Efficacy assessment of PEV2 phage on Galleria mellonella larvae infected with a Pseudomonas aeruginosa dog otitis isolate.

Pseudomonas (P.) aeruginosa is the most frequently isolated Gram-negative bacteria in dog otitis. Antimicrobial resistance is particularly prevalent in P. aeruginosa and phage therapy represents a promising alternative therapeutic strategy. The aim of this study was to assess the efficacy of the PEV2 phage against a clinical P. aeruginosa isolate from a canine otitis using a Galleria (G.) mellonella larvae model. The genomic DNA of PAV237 P. aeruginosa isolate was sequenced and analysed. In a first main experiment, the efficacy of PEV2 phage against PAV237 was assessed at different multiplicities of infection (MOI) (50,000, 5000, 500, 50) by analyzing the larvae survival rate during 4 days. In a second experiment, the bacterial and phage titer evolutions were assessed depending on two MOIs (50,000, 5000). No significant survival increase was observed with PEV2 therapy in the infected larvae groups. The generated Kaplan-Meier curves showed that the rate of alive larvae was significantly higher in the non-infected larvae compared to the infected-treated ones irrespective of phage MOIs. An increase of the phage titer was observed at 24 and 48 h post-inoculation (HPI) with both MOIs and the P. aeruginosa titers were lower with MOI 50,000 and 5000 compared to the infectivity control at 24 and 48 HPI. Even if an ineffectiveness of the PEV2 phage was observed on the larvae survival, PEV2 is active against P. aeruginosa in this model and PEV2 replication is correlated with a lower bacterial proliferation in the phage treated larvae.

[Plasma hemoglobin. Comparison between 2 methods of determination]. / Hémoglobine plasmatique. Comparison entre deux méthodes de dosage.

The methods used to titrate plasmatic haemoglobin, an analysis which is of great interest to cardiac surgery, must be very accurate because the levels are much lower than those found in whole blood. This work introduces a comparison between two methods: the ammoniacal water method and Cripps's differential method. After studying various criteria (repeatability, limit of detection, accuracy, reference values, stability of the reaction), and after studying the correlation between each method and the benzidin method, used as reference method, as well as the correlation between all of them, Cripp's method turns out to be the closest to the benzidin method, as well as being simpler, more accurate, more specific, and also easier to use than the ammoniacal water method, the only problem occurring at the stage of the preparation of the standard solution.

[Serologic and clinical study of post-transfusion viral contamination after cardiac surgery. Excluding human immunodeficiency virus]. / Etude sérologique et clinique des contaminations virales post-transfusionnelles après chirurgie cardiaque. En dehors du virus d'immunodéficience humaine.

The incidence of post-transfusion viral contamination after cardiac surgery is variable but not negligible. The serological and clinical features of such contamination were determined in a series of 100 consecutive patients seen between June, 1983 and January, 1984. The ELISA technique was used for hepatitis A and B viruses and cytomegalovirus on three samples of blood taken before (S1), and 15 days (S2) and 2 to 3 months (S3) after surgery. In case of hepatitis further investigations were performed for heterophilic infectious mononucleosis antibodies and for hepatitis B virus DNA. The transient appearance at S2 of anti-cytomegalovirus antibodies brought by transfusion was observed in 40% of the cases; seroconversion occurred in 4% (cytomegalovirus 3, hepatitis B virus 1), and 5% of the patients developed clinical and biochemical hepatitis without serological markers.

[Activated thromboplastin time, plasma heparin and plasma fibrinogen using the Fibrintimer 10]. / Temps de céphaline activé, héparinémie et fibrinogène plasmatique sur Fibrintimer 10.

After a thorough study, and having chosen the machine that is to equip an average sized haemostasis laboratory, the installation then requires certain steps (the reorganisation of work, better adapted reagents, a change of normality, a fine tuning of the technics, the time to get used to the machine). In this perspective, this work describes the regulation of the technic to determine the heparin activity on the Fibrintimer 10 (F 10) by chronometry (thrombin clotting time with variable concentration), a study of the repeatability and reproducibility of activated partial thromboplastin time (APTT), plasma heparin (HEP) and fibrinogen on the Fibrintimer 10, a study of the correlation between the results we got with the F 10 and the thermostat water-bath for the APTT and the HEP and between those we got on the F 10 and the fibrometer for the fibrinogen. The F 10 has allowed us to save more time whilst keeping the same technics and reagents. The determination of the heparin activity, by thrombin clotting time with variable concentration, gives us a method which is quick, cheap and useful for the following-up of the patients undergoing a treatment with standard heparin. The reproducibility and repeatability prove to be good for the 3 tests in our operatory conditions as well as the correlations between the results we get with both methods.