Calculating changes in plasma lactate concentration following initial treatment in dogs with GDV may assist in determining prognosis and identifying patients that require more aggressive treatment.

The precarious status of desert (Gopherus agassizii) and gopher (Gopherus polyphemus) tortoises has resulted in research and conservation efforts that include health assessments as a substantial component of management decision-making. Therefore, it is critical that available diagnostic tests for diseases impacting these species undergo rigorous standardization and validation. Since 1992, analysis of exposure of tortoises to Mycoplasma agassizii, an etiological agent of upper respiratory tract disease, has relied on the detection of specific M. agassizii antibody by enzyme-linked immunosorbent assay (ELISA). We report here substantive refinements in the diagnostic assay and discuss the implications of its use in wildlife conservation and management. The ELISA has been refined to include more stringent quality control measures and has been converted to a clinically more meaningful titer reporting system, consistent with other diagnostic serologic tests. The ELISA results for 5,954 desert and gopher tortoises were plotted, and a subset of these serum samples (n ‫؍‬ 90) was used to determine end-point titers, to establish an optimum serum dilution for analyzing samples, and to construct a standard curve. The relationship between titer and A 405 was validated using 77 serum samples from known positive (n ‫؍‬ 48) and negative (n ‫؍‬ 29) control tortoises from prior transmission studies. The Youden index, J, and the optimal cut point, c, were estimated using ELISA results from the 77 control sera. Based on this evaluation, the refinement has substantially improved the performance of the assay (sensitivity of 0.98, specificity of 0.99, and J of 0.98), thus providing a clinically more reliable diagnostic test for this important infection of tortoises.

Mycoplasma alligatoris causes lethal invasive disease of alligators and caimans. A homolog of the nagH gene, encoding a hyaluronidase secreted by Clostridium perfringens, and a C. perfringens hyaluronidase nagI or nagK pseudogene were discovered in the M. alligatoris genome. The nagH gene was detected by PCR in the closest relative of M. alligatoris, Mycoplasma crocodyli, but not in 40 other species representing the Mycoplasma hominis, Mycoplasma pneumoniae, and Spiroplasma phylogenetic clusters. The hyaluronidase activity in the cellular fraction of M. alligatoris and M. crocodyli SP4 broth cultures was equivalent to 10 ؊16 U of Streptomyces hyalurolyticus hyaluronidase CFU ؊1 . Negligible activity was present in the cell-free supernatant fraction. No chondroitinase activity was detected. There is also a novel homolog of the nanI gene, which encodes a sialidase secreted by C. perfringens, in the M. alligatoris genome. The signature YRIP and SXDXGXTW motifs and catalytic residues of the clostridial sialidase are conserved in the mycoplasmal gene, but the leader sequence necessary for its secretion by C. perfringens is absent. The gene was not detected by PCR in any other mycoplasma. Potent cell-associated sialidase activity was present in M. alligatoris colonies on agar but not in the cell-free supernatants of broth cultures or in M. crocodyli. The presence of hyaluronidase and sialidase in M. alligatoris is consistent with the rapid invasiveness and necrotizing effects of this organism, and the lack of sialidase in M. crocodyli is consistent with its comparatively attenuated virulence. This genetic and biochemical evidence suggests that the spreading factors hyaluronidase and sialidase, a combination unprecedented in mycoplasmas, are the basis of the virulence of M. alligatoris.Mycoplasma alligatoris causes a lethal invasive disease in adult alligators (Alligator mississippiensis) and closely related caimans (Caiman latirostris). The pathology observed as early as 1 week after infection by instillation via the glottis includes necrotizing pneumonia, severe pericarditis, necrotizing myocarditis, lymphocytic interstitial nephritis, lymphocytic periportal hepatitis, splenic hyperplasia, pyogranulomatous meningitis, and necrotizing synovitis (9,10,11,13,18,33). Hatchling alligators also rapidly developed disseminated M. alligatoris mycoplasmosis after intratracheal instillation, and the lesions are similar to those of adults and include acute multifocal brainstem hemorrhage (35). Mycoplasma crocodyli (23), the closest known relative of M. alligatoris (98% 16S rRNA gene similarity [9]), causes a similar necrotizing synovitis and occasionally subacute pneumonia in Nile crocodiles (Crocodylus niloticus) (27,28). The severity of the lesions correlates with the numbers of M. alligatoris cells in affected tissues, suggesting that a spreading factor(s) contributes to the virulence. The extracellular matrix (ECM)-degrading enzymes that act as bacterial spreading factors include hyaluronidases, sialidases, and mucinases (26...

An epidemic of pneumonia with fibrinous polyserositis and multifocal arthritis emerged in captive American alligators (Alligator mississippiensis) in Florida, United States, in 1995. Mycoplasma alligatoris sp. nov. was cultured from multiple organs, peripheral blood, synovial fluid, and cerebrospinal fluid of affected alligators. In a subsequent experimental inoculation study, the Henle-Koch-Evans postulates were fulfilled for M. alligatoris as the etiological agent of fatal mycoplasmosis of alligators. That finding was remarkable because mycoplasmal disease is rarely fatal in animals. An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies produced by alligators in response to M. alligatoris exposure was developed by using plasma obtained from naturally infected alligators during the original epidemic. The assay was validated by using plasma obtained during an experimental dose-response study and applied to analyze plasma obtained from captive and wild crocodilian species. The ELISA reliably detected alligator seroconversion (P < 0.05) beginning 6 weeks after inoculation. The ELISA also detected seroconversion (P < 0.05) in the relatively closely related broad-nosed caiman Caiman latirostris and the relatively distantly related Siamese crocodile Crocodylus siamensis following experimental inoculation with M. alligatoris. The ELISA may be used to monitor exposure to the lethal pathogen M. alligatoris among captive, repatriated, and wild crocodilian species.An epidemic of mycoplasmosis emerged in a collection of American alligators (Alligator mississippiensis) in Florida in 1995 (4, 8). Thirty-three 200-to 300-kg adult male alligators died, and 13 moribund alligators were euthanatized within 1 month of the index case. Lesions observed at necropsy ranged from mild interstitial and peribronchiolar pneumonia to fibronecrotic pneumonia. Extrapulmonary complications included pericarditis, myocarditis, and multifocal arthritis. Mycoplasma alligatoris proposed sp. nov. was isolated from multiple tissues, blood, synovial fluid, and cerebrospinal fluid of affected alligators. In a pilot experimental inoculation study (5, 6), healthy alligators were inoculated with M. alligatoris strain A21JP2 T (ATCC 700619) to reproduce the disease and fulfill the HenleKoch-Evans postulates (11) for M. alligatoris as the etiological agent of synovitis, polyserositis, and pneumonia of alligators. The results were remarkable because, except for bovine and caprine pleuropneumonia, mycoplasmal disease is rarely fatal in animals.The origin of the 1995 epidemic remains unknown, but the disease may emerge under conditions of captivity. Crocodilians are frequently sold or traded among collections, exhibits, zoos, and ranches. Many collections include multiple species of crocodilians. Some crocodilians from commercial ranches are repatriated after "head-starting" hatchlings from eggs collected in the wild, a potential vector for catastrophic infection of wild populations if lethal disease emerges in captivity. A validated ser...

Mycoplasmas were isolated from multiple tissues of diseased American alligators (Alligator mississippiensis). This paper presents biochemical, serological and molecular genetic characterizations of a lethal pathogen of alligators for which the name Mycoplasma alligatoris sp. nov. is proposed. The type strain is A21JP2 T (ATCC 700619 T ).

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Mycoplasma alligatoris causes acute lethal infection of alligators (Alligator mississippiensis). The objective of this study was to assess the current seroprevalence of M. alligatoris among free-ranging, juvenile and subadult alligators in Florida. Thirty-two of 592 (5.4%) plasma samples from alligators at 12 of 20 sites (60%) in April and October 2003 were tested seropositive (titer 1: > or = 32) by enzyme-linked immunosorbent assay for anti-M. alligatoris antibodies. These results show that alligators throughout Florida have a recent history of exposure to M. alligatoris and suggest that contact with free-ranging alligators may constitute a risk of lethal infection of susceptible crocodilians.