Kidney damage relates to agonal bacteremia: a single-center retrospective study.

BACKGROUND: Agonal bacteremia, diagnosed with postmortem positive blood culture results, is considered a possible contributing factor to death. We hypothesized that some premortem organ damage, such as kidney damage, can enhance agonal bacteremia. METHODS: We performed a postmortem blood and alveolar fluid culture study in 30 cadavers and evaluated the relationship between blood culture results and clinical parameters, including organ damage (brain, heart, lung, kidney, liver and gastrointestinal tract). RESULTS: A total of 23 cases (76.7%) were positive for blood culture; the number of cultured species was one in 12 cases, two in 7 cases, and three in 4 cases. The ratio of agonal bacteremia was significantly higher in patients with heart damage (100%, n = 13) and those with kidney damage (end-stage kidney damage, acute kidney injury, obstructive kidney failure, or metastatic kidney tumours) (100%, n = 13). The mean number of cultured species was 0.67 ± 0.98 in heart or kidney damage, 1.40 ± 0.55 in heart damage only, 1.40 ± 0.55 in kidney damage only, and 2.00 ± 0.93 in heart and kidney damage. As the number of damaged organs increased (0 organs, no heart/kidney damage; 1 organ, heart or kidney damage; and 2 organs, heart and kidney damage), the mean number of cultured species increased significantly (p for trend = 0.001964). CONCLUSION: Premortem kidney damage relates to agonal bacteremia.

Examination of conditions for regular internal quality control in identification of microorganisms using MALDI-TOF MS.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was approved for medical use in 2011, and is currently used as a rapid, accurate and low-cost technique for bacterial identification. Microbiological testing and internal accuracy control in Japan are mainly implemented in accordance with the standards of the Clinical and Laboratory Standards Institute (CLSI). However, few facilities perform internal accuracy control of bacterial identification by MALDI-TOF MS. Therefore, we examined the procedures for internal accuracy control of bacterial identification using MALDI-TOF MS in daily work at clinical laboratories in the seven hospitals.

[Evaluation of cardiac dysfunction after herceptin treatment in patients with metastatic breast cancer by echocardiography].

Herceptin (Trastuzumab) is a humanized recombinant monoclonal antibody that binds the extracellular domain of the human epidermal growth factor receptor 2 (HER2) and is used in the treatment of patients with HER2 overexpressing metastatic breast cancer. Treatment with Herceptin is generally well tolerated. At times, however, it exerts cardiac toxicity especially when used in combination with anthracyclines. We evaluated cardiac function before and after Herceptin treatment in nine patients with metastatic breast cancer by echocardiography, measuring ejection fraction (EF) and deceleration time (DcT). EF was significantly reduced after treatment(P<0.05). Although the present study failed to show significant changes in DcT, definite diastolic disturbance of the left ventricle did occur in a couple of patients. We conclude that cardiac dysfunction may be a common side effect of Herceptin even in early stages of treatment and that echocardiography will be a useful means of monitoring cardiac function in these patients.

Rapid identification of Streptococcus intermedius by PCR with the ily gene as a species marker gene.

Streptococcus intermedius belongs to the anginosus group of streptococci (AGS) and is associated with endogenous infections leading to abscesses in the oral cavity and at deepseated sites, such as the brain and liver. Two other species, S. anginosus and S. constellatus, and some presently unnamed taxa, are also classified as AGS. Recently, S. constellatus subsp. pharyngis, a new subspecies with biochemical characteristics similar to S. intermedius, was described with the potential for causing confusion when trying to identify isolates of these two species routinely with commercial identification kits, such as Rapid ID32 Strep and Fluo-Card Milleri. To correctly identify S. intermedius, this study attempted to develop an accurate PCR identification system with the ily gene as a species marker. This approach relies on amplification of an 819-bp fragment of the ily gene and its 3'-flanking region and is shown here to be specific for S. intermedius strains among all other streptococcal species. Moreover, this PCR system was applicable in direct rapid PCR with whole bacterial cells and TaKaRa Z-Taq (TaKaRa), a highly efficient DNA polymerase, as the template and DNA amplification enzyme, respectively.

The human-specific action of intermedilysin, a homolog of streptolysin O, is dictated by domain 4 of the protein.

Intermedilysin is a pore-forming cytolysin belonging to the streptolysin O gene family known as the 'Cholesterol-binding/dependent cytolysins' and is unique within the family in that it is highly humanspecific. This specificity suggests interaction with a component of human cells other than cholesterol, the proposed receptor for the other toxins of the gene family. Indeed, intermedilysin showed no significant degree of affinity to free or liposome-embedded cholesterol. Characterization of intermedilysin undecapeptide mutants revealed that this lack of affinity to cholesterol was a result of the substitutions of intermedilysin in this region. Absorption assays with erythrocyte membranes from various animals, competitive inhibition with domain 4 of intermedilysin and liposome-binding assays of streptolysin O and intermedilysin indicated that cell membrane binding is the human-specific step of intermedilysin action, that the host cell membrane-binding site is located within domain 4 in common with other members of the family and that the receptor for this toxin is not cholesterol. The species specificity of undecapeptide mutants of intermedilysin and streptolysin O and chimeric mutants between intermedilysin and streptolysin O, and intermedilysin and pneumolysin indicated that domain 4 of intermedilysin determines the human-specific action step and the cell-binding site of domain 4 lies within the 56 amino acids of the C-terminal, excluding the undecapeptide region.