to free infected herds of pathogens, to investigate and eliminate all sources with a potential for further pathogen introductions, to maintain pathogen-free herds--with a reduced pathogen challenge in mid-term time periods--, as well as to develop diagnostics capable of identifying pathogen carriers before slaughter. For the disinfection of stock, it is important to have epidemiological data collecting systems and information systems that allow complete diagnostic tracing from herd to slaughterhouse and vice versa. All sides, including research and surveillance, as well as producers are called upon to actively share in protecting the health of consumers as far as it is threatened by latent infections in domestic stock.

Animals↗
PubMed2006

Veterinary and medical aspects of abortion in Danish sheep.

The Danish sheep population totals around 144,000 animals, but little is known of the causes and prevalance of diseases. This study focuses on the causes of abortion in Danish sheep. During one breeding season, aborted foetuses and stillbirths with signs of intrauterine death or malformation were submitted for laboratory examination from a population of 3,758 breeding ewes. Samples from 24 incidents of abortion and 21 ewes delivering malformed lambs or lambs with ante partum decomposition were submitted. A specific aetiology was established in 66.7% and 14.3% of the cases, respectively. Bacterial pathogens were the most prevalent cause of abortion. Several of the abortifacients were zoonotic microorganisms, for example Listeria monocytogenes, Campylobacter fetus subsp. fetus, Yersinia pseudotuberculosis and Toxoplasma gondii. The identified microorganisms probably represent the most common causes of abortion in Danish sheep but occurrence in Denmark of other pathogens such as Coxiella burnetii and Chlamydophila abortus cannot be excluded. Due to the high prevalence of zoonotic microorganisms, precautions must be taken in handling abortions or assisting lambing, especially for pregnant women.

Aborted Fetus↗
PubMed2001

Modulation of host immunity by haematophagous arthropods.

The medical and veterinary public-health importance of haematophagous arthropods is immense and continuing to increase because of the emergence of new vector-borne infectious agents and the resurgence of well known ones. Control of blood-feeding arthropods and the pathogens they transmit is compounded by drug, insecticide and acaricide resistance. Novel control strategies are needed. Immunological control is one very promising approach to these problems. In order to develop anti-arthropod vaccines that block pathogen transmission and establishment, the immunological interactions occurring at the interface of the blood-feeding arthropod and host must be characterized. An important component of these interactions is arthropod modulation of the host's innate and acquired, specific immune defences. This review discusses current knowledge regarding the ability of haematophagous arthropods to alter their hosts' immune defences, the impact of those changes on pathogen transmission, the molecular bases for the immunomodulation, and strategies for identification of the molecules in arthropod saliva that are responsible for the immunomodulation.

Animals↗
PubMed2006

[Antibioresistance of Escherichia coli strains isolated from raw chicken meat in Senegal].

INTRODUCTION: Antimicrobial-resistant Escherichia coli and others pathogens bacteria can be transferred from animals to humans through consumption of contaminated food and foods products and thus present a public health risk. The increase in E. coli resistance to commonly used antimicrobials both in the public health and veterinary sectors is one of the major threats of health care worldwide. The present study was undertaken to estimate the antimicrobial resistance of E. coli isolates from raw chicken meat in Dakar. MATERIAL AND METHOD: Levying of skin and muscle have been carried out on 120 chicken carcasses bought from 13 sale points and 23 flocks beetween November 2003 and April 2004. 102 Escherichia coli strains have been isolated, among which, 90 were tested for their susceptibilities to 16 selected antibiotics by agar diffusion method. RESULTS: All Escherichia coli strains (100%), were resistant to one or more antibiotic; 60 strains (66.66%) being resistant to more than five antibiotics. Those frequently encountererd are: ampicillin, trimethoprim, trimethoprim-sulfametoxazole, tetracycline, sulfonamides, streptomycin, nalidixic acid. Multiple resistances to 12 antibiotics were also observed. The lowest resistances were noted with gentamicin (3.33%) and neomycin (5.56%). CONCLUSION: This study showed the significance of chicken meat as source of Escherichia coli strains with a simple or multiple resistance to various antibiotics tested. Further studies are necessary in order to determine bacterium mechanisms of resistance.

Animals↗
PubMed1991

Brucella abortus-associated meningitis in aborted bovine fetuses.

Granulomatous meningitis was present in 6/33 bovine fetuses from which Brucella abortus (B. abortus) had been isolated. Meningitis was severe in three fetuses, moderate in one fetus, and mild in the remaining two fetuses. The meningitis was characterized by the infiltration of a mixed population of lymphocytes, plasma cells, and macrophages in the leptomeninges. Vasculitis characterized by the infiltration of lymphocytes and plasma cells in the vascular wall was observed in the vessels of the cerebral cortices of 4/6 fetuses. Gram negative coccobacilli were present in the cytoplasm of the leptomeningeal macrophages and extracellularly. Brucellar antigens labeled by the avidin-biotin-peroxidase complex method were present in massive amounts in leptomeningeal macrophages and in small foci of stained cells in the choroid plexus and ependyma. The findings indicate that B. abortus is one of pathogens capable of inducing meningitis in bovine fetuses.

Abortion, Veterinary↗
PubMed1997

[Significance of causes of infectious abortion in sheep flocks in northern Baden-Württemberg with special reference to Chlamydia psittaci].

Investigations on the reasons of infectious abortion cases in sheep flocks in northern parts of Baden-Wuerttemberg eludicate the wide-spreading of Chlamydia psittaci (C. psittaci) and its significance as the most frequent cause of abortions in sheep. Another important pathogen agent causing abortions is Salmonella abortus ovis (S. abortus ovis) which could be demonstrated by using a serological ELISA test. A less important role than C. psittaci and S. abortus ovis plays Coxiella burnetii in abortion of sheep. A high prevalence of Toxoplasma gondii and border disease infections in sheep flocks could be revealed by serological studies, too. Statistical evaluations of the obtained results demonstrate a significantly increased number of positively reacting female sheep in flocks suffering from abortions in comparison to those deriving from flocks devoid of abortion cases. Serological studies on leptospirosis and brucellosis exclude a participation of these pathogen agents in abortion cases in the investigated flocks at present. The significance of zoonosis originated from sheep is emphasized.

Abortion, Veterinary↗
PubMed1999

Molecular epidemiological studies of veterinary arboviral encephalitides.

Recent studies using molecular genetic approaches have made important contributions to our understanding of the epidemiology of veterinary arboviral encephalitides. Viruses utilizing avian enzootic hosts, such as Western equine encephalitis virus (WEEV) and North American Eastern equine encephalitis virus (EEEV), evolve as relatively few, highly conserved genotypes that extend over wide geographic regions; viruses utilizing mammalian hosts with more limited dispersal evolve within multiple genotypes, each geographically restricted. Similar findings have been reported for Australian alphaviruses. This difference may be related to vertebrate host relationships and the relative mobility of mammals and avians. Whereas EEEV and Venezualan equine encephalitis virus (VEEV) utilize small mammalian hosts in the tropics, most WEEV genotypes probably utilize avian hosts in both North and South America. The ability of mobile, infected avian hosts to disperse alphaviruses may result in continual mixing of virus populations, and thus limit diversification. This high degree of genetic conservation is also exhibited by EEE and Highlands J viruses in North America, where passerine birds serve as amplifying hosts in enzootic transmission foci. Most equine arboviral pathogens, including EEEV, WEEV and Japanese encephalitis virus (JEV), occur in a naturally virulent enzootic state and require only appropriate ecological conditions to cause epizootics and epidemics. However, VEE epizootics apparently require genetic changes to convert avirulent enzootic strains into distinct epizootic serotypes. All of these arboviruses have the potential to cause severe disease of veterinary and human health importance, and further molecular epidemiological studies will undoubtedly improve our ability to understand and control future emergence.

Alphavirus↗
PubMed1987

A necrotizing pneumonia in lambs caused by pseudorabies virus (Aujesky's disease virus).

An outbreak of pseudorabies occurred in sheep housed with swine in the same building. Although the sheep and swine were not in physical contact, the lambs and ewes were exposed to air from the sows' section. Three dead lambs were submitted to the Iowa State University Veterinary Diagnostic Laboratory for necropsy. Grossly there were pulmonary congestion and multifocal pulmonary hemorrhages. Microscopic lesions were severe acute multifocal necrotizing bronchopneumonia with necrotizing vasculitis and intranuclear inclusion bodies within the neurons of the parabronchial ganglia. Bacterial cultures were negative for pathogenic agents; pseudorabies virus was isolated from ovine brain tissue. Viral antigen was demonstrated in the neurons of the parabronchial ganglia by immunoperoxidase staining. Electron microscopy revealed nucleocapsids in the parabronchial ganglionic neurons which contained basophilic intranuclear inclusion bodies. Viral DNA prepared from the ovine pseudorabies virus isolate was found by restriction endonuclease analysis to be related to the Indiana Funkhauser strain of pseudorabies virus.

Animals↗
PubMed1998

The specter of glycopeptide resistance: current trends and future considerations.

Two glycopeptide antibiotics, vancomycin and teicoplanin, are currently available for clinical use in various parts of the world, whereas a third, avoparcin, is available for use in agricultural applications and in veterinary medicine in some countries. Because of their outstanding activity against a broad spectrum of gram-positive bacteria, vancomycin and teicoplanin have often been considered the drugs of "last resort" for serious infections due to drug-resistant gram-positive pathogens. Glycopeptides had been in clinical use for almost 30 years before high-level resistance, first reported in enterococcal species, emerged. More recently, there have been disturbing reports of low- and intermediate-level resistance to vancomycin in strains of Staphylococcus aureus. A review of earlier reports reveals, however, that S. aureus strains with reduced susceptibility to glycopeptides were first identified >40 years ago. Such strains may occur in nature or may have developed low-level mutational resistance in response to the selection pressure of glycopeptide therapy. Of considerably greater concern is the possibility that vancomycin resistance genes found in enterococci may be transferred to more virulent organisms such as staphylococci or Streptococcus pneumoniae.

Anti-Bacterial Agents↗
PubMed1991

Bacteriological investigations of clinical mastitis in heifers in Sweden.

Bacterial analyses were carried out of 2069 udder secretions, isolated from 1481 heifers with mastitis in eight veterinary districts in Sweden. Streptococci, e.g. Streptococcus dysgalactiae and Str. uberis, dominated the bacterial flora, being isolated from 34.4 and 19.5% respectively of heifers with clinical mastitis occurring from puberty up to 14 d post partum. Bacterial species generally regarded as important pathogens in the summer mastitis complex, e.g. Actinomyces pyogenes, Stuart-Schwan coccus and strictly anaerobic bacteria such as Peptostreptococcus indolicus, Fusobacterium necrophorum and Bacteroides melaninogenicus were isolated at low frequencies (13.2, 6.3, 9.4, 3.8 and 1.3% respectively). When the cases of mastitis studied were restricted to those appearing in heifers pre partum, May 15 to October 14 (summer mastitis), these bacterial species were isolated at higher percentages (27.1, 14.4, 21.4, 13.5 and 5.2% respectively). These figures were, nevertheless, still lower than those published in reports from other countries. Whether considered up to 14 d post partum or only pre partum, there were no significant differences in the frequencies of A. pyogenes isolated at different seasons. There were geographical differences in bacterial incidence, e.g. Staphylococcus aureus was isolated significantly more often in northern regions whereas Str. dysgalactiae was more common in the south. This and other Swedish investigations support the theory that A. pyogenes and strictly anaerobic bacteria are 'secondary invaders' that depend on Str. dysgalactiae to cause a primary infection. It is stressed that the udders of all heifers should be examined daily so that cases of mastitis can be treated immediately.

Animals↗
PubMed2005

Foodborne general outbreaks of Salmonella Enteritidis phage type 4 infection, England and Wales, 1992-2002: where are the risks?

Foodborne outbreaks of Salmonella enterica serovar Enteritidis phage type 4 (PT4) infection (n=497), reported to the Health Protection Agency Communicable Disease Surveillance Centre between 1992 and 2002, were compared with other pathogens (n=1148) to determine factors (season, setting, food vehicles, food safety faults) associated with this pathogen. Logistic regression was applied to control for potential confounding. Foodborne general outbreaks of S. Enteritidis PT4 infection were more likely to occur in the spring and summer, and were more often linked to schools, private residences and residential institutions. Eggs, egg products and the use of raw shell egg were strongly associated with this pathogen. Most outbreaks were linked to cross-contamination and inadequate heat treatment. This paper describes the decline in the S. Enteritidis PT4 epidemic, providing evidence that control measures introduced, e.g. improved biosecurity and vaccination, have worked. Continued surveillance of human and veterinary salmonellosis is essential to detect future problems.

Disease Outbreaks↗
PubMed2000

Cost-effective antimicrobial drug selection for the management and control of respiratory disease in European cattle.

Respiratory disease in growing cattle has both animal welfare and economic implications, but the use of antimicrobial drugs to treat and control it is under public scrutiny owing to concerns that their use in food-producing animals may be detrimental to human health. This paper outlines criteria for the selection of appropriate and cost-effective drugs, based on good dinical practice and sound economic principles. It also suggests that these principles should be integrated into quality assurance schemes, and that the monitoring of antimicrobial resistance patterns among known bacterial respiratory pathogens should be improved.

Animals↗