Evaluating the impact of application of anaerobic bacterial fermentation enhancer on digital dermatitis.

The control of digital dermatitis (DD) among cattle is crucial; however, effective and environmentally-sound control measures have yet to be identified. From the monitoring data of DD which were recorded during regular hoof trimmings in a farm in Hokkaido, Japan, we detected a decrease in the DD prevalence in a herd where an anaerobic bacterial fermentation enhancer (ABFE) was distributed. The possible effect of ABFE was analyzed using a retrospective repeated cross-sectional design. The prevalence of DD decreased over time in the ABFE-distributed group. Furthermore, a selected regression model indicated the time-dependent enhancement of the decreasing trend. While potential coincidental factors may influence, this study provides a basis for further research on the preventive effect of ABFE against DD.

Bovine Digital Dermatitis: Treponema spp. on trimming equipment and chutes - effect of washing and disinfection.

BACKGROUND: Digital dermatitis (DD) is a contagious bovine foot disease causing reduced animal welfare and negative economic consequences for the farmer. Treponema spp. are the most important causative agents. Studies indicate that trimming equipment can transfer DD-associated treponemes between cows. The aim of this observational study in 22 DD-positive Norwegian dairy herds was to investigate the risk of transferring Treponema spp. with trimming equipment and chutes after claw trimming, and after washing and disinfection. Swabs from the trimming equipment and chutes were collected from nine different locations, at five different time points. Bacterial DNA was extracted from 647 swabs and analysed by qPCR for Treponema spp. In addition, 172 swabs taken immediately after trimming, were analysed by a multiplex qPCR targeting T. phagedenis, T. pedis and T. medium/vincentii. Biopsy sampling from DD lesions was performed on cows in the same herds during trimming. Altogether 109 biopsies were analysed by FISH for confirmation of the DD diagnosis and identification of Treponema phylotypes (PTs). RESULTS: High numbers of Treponema spp. were detected from all nine locations on the trimming equipment and chutes immediately after trimming, and T. phagedenis was detected on two or more locations in all but two herds, 1 and 19. There was a decline in the amount of Treponema spp. after washing and disinfection. The belly belt, the cuff, and the footrest on the chute had the highest proportion of positive samples after disinfection. The belly belt had the highest copy numbers of all nine locations (median = 7.9, max = 545.1). No Treponema spp. was detected on the hoof knives after disinfection. Treponema phagedenis, T. pedis, and Treponema phylotype 3 (T. refringens) were detected by FISH analysis of the biopsies. Treponema phagedenis was detected in biopsies from all herds except 1 and 19. CONCLUSION: This study shows that DD-associated Treponema spp. were present on the trimming equipment and chutes after trimming cows in DD-positive herds. Washing and disinfection reduced the load of Treponema spp. However, large differences in Treponema spp. between different locations were documented. High copy numbers on the grinder and the chute after disinfection, indicates that sufficient cleaning and disinfection of these locations is difficult, and that passive transfer of DD-associated treponemes (viable or not) is possible.

Ex vivo potential of a quinoline-derivative nail lacquer as a new alternative for dermatophytic onychomycosis treatment.

Introduction. Onychomycosis infections currently show a significant increase, affecting about 10 % of the world population. Trichophyton rubrum is the main agent responsible for about 80 % of the reported infections. The clinical cure for onychomycosis is extremely difficult and effective new antifungal therapy is needed.Hypothesis/Gap Statement. Ex vivo onychomycosis models using porcine hooves can be an excellent alternative for evaluating the efficacy of new anti-dermatophytic agents in a nail lacquer.Aim. Evaluation of the effectiveness of a nail lacquer containing a quinoline derivative on an ex vivo onychomycosis model using porcine hooves, as well as the proposal of a plausible antifungal mechanism of this derivative against dermatophytic strains.Methodology. The action mechanism of a quinoline derivative was evaluated through the sorbitol protection assay, exogenous ergosterol binding, and the determination of the dose-response curves by time-kill assay. Scanning electron microscopy evaluated the effect of the derivative in the fungal cells. The efficacy of a quinoline-derivative nail lacquer on an ex vivo onychomycosis model using porcine hooves was evaluated as well.Results. The quinoline derivative showed a time-dependent fungicidal effect, demonstrating reduction and damage in the morphology of dermatophytic hyphae. In addition, the ex vivo onychomycosis model was effective in the establishment of infection by T. rubrum.Conclusion. Treatment with the quinoline-derivative lacquer showed a significant inhibitory effect on T. rubrum strain in this infection model. Finally, the compound presents high potential for application in a formulation such as nail lacquer as a possible treatment for dermatophytic onychomycosis.

Novel ulcerative leg lesions in yearling lambs: Clinical features, microbiology and histopathology.

Here we report an outbreak of an atypical, ulcerative dermatitis in North Country mule lambs, located in South Gloucestershire, UK. The lesions, which appeared to be contagious, occured between the coronary band and the carpal joint as a focal, well demarcated, circular, ulcerative dermatitis. Histopathological examination of the lesion biopsies revealed areas of ulceration, epidermal hyperplasia, suppurative dermatitis and granulation tissue. Clumped keratohyalin granules and intracellular keratinocyte oedema (ballooning degeneration) were evident within lesion biopsies, consistent with an underlying viral aetiology. A PCR-based microbiological investigation failed to detect bovine digital dermatitis-associated treponeme phylogroups, Dichelobacter nodosus, Staphylococcus aureus, Dermatophilus congolensis or Chordopoxvirinae virus DNA. However, 3 of the 10 (30 %) and 6 of 10 (60 %) lesion samples were positive for Fusobacterium necrophorum and Streptococcus dysgalactiae DNA, respectively. Contralateral limb swabs were negative by all standard PCR assays. To better define the involvement of F. necrophorum in the aetiology of these lesions, a qPCR targeting the rpoB gene was employed and confirmed the presence of F. necrophorum DNA in both the control and lesions swab samples, although the mean F. necrophorum genome copy number detected in the lesion swab samples was ∼19-fold higher than detected in the contralateral control swab samples (245 versus 4752 genome copies/µl, respectively; P < 0.001). Although we have not been able to conclusively define an aetiological agent, the presence of both F. necrophorum and S. dysgalactiae in the majority of lesions assayed supports their role in the aetiopathogenesis of these lesions.

The prevalence of Dichelobacter nodosus in clinically footrot-free sheep flocks: a comparative field study on elimination strategies.

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 been subjected to different treatment strategies, to assess whether they were feasible for the eradication process, especially focussing on antimicrobial flock treatments. Clinical scoring and PCR-results were compared. Ten farms had used hoof bathing and hoof trimming without causing bleeding, ten had used individual treatments and flock vaccines to gain the free status and ten had become free through whole-flock systemic macrolide treatment. For every farm, three risk-based collected pool samples were analysed for the occurrence of virulent and benign D nodosus by PCR detection of aprV2/aprB2. RESULTS: Six flocks from any treatment group tested positive for aprB2 in all pools. Clinical signs were absent at the time of sampling, but some flocks had experienced non-progressive interdigital inflammation previously. Two flocks tested aprV2-positive in the high-risk pool. One of them underwent a progressive footrot outbreak shortly after sampling. Individual retesting indicated, that virulent D nodosus most likely was reintroduced by a recently purchased ram. In the second flock, a ram was tested positive and treated before clinical signs occurred. CONCLUSIONS: All treatment strategies eliminated the causative agent and were found to be suitable for implementation in the PCR-based eradication process. PCR-testing proved to be more sensitive than visual scoring, as it also detected clinically healthy carriers. It will be of benefit as a diagnostic tool in elimination and surveillance programs.

Acute phase response and clinical manifestation in outbreaks of interdigital phlegmon in dairy herds.

Several Finnish dairy herds have suffered from outbreaks of interdigital phlegmon (IP). In these new types of outbreaks, morbidity was high and clinical signs severe, resulting in substantial economic losses for affected farms. In our study, we visited 18 free stall dairy herds experiencing an outbreak of IP and 3 control herds without a similar outbreak. From a total of 203 sampled cows, 60 suffered from acute stage IP. We demonstrated that acute phase response of bovine IP was evident and therefore an appropriate analgesic should be administered in the treatment of affected animals. The response was most apparent in herds with high morbidity in IP and with a bacterial infection comprising Fusobacterium necrophorum and Dichelobacter nodosus, indicating that combination of these two bacterial species affect the severity of the disease.

[Acute outbreak of lameness due to inflammatory claw disease in a beef herd]. / Akuter Ausbruch von Lahmheit infolge entzündlicher Klauenhauterkrankungen in einem Mastbetrieb.

INTRODUCTION: Several young bulls in a beef farm showed large, foul-smelling skin lesions in the plantar region of the coronary band and in the interdigital space. Some of the animals also had a painful, warm swelling in the palmar fetlock area. All bulls were lame (score 4/5), the most severely affected animal had a lameness score of 5/5. Initial local treatment was unsuccessful, therefore the animals received parenteral antimicrobial treatment leading to improvement of clinical signs and weight bearing in most animals. However, several animals were slaughtered prematurely due to severe foot lesions. The diverse clinical picture did not allow for diagnosing one specific claw affection without further diagnostic investigations. Histopathological and bacteriological examinations confirmed the diagnosis of digital dermatitis (DD) in combination with an interdigital phlegmon, whereby five of the seven examined specimens were positive for one or more Treponema spp. Treponemes belong to the spirochetes, the ones commonly involved in DD in dairy cows include Treponema medium, Treponema phagedenis and Treponema pedis. The last two species were detected in the present cases. The clinical findings and results of diagnostic investigations indicate that a severe form of DD complicated by a secondary infection and interdigital phlegmon caused an outbreak of severe lameness in young bulls in a beef farm. Single or combined claw diseases can be associated with severe losses not only in dairy but also in beef herds.

INTRODUCTION: Plusieurs jeunes taureaux dans une exploitation d'engraissement ont présenté, en particulier aux membres postérieurs, des lésions étendues et malodorantes au niveau plantaire de la couronne, qui s'étendaient jusqu'à l'espace interdigital. Certains animaux présentaient une enflure chaude et très douloureuse dans le pli du boulet. Les animaux étaient fortement boiteux (4/5), le taureau le plus atteint présentait une boiterie très sévère (5/5). Un traitement initial local a été mis en place, cependant, en l'absence de succès thérapeutique, les animaux ont été ensuite traités par voie parentérale avec un antibiotique, ce qui permis de réduire la sévérité du tableau clinique et d'améliorer la charge des membres atteints. En raison de la gravité des lésions, plusieurs animaux ont toutefois dû être abattus prématurément. Au vu de la diversité du tableau clinique, la maladie n'a pas pu être attribuée à une maladie des onglons particulière sans clarification supplémentaire du diagnostic. Un diagnostic de dermatite digitale en combinaison avec un phlegmon interdigital a été confirmé par l'analyse histopathologique ainsi que l'examen bactériologique: cinq des sept écouvillons examinés étaient positifs pour un ou plusieurs Treponema spp. Dans la famille des spirochètes, Treponema medium, Treponema phagedenis et Treponema pedis sont les tréponèmes le plus souvent impliqués dans la dermatite digitale chez les vaches laitières. Les deux germes mentionnés en dernier ont été mis en évidence dans les échantillons prélevés sur les taureaux d'engraissement décrits ici. L'image clinique et les résultats d'analyses des échantillons examinés suggèrent qu'une forme sévère de dermatite digitale compliquée par une infection secondaire et le développement d'un phlegmon interdigital s'est développée lors de l'épidémie de forte boiterie observée dans une exploitation d'engraissement. Les maladies des onglons, individuellement ou en combinaison, peuvent donc occasionner des pertes importantes dans les exploitations d'engraissement.

Sites of persistence of Fusobacterium necrophorum and Dichelobacter nodosus: a paradigm shift in understanding the epidemiology of footrot in sheep.

Sites of persistence of bacterial pathogens contribute to disease dynamics of bacterial diseases. Footrot is a globally important bacterial disease that reduces health and productivity of sheep. It is caused by Dichelobacter nodosus, a pathogen apparently highly specialised for feet, while Fusobacterium necrophorum, a secondary pathogen in footrot is reportedly ubiquitous on pasture. Two prospective longitudinal studies were conducted to investigate the persistence of D. nodosus and F. necrophorum in sheep feet, mouths and faeces, and in soil. Molecular tools were used to detect species, strains and communities. In contrast to the existing paradigm, F. necrophorum persisted on footrot diseased feet, and in mouths and faeces; different strains were detected in feet and mouths. D. nodosus persisted in soil and on diseased, but not healthy, feet; similar strains were detected on both healthy and diseased feet of diseased sheep. We conclude that D. nodosus and F. necrophorum depend on sheep for persistence but use different strategies to persist and spread between sheep within and between flocks. Elimination of F. necrophorum would be challenging due to faecal shedding. In contrast D. nodosus could be eliminated if all footrot-affected sheep were removed and fade out of D. nodosus occurred in the environment before re-infection of a foot.

Ciclopirox and Efinaconazole Transungual Permeation, Antifungal Activity, and Proficiency To Induce Resistance in Trichophyton rubrum.

Onychomycosis is a nail fungal infection, mostly caused by dermatophytes. The treatment efficacy is impaired by difficulties of reaching effective drug levels at the site of infection; frequent relapses occur after cessation of antifungal therapy. The aim of the study was to compare two commercial products containing ciclopirox or efinaconazole for antimycotic activity and antifungal drug resistance. A study of permeation and penetration through bovine hoof membranes, as a nail model, was performed to evaluate the antimycotic activity of permeates against clinical isolates of selected fungi, and the frequency of spontaneous in vitroTrichophyton rubrum-resistant strains was assessed by broth microdilution assays. The results suggest that ciclopirox creates a depot in the nail, leading to a gradual release of the drug over time with action on both the nail plate and bed. Conversely, efinaconazole, mildly interacting with nail keratin, mainly exerts its antifungal activity in the nail bed. However, in the case of T. rubrum, the antifungal activities of the drugs in the nail plate seem comparable. Finally, efinaconazole showed a potential for induction of resistance in T. rubrum, which may limit its efficacy over time. Ciclopirox did not show any potential to induce resistance in T. rubrum and appears endowed with a more complete activity than efinaconazole in the management of onychomycosis as the nail keratin is a substrate for the growth of fungal cells, and the availability of drug in large concentration just in the nail bed may not be sufficient to guarantee the complete eradication of pathogens.

[Footbath as treatment of footrot in sheep. Current -situation on Swiss sheep farms]. / Klauenbad zur Bekämpfung der ­Moderhinke bei Schafen. Eine Bestandes­aufnahme bei Schweizer Schafhaltern.

INTRODUCTION: Footrot in sheep should be eradicated in Switzerland in the future. Based on scientific findings, this can be achieved with disinfectant footbaths. It is unknown how many sheep farmers are already using this means and how it is used. The current study evaluated the farm operation, the design of the footbath, the use of disinfectants and footbath with a written survey of a representative sample of all sheep farmers. The sample population was selected randomly, however stratified by language region and herdsize to control for differences between these groups. 45.3% (n=1134) of the distributed questionnaires were received for evaluation. On average 32.8% of the respondents used a footbath. Even on large farms (> 50 animals), which were more frequently affected by footrot, a footbath was available only in 52.6% of the farms in the French-speaking part and 67.7% in the German/Italian speaking part of Switzerland. The footbaths were correctly applied in most respects (e.g., pre-claw cleaning, liquid level and concentration of disinfectants, time in the footbath, post-bath drying phase) in the current study. Most commonly mobile plastic baths were in use. The disinfectants used were mainly formalin, copper and zinc sulfate. The incorrect disposal of the heavy-metal containing copper and zinc sulfate solutions was identified as an important problem: In 59% of the sheep farms the remaining footbath solutions were disposed in the slurry pit or manure storage. In summary the current study recommends (i) to motivate sheep farmers to use a footbath for the treatment and prevention of footrot, and (ii) to replace the currently used disinfectants with substances that are non-toxic to humans, animals and the environment.

INTRODUCTION: Le piétin du mouton doit être, à l'avenir, combattu sur l'ensemble du territoire suisse. Sur la base des connaissances scientifiques, cela peut être fait avec un bain désinfectant pour les onglons. On ignore combien d'éleveurs utilisent déjà cette mesure et comment elle est utilisée. On a cherché, au moyen d'un sondage d'un échantillon représentatif d'éleveurs de moutons, à obtenir la réponse à quatre groupes de questions sur l'exploitation, la construction du pédiluve, l'utilisation de désinfectants et l'usage du bain des onglons. La stratification concernant la région linguistique d'une part et la taille du troupeau d'autre part, permettait de donner la meilleure image possible dans l'échantillon. Avec l'évaluation de 1134 des questionnaires évaluables (45,3% de ceux initialement envoyés) ont a constaté qu'en moyenne 32,8% seulement des exploitants utilisaient un bain des onglons. Même avec les grands troupeaux avec > 50 animaux, qui sont donc plus fréquemment touchés par le piétain, seuls 52,6% des exploitants francophones respectivement 67,7% des germanophones ou des italophones disposent d'un bain. D'autre part, les utilisateurs de bain des onglons appliquent dans la plupart des cas correctement les aspects principaux (par ex.: prélavage des onglons, niveau de liquide et concentration des désinfectants, temps passé dans le bain, phase de séchage après le bain). Les installations les plus communément utilisées étaient les bains mobiles en plastique. La formaline, le sulfate de cuivre et de zinc étaient principalement utilisés comme désinfectants. On constatait un grand manque quant à l'élimination des désinfectants, en particulier des solutions contenant des métaux lourds comme le cuivre ou le zinc. Ainsi, 59,4% des éleveurs ont déclaré jeter les liquides dans la fosse à lisier ou sur le tas de fumier. Les constatations principales sont donc: (i) que les éleveurs de moutons devraient être motivés à utiliser un bain des onglons pour le traitement et la prévention du piétain, et (ii) que le remplacement des désinfectants actuellement utilisés par des substances non toxiques pour l'homme, l'animal et l'environnement est absolument nécessaire.

DirtyGenes: testing for significant changes in gene or bacterial population compositions from a small number of samples.

High throughput genomics technologies are applied widely to microbiomes in humans, animals, soil and water, to detect changes in bacterial communities or the genes they carry, between different environments or treatments. We describe a method to test the statistical significance of differences in bacterial population or gene composition, applicable to metagenomic or quantitative polymerase chain reaction data. Our method goes beyond previous published work in being universally most powerful, thus better able to detect statistically significant differences, and through being more reliable for smaller sample sizes. It can also be used for experimental design, to estimate how many samples to use in future experiments, again with the advantage of being universally most powerful. We present three example analyses in the area of antimicrobial resistance. The first is to published data on bacterial communities and antimicrobial resistance genes (ARGs) in the environment; we show that there are significant changes in both ARG and community composition. The second is to new data on seasonality in bacterial communities and ARGs in hooves from four sheep. While the observed differences are not significant, we show that a minimum group size of eight sheep would provide sufficient power to observe significance of similar changes in further experiments. The third is to published data on bacterial communities surrounding rice crops. This is a much larger data set and is used to verify the new method. Our method has broad uses for statistical testing and experimental design in research on changing microbiomes, including studies on antimicrobial resistance.

Bacterial species associated with interdigital phlegmon outbreaks in Finnish dairy herds.

BACKGROUND: Severe outbreaks of bovine interdigital phlegmon (IP) have occurred recently in several free stall dairy herds in Finland. We studied the aetiology of IP in such herds, and the association of bacterial species with the various stages of IP and herds of various morbidity of IP. Nineteen free stall dairy herds with IP outbreaks and three control herds were visited and bacteriological samples collected from cows suffering from IP (n = 106), other hoof diseases (n = 58), and control cows (n = 64). The herds were divided into high morbidity (morbidity ≥50%) and moderate morbidity groups (9-33%) based on morbidity during the first two months of the outbreak. RESULTS: F. necrophorum subspecies necrophorum was clearly associated with IP in general, and T. pyogenes was associated with the healing stage of IP. Six other major hoof pathogens were detected; Dichelobacter nodosus, Porphyromonas levii, Prevotella melaninogenica, Treponema spp. and Trueperella pyogenes. Most of the samples of acute IP (66.7%) harboured both F. necrophorum and D. nodosus. We found differences between moderate morbidity and high morbidity herds. D. nodosus was more common in IP lesion in high than in moderate morbidity herds. CONCLUSIONS: Our result confirms that F. necrophorum subspecies necrophorum is the main pathogen in IP, but also T. pyogenes is associated with the healing stage of IP. Our results suggest that D. nodosus may play a role in the severity of the outbreak of IP, but further research is needed to establish other bacteriological factors behind these severe outbreaks.

Treponeme-Associated Hoof Disease of Free-Ranging Elk ( Cervus elaphus) in Southwestern Washington State, USA.

A novel foot disease in free-ranging elk ( Cervus elaphus) in southwestern Washington State emerged in 2008 and spread throughout the region. Initial studies showed adult elk had chronic hoof overgrowth, sole ulcers, and sloughed hoof capsules, but no cause was determined. To identify possible causes and characterize the earliest lesions, 9-, 7-, and 3-month-old elk were collected. Nine-month-old elk had sole ulcers (3/9 elk) and sloughed/overgrown hoof capsules (4/9 elk) similar to adults. Histologically, lesions consisted of coronary, heel bulb, and interdigital ulcers with suppurative inflammation, epithelial hyperplasia, deeply invasive spirochetes, and underrunning of the hoof capsule and heel-sole junction. Spirochetes were identified as Treponema via immunohistochemistry and polymerase chain reaction (PCR). Seven-month-old elk had similar underrunning foot ulcers (6/8 elk) with Treponema identified in all lesions but no chronic overgrowth or sloughed hoof capsules. Three-month-old calves had superficial coronary erosions with no inflammation or identifiable spirochetes (3/5 elk) but were culture/PCR positive for Treponema, suggesting possible early lesions. Lesions from 9- and 7-month-old elk included aerobic and anaerobic bacteria, many of which are associated with infectious foot disease in livestock. Antibody enzyme-linked immunosorbent assay of 7- and 3-month-old elk from the enzootic region showed a trend toward increased Treponema antibody titers compared to normal control elk from outside the region, further supporting the significance of Treponema in the pathogenesis of foot disease. Treponeme-associated hoof disease (TAHD) in elk, a debilitating and progressive condition, shares similarities to bovine digital dermatitis and contagious ovine digital dermatitis.

Severe Streptococcal Infection Following Cat Scratch.

INTRODUCTION: Cats can transmit bacterial infections to humans through biting and scratching. Streptococcal infections in wounds caused by cat bites or scratches rarely have been reported in the literature. CASE REPORT: The case of severe streptococcal skin infection after a 2-day-old cat scratch of the right arm, elbow, and forearm in a 68-year-old woman is presented herein. Group A ß-hemolytic streptococci (GABHS) was isolated from the wound of the patient as well as the oral cavity and claws of the cat; likewise, Escherichia coli also was isolated from the oral cavity and claws of the cat. She was successfully treated with intravenous tigecycline for 2 weeks at a starting dosage of 100 mg daily. Tetanus prophylaxis was performed. Complete remission was observed 3 weeks after beginning treatment. Follow-up visit at 32 months was negative for clinical manifestations. CONCLUSIONS: For the first time documented in the literature, GABHS were isolated from the wound of the patient and from the cat's oral cavity and claws.

Potential transmission routes of Dichelobacter nodosus.

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 determined the prevalence of D. nodosus in sheep presented at shows and markets where commingling of animals occurs. Furthermore, possible transmission vectors during foot trimming were investigated and trimming knife decontamination protocols evaluated. Sheep at six markets and four shows were sampled and tested for the presence of D. nodosus by real-time PCR. Different vectors, such as trimming knives were tested by real-time PCR and for viable D. nodosus by culture. The prevalence of virulent D. nodosus in sheep presented at shows and markets ranged from 1.7% to 100%. Regions with an ongoing control program showed significantly lower prevalence. After trimming, positive real-time PCR and culture results were obtained from the knives, the hands of the claw trimmers as well as removed claw horn material whereas boots were only positive by real-time PCR. In conclusion, markets and shows pose a risk for transmission of D. nodosus. The risk of transmission is particularly high during claw trimming and recommended measures to limit this risk include wiping the knife with a disinfection towel, wearing and changing gloves after every sheep, as well as proper disposal of trimmed and infectious horn.

Detection and Serogrouping of Dichelobacter nodosus Infection by Use of Direct PCR from Lesion Swabs To Support Outbreak-Specific Vaccination for Virulent Footrot in Sheep.

Virulent footrot is an economically significant disease in most sheep-rearing countries. The disease can be controlled with vaccine targeting the fimbriae of virulent strains of the essential causative agent, Dichelobacter nodosus However, the bacterium is immunologically heterogeneous, and 10 distinct fimbrial serogroups have been identified. Ideally, in each outbreak the infecting strains would be cultured and serogrouped so that the appropriate serogroup-specific mono- or bivalent vaccine could be administered, because multivalent vaccines lack efficacy due to antigenic competition. If clinical disease expression is suspected to be incomplete, culture-based virulence tests are required to confirm the diagnosis, because control of benign footrot is economically unjustifiable. Both diagnosis and vaccination are conducted at the flock level. The aims of this study were to develop a PCR-based procedure for detecting and serogrouping D. nodosus directly from foot swabs and to determine whether this could be done accurately from the same cultured swab. A total of 269 swabs from the active margins of foot lesions of 261 sheep in 12 Merino sheep flocks in southeastern Australia were evaluated. DNA extracts taken from putative pure cultures of D. nodosus and directly from the swabs were evaluated in PCR assays for the 16S rRNA and fimA genes of D. nodosus Pure cultures were tested also by the slide agglutination test. Direct PCR using extracts from swabs was more sensitive than culture for detecting and serogrouping D. nodosus strains. Using the most sensitive sample collection method of the use of swabs in lysis buffer, D. nodosus was more likely to be detected by PCR in active than in inactive lesions, and in lesions with low levels of fecal contamination, but lesion score was not a significant factor. PCR conducted on extracts from swabs in modified Stuart's transport medium that had already been used to inoculate culture plates had lower sensitivity. Therefore, if culture is required to enable virulence tests to be conducted, it is recommended that duplicate swabs be collected from each foot lesion, one in transport medium for culture and the other in lysis buffer for PCR.

Domestic feline contribution in the transmission of Sporothrix in Rio de Janeiro State, Brazil: a comparison between infected and non-infected populations.

BACKGROUND: Sporotrichosis is a neglected zoonosis caused by pathogenic fungi belonging to the Sporothrix schenckii complex. In Rio de Janeiro state, this disease reached an epidemic status with over 4700 domestic felines and around 4000 humans affected since the mid-90s. The present study evaluated clinical and epidemiological aspects and also the frequency of colonization and infection by these fungi in healthy cats and among those with suspicious cutaneous lesions, inhabiting four Rio de Janeiro state distinct areas. RESULTS: Three hundred and seventy-one cats were included in two groups: 175 healthy cats [CRG] and 196 cats showing lesions suggesting sporotrichosis [SSG]. Mycological diagnosis allowed SSG animals to be divided in positive [104 cats; +SG] and negative [92 cats; -SG] groups. Nails, oral mucosa and lesions swabs were submitted to culture and potential colonies were subculture for micromorphologycal analysis, dimorphism and molecular tests. In the CRG, only one cat was colonized in the oral cavity [0.57%]; in the -SG group, four animals showed colonization of the nail and/or oral cavity [4.3%]; while the highest frequency of colonization [39.4%] was observed in the +SG. All molecularly typed isolates were identified as S. brasiliensis. CONCLUSION: The results obtained here indicate that healthy cats have a minor role in sporotrichosis transmission within the state of Rio de Janeiro. Conversely, a higher participation of diseased feline in sporotrichosis transmission was evidenced, especially by the colonization of their oral cavity. Sporothrix brasiliensis equally affects and colonizes animals from distinct Rio de Janeiro state areas. Thus, we hypothesize that sporotrichosis is a uniform endemic throughout the state, whose transmission depends mainly on the contact with cats with sporotrichosis. Since Rio de Janeiro displays a world unique epidemic model of the disease, not fully understood, data on the infected and non-infected animals can be of major importance for future strategies of sporotrichosis prevention and control. Finally, considering the importance of the current concept of "one health", the experience here observed can be helpful for distinct epizootias and/or zoonosis.

Evaluation of the Ability of a Novel Miconazole Formulation To Penetrate Nail by Using Three In Vitro Nail Models.

In an effort to increase the efficacy of topical medications for treating onychomycosis, several new nail penetration enhancers were recently developed. In this study, the ability of 10% (wt/wt) miconazole nitrate combined with a penetration enhancer formulation to permeate the nail is demonstrated by the use of a selection of in vitro nail penetration assays. These assays included the bovine hoof, TurChub zone of inhibition, and infected-nail models.

Prospective case-control study of toe tip necrosis syndrome (TTNS) in western Canadian feedlot cattle.

A case-control study was conducted to investigate potential risk factors for toe tip necrosis syndrome (TTNS) in western Canadian feedlot cattle. Feedlot veterinarians provided hooves from 222 animals that died of either TTNS ("cases") or from all other causes ("controls"). The claws were sectioned by researchers to confirm the diagnoses; there was very good agreement between the practitioners' field diagnosis and that of the researchers (Cohen's kappa = 0.81; P < 0.001). The sole thickness of the apical white line region was thinner (P < 0.001) in the cases (3.74 mm) than the controls (4.72 mm). Claws from cases were 5.0 [95% confidence interval (CI): 1.5 to 8.6; P < 0.001] and 7.3 times (95% CI: 1.5 to 69.3; P < 0.01) more likely than those of controls to yield a heavy growth of Escherichia coli and Trueperella pyogenes, respectively. Cases were 4.4 times (95% CI: 4.4 to 22.9; P < 0.001) more likely to be acutely/transiently infected with bovine viral diarrhea virus than were controls. The findings support the hypothesis that TTNS is initiated by excessive wear along the white line, leading to separation and bacterial colonization of the 3rd phalangeal bone (P3) and associated soft tissues.

Étude prospective de cas-témoins du syndrome de la nécrose du bout des orteils dans un parc d'engraissement de l'Ouest canadien. Une étude de cas-témoins a été réalisée pour investiguer les facteurs de risques potentiels pour le syndrome de la nécrose du bout des orteils (SNBO) chez le bétail des parcs d'engraissement de l'Ouest canadien. Les vétérinaires des parcs d'engraissement ont fourni des sabots provenant de 222 animaux qui sont morts soit du SNBO («cas¼) ou d'autres causes («témoins¼). Les ongles ont été sectionnés par les chercheurs pour confirmer les diagnostics; il y avait une très bonne concordance entre le diagnostic sur le terrain des praticiens et celui des chercheurs (Kappa de Cohen = 0,81; P < 0,001). L'épaisseur de la sole dans la région de la ligne blanche atypique était plus mince (P < 0,001) dans les cas (3,74 mm) que dans les témoins (4,72 mm). Il était 5,0 fois (IC de 95 % de 1,5 à 8,6; P < 0,001) et 7,3 fois (IC de 95 % de 1,5 à 69,3; P < 0,01) plus probable que les ongles des cas donnent une croissance importante d'Escherichia coli et de Trueperella pyogenes, respectivement. Il était 4,4 fois (IC de 95 % de 4,4 à 22,9; P < 0,001) plus probable que les cas soient infectés de manière aiguë ou transitoire par le virus de la diarrhée virale des bovins comparativement aux témoins. Les résultats appuient l'hypothèse que le SNBO est amorcé par une usure excessive le long de la ligne blanche, ce qui entraîne une séparation et la colonisation bactérienne de l'os de la troisième phalange (P3) et des tissus mous connexes.(Traduit par Isabelle Vallières).

Evaluation of cytology collection techniques and prevalence of Malassezia yeast and bacteria in claw folds of normal and allergic dogs.

BACKGROUND: Canine bacterial and Malassezia paronychia are common secondary complications of atopic dermatitis and adverse food reactions. HYPOTHESIS/OBJECTIVES: The aim of this study was to compare three different sampling methods for claw fold cytology and to evaluate the numbers of bacteria, Malassezia yeast and inflammatory cells. ANIMALS: Sixty client-owned dogs were classified into three groups: (A) normal dogs; (B) allergic dogs with no clinical evidence of claw disease (brown staining, erythema, swelling, crusts or exudates); and (C) allergic dogs with clinical paronychia. METHODS: A prospective, blinded, split-plot study design was used. Claw folds from each dog were sampled using either a toothpick, tape preparation or direct impression smear. Slides were evaluated by two investigators for inflammatory cells, nuclear streaming, debris, corneocytes, yeast, intracellular (IC) cocci, extracellular (EC) cocci, IC rods and EC rods. For each parameter, data were compared between groups and between methods. Inter-reader agreements were calculated. RESULTS: Group C had significantly higher values of EC cocci and corneocytes than Groups A or B. Although Malassezia organisms were more prevalent in allergic dogs than normal dogs, the counts were not significantly different. There were significantly higher numbers of Malassezia organisms (P = 0.0016) and EC cocci (P = 0.0106) retrieved from samples collected with a toothpick compared to other methods. Tape preparations were associated with significantly more debris and corneocytes (both P < 0.0001) and impression smears with significantly more nuclear streaming (P = 0.0468). CONCLUSIONS AND CLINICAL IMPORTANCE: Sample collection using a toothpick optimizes the value of cytological results when sampling allergic dogs with clinical paronychia.