Anaplasma Phagocytophilum intragranulocytic morulae in aborting sheep: a herd case in Sicily

An Accessible Diagnostic Toolbox to Detect Bacterial Causes of Ovine and Caprine Abortion

Results of laboratory investigations of ovine and caprine cases of abortion in the lambing season 2015–2016 were analyzed, using pathology records of submissions to Royal GD (Deventer, the Netherlands) from January until and including April 2016, in comparison with the results of two accessible alternative techniques for sampling aborted lambs and kids, swabbing the fetal oropharynx and puncture of the fetal lung. Chlamydia abortus was the main cause of abortion in sheep as well as in goats. Other causes of abortion were Campylobacter spp., Listeria spp., Escherichia coli, and Yersinia enterocolitica. Ovine pathological submissions resulted more often in detecting an infectious agent compared to caprine submissions. For the three main bacterial causes of abortion, Campylobacter spp., Listeria spp., and Chlamydia spp., compared to results of the pathological examination, oropharynx mucus, and fetal lung puncture samples showed an observed agreement of 0.87 and 0.89, an expected agreement of 0.579 and 0.584, and a kappa value of 0.691 and 0.737 (95% CI: 0.561–0.82 and 0.614–0.859), respectively. The agreement between the results of the pathological examination and both fetal lung puncture and oropharynx mucus samples was classified as good. In conclusion, although a full step-wise post-mortem examination remains the most proper way of investigating small ruminant abortions, the easily accessible, low-threshold tools for practitioners and farmers as described in this paper not only provide reliable results compared to results of the post-mortem examination but also stimulates farmers and veterinarians to submit fetuses and placentas if necessary. Suggestions for further improvement of both alternatives have been summarized. Both alternatives could also be tailor-made for specific regions with their specific causes of abortion.

Rickettsiales in Italy

There is no updated information on the spread of Rickettsiales in Italy. The purpose of our study is to take stock of the situation on Rickettsiales in Italy by focusing attention on the species identified by molecular methods in humans, in bloodsucking arthropods that could potentially attack humans, and in animals, possible hosts of these Rickettsiales. A computerized search without language restriction was conducted using PubMed updated as of December 31, 2020. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was followed. Overall, 36 species of microorganisms belonging to Rickettsiales were found. The only species identified in human tissues were Anaplasma phagocytophilum,Rickettsia conorii, R. conorii subsp. israelensis, R. monacensis, R. massiliae, and R. slovaca. Microorganisms transmissible by bloodsucking arthropods could cause humans pathologies not yet well characterized. It should become routine to study the pathogens present in ticks that have bitten a man and at the same time that molecular studies for the search for Rickettsiales can be performed routinely in people who have suffered bites from bloodsucking arthropods.

Importation of Ticks on Companion Animals and the Risk of Spread of Tick-Borne Diseases to Non-Endemic Regions in Europe

Increased human mobility elevates the risk of exposure of companion animals travelling with their owners or imported from other regions to tick attacks. In this study, we highlight the potential role of dogs and cats taken for tourist trips or imported animals in the spread of ticks and tick-borne pathogens. The Rhipicephalus sanguineus tick, which is a vector of numerous pathogens causing diseases in animals and humans, is imported most frequently from endemic areas to many European countries. Additionally, alien tick species with high epizootic and epidemiological importance can be imported on dogs from other continents. Companion animals play an even greater role in the spread of autochthonous tick species and transmission of tick pathogens to other animals and humans. Although the veterinary and medical effects of the parasitism of ticks carried by companion animals travelling with owners or imported animals are poorly assessed, these animals seem to play a role in the rapid spread of tick-borne diseases. Development of strategies for protection of the health of companion animals in different geographic regions should take into account the potential emergence of unknown animal tick-borne diseases that can be transmitted by imported ticks.

Sheep experimentally infected with a human isolate of Anaplasma phagocytophilum serve as a host for infection of Ixodes scapularis ticks

Anaplasma phagocytophilum, first identified as a pathogen of ruminants in Europe, has more recently been recognized as an emerging tick-borne pathogen of humans in the U.S. and Europe. A. phagocytophilum is transmitted by Ixodes spp., but the tick developmental cycle and pathogen/vector interactions have not been fully described. In this research, we report on the experimental infection of sheep with the human NY-18 isolate of A. phagocytophilum which then served as a host for infection of I. scapularis nymphs and adults. A. phagocytophilum was propagated in the human promyelocytic cell line, HL-60, and the infected cell cultures were then used to infect sheep by intravenous inoculation. Infections in sheep were confirmed by PCR and an Anaplasma-competitive ELISA. Clinical signs were not apparent in any of the infected sheep, and only limited hematologic and mild serum biochemical abnormalities were identified. While A. phagocytophilum morulae were rarely seen in neutrophils, blood film evaluation revealed prominent large granular lymphocytes, occasional plasma cells, and rare macrophages. Upon necropsy, gross lesions were restricted to the lymphoid system. Mild splenomegaly and lymphadenomegaly with microscopic evidence of lymphoid hyperplasia was observed in all infected sheep. Female I. scapularis that were allowed to feed and acquire infection on each of the 3 experimentally infected sheep became infected with A. phagocytophilum as determined by PCR of guts (80-87%) and salivary glands (67-100%). Female I. scapularis that acquired infection as nymphs on an experimentally infected sheep transmitted A. phagocytophilum to a susceptible sheep, thus confirming transstadial transmission. Sheep proved to be a good host for the production of I. scapularis infected with this human isolate of A. phagocytophilum, which can be used as a model for future studies of the tick/pathogen interface.