Evidence for vertical transmission of Mycoplasma haemocanis,but not Ehrlichia ewingii,in a dog

A 2‐year‐old female intact pregnant Beagle was evaluated after the owner surrendered her to a shelter. Prepartum and 2 months postpartum at the time of routine spay, the dam was whole‐blood polymerase chain reaction (PCR) positive for Ehrlichia ewingii. She was also whole‐blood PCR positive for Mycoplasma haemocanis prepartum and continuously for 5 months thereafter. The dam delivered 5 healthy puppies, 1 of which was whole‐blood PCR positive for M. haemocanis. All 5 puppies had antibodies against Ehrlichia spp. at 1 month of age but not thereafter, and all puppies were Ehrlichia spp. PCR negative for 5 months of follow‐up. Therefore, this study supports a potential role for vertical transmission in the maintenance of M. haemocanis in dogs as reservoir hosts. In contrast, in this case there was no evidence that E. ewingii was transmitted transplacentally or during the perinatal period.     

In vivo growth and genomic characterization of rickettsia‐like organisms isolated from farmed Chinook salmon (Oncorhynchus tshawytscha) in New Zealand

A rickettsia‐like organism, designated NZ‐RLO2, was isolated from Chinook salmon (Oncorhynchus tshawytscha) farmed in the South Island, New Zealand. In vivo growth showed NZ‐RLO2 was able to grow in CHSE‐214, EPC, BHK‐21, C6/36 and Sf21 cell lines, while Piscirickettsia salmonis LF‐89^T grew in all but BHK‐21 and Sf21. NZ‐RLO2 grew optimally in EPC at 15°C, CHSE‐214 and EPC at 18°C. The growth of LF‐89 ^T was optimal at 15°C, 18°C and 22°C in CHSE‐24, but appeared less efficient in EPC cells at all temperatures. Pan‐genome comparison of predicted proteomes shows that available Chilean strains of P. salmonis grouped into two clusters (p‐value = 94%). NZ‐RLO2 was genetically different from previously described NZ‐RLO1, and both strains grouped separately from the Chilean strains in one of the two clusters (p‐value = 88%), but were closely related to each other. TaqMan and Sybr Green real‐time PCR targeting RNA polymerase (rpoB) and DNA primase (dnaG), respectively, were developed to detect NZ‐RLO2. This study indicates that the New Zealand strains showed a closer genetic relationship to one of the Chilean P. salmonis clusters; however, more Piscirickettsia genomes from wider geographical regions and diverse hosts are needed to better understand the classification within this genus.     

“红肉病”文蛤中寄生类立克次体的超微结构与细胞病理学

报道了患“红肉病”文蛤的消化盲囊上皮中所发现的类立克次体以及所引起的受感染细胞的病理学变化。该病原包涵体呈球形或椭球形,有强嗜碱性和嗜酸性两种,电镜下观察到上皮细胞内充满了大量的类立克次体,其形态结构及大小表现了极大的多样性,受感染的细胞具有明显的病理学变化,内质网膨大为潴泡状,核糖体脱落;线粒体溶解或固缩,核膜肿胀,染色质固缩并出现液泡结构,高度感染时,细胞核与大部分的细胞器消失,在上皮细胞中,观察到类立克次体以二分裂和出芽方式进行繁殖。     

患颤抖病中华绒螯蟹体内类立克次体侵染的光镜和电镜观察

对江苏和安徽地区患颤抖病的中华绒螯蟹（Eriocheir sinensis)各器官和组织进行光镜和电镜观察。结果表明，类立克次体（Richettsia-like Organisms,RLOs)广泛寄生于病蟹各器官和组织中。它们特异性地寄生于病蟹各器官的肌肉和结缔组织以及血细胞中，血淋巴中的小颗粒细胞是类立克次体的主要繁殖场所和传播载体。类立克次体对病蟹机体的结缔组织的广泛侵入，以及对胸神经节及神经与肌肉的接头-运动终板的侵染正是颤抖病症状（不食、肌无力、肢体阵发性颤抖）的病理结构基础。本研究旨在探讨RLOs与中华绒螯蟹颤抖病的关系，从而为建立有效的防治措施奠定理论基础。     

ORCHITIS IN TWO DOGS WITH ROCKY MOUNTAIN SPOTTED FEVER

Two dogs with testicular swelling were sonographically diagnosed with orchitis and were subsequently diagnosed with Rocky Mountain spotted fever (RMSF). Use of both gray scale and color Doppler sonography allowed for differentiation of orchitis from neoplasia and torsion. While only experimentally induced RMSF is reported to cause orchitis in dogs, it should be considered in any dog with vascular insult to the testes, especially when other signs of systemic illness are involved.     

Transmission of Cowdria ruminantium by Amblyomma gemma from Infected African Buffalo (Syncerus caffer) and Eland (Taurotragus oryx) to sheep

Two African buffalo (Syncerus caffer), an eland (Taurotragus oryx) and a waterbuck (Kobus defassa) were intravenously inoculated with Cowdria ruminantium (Kiswani). Amblyomma gemma nymphs were fed on the animals at 3 weekly intervals. Jugular blood was also collected at 3 weekly intervals and inoculated into sheep. Nymphal ticks that fed on one buffalo on days 16 and 37 and on the other buffalo on day 58 after infection transmitted the disease as adults to sheep. Nymphs that were applied to the eland 16 days after infection also transmitted the disease to sheep. No nymphs that had fed on the waterbuck transmitted the disease. This is the first report of transmission of heartwater by Amblyomma gemma from infected wild ruminant species to a susceptible domestic ruminant species.     

Mixed Ehrlichia canis, Hepatozoon canis, and presumptive Anaplasma phagocytophilum infection in a dog

A 5-month-old, female, mongrel dog was admitted to the Clinic of Companion Animal Medicine, Aristotle University of Thessaloniki, Greece, with depression, anorexia, fever, peripheral lymphadenopathy, splenomegaly, oculonasal discharge, nonregenerative anemia, and mild thrombocytopenia. Cytology of Giemsa-stained buffy coat, bone marrow, and lymph node aspiration smears revealed numerous morulae in mononuclear leukocytes and in neutrophils, and Hepatozoon canis gamonts in neutrophils. The dog was seropositive to Ehrlichia canis (immunofluorescence assay [IFA]) and Hepatozoon canis (ELISA) but not to Anaplasma phagocytophilum (IFA). A nested polymerase chain reaction performed on bone marrow aspirates was positive for E canis. This method was not applied for the detection of A phagocytophilum. Treatment with doxycycline and imidocarb dipropionate resulted in both clinical and parasitologic cure. This is the first reported case of a mixed infection with E canis, H canis, and presumptive A phagocytophilum. The findings emphasize the value of cytology in offering a quick and inexpensive diagnosis in mixed tick-borne infections of dogs.     

Identifying the causal agent of necrotizing hepatopancreatitis in shrimp: Multilocus sequence analysis approach

The causal agent of the necrotizing hepatopancreatitis (NHP) disease in penaeid shrimp and other crustaceans was studied by sequencing its genome and locating particular biomarker genes that could contribute to a better taxonomic classification. Hepatopancreas of shrimp with clear signs of NHP was used as infective inoculum. The disease was reproduced and the causal agent was isolated by Percoll gradient. Genomic DNA was extracted, purified, submitted to high throughput sequencing and de novo assembled. Thereafter, strategies aimed to improve the taxonomic classification of the pathogen were used. A phylogenetic classification by multilocus sequence analysis (MLSA) was performed using the complete gene sequences of 16S rRNA, gyrase subunit alpha (gyrA), gyrase subunit beta (gyrB), RNA polymerase subunit beta (rpoB), ATP synthase subunit beta (atpD) and recombinase subunit alpha (recA). Phylogenetic analysis confirmed with a greater degree of confidence that the causal agent of NHP in shrimp belongs to the Holosporaceae family, with similarity to some species considered as pathogens of other arthropods.