University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Other Publications in Zoonotics and Wildlife Disease Wildlife Disease and Zoonotics December 1999 Bacterial Diseases (Field Manual of Wildlife Diseases) Milton Friend Follow this and additional works at: https://digitalcommons.unl.edu/zoonoticspub Part of the Veterinary Infectious Diseases Commons Friend, Milton, "Bacterial Diseases (Field Manual of Wildlife Diseases)" (1999). Other Publications in Zoonotics and Wildlife Disease. 12. https://digitalcommons.unl.edu/zoonoticspub/12 This Article is brought to you for free and open access by the Wildlife Disease and Zoonotics at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Other Publications in Zoonotics and Wildlife Disease by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Section 2 Bacterial Diseases Avian Cholera Tuberculosis Salmonellosis Chlamydiosis Mycoplasmosis Miscellaneous Bacterial Diseases Introduction to Bacterial Diseases 73 Inoculating media for culture of bacteria Photo by Phillip J. Redman Introduction to Bacterial Diseases “Consider the difference in size between some of the very tiniest and the very largest creatures on Earth. A small bacterium weighs as little as 0.00000000001 gram. A blue whale weighs about 100,000,000 grams. Yet a bacterium can kill a whale…Such is the adaptability and versatility of microorganisms as compared with humans and other so-called ‘higher’ organisms, that they will doubtless continue to colonize and alter the face of the Earth long after we and the rest of our cohabitants have left the stage forever. Microbes, not macrobes, rule the world.” (Bernard Dixon) Diseases caused by bacteria are a more common cause of whooping crane population has challenged the survival of mortality in wild birds than are those caused by viruses. In that subpopulation of cranes. Salmonellosis has become a addition to infection, some bacteria cause disease as a result major source of mortality at birdfeeders throughout the of potent toxins that they produce. Bacteria of the genus Nation, and mycoplasmosis in house finches has become the Clostridium are responsible for more wild bird deaths than most rapidly spreading infectious disease ever seen in wild are other disease agents. Clostridium botulinum, which causes birds. This disease reached the Mississippi River and beyond avian botulism, is primarily a form of food poisoning and it within 2 years of the 1994 index cases in the Washington, is included within the section on biotoxins (see Chapter 38). D.C. area. Other Clostridium sp. that colonize intestinal tissues produce Avian botulism has also expanded in geographic distri- toxins that cause severe hemorrhaging of the intestine, thus bution and has gained increased prominence as a disease of leading to tissue death or necrosis and intoxication of the waterbirds. It is undoubtedly the most important disease of bird due to the exotoxins produced by the bacterial cell. The waterbirds worldwide. Much of the geographic expansion descriptive pathology is referred to as a necrotizing gastro- of avian botulism has occurred during the past quarter- enteritis or necrotic enteritis and the disease as clostridial century. enterotoxemia. The classic example in gallinaceous birds such As a group, bacterial diseases pose greater human health as quail, turkey, pheasant, grouse, and partridge, is ulcer- risks than viral diseases of wild birds. Of the diseases ad- ative enteritis or quail disease, which is caused by Clostridium dressed in this section, chlamydiosis, or ornithosis, poses the colinium; quail are the species most susceptible to that dis- greatest risk to humans. Avian tuberculosis can be a signifi- ease. Necrotic enteritis of wild waterbirds, especially geese, cant risk for humans who are immunocompromised. Salmo- has been reported with increasing frequency during recent nellosis is a common, but seldom fatal, human infection that years. Clostridium perfringens has been associated with these can be acquired from infected wild birds. This section pro- deaths. vides individual chapters about only the more common and The frequency of wild bird mortality events and the vari- significant bacterial diseases of wild birds. Numerous other ety of infectious bacterial diseases causing that mortality has diseases afflict wild birds, some of which are identified in increased greatly during recent decades. Avian cholera has the chapter on Miscellaneous Bacterial Diseases included at become the most important infectious disease of waterbirds, the end of this section. but it did not appear in North American waterfowl or other Timely and accurate identification of causes of mortality waterbirds until 1944. Most of the geographic expansion and is needed to properly guide disease control operations. The increased frequency of outbreaks of avian cholera has oc- magnitude of losses and the rapidity with which those losses curred since 1970. Avian tuberculosis is a historic disease of can occur, as reflected in the chapters of this section, should captive birds, but it is relatively rare in North American wild be a strong incentive for those who are interested in the con- birds. The high prevalence of avian tuberculosis infection servation of wild species to seek disease diagnostic evalua- that has occurred since 1982 in a free-living foster-parented tions when sick and dead birds are encountered. In order to accurately determine what diseases are present, specimens need to be sent to diagnostic laboratories that are familiar Quote from: with the wide variety of possible diseases that may afflict wild birds. Those laboratories must also have the capability Garrett, L., 1994, The coming plague—Newly emerging diseases to isolate and identify the causative agents involved. Several in a world out of balance: Farrar, Straus, and Giroux, New sources of wildlife disease expertise that might be called upon York, N.Y., p. 411. when wildlife mortality occurs are identified within Appen- dix B . 74 Field Manual of Wildlife Diseases: Birds Chapter 7 Avian Cholera Synonyms 24–48 hours is more common. Susceptibility to infection and Fowl cholera, avian pasteurellosis, avian hemorrhagic the course of disease — whether or not it is acute or chronic septicemia — is dependent upon many factors including sex, age, ge- netic variation, immune status from previous exposure, con- Cause current infection, nutritional status, and other aspects of the Avian cholera is a contagious disease resulting from in- host; strain virulence and other aspects of the bacterium; and fection by the bacterium Pasteurella multocida. Several sub- dose and route of exposure. Infection in poultry generally species of bacteria have been proposed for P. multocida, and results when P. multocida enters the tissues of birds through at least 16 different P. multocida serotypes or characteristics the mucous membranes of the pharynx or upper air passages. of antigens in bacterial cells that differentiate bacterial vari- The bacterium can also enter through the membranes of the ants from each other have been recognized. The serotypes eye or through cuts and abrasions in the skin. It is assumed are further differentiated by other methods, including DNA that transmission is similar in wild birds. fingerprinting. These evaluations are useful for studying the Environmental contamination from diseased birds is a ecology of avian cholera (Fig. 7.1), because different sero- primary source for infection. High concentrations of types are generally found in poultry and free-ranging migra- P. multocida can be found for several weeks in waters where tory birds. These evaluations also show that different P. waterfowl and other birds die from this disease. Wetlands multocida serotypes are found in wild birds in the eastern and other areas can be contaminated by the body discharges United States than those that are found in the birds in the rest of diseased birds. As much as 15 milliliters of nasal discharge of the Nation (Fig. 7.2). containing massive numbers of P. multocida have been col- Acute P. multocida infections are common and they can lected from a single snow goose. Even greater amounts of result in bird deaths 6–12 hours after exposure, although bacteria enter the environment when scavengers open the 1 3 3, 4 Percentage of P. multocida serotypes in different types of wild birds. 3, 4, 12, 15 3, 12 1 3, 12, 15 4 Serotype 1 4, 7 All other serotypes SEROTYPE 4, 12 Waterbirds Landbirds 5 6 7 7, 12 1 Multiple numbers indicate 8 cross reactions to multiple antigens. 11 Scavengers Birds of prey 0 5 40 60 80 100 PERCENTAGE OF TOTAL INFECTED BIRDS (Total number of samples = 561) Figure 7.1 Distribution of Pasteurella multocida serotypes from 561 wild bird isolates from the United States. Avian Cholera 75 Figure 7.2 Distribution of Pas- FLYWAY1 SEROTYPE teurella multocida serotypes from Atlantic 1 561 wild birds isolated by waterfowl All others flyway. Mississippi 1 All others Central 1 All others 1Flyways are administrative units for the management of waterfowl that are Pacific 1 geographic representations of the primary All others migratory patterns of waterfowl. 0 20 40 60 80 100 PERCENTAGE OF TOTAL INFECTED BIRDS (BY FLYWAY) Route of transmission and field situation Comments Bird-to-bird contact Secretions from infected birds shedding P. multocida. Requires close contact, such as when individuals struggle over aquatic plants that they are feeding upon. Ingestion Probably most common