Sandra Ramirez-Arcos

Canadian experience with detection of bacterial contamination in apheresis platelets

BACKGROUND: In Canada, both blood suppliers, Héma‐Québec (HQ) and Canadian Blood Services (CBS), implemented bacterial testing in apheresis platelets (PLTs) with an automated microbial detection system (BacT/ALERT, bioMérieux).

Bacterial contamination in platelets: incremental improvements drive down but do not eliminate risk

BACKGROUND: Bacterial contamination of platelet components (PCs) remains an important cause of transfusion‐associated infectious risk. In 2004, Canadian Blood Services (CBS) implemented bacterial testing of PCs using the BacT/ALERT 3D system (bioMérieux). This system has been validated and implemented and continuous monitoring of culture rates allows gathering of data regarding true and false positives as well as false negatives.

Detection of bacterial contamination of platelet concentrates.

R. N. I. Pietersz, C. P. Engelfriet, H. W. Reesink, E. M. Wood, S. Winzar, A. J. Keller, J. T. Wilson, G. Henn, W. R. Mayr, S. Ramírez-Arcos, M. Goldman, J. Georgsen, P. Morel, P. Herve, G. Andeu, A. Assal, E. Seifried, M. Schmidt, M. Foley, C. Doherty, P. Coakley, A. Salami, E. Cadden, W. G. Murphy, M. Satake, D. de Korte, V. Bosnes, J. Kjeldsen-Kragh, C. McDonald, M. E. Brecher, R. Yomtovian & J. P. AuBuchon

Staphylococcus epidermidis forms biofilms under simulated platelet storage conditions

BACKGROUND: Staphylococcus epidermidis grows slowly in platelet (PLT) preparations compared to other bacteria, presenting the possibility of missed detection by routine screening. S. epidermidis is a leading cause of nosocomial sepsis, with virulence residing in its ability to establish chronic infections through production of slime layers, or biofilms, on biomedical devices. This study aims to establish biofilm formation (BF) as a mode of growth by S. epidermidis in PLT preparations.

Bacterial contamination in platelet concentrates

R. N. I. Pietersz, H. W. Reesink, S. Panzer, S. Oknaian, S. Kuperman, C. Gabriel, A. Rapaille, M. Lambermont, V. Deneys,D. Sondag, S. Ramirez-Arcos, M. Goldman, G. Delage, F. Bernier, M. Germain, T. Vuk, J. Georgsen, P. Morel, C. Naegelen,L. Bardiaux, J.-P. Cazenave, J. Dreier, T. Vollmer, C. Knabbe, E. Seifried, K. Hourfar, C. K. Lin, M. Spreafico, L. Raffaele,A. Berzuini, D. Prati, M. Satake, D. de Korte, P. F. van der Meer, J. L. Kerkhoffs, L. Blanco, J. Kjeldsen-Kragh,A.-M. Svard-Nilsson, C. P. McDonald, I. Symonds, R. Moule, S. Brailsford, R. Yomtovian & M. R. JacobsSeptic reactions after transfusion, particularly of plateletconcentrates, still occur and belong to the most serioustransfusion reactions. From a previous InternationalForum [1] on the subject, it could be concluded that inpart of the countries that participated in the forum, plate-let concentrates (PCs) were tested for bacterial contamina-tion and that culture-based methods, particularly theBacT/Alert system, were used.In recent years, several rapid bacterial detection meth-ods, such as surrogate measurements of the pH or glu-cose, the detection of bacteria with a scan system orPCR tests that detect bacterial RNA, have been devel-oped. These tests can either be performed immediatelyprior to transfusion of the PC or at a variety of testmoments at which culture and release tests are com-bined.Pathogen inactivation (PI) methods also affect bacterialcontamination of PCs. In 2007 [1], in some countries, theIntercept method of PI of PCs was implemented insteadof bacterial screening.It seemed of interest to evaluate the present state ofthe art of this subject. In order to obtain the desiredinformation, the following questions were sent to expertsin the field.Question 1: How long do you store PC and is there adifference between whole-blood-derived PC and apheresisPC? Which method of preparation do you use for whole-blood-derived PC? Are PCs leuco-reduced?Question 2: Do you use a culture method to detect bac-terial contamination of PC? If so,

Skin disinfection methods: prospective evaluation and postimplementation results

BACKGROUND: Optimal skin disinfection ensures blood safety. In this study, efficacies of the two‐step skin disinfection methods used at Canadian Blood Services (CBS) and two one‐step methods produced by different manufacturers were compared.

Assessment of biofilm‐forming ability of coagulase‐negative staphylococci isolated from contaminated platelet preparations in Canada

BACKGROUND Coagulase-negative staphylococci (CoNS) are the most prevalent bacterial contaminants of platelet (PLT) preparations and have been implicated in adverse transfusion reactions worldwide. The most frequently identified contaminant is Staphylococcus epidermidis, which is noted for its ability to maintain chronic hospital-acquired infections by forming biofilms as a chief virulence mechanism. STUDY DESIGN AND METHODS Strains of S. epidermidis isolated from contaminated PLT preparations in Canada were distinguished via gene-specific polymerase chain reaction (PCR) with divIVA as a marker. Biofilm-forming ability was assessed by the presence of the gene icaD, slime production on Congo red agar, and biofilm formation on polystyrene surfaces. Production of polysaccharide intercellular adhesin (PIA) was resolved by immunofluorescence. RESULTS Eight of the 13 (62%) CoNS isolates under study were identified as S. epidermidis. Of these, four strains (50%) were classified as strong biofilm producers. Three of the four biofilm-positive strains (75%) produced slime, harbored the icaD gene, and had positive expression of PIA. CONCLUSIONS Despite the presumable commensal origin of the CoNS isolates, a large proportion of S. epidermidis strains demonstrated a potential for enhanced virulence. Identification of contaminant staphylococci as biofilm producers is thus relevant and informative with regard to treatment approach in the circumstance of inadvertent infection of a PLT recipient.

Establishment of the first International Repository for Transfusion‐Relevant Bacteria Reference Strains: ISBT Working Party Transfusion‐Transmitted Infectious Diseases (WP‐TTID), Subgroup on Bacteria

Background  Bacterial contamination of platelet concentrates (PCs) still remains a significant problem in transfusion with potential important clinical consequences, including death. The International Society of Blood Transfusion Working Party on Transfusion‐Transmitted Infectious Diseases, Subgroup on Bacteria, organised an international study on Transfusion‐Relevant Bacteria References to be used as a tool for development, validation and comparison of both bacterial screening and pathogen reduction methods.

Serratia marcescens strains implicated in adverse transfusion reactions form biofilms in platelet concentrates and demonstrate reduced detection by automated culture.

Background and Objectives  Serratia marcescens is a Gram‐negative bacterium that has been implicated in adverse transfusion reactions associated with contaminated platelet concentrates. The aim of this study was to investigate whether the ability of S. marcescens to form surface‐attached aggregates (biofilms) could account for contaminated platelet units being missed during screening by the BacT/ALERT automated culture system.

Effect of platelet additive solution on bacterial dynamics and their influence on platelet quality in stored platelet concentrates

BACKGROUND: Platelet additive solutions (PASs) are an alternative to plasma for the storage of platelet concentrates (PCs). However, little is known about the effect of PAS on the growth dynamics of contaminant bacteria. Conversely, there have been no studies on the influence of bacteria on platelet (PLT) quality indicators when suspended in PAS.