Siderophore-producing Pantoea ferrattrahens sp. nov. isolated from a clinical specimen and Pantoea ferramans sp. nov. isolated from soil at the bottom of a pond.

Two Gram-negative facultative anaerobes were isolated from a sepsis patient with pancreatic cancer (strain PAGU 2156T ) and soil at the bottom of a pond (strain PAGU 2198T ), respectively. These two strains formed haloes around the colonies on chrome azurol S agar plates, indicating the production of siderophores. Two isolates assigned to the genus Pantoea based on the 16S rRNA gene were differentiated from established species by using polymorphic taxonomies. Phylogenetic analysis using four housekeeping genes (gyrB, rpoB, atpD, and infB) showed that strain PAGU 2156T is closely related to Pantoea cypripedii LMG 2657T (89.9%) or Pantoea septica LMG 5345T (95.7%). Meanwhile, strain PAGU 2198T formed a single clade with Pantoea rodasii DSM 26611T (93.6%) and Pantoea rwandensis DSM 105076T (93.3%). The average nucleotide identity values obtained from the draft genome assembly showed ≤90.2% between strain PAGU 2156T and closely related species and ≤81.5% between strain PAGU 2198T and closely related species. Based on various phenotypes, biochemical properties, and whole-cell fatty acid composition compared with related species, it was concluded that each strain should be classified as a new species of the genus Pantoea. In this manuscript, Pantoea ferrattrahens sp. nov. and Pantoea ferramans sp. nov. with strain PAGU 2156T (=NBRC 115930T = CCUG 76757T ) and strain PAGU 2198T (=NBRC 114265T = CCUG 75151T ) are proposed as each type strain.

[Association of Geriatric Nutritional Risk Index with Adverse Events and Time to Treatment Failure in Malignant Lymphoma Patients Treated with(R-)EPOCH].

To date, there are no reports that examine the relationship between geriatric nutritional risk index(GNRI)at the start of chemotherapy for malignant lymphoma and adverse effects. In this study, we investigated the relationship between GNRI at the start of chemotherapy and the incidence of side effects and time to treatment failure(TTF)in(R-)EPOCH-treated patients with relapsed or refractory malignant lymphoma. A significant difference in the incidence of Grade 3 or higher thrombocytopenia was observed between high and low GNRI groups(p=0.043). The GNRI may be an indicator of hematologic toxicity in malignant lymphoma patients treated with(R-)EPOCH. There was a statistically significant difference in TTF between the high and low GNRI groups(p=0.025), suggesting that nutritional status at the start of(R-)EPOCH may affect treatment continuation.

First case of a renal cyst infection caused by Desulfovibrio: a case report and literature review.

BACKGROUND: Genus Desulfovibrio species is a sulphate-reducing anaerobic gram-negative rod that resides in the human oral cavity and intestinal tract. It was reported as the causative pathogen of bacteraemia and abdominal infections, but not renal cyst infection, and Desulfovibrio fairfieldensis has higher pathogenicity than other Desulfovibrio species. CASE PRESENTATION: A 63-year-old man was on haemodialysis for end-stage renal failure due to autosomal dominant polycystic kidney disease. On admission, he had a persistent high-grade fever, right lumbar back pain, and elevated C-reactive protein levels. His blood and urine cultures were negative. He received ciprofloxacin and meropenem; however, there was no clinical improvement. Contrast-enhanced computed tomography and plain magnetic resonance imaging revealed a haemorrhagic cyst at the upper pole of the right kidney. The lesion was drained. Although the drainage fluid culture was negative, D. fairfieldensis was detected in a renal cyst using a polymerase chain reaction. After the renal cyst drainage, he was treated with oral metronidazole and improved without any relapse. CONCLUSIONS: To the best of our knowledge, this is the first reported case of a renal cyst infection with Desulfovibrio species. D. fairfieldensis is difficult to detect, and polymerase chain reaction tests can detect this bacterium and ensure better management for a successful recovery.

The histone deacetylase inhibitor OBP-801 has in vitro/in vivo anti-neuroblastoma activity.

BACKGROUND: Patients with high-risk neuroblastoma have a poor prognosis; new therapeutic agents are therefore required. We investigated the antitumor effects of OBP-801, a novel histone deacetylase inhibitor, its underlying mechanism, and its potential as a therapeutic agent for patients with neuroblastoma. METHODS: The study included five human neuroblastoma cell lines: IMR32, GOTO, KP-N-RTBM, SK-N-AS, and SH-SY5Y. We investigated cell proliferation, cell cycle status, protein expression patterns, and apoptosis in neuroblastoma cells after OBP-801 treatment in vitro. Cell survival rate and cell cycle were analyzed using the WST-8 assay and flow cytometry, respectively. Apoptosis was detected using annexin V staining, and the expression of apoptosis-related proteins was investigated by western blotting. The antitumor activity of OBP-801 was examined in an in vivo xenograft mouse model. RESULTS: Dose-effect curve analysis showed that the mean half-maximal inhibitory concentration value was 5.5 ± 5.9 nM for the MYCN-amplified cell lines (IMR32, GOTO, and KP-N-RTBM) and 3.1 ± 0.7 nM for the MYCN-nonamplified cell lines (SK-N-AS and SH-SY5Y). OBP-801 inhibited cell proliferation and growth in all the cell lines. It induced G2/M phase arrest through the p21 (CDKN1A) pathway, increasing histone H3 levels and, subsequently, apoptosis in human neuroblastoma cells. OBP-801 suppressed the growth of neuroblastoma cells in the mouse xenograft model. CONCLUSIONS: Overall, OBP-801 induces M-phase arrest and apoptosis in neuroblastoma cells via mitotic catastrophe. Our results indicate that OBP-801 is a promising therapeutic agent with fewer adverse effects for patients with neuroblastoma.

Molecular characteristics of an adhesion molecule containing cholesterol-dependent cytolysin-motif produced by mitis group streptococci.

Streptococcus pseudopneumoniae (SPpn) is a relatively new species closely related to S. pneumoniae (SPn) and S. mitis (SM) belonging to the Mitis group of the genus Streptococcus (MGS). Although genes encoding various pneumococcal virulence factors have been observed in the SPpn genome, the pathogenicity of SPpn against human, including the roles of virulence factor candidates, is still unclear. The present study focused on and characterized a candidate virulence factor previously reported in SPpn with deduced multiple functional domains, such as lipase domain, two lectin domains, and cholesterol-dependent cytolysin-related domain using various recombinant proteins. The gene was found not only in SPpn but also in the strains of SM and SPn. Moreover, the gene product was expressed in the gene-positive strains as secreted and cell-bound forms. The recombinant of gene product showed lipase activity and human cell-binding activity depending on the function of lectin domain(s), but no hemolytic activity. Thus, based on the distribution of the gene within the MGS and its molecular function, the gene product was named mitilectin (MLC) and its contribution to the potential pathogenicity of the MLC-producing strains was investigated. Consequently, the treatment with anti-MLC antibody and the mlc gene-knockout significantly reduced the human cell-binding activity of MLC-producing strains. Therefore, the multifunctional MLC was suggested to be important as an adhesion molecule in considering the potential pathogenicity of the MLC-producing strains belonging to MGS, such as SPpn and SM.

Oncogenic role of HMGA2 in fusion-negative rhabdomyosarcoma cells.

BACKGROUND: Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma. There are two subtypes, fusion gene-positive RMS (FP-RMS) and fusion gene-negative RMS (FN-RMS), depending on the presence of a fusion gene, either PAX3-FOXO1 or PAX7-FOXO1. These fusion genes are thought to be oncogenic drivers of FP-RMS. By contrast, the underlying mechanism of FN-RMS has not been thoroughly investigated. It has recently been shown that HMGA2 is specifically positive in pathological tissue from FN-RMS, but the role of HMGA2 in FN-RMS remains to be clarified. METHODS: In this study, we used FN-RMS cell lines to investigate the function of HMGA2. Gene expression, cell growth, cell cycle, myogenic differentiation, tumor formation in vivo, and cell viability under drug treatment were assessed. RESULTS: We found that HMGA2 was highly expressed in FN-RMS cells compared with FP-RMS cells and that knockdown of HMGA2 in FN-RMS cells inhibited cell growth and induced G1 phase accumulation in the cell cycle and myogenic differentiation. Additionally, we showed using both gain-of-function and loss-of-function assays that HMGA2 was required for tumor formation in vivo. Consistent with these findings, the HMGA2 inhibitor netropsin inhibited the cell growth of FN-RMS. CONCLUSIONS: Our results suggest that HMGA2 has important role in the oncogenicity of FP-RMS and may be a potential therapeutic target in patients with FN-RMS.

Description of four Apiotrichum and two Cutaneotrichosporon species isolated from guano samples from bat-inhabited caves in Japan.

Four new yeast species belonging to the genus Apiotrichum and two new yeast species belonging to Cutaneotrichosporon are described for strains isolated from guano samples from bat-inhabited caves in Japan. In 2005, we reported these isolates as Trichosporon species based on sequence analyses of the D1/D2 domain of large subunit (LSU) rRNA genes according to available basidiomycetous yeast classification criteria; however, to date, they have not been officially published as new species with descriptions. Their phylogenetic positions have been reanalysed based on comparison of internal transcribed spacer (ITS) region sequences (including the 5.8S rRNA gene) and the D1/D2 domain of the LSU rRNA gene with those of known species; we confirmed clear separation from previously described species. Physiological and biochemical properties of the isolates also suggest their distinctiveness. Therefore, we describe Apiotrichum akiyoshidainum (holotype JCM 12595T), Apiotrichum chiropterorum (JCM 12594T), Apiotrichum coprophilum (JCM 12596T), Apiotrichum otae (JCM 12593T), Cutaneotrichosporon cavernicola (JCM 12590T) and Cutaneotrichosporon middelhovenii (JCM 12592T) as new species. C. cavernicola showed particularly distinctive morphology including large inflated anomalous cells on the hyphae and germination from the cells, although clear clamp connections on the hyphae were not confirmed. Further study is needed to elucidate the morph of this species.

Pulmonary infection due to fluoroquinolone-resistant Mycolicibacterium fortuitum: a case report.

BACKGROUND: Mycolicibacterium fortuitum is a species of the rapidly growing mycobacteria that can cause pulmonary infection. It is susceptible to multiple antibiotics both in vitro and in clinical practice, so that any combination of susceptible drugs is effective. However, we encountered a case of infection due to fluoroquinolone-resistant M. fortuitum. In this study, we report the case and describe the mechanism of resistance. CASE PRESENTATION: A 65-year-old man with a history of total gastrectomy and immunosuppressant treatment for rheumatoid arthritis developed a recurrence of pulmonary infection caused by M. fortuitum. He was treated with clarithromycin and levofloxacin as a first-line treatment, based on the favorable susceptibility at that time. After recurrence, a high minimum inhibitory concentration to fluoroquinolones was detected. DNA sequencing of the pathogen showed the substitution of serine for tryptophan at residue 83 in the gyrA gene. He was successfully treated with a combination of other antibiotics. CONCLUSION: This is the first report on the treatment of fluoroquinolone-resistant M. fortuitum and investigation of the mechanism of resistance. We suggest that the susceptibility test remains effective for determining the next line of treatment after a pathogen has acquired resistance, and resistance to fluoroquinolones in M. fortuitum can be attributed to a single change of amino acid.

Mutations in the RAS pathway as potential precision medicine targets in treatment of rhabdomyosarcoma.

Precision medicine strategies for treating rhabdomyosarcoma (RMS), a childhood malignancy, have not been developed. We examined the effect of CH5126766, a potent selective dual RAF/MEK inhibitor, on RMS cell lines. Among the eleven cell lines studied, one NRAS and two HRAS mutated cell lines were detected. CH5126766 inhibited the proliferation and growth in all of the RAS-mutated RMS cell lines, while it induced G1 cell cycle arrest in two of them. G1 cell cycle arrest was accompanied by p21 up-regulation and RB dephosphorylation. CH5126766 also suppressed the in vivo growth of RAS-mutated RMS tumor, and the mice showed improved survival. Thus, our results demonstrate that CH5126766 is an effective RAF/MEK inhibitor in RAS-mutated RMS. This study not only shows that in RMS, mutations in the RAS pathway can be a target for precision medicine, but also demonstrates that the evaluation of the gene mutation status is important in childhood malignancies.

Spodiobacter cordis gen. nov. sp. nov., a member of the family Flavobacteriaceae isolated from patients with infective endocarditis.

Two gram-negative, catalase-negative, oxidase-positive strains (PAGU 1467T and PAGU 1468) isolated from patients with infective endocarditis were investigated to determine their taxonomic status. 16S rRNA gene sequence analysis indicated that the two strains were members of the Bergeyella-Chryseobacterium-Riemerella branch of the family Flavobacteriaceae. Strains PAGU 1467T and PAGU 1468 were highly related to each other (98.8% 16S rRNA gene sequence similarity). Phylogenetically closely-related species to PAGU 1467T comprised Bergeyella zoohelcum (95.0% 16S rRNA gene sequence similarity), Riemerella anatipestifer (94.3%) and Cloacibacterium normanense (94.3%). The major fatty acids of the two isolates were iso-C15:0 , iso-C17:0 3-OH and iso-C15:0 3-OH. The presence of C16:0 3-OH and iso-C15:0 2-OH allowed these isolates to be distinguished from B. zoohelcum. Menaquinone MK-6 was the only respiratory quinone in these organisms; this is a consistent characteristic of the family Flavobacteriaceae. The guanine-plus-cytosine content of the genomic DNA was 42.0%, which is higher than that of other close phylogenetic relatives. On the basis of their phenotypic properties and genetic distinctiveness, isolates PAGU 1467T and PAGU 1468 were classified within the novel genus Spodiobacter, as Spodiobacter cordis gen. nov., sp. nov., which is also the type species. The type strain of S. cordis is PAGU 1467T ( = CCUG 65564T = NBRC 109998T ).

A prospective evaluation of liquid biopsy for detecting MYCN amplification in neuroblastoma patients.

BACKGROUND: Our previous study reported a method for determining MYCN gene amplification (MNA) status using cell-free DNA in serum. We prospectively analyzed the serum MNA status using sera obtained before the initial diagnosis from patients with neuroblastoma and evaluated the utility of this method. METHODS: Eighty patients were enrolled in the study. The serum MYCN/NAGK ratio was assessed for all cases. RESULTS: Fifteen cases showed serum MNA, while 65 did not. Of the 80 total patients, tumor samples for a genetic analysis were not obtained from 27 due to the patients' condition or other reasons. For the 43 of 80 cases that had both serum and tumor samples analyzed, the serum-based MNA status matched to tumor-based MNA status (P < 0.001). The sensitivity and the specificity were 100%, respectively. Seven of 15 cases who diagnosed as MNA by serum-based MNA status were <18 months of age, and tumor samples were not obtained from 4 of these cases. Based on the serum MNA status, these cases were able to start treatment immediately. The 4-year event-free survival rates of cases with and without MNA in sera were 37.5% and 84.8%, respectively (P < 0.001). CONCLUSION: The serum-based MNA status was useful for precisely predicting the MNA status in tumor and it has clinical benefits for predicting risk stratification in patients for whom obtaining tumor samples is difficult.

Purpura fulminans with Lemierre's syndrome caused by Gemella bergeri and Eikenella corrodens: a case report.

BACKGROUND: Gemella bergeri is one of the nine species of the genus Gemella and is relatively difficult to identify. We herein describe the first case of septic shock due to a Gemella bergeri coinfection with Eikenella corrodens. CASE PRESENTATION: A 44-year-old Asian man with a medical history of IgG4-related ophthalmic disease who was prescribed corticosteroids (prednisolone) presented to our hospital with dyspnea. On arrival, he was in shock, and a purpuric eruption was noted on both legs. Contrast enhanced computed tomography showed fluid retention at the right maxillary sinus, left lung ground glass opacity, and bilateral lung irregular opacities without cavitation. Owing to suspected septic shock, fluid resuscitation and a high dose of vasopressors were started. In addition, meropenem, clindamycin, and vancomycin were administered. Repeat computed tomography confirmed left internal jugular and vertebral vein thrombosis. Following this, the patient was diagnosed with Lemierre's syndrome. Furthermore, he went into shock again on day 6 of hospitalization. Additional soft tissue infections were suspected; therefore, bilateral below the knee amputations were performed for source control. Cultures of the exudates from skin lesions and histopathological samples did not identify any pathogens, and histopathological findings showed arterial thrombosis; therefore it was concluded that the second time shock was associated with purpura fulminans. Following this, his general status improved. He was transferred to another hospital for rehabilitation. The blood culture isolates were identified as Gemella bergeri and Eikenella corrodens. Gemella bergeri was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry and confirmed by 16S rRNA gene sequencing later. The primary focus of the infection was thought to be in the right maxillary sinus, because the resolution of the fluid retention was confirmed by repeat computed tomography. CONCLUSIONS: Gemella bergeri can be the causative pathogen of septic shock. If this pathogen cannot be identified manually or through commercial phenotypic methods, 16S rRNA gene sequencing should be considered.

Fatal Fournier's gangrene caused by Clostridium ramosum in a patient with central diabetes insipidus and insulin-dependent diabetes mellitus: a case report.

BACKGROUND: Clostridium ramosum is a generally non-pathogenic enteric anaerobe, and Fournier's gangrene is a rare necrotizing soft tissue infection with male predisposition affecting the perineum and the genital area. We report, to our knowledge, the first case of Fournier's gangrene caused by C. ramosum in a female patient with multiple underlying conditions. CASE PRESENTATION: A 44-year-old woman with a 6-year history of insulin-dependent diabetes mellitus after total pancreatectomy and an 11-year history of central diabetes insipidus developed a pain in the genital area after a month of urinary catheter use. The lower abdominal pain worsened gradually over 2 weeks, and the pain, general fatigue, and loss of appetite prompted the patient's hospital admission. As she had severe edema in her pelvic and bilateral femoral areas, ceftriaxone was started empirically after collecting two sets of blood cultures. On hospital day 2, CT examination revealed the presence of necrotizing faciitis in the genital and pelvic areas, and the antibiotics were changed to a combination of meropenem, vancomycin, and clindamycin. Gram-positive cocci and gram-positive rods were isolated from blood cultures, which were finally identified as Streptococcus constellatus and C. ramosum using superoxide dismutase and 16S rDNA sequencing. An emergent surgery was performed on hospital day 2 to remove the affected tissue. Despite undergoing debridement and receiving combined antimicrobial chemotherapies, the patient's clinical improvement remained limited. The patient's condition continued to deteriorate, and she eventually died on hospital day 8. In the present case, the underlying diabetes mellitus, urinary incontinence due to central diabetes insipidus, undernutrition, and edema served as the predisposing conditions. CONCLUSIONS: C. ramosum is a potentially opportunistic pathogen among immunosuppressed persons and a rare cause of necrotizing fasciitis.

Breakthrough Candida guilliermondii (Meyerozyma guilliermondii) fungemia after cord blood transplantation for extranodal NK-cell lymphoma with azole prophylaxis.

Fluconazole (FLCZ) is an azole antifungal agent and it has shown excellent clinical activities in suppressing fungemia with Candida albicans after hematopoietic stem cell transplantation. Increased administration of prophylactic FLCZ seems to have given rise to the relatively higher incidence of more resistant Candida non-albicans infection. We present a case with a rare breakthrough fungemia with C. guilliermondii after cord blood transplantation for Extranodal NK cell Lymphoma, nasal type (ENKL), during antifungal prophylaxis with FLCZ. High level of caution is needed for the breakthrough, especially after long-term azole administration.

Purulent lymphadenitis caused by Staphylococcus argenteus, representing the first Japanese case of Staphylococcus argenteus (multilocus sequence type 2250) infection in a 12-year-old boy.

Staphylococcus argenteus is a novel species separated from a strain of coagulase-positive, non-pigmented S. aureus. Although S. argenteus has been reported to occur globally, multilocus sequence type (ST) 2250 is mainly found in Northeastern Thailand. Because conventional biochemical testing misidentifies this pathogen as S. aureus, multilocus sequence typing (MLST) or nucA sequencing is recommended to distinguish between S. argenteus and S. auereus. The patient was a previously healthy 12-year-old boy who was admitted because of right inguinal lymphadenitis and cellulitis. Although intravenous cefazolin was administered, his lymphadenitis worsened and formed an abscess on day 6 of hospitalization. Incision and drainage were performed on day 7 of hospitalization. Cefazolin was changed to oral cefaclor, and the patient was successfully treated over a period of 5 weeks. No recurrence was observed throughout 12-months of follow-up. He had a history of right axillary lymph node abscess 2 months before this admission, which was successfully treated with incision, drainage, and antibiotic therapy. He has lived in Japan since birth and never traveled abroad. He had no opportunity to interact with foreigners. His immune function, especially neutrophil function, was tested and we did not find any dysfunction. First, methicillin-sensitive S. aureus was misidentified from the abscess culture. Subsequently, the causative agent was re-identified as S. argenteus ST2250 based on MLST. To our knowledge, this is the first case of S. argenteus ST2250 infection in Japan. This pathogen should be taken into consideration in the diagnosis if the patient has atypical non-pigmented S. aureus.

Defining the taxonomic status of Streptococcus suis serotype 33: the proposal for Streptococcus ruminantium sp. nov.

To clarify the taxonomic classification of Streptococcus suis serotype 33, we performed biochemical and molecular genetic analyses using isolates (GUT-183, GUT-184, GUT-185, GUT-186, GUT-187T, GUT-188, GUT-189, GUT-190, GUT-191, GUT-192 and GUT-193) from bovine endocarditis. A comparative sequence analysis showed 99.2-100 % sequence similarity among the reference strain of S. suis serotype 33 and our isolates for the 16S rRNA gene. These similarities were higher than those between the isolate GUT-187T and S. suis and other streptococci. Comparison of sodA genes also showed high degrees of similarities among the reference strain of S. suis serotype 33 and our isolates (99.7-100 %), which were higher than those between the GUT-187T and S. suis and other streptococci. DNA-DNA relatedness among three isolates (GUT-186, GUT-187T, the reference strain of S. suis serotype 33) was over 76.7 %. In contrast, the relatedness between GUT-187T and the other streptococcal species (S. suis, Streptococcus parasuis, Streptococcus acidominimus and Streptococcus porci) was 8.4-24.9 %. Phylogenetic analyses showed that the isolates did not affiliate closely to any known species of the genus Streptococcus. Moreover, GUT-187T could be distinguished from S. suis and other closely related species of genus Streptococcus using biochemical tests. On the basis of the phenotypic and molecular genetic data, we propose that the isolates of S. suis serotype 33 should be classified into the genus Streptococcus, Streptococcus ruminantium sp. nov. with the type strain GUT-187T (=DSM 104980T=JCM 31869T).

The first case report of infective endocarditis caused by Gemella taiwanensis.

Gemella is a facultative anaerobic Gram-positive coccus and a rare cause of infective endocarditis (IE). Gram staining may eventually misidentify the organism, which tends to easily decolorize and manifest as either Gram-negative or Gram-variable. Commercial biochemical tests are often used to identify Gemella, but the methods they employ sometimes lack accuracy. A 52-year-old woman was diagnosed with Gemella taiwanensis IE after initial identification of the pathogen as Gemella haemolysans using biochemical tests combined with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). She was treated successfully with penicillin, gentamicin, and mitral valve replacement. To our knowledge, this is the first case of IE confirmed by 16S rRNA gene and groEL sequencing to have been caused by G. taiwanensis. The accurate diagnosis of rare or difficult-to-identify pathogens is a major challenge for clinical microbiological laboratories. The concurrent use of molecular methods could lead to the recognition of new or different pathogens.

Cell-cycle dependent expression of a translocation-mediated fusion oncogene mediates checkpoint adaptation in rhabdomyosarcoma.

Rhabdomyosarcoma is the most commonly occurring soft-tissue sarcoma in childhood. Most rhabdomyosarcoma falls into one of two biologically distinct subgroups represented by alveolar or embryonal histology. The alveolar subtype harbors a translocation-mediated PAX3:FOXO1A fusion gene and has an extremely poor prognosis. However, tumor cells have heterogeneous expression for the fusion gene. Using a conditional genetic mouse model as well as human tumor cell lines, we show that that Pax3:Foxo1a expression is enriched in G2 and triggers a transcriptional program conducive to checkpoint adaptation under stress conditions such as irradiation in vitro and in vivo. Pax3:Foxo1a also tolerizes tumor cells to clinically-established chemotherapy agents and emerging molecularly-targeted agents. Thus, the surprisingly dynamic regulation of the Pax3:Foxo1a locus is a paradigm that has important implications for the way in which oncogenes are modeled in cancer cells.

Potential Impact of Rapid Blood Culture Testing for Gram-Positive Bacteremia in Japan with the Verigene Gram-Positive Blood Culture Test.

Background. Early detection of Gram-positive bacteremia and timely appropriate antimicrobial therapy are required for decreasing patient mortality. The purpose of our study was to evaluate the performance of the Verigene Gram-positive blood culture assay (BC-GP) in two special healthcare settings and determine the potential impact of rapid blood culture testing for Gram-positive bacteremia within the Japanese healthcare delivery system. Furthermore, the study included simulated blood cultures, which included a library of well-characterized methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) isolates reflecting different geographical regions in Japan. Methods. A total 347 BC-GP assays were performed on clinical and simulated blood cultures. BC-GP results were compared to results obtained by reference methods for genus/species identification and detection of resistance genes using molecular and MALDI-TOF MS methodologies. Results. For identification and detection of resistance genes at two clinical sites and simulated blood cultures, overall concordance of BC-GP with reference methods was 327/347 (94%). The time for identification and antimicrobial resistance detection by BC-GP was significantly shorter compared to routine testing especially at the cardiology hospital, which does not offer clinical microbiology services on weekends and holidays. Conclusion. BC-GP generated accurate identification and detection of resistance markers compared with routine laboratory methods for Gram-positive organisms in specialized clinical settings providing more rapid results than current routine testing.

The first cases of human bacteremia caused by Acinetobacter seifertii in Japan.

Acinetobacter seifertii, a novel species of Acinetobacter, was first reported in 2015. A. seifertii strains were isolated from human clinical specimens (blood, respiratory tract, and ulcer) and hospital environments. Here, we report the first cases of bacteremia caused by A. seifertii in patients with catheter-related bloodstream infection in Japan. The patients favorably recovered, without any complications, after removal of the peripheral intravenous catheters and administration of antibiotics. The pathogens were initially identified as Acinetobacter baumannii, using phenotypic methods and the MicroScan Walkaway System; however, rpoB gene sequence analysis indicated 99.54% similarity to A. seifertii. Moreover, antimicrobial susceptibility testing revealed that one of the strains was not susceptible to gentamicin and ceftazidime. Our report shows that Acinetobacter species other than A. baumannii can also cause nosocomial infections and that accurate methods for the identification of causative agents should be developed.