Characterization of Arcanobacterium abortisuis by phenotypic properties and by sequencing the 16S-23S rDNA intergenic spacer region

The present study was designed to characterize phenotypically and genotypically nine Arcanobacterium abortisuis strains collected from specimen of pigs in a period of nine years. All nine A. abortisuis strains and A. abortisuis reference strain DSM 19515 displayed a synergistic hemolytic reaction with Staphylococcus aureus β-hemolysin, Rhodococcus equi, and Arcanobacterium haemolyticum indicator strains and showed the typical biochemical properties of this species. The species identity could be confirmed by identification and sequencing of the 16S-23S rDNA intergenic spacer region (ISR), which appeared to be a useful target for genotypic characterization of this bacterial species. The A. abortisuis strains of the present study were isolated from specimen of pigs together with various other bacterial species indicating that the pathogenic importance of this newly described species remains to be elucidated.     

Isolation of Arcanobacterium hippocoleae from a case of placentitis and stillbirth in a mare

Based on the scarcity of reports in veterinary medicine literature, it appears that Arcanobacterium spp. are rarely isolated from horses. Recently, a single isolate from vaginal discharge in a mare was characterized as a new species, Arcanobacterium hippocoleae. The present report describes a case of necrosuppurative placentitis and stillbirth in an American Quarterhorse mare. Numerous colonies of irregular, Gram-positive, rod-shaped bacteria were observed by histological examination within fibrin lattice associated with placental lesions. Arcanobacterium hippocoleae was isolated in large numbers from the placenta, lung, and stomach contents. To the authors' knowledge, this is the first report of placentitis associated with Arcanobacterium spp. in a horse and the third reported isolation of A. hippocoleae from a horse.     

Hemorrhagic necrotizing splenitis in a slaughter pig infected with Arcanobacterium species

A 6-month-old barrow presented with lethargy, inappetence and dysstasia. At necropsy, multiple coalescing hemorrhagic foci were detected in the margins of the spleen. Gram-positive bacilli were isolated from the spleen, kidney, muscle and liver. Comparative 16S rDNA gene sequencing analysis of the isolates (TO16177) revealed that they would be the same species of unpublished Arcanobacterium species strain HJ57-14E (accession no. gi 18873551) (99.7% similarity based on a comparison of 675 bp). Histologic examination of the splenic tissue sections revealed extensive necrosis and inflammation, and gram-positive bacilli were discernible. Multifocal necrosis was also detected in the liver. Immunohistochemically, the isolates were cross-reacted with polyclonal antibodies against Arcanobacterium pyogenes and Actinomyces naeslundii, and the reaction was strong for the latter. Similar reactions were found in the suppurative lesions of the tonsil, and occasionally in the spleen and lymph nodes. The present results indicate that the unpublished Arcanobacterium species induced multiple organ failure accompanied by acute hemorrhagic necrotizing splenitis in this growing-finishing pig.     

Observations on abortions in cattle: a comparison of pathological, microbiological and immunological findings in aborted foetuses and foetuses collected at abattoirs.

Fifty nonaborted and 50 aborted bovine foetuses were examined utilizing histology, immunoelectrophoresis, bacteriology and the fluorescent antibody technique. Lesions were observed in 12 of the nonaborted foesuses and in four of these immunoglobulins were demonstrated. In addition, two of the nonaborted foetuses had immunoglobulins in the absence of observed lesions. Lesions were observed in 48 of the aborted foetuses and immunoglobulins were detected in 22 of these. An etiological diagnosis was arrived at in 24 of the 50 aborted foetuses. The tissues most frequently observed to have lesions of diagnostic significance were eyelid, intestine, liver, lung and placenta. Intestinal lesions were observed in several foetuses in association with a variety of agents including infectious bovine rhinotracheitis. Foetuses diagnosed as aborting because of mycotic infection consistently displayed lesions in their eyelids. The value of taking eyelid sections in cases of suspected mycotic abortions, the significance of foetal intestinal lesions, the evaluation of abomasal aspirates and the diagnostic importance of immunoglobulin determinations in aborted foetuses are discussed.     

Presumptive Toxoplasma gondii abortion in a sheep

A primiparous ewe aborted in mid-gestation. Toxoplasma gondii was suspected as the cause of abortion and a presumptive diagnosis of T. gondii abortion was based on histological lesions of the placenta.     

Staphylococcus-associated abortions in ewes with long-term central venous catheterization

Forty-two ewes had an intravenous catheter sewn in place in a prepared area over the jugular vein and beginning at 60 days of gestation received an infusion 3 times daily. The infusion consisted of sterile saline or sterile saline containing arginine. Twenty-six ewes in both control and treatment groups aborted between 81 days of gestation and term. Fetuses from 16 ewes that aborted were examined. Most were autolyzed or had early mummification. Macroscopic placentitis and noncollapsing lungs were noted. Large numbers of coagulase-positive Staphylococcus were isolated from fetal abomasal content, lungs, brains, or placentas. Histologically, suppurative placentitis with necrosis and pulmonary aspiration of meconium and amniotic debris often with suppurative bronchopneumonia were observed in abortuses. Four ewes euthanized and examined after abortion had suppurative endometritis. Three ewes had severe, chronic, jugular thrombophlebitis from which coagulase-positive Staphylococcus was isolated. The fourth ewe had mild phlebitis, and Staphylococcus aureus was isolated from both the catheter and the blood. Catheter-associated staphylococcal abortion was diagnosed.     

Placental lesions caused by pseudorabies virus in pregnant sows

Pathologic and viral investigations were done on 13 fetal placentas and 23 aborted fetuses associated with naturally occurring pseudorabies in swine. Of the 13 fetal placentas examined, 7 (53.8%) had various degrees of necrotizing placentitis. The lesions were characterized by coagulative necrosis of the chorionic fossae and by intranuclear inclusions in degenerating trophoblasts and occasionally in mesenchymal cells. In addition, a mild inflammatory cell reaction was observed in the mesenchyma. Numerous viral particles, ultrastructurally indistinguishable from herpesvirus, were observed by electron microscopy in the affected chorionic membrane. Large aggregates of herpesvirus virions were demonstrated in the nucleus and cytoplasm of degenerated trophoblasts and mesenchymal cells. Of the 23 aborted fetuses examined, 22 (95.6%) had typical coagulative necrosis in the liver, spleen, adrenal glands, and visceral lymph nodes. Inclusions similar to those in the chorionic placenta were observed in the parenchymal cells of those organs, on the margins of necrotic areas. Pseudorabies virus was isolated from various organs of the aborted fetuses, but virus isolation from the placentas was not attempted. In a survey of 52 affected sows, sera from 49 (94.2%) neutralized the isolated virus. The findings indicated that the placental lesions caused by the virus were primary. The study also indicated the merit of routine examination of aborted fetal placentas and fetuses for diagnosis of pseudorabies.     

Experimental infection and abortion of pregnant guinea pigs with a unique spirillum-like bacterium isolated from aborted ovine fetuses

Study was made of the pathogenicity of a spirillum-like, anaerobic, gram-negative bacterium, originally isolated from aborted lambs, for pregnant guinea pigs. Reproducible conditions for propagation and preservation of the bacterium were determined as requisite for the preparation of cultures for animal inoculation. A preliminary experiment was done with 10 pregnant guinea pigs to test for an infective dose of organisms that would produce abortion. High-passage cultures (n = 50) were used to inoculate these guinea pigs intraperitoneally. Six of 10 guinea pigs aborted, and the organism was cultured from fetal tissues of 5 guinea pigs. Isolates from 3 of the 6 guinea pigs were propagated through 4 passages on blood agar and used to infect 3 groups, each of 5 guinea pigs. A 4th group of 5 guinea pigs was inoculated with the original culture. Three of 5 animals in the first 3 groups, which had been given the low-passage cultures from the preliminary trial, and 2 of 5 guinea pigs in the 4th group, which had been given the original culture, aborted. Antibody against the spirillum was detected in 19 of 30 inoculated guinea pigs. The major microscopic lesions were acute suppurative placentitis and splenitis. This bacterium retained pathogenic properties sufficient to cause infection, abortion, and microscopic lesions in two-thirds of the guinea pigs, in spite of high in vitro passage. The organism has unique ultrastructures, and its genus and species are yet to be determined.     

Diagnostic evidence of Staphylococcus warneri as a possible cause of bovine abortion.

Following a routine necropsy of a bovine fetus aborted at 5 months of gestation, placenta, fetal tissue samples, and stomach contents were subjected to a number of laboratory tests. Staphylococcus warneri was isolated in pure culture from the lung, liver, and stomach contents, whereas the placenta yielded S. warneri and a number of contaminants. Gross evaluation of agar plates showed predominant colonies to be morphologically consistent with those of S. warneri and the identity of the agent was further confirmed on a Trek Diagnostic Systems Sensititre, gram-positive identification (GPID) plate. Microscopic evaluation of fetal tissue sections showed extensive necrotizing lesions of the tongue, lung, and placenta in which there were numerous coccoid shaped gram-positive bacteria with morphology consistent with Staphylococcus spp. These results provide strong diagnostic evidence of S. warneri as a possible cause of bovine abortion and suggest there should be further investigations into the abortivirulence of this agent.     

Identification of Arcanobacterium (Trueperella) abortisuis, a novel species of veterinary importance, by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)

In the present study A. (T.) abortisuis isolated from pigs and bovines could be reliably identified by determination of phenotypic properties, genotypically by polymerase chain reaction with the help of A. (T.) abortisuis 16s-23S rDNA intergenic spacer region specific oligonucleotide primer and by Matrix-Assisted Laser Desorption Ionization-Time Of Flight mass spectrometry (MALDI-TOF MS). The latter appeared to be a promising tool for fast and cost effective identification of this species and might help to elucidate the role A. (T.) abortisuis plays in infections of pigs, bovines, possibly other animals or humans.     

Toxoplasma gondii diagnosis in ovine aborted fetuses and stillborns in the State of Pernambuco, Brazil

The aim of this research was to study the contribution of Toxoplasma gondii to reproductive failure using nested PCR and histopathological examination of fetuses, stillborns and placentas. We examined 245 organs of fetuses and 28 placentas from 35 abortions and stillborns from naturally occurring miscarriages in sheep in the State of Pernambuco, Brazil. At necropsy, fragments of brain, cerebellum, medulla, lung, heart, spleen, liver and placenta were taken for nested PCR and histopathological tests. Pathological examination revealed macroscopic lesions, suggesting T. gondii infection in 5/35 (14.3%) of the placentas. The histopathological examination revealed no lesions characteristic of toxoplasmosis in the organs investigated. In the five placentas, lesions consistent with toxoplasmosis were observed as an inflammatory non-suppurative infiltrate, along with multiple necrosis and mineralization. Nested PCR showed three aborted fetuses and two stillborns (14.3%) to test positive for T. gondii, with DNA amplification in all organs and the placenta, especially the heart and the placenta, which are the tissues of choice. This study substantiates the theory that T. gondii is involved in miscarriages and stillbirths and in the placentas of naturally infected sheep in Brazil. Such findings have not previously been described in the national literature.     

Systemic Mycobacteriosis in an Aborted Thoroughbred Fetus in Japan

A male Thoroughbred fetus was aborted on day 251 of pregnancy. Gross and histological examinations detected systemic granulomatous lesions in many superficial and visceral lymph nodes and organs including the liver, tonsils, lungs, thymus, spleen, right thyroid gland and gastrointestinal tract, and suppurative placentitis, pyogranulomatous amnionitis and intralesional acid-fast bacilli were also detected. An examination of the DNA base sequence of the β subunit of RNA polymerase demonstrated that Mycobacterium avium strain 104 had infected several organs. To the best of our knowledge, this is the first report of equine fetal mycobacterial infection in Japan.     

Disease in a dairy herd associated with the introduction and spread of bovine virus diarrhoea virus

In January 1982 an outbreak of diarrhoea among adult dairy cows in a closed herd of approximately 200 milking animals was shown to be caused by the introduction of bovine virus diarrhoea virus (BVDV). Affected animals showed a significant reduction in milk yield. One animal died and four were culled. Eight cows aborted and one weak calf was born. Of 121 calves born that year, 26 died, mostly from pneumonia, but five aged from three weeks to five months had enteric lesions of mucosal disease. Subsequent investigations of the whole herd in 1983 and 1984 showed that virus spread among the adults was slow and that BVDV continued to make a major contribution to calf losses. Again the greatest cause of loss was suppurative or fibrinous pneumonia. Overall, BVDV was isolated from 36 animals. Isolation of virus from a wide range of tissues of individual animals confirmed that they were viraemic at death. Viruses from calves dying of pneumonia and from aborted fetuses were non-cytopathic in tissue culture. Isolates showing varying degrees of cytopathogenicity were obtained only from tissues of one calf with a congenital neurological defect and the seven animals with enteric lesions consistent with a diagnosis of mucosal disease. Blood from all 89 BVDV antibody-free animals older than three months was tested for the presence of BVDV. Altogether, 12 calves were identified as persistently viraemic and all were apparently healthy when bled. Only two matured normally, four grew poorly and six died.(ABSTRACT TRUNCATED AT 250 WORDS)     

Demonstration of Chlamydia from an equine abortion

The isolation and identification of a chlamydial agent from an equine fetus is reported. The fetus was aborted by a mare with respiratory disease and fever in the 9th month of pregnancy. The serum of the mare was investigated by the compliment fixation test. Specific antibodies were detected for chlamydial antigen in a titer of > 1:40 and for equine herpes virus 1 antigen in a titer of 1:32. Pathological lesions were not found in the organs of the fetus. Chlamydiae were detected in the placenta by ELISA and subsequently isolated by cell culture. Using PCR technique the agent was identified as Chlamydophila psittaci.     

Ovine abortion and stillbirth due to purulent placentitis caused by Yersinia pseudotuberculosis

Yersinia pseudotuberculosis was isolated from an aborted placenta and stillborn lamb from a sheep flock having multiple abortions. Given intravenously, it caused elevated body temperatures and purulent placentitis in eight of nine ewes. Two ewes died following infection at 2.5 months of gestation. Two ewes infected at 3.5 months gestation aborted; three infected at four months gave birth to weak, premature, or moribund lambs. One ewe infected at 4.5 months gave birth to a healthy lamb. One lamb which died minutes after birth had focal necrotizing hepatitis, a lesion observed in a stillborn lamb during the original disease outbreak. Y. pseudotuberculosis was reisolated from endometrial, placental, and fetal lesions of experimentally infected animals.     

Encephalitozoon cuniculi placentitis and abortion in a quarterhorse mare.

Encephalitozoon cuniculi is a microsporidial parasite, which has rarely been reported to cause placentitis in animals. A late-term aborted fetus and placenta from a Quarterhorse were presented to the Livestock Disease Diagnostic Center, University of Kentucky, for diagnostic examination. There was a necrotizing placentitis, with distension of many chorionic epithelial cells by intracytoplasmic vacuoles containing 1-2-microm-diameter, elongated, gram-positive organisms. The organisms were identified as E. cuniculi by electron microscopy and by polymerase chain reaction using primers to microsporidial ribosomal DNA. Joints of the fetus were swollen, with gross and microscopic lesions of synovitis; however, E. cuniculi DNA was not detected.     

Bovine abortion and necrotic placentitis by Aspergillus terreus

A 31-month-old Japanese Black cow (Bos taurus) aborted at 5 months of gestation with no clinical symptoms. Histopathological examination of the placenta and fetus revealed severe necrotic placentitis associated with numerous irregular degenerative fungi and inflammatory cells. Regular filamentous fungi were also detected, without inflammatory response in the fetal digestive and respiratory organs. Both fungi had aleurioconidia and septa in the placenta and fetal organs and immunohistochemically stained with antibodies against Aspergillus spp. Aspergillus terreus was isolated from the fetal lung and abomasal contents as confirmed using mycological and molecular methods. This is the first immunohistochemical, morphological, and molecular identification of A. terreus in bovine placenta and aborted fetuses.     

Mycobacterium fortuitum abortion in a sow

Two aborted Chester White pig fetuses were presented to a veterinary diagnostic laboratory in Illinois. Postmortem examination identified no gross abnormalities. Histologic evaluation revealed multifocal necrosis of chorionic epithelial cells, coalescing areas of mineralization in the placenta, and focal accumulations of viable and degenerate neutrophils in the lung. Intra- and extracellular acid-fast bacilli were identified in the lesions in both the placenta and lungs. Bacterial culture of stomach contents yielded heavy growth of Mycobacterium fortuitum, a rapidly growing nontuberculous mycobacterium (NTM), which was further confirmed through whole-genome sequencing. NTM are opportunistic pathogens commonly found in the soil and in contaminated water supplies. In animals, M. fortuitum is typically introduced through cutaneous wounds leading to infections limited to the skin, with systemic infection being uncommon. To our knowledge, abortion caused by M. fortuitum has not been reported previously.     

Two cases of equine abortion caused by Rhodococcus equi

Rhodococcus equi was isolated from lung, liver, spleen, and stomach content of two aborted equine fetuses of 7 and 8 months gestation from two different farms. Lesions included diffuse pyogranulomatous pneumonia with numerous Gram-positive coccobacilli within the cytoplasm of macrophages, multinucleated Langhans giant cells and neutrophils, and enhanced extramedullary hematopoiesis with megakaryocytosis within the liver and spleen. Detection of R. equi was made by bacteriology and immunohistochemistry for R. equi and VapA, the virulence factor of R. equi. R. equi and VapA were identified within the lungs of both fetuses, and its distribution correlated with lesions. Fetal lesions were similar to those observed in foals. We speculate that the fetuses contracted infection from the placenta by normal breathing movements or by swallowing of the amniotic fluid contaminated with R. equi.