Evolution, Incidence, and Susceptibility of Bacterial Bloodstream Isolates from 519 Bone Marrow Transplant Patients

Abstract

Bacteria remain an important cause of infection in bone marrow transplants. To examine shifts in the etiology and susceptibility of bacterial isolates from transplants, we reviewed the incidence and susceptibility of blood isolates during a 7-year period. The infection rate fell dramatically during this time. Gram-positive organisms were isolated more often than gram-negative organisms, but the trend is reversing. Streptococci surpassed staphylococci for 5 years as the leading pathogen. Increasing resistance to penicillin, ciprofloxacin, and imipenem was noted in Streptococcus species. With the exception of type 1 beta-lactamase-producing bacteria and Pseudomonas aeruginosa, gram-negative isolates remained overall susceptible to ceftazidime. Increased antibiotic prophylaxis coincided with the reduction in percentage of infected patients and increase in resistance to beta-lactam antibiotics. Mortality attributed to bacteremia was low except for infections caused by P. aeruginosa and the Enterobacter, Serratia, Citrobacter group. There was no mortality attributable to gram-positive organisms such as Staphylococcus aureus and viridans streptococci.

Etiology, clinical features and outcomes of pre-engraftment and post-engraftment bloodstream infection in hematopoietic SCT recipients

“…This finding is in line with other studies that have found a higher risk of BSI in this specific group of transplant recipients. 3,7 During the pre-engraftment period, we identified the presence of neutropenia, a central venous catheter and severe mucositis as important risk factors for BSI. During the pre-engraftment phase it is likely that mucosal damage allows bacteria to enter the bloodstream and the lack of neutrophils hampers their effective clearance, thus leading to BSI.…”

“…One trial showed similar antibody responses with vaccination started at 3 months (early) and 9 months (late) post transplant. 7 Thus, early vaccination may be preferred as it may protect against both late and early pneumococcal disease. It should be noted that early vaccination may not prime for a PPSV23 boost as efficiently as late vaccination.…”

“…Nevertheless, the differences between infections occurring pre-and post-engraftment have not been fully described. 2,6 Most published articles regarding BSI in HSCT recipients are retrospective and/or focus on subjects who underwent transplantation in the 1990 s. 3,[5][6][7][8][9][10] Since then, there have been changes in the care of HSCT recipients, such as the introduction of different types of donors, different immunosuppression, conditioning chemotherapy including reduced-intensity regimens, and so on. Furthermore, changes in the etiology of BSI in cancer patients have recently been described.…”

Umbilical cord blood transplantation: Basic biology and clinical challenges to immune reconstitution

“…Immune reconstitution of T-and B-cell compartments following allogeneic transplantation may require as long as 12-24 months. The slow process of immune reconstitution together with post-engraftment immunosuppression creates an immunologic environment whereby the host is susceptible to opportunistic infections [54][55][56] as well as virally induced malignancies [57,58]. Recipients of unrelated donor or HLA non-identical transplants appear to have a higher rate of infectious complications than recipients of matched sibling allogeneic grafts [59][60][61].…”

High Levels of Hand-Hygiene Compliance Are a Worthwhile Pursuit

“…Each CLABSI puts patients at greater risk of complications including: sepsis, endocarditis, multidrug-resistant (MDR) bacteria, thrombosis and malnutrition which may lead to more hospital stays, increased costs of care, and decreased quality of life. 2,3 Additionally, most bloodstream infections require catheter replacement for optimal management. 4 Ethanol lock therapy (ELT) is a proposed method to reduce CLABSIs requiring hospitalizations and associated line replacements by preventing catheters from becoming colonized.…”