Abstract
As noted in its introduction, this is the first English-language text since 1975 to be devoted to clostridial diseases of animals. At 336 pages and published in May 2016, the book is short and topical with 5 sections on various aspects of clostridia. These provide an overview of pathogenic clostridia, the toxins produced, and gastrointestinal, histotoxic, and neurotoxic clostridial diseases. The 27 chapters are written by 32 authors from North and South America, Europe, and Australia. Of 4 editors, 3—Uzal, Songer, and Prescott—are well known in veterinary diagnostic circles. The fourth, Popoff, spent a lifetime characterizing the biology of toxins of multiple species that afflict people and animals.
The end product is a balanced mix of expertise in diagnostic bacteriology and pathology, emphasizing molecular methods and diagnostic lesions. The book is well illustrated. Care was taken to generate good quality color images of representative gross and microscopic abnormalities. Mercifully, we are spared postage stamp pathology. Additional color drawings illustrate the structure and action of selected clostridial toxins.
Most disease chapters have sections on etiology, epidemiology, pathogenesis, clinical signs, typical lesions, and approaches to diagnosis, prevention, and treatment. Of interest to diagnosticians are statements about when an unequivocal diagnosis or its approximation can be made, and the value of preventive measures, including vaccination. Some authors are more forthright than others about interpreting the detection of specific toxin genes, and whether it is reasonable to infer toxin(s) secreted within the host. The chapter on necrotic enteritis in poultry by Cooper and Songer sets the standard. It is helpful to find statements that no marketed vaccine matches the efficacy of antimicrobial growth promoters now banned in the European Union, and that presumptive laboratory diagnosis requires a marriage of typical gross and microscopic lesions combined with detecting netB and possibly tpeL-positive Clostridium perfringens from damaged gut.
There are several particularly strong chapters. One addresses the vexed complex of abomasal bloat-clostridial abomasitis, the associated organisms of which ignore standard texts. It reviews abomasitis where Clostridium septicum is absent and in which other clostridial agents are detected, with or without Sarcina spp. The chapter on botulism, by 3 French authors, is excellent. Its diagnostic section discusses alternatives to the mouse bioassay, such as ELISA detection of botulinum neurotoxins, enzymatic methods based on BoNT cleavage of synthetic peptides, and PCR for bont genes encoding, among others, neurotoxin-encoding sequences. Several chapters are devoted to clostridial diseases that can be challenging to confirm. These include necrotic enteritis in mammals, where only C. perfringens A is detected, particularly CPE- and NetF-associated strains, and Clostridium difficile in pigs, horses, and laboratory species.
There are minor irritations. The index is parsimonious at 4 pages, and some common diagnostic terms used in the text are unlisted (e.g., “enterotoxemia”; “struck”). Each chapter has a separate bibliography, yet supporting references are not given for specific statements. As is standard for American texts, landmark papers from the past are ignored—poor William Faulkner wrote in vain. There is chapter-to-chapter variation in the number of references; the tetanus chapter has 8, whereas botulism has >150. Those aside, it is unusual to find a contemporary text that underscores the pertinence of finding suggestive lesions to bolster a tentative molecular diagnosis. The text benchmarks where we are now in diagnosing clostridial disease in animals, including pitfalls for the unwary. It is a reasonable value at $150 for a hardbound copy.