Comparison of methicillin-resistant Staphylococcus pseudintermedius adherence to 2 canine limb salvage endoprosthesis implants.

The objective of our study was to compare adhesion of methicillin-resistant Staphylococcus pseudintermedius (MRSP) to stainless steel (SS) and to tantalum (TA) canine limb salvage endoprosthesis implants in an in vitro experimental study. The median of the mean log10 colony forming units/mL for adherent MRSP was 4.96 (range: 4.63 to 6.33) for the TA endoprosthesis and 4.31 (range: 3.86 to 5.05) for the SS endoprosthesis (P = 0.009). Although the trabecular and porous design of the TA endoprosthesis provides mechanical benefits over the SS endoprosthesis, it may increase the risk of developing infection due to higher levels of bacterial adherence.

Comparaison de l'adhérence deStaphylococcus pseudintermediusrésistant à la méthicilline à deux implants d'endoprothèse pour sauver des membres canins. L'objectif de notre étude consistait à comparer l'adhésion de Staphylococcus pseudintermedius résistant à la méthicilline (MRSP) à des implants d'endoprothèse en acier inoxydable (AI) et en tantale (TA) pour sauver des membres canins lors d'une étude expérimentale in vitro. La médiane des moyennes en log10 des unités formatrices de colonies/mL pour le MRSP adhérent était de 4,96 (écart : de 4,63 à 6,33) pour l'endoprothèse TA et 4,31 (écart : de 3,86 à 5,05) pour l'endoprothèse d'AI (P = 0,009). Même si la conception trabéculaire et poreuse de l'endoprothèse de TA offre des avantages mécaniques par rapport à l'endoprothèse d'AI, elle peut accroître le risque de développer une infection en raison des taux supérieurs d'adhérence bactérienne.(Traduit par Isabelle Vallières).

Perioperative characteristics of dogs undergoing open versus laparoscopic-assisted cystotomy for treatment of cystic calculi: 89 cases (2011-2015).

OBJECTIVE To compare perioperative characteristics of dogs with cystic calculi treated via open versus laparoscopic-assisted cystotomy (LAC). DESIGN Retrospective case series. ANIMALS 89 client-owned dogs that underwent open cystotomy (n = 39) or LAC (50). PROCEDURES Medical records of dogs that underwent cystotomy between 2011 and 2015 were reviewed. History, signalment, surgery date, results of physical examination, results of preoperative diagnostic testing, details of surgical treatment, duration of surgery, perioperative complications, treatment costs, and duration of hospitalization were recorded. RESULTS 5 of 50 (10%) dogs required conversion from LAC to open cystotomy (OC). There was no significant difference between the LAC (1/50) and OC (2/39) groups with regard to percentage of patients with incomplete removal of calculi. Duration of surgery was not significantly different between the LAC (median, 80 min; range, 35 to 145 min) and OC (median, 70 min; range, 45 to 120 min) groups. Postoperative duration of hospitalization was significantly shorter for dogs that underwent LAC (median, 24 hours; range, 12 to 48 hours) versus OC (median, 26 hours; range, 12 to 63 hours). Surgical and total procedural costs were significantly higher for patients undergoing LAC. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that LAC may be an acceptable minimally invasive technique for treatment of cystic calculi in dogs. Surgery times were similar to those for dogs undergoing OC; however, surgical and total procedural costs were higher. Further investigation is suggested to determine which patients may benefit from LAC versus traditional OC.

Adherence of methicillin-resistant Staphylococcus pseudintermedius to suture materials commonly used in small animal surgery.

OBJECTIVE: To evaluate adherence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) to 5 suture materials commonly used in small animal surgery. SAMPLE: 10 epidemiologically unrelated MRSP isolates (obtained from dogs with clinical infections) that had strong biofilm-forming ability and 5 types of suture. PROCEDURES: The 5 types of suture evaluated were monofilament polyglecaprone 25, monofilament polydioxanone, triclosan-coated (TC)-monofilament polydioxanone, braided polyglactin 910, and barbed monofilament polydioxanone. Suture segments were incubated in standard suspensions of MRSP for 2 minutes. Segments were then placed in tryptone soy broth and incubated overnight. After incubation, segments were rinsed with PBS solution and sonicated to dislodge adherent bacteria. Resulting suspensions were used to create serial dilutions that were plated, incubated overnight, and counted the following day. Bacterial adherence to 1 segment of each suture type was assessed by use of scanning electron microscopy. RESULTS: There was significantly less adherence of MSRP to TC-monofilament polydioxanone than to polyglecaprone 25, polyglactin 910, barbed monofilament polydioxanone, and monofilament polydioxanone. There was significantly less adherence of MSRP to polyglecaprone than to polyglactin 910. CONCLUSIONS AND CLINICAL RELEVANCE: Barbed suture had a bacterial adherence profile comparable to that for monofilament suture. Adherence of MRSP was greatest for braided polyglactin 910. Use of TC-monofilament polydioxanone can be considered for patients that are at high risk of developing surgical site infections and for which a surgeon chooses a multifilament suture.

Impact of polymethylmethacrylate additives on methicillin-resistant Staphylococcus pseudintermedius biofilm formation in vitro.

OBJECTIVE: To evaluate the impact of gentamicin, silver, or both additives in polymethylmethacrylate (PMMA) beads on methicillin-resistant Staphylococcus pseudintermedius (MRSP) biofilm formation in vitro. SAMPLE: 4 preparations of PMMA beads (formed with no additive [control], gentamicin, silver, and gentamicin and silver). PROCEDURES: Beads from each group were exposed to 10 MRSP isolates known to be strong biofilm formers. Following incubation, the beads were rinsed to remove planktonic bacteria, then sonicated to dislodge biofilm-associated bacteria. Resulting suspensions were serially diluted, plated on blood agar, and incubated overnight; CFUs were counted. Variance of mean CFU counts following log10 transformation was analyzed among PMMA groups. RESULTS: None of the PMMA additives tested completely inhibited MRSP biofilm formation. There was a significant effect of gentamicin and gentamicin plus silver on this variable, compared with controls, but not of silver alone. There was no difference between gentamicin and gentamicin plus silver. When only isolates not susceptible to gentamicin were evaluated, there were no significant differences among PMMA additive groups. Within gentamicin-susceptible isolates, there was an impact of gentamicin and gentamicin plus silver, but no impact of silver alone and no difference between gentamicin and gentamicin plus silver. CONCLUSIONS AND CLINICAL RELEVANCE: Gentamicin-impregnated PMMA was effective at reducing biofilm formation of gentamicin-susceptible MRSP isolates but had no effect on isolates not susceptible to gentamicin. Silver-impregnated PMMA had no effect on MRSP biofilm formation. Results suggested that gentamicin-impregnated PMMA may not be effective in vivo against MRSP isolates not susceptible to gentamicin. Antibacterial efficacy of silver should not be assumed without proper testing of the target bacteria and specific silver compound.