Evaluation of the pharmacokinetics of liposomal amphotericin B and analysis of the relationship between pharmacokinetics, efficacy and safety in patients with hematological diseases

INTRODUCTION

This study aimed to identify factors responsible for changes in blood concentrations of a liposomal formulation of amphotericin B (AMPH-B, L-AMB) and analyze the relationships between blood concentrations and efficacy or toxicity.

METHODS

L-AMB was administered to 30 patients being treated for hematological diseases. AMPH-B plasma concentrations were determined right before the initiation (Cmin) and at the end (Cmax) of infusion on at least 1 day, beginning on Day 3 of L-AMB treatment. The relationships of Cmin divided by dose (C/D ratio) to body weight, age, hepatic function, renal function, serum albumin, C-reactive protein (CRP), response, hypokalemia, and renal impairment were evaluated.

RESULTS

C/D ratio was not correlated with age, hepatic function, renal function, or serum albumin. Body weight adjusted C/D ratio was negatively correlated with CRP. Cmax and Cmin were compared between responders and non-responders, those with or without hypokalemia, and those with or without renal impairment. A higher Cmax in patients with hypokalemia was the only significant difference seen.

CONCLUSIONS

The negative correlation between CRP and plasma concentrations was likely caused by higher distribution of L-AMB from the blood to infected tissue in patients with a greater degree of infection, with a resulting decrease in plasma concentrations. AMPH-B plasma concentrations were not related to response. Higher Cmax of AMPH-B were observed in patients with hypokalemia, but no relationship between plasma concentration and renal toxicity was observed, suggesting that AMPH-B plasma concentrations appear to be minimally related to PD when used as L-AMB.

Long-term lymphocyte subset number reconstitution is unique but comparable between umbilical cord blood and unrelated bone marrow transplantation

The number of umbilical cord blood transplantation (U-CBT) procedures has been growing annually, but little research has been done on long-term immune recovery after U-CBT. Infection risk is high in U-CBT recipients, and this can be partially attributed to immature immunocompetent cells in umbilical cord blood. In this study, we analyzed lymphocyte subset (LST) number to determine the long-term recovery timeline. We included 36 U-CBT and 10 unrelated bone marrow transplantation (U-BMT) recipients who survived more than 2 years after transplantation, and followed them for up to 10 years post-transplant. Recovery kinetics in the early phase post-transplant was different for each LST. Recovery of CD19+ B cells was faster after U-CBT than after U-BMT in the first 5 years after transplantation. Although CD4+ T cells increased in the first several months after U-CBT, long-term cell count recovery was impaired in approximately 20% of patients. Thus, although the LST recovery pattern after U-CBT was unique, LST number recovery was statistically comparable between U-CBT and U-BMT past 5 years post-transplantation.

[Fulminant Clostridioides difficile infection during treatment with FLT3 inhibitor for acute myeloid leukemia]

An 80-year-old man with FLT3-TKD mutation-positive acute myeloid leukemia (AML) relapsed during consolidation therapy with venetoclax/azacitidine and was started on gilteritinib as salvage therapy. On the day after treatment initiation, febrile neutropenia was observed, but the fever resolved promptly after initiation of antimicrobial therapy. On the fifth day after completion of antimicrobial therapy, the patient experienced fever and watery diarrhea over 10 times a day, and a diagnosis of Clostridioides difficile infection (CDI) was made based on stool examination. The patient was treated with intravenous metronidazole, but renal dysfunction, hypotension, and hypoxemia developed, and a CT scan showed pleural and intraperitoneal effusion, significant intestinal wall thickening, and intestinal dilatation. Fidaxomicin was started under general monitoring in the intensive care unit and response was achieved. The patient was discharged from the intensive care unit on the 18th day after the onset of CDI. We report this case not only due to the rarity of fulminant CDI during AML treatment, but also because it is a valuable example of effective treatment of fulminant CDI with fidaxomicin.

Helicobacter fennelliae Localization to Diffuse Areas of Human Intestine, Japan

The site of enterohepatic Helicobacter colonization/infection in humans is still unknown. We report microbiologically and histopathologically confirmed H. fennelliae localization in the large intestine in an immunocompromised patient in Japan. This case contributes to better understanding of the life cycle of enterohepatic Helicobacter species.

A case of mild encephalitis associated with COVID-19

We report a case of mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) in a 31-year-old man. He had been diagnosed with mild COVID-19 3 days earlier and presented to the emergency department with altered mental status. Brain magnetic resonance imaging (MRI) showed a high-intensity area confined to the splenium of the corpus callosum on diffusion-weighted imaging, which is consistent with MERS. MERS is characterized by a reversible change in the splenium of the corpus callosum. MERS secondary to COVID-19 has been reported recently. It is important to consider MERS in COVID-19 patients with impaired consciousness.

Predictive scoring system for distinguishing Stenotrophomonas maltophilia bacteremia from Pseudomonas aeruginosa bacteremia in patients with hematological malignancies

Difficulties in immediately distinguishing Stenotrophomonas maltophilia (SM) bacteremia from Pseudomonas aeruginosa (PA) bacteremia in the clinical setting can lead to treatment delay. We aimed to develop a scoring system to immediately distinguish SM bacteremia from PA bacteremia using clinical indicators. We enrolled cases of SM and PA bacteremia in adult patients with hematological malignancies between January 2011 and June 2018. The patients were randomized into derivation and validation cohorts (2:1), and a clinical prediction tool for SM bacteremia was developed and verified. In total, 88 SM and 85 PA bacteremia cases were identified. In the derivation cohort, the following independent predictors of SM bacteremia were identified: no evidence of PA colonization, antipseudomonal β-lactam breakthrough bacteremia, and central venous catheter insertion. We scored each of the three predictors according to their regression coefficient (2, 2, and 1, respectively). Receiver operating characteristic curve analysis confirmed the score's predictive performance, with an area under the curve of 0.805. The combined sensitivity and specificity (0.655 and 0.821) was highest with a cut-off value of 4 points. Positive and negative predictive values were 79.2% (19/24) and 69.7% (23/33), respectively. This novel predictive scoring system is potentially useful for distinguishing SM bacteremia from PA bacteremia, which would facilitate immediate administration of appropriate antimicrobial therapy.

Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia

OBJECTIVES

To evaluate the efficacy and safety of nafamostat combined with favipiravir for the treatment of COVID-19.

METHODS

We conducted a multicenter, randomized, single-blind, placebo-controlled, parallel assignment study in hospitalized patients with mild-to-moderate COVID-19 pneumonia. Patients were randomly assigned to receive favipiravir alone (n = 24) or nafamostat with favipiravir (n = 21). The outcomes included changes in the World Health Organization clinical progression scale score, time to improvement in body temperature, and improvement in oxygen saturation (SpO₂).

RESULTS

There was no significant difference in the changes in the clinical progression scale between nafamostat with favipiravir and favipiravir alone groups (median, -0.444 vs -0.150, respectively; least-squares mean difference, -0.294; P = 0.364). The time to improvement in body temperature was significantly shorter in the combination group (5.0 days; 95% confidence interval, 4.0-7.0) than in the favipiravir group (9.0 days; 95% confidence interval, 7.0-18.0; P =0.009). The changes in SpO₂ were greater in the combination group than in the favipiravir group (0.526% vs -1.304%, respectively; least-squares mean difference, 1.831; P = 0.022). No serious adverse events or deaths were reported, but phlebitis occurred in 57.1% of the patients in the combination group.

CONCLUSION

Although our study showed no differences in clinical progression, earlier defervescence, and recovery of SpO₂ were observed in the combination group.

Microbiome of infected cysts, feces and saliva in patients with autosomal dominant polycystic kidney disease

Cyst infection is a frequent and serious complication of autosomal dominant polycystic kidney disease (ADPKD). Hematogenous spread via bacterial translocation in the intestine is considered to be the main cause, so intestinal flora may be involved. However, the exact role of the intestinal flora in cyst infection in ADPKD is unknown. We report a 66-year-old woman and a 56-year-old man with ADPKD who had severe hepatic cyst infection. We analyzed the microbiome of infected cyst content, feces, and saliva in these two patients. The microbiome of patient 1 showed various bacteria in an infected cyst, whereas that of patient 2 showed only one bacterium. In both patients, the composition of the microbiome of the cyst content was quite different from those of feces and saliva, and the main bacteria in the infected cyst content represented a small proportion of those in feces and saliva. Lactobacilli were not almost detected in the infected cyst content though some lactobacilli are endemic in the gastrointestinal tract and the saliva. The association between bacteria in cysts and those in feces or saliva remains uncertain, and further research on this topic is needed.

Clinical and microbiological characteristics of bacterial meningitis in umbilical cord blood transplantation recipients

Bacterial meningitis is a rare but severe infectious complication after hematopoietic stem cell transplantation. However, its clinical features were previously not clear. We reviewed the cases of 7 patients diagnosed with bacterial meningitis with a positive cerebrospinal fluid culture among 1147 patients who underwent cord blood transplantation (CBT) at our institution between September 2007 and September 2020. The diagnosis was made on day + 5- + 45, and 5 patients developed bacterial meningitis before neutrophil engraftment. The causative organisms were all Gram-positive cocci: Enterococcus faecium and Enterococcus gallinarum (2 patients each), and Staphylococcus haemolyticus, Streptococcus mitis/oralis, and Rothia mucilaginosa (1 patient each). Six patients developed bacterial meningitis secondary to prior or concomitant bacteremia caused by the same bacterium. Five patients had received anti-MRSA agents at onset: vancomycin in 3, teicoplanin in 1, and daptomycin in 1. After diagnosis of bacterial meningitis, linezolid was eventually used for 6 patients. Two patients with E. gallinarum were alive at day + 1380 and + 157 after CBT, respectively, whereas 5 patients died 17-53 (median 43) days after the onset of bacterial meningitis. Breakthrough meningitis in CBT can occur even during the use of anti-MRSA drugs, and intensive antibiotic treatment is necessary.

Clinical characteristics and drug susceptibility patterns of Corynebacterium species in bacteremic patients with hematological disorders

The aim of this study was to clarify the clinical and microbiological characteristics of Corynebacterium bacteremia in hematological patients. We retrospectively reviewed the medical records of patients with Corynebacterium bacteremia from April 2013 to June 2018. The causative Corynebacterium species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Drug susceptibility tests were performed using the broth microdilution method recommended by the Clinical and Laboratory Standards Institute. In total, 147 cases of Corynebacterium bacteremia were identified during the study period. Corynebacterium striatum was the most frequent pathogen. Catheter-related bloodstream infection was diagnosed in 19.7% of all patients, and moderate/severe oral or severe gastrointestinal mucosal impairment was detected in 19.7%. Polymicrobial infection was found in about 20% of cases, with Enterococcus faecium being the most frequent isolate. The overall 30-day mortality was 34.7% (51/147). Multivariate analysis showed that E. faecium co-infection (odds ratio (OR) 9.3; 95% confidence interval (CI) 2.1-40), systemic corticosteroids (OR 3.6; 95% CI 1.4-8.9), other immunosuppressive drugs (OR 0.32; 95% CI 0.13-0.76), and a Pitt bacteremia score ≥4 (OR 12; 95% CI 3.9-40) were significant risk factors for overall 30-day mortality. The drug susceptibility rates for beta-lactam antimicrobial agents were quite low. All isolates were susceptible to glycopeptides and linezolid. However, some C. striatum isolates were resistant to daptomycin. Corynebacterium bacteremia can occur in the presence of several types of mucosal impairment. Our drug susceptibility data indicate that Corynebacterium bacteremia in hematological patients could be treated by glycopeptides or linezolid.

Reverse Transcription Loop-Mediated Isothermal Amplification Assay-Based Infection Control Strategies for COVID-19 in a Hospital Under the State of Emergency in Tokyo, Japan in Spring 2020

Studies describing reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay-based infection control strategies (LAMP-based ICSs) for coronavirus disease 2019 (COVID-19) are limited. We reviewed the medical records of cases in which RT-LAMP was performed. Standard ICSs and LAMP-based ICSs were implemented during the study period. The strategies were intended to impose longer periods of infection control precautions (ICPs) for specific patients, such as those with a history of exposure to COVID-19 patients and/or bilateral ground glass opacities (bGGO) on chest computed tomography (CT). Of 212 patients, which included 13 confirmed COVID-19 patients in the diagnostic cohort, exposure to COVID-19 patients (P <0.0001) and chest CT bGGO (P = 0.0022) were identified as significant predictors of COVID-19. In the 173 hospitalized patients in which the results of the first RT-LAMP were negative, the duration of ICPs was significantly longer in patients with exposure to COVID-19 and/or a high clinical index of suspicion and patients with bGGO than in the remaining patients (P = 0.00046 and P = 0.0067, respectively). Additionally, no confirmed COVID-19 cases indicating nosocomial spread occurred during the study period. Establishing a comprehensive system that combines rational LAMP-based ICSs with standard ICSs might be useful for preventing nosocomial spread.

Stenotrophomonas maltophilia bloodstream infections in adult recipients of umbilical cord blood transplantation

Limited data are available on Stenotrophomonas maltophilia bloodstream infections (SM-BSIs) and the therapeutic efficacy of trimethoprim-sulfamethoxazole (SXT) against SM-BSI in umbilical cord blood transplant (uCBT) recipients. Medical and microbiological records of adult patients who received uCBTs between December 2008 and December 2015 at Toranomon Hospital (Tokyo, Japan) were reviewed. The efficacy and safety of SXT were evaluated only for recipients who were treated with ≥7 days of intravenous SXT for SM-BSI (evaluation cohort). Of 561 uCBT recipients, 34 developed SM-BSI. Diabetes mellitus (P = .005) and age ≥ 60 years (P = .013) were significant independent risk factors for SM-BSI. Moreover, SM-BSI was identified as an independent risk factor for all-cause mortality up to 100 days following uCBT (P = .025). Of the 34 recipients with SM-BSI, 24 were treated with an intravenous SXT-containing regimen (iSXT-CR). Septic shock (P = .0021), pneumonia (P = .011), neutropenia (P = .0015), and systemic steroid administration (P = .018) were identified as significant independent risk factors for 7-day crude mortality. The evaluation cohort included nine recipients. Doses of SXT were 2.4 to 6.9 mg/kg/day of the trimethoprim component. Of the nine recipients, five developed SM-BSI during the pre-engraftment phase. The 30-day crude-mortality rate and clinical cure rate of the cohort were 22% and 67%, respectively. Only one of the nine recipients experienced significant neutrophil toxicity. In this study, the epidemiology of SM-BSI in uCBT recipients was determined and its negative impact on survival was demonstrated. A low- to moderate-dose iSXT-CR appeared to be a tolerable and important therapeutic option for SM-BSI in the uCBT setting, including during the pre-engraftment phase.

Characteristics of gram-negative bacteremia during febrile neutropenia among allogeneic hematopoietic stem cell transplant recipients on levofloxacin prophylaxis

The aim of this study is to clarify the characteristics of gram-negative bacteremia (GNB), including extended-spectrum β-lactamase (ESBL)-producing pathogens, among allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients on levofloxacin (LVFX) prophylaxis. A retrospective analysis on GNB at the first episode of febrile neutropenia (FN) was conducted among allo-HSCT recipients (age ≥ 20 years) on 500 mg/day of oral LVFX prophylaxis. Epidemiological and microbiological features of GNB were investigated and compared between the inappropriate and appropriate empiric therapy groups. In total, FN occurred in 414 allo-HSCT cases, and bacteremia at the first episode of FN occurred in 169 cases. Overall, 29 GNB cases were documented, and the causative organisms identified were Escherichia coli in 21 cases (including 10 ESBLs), Klebsiella pneumoniae in 2, Pseudomonas aeruginosa in 2, and other in 4. The crude 30-day mortality rate was not significantly different among cases of GNB (6.9%), gram-positive bacteremia (GPB) (7.1%), or non-bacteremia (5.4%; P = 0.78). Cefepime (CFPM) was administered in all cases in the inappropriate empiric therapy group, and all causative organisms were ESBL-producing E. coli (ESBL-EC). All patients in the inappropriate empiric therapy group had a low Pitt bacteremia score (≤ 2). Thirty-day mortality did not differ significantly between the inappropriate and appropriate empiric therapy groups (1/10 vs. 1/15, P = 0.61). In conclusion, GNB was not a significant cause of death. In LVFX breakthrough ESBL-EC bacteremia among allo-HSCT recipients, the administration of CFPM as empiric therapy did not lead to significantly poor prognosis. Empiric CFPM administration might be an acceptable strategy.

Safety of bronchoscopy in patients with malignant hematologic disorders

Background

Factors affecting the safety of bronchoscopy in patients with malignant hematologic disorders have not been well described. We evaluated the safety of bronchoscopy and describe factors affecting its complication rate in such patients.

Methods

Between January 2009 and December 2018, 316 bronchoscopies in 282 patients with malignant hematologic disorders and pulmonary infiltrates were performed at our institution. The bronchoscopic procedure used and its complications were evaluated.

Results

The most common underlying disease was acute myeloid leukemia (134/282 patients, 47.5%). Platelet transfusion was performed the day before or the day of bronchoscopy in 42.4%, supplemental oxygen was administered before the procedure in 23.1%, and midazolam was used in 74.4%. Thirty-five bronchoscopies (11.1%) were complicated by hemoptysis and 7 patients developed pneumothorax, 4 of whom required thoracic drainage. Two patients (0.6%) were intubated within 48 h of the procedure and prolonged oxygen desaturation (> 48 h) occurred in 3.8%. Multivariate analysis showed that only use of midazolam significantly reduced the risk of prolonged oxygen desaturation (hazard ratio 0.28, 95% confidence interval 0.09–0.85, p = 0.03). Transbronchial lung biopsy significantly increased the risk of hemoptysis (hazard ratio 10.40, 95% confidence interval 4.18–25.90, p = 0.00), while use of midazolam significantly reduced the risk (hazard ratio 0.31, 95% confidence interval 0.14–0.73, p = 0.01).

Conclusions

Bronchoscopy is relatively safe in patients with malignant hematologic disorders. Caution and judicious use of sedatives may improve the patient’s procedural tolerance and lower complications.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry can be used to identify Helicobacter cinaedi

We examined the applicability of Matrix-assisted laser desorption ionization-time of flight mass spectrometry using 54 Helicobacter cinaedi isolates from humans. In all 54 isolates, MALDI-TOF MS detected H. cinaedi as the best match organism. Our findings suggest that MALDI TOF-MS can be used effectively to identify H. cinaedi.

Risk Factors for Recurrent Helicobacter cinaedi Bacteremia and the Efficacy of Selective Digestive Decontamination With Kanamycin to Prevent Recurrence

Background

Previous studies suggest that Helicobacter cinaedi can cause recurrent bacteremia. In this study, we elucidated the risk factors for recurrent H. cinaedi bacteremia and explored the efficacy of selective digestive decontamination (SDD) as a preventive measure.

Methods

We retrospectively reviewed the medical records of patients with H. cinaedi bacteremia between March 2009 and December 2016 at 2 Japanese hospitals.

Results

We identified 168 patients with H. cinaedi bacteremia. Bacteremia recurred in 34 patients. The 100-day cumulative incidence rate of recurrent bacteremia was 18.7%. In univariate analysis of factors associated with recurrent bacteremia, anticancer chemotherapy (hazard ratio [HR], 3.75; 95% confidence interval [CI], 1.86-7.58; P < .001), systemic steroids (HR, 3.79; 95% CI, 1.70-8.45; P = .0011), and hematological malignancy (HR, 3.18; 95% CI, 1.64-6.19; P < .001) were detected. Multivariate analysis indicated that anticancer chemotherapy (HR, 2.47; 95% CI, 1.19-5.12; P = .015) and systemic steroids (HR, 2.40; 95% CI, 1.03-5.61; P = .044) were the independent risk factors. Of the 168 patients, 47 received SDD. According to Gray's test, SDD might have reduced the rate of recurrence but this was not statistically significant (HR, 0.46; 95% CI, 0.18-1.18; P = .11). However, in a proportional hazard modeling analysis, SDD reduced the rate of recurrence (HR, 0.36; 95% CI, 0.13-1.00; P = .050).

Conclusions

The 100-day cumulative incidence of recurrent H. cinaedi bacteremia was 18.7%. Anticancer chemotherapy and systemic steroids were independent risk factors for recurrent bacteremia. SDD is a potential strategy for reducing the recurrence.

[Cytomegalovirus meningoencephalitis in a diffuse large B-cell lymphoma patient undergoing salvage chemotherapy]

A 63-year-old woman was admitted to our hospital to receive a fourth course of modified rituximab-ESHAP chemotherapy for relapsed primary breast diffuse large B-cell lymphoma. She developed hemophagocytic lymphohistiocytosis (HLH) 20 days after admission. Polymerase chain reaction (PCR) detected cytomegalovirus (CMV) DNA in her peripheral blood; therefore, she was diagnosed with CMV-associated HLH and consequently treated with foscarnet (FCN). Her general condition and pancytopenia soon improved, and the antiviral drug was stopped for 1 week. However, she suddenly became disoriented 10 days later, and this condition rapidly worsened. Cerebrospinal fluid (CSF) examination revealed an elevated white blood cell count with lymphocytic predominance and a high CMV DNA load, prompting a final diagnosis of CMV meningoencephalitis. We began intravenous combination therapy with FCN and ganciclovir (GCV), and her conscious state gradually improved. CMV DNA sequencing did not reveal drug resistance associated with mutations, and intravenous GCV was stopped for 1 week. FCN treatment was then continued until CMV DNA was no longer detected in her CSF samples via PCR. CMV meningoencephalitis is a rare neurological infection complicated with hematological malignancy in non-transplant patients and can be serious and life-threatening with a high mortality rate. This infection requires a differential diagnosis of consciousness impairment that develops in a patient with lymphoid malignancy during chemotherapy.

Differences in Ocular Complications Between Candida albicans and Non-albicans Candida Infection Analyzed by Epidemiology and a Mouse Ocular Candidiasis Model

Objectives:Candida species are a major cause of hospital infections, including ocular candidiasis, but few studies have examined the propensities of specific species to invade the eye or the unique immunological responses induced. This study examined the frequency and characteristics of species-specific Candida eye infections by epidemiology and experiments using a mouse ocular candidiasis model.

Methods: We reviewed medical records of candidemia patients from January 2012 to March 2017. We also evaluated ocular fungal burden, inflammatory cytokine and chemokine profiles, and inflammatory cell profiles in mice infected with Candida albicans, Candida glabrata, or Candida parapsilosis.

Results: During the study period, 20 ocular candidiasis cases were diagnosed among 99 candidemia patients examined by ophthalmologists. Although C. parapsilosis was the most frequent candidemia pathogen, only C. albicans infection was significantly associated with ocular candidiasis by multivariate analysis. In mice, ocular fungal burden and inflammatory mediators were significantly higher during C. albicans infection, and histopathological analysis revealed invading C. albicans surrounded by inflammatory cells. Ocular neutrophil and inflammatory monocyte numbers were significantly greater during C. albicans infection.

Conclusion:Candida albicans is strongly associated with ocular candidiasis due to greater capacity for invasion, induction of inflammatory mediators, and recruitment of neutrophils and inflammatory monocytes.

Cryptococcal meningitis following umbilical cord blood transplantation, association between the occurrence of cryptococcal infection and tacrolimus discontinuation among allogeneic hematopoietic stem cell recipients

Few cases of cryptococcal infection following umbilical cord blood transplantation (UCBT) have been reported. We report a case, where cryptococcal infection occurred soon after rapidly reducing the dose of tacrolimus in a UCBT recipient who received micafungin prophylaxis during the early phase of transplantation. The etiology of cryptococcal infection following allogeneic hematopoietic stem cell transplantation (allo-HSCT), including UCBT, might be associated with rapid dose-reduction of calcineurin inhibitors, such as tacrolimus during early phase of allo-HSCT. To our knowledge, this is the first English-language report to describe in detail a case of cryptococcal meningitis with fungemia during early phase of UCBT.

First case of sexually transmitted asymptomatic female genital tuberculosis from spousal epididymal tuberculosis diagnosed by active screening

Tuberculosis screening was performed for a healthy asymptomatic woman to determine whether she had been infected with active genital tuberculosis via sexual intercourse with her husband who had epididymal tuberculosis. Vaginal swab culture yielded Mycobacterium tuberculosis. Furthermore, whole genome sequencing revealed that the two causative isolates were genetically identical. This appears to be the first report on the sexual transmission of genital tuberculosis from a man to an asymptomatic woman, detected by active screening for genital tuberculosis and molecular analysis, including whole genome sequencing. Active screening for genital tuberculosis in the female partner should be considered soon after diagnosis of male genital tuberculosis, even when the female partner is asymptomatic.

The Diagnosis of Legionella pneumophila Serogroup 5 Bacteremic Pneumonia during Severe Neutropenia Using Loop-mediated Isothermal Amplification

A 60-year-old man developed pneumonia after undergoing autologous peripheral blood stem cell transplantation for diffuse large-B cell lymphoma. A urinary antigen test and sputum culture were both negative for Legionella pneumophila; however, a sputum sample that was examined by loop-mediated isothermal amplification (LAMP) was positive for Legionella spp. On admission, the results of blood culturing using a BACTEC system were negative for 7 days. However, L. pneumophila serogroup 5 was detected in a blood subculture using WYOα medium. The patient was successfully treated with a fluoroquinolone-based regimen. LAMP is useful for the diagnosis of Legionella spp.

First evidence of bacterial translocation from the intestinal tract as a route of Helicobacter cinaedi bacteremia

BACKGROUND

The route of Helicobacter cinaedi bacteremia has not yet been clarified. Although bacterial translocation from the intestinal tract into the circulation has been suggested, it has not been demonstrated thus far. The objective of this study was to investigate the port of entry of this bacterium.

MATERIAL AND METHODS

We conducted a retrospective study on patients with H. cinaedi bacteremia between March 2009 and May 2013. Records of patients in whom H. cinaedi was detected in both blood and stool cultures were extracted. H. cinaedi was identified using gyrB-targeted PCR. Pulse-field gel electrophoresis was used to investigate the consistency of the genotypes.

RESULTS

Seventy-one patients were diagnosed with H. cinaedi bacteremia during the study period. H. cinaedi was detected in both blood and stool samples of 21 patients. Pulse-field gel electrophoresis was used to investigate the consistency of the genotypes in 18 evaluable strains (from 9 patients). The pulse-field gel electrophoresis patterns of the stool- and blood-derived strains of H. cinaedi were consistent among all 9 patients. Most of the 9 patients analyzed were immunocompromised and being treated with anticancer drugs or steroids, which suggests reduced intestinal immunity.

CONCLUSIONS

This is the first study to demonstrate that bacterial translocation from the intestinal tract could represent one route of H. cinaedi bacteremia.

Successful Treatment of Pulmonary Mucormycosis Caused by Cunninghamella bertholletiae with High-Dose Liposomal Amphotericin B (10 mg/kg/day) Followed by a Lobectomy in Cord Blood Transplant Recipients

Infection caused by Cunninghamella bertholletiae carries one of the highest mortality rates among mucormycosis, and there are no reported cases that survived from the infection in allogeneic hematopoietic stem cell transplantation recipients occurring before neutrophil engraftment. Here, we present two cases of pulmonary mucormycosis caused by C. bertholletiae occurring before neutrophil engraftment after cord blood transplantation. Both were successfully treated with high-dose liposomal amphotericin B (10 mg/kg/day) combined with micafungin, which was then followed by neutrophil recovery, reduction in immunosuppressive agents, and a subsequent lobectomy. The intensive antifungal therapy immediately administered upon suspicion of mucormycosis greatly suppressed the infection in its early stage and was well tolerated despite its prolonged administration and simultaneous use of nephrotoxic agents after transplantation. Although the synergic effect of micafungin remains unclear, these cases highlight the importance of prompt administration of high-dose lipid polyene when suspecting mucormycosis in highly immunocompromised patients, which enables subsequent diagnostic and therapeutic interventions, resulting in a favorable outcome.

Evaluation of trimethoprim-sulfamethoxazole based combination therapy against Stenotrophomonas maltophilia: in vitro effects and clinical efficacy in cancer patients

OBJECTIVES

The aim of this study was to evaluate the in vitro effects and clinical efficacies of trimethoprim-sulfamethoxazole (SXT) combined with other antimicrobial agents against Stenotrophomonas maltophilia.

METHODS

In vitro analysis was conducted on 89 S. maltophilia strains isolated from blood and the respiratory tract between June 2012 and October 2014. Levofloxacin (LVX), ticarcillin-clavulanic acid (TIM), and minocycline (MIN) were selected for an examination of their effects when individually combined with SXT by the checkerboard method. In addition, 29 S. maltophilia bacteremia cases were reviewed and the clinical efficacies of SXT-based combination therapies were analyzed.

RESULTS

SXT+LVX showed synergy in 21, no interactions in 61, and antagonism in 7. SXT+TIM showed synergy in 71, and no interactions in 18. SXT+MIN showed synergy in 10, and no interactions in 79. The review of clinical data indicated that a combination of SXT+fluoroquinolone was not associated with improved prognosis compared with monotherapy.

CONCLUSIONS

The in vitro data indicated that SXT+TIM had beneficial microbiological effects and was not antagonistic. Our in vitro and clinical data analyses do not support the routine use of SXT+fluoroquinolone combination therapy for S. maltophilia infection.

Unique characteristics of community-onset healthcare- associated bloodstream infections: a multi-centre prospective surveillance study of bloodstream infections in Japan

BACKGROUND

Analysis of bloodstream infections (BSIs) is valuable for their diagnosis, treatment and prevention. However, limited data are available in Japan.

AIM

To investigate the characteristics of patients with bacteraemia in Japan.

METHODS

This study was conducted in five hospitals from October 2012 to September 2013. Clinical, demographic, microbiological and outcome data for all blood-culture-positive cases were analysed.

FINDINGS

In total, 3206 cases of BSI were analysed: 551 community-onset healthcare-associated (CHA)-BSIs, 1891 hospital-acquired (HA)-BSIs and 764 community-acquired (CA)-BSIs. The seven- and 30-day mortality rates were higher in patients with CHA- and HA-BSIs than in patients with CA-BSIs. The odds ratios (ORs) for seven-day mortality were 2.56 [95% confidence interval (CI) 1.48-4.41] and 2.63 (95% CI 1.64-4.19) for CHA- and HA-BSIs, respectively. The ORs for 30-day mortality were 2.41 (95% CI 1.63-3.57) and 3.31 (95% CI 2.39-4.59) for CHA- and HA-BSIs, respectively. There were 499 cases (15.2%) of central-line-associated BSI and 163 cases (5.0%) of peripheral-line-associated BSI. Major pathogens included coagulase-negative staphylococci (N = 736, 23.0%), Escherichia coli (N = 581, 18.1%), Staphylococcus aureus (N = 294, 9.2%) and Klebsiella pneumoniae (N = 263, 8.2%). E. coli exhibited a higher 30-day mortality rate among patients with HA-BSIs (22.3%) compared with patients with CHA-BSIs (12.3%) and CA-BSIs (3.4%). K. pneumoniae exhibited higher 30-day mortality rates in patients with HA-BSIs (22.0%) and CHA-BSIs (22.7%) compared with patients with CA-BSIs (7.8%).

CONCLUSION

CHA- and HA-BSIs had higher mortality rates than CA-BSIs. The prognoses of E. coli- and K. pneumonia-related BSIs differed according to the category of bacteraemia.

Multicenter Study of the Clinical Presentation of Staphylococcus lugdunensis Bacteremia in Japan

Staphylococcus lugdunensis (SL) is a bacterium with a highly pathogenicity than most other coagulase-negative Staphylococcus spp. (CoNS). In Japan, data on this pathogen are sparse, and the current prevalence of SL bacteremia is unknown. Therefore, we investigated the prevalence of SL in blood culture specimens in a prospective multicenter study across 5 facilities. A total of 3,284 patients had positive blood cultures, and 2,478 patients had bacteremia. Among the patients with bacteremia, 7 patients (0.28%) had SL bacteremia. A total of 281 patients had CoNS bacteremia, with SL accounting for 2.49% of these cases. Of the 7 patients with SL bacteremia, 1 patient (14.3%) had infective endocarditis, and 1 patient (14.3%) died within 30 days. In this study, SL resulted in the development of bacteremia in select patients. Clinicians in Japan should be aware of the prevalence of SL and the complications of SL bacteremia.

Breakthrough viridans streptococcal bacteremia in allogeneic hematopoietic stem cell transplant recipients receiving levofloxacin prophylaxis in a Japanese hospital

Background

Breakthrough viridans streptococcal bacteremia (VSB) in patients with hematological malignancy receiving levofloxacin prophylaxis is a major blood stream infection (BSI) occurring during febrile neutropenia. However, clinical data focused on VSB in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are lacking.

Methods

The medical records of allo-HSCT recipients who received oral levofloxacin prophylaxis between January 2011 and August 2013 at Toranomon Hospital were reviewed to evaluate breakthrough VSB. Stored viridans streptococcal (VGS) species were identified by using sodA gene sequencing, and were assessed for drug susceptibility.

Results

Among the 184 allo-HSCT recipients on levofloxacin prophylaxis, 28 (15.2 %) experienced breakthrough VSB. All of the 28 recipients with VSB were treated with a cefepime-based or piperacillin/tazobactam-based regimen. The susceptibility rates of the VGS strains for levofloxacin, cefepime, piperacillin/tazobactam, meropenem, and vancomycin were 0 %, 95 %, 100 %, 100 %, and 100 %, respectively. Both the MIC₅₀ (minimum inhibitory concentration) and the MIC₉₀ of ceftazidim (0.5 μg/mL and 2 μg/mL, respectively) were higher than the MIC₉₀ of all the other anti-pseudomonal beta-lactams (APBLs). Only 1 VGS strain had a penicillin MIC ≥ 2 μg/mL by the Etest (3.6 %). There were no cases with acute respiratory distress syndrome (ARDS) that was associated with VSB, although the rate of viridans group streptococcal shock syndrome was high (26 %). The crude 30-day mortality rate in the VSB group (10.7 %) did not differ significantly from that in the BSI without VSB group (9.3 %) or non-BSI group (7.0 %) (P = 0.77). Also, VSB was not a risk factor for all-cause mortality up to 60 days following allo-HSCT (P = 0.43).

Conclusions

APBL with increased anti-VGS activity (APBL-VA) monotherapy would typically be optimal for treating the VGS strains in this setting. Indication of adding an empiric anti-gram-positive agent to APBL-VA for treating VSB should depend on local factors, such as the susceptibility results. In addition, breakthrough VSB is probably not a major cause of death in allo-HSCT settings, where beta-lactam non-susceptible VGS and the ARDS are rare.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1692-y) contains supplementary material, which is available to authorized users.

[Anticancer Drug Treatment Strategy for Cancer Patients with Chronic Infections]

It is difficult to determine whether anticancer treatment should be started for cancer patients with chronic infections. If an anticancer drug is administered to cancer patients with chronic infections, it is difficult to determine when anticancer therapy should be started. It is important to evaluate the current status of each patient's cancer and infections for decision-making. There is limited evidence in this area; therefore, we have to individualize our approach for each patient. Oncologists are expected to treat cancer patients in collaboration with infectious disease doctors.

Helicobacter cinaedi bacteremia in four renal transplant patients: clinical features and an important suggestion regarding the route of infection

Helicobacter cinaedi can cause bacteremia mainly in immunocompromised patients. We present the clinical characteristics of H. cinaedi bacteremia in 4 renal transplant patients. Interestingly, all cases showed triggers of bacterial translocation: 2 cases developed after colonic perforation caused by diverticulitis, 1 case developed post cholecystectomy, and the remaining patient had chronic diarrhea. Accordingly, bacterial translocation caused by severe gastrointestinal complication could be a cause of H. cinaedi bacteremia.

Serum (1,3)-beta-D-glucan is an inefficient marker of breakthrough candidemia

The aim of this study was to evaluate the usefulness of serum (1,3)-beta-D-glucan (BDG) for earlier detection of breakthrough candidemia. We reviewed the medical records of patients with candidemia from January 2008 to March 2013. Serum BDG was measured by Wako turbidimetric assay. During the study period, a total of 147 cases of candidemia were identified, and 31 patients met the criteria for breakthrough candidemia. Serum BDG levels were measured in 25 patients with breakthrough candidemia and 67 patients with nonbreakthrough candidemia. Almost all of the patients with breakthrough candidemia had hematological malignancies. More candidemia were caused by non-C. albicans Candida in the breakthrough group than in the nonbreakthrough group (92.0% vs. 61.8%, p = .005). The median BDG value was significantly lower in breakthrough episodes than in non-breakthrough episodes (18.5 pg/ml vs. 90.4 pg/ml, p = .01). Moreover, BDG values under the cutoff was significantly higher in patients with breakthrough candidemia than in those with nonbreakthrough candidemia (44% vs. 19%, p = .03). In summary, BDG alone was insufficient to detect breakthrough candidemia, and candidemia could occur in patients being treated with antifungal agents, even when the BDG value was under the cutoff value.

Varicella Zoster Virus Meningoencephalitis Presenting with Elsberg Syndrome without a Rash in an Immunocompetent Patient

Varicella zoster virus (VZV) infection usually manifests with a skin rash. To the best of our knowledge, this is the first report of a case of VZV meningoencephalitis presenting with Elsberg syndrome without a rash in an immunocompetent patient. Clinicians should consider the potential for VZV infection as well as herpes simplex virus infection in cases of aseptic meningitis accompanied by bladder and rectal disturbances, even in patients without any rash symptoms.

Relative incidences and outcomes of Clostridium difficile infection following transplantation of unrelated cord blood, unrelated bone marrow, and related peripheral blood in adult patients: a single institute study

BACKGROUND

Clostridium difficile is a major cause of nosocomial diarrhea. The incidence and prognosis of C. difficile-associated diarrhea (CDAD) has not yet been assessed in adult patients after unrelated cord blood transplantation (uCBT).

METHODS

The medical records of 135 adult unrelated cord blood transplant recipients were reviewed retrospectively to investigate the clinical features of CDAD after uCBT. These data were compared to medical records of 39 unrelated bone marrow transplant recipients and 27 related peripheral blood stem cell transplant recipients as controls.

RESULTS

A total of 17 recipients developed CDAD, with onset occurring at a median of 22 days (range, 0-56 days) after transplantation. Among the unrelated cord blood transplant recipients, 11 (9%) developed CDAD. These results were comparable with those of CDAD after unrelated bone marrow transplantation (uBMT) (2/39, 6%) and related peripheral blood stem cell transplantation (rPBSCT) (4/27, 16%) (P=0.37). Fifteen of the infected recipients were successfully treated with oral metronidazole, vancomycin, or cessation of antibiotics. The remaining 2 recipients who developed CDAD after uCBT died of other causes. The development of CDAD did not negatively affect overall survival after uCBT.

CONCLUSIONS

These data indicate that the incidence and prognosis of CDAD after uCBT are comparable with those after uBMT and rPBSCT.

Analysis of the influence of drug resistance factors on the efficacy of combinations of antibiotics for multidrug-resistant Pseudomonas aeruginosa isolated from hospitals located in the suburbs of Kanto area, Japan

Infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa are very difficult to treat. The aim of this study was to develop more effective treatments by investigating in vitro the effects of combinations of antibiotics against 47 MDR P. aeruginosa isolates harbouring various resistance factors. The isolates included 41 (87%) metallo-β-lactamase (MBL)-positive strains, 37 (79%) strains with mutations in OprD and 46 (98%) strains carrying the genes encoding aminoglycoside-modifying enzymes (AMEs). The quinolone resistance-determining region was mutated in all of the strains. These strains were classified into 16 groups according to amplified fragment length polymorphism and resistance factors. The effects of combinations of antibiotics on 16 representative strains were determined using a 'Break-point Checkerboard Plate' assay. Combinations of amikacin+aztreonam (coverage rate, 81.3%) and arbekacin+aztreonam (93.8%) inhibited growth. In contrast, combinations of ciprofloxacin+meropenem (6.3%) and ciprofloxacin+ceftazidime (12.5%) were much less effective. Aztreonam and arbekacin (or amikacin) are not substrates for MBLs and AMEs, respectively. We conclude that the combined effects of these drugs were possibly because of resistance factors.

A surveillance of high-level gentamicin-resistant enterococcal bacteremia

Enterococci have recently been recognized as a causative organism of intractable infections, including severe sepsis and infective endocarditis, in immunocompromised patients. This study investigated the epidemiological, microbiological, and prognostic characteristics of high-level gentamicin-resistant (HLGR) enterococcal bacteremia, including severe cases of infective endocarditis, in Japan. A total of 155 enterococcal bacteremia episodes were identified between July 2007 and December 2009. HLGR strains accounted for 28% of all enterococcal strains: HLGR Enterococcus faecalis/Enterococcus faecium strains accounted for 32%/24%. The 30-day mortality rate was 31%. There was no significant difference in the 30-day mortality rates between HLGR and non-HLGR enterococcal bacteremia. There were two cases of HLGR enterococcal endocarditis, which were successfully treated with ampicillin plus ceftriaxone. We consider it important to examine the presence or absence of HLGR strains in all cases of intractable enterococcal infection, especially infective endocarditis.

[Combination therapy against multidrug-resistant bacteria]

The purpose of antibiotic combination therapy includes two points, as follows; 1) expectation of synergistic effects, 2) preventing the emergence of drug-resistant bacteria following exposure to antibiotics. Synergism has been shown in vitro for many antibiotic combinations and bacterial species, but it is uncertain whether synergistic effects in vitro are applicable to the clinical setting and lead to a better prognosis. beta-lactam and aminoglycoside combinations have synergistic effects against Gram-negative bacteria, including Pseudomonas aeruginosa, Klebsiella, Escherichia coli, and other Enterobacteriaceae in vitro; however, combination therapy is not considered for these pathogens routinely in vivo. Multidrug-resistant (MDR) pathogens have emerged as increasingly problematic causes of hospital-acquired infection. When MDR Gram-negative bacillary infection occurs in immunocompromised patients, combination therapy is considered. In Japan, MDR P. aeruginosa is becoming a serious problem in the clinical setting. Here, we present an antibiotic combination therapeutic strategy against MDR P. aeruginosa infection.

Rapidly progressive fatal hemorrhagic pneumonia caused by Stenotrophomonas maltophilia in hematologic malignancy

BACKGROUND

Pneumonia caused by Stenotrophomonas maltophilia is rare, but can be lethal in severely immunocompromised patients. However, its clinical course remains unclear.

PATIENTS AND METHODS

Patients with pneumonia caused by S. maltophilia in Toranomon Hospital (890 beds, Tokyo, Japan) were reviewed retrospectively between April 2006 and March 2010.

RESULTS

During the study period, 10 cases of S. maltophilia pneumonia were identified. Seven patients had acute myeloid leukemia, 2 had myelodysplastic syndrome, and 1 had malignant lymphoma. All patients developed symptoms after allogeneic hematopoietic stem cell transplantation (HSCT). Five patients received first cord blood transplantation (CBT), 4 patients received second CBT, and 1 patient received first peripheral blood stem cell transplantation (PBSCT). The overall incidence of S. maltophilia pneumonia among 508 patients who received HSCT during the period was 2.0%. The incidence was 0% (0/95) in patients after bone marrow transplantation, 0.8% (1/133) after PBSCT, and 3.2% (9/279) after CBT. Pneumonia developed a median of 13.5 days (range, 6-40) after transplantation. At onset, the median white blood cell count was 10/μL (range, 10-1900), and the median neutrophil count was 0/μL (range, 0-1720). In all patients, S. maltophilia bacteremia developed with bloody sputum or hemoptysis. The 28-day mortality rate was 100%; the median survival after onset of pneumonia was 2 days (range, 1-10).

CONCLUSIONS

Hemorrhagic S. maltophilia pneumonia rapidly progresses and is fatal in patients with hematologic malignancy. Attention should be particularly paid to the neutropenic phase early after HSCT or prolonged neutropenia due to engraftment failure. A prompt trimethoprim-sulfamethoxazole-based multidrug combination regimen should be considered to rescue suspected cases of S. maltophilia pneumonia in these severely immunosuppressed patients.

In vitro combination effects of aztreonam and aminoglycoside against multidrug-resistant Pseudomonas aeruginosa in Japan

The aim of this study was to evaluate the in vitro combination effects of aztreonam (AZT) and aminoglycosides against multidrug-resistant (MDR) Pseudomonas aeruginosa strains in Japan. We investigated 47 MDR P. aeruginosa strains collected from 8 facilities. We selected the aminoglycosides amikacin (AMK), gentamicin (GM), and arbekacin (ABK) to examine their effects when combined with AZT using the checkerboard method. Of the 47 MDR P. aeruginosa strains, 41 tested positive for metallo-β-lactamase (MBL). In all combinations, aminoglycosides decreased the minimum inhibitory concentrations of AZT in a dose-dependent manner, and there was no apparent antagonism. The combination effects were scored on a scale of 0 to 4, and statistical analysis was performed using the Wilcoxon signed-rank test. In all 47 strains, AZT + ABK (mean score, 2.02) had the highest score, followed by AZT + AMK (1.68) and AZT + GM (1.38) (ABK versus GM, P < 0.0001). In 41 MBL-positive strains, AZT + ABK (mean score, 2.05) had the highest score, followed by AZT + AMK (1.56) and AZT + GM (1.37) (ABK versus AMK, P = 0.02, and ABK versus GM, P < 0.0001). AZT + ABK was the most promising combination regimen against MDR P. aeruginosa strains; the other promising combinations were AZT + AMK and AZT + GM.

Cunninghamella bertholletiae pneumonia showing a reversed halo sign on chest computed tomography scan following cord blood transplantation

This is the first reported case of a patient who developed fungal pneumonia caused by Cunninghamella bertholletiae (= C. elegans) following cord blood transplantation and who showed a reversed halo sign on a chest computed tomography scan (CT). In addition, the pathological findings related to the reversed halo sign are described in detail for the first time. The patient died due to respiratory failure and at autopsy, a consolidation corresponding to the reversed halo sign noted on CT was found histologically to be composed of a central infarct with some retained air spaces surrounded by a peripheral ring-like hemorrhagic band. Pulmonary vasculatures were occluded by thrombi containing numerous Zygomycetes hyphae within the central infarct and less frequently along the surrounding hemorrhagic band. A reversed halo sign may be an early marker to initiate preemptive therapy against Zygomycetes including C. bertholletiae.