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Clinical and environmental isolates of Cryptococcus gattii from Australia that retain sexual fecundity.

Cryptococcus gattii is a primary pathogenic yeast that causes disease in both animals and humans. It is closely related to Cryptococcus neoformans and diverged from a common ancestor approximately 40 million years ago. While C. gattii has a characterized sexual cycle dependent upon a dimorphic region of the genome known as the MAT locus, mating has rarely been observed in this species. In this study, we identify for the first time clinical (both human and veterinary) and environmental isolates from Australia that retain sexual fecundity. A collection of 120 isolates from a variety of geographic locations was analyzed for molecular type, mating type, and the ability to develop mating structures when cocultured with fertile tester strains. Nine isolates produced dikaryotic filaments with paired nuclei, fused clamp connections, and basidiospores. DNA sequence analysis of three genes (URA5, the MATalpha-specific SXI1alpha gene, and the MATa-specific SXI2a gene) revealed little or no variability in URA5 and SXI2a, respectively. However across the 108 MATalpha strains sequenced, the SXI1alpha gene was found to exist as 11 different alleles. Phylogenetic analysis found most variation to occur in the more fertile genotypes. Although some lineages of Australian C. gattii have retained the ability to mate, the majority of isolates were sterile, suggesting that asexuality is the dominant mode of propagation in these populations.

Alleles↗

Canine coronavirus infections in Japan: virological and epidemiological aspects.

Ten strains, eight field and two reference laboratory strains, of canine coronavirus (CCV) were comparatively examined with respect to antigenic relationships and pathogenic potential in dogs. With monoclonal antibodies and hyperimmune antisera to feline coronavirus and CCV, respectively, varying degrees of antigenic diversities were found among the strains by neutralization and immunofluorescence assays, but it was felt that they belong to one serotype. Specific-pathogen-free puppies experimentally inoculated with some CCV strains manifested clinical symptoms, but there was a difference in their virulence. In order to elucidate the prevalence of CCV infections in dogs in Japan, we tested for neutralizing antibodies to CCV in 467 field dogs, and found a prevalence of 44.1%. Moreover, by using nested reverse transcriptase-polymerase chain reaction on rectal swabs of 100 diarrheic dogs recently presented in veterinary clinics, evidence of CCV in 16% of these specimens was found. The results suggested that CCV infection is more widespread than expected in dogs, and that CCV is a significant etiologic factor in canine diarrhea also in Japan.

Animals↗

[Considerations on the sense and nonsense of sensitivity determinations for veterinary practice].

The parameter most frequently used as a basis for antibiotic therapy is the minimum inhibitory concentration (MIC). This is a valid, standardised and comparative parameter for evaluating the effectiveness of a drug under laboratory conditions. The results of this test are considerably affected by changes in the standard laboratory conditions, which differ widely from the varying in vivo situations. The most common methods used in sensitivity testing, which are based on MIC values and pharmacokinetic data are discussed. The minimum antibiotic concentration (MAC) is much less affected by laboratory manipulations than is the MIC. The MAC is the lowest concentration having a barely measurable effect on the bacterium, whatever method is used. Although the MAC has not yet been standardised, it is a very informative test. The MAC is usually much lower than the MIC and it clearly shows that the MIC is an underestimation of antibacterial activity, particularly in animals with a reasonably functioning natural resistance. However, antimicrobial therapy should not be evaluated by microbiological and pharmacological methods alone, but also by clinical parameters, as the clinical response to antibacterial treatment may be influenced by many factors, which cannot be calculated as yet. Until he or she initiates treatment, particularly in life-threatening situations, a veterinary practitioner cannot wait for laboratory results. However, by carefully evaluating the clinical symptoms, and as a result of training and experience, he or she should be able to determine the causative organism in the majority of cases. Making and evaluating Gram-stained smears may be extremely helpful. The species of the suspected causative organism will suggest the antibiotic treatment of choice. Prospective sensitivity testing and resistance monitoring of pathogenic bacterial species, which may readily become resistant, at regular intervals is likely to be more effective, than culturing and testing alone in the event of failure of therapy.

Animals↗

Caprine mycoplasmosis: an outbreak of mastitis and arthritis requiring the destruction of 700 goats.

An acute outbreak of mastitis and arthritis in a herd of 700 goats required the destruction of all but the few animals that were held for observation. The milk of nearly all of about 400 lactating does contained almost pure cultures of Mycoplasma putrefaciens with counts in 150 samples up to 1 X 10(9) colony forming units/ml. At post mortem examination the joints of both the adults and kids contained a fibrinopurulent discharge. M putrefaciens was isolated in pure cultures and large numbers from joints, tissues and fluid not previously known to harbour this mycoplasma: brain, kidneys, lungs, lymph nodes, uterus and urine. The outbreak was milkborne and initiated by infusion of the pathogen into the teat canal by poor hygiene in the milking parlour and by feeding raw colostrum to kids. All but 12 of the herd of 700 goats were killed or sold for slaughter.

Abortion, Veterinary↗

Some microbiological aspects of inedible rendering processes.

Various aspects of the bacteriology of inedible rendering have been investigated in order to establish a solid basis for future decisions concerning an up-to-date and flexible legislation on rendering. Thermal death (TD)-graphs for spores of B. cereus and Cl. perfrigens, PA 3679 (Fig. 3), and heat transmission equations for animal tissues have been determined. By using the heat transmission data for bones and the TD graphs for the spores it is possible to predict the decimal reductions of spores in the centre of the largest pieces present during a given rendering process, thus establishing conditions for bacteriological safe processes. The calculations show that predrying for 45 min followed by cooking at 125 degrees C for 15 min and final drying ensures destruction of non-sporeforming bacteria and Bacillus anthracis spores even in the centre of 70 mm bone particles while heat resistant spores of clostridia are virtually unaffected. By reducing the particle size to less than 40 mm, the same process will result in a reasonable reduction of heat resistant clostridia spores, too (Table 4). In order to verify such theoretically calculated effects a new technique has been developed in which steel tubes containing a paste inoculated with spores were inserted in bones. These were treated in a cooker, were caught during discharge and examined. The results confirmed the calculations (Table 5). Most modern rendering systems (Carver-Greenfield, Stork-Duke, Wet Pressing) are continuous without pressure cooking and a common feature is a fine mincing minimizing the problem of heat penetration. In order to obtain information regarding the thermal sterilizing effect in such systems investigations were made in a pilot cooker using inoculated meat-and-bone meal mixed with water and/or fat. Regardless of whether fat was added or not sterility was found for samples containing water when the temperature during drying reached 110-120 degrees C, whereas cooking in fat only drastically increased the heat resistance of spores of both strains. Sterility was only obtained at temperatures of the order of 140 degrees C, a fact of minor importance for rendering, where thermal treatment usually takes place with moisture present. The decimal reductions actually found were compared to calculated ones and the former were all substantially higher than the latter (Table 6). Thorough investigation of sterilization in the wet pressing system has confirmed the conclusion that inactivation of pathogenic microorganisms during drying is obtained when temperatures reach 110 degrees C (Table 7 and 8).(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Feed↗

Laboratory diagnostic tests for retroviral infections in dairy and beef cattle.

Detection of bovine retroviruses stretches our diagnostic creativity to its limits. The nucleic acid-based, PCR-amplified assays are finding increased clinical use as the veterinary and livestock industry seek earlier detection of infection for eventual corrective management decisions. We are evolving from a point of disease diagnosis by tumor identification through conventional histopathology, to molecular diagnostics for early identification of retroviral nucleic acid (provirus). The clinical use of antibody-based assays lies in the simplicity of testing large numbers of animals, the relative sensitivity of the assays, and the low cost of testing. Although the pathogenicity of bovine leukemia virus (BLV) for cattle has been well documented, the disease potential for bovine immunodeficiency-like virus (BIV) for cattle is still being determined. Nevertheless, pressure to test for retroviral infections of livestock and, when feasible, removal of these infected animals from the herd will be increased.

Animals↗

Risk factors for antibiotic resistance in Campylobacter spp. isolated from raw poultry meat in Switzerland.

BACKGROUND: The world-wide increase of foodborne infections with antibiotic resistant pathogens is of growing concern and is designated by the World Health Organization as an emerging public health problem. Thermophilic Campylobacter have been recognised as a major cause of foodborne bacterial gastrointestinal human infections in Switzerland and in many other countries throughout the world. Poultry meat is the most common source for foodborne cases caused by Campylobacter. Because all classes of antibiotics recommended for treatment of human campylobacteriosis are also used in veterinary medicine, in view of food safety, the resistance status of Campylobacter isolated from poultry meat is of special interest. METHODS: Raw poultry meat samples were collected throughout Switzerland and Liechtenstein at retail level and examined for Campylobacter spp. One strain from each Campylobacter-positive sample was selected for susceptibility testing with the disc diffusion and the E-test method. Risk factors associated with resistance to the tested antibiotics were analysed by multiple logistic regression. RESULTS: In total, 91 Campylobacter spp. strains were isolated from 415 raw poultry meat samples. Fifty-one strains (59%) were sensitive to all tested antibiotics. Nineteen strains (22%) were resistant to a single, nine strains to two antibiotics, and eight strains showed at least three antibiotic resistances. Resistance was observed most frequently to ciprofloxacin (28.7%), tetracycline (12.6%), sulphonamide (11.8%), and ampicillin (10.3%). One multiple resistant strain exhibited resistance to five antibiotics including ciprofloxacin, tetracycline, and erythromycin. These are the most important antibiotics for treatment of human campylobacteriosis. A significant risk factor associated with multiple resistance in Campylobacter was foreign meat production compared to Swiss meat production (odds ratio = 5.7). CONCLUSION: Compared to the situation in other countries, the data of this study show a favourable resistance situation for Campylobacter strains isolated from raw poultry meat produced in Switzerland. Nevertheless, the prevalence of 19% ciprofloxacin resistant strains is of concern and has to be monitored. "Foreign production vs. Swiss production" was a significant risk factor for multiple resistance in the logistic regression model. Therefore, an adequate resistance-monitoring programme should include meat produced in Switzerland as well as imported meat samples.

Animals↗

Autogenous vaccines: the legal basis and regulation in the United Kingdom.

The Veterinary Medicines Directorate is the competent authority in the U.K. for ensuring the quality, safety and efficacy of veterinary medicinal products placed on the market. The Immunologicals team is responsible for the assessment of immunological applications for Marketing Authorisations and the Inspection of manufacturing sites that produce them. In addition to these activities, the team is also responsible for the assessment of applications for emergency product licences (autogenous vaccines) and the inspection of the facilities to manufacture them. These licences authorise the manufacture of inactivated vaccines, which are manufactured from pathogens obtained from an animal or animals from a holding and used for the treatment of the animals in that holding.

Government Regulation↗

Salmonella in pigs and animal feeding stuffs in England and Wales and in Denmark.

A comparison has been made between the incidence of salmonellas in pigs and feeding stuffs in England and Wales and in Denmark. In Denmark there is veterinary legislation requiring the sterilization of imported and home produced feed ingredients of animal origin. There is no such legislation in England and Wales. In Denmark 0.3% of resterilized imported meat and bone meal was contaminated with salmonellas. This compared with 23% of meat and bone meal in England and Wales and 20-27% of other ingredients of animal origin. In England and Wales salmonellas were isolated from 7% of caecal samples and 6% of lymph node samples, while in Denmark they were isolated from 3% of caecal samples and 4% of lymph node samples. In England and Wales 25 serotypes were found in both pigs and feeds and these included nearly all the most prevalent human pathogens. In Denmark four of the six serotypes in pigs had been found in resterilized feed. One notable difference between the two studies was the very wide range of serotypes found in pigs in England and Wales and the narrow range in Denmark. A second was that Salmonella typhimurium formed 15% of all Salmonella strains isolated from pigs in England and Wales, and 60% of those in Denmark.It is concluded that sterilization of animal raw ingredients in Denmark has reduced pig infections with types other than S. typhimurium that are found in England and Wales, but not with S. typhimurium. It is possible that this is because S. typhimurium once introduced into pigs is able to establish itself more easily than other serotypes.

Animal Feed↗

Spread of Coxiella burnetii infection in a flock of sheep after an episode of Q fever.

In October 1998, two abortions associated with Coxiella burnetii occurred in a group of 34 pregnant ewes in the sheep flock belonging to INRA Tours-Nouzilly. The flock was kept in groups of approximately 40 ewes, which were housed together in the same accommodation. The prevalence of C burnetii infection in the groups was investigated by using ELISA and PCR tests, which revealed a high prevalence of C burnetii. The ewes were treated with oxytetracycline to reduce the shedding of C burnetii and to prevent further abortions. Nevertheless, five abortions attributed to C burnetii occurred in January and March 1999 in three groups of ewes, and 24 of the ewes still shed the bacteria into their vaginal tracts. In addition, a serological study was carried out during the first year of life of the female lambs born in 1999 and 2000; 12 per cent of 113 lambs born in 1999 were seropositive for C burnetii by ELISA, and half of the ELISA-positive lambs were born either to serologically positive ewes or to dams that excreted the pathogen into their vaginal tracts. However, all the 150 lambs born in 2000 were ELISA-negative, suggesting that the preventive measures undertaken had suppressed both the abortions and the shedding of C burnetii, and reduced the transmission of the agent.

Abortion, Veterinary↗

The challenge of antibiotic resistance: need to contemplate.

"Survival of the fittest " holds good for men and animals as also for bacteria. A majority of bacteria in nature are nonpathogenic, a large number of them, live as commensals on our body leading a symbiotic existence. A limited population of bacteria which has became pathogenic was also sensitive to antibiotics to begin with. It is the man made antibiotic pressure, which has led to the emergence and spread of resistant genes amongst bacteria. Despite the availability of a large arsenal of antibiotics, the ability of bacteria to become resistant to antibacterial agents is amazing. This is more evident in the hospital settings where the antibiotic usage is maximum. The use of antibiotics is widespread in clinical medicine, agriculture, aquaculture, veterinary practice, poultry and even in household products. The major reason for this is the inappropriate use of antibiotics due to a lack of uniform policy and disregard to hospital infection control practices. The antibiotic cover provided by newer antibiotics has been an important factor responsible for the emergence of multi-drug resistant bacteria. Bacterial infections increase the morbidity and mortality, increase the cost of treatment, and prolong hospital stay adding to the economical burden on the nation. The problem is further compounded by the lack of education and " over the counter " availability of antibiotics in developing countries. Antibiotic resistance is now all pervasive with the developed world as much vulnerable to the problem. Despite advancement in medical technology for diagnosis and patient care, a person can still die of an infection caused by a multi-drug resistant bacteria. It is time to think, plan and formulate a strong antibiotic policy to address the burgeoning hospital infection.

Animals↗

Role of Salmonella arizonae and other infective agents in enteric disease of lambs.

Fecal samples from 545 diarrheic lambs on 12 ranches in southern Idaho and western Montana were examined for potential enteric pathogens. On 3 of the 12 ranches, enterotoxigenic Escherichia coli, Salmonella typhimurium, or S dublin was implicated as the etiologic agent. Rotavirus and coronavirus were identified on 1 ranch and rotavirus alone on another. Salmonella arizonae serotype 26:30 was isolated from the feces of diarrheic lambs on 6 of the 12 ranches in this study. Pregnant ewes from 1 of the 6 ranches in which S arizonae was enzootic were transported to the Montana Veterinary Research Laboratory and studies on S arizonae were conducted in lambs from these ewes. Salmonella arizonae was shown to elaborate an enterotoxin, the activity of which was reduced when assayed in the gut loop test, using lambs from ewes vaccinated with an S arizonae 26:30 bacterin. Oral challenge inoculation of 22 young colostrum-fed lambs with S arizonae 26:30 failed to produce any significant enteric disease, in contrast to oral challenge inoculation with S. oranienburg which resulted in death, with severe diarrhea and dehydration, in 4 of 6 lambs tested. Salmonella arizonae serotype 26:30 appears to be well adapted to the ovine host and may not be a significant cause of diarrheal disease on ranches where it is enzootic.

Animals↗

Importance in France of the infestation by Dirofilaria (Nochtiella) repens in dogs.

The presence of Dirofilaria repens has been mentioned in Europe, in Africa and in Asia, in different carnivores (dogs, foxes, cats, lions). In Europe the nematode has been reported in dogs, cats and foxes and the countries concerned by native cases are Italy, Spain, Greece, Yugoslavia and France. In France, until now, D. repens has been described, among animals, only in dogs. The first undoubted report dates back to 1953. Later, the prevalence was studied through widespread surveys (1986-1988-1989), focal surveys within some canine populations (military dogs) and some sporadic and fortuitous descriptions. The prevalence has been mainly assessed by pointing up the microfilariae in the blood and by identifying it after histochemical staining (for demonstration of the somatic distribution of acid phosphatase activity). The infestation rate was higher than 20% in some military dog populations. The cases occurred in nineteen French departments (Alpes-de-Haute-Provence, Aude, Bouches-du-Rhône, Corrèze, Corse, Dordogne, Gard, Gers, Gironde, Haute-Garonne, Loir-et-Cher, Nièvre, Pyrénées-Orientales, Rhône, Tarnet-Garonne, Var, Vaucluse, Vienne and Region Parisienne). The pathogenicity which is normally denied has to be reconsidered. The pathology of adult worms has not been clearly proved in dogs but the embolized microfilariae can bring about skin troubles. The potential pathogenicity, the necessity of the differentiation with D. immitis and above all, the zoonotic importance of D. repens must lead to search for it more often and to consider it with great interest.

Animals↗

Use of antimicrobials in wound management.

Antimicrobial medication should be considered an adjunct to the general care of wounds rather than a substitute for lavage, drainage, or other physical care intended to promote healing. Judicious use is based on results of diagnostic procedures and the professional judgment of the attending veterinarian. Organisms that contaminate or infect wounds of horses are similar to those that can affect human patients, such that personal hygiene and protection are important when caring for these equine patients, because attendants can easily be exposed to them. Although those organisms are considered to be ubiquitous, the inoculum that may be present on or in an infected wound may be substantially greater than that encountered during other daily activities of the veterinarian. Proper disposal of the bandage materials and personal protective clothing is important. Bacterial resistance is one of many "survival tactics" of bacteria and has been an important clinical consideration for physicians and veterinarians since antimicrobial drugs were discovered. Controversies and insufficient understanding of bacterial resistance abound, however. The entirety of the subject is beyond the scope of this article, but it is important to the veterinary profession and for the formulation of wound management in horses. We and our animal patients live in a world populated by microbial organisms of various types. Resistance among bacteria is likely to continue to be a clinical consideration in the future as it has been during the past 60 to 70 years. As veterinarians, we must recognize the zoonotic nature of resistance and implement biosecurity procedures to protect ourselves, other people in contact with those pathogens, and our patients. We must also recognize the merits of judicious targeted use of antimicrobial drugs and apply appropriate principles during the course of professional care for the well-being of our animal patients.

Animals↗

Isolation and identification of mycobacteria from porcine tissues: a three-year summary.

Mycobacteria were isolated from 1,591 (78%) of 2,036 porcine tissues submitted to Veterinary Services Laboratories over a 3-year period (July 1, 1971, to June 30, 1974). The isolates were identified by biochemical and serologic tests. Of the 1,547 Mycobacterium avium isolates, 452 were serotype 1, 728 were serotype 2, 60 were serotyped 4, 110 were serotype 8, and 51 were serotyped 10; 36 isolates represented 11 other serotypes; 65 isolates shared antigens with more than one serotype; and 45 isolates, untypabley serologic methods, were identified by pathogenicity in chickens as M avium. Mycobacterium bovis was isolated from 15 tissues; Mycobacterium fortuitum, from 3; and Mycobacterium paratuberculosis, Mycobacterium scrofulaceum, and Mycobacterium xenopi were each isolated from single specimens.

Animals↗

Typing of Listeria monocytogenes isolates by random amplification of polymorphic DNA.

BACKGROUND & OBJECTIVES: Listeria monocytogenes is an important food-borne pathogen causing meningitis and septicaemia in newborns and immunocompromised persons, abortion and preterm labour in pregnant women. Though various methods are available for typing L. monocytogenes, RAPD analysis has been used for epidemiological purposes in developed countries due to its greater discriminating ability. However, as there are no published reports from India on the typing of L. monocytogenes by RAPD technique the present study was undertaken to type isolates of L. monocytogenes from clinical, food and veterinary samples. METHODS: Isolates of L. monocytogenes were subjected to RAPD using four decamer random primers R1, R2, R3 and R4. Amplified products were analysed by agarose gel electrophoresis. RESULTS: Eight strains of L. monocytogenes on RAPD analysis generated 4 distinct profiles each with R1 and R4 primers and 3 different profiles with R2 and R3 primers. The isolates from fish, clinical and veterinary samples showed different profiles with respect to each other. Isolate from flat fish (serovar 4) showed a different profile from that of clams (serovar 1). Two isolates from placenta (serovar 1) showed similar profiles and all the isolates from veterinary samples generated similar profiles. INTERPRETATION & CONCLUSION: RAPD analysis in the present study allowed discrimination of isolates among the same serotype but from different sources. Since RAPD is a rapid technique and offers greater discrimination of strains, this method may be used for typing L. monocytogenes in India.

Animals↗

The equine herpesviruses.

Two viruses, EHV-1 and EHV-4, are now known to be responsible for disease conditions formerly considered caused by "equine rhinopneumonitis virus." Although these viruses share several laboratory and clinical features, they differ in epidemiology and pathogenic potential. EHV-4 is primarily associated with clinical respiratory disease, whereas EHV-1 is more frequently isolated from aborted fetuses, sickly foals, and neurologic cases. Both viruses frequently establish latent infections, but the relevance of latency to clinical disease is unclear. Diagnosis based on identification of the pathogen is generally superior to serologic methods. Vaccines containing each virus are available, and vaccination in concert with careful management limits the number of clinical cases. Immunity following vaccination or disease is not absolute, however, and improved disease prophylaxis awaits a better understanding of protective immune responses.

Abortion, Veterinary↗

Diagnosis of naturally occurring bovine viral diarrhea virus infections in ruminants using monoclonal antibody-based immunohistochemistry.

Formalin-fixed paraffin-embedded tissues from 50 spontaneous cases (39 bovine, nine ovine, two caprine) of bovine viral diarrhea virus (BVDV) infection diagnosed by virus isolation were retrospectively examined for BVDV antigen by immunohistochemistry using anti-BVDV gp-43 monoclonal antibody (Mab 15C5). The cases were separated into enteric disease syndrome, respiratory disease syndrome, and abortion/weak calf syndrome based upon clinical disease. The purposes of the study were to 1) compare routine virus isolation with immunohistochemistry in determining BVDV infection and 2) define tissue and cellular distribution of BVDV in various clinical manifestations of infection. In bovids, there was 100% concordance of virus isolation and immunohistochemistry using Mab 15C5 in cases of enteric disease (mucosal disease, acute and chronic diarrhea, neonatal diarrhea), respiratory disease, and abortion. When laboratory tests were restricted to gastrointestinal tissue and/or feces, virus isolation detected BVDV in only 65% of cattle, whereas immunohistochemistry detected BVDV antigen in 100% of cattle. Immunohistochemical detection of pestivirus was poor in cases of ovine abortion, ovine hairy shaker syndrome, and caprine abortion. The tissue distribution of BVDV antigen was widespread in individual cattle with all clinical forms of BVDV infection. Viral antigen accumulation was spatially correlated with tissue lesions (in the absence of other pathogens) only in the gastrointestinal tract, lymphoid tissue, lung, placenta, and eye. This study demonstrates the utility of immunohistochemistry using Mab 15C5 to diagnose BVDV infections in cattle with a broad spectrum of clinical disease.

Abortion, Veterinary↗