Isolation of Listeria monocytogenes from goat cheese associated with a case of listeriosis in goat.

Listeria monocytogenes was isolated from the brain of a goat, which was euthanized due to listeriosis. A few weeks later a similar subtype of L. monocytogenes was isolated from an on-farm manufactured fresh cheese which did not contain any milk from the goat which had suffered from listeriosis. A similar subtype was also found on 1 of the shelves in the refrigerator where cheeses were stored. Prior to the onset of listeriosis, 1 fresh cheese had been made of milk from the actual goat, which may have excreted L. monocytogenes in her milk. Thus, the cheese made of this milk may have contaminated the shelves in the refrigerator which then has served as a Listeria reservoir for new cheeses during several weeks.

Listeriosis--history and actual developments.

Although apparently observed before, the history of listeriosis dates back approximately 60 years. First known as a cause of epidemics and sporadic cases in some 50 species of animals, the disease appears now with increased frequency among human populations at risk. The causative agent Listeria monocytogenes is primarily a psychrophilic soil-borne bacterium with a wide pathogenic potential thus provoking primarily septicemia, meningitis and intrauterine infections. Recent observations indicate certain types of food being the principle vehicle for transmission of human listeriosis. This would parallel the epizootic situation in domestic animals. Further studies of the mechanisms leading to clinical and subclinical infections are just as necessary as reliable methods to determine the immunity status of individuals at risk.

Modern taxonomy of the Listeria group relationship to its pathogenicity.

Listeria monocytogenes is divided into serovars 1-7 (including subserovars) which belong to several genospecies as determined by gene homology studies. At least two of the five genomic species of L. monocytogenes are avirulent and cannot be separated by serological analysis from virulent strains. During the past two decades, several thousand Listeria strains have been analysed by the reference laboratory of the Institute of Hygiene in Würzburg, Germany. A study of the origin of the strains and their association with disease in animals and man in conjunction with biochemical and serological methods, allowed the separation of at least one group which is apathogenic and non-virulent to laboratory animals under ordinary test conditions. This apathogenic species, L. innocua should be separated from L. monocytogenes when Listeria-like strains are isolated from environmental sources.

[Problems in diagnostics of histoplasmosis (author's transl)]. / Probleme der Diagnostik bei Histoplasma-Mykose.

This report deals with three observations of Histoplasma mycosis (one acquired in Western Africa - large cell form; two in the USA - classical form) which were diagnosed from 10 to 35 years after primary infection. The laboratory diagnosis was based on immunological, histopathological and clinico-epidemiological data, since in none of the cases material was available for mycological culture. The histoplasmin skin test is considered to be the most sensitive procedure. A positive outcome may support other evidence or suspicion and may deliver an valid clue - particularly among individuals from non-endemic areas-to consider the possibility of Histoplasma infection. The demonstration of serum antibodies may assist in establishing a correct diagnosis in such cases.

[Nonpathogenic listeriae: L. innocua sp. n. (Seeliger et Schoofs, 1977) (author's transl)]. / Apathogene listerien: L. innocua sp. n. (Seeliger et Schoofs, 1977).

In connexion with the separation of Listeria innocua (Seeliger and Schoofs, 1977) from Listeria monocytogenes (Murray et at., Pirie, 1940), resulting epidemiological and epizootological problems are discussed. L. innocua is apathogenic when conventional experimental models for testing Listeria monocytogenes are used. Under special conditions, i.e. use of suckling mice, strain Welshimer of L. innocua produced localized encephalitis (Patocka et al., 1979). The peculiarities of L. innocua justify further studies at the immunological, infectious-pathological and genetical level. A description of the new species is given in the appendix of this paper.

[Internal mycoses of exogenous origin (author's transl)]. / Exogene Mykosen der inneren Organe (Systemmykosen).

The increase of both visceral mycoses and designations used for them requires, among other matters an accord on a better non-ambiguous terminology. The disease designation "blastomycosis" is quite obsolete and should be replaced by proper terms such as candida mycosis, cryptococcus mycosis, histoplasma mycosis etc. The frequently used term "systemic mycosis" should be restricted to exogenous mycotic infections of internal organs caused by obligatory pathogenic fungi such as Coccidioides immitis, Histoplasma capsulatum and others. The common term "endomycosis" is considered appropriate for fungal infections provoked by secondary disease provoking fungi of opportunistic pathogenicity especially by species of the form genus Candida. Other mycotic infections of visceral organs, mainly of the respiratory tract f.i. by species of Aspergillus and other molds, are likewise mostly of secondary nature and should not be considered as systemic mycosis in the restricted meaning of the word because of their lacking tendency to dissemination.

[Prevention of mycoses caused by yeasts]. / Verhütung von Mykosen durch Sprosspilze.

The wide-spread ubiquitous occurrence of molds and great masses of aerial spores (conidia, arthrospores etc.) as well as of yeast species with facultative pathogenicity, renders prophylaxis of respective human infections caused by such opportunists, rather difficult. Suppression of such fungi and continuous surveillance of endangered patients require considerable efforts and costs. Adequate control is particularly cumbersome in Candida infections, since the causative yeasts may be considered as "normal" commensals of the mucous membranes in many individuals. Overt secondary infections are frequently of endogenous origin, hence the name "endomycoses" as introduced by Gemeinhardt (1976). Under particular conditions such as care for patients with extended burns, or patients after bone-marrow transplantation or irradiation of the whole body, or patients after joint surgery, the complete elimination of yeasts is just as essential as the antibacterial decontamination over a limited period of time. In other groups of individuals similar drastic measures of control against Candida albicans are not deemed necessary. Reduction of local Candida cell counts to amounts below the individual level of tolerance may be deemed sufficient. Since the level of tolerance is, however, extremely low in infants and in many patients of the intensive care wards, especially in cases of malignant immunocytomas and leukemias of various nature, prophylaxis by proper hygienic measures and eventual preventive antimycotic treatment is an integral part of proper control.

Significance of immunological methods for diagnosis of fungal disease.

In the diagnosis of classical systemic mycoses, as caused by Blastomyces dermatidis, Coccidioides immitis, Histoplasma capsulatum and Paracoccidioides brasiliensis, serodiagnostic procedures in conjunction with skin tests are of significant diagnostic and prognostic value. The diagnosis of aspergillus mycosis is facilitated greatly by serological tests and the same is true for recognition of cryptococcus mycosis by means of serological detection of the cryptococcal antigen. Great progress has also been made in the evaluation of Candida antibodies in patients' sera.

Cryptococcosis: a diagnostic challenge.

Human cryptococcosis is an exogenous human infection of increasing frequency and growing importance. Early diagnosis is essential for the clinical outcome, no matter whether the infection is primary or secondary to underlying disease. Reliable and quick diagnostic methods are outlined and some pitfalls are discussed. Direct microscopy is essential, followed by cultivation procedures and serologic tests.

Listeria monocytogenes infections--therapeutic possibilities and problems.

Listeriosis in humans is a rare disease, which, however, is known to be epidemic and endemic. The prognosis has remained unsatisfactory up to today, the fatality being at least 10% and often considerably higher depending on the clinical features of the disease and the patient's age. Three population groups are at risk: pregnant women, fetuses and newborn infants. Furthermore, immunosuppression in older patients due to disease, therapy, or age also plays a role. The incidence of Listeria infections in patients over 45 is clearly increasing. Due to the nature of the pathogen (in vivo bactericidal concentrations of antibiotics are often not attainable; intracellular growth) a high dosage of ampicillin is recommended. Although the present therapeutic possibilities are not satisfactory, a combination of ampicillin and an aminoglycoside appears to be the best therapy at present. Other combinations such as rifampicin and beta-lactam antibiotics have exhibited in vitro antagonism. The preferred therapy, ampicillin, can only be recommended with reservations because it is not optimally effective.

[Hemolytic effect of Listeria innocua on sheep erythrocytes]. / Hämolysewirkungen durch Listeria innocua auf Schaferythrozyten.

The influence of culture medium composition on hemolytic effects produced by Listeria innocua on sheep blood agar has been investigated. Neither alpha- nor beta-hemolysis could be observed around L. innocua colonies grown on sheep erythrocyte agar lacking glucose. However, green zones of hemolytic phenomena were observed around colonies grown on such agar which contained 0,6% (w/v) glucose. By using L. innocua cell suspensions and culture filtrates this glucose-associated hemolysis only occurred in media which were weakly buffered (1 m M Na-PBS). This hemolytic phenomenon was attributed to the resulting acidification of the culture medium caused by the metabolic breakdown of glucose by Listeria. The results of this study demonstrate the necessity of including adequate buffer conditions when assaying the hemolytic property of a Listeria strain. It was found that the addition of 20 mM Na-PBS to the assay medium was sufficient to eliminate artificial "acidic-hemolysis". Moreover, the hemolysis observed with known hemolytic Listeria strains was unaffected by this buffering, as was in fact the case even when conditions of higher buffering capacity were employed. By testing in this manner, no evidence has been found which would suggest the existence of an hemolysin, either intra- or extracellular, produced by Listeria innocua. An accurate method for the determination of hemolysis caused by strains of the genus Listeria is proposed. This method of assaying hemolysis in a liquid grown medium has proven effective in determining the hemolytic properties of strains which appeared negative or questionable on blood agar as well as strains which in virulence tests were negative. The ability to accurately assess the hemolytic properties of Listeria strains, is essential in determining the association of Listeria hemolysin with pathogenicity of this genus. Together with current investigations on the genetics of hemolysin production by Listeria the determination of hemolytic activities will eventually allow to understand better the pathogenic principle of hemolytic strains of Listeria monocytogenes.

[Preventive measures for the control of fungal infections in the clinic]. / Vorbeugemassnahmen zur Bekämpfung von Pilzerkrankungen in der Klinik.

Hospital acquired infections due to fungi are primarily caused by yeast species of the genus Candida and mould species of the genus Aspergillus. Underlying disease with severely impaired defence mechanisms as well as certain forms of immunosuppressive and aggressive chemotherapy are the most important prerequisites for such secondary fungal infections. Aspergillus spec. usually infect man via exogenous routes, whereas Candida spec. mostly originate from the patient's own microbial flora. Under certain circumstances invasion of tissues follows (endomycoses). Exogenous Candida infections may likewise occur through contaminated hands of personnel and medical devices. The density of yeast cell distribution in hospital wards decreases with the distance from the primary source: the Candida infected human patient. Preventive measures protecting the patient at risk include: Permanent surveillance by routine cultural and serological examinations for the detection of an early infection of the skin, mouth, oesophagus, urinary tract, vagina and the bowel. Monitoring of patients is essential for early detection of dissemination and contributes to the control of fungal decontamination measures. Selective local decontamination is effected by the use of nonabsorbable compounds such as nystatin and amphotericin B in the gastrointestinal tract, and in oral and genital mucous membranes. Oral administration of ketoconazole has also been recommended. For the disinfection of skin appropriate chemicals are available. In the control of the environment of the endangered patient special attention must be paid to meticulous management of catheters.(ABSTRACT TRUNCATED AT 250 WORDS)

[Prevention of fungal infections in hospitalized patients]. / Vorbeugemassnahmen zur Bekämpfung von Pilzerkrankungen in der Klinik.

Hospital acquired infections due to fungi are primarily caused by yeast species of the genus Candida and mould species of the genus Aspergillus. Underlying disease with severely impaired defence mechanisms as well as certain forms of immunosuppressive and aggressive chemotherapy are the most important prerequisites for such secondary fungal infections. Aspergillus spec. usually infect man via exogenous routes, whereas Candida spec. mostly originate from the patient's own microbial flora. Under certain circumstances invasion of tissues follows (endomycosis). Exogenous Candida infections may likewise occur through contaminated hands of personnel and medical devices. The density of yeast cell distribution in hospital wards decreases with the distance from the primary source: the Candida infected human patient. Preventive measures protecting the patient at risk include: Permanent surveillance by routine cultural and serological examinations for the detection of an early infection of the skin, mouth, oesophagus, urinary tract, vagina and the bowel. Monitoring of patients is essential for early detection of dissemination and contributes to the control of fungal decontamination measures. Selective local decontamination is effected by the use of nonabsorbable compounds such as nystatin and amphotericin B in the gastrointestinal tract, and in oral and genital mucous membranes. Oral administration of ketoconazole has also been recommended. For the disinfection of skin appropriate chemicals are available. In the control of the environment of the endangered patient special attention must be paid to meticulous management of catheters. These measures are to be supported by careful disinfection policy concerning the hands of personnel and medical equipment.(ABSTRACT TRUNCATED AT 250 WORDS)

[Distribution of species of the genus Listeria]. / Distribution des espèces du genre Listeria.

Within the classification of different Listeria species according to present knowledge, this study investigates the sources and distribution of both the known "classical" species of Listeria as well as the recently added species: L. monocytogenes, L. innocua, L. ivanovii, L. welshimeri, L. seeligeri, L. grayi and L. murrayi. For this purpose 573 isolates from the environment, food, healthy carriers and patients suffering from listeriosis were selected out of a total of approximately 6000 strains originating from all parts of the globe which are maintained at the Listeria Culture Collection of the Institute of Hygiene, Würzburg. The selection was made according to the criterium of widest possible geographic distribution. The results indicate the environment to be the natural reservoir of all of the 7 'new' Listeria species. Healthy animal carriers harbour in their intestinal tract all species of Listeria with the exception of L. murrayi, whilst in the excreta of healthy individuals only the species L. monocytogenes, L. ivanovii, and L. innocua were found. Identification of strains from pathological specimens of human and animal origin resulted invariably in the finding of L. monocytogenes or L. ivanovii. L. grayi (7 strains) was found sporadically in Europe and in the USA, whereas L. murrayi (9 strains) has been isolated only in the USA. 26 of 28 so far known strains of L. welshimeri originated from the USA, and only 2 strains of this species were found in Europe. L. seeligeri (80 strains) was identified among European isolates, L. innocua, however, in both USA and Europe. L. ivanovii occurs in Australia, Europe and the USA. L. monocytogenes is of global distribution. Table 1 presents a survey of species, serovariety and origin of the 573 isolates. As both pathogenic and non pathogenic listeria strains are found in the human environment, it is necessary to identify each isolate appropriately, particularly in view of the elucidation of the rather obscure epidemiology of human listeriosis.

Aldo Castellani--an appraisal of his life and oeuvre.

Aldo Castellani was one of those pioneers who initiated breath-taking discoveries and progress in medical sciences during the early years of this century with great personal engagement and courage. His striking findings, such as the so-called Absorption-Test, the introduction of multiple vaccination, or the exploration of sleeping sickness and the discovery of Trichophyton rubrum, were achieved before he was even 35 years old. He received acknowledgement as a physician and lecturer. Many of his disciples and coworkers became first rate scientists, owing a lot to his encouraging personality. Castellani's straight forward character endeared him to many famous contemporaries. His uncompromising nationalism for Italy on the other hand arouse astonishment and aversion. His involvement in three wars again and again, rendered scientific researches and work difficult.

Incidence of Listeria monocytogenes in nature.

During a research project on the occurrence of Listeria monocytogenes 194 strains were isolated in southern West Germany during the years 1972 to 1974:154 from soil and plant samples (20.3%), 16 from feces of deer and stag (15.7%), 9 from old moldy fodder and wildlife feeding grounds (27.2%), and 8 from birds (17.3%). The highest number of isolates was obtained from uncultivated fields. The beta-hemolytic serovars 1/2b and 4b were were predominant; other serovars (some of them identified for the first time), including nonhemolyzing strains, have been encountered frequently. It is suggested that Listeria monocytogenes is a saprophytic organism which lives in a plant-soil environment and therefore can be contracted by humans and animals via many possible routes from many sources.