Mycoplasma mycoides subspecies capri, an uncommon mastitis and respiratory pathogen isolated in a German flock of goats

Mycoplasma mycoides ssp. capri (Mmc) is one of the etiological microorganisms of contagious agalactia, which is among the diseases causing the highest economical losses in small ruminants. We report a disease outbreak in a German flock that led to significant suffering of goats characterized by mastitis, arthritis, pleuropneumonia and sudden deaths. Mmc was persistently isolated from many animals both from milk, and from a number of different swab and tissue samples. A number of closely related Mycoplasma spp. have to be taken into consideration to rule out important animal epizootics listed by European Animal Health Law and the World Organisation for Animal Health (WOAH). Some goats developed cross-reacting antibodies against Mycoplasma mycoides ssp. mycoides. Although Mmc is believed to be an uncommon microorganism in Germany, this study highlights that veterinarians should consider this pathogen in their work during herd health monitoring in Central Europe. Although eradication was not fully achieved, autogenous vaccination significantly seemed to improve animal health and welfare.

Clinical infection in house rats (Rattus rattus) caused by Streptobacillus notomytis

Rat bite fever is an under-reported, under-diagnosed emerging zoonosis with worldwide distribution. Besides Spirillum minus, Streptobacillus moniliformis is the major causative microorganism although it usually colonises rats without any clinical signs. A group of house rats (Rattus rattus) kept in a zoo exhibition for educational purposes suffered from neurological signs including disorientation, torticollis, stall walking, ataxia and death. Gross pathological and histo-pathological examinations of the investigated rats revealed high-grade otitis interna et media, from which Streptobacillus notomytis was isolated in pure culture or as the predominant microorganism. This case series underlines a previously expressed hypothesis that R. rattus might be naturally colonised with S. notomytis, whereas the traditional rat bite fever organism, S. moniliformis, might be restricted to the Norway rat (Rattus norvegicus). However, the general paucity of Streptobacillus isolates, especially from their respective animal hosts, precludes definitive proof of these host tropisms. This is the first report of S. notomytis detection outside Asia and Australia and the first evidence for its role as a facultative pathogen in house rats.

Fatal infection in three Grey Slender Lorises (Loris lydekkerianus nordicus) caused by clonally related Trueperella pyogenes

Background

Trueperella pyogenes is a worldwide known bacterium causing mastitis, abortion and various other pyogenic infections in domestic animals like ruminants and pigs. In this study we represent the first case report of three unusual fatal infections of Grey Slender Lorises caused by Trueperella pyogenes. Meanwhile, this study represents the first in-depth description of the multilocus sequence analysis (MLSA) on T. pyogenes species.

Case presentation

Three Trueperella pyogenes were isolated from three different Grey Slender Lorises, which died within a period of two years at Frankfurt Zoo (Frankfurt am Main - Germany). The three Grey Slender Loris cases were suffering from severe sepsis and died from its complication. During the bacteriological investigation of the three cases, the T. pyogenes were isolated from different organisms in each case. The epidemiological relationship between the three isolates could be shown by four genomic DNA fingerprint methods (ERIC-PCR, BOX-PCR, (GTG)₅-PCR, and RAPD-PCR) and by multilocus sequence analysis (MLSA) investigating four different housekeeping genes (fusA-tuf-metG-gyrA).

Conclusion

In this study, we clearly showed by means of using three different rep-PCRs, by RAPD-PCR and by MLSA that the genomic fingerprinting of the investigated three T. pyogenes have the same clonal origin and are genetically identical. These results suggest that the same isolate contaminated the animal’s facility and subsequently caused cross infection between the three different Grey Slender Lorises. To the best of our knowledge, this is the first epidemiological approach concentrating on T. pyogenes using MLSA.

[Pathologic-anatomical changes in newborn goats caused by an intrauterine Schmallenberg virus infection]

A complex of various malformations in newborns was observed to an increased extent in sheep farms in the 2011/2012 lambing season. An intrauterine Schmallenberg virus (SBV) infection was identified as the cause of these malformations. To date, a detailed pathological description of the deformity complex has only been given for bovine and ovine newborns.The aim of this study was therefore to provide a description of pathologic-anatomical congenital malformations in goat kids caused by intrauterine SBV infection. To this end, pathologic-anatomical and molecular biological investigations by PCR were carried out on 37 goat kids and 457 lambs from 238 sheep and goat farms in order to carry out an interspecies comparison. Of the 37 goat kids dissected, it was possible to identify a SBV infection in twelve animals (32.4%) by RT-PCR. In nine animals (24.3%) displaying pathological-anatomical malformations SBV could not be detected by PCR. The following malformations were observed: athrogryposis, deformation of spinal column, torticollis, asymmetry of the skull, brachygnathia inferior, cerebellar hypoplasia, cerebellar aplasia and internal hydrocephalus. Arthogryposis was the most common malformation, both in animals with positive PCR results and those with negative PCR results. This study documents congenital malformations caused by an intrauterine SBV infection for the first time on a large number of newborn goats.

Trueperella pyogenes as cause of a facial abscess in a grey slender loris (Loris lydekkerianus nordicus)--a case report

In the present study a Trueperella (T.) pyogenes strain isolated from an abscess on the left side of the face of a six year old grey slender loris (Loris lydekkerianus nordicus) could successfully be identified phenotypically, by MALDI-TOF MS analysis and genotypically using T. pyogenes superoxide dismutase A encoding gene sodA and T. pyogenes 16S-23S rDNA intergenic spacer region specific oligonucleotide primers. The T. pyogenes strain could additionally be characterized by PCR-mediated amplification of several known and putative virulence factor encoding genes which revealed the presence of the genes plo encoding pyolysin, nanH encoding neuraminidase NanH and the genes fimA, fimC, fimE encoding the fimbrial subunits FimA, FimC and FimE but not the genes cbpA and nanP encoding collagen-binding protein CbpA and neuraminidase NanP, respectively. The present data give the first information about properties of T. pyogenes isolated from a monkey.

Evaluation of Lawsonia intracellularis infection in a group of pigs in a subclinically affected herd from weaning to slaughter

The purpose of this study was to follow the course of a subclinical Lawsonia (L.) intracellularis infection in a group of 60 pigs on a commercial farm from weaning to slaughter. From 6 to 16 and at 26 weeks of age, rectal faecal samples and blood samples were collected weekly from every pig for examination by PCR and blocking ELISA, respectively. At corresponding times starting at 8 weeks of age, pigs were randomly selected for necropsy (n=51). Intestinal tissues were examined histopathologically and by immunohistochemistry (IHC) for L. intracellularis antigen. Infection with L. intracellularis showed a mainly subclinical course. Shedding of L. intracellularis was detected by PCR in three pigs as early as 6 weeks of age and persisted up until 14 weeks of age. In most pigs shedding of L. intracellularis was seen only for 1-2 weeks followed by a rapid serum antibody response. More than 50% of pigs had seroconverted by week 10. At slaughter, 30.8% of investigated animals were still found to be seropositive by ELISA. Of the 60 study animals 39 were found positive by faeces PCR (65.0%), 49 animals were found positive by serology (81.7%), and 35 pigs (68.6%) had positive results by IHC at necropsy. All but one pig were found to be L. intracellularis infected by at least one of the three methods (98.3%). In conclusion, this is the first field study revealing the presence of prominent histological lesions characteristic for L. intracellularis infection and associated positive pathogen specific PCR and immunohistological results even in subclinically infected pigs. Although intestinal alterations disappeared after 3-4 weeks, L. intracellularis was detected by IHC for a longer time, especially in intestinal lymph nodes.

Pulmonary aspergillosis in an African elephant (Loxodonta africana)

A 26-year-old female African elephant (Loxodonta africana) with a history of purulent pododermatitis, recurrent abdominal pain, and severe weight loss died spontaneously after a period of deteriorating disease. The main pathological finding was a severe bilateral pyogranulomatous, partially necrotizing pneumonia with numerous intralesional fungal hyphae. At microbiological examination Aspergillus spp. were isolated. The present case indicates that mycotic pneumonia should to be considered as a differential diagnosis of pulmonary disorders in elephants.

[Swinepox--skin disease with sporadic occurrence]

Swinepox virus infection results in an acute, mild or subclinical course and is characterised by typical poxvirus skin lesions in affected pigs. Additionally, sporadic vertical swinepox virus transmission leads to congenital generalised infection and subsequent abortion or stillbirth. The present report describes the occurrence of epidermal efflorescences in two piglets after intrauterine natural suipoxvirus infection. No clinical abnormalities of the gilt and littermates as well as in other pigs from this herd were present. One of the affected piglets was stillborn and submitted for necropsy, the other animal was alive at birth, but died 3 days later. Histologically, a proliferative to ulcerative dermatitis with epithelial ballooning degeneration and characteristic intracytoplasmatic inclusion bodies was observed. The pathomorphological and histopathological suspected diagnosis of a poxvirus infection was confirmed by electron microscopy. Furthermore, the agent was identified as suipoxvirus by polymerase chain reaction. As demonstrated here, obvious skin lesions in suipoxvirus infection leads to a suspected diagnosis in newborn piglets on macroscopic examination. However, further post mortem examinations, including electron microscopy as well as molecular techniques are essential for the identification of the aetiology and the exclusion of differential diagnoses. Because the disease only affected two pigs there was only a small economic loss. A valid diagnostic plays an important role in advising farmers and for herd health monitoring.

Identification of a novel virulence determinant with serum opacification activity in Streptococcus suis

Streptococcus suis serotype 2 is a porcine and human pathogen with adhesive and invasive properties. In other streptococci, large surface-associated proteins (>100 kDa) of the MSCRAMM family (microbial surface components recognizing adhesive matrix molecules) are key players in interactions with host tissue. In this study, we identified a novel opacity factor of S. suis (OFS) with structural homology to members of the MSCRAMM family. The N-terminal region of OFS is homologous to the respective regions of fibronectin-binding protein A (FnBA) of Streptococcus dysgalactiae and the serum opacity factor (SOF) of Streptococcus pyogenes. Similar to these two proteins, the N-terminal domain of OFS opacified horse serum. Serum opacification activity was detectable in sodium dodecyl sulfate extracts of wild-type S. suis but not in extracts of isogenic ofs knockout mutants. Heterologous expression of OFS in Lactococcus lactis demonstrated that a high level of expression of OFS is sufficient to provide surface-associated serum opacification activity. Furthermore, serum opacification could be inhibited by an antiserum against recombinant OFS. The C-terminal repetitive sequence elements of OFS differed significantly from the respective repeat regions of FnBA and SOF as well as from the consensus sequence of the fibronectin-binding repeats of MSCRAMMs. Accordingly, fibronectin binding was not detectable in recombinant OFS. To investigate the putative function of OFS in the pathogenesis of invasive S. suis diseases, piglets were experimentally infected with an isogenic mutant strain in which the ofs gene had been knocked out by an in-frame deletion. The mutant was severely attenuated in virulence but not in colonization, demonstrating that OFS represents a novel virulence determinant of S. suis.

The regression of a canine Langerhans cell tumour is associated with increased expression of IL-2, TNF-alpha, IFN-gamma and iNOS mRNA

Canine cutaneous histiocytoma is a benign epidermal neoplasm of Langerhans cell origin, which usually displays spontaneous regression. Based on the degree of lymphocytic infiltration, 30 histiocytomas were classified into four groups representing different stages of tumour regression. To elucidate further the mechanisms of the antitumour immune response CD3+, CD21+, CD4+, CD8+ and myeloid/histiocyte antigen+ inflammatory cells were differentiated by immunohistochemistry and quantified. In addition, the number of apoptotic cells was detected using the TdT-mediated biotin-dUTP nick-end labelling (TUNEL) method. Furthermore, the expression of interleukin- (IL-2), IL-12(p40), tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), IL-10 and transforming growth factor-beta (TGF-beta) as well as inducible nitric oxid synthase (iNOS) mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR). Phenotyping of inflammatory cells revealed a significantly increased infiltration of all lymphocyte subsets and myeloid/histiocytic cells with the onset of tumour regression. The latter was significantly correlated to up-regulation of IL-2, TNF-alpha, IFN-gamma and iNOS mRNA expression. Expression of remaining cytokines and percentage of apoptotic cells showed no group-specific changes. The results indicate an initial infiltration of CD4+ T cells followed by increased expression of Th1 cytokines and recruitment of antitumour effector cells as the principal mechanism for tumour regression. Canine cutaneous histiocytoma is a unique example for an effective immune response in a naturally occurring neoplasm derived from epidermal Langerhans cells and might represent a valuable animal model to investigate tumour immunity.

[Canine distemper virus--an agent looking for new hosts]

Canine distemper is caused by the canine distemper virus (CDV), a RNA virus belonging to the genus Morbillivirus of the family Paramyxoviridae. The genus Morbillivirus includes measles virus, Rinderpest virus and peste-des-petits-ruminants virus. The host spectrum of CDV, which includes numerous families of Carnivores, has been changed in the last years and distemper-like diseases have been observed in numerous other species. These include epidemics in large felids, marine mammals and javelinas. Different viruses have been isolated from pinnipeds including a seal-specific isolate, termed phocine distemper virus 1, PDV-1, and a CDV strain, named PDV-2. Retrospective analysis of previous epidemics among marine mammals in various regions of the world provide evidence for the occurrence of so far unrecognized morbillivirus epidemics. In some including the mass mortalities of Baikal and Caspian seals and of large felids in the Serengeti, terrestrial carnivores including dogs and wolves have been suspected as a vector for the infectious agent. However, in other epidemics among marine mammals the source of infection remains unknown including both seal epidemics in northwestern Europe in 1988 and 2002. It remains to be determined whether a morbillivirus from other marine mammals or terrestrial carnivores caused the infection in this unprotected seal populations.