Bacteriological and serological findings in a further case of transfusion-mediated Yersinia enterocolitica sepsis

Vitronectin Binds to a Specific Stretch within the Head Region of Yersinia Adhesin A and Thereby Modulates Yersinia enterocolitica Host Interaction

Complement resistance is an important virulence trait of Yersinia enterocolitica (Ye). The predominant virulence factor expressed by Ye is Yersinia adhesin A (YadA), which enables bacterial attachment to host cells and extracellular matrix and additionally allows the acquisition of soluble serum factors. The serum glycoprotein vitronectin (Vn) acts as an inhibitory regulator of the terminal complement complex by inhibiting the lytic pore formation. Here, we show YadA-mediated direct interaction of Ye with Vn and investigated the role of this Vn binding during mouse infection in vivo. Using different Yersinia strains, we identified a short stretch in the YadA head domain of Ye O:9 E40, similar to the 'uptake region' of Y. pseudotuberculosis YPIII YadA, as crucial for efficient Vn binding. Using recombinant fragments of Vn, we found the C-terminal part of Vn, including heparin-binding domain 3, to be responsible for binding to YadA. Moreover, we found that Vn bound to the bacterial surface is still functionally active and thus inhibits C5b-9 formation. In a mouse infection model, we demonstrate that Vn reduces complement-mediated killing of Ye O:9 E40 and, thus, improved bacterial survival. Taken together, these findings show that YadA-mediated Vn binding influences Ye pathogenesis.

Extracellular accumulation of bioactive substances; Interleukin-1β (IL-1β) and plasminogen activator inhibitor-1 (PAI-1) in stored blood units and relation to bacterial contamination

Bacterial contamination of blood and its cellular components remains an unresolved problem in transfusion medicine and is considered to be the most common microbiological cause of transfusion associated morbidity and mortality. The present work was designed to explore the levels of two bioactive compounds interleukin-1 beta (IL-1beta) and plasminogen activator inhibitor-1 (PAI-1) in stored blood units and their relation to bacterial contamination of these units. This study was conducted on 112 blood units obtained from blood bank of Mansoura University Children Hospital. Sequential blood samples were obtained both immediately at donation and after 10 days for measurement of IL-1beta and PAI-1 and for bacterial culture by BACTEC 9050 system. There was statistically significant increase in both IL-1 beta and PAI-1 (P = 0.0001) after 10 days of blood units storage. Bacteriological culture revealed no growth in 68% and positive growth in 32% of blood units. The commonest isolated organism was Staphylococcus aureus (15%) followed by Staphylococcus epidermedis (13%) then Yersinia sp. and Enterobacter sp. (2%) for each. From the present study we could conclude that stored blood units contain platelets and WBCs derived bioactive substances PAI-1 and IL-1beta which increase with the duration of blood storage. Furthermore, the extended duration of storage carries the danger of blood contamination by bacteria. Automated blood culture system seems to be helpful in identification of bacterial contamination of blood units. We recommend fresh blood transfusion as early as possible and the practice of Leucofiltration to avoid blood transfusion complications.

Pathogenicity of Bacteria Contaminating Blood Products

SUMMARY: Bacterial contaminations of blood products often originate from the flora of the donor. Normally, components of the skin flora less frequently give rise to severe or complicated infections, although their participation in such conditions has been described. In contrast, bacteria that can cause infections in immunocompetent persons may give rise to life-threatening infections when present in blood products. The latter microorganisms are well-equipped with a variety of virulence factors that contribute to their pathogenicity.

Protective roles for fibrin, tissue factor, plasminogen activator inhibitor-1, and thrombin activatable fibrinolysis inhibitor, but not factor XI, during defense against the gram-negative bacterium Yersinia enterocolitica

Septic infections dysregulate hemostatic pathways, prompting coagulopathy. Nevertheless, anticoagulant therapies typically fail to protect humans from septic pathology. The data reported in this work may help to explain this discrepancy by demonstrating critical protective roles for coagulation leading to fibrin deposition during host defense against the Gram-negative bacterium Yersinia enterocolitica. After i.p. inoculation with Y. enterocolitica, fibrinogen-deficient mice display impaired cytokine and chemokine production in the peritoneal cavity and suppressed neutrophil recruitment. Moreover, both gene-targeted fibrinogen-deficient mice and wild-type mice treated with the anticoagulant coumadin display increased hepatic bacterial burden and mortality following either i.p. or i.v. inoculation with Y. enterocolitica. Mice with low tissue factor activity succumb to yersiniosis with a phenotype similar to fibrin(ogen)-deficient mice, whereas factor XI-deficient mice show wild-type levels of resistance. Mice deficient in plasminogen activator inhibitor-1 or thrombin-activatable fibrinolysis inhibitor display modest phenotypes, but mice deficient in both plasminogen activator inhibitor-1 and thrombin-activatable fibrinolysis inhibitor succumb to yersiniosis with a phenotype resembling fibrin(ogen)-deficient mice. These findings demonstrate critical protective roles for the tissue factor-dependent extrinsic coagulation pathway during host defense against bacteria and caution that therapeutics targeting major thrombin-generating or antifibrinolytic pathways may disrupt fibrin-mediated host defense during Gram-negative sepsis.

Spondylodiscitis of the lumbar spine in a non-immunocompromised host caused by Yersinia enterocolitica O:9

Here presented is an extremely rare case of a spinal osteomyelitis (L5-S1) with epidural empyema in a non-immunocompromised 62-year-old man caused by Yersinia enterocolitica O:9. The infection occurred acutely and required immediate surgical treatment. Y. enterocolitica was cultured from the empyema fluid, wound swabs of the intervertebral disc L5-S1 and stool cultures. Following the surgical decompression and antibiotic treatment, the patient recovered completely, without neurological deficits. A review of the literature revealed only sparse cases of spondylodiscitis due to other Y. enterocolitica serogroups. To our knowledge, we report here the first case of a spondylodiscitis of the lumbar spine caused by Y. enterocolitica serovar O:9 in a non-immunocompromised patient.

Seroepidemiological survey of pathogenic Yersinia in breeding squirrel monkeys in Japan

To investigate the prevalence of antibodies to pathogenic Yersinia in breeding squirrel monkeys, the serum samples of 252 squirrel monkeys from 9 zoological gardens in Japan were tested by ELISA using plasmid-encoded Yersinia outer membrane protein (Yops) as the antigen. The cutoff value was calculated by using the serum samples of the squirrel monkeys from Suriname, where no prevalence of pathogenic Yersinia have been reported. According to the cutoff value, 164 of 252 (65.1%) squirrel monkeys were considered positive against pathogenic Yersinia. These positive monkeys belonged to 8 of the 9 zoological gardens, and the percentage of the seropositive monkeys ranged from 22.2 to 89.4%. Furthermore, in one zoological garden, the positive rate of the squirrel monkeys which were over 1 year old (95.7%) was significantly higher than those which were under 1 year old (23.3%). These results suggested that pathogenic Yersinia is highly prevalent among breeding monkeys in Japan.

Transfusion-transmitted Klebsiella pneumoniae fatalities, 1995 to 2004

Transfusion-transmitted bacterial sepsis is the third most common cause of transfusion-related fatalities reported to the Food and Drug Administration. Between October 1, 1995, and September 30, 2004, there were 665 reported transfusion fatalities. Eighty-five (13%) deaths were due to transfusion-transmitted bacterial infections, of which 58 (68%) were due to gram-negative organisms. The most common gram-negative organism associated with transfusion-transmitted deaths after receipt of platelets was Klebsiella pneumoniae. This article summarizes retrospectively the case series of deaths due to transfusion-transmitted K pneumoniae infection, reported to the Food and Drug Administration, 1995 to 2004. There were 12 deaths due to transfusion-transmitted K pneumoniae infection with 7 (58%) of the 12 cases occurring in 2002. Eleven deaths were caused by the transfusion of contaminated platelets and 1 death attributed to contaminated red blood cells. Extensive review of the seven 2002 fatality reports did not identify a common (shared) lot for items used during collection or processing of the blood product. In conclusion, in cases of suspected transfusion-transmitted septicemia, broad spectrum antibiotic coverage including coverage of gram-negative organisms should be considered. Strict adherence to infection control measures while collecting, processing, and handling all blood and blood components in both the clinical settings and in the laboratory should be followed. Further development of simple and effective test procedures for detecting bacteria in the blood is needed.

Detection of bacteria in red blood cell concentrates by the Scansystem method

Bacterial contamination remains one of the major risks associated with blood product transfusion. The kinetics of bacterial growth in red blood cell concentrates (RBCC) is different than otherwise due to storage at 4 degrees C, conditions in which most bacteria do not survive. Psychrophilic bacteria such as Yersinia enterocolitica, however, can proliferate from a very low level of contamination to clinically significant levels at 4 degrees C and are known to cause severe transfusion-related infections. A screening method allowing the early detection of very low levels of bacteria in RBCC would improve transfusion safety. The Scansystem method has been previously described for detection of bacteria in platelet concentrates. We present here a modification of the system for detection of low levels of bacteria in RBCC. The Scansystem RBC kit protocol requires three steps, i.e., the agglutination and selective removal of RBCs, a labeling stage during which bacteria are labeled with a DNA-specific fluorophore, and finally recovery of bacteria on the surface of a black membrane for analysis using the Scansystem. The entire procedure from sampling to result can be completed in 90 min. Both gram-negative and gram-positive bacteria in RBCC are detected with a higher sensitivity than with currently available culture-based methods. The Scansystem RBC kit is shown to be sensitive enough to identify low-level bacterial contamination in a single unit tested in a pool of up to 20 RBCC samples (detection limit of between 1 and 10 CFU/ml depending on the bacterial strain). The method therefore lends itself to incorporation into high-sample-throughput screening programs.

Three years of haemovigilance in a general university hospital

The aim of this study is to describe a newly implemented haemovigilance system in a general university hospital. We present a series of short cases, highlighting particular aspects of the reports, and an overview of all reported incidents between 1999 and 2001. Incidents related to transfusion of blood products were reported by the clinicians using a standard preformatted form, giving a synopsis of the incident. After analysis, we distinguished, on the one hand, transfusion reactions, that are transfusions which engendered signs or symptoms, and, on the other hand, the incidents where management errors and/or dysfunctions took place. Over 3 years, 233 incidents were reported, corresponding to 4.2 events for 1000 blood products delivered. Of the 233, 198 (85%) were acute transfusion reactions and 35 (15%) were management errors and/or dysfunctions. Platelet units gave rise to statistically (P < 0.001) more transfusion reactions (10.7 per thousand ) than red blood cells (3.5 per thousand ) and fresh frozen plasma (0.8 per thousand ), particularly febrile nonhaemolytic transfusion reactions and allergic reactions. A detailed analysis of some of the transfusion incident reports revealed complex deviations and/or failures of the procedures in place in the hospital, allowing the implementation of corrective and preventive measures. Thus, the haemovigilance system in place in the 'Centre Hospitalier Universitaire Vaudois, CHUV' appears to constitute an excellent instrument for monitoring the security of blood transfusion.

Prevention of Yersinia enterocolitica, Pseudomonas fluorescens, and Pseudomonas putida outgrowth in deliberately inoculated blood by a novel pathogen-reduction process

BACKGROUND

Yersinia enterocolitica, Pseudomonas fluorescens, and P. putida are responsible for a significant amount of the bacterial sepsis cases attributed to RBC transfusions. INACTINE is a pathogen-reduction process for RBCs, which consists of incubation of RBCs with PEN110 (proprietary compound) followed by automated washing of the RBCs. INACTINE is an electrophilic agent, which inactivates a wide range of viruses and WBCs by disruption of nucleic acid replication. The present study investigated the effect of the PEN110 process on Y. enterocolitica, P. fluorescens, and P. putida.

STUDY DESIGN AND METHODS

Identical units of reduced CPD/ADSOL additive solution (AS-1) or CP2D/Nutricel additive solution (AS-3) RBCs were inoculated with 10 to 100 CFU per mL of either Y. enterocolitica, P. fluorescens, or P. putida. The control units were put on storage immediately after the bacterial spike. The test units were subjected to the PEN110 process and then stored. Sham control units were processed the same way as test units without addition of PEN110. Bacterial titer in all units was monitored during the 6-week storage period.

RESULTS

No bacteria were detected in any of the RBC units (n = 9 for each microorganism) prepared using the PEN110 process throughout 6 weeks of storage. Substantial bacterial growth occurred in all control and in a majority of sham control units (11 out of 15 experiments). The bacterial inactivation by the INACTINE process was found to be equally effective in CPD/AS-1 and CP2D/AS-3 RBC units.

CONCLUSION

The INACTINE process effectively prevented the outgrowth of Y. enterocolitica, P. fluorescens, and P. putida deliberately inoculated into WBC-reduced CPD/AS-1 and CP2D/AS-3 RBCs. The results demonstrated the crucial bactericidal role of PEN110 in the INACTINE process.

Identification of Yersinia-infected blood donors by anti-Yop IgA immunoassay

BACKGROUND

From 1991 through 1996, nine transfusion-related cases of septicemia and endotoxemia occurred in New Zealand, a rate approximately 80 times that in the United States. Eight cases involved the transfusion of Yersinia enterocolitica-infected blood and one involved Serratia liquefaciens-infected blood. Six of the recipients died. Donor exclusion by recent gastrointestinal illness failed to prevent the four most recent such infections, and it has led to an estimated 3- to 5-percent rate of donor deferral.

STUDY DESIGN AND METHODS

An antigen preparation containing the released proteins (Yops) of Y. enterocolitica was used to establish an EIA to detect IgA directed against these proteins in donated blood. The assay was tested with serum from donors in transfusion-related endotoxemia cases, subjects who were stool culture-positive for Y. enterocolitica, and 495 healthy volunteer blood donors.

RESULTS

The assay detected anti-Yop IgA in the donors of all 6 infected units tested. Ninety-six percent of culture-positive subjects tested positive, whereas there was 70-percent positivity with a commercial immunoassay based on lipopolysaccharide. Five percent of random donors tested positive; only one of these had Y. enterocolitica present in a stool sample, and none were bacteremic.

CONCLUSION

The anti-Yop immunoassay used in this study could be applied to reduce the risk of posttransfusion endotoxic shock caused by Y. enterocolitica.

Non-infectious complications of transfusion therapy

Blood transfusion is considered safe when the infused blood is tested using state of the art viral assays developed over the past several decades. Only rarely are known viruses like HIV and hepatitis C transmitted by transfusion when blood donors are screened using these sensitive laboratory tests. However, there are a variety of transfusion risks which still remain that cannot be entirely eliminated, many of which are non-infectious in nature. Predominantly immune-mediated complications include the rapid intravascular or slow extravascular destruction (hemolysis) of transfused red cells or extravascular removal of platelets by pre-formed antibodies carried by the transfusion recipient. Alternatively, red cells can be damaged when exposed to excessive heat or incompatible intravenous fluids before or during the transfusion. Common complications of blood transfusion that at least partly involve the immune system include febrile non-hemolytic and allergic reactions. While these are usually not life-threatening, they can hamper efforts to transfuse a patient. Other complications include circulatory overload, hypothermia and metabolic disturbances. Profound hypotensive episodes have been described in patients on angiotensin-converting enzyme (ACE) inhibitors who receive platelet transfusions through bedside leukoreduction filters. These curious reactions appear to involve dysmetabolism of the vasoactive substance bradykinin. Products contaminated by bacteria during blood collection and transfused can cause life-threatening septic reactions. A long-term complication of blood transfusion therapy unique to chronically transfused patients is iron overload. Less common - but serious - reactions more specific to blood transfusion include transfusion-associated graft-versus-host disease and transfusion-associated acute lung injury. Many of these complications of transfusion therapy can be prevented by adhering to well-established practice guidelines. In addition, individuals who administer blood transfusions should recognize these complications in order to be able to quickly provide appropriate treatment.