Experimental adiaspiromycosis of the common vole (Microtus arvalis) and other small wild mammals after intraperitoneal inoculation

After intraperitoneal inoculation ofE. crescens to nine species of wild small mammals, six species of rodents (Apodemus flavicollis, A. sylvaticus, Clethrionomys glareolus, Microtus agrestis, M. arvalis, Mus musculus) developed generalized adiaspiromycosis. The course of experimental infection corresponded to the infections of laboratory animals provoked in the same manner of inoculation. The authors studied the affliction of individual organs, the dynamics of growth of adiaspores in the organs of the abdominal cavity and in the lungs and followed up morphological changes in the adiaspores. In fresh cover glass preparations, the presence of manifestations was demonstrated justifying considerations on the capacity of multiplication of the adiaspiromycosis agent in the host organism.     

Antigenic activity of emmonsia crescens mutants

The antigenic properties of 3 UV mutants of Emmonsia crescens Emmons et Jellison 1960 were compared with the original wild strain, further with other 13 E. crescens strains, with E. parva, E. brasiliensis, E. ciferrina and Chrysosporium pannorum.For this purpose the strains were used for the immunisation of 70 rabbits. The formation of specific IgM- and IgG-antibodies was examined in their blood by means of several serologic reactions, and the capability of sensitizing the organism was proved by means of skin tests.All strains stimulated the formation of specific antibodies and sensibilised the macroorganism but in various extent. The differences in the antigenic activity was found not only among the single species but also among the single strains of the same species.All three mutants of E. crescens induced the formation of the specific antibodies but weaker than the virulent strains. They elicited, however, stronger and better reliable skin reactions than the virulent strains.The dimorphic fungus Emmonsia crescens Emmons et Jellison 1960 a causative agent of adiaspiromycosis is variable as in the saprophytic as in the parasitic phase of the life cycle. The cultures of strains isolated from different host animals can be morphologically disparate (13). They grow at various rates and they form the adiaspores of different sizes (1, 2, 19).The mutants of E. crescens induced by UV radiation possess especially a much greater variability: they differ from the wild strain by the morphology of the colony, by the rate of the growth, by the conidiation and by the virulence (6), which is associated with the capability of conversion in the morphologically perfect adiaspores (7). The size of these adiaspores in the granulomas of the hosts is in correlation with the growth rate of the mycelial stage of the mutants in vitro (5).We were interested in the antigenic properties of E. crescens mutants. Thereupon we tried to determine the. antigenic activity of avirulent mutants as well as those with a significantly decreased virulence and compare it a) with the original wild strain, b) with the different strains of E. crescens and c) with the strains of related species: E. parva, E. brasiliensis, E. ciferrina and Chrysosporium pannorum.     

Influence of animal hibernation on the development of mycoses

The development of adiaspiromycosis and trichophytosis depending upon the state of activity of redcheeked squirrels is described. The conidia of Chrysosporium (Emmonsia) parvum var. crescens, are not transformed into adiaspores when injected into hibernating animals. During the hibernation period of four months, most of the conidia die. After awakening, the remaining viable conidia are transformed into adiaspores. During hibernation the squirrels, which had been infected with Trichophyton mentagrophytes var. granulosum, developed a symptom-free infection.     

L'adiaspiromycose par Emmonsia crescens chez les petits mammifères sauvages en France

Résumé Dans le cadre d'un travail d'ensemble sur les petits mammifères sauvages en tant que réservoirs de germes pour un certain nombre d'anthropozoonoses, les auteurs ont recherché les adiaspores d'E. crescens dans les poumons de près de 3.000 pertits mammifères sauvages, en provenance de 45 départements français par la méthode d'homogénéisation-digestion précédemment décrite. Ces animaux appartiennent à 52 espèces de carnivores, rongeurs, insectivores et chiroptères.Les pourcentages moyens d'infection révèlent que l'adiaspiromycose des petits mammifères sauvages semble être une affection banale en France.Il existe cependant une variation dans l'intensité et la fréquence du parasitisme selon l'espèce, la famille, parfois l'ordre considérés. Ainsi, aucune des 109 chauves-souris examinées, appartenant à 17 espèces différentes, n'a été trouvée porteuse d'adiaspores. Les pourcentages d'animaux parasités varient, dans les autres ordres, de 0 à 50% selon les espèces.Le climat, la période de l'année, l'altitude ne semblent pas influer sur l'existence de cette parasitose.

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Within the framework of investigation on small wild mammals concerning the carrier stage of microorganisms in a certain number of anthropozoonoses, the authors investigated for adiaspores ofEmmonsia crescens the lungs of almost 3,000 small wild mammals from 45 departments of France by means of the method of homogenisation-digestion. The mammals belonged to 52 species of carnivors, rodents, insectivors, and chiropters. The mean percentage of infection revealed, that the adiaspiromycosis of small wild mammals is a banal affection in France. There is, however, a variation in intensity and frequency of parasitism according to species, family, sometimes according to order. None of the 109 bats, belonging to 17 different species, was found as carriers of adiaspores. The percentage of animals infected in the other orders varied between 0 to 50 per cent according to species. The climate the period of the year, the altitude do not appear to influence the existence of this parasitism.

     

Mutants ofEmmonsia crescens — Their pathogenicity and size of adiasporesin vivo

The pathogenicity of seven morphological mutants ofEmmonsia crescens was tested by means of intraperitoneal inoculation in mice. All mutants caused adiaspiromycosis. Adiaspores were isolated from granulomas after 2 months and their diameters were determined. Adiaspores from granulomas caused by five mutants (M-5, M-6, M-8, M-9 and M-16) were significantly smaller than adiaspores from granulomas caused by the wild strain, from which the mutants were derived. Two mutants (M-6 and M-9) produced adiaspores of the smallest diameter (130.5 and 119.9 μm) with the lowest variance of values, differing thus most from the original wild strain with adiaspores of 230.4 μm in diameter. A positive correlation was found between the size of the adiasporein vivo and growth rate of the mycelial stage ofEmmonsia crescens in vitro. The mutation characterized by the decreased growth rate of the mycelial stage is pheno-typically manifested in the adiasporic stage of the life cycle ofEmmonsia crescens, i.e. by the smaller average size of adiaspores in granulomas.     

Adiaspiromycosis in large free living carnivores

Adiaspiromycosis was identified in 6 animals in the examination of the lungs of 90 large carnivores. Emmonsia crescens (Chrysosporium parvum var. crescens) was demonstrated as the causative agent in 5 cases of disease — in the badger (Meles meles), the otter (Lutra lutra) and the fox (Vulpes vulpes). E. parva was demonstrated in the remaining case of disease in a fox. The badger is a new, up to the present unknown host of E. crescens. The sporadic occurrence of adiaspiromycosis in the fox and the otter classifies this disease among rare diseases of these animals.     

Importance of free living mustelid carnivores in circulation of adiaspiromycosis

The study of adiaspiromycosis in 8 species of free living mustelid carnivores (266 specimens) revealed the average intensity of infection to be 41.4%. The highest incidence rate was found in the exoanthropic species Putorius eversmanni (73.1 %) and Martes martes (72.2%) while the lowest was observed in the hemisynanthropic species Putorius putorius (30.6%). The stone marten (Martes foina) is a new, still unknown reservoir host of C. parvum var. crescens, C. parvum for which Putorius eversmanni and Mustela nivalis are new hosts, was also demonstrated in 3 cases. In the present paper, the role of mustelid carnivores in natural foci of adiaspiromycosis is discussed and evaluated. The importance of these predators in the circulation of C. parvum var. crescens is relatively wide. They make possible the liberation of adiaspores from the lungs of their prey — primarily small mammals — into the environment and participate in the spread of infection in both the horizontal and vertical directions. They play a part in the process of distributing of the organism to the vicinity of human dwellings, in the development of new elementary foci, and also act as important reservoir hosts of C. parvum var. crescens.     

Particularites de l'infestation adiaspiromycosique par Emmonsia crescens Emmons et Jellison, 1960 chez Pitymys subterraneus (De Selys-Longchamps 1836) et Mustela nivalis nivalis L. 1766

From the observation of some hundred lungs of small wild mammals in France, we have found two types of parasitism byEmmonsia crescens Emmons &Jellison, (1960). In most species, for example inApodemus sylvaticus andClethrionomys glareolus, the adiaspores ranged from 200 to 475 µ in diameter, their cell walls are 28 µ in average thickness and they cause a weak histological reaction in the parenchyma of the lungs. InPitymys subterraneus, the adiaspores are always much smaller, about 85 µ. They have a thin cell wall, 4 µ, and are surrounded by a strong histological reaction, the thickness of which ranges from 130 to 140 µ. The adiaspores observed inMustela nivalis nivalis are still smaller, about 70 µ, and they provoke a pulmonary reaction a hundred µ thick. However, we think that these small adiaspores belong to the speciesEmmonsia crescens Emmons &Jellison, (1960):

1. they germinate springing many mycelian tubes.
2. the macroscopic and microscopic morphological characteristics of the mycelian phase are identical to those of several strains ofEmmonsia crescens.
3. the mycelian phase completely turns into the yeast phase at 37° C on “Brain Heart Agar” Difco.
4. a strain isolated from aP. subterraneus, inoculated to a white mice, a bank vole or a field vole gives big adiaspores typical ofE. crescens in their respective lungs.
5. from an epidemiologic point of view, it is difficult to imagine such a narrow cohabitation of two species of so non specific germ having each its own host.

     

Natural variability in the mycelial form of emmonsia crescens

A range of variations in colony characteristics and microscopical morphology of Emmonsia crescens Emmons & Jellison 1960 have been studied. A total of 13 strains of the mycelial stage of the fungus were examined in detail. The isolates originated from the lungs of 8 species of wild mammals collected in Czechoslovakia, Bulgaria, France and U.S.S.R. According to their colony appearance the strains were classified into 3 groups as follows: powdered, floccose and fluffy. The microscopic structure of the colonies was relatively unique, differences were found in the size of aleuries and the type of their walls. The morphological variability of E. crescens was not markedly influenced by host species or geographic origin of strains.     

Seasonal incidence of adiaspores of Emmonsia crescens emmons & Jellison 1960 in wildly living animals

Summary In a collection of rodents from one locality a remarkable irregularity of monthly incidence of lung adiaspores was observed. The highest frequency of infection was ascertained in animals captured in April and May. The authors consider this phenomenon to be important for the elucidation of the life cycle ofEmmonsia crescens in nature.     

The effect of fungizone on experimental adiaspiromycosis of laboratory mice

Summary In laboratory mice weighing about 25 g, with experimental infection of adiaspiromycosis, total inhibition of development of the parasitic phase of the agent of this mycosis is induced with Fungizone — Squibb in daily intraperitoneal administration of 0.03 mg (dissolved in 0.1 ml of isotonic saline). In autopsies carried out 10th, 20th and 30th day after an intraperitoneal inoculation of 1 ml suspension of the mycelial phase of two Czechoslovak isolates ofEmmonsia crescens Emmons &Jellison 1960, no elements of the parasitic phase — adiaspores were found in the organs of the treated mice. In control groups of the untreated mice, experimental infection developed which was demonstrated by macro- and microscopical controls of organs and by a successful recovery of the agent.     

Canadian species of sorex,Microtus and peromyscus infected with emmonsia

Summary A single shrew, trapped in 1957 near Lloydminster (Alberta, Canada) and found to be infected withEmmonsia, has been identified asSorex cinereus cinereus Kerr. This is the only recorded instance of adiaspiromycosis in a shrew trapped in the western hemisphere as well as the first reported anywhere in this species.The finding for the first time in Canada of adiaspores in the infected lungs of the large vole,Microtus agrestis is also recorded.In addition, evidence is presented to show that an alveolus can be invaded by more than one adiaspore ofEmmonsia.Assisted by a research grant from the Ontario Thoracic Society.     

Scanning electron microscopy of experimental adiaspiromycosis

Adiaspiromycotic granulomas of mice experimentally inoculated with fungusEmmonsia crescens Emmons et Jellison 1960 were examined by scanning electron microscopy. Their morphology, surface structures, and germinating adiaspores isolated from granulomas are described.     

Adiaspiromycosis in a European beaver from Sweden

An infection with the rare mycosis Chrysosporium parvum was diagnosed in a European beaver (Castor fiber) shot in northern Sweden. The animal was in normal body condition and no signs of disease were observed. In the lungs a large number of nodules, up to 5 mm diameter, were observed. A large number of adiaspores were observed in the interstitium of the lungs and in the mediastinal lymph node. A chronic inflammatory reaction dominated by mononuclear leukocytes and giant cells was observed around the spores. This is the first report of adiaspiromycosis (Chrysosporium parvum) in the European beaver.     

Evolution d'Emmonsia crescens agent de l'Adiaspiromycose en adiaspores dans le poumon de souris de laboratoire expérimentalement infestées avec la phase saprophytique du champignon

Résumé 140 souris de laboratoire ont été soumises à trois instillations nasales successives d'une suspension de nombreux aleuriospores et articles mycéliens d'E. crescens dans une solution physiologique. 6 à 12 d'entre elles ont été sacrifiées chaque jour la première semaine, puis chaque semaine le premier mois et enfin chaque mois jusqu'à 7 mois, pour suivre la transformation de la phase saprophytique en phase parasitaire dans le parenchyme pulmonaire.Il semble que seules les aleuriospores, et non les articles mycéliens, puissent évoluer, en adiaspores. Les éléments parasites augmentent de volume d'autant plus rapidement que l'on est plus prés du début de l'expérience.A 7 mois, les adiaspores atteignent un diamètre moyen de 320 µ. Elles semblent susceptibles de grossir encore très légèrement. Leur paroi se différencie en deux couches des la première semaine après l'infestation. La couche interne se développe considérablement vers la fin du deuxième mois; la paroi a alors une épaisseur moyenne de 20–25 µ qui restera ensuite constante.Tous les stades parasitaires observés sont également capables de redonner la phase saprophytique sur milieu de Sabouraud ou de Mathur.

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140 laboratory mice have been instilled nasally with a suspension of numerous aleuriospores and some mycelium ofE. crescens in physiologic serum. 6 to 10 were killed every day during the first week, then every week during the first month and every month until seven months, to observe the transformation of the saprophytic phase into parasitic one in the lungs. The aleuriospores only and not the mycelium seem to be able of evolution into adiaspores: the nearer to the beginning of the experience, the faster the development of parasitic elements. After seven months, the adiaspores reach an average diameter of 320 µ. They still seem able to grow a little. Their wall is differentiated into two layers as early as the first week after the infestation. The inner layer increases largely at two months; then the wall is 20–25 µ thick and does not increase ulteriorly. All the parasitic stages are able to give again the saprophytic phase on Sabouraud or Mathur agar.

     

Antimicrobial Resistance in Escherichia coli Isolates from Swine and Wild Small Mammals in the Proximity of Swine Farms and in Natural Environments in Ontario, Canada

Wild animals not normally exposed to antimicrobial agents can acquire antimicrobial agent-resistant bacteria through contact with humans and domestic animals and through the environment. In this study we assessed the frequency of antimicrobial resistance in generic Escherichia coli isolates from wild small mammals (mice, voles, and shrews) and the effect of their habitat (farm or natural area) on antimicrobial resistance. Additionally, we compared the types and frequency of antimicrobial resistance in E. coli isolates from swine on the same farms from which wild small mammals were collected. Animals residing in the vicinity of farms were five times more likely to carry E. coli isolates with tetracycline resistance determinants than animals living in natural areas; resistance to tetracycline was also the most frequently observed resistance in isolates recovered from swine (83%). Our results suggest that E. coli isolates from wild small mammals living on farms have higher rates of resistance and are more frequently multiresistant than E. coli isolates from environments, such as natural areas, that are less impacted by human and agricultural activities. No Salmonella isolates were recovered from any of the wild small mammal feces. This study suggests that close proximity to food animal agriculture increases the likelihood that E. coli isolates from wild animals are resistant to some antimicrobials, possibly due to exposure to resistant E. coli isolates from livestock, to the resistance genes of these isolates, or to antimicrobials through contact with animal feed.     

Epidemiological investigation of <Emphasis Type="Italic">eaeA</Emphasis>-positive <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Escherichia albertii</Emphasis> strains isolated from healthy wild birds

Escherichia coli has commonly been associated with diarrheal illness in humans and animals. Recently, E. albertii has been reported to be a potential pathogen of humans and animals and to be carried by wild birds. In the present study, the prevalence and genetic characteristics of intimin-producing E. coli and E. albertii strains were evaluated in wild birds in Korea. Thirty one of 790 Enterobacteriaceae strains from healthy wild birds were positive for the intimin gene (eaeA) and twenty two of the 31 strains were identified as atypical enteropathogenic E. coli (aEPEC) that did not possess both EAF and bfpA genes. A total of nine lactose non-fermenting coliform bacterial strains were identified as E. albertii by PCR and sequence analysis of housekeeping genes. A total of 28 (90.3%) eaeA-positive strains were isolated from waterfowl. Fifteen aEPEC (68.2%) and two E. albertii (22.2%) strains had a β-intimin subtype and 14 aEPEC strains harboring β-intimin belonged to phylogenetic group B2. AU eaeA-positive E. albertii and 3 aEPEC strains possessed the cytolethal distending toxin gene (cdtB). The eaeA-positive E. coli and E. albertii strains isolated from healthy wild birds need to be recognized as a potential pathogroup that may pose a potential threat to human and animal health. These findings indicate that eaeA-positive E. coli as well as E. albertii can be carried by wild birds, posing a potential threat to human and animal health.     

Wild birds and urban pigeons as reservoirs for diarrheagenic <Emphasis Type="Italic">Escherichia coli</Emphasis> with zoonotic potential

In order to describe the role of wild birds and pigeons in the transmission of shiga toxigenic Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) to humans and other animals, samples were collected from cloacae and oropharynx of free-living wild birds and free-living pigeons. Two STEC (0.8%) and five EPEC strains (2.0%) were isolated from wild birds and four EPEC strains (2.0%) were recovered from pigeons. Serogroups, sequence types (STs) and virulence genes, such as saa, iha, lpfA _O113, ehxA, espA, nleB and nleE, detected in this study had already been implicated in human and animal diseases. Multidrug resistance (MDR) was found in 25.0% of the pigeon strains and in 57.0% of the wild bird strains; the wild birds also yielded one isolate carrying extended-spectrum β-lactamases (ESBLs) gene bla _CTX-M-8. The high variability shown by PFGE demonstrates that there are no prevalent E. coli clones from these avian hosts. Wild birds and pigeons could act as carriers of multidrug-resistant STEC and EPEC and therefore may constitute a considerable hazard to human and animal health by transmission of these strains to the environment.     

Adiaspiromycosis of an Apodemus agrarius captured wild rodent in Korea

Adiaspiromycosis is caused by pulmonary infection with Emmonsia. Inhalated spores of Emmonsia cause asymptomatic infection to necrogranulomatous pneumonia, depending on the burden of adiaspore and host immunity. For disease monitoring of wild rodents captured on Jeju Island in Korea, we examined the lung tissue of wild rodents histopathologically. Spores composed of thick three-layered walls were found following histopathological examination and were diagnosed as adiaspiromycosis. Adiaspiromycosis has been found in mammals in many parts of the world. To our knowledge, this is the first report of adiaspiromycosis of an Apodemus agrarius captured in Korea.     

Reservoirs of <Emphasis Type="Italic">Brucella</Emphasis> infection in nature

Brucellosis is a zoonosis caused by bacteria of the genus Brucella, which includes nine species: B. melitensis (goats and sheep as the main reservoir hosts), B. abortus (cattle), B. suis (pigs), B. neotomae (desert woodrats), B. ovis (sheep), B. canis (dogs), B. ceti (whales), B. pinnipedialis (pinnipeds), and B. microti (Microtus voles). The epidemic and epizootic situation with brucellosis is accounted for by farm animals, which are the carriers of three main pathogens (B. melitensis, B. abortus, and B. suis). Their ubiquitous distribution is the factor determining global prevalence of the above Brucella species on all continents and in the overwhelming majority of countries. Consistent with the expansion of the pathogen ecological range are the 1990s findings of new Brucella species in marine mammals (whales and pinnipeds) and in some rodents. These bacteria proved to be also pathogenic for terrestrial mammals and humans. All Brucella-infected animals considered in the paper are tentatively divided into two groups. The first includes most of the wild and domestic animal species, birds, and ticks that acquire the infection farm animals, the main hosts of Brucella. The second group includes animals (wild reindeer, hares, bison, and probably saiga antelopes, dogs, and marine mammals) which may carry Brucella regardless of infection prevalence in the main hosts.