Spirochaetal Infections Research Articles

P029 Ocular syphilis: a mimicker for giant cell arteritis

Abstract Background/Aims Syphilis has seen a resurgence in the United Kingdom in recent years. It is a sexually transmitted disease caused by Treponema pallidum spirochaete infection, and typically presents as painless genital ulceration in its primary stage; left untreated it can progress rapidly to secondary and tertiary stages with multi-system involvement and wide-ranging symptoms, hence it being labelled ‘the great imitator’. We report a case of a patient presenting with classical features of giant cell arteritis (GCA), ultimately being diagnosed with neuro-ocular syphilis. Methods A 65-year-old man with a background of hypertension and migraines presented to our hospital with a 3-week history of temporal headache, scalp tenderness and jaw ache. He described lethargy, weakness and weight loss. On examination he had a prominent left temporal artery, with concurrent scalp tenderness; neurological and general medical examination were otherwise normal. Blood tests showed an erythrocyte sedimentation rate (ESR) of 66 and a C-reactive protein (CRP) of 115, leading to a strong clinical suspicion of GCA. He was commenced on 60mg of oral prednisolone with immediate improvement of his symptoms at this dose. Subsequent temporal artery ultrasound and temporal artery biopsy were negative for GCA. On tapering his steroids to 40mg he experienced partial relapse of his symptoms. Following Neurology review his steroid taper was adjusted to decrease more slowly. On 20mg of prednisolone the patient began experiencing stabbing retro-orbital pain and visual blurring, and was assessed by Ophthalmology with no local cause for his symptoms identified - he was therefore pulsed with intravenous methylprednisolone for a flare of GCA. Despite an initial response, the patient continued to experience intermittent symptoms on steroids; imaging with PET-CT did not show evidence of inflammation or malignancy and an MRI of his brain and orbits was normal. Results The patient eventually re-presented to Ophthalmology with floaters, pain and decreased vision and a spot diagnosis of posterior placoid chorioretinitis was made after retinal examination. Characteristic yellowish ovoid lesions confluent in the macular area were noted, as well as ellipsoid zone loss with nodular retinal pigment epithelium on optical coherence tomography (OCT) imaging. This condition is pathognomonic of neuro-ocular syphilis and serological testing confirmed the diagnosis, with a high rapid plasma reagin (RPR) titre of 1:512. He was treated with a course of intramuscular Ceftriaxone with a rapid resolution of his symptoms, and was successfully weaned off all steroid therapy. Conclusion Diagnosing GCA remains a clinical challenge for rheumatologists, especially in cases with typical symptoms and signs but negative confirmatory testing on imaging and histology. There are a wide range of conditions that resemble GCA, and neuro-ocular syphilis is one such diagnosis that has been reported in the literature as a mimic, as demonstrated by this important case. Disclosure S. Ali: None. S. Lekh: None. C. Tench: None.

Diagnosis of Human Leptospirosis: Comparison of Microscopic Agglutination Test with Recombinant LigA/B Antigen-Based In-House IgM Dot ELISA Dipstick Test and Latex Agglutination Test Using Bayesian Latent Class Model and MAT as Gold Standard.

Leptospirosis is a spirochaetal infection that possesses a broad host range affecting almost all mammals. In the present study, the microscopic agglutination test (MAT) was compared with recombinant LigA/B antigen-based point-of-care diagnostics such as the in-house IgM dot ELISA dipstick test (IgM- DEDT) and the latex agglutination test (LAT) for the serodiagnosis of human leptospirosis. The comparison of the MAT with these two point–of-care diagnostics was performed using the MAT as the gold standard test and using Bayesian latent class modelling (BLCM), which considers all diagnostic tests as imperfect. The N-terminal conserved region of the LigA/B protein spanning the first to fifth big tandem repeat domains (rLigA/BCon1-5) was employed as a serodiagnostic marker in both of the bedside assays. A total of 340 serum samples collected from humans involved in high risk occupations were screened using the MAT, IgM DEDT and LAT. During the early phase of leptospirosis, BLCM analysis showed that the IgM DEDT and LAT had similar sensitivities (99.6 (96.0–100)) and (99.5 (95.2–100)), respectively, while the single acute phase MAT had the lowest sensitivity (83.3 (72.8–91.3)). Both the IgM DEDT and the LAT may be superior to the single acute phase MAT in terms of sensitivity during the early phase of infection and may be suitable for the early diagnosis of leptospirosis. However, BLCM analysis revealed that the use of both acute and convalescent samples substantially increased the sensitivity of the final MAT (98.2% (93.0–99.8%)) as a test to diagnose human leptospirosis. Both the IgM DEDT and LAT can be employed as bedside spot tests in remote locations where the MAT is not easily accessible.

Dermatology clinical case

Lyme disease is a spirochaetal infection caused by Borrelia Burgdorferi sensu lato, which is transmitted by infected ticks of the genus Ixodes. It has a broad spectrum of clinical manifestations which, associated with its low incidence in Portugal, requires a high level of clinical suspicion for diagnosis. However, it is considered endemic in certain geographic areas, like Central Europe. The authors report the case of a child, living in Switzerland, who developed multiple erythema migrans lesions. Although parents did not recall a history of tick bite, Lyme disease diagnosis was established on clinical grounds, based on erythema and epidemiologic findings. When properly treated with oral antibiotic therapy, Lyme disease has an excellent prognosis. This case highlights the importance of epidemiologic history as a diagnostic clue.

Retrospective analysis of necrotizing typhlitis cases associated with Brachyspira spp. in British rheas

ABSTRACT This paper describes a retrospective analysis of necrotizing typhlitis in common rheas (Rhea americana) diagnosed in the United Kingdom by the Animal & Plant Health Agency (APHA). From January 2008 to January 2020, seven cases of spirochaetal typhlitis associated with Brachyspira spp. were identified using the Veterinary Investigation Diagnosis Analysis database. Gross examination was combined with selective anaerobic culture, polymerase chain reaction, and histopathology to diagnose typhlitis associated with spirochaetal infection. Whole-genome sequencing was subsequently utilized on archived isolates from six of the seven submissions, overcoming issues with traditional testing methods and yielded gains in the identification of Brachyspira to species level. Brachyspira hyodysenteriae, an organism traditionally associated with typhlitis in rheas, was isolated in three sequenced submissions. One of these also demonstrated co-infection with Brachyspira intermedia. Brachyspira suanatina, Brachyspira hampsonii, and Brachyspira alvinipulli were identified by sequencing as single infections in the remaining three animals. This report demonstrates the ability of Brachyspira species other than B. hyodysenteriae to colonize the caeca of rheas presenting with typhlitis. Additionally, the B. alvinipulli isolate harboured a tva(A) gene, indicating higher potential pleuromutilin resistance, which has not previously been described in this Brachyspira species. This study discusses the epidemiology of examined cases and examines the potential role other species may play in these outbreaks.

Questing Ixodes ricinus ticks (Acari, Ixodidae) as a vector of Borrelia burgdorferi sensu lato and Borrelia miyamotoi in an urban area of north-eastern Poland

Green areas located within large cities, as natural ecotypes, are a convenient habitat for ticks and their use as recreational areas is associated with the potential risk of acquiring tick-borne diseases. This study estimated the I. ricinus tick density, prevalence of infection with Borrelia species and the diversity of these bacteria in a green urban area (Olsztyn) of north-eastern Poland, an endemic region of tick-borne diseases. The ticks were collected during spring and autumn of 2015, at sites differing in the degree of human pressure and habitat. Borrelia species detection, typing and a molecular phylogenetic analysis were carried out based on the sequenced flaB gene. The overall mean abundance of I. ricinus was 2.0 ± 1.55 ticks per 100 m2. The density of I. ricinus did not vary significantly between sites. According to semi-qualitative tick abundance categories, the collection sites were classified as ‘very low’ and ‘low’ tick abundance category. The overall infection rate of I. ricinus with Borrelia spirochaetes was 27.4%. The infection rate of adult ticks (42.0%) was three times higher than with nymphs (14.3%). Based on the restriction patterns and sequencing, B. afzelii (93.1%; 27/29), B. valaisiana 3.5% (1/29) and B. miyamotoi (3.5%; 1/29), related to the relapsing fever (RF) spirochaetes, were detected. No co-infections were found. Borrelia miyamotoi, detected for the first time in ticks in the north-eastern urban areas of Poland, was identical to isolates described as European-type. The Borrelia spirochaete infection rate of I. ricinus ticks in an urban area indicated a high risk of LB. Physicians should also be aware of B. miyamotoi infections among patients with a history of tick-bites in north-eastern Poland.

Epidemiological Manifestations Ixodid Tick-Borne Borreliosies in Irkutsk and in other Parts of the Eurasian Area

Background . Ixodid tick-borne borrelioses (ITBB) is the most prevalent in Northern Hemisphere group of transmissible Spirochaetal infections, ecologically connected with Ixodid ticks. ITBB are etiologically associated with several agents, which determine epidemiological and clinical manifestations of these diseases. Research aim - the detection of ecological and epidemiological peculiarities of ITBB manifestations in the Baikal Region during the long-term period by comparison with that in the other parts of geographic range and the analysis of the manifestations dynamics. Material and methods. The database, developed by the authors, with information about ITBB cases in Irkutsk (1995-2017, n = 867) have been used in the work, and the similar studies in Russian and world literature have been reviewed. Statistical analysis was computed in Microsoft Excel Software. The map of infecting sites is made in ArcGis Soft (ESRI, USA). Results. The data have been analyzed on ecological and geographical (place and time of the infected tick bite), epidemiological (gender, age, localization of the tick bite, form of the disease), social and behavior (employment and circumstances of the infecting, including professional risk activities) signs. The interrelationship of some of them and their temporal evolution was studied. Similarities and differences of the ITBB manifestations in Baikal Region and other parts of the disease area have been revealed. The following peculiarities of ITBB in Baikal Region were found: 1) the average age of the patients is over 40; 2) a slightly higher number of males between the patients (57.3%); 3) increase (from several cases up to 40-47%) in the proportion of ITBB form without skin manifestations from the beginning to the end of the analyzed period; 4) the significant age difference between patients with and without skin manifestations (primarily persons over 50 and mainly the children respectively).

Presence of Borrelia spp. DNA in ticks, but absence of Borrelia spp. and of Leptospira spp. DNA in blood of fever patients in Madagascar

The occurrence of tick-borne relapsing fever and leptospirosis in humans in Madagascar remains unclear despite the presence of their potential vectors and reservoir hosts.We screened 255 Amblyomma variegatum ticks and 148 Rhipicephalus microplus ticks from Zebu cattle in Madagascar for Borrelia-specific DNA. Borrelia spp. DNA was detected in 21 Amblyomma variegatum ticks and 2 Rhipicephalus microplus ticks. One Borrelia found in one Rhipicephalus microplus showed close relationship to Borrelia theileri based on genetic distance and phylogenetic analyses on 16S rRNA and flaB sequences. The borreliae from Amblyomma variegatum could not be identified due to very low quantities of present DNA reflected by high cycle threshold values in real-time-PCR. It is uncertain whether these low numbers of Borrelia spp. are sufficient for transmission of infection from ticks to humans.In order to determine whether spirochaete infections are relevant in humans, blood samples of 1009 patients from the highlands of Madagascar with fever of unknown origin were screened for Borrelia spp. − and in addition for Leptospira spp. − by real-time PCR. No target DNA was detected, indicating a limited relevance of these pathogens for humans in the highlands of Madagascar.

The Fur homologue BosR requires Arg39 to activate rpoS transcription in Borrelia burgdorferi and thereby direct spirochaete infection in mice.

Borrelia burgdorferi is the causative agent of Lyme disease. In B. burgdorferi, RpoS controls the expression of virulence genes needed for mammalian infection. The Fur homologue BosR regulates the transcription of rpoS and therefore BosR determines, albeit indirectly, the infection status of the spirochaete. Transcription of rpoS in B. burgdorferi is complex: rpoS can be transcribed either from an RpoD-dependent promoter to yield a long transcript or from an RpoN-dependent promoter to yield a short transcript. This study shows that BosR repressed synthesis of the long transcript while at the same time activating synthesis of the short transcript. How BosR does this is unclear. To address this, spirochaetes were engineered to express either BosR or the naturally occurring variant BosRR39K. Mice became infected by the spirochaetes expressing BosR but not by the spirochaetes expressing BosRR39K. Furthermore, the spirochaetes expressing BosR activated rpoS transcription during growth in culture whereas the spirochaetes expressing BosRR39K did not. Thus, BosR's activation of rpoS transcription somehow involves Arg39. This arginine is highly conserved in other FUR proteins and therefore other FUR proteins may also require this arginine to function.

Activity of the tickIxodes ricinusmonitored in a suburban park in Brno, Czech Republic, in association with the evaluation of selected repellents

The ever-increasing number of Lyme borreliosis patients led us to consider more effective procedures for disease prevention. The aim of our study was to monitor the annual activity and infectivity of Ixodes ricinus ticks in the Pisárky region, City of Brno, CR, and to test the responses of the locally-captured ticks to selected repellents. The result of regular one-hour-per-week monitoring in 2011 was the collection of ticks that directly reflected the highest number of Lyme disease patients (4,835) detected throughout the period of recording in the Czech Republic. The ticks were examined for spirochaetes by dark field microscopy. The positive samples were identified by PCR analysis, confirming that 76% of these were infected with Borrelia burgdorferi sensu lato. Ticks were most abundant in May and June, with August having the highest risk for spirochaetal infection. Tick activity was statistically correlated with temperature. The moving-object-bioassay was used to study repellent efficiency on the Ixodes ricinus nymphs captured in the above-mentioned suburban park. Five selected commercial repellents based on DEET (N, N-diethyl-3-thylbenzamide) showed statistically different effects on the non-repellent control group.

The Jarisch–Herxheimer reaction in a patient with leptospirosis: a foreseeable problem in managing spirochaete infections

The Jarisch–Herxheimer reaction in a patient with leptospirosis: a foreseeable problem in managing spirochaete infections

Lyme disease.

Abstract Lyme disease is a focally endemic tick-borne spirochaetal infection that causes a well-defined constellation of symptoms. Diagnosis requires a combination of appropriate epidemiologic and clinical factors; laboratory confirmation with standardized serologic testing is highly accurate except in the setting of very early disease, such as in patients with erythema migrans, but is not helpful in judging treatment response. Treatment with simple, time-limited courses of penicillins, third-generation cephalosporins and tetracyclines is highly effective.

Identification of conserved antigens for early serodiagnosis of relapsing fever Borrelia

Borrelia hermsii is a blood-borne pathogen transmitted by the argasid tick Ornithodoros hermsi. Since spirochaete clearance in mice is associated with an IgM-mediated response, an immunoproteomic analysis was used to identify proteins reactive with IgM. We report that IgM from both mice and human patients infected with B. hermsii not only reacted with the previously identified variable membrane proteins but also identified candidate antigens including heat-shock proteins, an adhesin protein, ABC transporter proteins, flagellar proteins, housekeeping proteins, an immune evasion protein, and proteins with unknown function. Furthermore, IgM reactivity to recombinant glycerophosphodiester phosphodiesterase was detected during early spirochaete infection and prior to a detectable IgG response. Lastly, a conserved hypothetical protein was produced in Escherichia coli and tested with immune serum against B. hermsii and Borrelia recurrentis. These results identify a much larger set of immunoreactive proteins, and could help in the early serodiagnosis of this tick-borne infection.

Abrogation of ospAB constitutively activates the Rrp2‐RpoN‐RpoS pathway (sigmaN‐sigmaS cascade) in Borrelia burgdorferi

Molecular mechanisms underlying the reciprocal regulation of the two major surface lipoproteins and virulence factors of Borrelia burgdorferi, OspA and OspC, are not fully understood. Herein, we report that inactivation of the ospAB operon resulted in overproduction of OspC and many other lipoproteins via the constitutive activation of the Rrp2-RpoN-RpoS pathway. Complementing the ospAB mutant with a wild-type copy of ospA, but not an ospA variant that lacks the lipoprotein signal sequence, restored normal regulation of the Rrp2-RpoN-RpoS pathway; these results indicate that the phenotype was not caused by spurious mutations. Interestingly, while most of the ospAB mutant clones displayed a constitutive ospC expression phenotype, some ospAB mutant clones showed little or no ospC expression. Further analyses revealed that this OspC-negative phenotype was independent of abrogation of ospAB. While activation of the Rrp2-RpoN-RpoS pathway was recently shown to downregulate ospA, our findings suggest that reduction of OspA can also activate this pathway. We postulate that the activation of the Rrp2-RpoN-RpoS pathway and downregulation of OspA form a positive feedback loop that allows spirochaetes to produce and maintain a constant high level of OspC and other lipoproteins during tick feeding, a strategy that is critical for spirochaetal transmission and mammalian infection.

Plasma-cell cheilitis: successful treatment with intralesional injections of corticosteroids

Plasma-cell cheilitis is a rare inflammatory disorder of the lip characterized histologically by a band-like infiltrate of plasma cells in the upper dermis. It is considered an oral counterpart of plasma-cell balanitis. Clinically, it presents as a circumscribed, flat to slightly raised, eroded area of the lip. The cause of plasma-cell cheilitis is unknown, and the treatment is often disappointing. We describe a 55-year-old woman who had a long-lasting painful, swollen, and eroded area on her lips, which responded poorly to various topical treatments. Biopsy showed a band-like infiltrate composed mainly of mature plasma cells in the dermis. A diagnosis of plasma-cell cheilitis was made after excluding contact dermatitis, lichen planus, bacterial, fungal and spirochaete infections, and an extramedullary plasmacytoma. Dramatic improvements were observed after intralesional injections of corticosteroids. The lesion cleared up after two treatments, and there has been no recurrence in 1 year of follow-up.

Occurrence of multiple infections with different Borrelia burgdorferi genospecies in Danish Ixodes ricinus nymphs

The pathogen Borrelia burgdorferi causes Lyme Borreliosis in human and animals world-wide. In Europe the pathogen is transmitted to the host by the vector Ixodes ricinus. The nymph is the primary instar for transmission to humans. We here study the infection rate of five Borrelia genospecies: B. burgdorferi sensu stricto, B. afzelii, B. garinii, B. valaisiana, B. lusitaniae in nymphs, by IFA and PCR. 600 nymphs were collected in North Zealand of Denmark. Each nymph was first analysed by IFA. If positive for spirochaetal infection, the genospecies was determined by PCR. The infection rate of B. burgdorferi sensu lato was 15.5%, with the primary genospecies being B. afzelii (64.3%), B. garinii (57.1%), and B. lusitaniae (26.8%). It is the first time B. lusitaniae is documented in Denmark. Even though, the highest infection rate was discovered for B. afzelii and B. garinii, mixed infections are more common than single infections. Fifty-one percent (29/56) of these were infected with two genospecies, 7.1% (4/56) with three, and 5.3% (3/56) with four. We try to explain the high infection rate and the peculiar number of multiple infections, with a discussion of changes host abundance and occurrence of different transmission patterns.

The use of multilocus enzyme electrophoresis to characterise intestinal spirochaetes (Brachyspira spp.) colonising hens in commercial flocks

Multilocus enzyme electrophoresis (MLEE) was used to identify, examine genetic relationships and look at disease associations of a collection of 53 intestinal spirochaete isolates previously recovered from the faeces of adult hens on 14 farms in Qld, Australia. The MLEE results were compared with those previously obtained using species-specific PCR amplifications. The isolates were divided into five Brachyspira species groups by MLEE: Brachyspira murdochii (n=17), B. intermedia (n=15), B. pilosicoli (n=14), B. innocens (n=2) and "B. pulli" (n=1). Three new MLEE groups each containing single isolates also were identified. The results of the PCR assay for B. pilosicoli were concordant with the MLEE results, but the 23S rDNA-based PCR for B. intermedia had failed to detect 8 of the 15 isolates. The B. innocens/B. murdochii nox-based PCR had correctly identified all the isolates of B. murdochii, but did not identify either of the two B. innocens isolates. Using MLEE, isolates from two farms (14%) were identified as B. murdochii, whilst the pathogenic species B. intermedia and B. pilosicoli were present in hens from eight (57%) and five (36%) farms, respectively, and were identified together in four (29%) farms. All seven of the farms with production problems or wet litter were colonised with B. intermedia and/or B. pilosicoli. Six farms had multiple spirochaete isolates available for examination. Two broiler breeder farms both had five isolates of B. pilosicoli that shared the same MLEE electrophoretic type (ET), whilst one laying hen farm had three isolates of B. intermedia that all belonged to the same ET. Hence on each of these farms a predominant strain of a pathogenic species was present. On the other farms isolates of the same species were more diverse and belonged to different ETs. These results show that the epidemiology of intestinal spirochaetal infections in broiler breeder and laying hen flocks can vary considerably between farms, although the reasons for these differences were not established.

Ocorrência e identificação de espiroquetas intestinais em suínos em granjas de porte industrial de duas regiões criatórias do Estado do Rio Grande do Sul, em relação à medicação da ração

As infecções intestinais por espiroquetas em suínos, na fase que se segue ao alojamento nos prédios de recria, são predispostas por fatores como o estresse da movimentação, mistura entre animais imunes e excretores com leitões não imunes, deficiências nas condições ambientais e troca no tipo da ração usada. Para contrabalançar esses efeitos, é uma prática rotineira a inclusão de antimicrobianos à ração, em doses de promoção de crescimento ou de controle. O presente trabalho avaliou a ocorrência da infecção por Brachyspira spp. em rebanhos suínos do Estado do Rio Grande do Sul, tentando relacionar com o tipo de programa de uso de antimicrobianos adotado. Foram examinados 393 suabes retais colhidos de 38 granjas do RS (22 usando rações medicadas e 16 com ração sem medicação). A B. hyodysenteriae e B. pilosicoli foram detectadas respectivamente em 0% e 6,25% das granjas medicadas e de 31,8% e 45,5% das granjas não medicadas. Entre os suabes examinados, a B. hyodysenteriae e B. pilosicoli estavam presentes respectivamente em 0 e 0,6% dos materiais colhidos de granjas medicadas e de 3,9% e 7,3% em granjas não medicadas. O presente trabalho suporta a opinião de diversos autores que sugeriram a influência direta da inclusão de antimicrobianos à ração em doses de promoção de crescimento ou em dose de controle e a ocorrência de diarréias espiroquetais em leitões. Entretanto, pelas características multifatoriais desse tipo de patologia, seriam necessários estudos adicionais abrangendo um número maior de variáveis entre aquelas possivelmente envolvidas no desencadeamento das diarréias, antes que fosse obtida uma conclusão definitiva.

Association of Borrelia afzelii with rodents in Europe.

Borrelia burgdorferi sensu lato (s.l.) is maintained in nature by complex zoonotic transmission cycles, involving a large variety of vertebrates as hosts and hard ticks of the genus Ixodes as vectors. Recent studies suggest that the genospecies of B. burgdorferi s.l. and sometimes their subtypes are propagated by different spectra of hosts, mainly birds and rodents. In order to test the concept of host-association, we analysed the relationships between Borrelia genospecies, rodent hosts and I. ricinus ticks in an endemic focus of Lyme borreliosis in western Slovakia. Rodents and questing ticks were collected at a forested low land locality near Bratislava. Tick infestation levels on rodents were determined, and spirochaete infections in ticks and in ear punch biopsies were analysed by PCR followed by genotyping. Mice were more heavily infested with ticks than bank voles, and a higher proportion of mice was infected with spirochactes than voles. However, the infectivity of soles was much higher than that of mice. The vast majority of infections detected in the skin and in ticks feeding on the rodents represented B. afzelii. In contrast, more than half of all infections in questing ticks collected in the same region of Slovakia were identified as B. valaisiana and B. garinii. In conclusion, whilst the study reveals that mice and voles play different quantitative roles in the ecology of Lyme borreliosis, it demonstrates that B. afzelii is specifically maintained by European rodents, validating the concept of host-association of B. burgdorferi s.l.

Some relationships between spirochaete infections and digital dermatitis in four UK dairy herds

Digital dermatitis, presenting as a focal necrotic dermatitis on the skin of cows’ feet adjacent to the interdigital space, has been associated with dermal infection by spirochaetes. Lesions cause severe, transient lameness. An enzyme-linked immunoassay ( elisa) was used to measure IgG 2 antibody titres against three different spirochaetes: USA bovine Treponema isolates 1-9185 med and 2-1498, and a UK strain of Borrelia burgdorferi B31. Logistic models were used to describe lesion prevalence in terms of the antibody titres, herd and milking status, year, lactation number, and yield. The antibody titres and milking status ( P<0.001) dominated the logistic fits, with the other variables adding little. Generalised linear models were used to describe the antibody titres in terms of the presence or absence of lesions, herd, year, lactation number, and yield. The presence or absence of lesions had the most significant effect for all three antibodies ( P<0.001). Neither the herd effects nor the effects due to lactation number or yield showed consistent patterns.

Concurrent spirochaetal infections of the feet and colon of cattle in Japan.

To describe spirochaetal infections in the feet and colon of cattle affected with papillomatous digital dermatitis (PDD) and colitis respectively. Eighty-two slaughtered animals were macroscopically examined for the presence of PDD. Tissues of two cattle affected with PDD were examined by histology, immunohistochemistry, electron microscopy and bacteriology for spirochaetal infection. Two adult cattle (a 2-year-old beef bullock and 7-year-old Holstein dairy cow) were affected with PDD. Histologically, numerous argyrophilic and gram-negative filamentous or spiral spirochaetes were found deep in the PDD lesions. Epithelial and goblet cell hyperplasia and oedema of the lamina propria mucosa with macrophage and lymphocyte infiltration were observed in the caecum and colon in the cattle. Numerous spirochaetes were present in the crypts and some had invaded epithelial and goblet cells, and caused their degeneration. Immunohistochemically the organisms stained positively with polyclonal antisera against Treponema pallidum and Brachyspira (Serpulina) hyodysenteriae. Ultrastructurally, the intestinal spirochaetes were similar to the spirochaetes in PDD. They were 6 to 14 pm long, 0.2 to 0.3 pm wide and had 4 to 6 coils and 9 axial filaments per cell. Campylobacter species were isolated from the PDD and intestinal lesions, but spirochaetes were not. Concurrent infections with morphologically similar spirochaetal organisms may occur in the feet and colon of cattle in Japan.