Lynn Hinckley

Paramoebiasis Associated with Mass Mortality of American Lobster Homarus americanus in Long Island Sound, USA

Abstract In the autumn of 1999, a mass mortality of American lobster Homarus americanus was reported by lobster fishermen from western Long Island Sound (LIS). At the conclusion of the 1999 season, dead lobsters were estimated at 11 million, resulting in a 90– 99% reduction of landings in western LIS and failure of the natural lobster fishery. Fishermen described moribund lobsters that were “limp,” interpreted clinically as paretic or flaccidly paralyzed. Necropsies were performed on dead or dying limp lobsters, and tissue samples were collected for histopathological, ultrastructural, microbiological, and toxicological analysis. Microbiological cultures of hemolymph and hepatopancreas failed to isolate a bacterium or group of bacteria in any significant frequency or pattern. Toxicological analyses of hepatopancreas and skeletal muscle did not identify significant amounts of trace elements, polycyclic aromatic hydrocarbons, polychlorinated biphenyl congeners, or pesticides. Microscopic analyses of hemocoel...

Disseminated phaeohyphomycosis in weedy seadragons (Phyllopteryx taeniolatus) and leafy seadragons (Phycodurus eques) caused by species of Exophiala, including a novel species

During the period from January 2002 to March 2007, infections by melanized fungi were identified with greater frequency in aquarium-maintained leafy seadragons (Phycodurus eques)and weedy seadragons (Phyllopteryx taeniolatus), pivotal species to the educational and environmental concerns of the aquarium industry and conservation groups. The objective of this study was to characterize the pathology and identify fungi associated with phaeohyphomycotic lesions in these species. Samples from 14 weedy and 6 leafy seadragons were received from 2 institutions and included fresh, frozen, and formalin-fixed tissues from necropsy and biopsy specimens. Fresh and frozen tissues were cultured for fungi on Sabouraud dextrose agar only or both Sabouraud dextrose agar and inhibitory mold agar with gentamicin and chloramphenicol at 30°C. Isolates were processed for morphologic identification and molecular sequence analysis of the internal transcribed spacer region and D1/D2 domains of the large subunit ribosomal RNA gene. Lesions were extensive and consisted of parenchymal and vascular necrosis with fungal invasion of gill (11/20), kidney (14/20), and other coelomic viscera with or without cutaneous ulceration (13/20). Exophiala sp. isolates were obtained from 4 weedy and 3 leafy seadragons and were identified to species level in 6 of 7 instances, namely Exophiala angulospora (1) and a novel species of Exophiala (5), based on nucleotide sequence comparisons and phylogenetic analyses. Disseminated phaeohyphomycosis represents an important pathologic condition of both weedy and leafy seadragons for which 2 species of Exophiala,1a novel species, have been isolated.

Fatal necrotising fasciitis and myositis in a cat associated with Streptococcus canis.

Necrotising fasciitis and necrotising myositis are rare but serious life threatening conditions reported mainly in human beings and dogs. Most cases to date have been caused by β-haemolytic streptococci of Lancefield groups A, B, C or G. Necrotising fasciitis has been reported only twice in cats and necrotising myositis has never been described. This paper describes a fatal case of necrotising fasciitis and myositis with pneumonia and septicaemia in a nine-year-old cat. The cat had been undergoing treatment for a suspected tear of the cranial cruciate ligament, but on the seventh day of treatment it suddenly deteriorated and died. On postmortem examination, there was an area of hair loss from its left hindlimb and discoloration of the underlying fascia and biceps femoris muscle. Severe necrotising fasciitis and myositis, with numerous intralesional Gram-positive coccoid bacteria, was diagnosed histologically. Other findings included necrotising pneumonia, pleuritis, focal encephalitis, myocarditis and nephritis. Culture of the affected tissues yielded a pure, heavy growth of Streptococcus canis.

Extraintestinal Pathogenic Escherichia coli-Induced Acute Necrotizing Pneumonia in Cats

Extraintestinal pathogenic Escherichia coli (ExPEC) are pathogens involved in several disease conditions, ranging from urinary tract infection to meningitis in humans and animals. They comprise epidemiologically and phylogenetically distinct strains, affecting most species and involving any organ or anatomical site. Here, we report fatal cases of necrotizing pneumonia in cats. Over a 1‐week period, 13 cats from an animal shelter in Stamford, Connecticut were presented for necropsy. All had a clinical history of acute respiratory disease. The gross and microscopic findings for all the cats were consistent. Escherichia coli was uniformly isolated from the lungs of all the tested cats. All the isolates were haemolytic, genetically related as determined by enterobacterial repetitive intergenic consensus PCR, and harboured genes encoding for cytotoxic necrotizing factor‐1 and fimbriae and adhesions that are characteristic of ExPEC, implying a point source clonal outbreak. As cats are common household pets, this report raises concerns regarding zoonotic potential (in either direction) for these ExPEC strains.

Mycoplasma sturni sp. nov., from the conjunctiva of a European starling (Sturnus vulgaris).

Strain UCMF(T) (T = type strain) was isolated from the conjunctiva of a European starling (Sturnus vulgaris) with conjunctivitis. Colonies grown on conventional mycoplasma agar possessed the typical fried-egg appearance observed with many mycoplasmal species. Electron micrographs of ultrathin sections of UCMF(T) revealed a pleomorphic cellular morphology; the cells ranged from spherical to elliptical or flask shaped. The cell size ranged from 0.3 to 0.5 microns. Strain UCMF(T) grows well in a variety of mycoplasma broth formulations at 25 degrees C, with rapid and heavy growth at 37 degrees C. No growth occurs at 42 degrees C. This organism ferments glucose but does not hydrolyze urea or arginine and has an absolute requirement for sterol from growth. Strain UCMF(T) does not hemagglutinate or hemadsorb chicken erythrocytes. The genome size is 870 kbp, and the guanine-plus-cytosine content is 31 mol%. Sequence analysis of the 16S rRNA gene demonstrated that this organism is unique and has not been described previously. Serological analysis confirmed that strain UCMF(T) is distinct from all previously identified Mycoplasma, Acholeplasma, Spiroplasma, Entomoplasma, and Mesoplasma species. This organism represents a new species, for which we propose the name Mycoplasma sturni. Strain UCMF (= ATCC 51945) is the type strain of M. sturni sp. nov.

Mycobacterium Marinum Dermatitis and Panniculitis with Chronic Pleuritis in a Captive White Whale (Delphinapterus Leucas) with Aortic Rupture

A 16-year-old female white whale, Delphinapterus leucas, died after nearly 18 months of chronic lymphopenia and pyogranulomatous dermatitis. Necropsy revealed rupture of the aorta with hemorrhage into the cranial mediastinum and between fascial planes of the ventral neck musculature. Multiple foci of ulcerative dermatitis and panniculitis were present across the thorax and abdomen and surrounded the genital folds. In addition, there was a chronic proliferative pleuritis with over 20 liters of histiocytic exudate in the thoracic cavity. Acid-fast bacteria consistent with Mycobacterium sp. were identified in sections of skin lesions and in cytospins of pleural exudate. Cultures of pleura and 1 skin lesion collected at necropsy yielded sparse growth of an acid-fast bacillus with colony characteristics and morphology consistent with Mycobacterium marinum. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis confirmed the presence of M. marinum DNA in samples of skin. This is the first documented occurrence of mycobacteriosis in a white whale and is a unique presentation of mycobacterial dermatitis and panniculitis with chronic pleuritis in a cetacean. The improved PCR-RFLP protocol utilized in this case unifies techniques from several protocols to differentiate between species of Nocardia and rapidly growing mycobacteria clinically relevant to aquatic animals.

Brucella sp. vertebral osteomyelitis with intercurrent fatal Staphylococcus aureus toxigenic enteritis in a bottlenose dolphin (Tursiops truncatus).

A previously beach-stranded, juvenile, male, bottlenose dolphin (Tursiops truncatus) was diagnosed with vertebral osteomyelitis of unknown etiology. Antemortem serological testing suggested past or current Brucella sp. infection; however, this could not be confirmed prior to death despite multiple isolation attempts from aspirates, blood, and biopsies. Systemic antibiotics were administered for over a year to control the suspected infection; however, the animal succumbed peracutely to infection by a highly pathogenic, enterotoxin-secreting Staphylococcus sp. Gross necropsy findings included a fistulous tract leading to locally extensive osteomyelitis of a coccygeal vertebra with sequestra and osteophytes from which a Brucella species was isolated. Histopathological examination of intestine revealed pseudomembranous enteritis with a uniform population of intraluminal Gram-positive cocci. Staphylococcus aureus was isolated in pure culture from the intestine and tested positive for the staphylococcal enterotoxin A gene by polymerase chain reaction analysis. Serum taken shortly before death had endotoxin and elevated antibody titers to staphylococcal enterotoxin A when compared to samples collected during a period of apparent good health 18 months earlier. The isolation of a pyrogenic toxin superantigen-producing staphylococcal isolate, clinical signs, and diagnostic findings in this animal resembled some of those noted in human toxic shock syndrome. The present case highlights the clinical challenges of treating chronic illnesses, complications of long-term antibiotic use, and promotion of pathogenic strains in cases of prolonged rehabilitation of marine mammals.

Effect of the earthworm (Eisenia foetida) on Salmonella enteritidis in horse manure

Abstract Salmonella enteritidis , an enteropathogen of humans, is a common isolated serotype of infected domestic animals and may be excreted in the feces of these animals. Because the manure from some infected animals may be applied to agricultural land as fertilizer, Salmonella may be introduced into the environment, possibly causing heavy contamination and posing a health hazard to human beings and other susceptible animals. Earthworm biotechnology has been suggested as a method for managing organic waste on soil. The present study was conducted to determine the effect of earthworms ( Eisenia foetida ) on Salmonella enteritidis inoculated to cultural dishes containing horse manure. Results indicated that 48 h after inoculation, the per cent decrease in the concentration of Salmonella was different ( P

Mycoplasmal Conjunctivitis in a European Starling

Bilateral conjunctivitis and episcleritis were identified in an adult European starling (Sturnus vulgaris). A novel mycoplasma species, Mycoplasma sturni, was isolated in pure culture from the conjunctiva of both eyes. The clinical presentation was similar to that of conjunctivitis in house finches (Carpodacus mexicanus) caused by Mycoplasma gallisepticum. However, the histologic lesions were distinct, by the presence of ulceration and epithelial hyperplasia and lacking a lymphoplasmacytic infiltration. Mycoplasma sturni ferments glucose, does not hemadsorb or hemagglutinate chicken erythrocytes, and grows rapidly at 37 C in comparison to other Mycoplasma spp. The role of M. sturni in conjunctivitis in other passerine species is presently unknown.

Erysipelothrix septicemia in a little blue penguin (Eudyptula minor).

On June 25, 2002, aquarium veterinarians treated a 5-year-old, male little blue penguin (Eudyptula minor) that was acutely recumbent and dull, with inappetence of 24-hour duration. The penguin died within 10 minutes of presentation despite emergency resuscitation efforts. Gross pathologic findings consisted of pulmonary congestion and intestinal hemorrhage. Histopathologic findings included necrosis of tips of intestinal villi, increased numbers of mononuclear cells in pulmonary interstitium and hepatic sinusoids, and gram-positive bacteria in systemic microvasculature. Transmission electron microscopic examination revealed short gram-positive bacilli located in lumina of glomerular capillaries and in cytoplasm of mononuclear phagocytic cells in the lung and liver. Erysipelothrix rhusiopathiae was recovered from the lung, liver, and intestine by bacteriologic culture. Amplicons from polymerase chain reaction (PCR) tests using Erysipelothrix genus–specific primers and total genomic DNA extracted from formalin-fixed, paraffin-embedded tissue sections of lung and intestine demonstrated 99% nucleotide sequence identity with 16S small-subunit ribosomal DNA of E. rhusiopathiae and E. tonsillarum. The source of infection was speculated to be fish in the diet; however, repeated attempts to detect Erysipelothrix spp. from the mucous layer of food fish using bacteriologic culture and PCR were unsuccessful. This is the first report of erysipelas in a captive aquatic bird. Details of the isolation of E. rhusiopathiae and the application of molecular testing to identify Erysipelothrix DNA in formalin-fixed, paraffin-embedded tissue sections are given.