Survival of Rickettsia conorii in artificially contaminated whole and leukoreduced canine blood units during the storage period

Abstract

Background: The ability of tick-borne agents to survive in stored blood bags is a key factor for their transmissibility by blood transfusion. The aim of this study was to evaluate the survival and potential infectivity of Rickettsia conorii (RC) in artificially contaminated canine whole blood (WB) and in leukoreduced whole blood (LR-WB) during the storage period. Methods: RC was cultured on L929 cells. We used a one-week 25-cm 2 flask with 70-80% of L929 infected cells to prepare the bacterial inoculum by pelleting cells and suspending the pellet in the donors' serum. We infected five 100 ml WB units with RC within 2 h from the collection and maintained it at room temperature for 4 h prior to refrigeration. We filtered 50 ml of each WB bag to obtain leukoreduced WB (LR-WB) at day 1 post-infection (dpi). We checked WB and LR-WB bags at 1, 4, 7, 14, 21, 28, 35 dpi for RC presence and viability through real-time PCR (rPCR) for DNA and mRNA, respectively, and by isolation. Identification of isolates was confirmed by indirect immunofluorescence and rPCRs. Results: RC survived for the entire storage period in both whole and leukoreduced blood. All bags contained viable bacteria until 7 dpi; RC viability generally decreased over time, particularly in LR-WB bags where the isolation time was longer than in WB. Viable bacteria were still isolated at 35 dpi in 3 WB and 3 LR-WB. Conclusions: Leukoreduction reduced but did not eliminate RC in infected units. The survival and infectivity of RC in canine blood during the storage period may represent a threat for recipients.

Randomized double‐blinded clinical trial on acute transfusion reactions in dogs receiving leukoreduced versus nonleukoreduced packed red blood cells

“…16 Prestorage leukoreduction reduces the incidence of FNHTRs in human medicine from 50% to 80%, 32,33,35,36 most likely by abrogating the accumulation of these cytokines. 10 In vitro studies show that leukoreduction is effective in decreasing the levels of IL-6 and IL-8 in canine stored blood, 11,37,38 decreasing the presence of Rickettsia conorii in infected blood units, 39 preventing the release of vascular endothelial growth factor (VEGF) during storage 28 and decreasing procoagulant activity in stored PRBC. 29 In healthy dogs leukoreduction decreases the inflammatory response to transfusion of 21-day old PRBC, 40 measured by white blood cell and segmented neutrophil counts, fibrinogen concentration and C-reactive protein values.…”

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS). Part 1: Definitions and clinical signs

“…Haemobartonella canis 146,147 -dog Candidatus Mycoplasma haematoparvum 148 -dog Anaplasma phagocytophilum 192 -dog Rickettsia conorii 193 -dog Bartonella henselae 194,195 -catMycoplasma haemofelis , 196 'Candidatus Mycoplasma haemominutum' 197 -cat…”

Rickettsia species in Dermacentor reticulatus ticks feeding on human skin and clinical manifestations of tick-borne infections after tick bite

“…The risk of transfusion-transmitted Rickettsia is unknown, however, single cases of R. rickettsia and R. parkeri have been described so far 57 , 58 . Lucchese and co-authors 59 have demonstrated that R. conorii was able to remain viable in dog blood stored until 35 days. Therefore further studies about the risk of transfusion-transmitted Rickettsia infection are essential, especially if we take into account that blood recipients are often immunosuppressed 60 .…”