Pseudomonas fluorescens contamination of a feline packed red blood cell unit and studies of canine units.

BACKGROUND: While screening programs have reduced the risk of infectious disease transmission by donors in human and veterinary blood banking, bacterial contamination of blood products has emerged as a major complication in human medicine. OBJECTIVES: To describe a Pseudomonas fluorescens (Pf)-contaminated feline packed RBC (pRBC) unit and experimentally investigate Pf-contaminated canine pRBCs. METHODS: Canine pRBCs were inoculated with Pf-rich pRBCs from the sentinel feline unit and stored at 4 degrees C or 20 degrees C for 72 hours. Aliquots from the pRBCs were serially evaluated by microscopy, culture, and a eubacterial 16S rRNA real-time PCR assay. RESULTS: One Pf-contaminated feline unit turned black after 22 days of storage and was removed from the blood bank; a source was not found, and no other contaminated units were identified. Canine pRBCs spiked with 5 or 25 microL of the sentinel unit became culture- and/or 16S PCR-positive at > or =8 hours at 20 degrees C and 48 hours at 4 degrees C and developed a color change at > or =24 hours. Sensitivity studies indicated that without incubation, inoculation of > or =100 microL Pf-rich pRBCs was necessary for a positive 16S PCR test result. CONCLUSIONS: P. fluorescens grows in stored pRBCs slowly at 4 degrees C and rapidly at 20 degrees C. Screening of blood products for color change, estimating bacterial concentration with microscopy, and 16S PCR testing are simple and fast ways to detect bacteria in stored blood. Aseptic collection, temperature-controlled storage, and regular visual monitoring of stored units is recommended. Discolored units should not be transfused, but examined for bacterial contamination or other blood product quality problems.

Canine Dal blood type: A red cell antigen lacking in some Dalmatians.

BACKGROUND: Based upon alloantibodies produced after sensitizing dogs with transfused blood, more than a dozen blood group systems have been recognized thus far, and some have been classified as dog erythrocyte antigens (DEA). HYPOTHESIS: A new canine red cell antigen was suspected, based on the development of specific alloantibodies in a Dalmatian previously sensitized by blood transfusions. ANIMALS: Twenty-six Dalmatians (including 1 Dalmatian in need of blood compatibility studies); 55 canine blood donors. METHODS: Serologic tests, including blood typing, crossmatching, and direct Coombs' test were performed by standard tube techniques and a novel gel column technology adapted from human blood banking. RESULTS: By day 40 after transfusion of an anemic Dalmatian, all major crossmatch tests to 55 non-Dalmatian dogs were incompatible. The 2 initial donors, who were compatible before transfusion, were also now incompatible, suggesting the development of an alloantibody to a common red cell antigen. No siblings were available, but 4 of 25 unrelated Dalmatians were crossmatch compatible, suggesting that they were missing the same red cell antigen. The patient was blood typed DEA 1.1, 3, 4, and 5 positive, but DEA 7 negative. Further blood typing and crossmatching results did not support an association to any of these known blood types. The alloantibodies produced were determined to be of the immunoglobulin G class. CONCLUSIONS AND CLINICAL IMPORTANCE: Based upon the identification of an acquired alloantibody in a Dalmatian, a presumably new common blood type named Dal was identified. Dalmatians lacking the Dal antigen are likely at risk of delayed and acute hemolytic transfusion reactions.

A newly recognized blood group in domestic shorthair cats: the Mik red cell antigen.

BACKGROUND: Naturally occurring alloantibodies produced against A and B red cell antigens in cats can cause acute hemolytic transfusion reactions. Blood incompatibilities, unrelated to the AB blood group system, have also been suspected after blood transfusions through routine crossmatch testing or as a result of hemolytic transfusion reactions. HYPOTHESIS: Incompatible crossmatch results among AB compatible cats signify the presence of a naturally occurring alloantibody against a newly identified blood antigen in a group of previously never transfused blood donor cats. The associated alloantibody is clinically important based upon a hemolytic transfusion reaction after inadvertent transfusion of red cells expressing this red cell antigen in a feline renal transplant recipient that lacks this red cell antigen. METHODS: Blood donor and nonblood donor cats were evaluated for the presence of auto- and alloantibodies using direct antiglobulin and crossmatch tests, respectively, and were blood typed for AB blood group status. Both standard tube and novel gel column techniques were used. RESULTS: Plasma from 3 of 65 cats and 1 feline renal transplant recipient caused incompatible crossmatch test results with AB compatible erythrocytes indicating these cats formed an alloantibody against a red cell antigen they lack, termed Mik. The 3 donors and the renal transplant recipient were crossmatch-compatible with one another. Tube and gel column crossmatch test results were similar. CONCLUSIONS AND CLINICAL IMPORTANCE: The absence of this novel Mik red cell antigen can be associated with naturally occurring anti-Mik alloantibodies and can elicit an acute hemolytic transfusion reaction after an AB-matched blood transfusion.

Impact of time-limited feeding and dietary carbohydrate content on weight loss in group-housed cats.

Twenty-four adult cats were transitioned to time-limited feeding and randomized to either a dry low carbohydrate diet (LC) or a dry reduced energy diet (HC). In Trial 1 the LC and HC groups received equal amounts of food (by weight) for 13 weeks. Both groups consumed all food offered, hence the LC group received more energy/day than the HC group. In Trial 2 all cats were fed the LC diet for 12 weeks, but each group received the energy that the opposite group had received in Trial 1. In Trial 1 only the overweight HC cats (body condition score> 6/9) experienced a significant change in body weight (-0.52 +/- 0.08 kg). In Trial 2, LC/Low Calorie overweight cats lost 0.62 +/- 0.10 kg, whereas, the LC/High Calorie normal weight cats gained 0.68 +/- 0.05 kg. In conclusion, body condition and energy intake but not type of diet influenced weight in this cohort of group-housed cats.