1 Fleas are wingless insects with a laterally compressed body of about 1.5-4 mm length. Like all insects they possess six legs and three body segments. Taxonomically they belong to the order Siphonaptera (Eckert et al. 2000) (Table 1). This family contains several species and subspecies. Fleas represent one of the most important ectoparasites (Mehl- horn 2000; Mehlhorn et al. 2001b). At the moment there are more than 2000 described species and subspecies throughout the world (Borror et al. 1981). These species belong to the families Pulicidae, including Pulex spp., Ctenocephalides spp., Spilopsyllus spp. and Archaeopsyllus spp., or the familia Ceratophyllidae with the genuses Ceratophyllus or Nosopsyllus to mention only some of the most important veterinary and human representatives. Fleas have a history of about 60 million years and were already found on prehistoric mammals. While becoming parasitic the original exterior of the two-wing insects, also designated as the order Diptera, has changed by losing the wings in the adults, whereas the larval form still has similarity with the larva of the order Diptera (Strenger 1973). About 95% of the -2000 different flea species parasitize on mammals, 5% live on birds. Table 1. Taxonomy of fleas Systematic Taxonomy Phylum Arthropoda Tracheata (=Antennata) Subphylum Classis Insecta (Hexapoda) Ordo Siphonapterida Familia Pulicidae Familia CeratophyUidae Genus Ctenocephalides. Genus Ceratophyllus. Nosopsyllus Pulex.

The genome of retroviruses contains three major coding regions for virion proteins, gag, pol and env. Gag encompasses information for nonglycosylated viral proteins that form the matrix, the capsid and the nucleoprotein structures. From pol derive reverse transcriptase and integrase, and env codes for the surface glycoproteins of the virion which consist of a transmembrane and a surface domain, linked by disulfide bonds. A viral protease is derived eitherfrom the gagorfrom the pol coding region, depending on the virus. Simple retroviruses contain only this elementary gag, pol, and env coding information. Once integrated, they are able to multiply efficiently, using the cellular transcriptional and replication machineries without intervention of viral transacting factors. Most oncogenic retroviruses belong in this category. Complex retroviruses, on the other hand, encode additional nonstructural proteins from multiply spliced messages. These proteins play important regulatory roles in the life cycle of the virus. They function as transacting factors that, in concert with cellular regulatory proteins, control viral gene expression and function and are essential components in the replication of complex retroviruses. To this category belong the lentiviruses, the spumaviruses and a group of oncogenic retroviruses that includes human T cell leukemia virus (HTLV) and bovine leukosis virus(BLV).

The recent rapid advances in our knowledge of immunological and virological mechanisms involved in the pathogenesis of viral heart disease makes it difficult for everybody working in this field to keep up with the latest developments. How ever, much of what we know is still circumstantial and only vaguely substained. Interdisciplinary understanding and cooperation thus seems necessary to get a better insight into the mechanisms by which viruses may initiate immunological organ-specific tissue injury and disease! This volume evolved out of an international symposium by the same title held on May 25. -28. , 1988 in Tegernsee, near Munich, of which a wide spectrum ofim munological, virological, diagnostical and clinical problems was covered. Both review articles and new experimental and clinical data are included in this volume to give the reader an up-to-date information about current concepts and future aspects. Chapter I serves as an excellent introduction to the epidemiology and natural history of dilated cardiomyopathy / viral heart disease. Although a definite viral etiology in myocarditis and dilated cardiomyopathy is often difficult to establish, epidemiological and serological data incriminate a viral etiology underlying many cases of "dilated cardiomyopathy". Chapters II and III describe the current think ing on virological and immunological mechanisms involved in the pathogenesis of viral heart disease. Among others virus topism, virus persistance, possible mecha nisms and genetic basis of post-infection autoimmunity, and the virus-interaction with the immune system are discussed.

In order to survive, bacteria must constantly monitor their structure and physiology. Adaptive behaviours are established by using environmental sensors and response regulators. These communication modules regulate a wide variety of signals including host detection and invasion, cell cycle, metabolite utilization, starvation and many others. The purpose of this volume is to give an overview of the various systems and to introduce recent advances in understanding selected systems of pathogenic bacteria.

During recent years there has been increasing interest in the value of a number of chemical and physical-chemical analytical methods for the detection and characterization of microorganisms. Furthermore, such methods are currently used in studies on microbial metabolic processes, on the role of microorganisms in the turnover of inorganic and organic compounds, and on the impact on environmental changes by microbial activity. Moreover, the introduction of some of these methods not only shortens the analytical time period compared to *'traditional" techniques, but also improves the analytical quality. Mass spectrometry (MS) combined with chromatographic inlet systems, particularly gas chromatography (GC), belongs to those methods which during recent years have established their value for the above-mentioned purposes. The present volume starts with basic chapters on the principles for MS and common inlet systems, particulary Gc. It discusses applications of these techniques to a number of microbiological disciplines, e.g., ecologi cal and medical microbiology. Emphasis is laid on organic compound classes vii viii / PREFACE of special relevance to microbiology, e.g., volatiles, lipids, amino acids, peptides and carbohydrates. Some compound classes of a more general biochemical rather than specific microbiological importance, e.g., steroids and nucleotides, are dealt with briefly. The editors wish to thank all those who have contributed to this book. We hope it will stimulate further research in this futuristic field and will be of practical value.

Borna disease was first described over 200 years ago, in what is now Southeastern Germany, as a fatal neurologic affliction of horses and was considered a curiosity for many decades. The causative agent was unknown, and the animal species infected in nature were limited to horses and sheep. Today, as described in this volume, the host range has extended to all warm-blooded animals, the genes and proteins of the virus have been identified, and many of the mechanisms responsible for behavioral disturbances are understood. Serologic studies suggest that BDV or related agents are likely to play a role in human neuropsychiatric diseases.

For decades this virus system has served--and continues to do so--to pioneer investigations on the molecular biology, biochemistry and genetics of mammalian cell systems. This three volume work presents an up-to-date account of recent basic research in one of the most important experimental systems for biochemical, cell biological, genetic, virological and epidemiological investigations in mammalian molecular biology. In this, the second of three volumes, the attention is turned to such topics as DNA replication, recombination and integration, and post-transcriptional control. The chapters have been written by an international group of leading experts in their respective fields of interest.

This completely revised, updated, and expanded edition has been neces sitated by the many important newer discoveries that have been made since the publication of the first edition. That volume contained almost 2000 references from the 1600s to 1953. Since then and after an extensive search, I have accumulated some 3800 additional titles from the world's literature on Paramecium. After certain titles that largely represented abstracts and preliminary reports that were followed by full research papers were eliminated, approximately 4400 full titles from the 1600s to the present were selected for inclusion in this edition. Most of the titles in the Bibliography are the more recent ones beginning with 1953. I consider the Bibliography an important part of the book: A good title of a paper in a journal is a minature abstract of its contents. Thus, the reader who may be interested in obtaining additional information not found in the book may refer directly to the original source. A cursory examination of the Bibliography will reveal that parame cium research has extended into all branches of biology, including bio chemistry and biophysics. Like other areas of science, paramecium research has become highly specialized and fragmented. I have attempted to organize and present the basic information in one book. Because of space limitations, some items may have been dealt with briefly. It is in such instances that the Bibliography will be found to be invaluable.

Dubos's classic biography of Louis Pasteur, originally published in 1960 and for several years out of print is once again made available in this new and expanded hardcover edition. The original work has been enlarged by more than forty illustrations and tables, a new biographical sketch of Dubos, a glossary of technical terms and a chronological outline of Pasteur's career. The book's enduring appeal is a tribute both to its subject and to its author. Few scientists so captured the public imagination as Louis Pasteur, and fewer still had such a dramatic effect on everyday life. Dubos, a Pulitzer prize winner, was a modern biographer almost ideally suited to the task. A distinguished French-born microbiologist of broad culture, Dubos had a deep appreciation for the power and enduring significance of Pasteur's scientific work. To the more personal dimensions of the biographer's task, Dubos brought his keen insight into the wellsprings of human action, behavior, and personality. He thus appreciated the full range of Pasteur's life, including its philosophical, religious, and political dimensions. Finally, Dubos' graceful writing style allowed him to convey the excitement and significance of even the most technical aspects of Pasteur's work.

CRISPR/Cas is a recently described defense system that protects bacteria and archaea against invasion by mobile genetic elements such as viruses and plasmids. A wide spectrum of distinct CRISPR/Cas systems has been identified in at least half of the available prokaryotic genomes. On-going structural and functional analyses have resulted in a far greater insight into the functions and possible applications of these systems, although many secrets remain to be discovered. In this book, experts summarize the state of the art in this exciting field.

Mounting evidence in the past decade indicates that innate immunity mediates functions above and beyond first-line defense against infection. It is now appreciated that innate immune mechanisms are critically involved in the development of adaptive immunity and, moreover, the regulation of diverse physiological and homeostatic processes. The latter explains why deregulation of innate immunity may lead to pathological disorders that are not necessarily or directly related to host defense. This Volume compiles the latest advances in this rapidly evolving field as presented by eminent scientists at the 7th International Aegean Conference on Innate Immunity in Rhodes, Greece. It includes topics related to the biology and function of Toll-like and other pattern-recognition receptors, complement and its crosstalk with other physiological systems, inflammatory mechanisms and diseases, natural killer cells, and the cooperative interplay between innate and adaptive immune cells. This book is an excellent source of information for researchers and clinicians with interests in immunology, host-microbe interactions, and infectious and inflammatory diseases.

rope it was mainly the states of the northern and centrat European areas which succeeded in achieving the extermi nation or at least the regression of brucellosis. (The origi nal plan to present the conditions in Asia and Oceania, in cluding Australia, in maps as weil, and thereby to achieve a comprehensive worldwide review of the known and as certainable distribution of brucellosis, was not, however, practicable. ) Information available from these parts of the world, especially from Asia, is so fragmentary that the great expense required for the compilation of the map did not seem justified. On the other hand it seemed desirable to collate and document these data which had been ac quired as a basis for future research. It is tobe hoped that, at a later date, when more comprehensive data become available, the Heidelberg Academy will be able to decide to support a cartographic presentation of the occurrence of brucellosis in these parts of the world as weil. Last, but not least, the intensive research carried out by bacteriologists had led to the discovery of new species of Brucella, such as B. ovis, B. canis and B. neotomae. Further types - such as Type 4 of B. suis which occurs in reindeer and caribou - were identified. Though these new species and types, which are undoubtedly to be classed with the brucellae, have achieved regional significance in places, the three dassie species B. melitensis, B. abortus and B."

Species of aspergilli are common in man's environment and are responsible for a wide spectrum of human and animal disease, ranging in animals from mycotic abortion to aflatoxicosis and in humans from localized colonization of the ear or skin to life-threatening systemic infection of neutropenic patients. In recent times, invasive aspergillosis has become increasingly important as a cause of morbidity and death, initially in patients receiving immunosuppression prior to organ transplantation, and latterly in haematologic patients rendered neutropenic by underlying disease or chemotherapy. In some centres, the condition has been recorded in more than 40% of patients dying with acute leukaemia. Laboratory diagnostic procedures are not always helpful and the diagnosis depends largely on clinical parameters. The clinician is faced with yet another problem, that of management. At present, antifungal therapy of invasive aspergillosis can be largely ineffectual, and the mortality rate remains unacceptably high. Since Aspergillus fumigatus was first described almost 125 years ago, several other pathogenic species have been recognized. The marked biosynthetic abilities and varied mechanisms of gene recombination of aspergilli have long commanded attention in food technology and genetics. Their equally varied abilities to cause disease have attracted the interest of toxicologists, allergists and physicians concerned with infectious diseases.

Retroviruses have been of great importance to biomedical science for the past half century. Initially, studies on oncogenic animal retroviruses provided important insights into molecular processes in carcinogenesis - most notably the existence and mechanisms of action of oncogenes and proto-oncogenes. Moreover, several human diseases are caused by retroviruses, including AIDS, adult T-cell leukemia and the neurological disease HAM/TSP. The topic of this volume is a relatively unknown animal retrovirus, jaagsiekte sheep retrovirus, the causative agent of transmissible lung cancer in sheep -ovine pulmonary adenocarcinoma. The disease was first documented in South Africa in the 1800s, it has a wide geographical distribution, and it is of economic importance in high endemic regions. However, until very recently the nature of the etiologic agent was unclear, and relatively few laboratories actively studied the disease.

Viral Vaccines Joseph L. Melnick As with history in general, the history of vaccines needs to be reexamined and updated. My task is to look back to see what has been successful and to look forward to see what remains to be accomplished in the prevention of viral diseases by vaccines. Also, I shall refer to the pertinent material discussed at two recent conferences of the Institute of Medicine, National Academy of Sciences, on virus vaccines under development and their target populations in the United States (1985b) and in developing countries (1986). These reports, plus a third on Vaccine Supply and Innovation (1985a), should be required reading for all those in both the public and the private sector who have a responsibility or interest in vaccines for the prevention of human disease. It has been through the development and use of vaccines that many viral diseases have been brought under control. The vaccines consist either of infectious living attenu ated viruses or of noninfectious killed viruses or subviral antigens. When we look at the record, it is the live vaccines that have given the great successes in controlling diseases around the world. Examples are smallpox, yellow fever, poliomyelitis, measles, mumps, and rubella."

The genus Bacillw; has a long history of importance, both from an economic point of view and as a source of experimental microorganisms. This volume critically reviews aspects of identification, molecular biology, and growth that are of impor tance for the current and anticipated future exploitation of members of this group. In addition, the volume includes a chapter on taxonomy, as the importance of good taxonomy is often not fully appreciated; on sporulation, since so many important products are produced concomitantly with this process and we are beginning to understand the mechanisms by which the process is controlled; and, finally, on the cell envelope, as we are only just beginning to appreciate the significance of dif ferences between the cell walls of gram-positive and gram-negative bacteria for productivity and processing. The commercial importance of Bacillus lies mainly in the area of enzyme pro duction for the food, drink, and detergent markets. Increasingly, however, the ability of Bacillus to secrete proteins, coupled with its regulatory acceptability, has resulted in strenuous efforts to develop species of Bacillus as hosts for the produc tion of value-added heterologous proteins. Difficulties have often been encoun tered, indicating a need to divert more resources to improving our understanding of the molecular biology of members of this grou p. Experience with Escherichia coli, a far from ideal organism from a commercial point of view, suggests that an in creased investment in Bacillus is likely ultimately to be productive.

This is the introductory volume of a new series to be issued under our general editorship. With the development of an unpre cedented increase in interest in comparative pathobiology, we are of the opinion and intent that Comparative PathobioZogy should become the focal point for the publication of definitive reviews and the proceedings of significant symposia in this area of modern biomedical science. Although the term is now in common use, the question is still sometimes raised as to what "pathobiology" includes. This broad area of modern biology includes but extends beyond traditional pathology. It also encompasses studies directed at understanding the biology, chemistry, and physics of infectious agents, in cluding how they contact and invade the effected organism; the reactions of hosts to such agents, as well as to abiotic invaders; the ecologic parameters which facilitate infection; and the development of tools essential for the understanding of hast pathogen interactions. In other words, pathobiology is inter disciplinary and incorporates all of those aspects of biology, chemistry, and physics which directly or indirectly permit greater understanding of the nature of infectious and noninfectious diseases and the possible implications of such in biomedicine, agriculture, and environmental science. By "comparative" is meant an analytical and critical evaluation of comparable processes as they apply to all categories of animals, invertebrates as well as poikilothermic and homeothermic verte brates."

The period between 1950 and 1980 were the golden unique insights into how pathological processes affect years of transmission electron microscopy and produced cell organization. a plethora of new information on the structure of cells This information is vital to current work in which that was coupled to and followed by biochemical and the emphasis is on integrating approaches from functional studies. TEM was king and each micrograph proteomics, molecular biology, genetics, genomics, of a new object produced new information that led to molecular imaging and physiology and pathology to novel insights on cell and tissue organization and their understand cell functions and derangements in disease. functions. The quality of data represented by the images In this current era, there is a growing tendency to of cell and tissues had been perfected to a very high level substitut e modern light microscopic techniques for by the great microscopists of that era including Palade, electron microscopy, because it is less technically Porter, Fawcett, Sjostrand, Rhodin and many others. At demanding and is more readily available to researchers- present, the images that we see in leading journals for This atlas reminds us that the information obtained by the most part do not reach the same technical level and electron microscopy is invaluable and has no substitute.

By 1977 it was clear that the thermophilic campylobacters were a major cause of acute bacterial enteritis. In response to that observation an international workshop was convened in Reading, England, and attracted over 130 participants. Many of these individuals resolutely returned for the eighth in the series of biennial international workshops, this time held in Win chester, England, in July 1995. All were surprised at the continued, and even expanding, re search effort in this narrow microbiological field. Such a lasting interest is undoubtedly a reflection of a consistent rise in the incidence of infection, the growing number of closely re lated organisms and disease associations, and an ever-increasing awareness by the public and government agencies of public health and food safety issues. The second workshop in Brussels in 1983 was a forum that demonstrated the growing awareness in the campylobacter community of the existence of campylobacter-like organisms and provided the platform for presentations describing the association of these organisms, now classified in the genus Helicobacter. with gastroduodenal disease. The clinical aspects of the research into helicobacters is now thoroughly covered in several other meetings, and the remit of the international workshop has been expanded to provide a forum for the presentation of the basic microbiological research carried out on these bacteria. In a continuation of this ap proach the remit of the workshop has been further extended to other related organisms, reflect ing that there are many other campylobacter-like organisms still to identify and characterize."

In response to the field's need for an introductory text, the authors have distilled the vast and scattered literature relating to the biotechnology of microbial secondary metabolites. General biology, biosynthesis, the search for novel metabolites, and techniques for strain improvement are all discussed to provide undergraduate and graduate students with a concise, readable overview of the field.

The 1st International Workshop on Acinetobacter was held on 6th September, 1986, in Manchester, England, in association with the 14th International Congress of Microbiology. That occasion was so well attended and productive that there were soon discussions about how, when and where the next meeting should be held. This time, however, there was sufficient confidence to think of a more substantial meeting and to plan for the proceedings to be published. It emerged that there was wide agreement that the time was ripe to take stock of the entire biology of Acinetobacter: its occurrence and taxonomy; its molecular biology, biochemistry and physiology; its clinical importance and its industrial and commercial applications. The 2nd International Workshop on Acinetobacter took place from 6th to 7th September, 1990, at the Institut Pasteur, Paris, and was sponsored by the Federation of European Microbiological Societies. There were about 100 participants from 19 countries. The backbone of the meeting consisted of 23 plenary lectures. There were 28 posters and the meeting closed with a general discussion which went on long after the official finishing time despite all the counter-attractions of a sunny Parisian Friday afternoon. Indeed discussions continued while cruising along the Seine and while dining at the top of the Tour Montparnasse. However, the vitality and usefulness of even the most successful meeting is difficult to transmit by the printed word.

The formation of atmospheric nitrogen gas by denitrifying bacteria may represent a significant nutrient sink in natural ecosystems. The rate of denitrification has often been difficult to measure in situ, however, and new methodologies should stimulate research on distribution of activity in space and time. The load of fertilizer nitrogen in modem agriculture has led to increasing nutrient reservoirs in recipient subsoils, aquifers, inland waters and coastal seas. By its conversion of nitrate to atmospheric nitrogen, bacterial denitrification is the only biological process to potentially reduce the impact of increasing nutrient loadings by fertilizer nitrogen in the environment. As part of a scientific program set up by the Danish Ministry of Environment to study environment cycling of nitrogen, phosphorous and organic matter (NPO program) in the light of agricultural, domestic and industrial activities, a symposium on DENITRIFICATION IN SOIL AND SEDIMENT was held at the University of Aarhus, Denmark from 6-9 June 19i\9. On the basis of lectures given at the symposium, this book contains a number of invited contributions on the regulation of denitrification activity (control of enzyme synthesis and activity) and measurement of in situ rates of denitrification in terrestrial and aquatic environments (control factors, diel and seasonal variations, etc). Emphasis has been placed on including the recent improvements in methodologies and current understanding of process regulation, however the book also contains examples of integrated research on the significance of denitrification in environmental nutrient cycling.

The genus Pseudomonas represents a large group of medically and envi ronmentally important bacteria. Interest in these bacteria is reflected in the extensive number of publications devoted to original research, re views, and books on this subject. In this volume selected areas of Pseu domonas research are presented in depth by persons who have been active in their fields over many years. The extensive reviews presented are an effort to provide a balanced perspective in a number of areas not readily available in the current literature. In the style of the previous Biotechnology Handbooks most of these topics have not been reviewed at all, and several are also presented from a new direction. For example, in addition to structural and compositional aspects, the chapter on lipids provides shifts in lipid parameters that result from environmental changes. This information will be invaluable to a cross section of Pseu domonas researchers in pathogenesis and bioremediation. The chapters presented include basic aspects of plasmid biology and carbohydrate metabolism and regulation. A major emphasis is placed on the Pseudomonas aeruginosa cell surface. Chapters cover lipo polysaccharide, capsular polysaccharide and alginate, the outer mem brane, transport systems, and the flagellum. Uptake of iron is also neces sarily an important portion of the chapter on iron metabolism.