Clinical characteristics and antimicrobial susceptibility of Fusobacterium species isolated over 10 years at a Japanese university hospital.

PURPOSE: Anaerobic bacteria, existing on human skin and mucous membranes, can cause severe infections with complications or mortality. We examined the clinical characteristics of patients infected with Fusobacterium spp. and assessed their antibiotic susceptibility. METHODS: Clinical data were collated from patients diagnosed with Fusobacterium infections in a Japanese university hospital between 2014 and 2023. Antibiotic susceptibility tests were conducted following the Clinical and Laboratory Standards Institute guidelines. RESULTS: We identified 299 Fusobacterium isolates. The median age was 61 years (range, 14-95 years), with females constituting 43.1% of the patients. Most infections were community-acquired (84.6%, 253/299). Multiple bacterial strains were isolated simultaneously in 74.6% of cases. One-fourth of the patients had solid organ malignancies (25.4%, 76/299), and 14.5% (11/76) of those had colorectal cancer. The 30-day mortality rate was 1.3%. Fusobacterium species were isolated from blood cultures in 6% (18/299) of the patients. Patients, aged 75 years or older, with cerebrovascular disease or hematologic malignancy exhibited significantly higher prevalence of blood culture isolates in univariate analysis. Each Fusobacterium species had its characteristic infection site. Approximately 5% F. nucleatum and F. necrophorum isolates showed penicillin G resistance. Moxifloxacin resistance was observed in varying degrees across strains, ranging from 4.6 to 100% of isolates. All isolates were sensitive to ß-lactam/ß-lactamase inhibitors, carbapenems, and metronidazole. CONCLUSION: We show a link between Fusobacterium species and solid organ malignancies. We observed resistance to penicillin, cefmetazole, clindamycin, and moxifloxacin, warranting caution in their clinical use. This study offers valuable insights for managing Fusobacterium infections and guiding empirical treatments.

Intra-Abdominal Abscess and Bacteremia Due to Stenotrophomonas maltophilia After Total Gastrectomy: A Case Report and Literature Review.

Stenotrophomonas maltophilia (S. maltophilia) is increasingly recognized as a pathogen responsible for nosocomial infections, particularly in immunocompromised patients. The most common types of S. maltophilia infections are pneumonia and catheter-related bloodstream infection, and clinical cases of intra-abdominal abscesses due to S. maltophilia are rare. We present a rare case of intra-abdominal abscess and bacteremia as a surgical site infection (SSI) caused by S. maltophilia in a patient following total gastrectomy. We also reviewed previous literature to elucidate the clinical characteristics of intra-abdominal abscess due to S. maltophilia. The patient, a 75-year-old man with diabetes and polymyositis (treated with prednisolone), developed a fever 17 days after undergoing a total gastrectomy for gastric cancer. Abdominal computed tomography revealed a hypodense solid mass at the esophagojejunostomy site, which appeared to be an intra-abdominal abscess. The culture of both blood and drained abscess pus confirmed only S. maltophilia. Treatment with intravenous trimethoprim-sulfamethoxazole and abscess drainage led to complete resolution. The patient recovered and was discharged and did not experience a recurrence. We reviewed the English literature and found only two additional case reports of intra-abdominal abscesses caused by S. maltophilia. As in our case, the intra-abdominal abscess occurred after abdominal surgery and the source was suspected to be deep SSI. This case highlights the importance of considering S. maltophilia as a potential pathogen in patients with atypical post-surgical abdominal infections. Physicians should be aware that S. maltophilia has the potential to cause intra-abdominal abscesses secondary to SSI, in addition to Enterobacteriaceae, a major causative pathogen of SSI. Further studies are required to elucidate the etiology, epidemiology, and risk factors for SSI caused by S. maltophilia.

Real-World Experience of the Comparative Effectiveness and Safety of Combination Therapy with Remdesivir and Monoclonal Antibodies versus Remdesivir Alone for Patients with Mild-to-Moderate COVID-19 and Immunosuppression: A Retrospective Single-Center Study in Aichi, Japan.

The coronavirus disease (COVID-19) pandemic continues to threaten global public health. Remdesivir and monoclonal antibodies have shown promise for COVID-19 treatment of patients who are immunocompromised, including those with cancer, transplant recipients, and those with autoimmune disorder. However, the effectiveness and safety of this combination therapy for patients who are immunosuppressed remain unclear. We compared the efficacy and safety of combination therapy and remdesivir monotherapy for patients with mild-to-moderate COVID-19 who were immunosuppressed. Eighty-six patients treated in July 2021-March 2023 were analyzed. The combination therapy group (CTG) showed a statistically significant reduction in viral load compared with the monotherapy group (MTG) (p < 0.01). Patients in the CTG also experienced earlier resolution of fever than those in the MTG (p = 0.02), although this difference was not significant in the multivariate analysis (p = 0.21). Additionally, the CTG had significantly higher discharge rates on days 7, 14, and 28 than the MTG (p < 0.01, p < 0.01, and p = 0.04, respectively). No serious adverse events were observed with combination therapy. These findings suggest that combination therapy may improve the clinical outcomes of immunosuppressed COVID-19 patients by reducing the viral load and hastening recovery. Further studies are required to fully understand the benefits of this combination therapy for immunocompromised COVID-19 patients.

Complicated pyelonephritis caused by Proteus alimentorum in a woman with peritoneal cancer: a case report.

BACKGROUND: Proteus spp. are widespread in the environment and comprise a part of the normal flora of the human gastrointestinal tract. Only six species in this genus, including Proteus mirabilis, Proteus vulgaris, Proteus terrae, Proteus penneri, Proteus hauseri, and Proteus faecis, have been isolated from human clinical specimens. However, there are no reports of Proteus alimentorum isolated from humans, and the clinical characteristics of P. alimentorum infection are unknown. CASE PRESENTATION: An 85-year-old female patient with peritoneal cancer was hospitalized for complicated pyelonephritis and bacteremia caused by P. alimentorum. The patient received antimicrobial therapy and was discharged on day 7 of hospitalization. No recurrence was observed 14 days after the treatment. Various methods were used to identify the Proteus sp. Furthermore, the VITEK-2 GN ID card resulted in low discrimination between P. hauseri and P. penneri. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry showed P. hauseri with a spectral score of 2.22 as the best match. Nevertheless, the pathogen was identified as P. alimentorum based on genetic investigation using 16 S rRNA gene sequencing and biochemical tests. CONCLUSION: Proteus alimentorum is a human pathogen, and its infection has an excellent therapeutic response to antimicrobials based on antimicrobial susceptibility. Genomic methods may be helpful for the precise identification of P. alimentorum.

Three Successfully Treated Cases of Lodderomyces elongisporus Fungemia: Case Reports and a Review of the Literature.

Fungemia is a fatal systemic infection that can occur in immunocompromised patients. Despite that, antifungal stewardship is spreading widely, but the mortality rate is extremely high, showing 40-60%. Loderomyces elongiporus is a newly morphologically detected pathogen, first described in 1994, followed by isolation in humans in 2008. It has been misrecognized as Candida parapsilosis. Recently, fever attributable to L. elongisporus fungemia cases has been reported, and the etiology and clinical features are still unknown. Here, we present three successfully treated L. elongisporus fungemia cases by echinocandin. In total, 11 cases were reviewed, including ours. Six of the eleven cases (55%) had external devices. All cases had some immunocompromised conditions or underlying diseases, such as diabetes mellitus, lung cancer, etc. Six patients survived, and the remaining five died. Seven patients who had received echinocandin initially survived. Risk factors for L. elongiporus fungemia overlap with those of candidemia. Even though there is no breakpoint for L. elongiporus, echinocandin can be a helpful treatment regimen for L. elongiporus fungemia.

Empyema and bacteremia caused by Aeromonas hydrophila: Case report and review of the literature.

INTRODUCTION: Despite the advance in antibiotics and widespread chest tube drainage, acute empyema still shows a high mortality rate, accounting for 10-25%. We experienced a case of acute empyema caused by A. hydrophila, which is extremely uncommon, and reviewed all previously published articles. CASE PRESENTATION: A 76-year older man with a medical history of liver cirrhosis (LC) due to chronic hepatitis C and hepatic cell carcinoma was admitted to our institute. Elevated inflammatory reaction and effusions on chest CT were seen, and he was suspected of having acute empyema. Although an empiric antibiotic therapy of meropenem with chest tube drainage was performed as an initial treatment, he died within 8 hours of admission. Postmortem, both blood and left pleural fluid cultures yielded Aeromonas hydrophila. The final diagnosis was acute empyema caused by A. hydrophila. We reviewed previously reported empyema caused by Aeromonas species cases (4 A. hydrophila, and 1 A. veronii) in 4 previous reports written in English, including ours. Of 5, all were male, and the mean age was 52 years (range 27-76 years). All patients had LC due to alcohol or viral infections. As for antibiotics initially prescribed, third-generation cephalosporins were most frequently used in 3/5 (60%). Thoracentesis was performed in all patients (100%). As for prognosis, 2 (40%) survived, and 3 (60%) died. CONCLUSION: Physicians should be aware of the possibility of acute empyema caused by A. hydrophila among patients with chronic hepatic disease.

To what degree could clinical trials in evidence based medicine reflect reality in the treatment of candidemia?

INTRODUCTION: Evidenced based medicine (EBM) is necessary to standardize or treatment for infection since EBM is established based on the results of clinical trials. Entry criteria for clinical trials are very strict, and many patients have difficulties in being enrolled in any clinical trials regarding candidemia. It is questionable if the results of clinical trials reflect the real world of general medicine in this case. PATIENTS AND METHODS: For the purpose of examining how many patients could join any randomized clinical trials for the treatment of candidemia, we reviewed all the candidemia patients in our institute during 2014-2018. The patients were divided into two groups: patients who were eligible for clinical trials (participation possible group), and those who were not (participation impossible group). Exclusion criteria for clinical trials were set based on previous clinical trials. RESULTS: A total of 70 patients was enrolled in this study. The median age was 73 years (range 36-93 years). Of these, 41 patients (59%) were male. As for site of infections, catheter related blood stream infection was most frequently seen in 37 (53%). Seventeen patients (24%) were classified as participation possible group and 53 patients (76%) were participation impossible group. Comparing the two groups, participation possible group patients have much better performance status, have less comorbidities and have longer overall survival times than participation impossible group patients. CONCLUSION: Only 24% of candidemia patients were eligible for the clinical trials. Thus, we can see that clinical trials might not correctly reflect the real world among candidemia patients.

Efficacy and validity of automated quantitative chemiluminescent enzyme immunoassay for SARS-CoV-2 antigen test from saliva specimen in the diagnosis of COVID-19.

INTRODUCTION: The pandemic of a novel coronavirus disease 2019 (COVID-19) caused by a severe acute respiratory coronavirus 2 (SARS-CoV-2) infection has been problematic worldwide. A new SARS-CoV-2 antigen test (LUMIPULSEⓇ) was licensed and widely used in Japan since May 2020. We conducted this study intending to whether the automated quantitative CLEIA antigen test using a saliva sample is effective and valid for the diagnosis of COVID-19. PATIENTS AND METHODS: We analyzed and compared the diagnostic accuracy of both the automated quantitative CLEIA antigen test and real-time RT-PCR (rRT-PCR) using a saliva sample from individuals suspected as having COVID-19. RESULTS: A total of 305 samples were collected and tested in Aichi Medical University Hospital and affiliated facilities from December 2020 until January 2021 at our institute. Using reverse-transcription PCR as a reference, the AUROC of the automated quantitative CLEIA antigen test was 0.903 (95% confidential interval 0.845-0.962, p < 0.001). The appropriate cut-off antigen level was 4.0 pg/mL and had a sensitivity of 77.8%, a specificity of 99.6%, a positive predictive value of 98%, and a negative predictive value of 94.5%. On the other hand, the diagnostic accuracy of the antigen test decreased among patients among patients with COVID-19 with threshold cycle (Ct-value)≥27, which shows the AUROC was 0.795 (95%CI 0.687-0.907, p < 0.001). CONCLUSION: While the automated quantitative CLEIA antigen test from saliva specimen could be one of the most useful diagnostic tests for the diagnosis of COVID-19 in general practice, clinicians should know the limitations of the antigen test.

Usefulness of serum procalcitonin for necrotizing fasciitis as an early diagnostic tool.

INTRODUCTION: While the early diagnosis of necrotizing fasciitis (NF) is crucial and could lead to a favorable outcome, it is difficult to differentiate NF from cellulitis, resulting in delay for the appropriate treatment. PATIENTS AND METHODS: For the purpose of examining which diagnostic tools could correctly differentiate NF from cellulitis, we conducted this case-control study. We retrospectively reviewed all patients who were diagnosed with NF at our institute during 2014-2019. The patients who were diagnosed with cellulitis were randomly selected during the study period as the control group. The severity of NF is evaluated by serum-procalcitonin (PCT), LRINEC score, NTSI assessment and SIARI score. RESULTS: A total of 25 NF patients were enrolled in this study. The median age was 68 years (range 39-79) and 18 (72%) were male. Comparing NF and cellulitis groups, NF group showed a higher LRINEC score and serum PCT than cellulitis group did, even though there was no statistical significance in serum PCT. With respect to the diagnostic value for differentiating NF from cellulitis, the area under the ROC curve for of serum PCT and LRINEC scores were 0.928 [95% confidential interval (CI) 0.864-0.992, p < 0.001] and 0.846 (95% CI 0.757-0.936, p < 0.001). The appropriate serum-PCT cutoff value was 1.0 and had a sensitivity of 88%, a specificity of 89%, a positive predictive value of 81%, and a negative predictive value of 93%. CONCLUSION: Serum-PCT could be a useful diagnostic marker for differentiating diagnosis of NF from cellulitis.

Plasma procalcitonin levels remain low at the onset of gram-positive bacteremia regardless of severity or the presence of shock: A retrospective analysis of patients with detailed clinical characteristics.

OBJECTIVES: Procalcitonin (PCT) is an early diagnosis marker of sepsis/bacteremia. However, some reports refer to its lower responsiveness to gram-positive bacteremia. We retrospectively evaluated the PCT values at the onset of bacteremia in relation to severity index. METHODS: Patients with bacteremia caused by two gram-negative bacteria (46 E. coli and 50 Klebsiella pneumoniae) and three gram-positive bacteria (45 S. aureus, 56 S. epidermidis, and 10 S. mitis) were studied. The plasma PCT and C-reactive protein (CRP) levels were compared between species and different Sequential Organ Failure Assessment (SOFA) score groups. RESULTS: The median PCT level was higher in gram-negative than in gram-positive bacteremia in overall (13.09 vs. 0.50 ng/mL, p < 0.0001), in SOFA score≥4 group (28.85 vs.1.72 ng/mL, p < 0.0001) and in SOFA<4 group (2.64 vs. 0.42 ng/mL, p < 0.0001). Only 46%, and 11% of patients showed PCT ≥0.5 ng/mL in S. epidermidis, and S. mitis bacteremia, respectively. PCT was significantly better than CRP in discriminating gram-negative from gram-positive bacteremia (AUCROC; 0.828 and 0.634, p < 0.001), but it was low in Staphylococcus epidermidis bacteremia regardless of SOFA scores. CONCLUSIONS: PCT levels are lower in gram-positive bacteremia regardless of SOFA scores or the presence of shock. The conventional sepsis cutoff of 0.5 ng/mL may overlook certain proportions of gram-positive bacteremia.

The First Case of Community-Acquired Pneumonia Due to Capsular Genotype K2-ST86 Hypervirulent Klebsiella pneumoniae in Okinawa, Japan: A Case Report and Literature Review.

Hypervirulent Klebsiella pneumoniae (HV-KP) typically causes pyogenic liver abscess and bacteremia with metastatic infections. Community-acquired pneumonia (CAP) due to HV-KP is uncommon and details of its clinical and microbiological features are limited. We report the first case of CAP due to capsular genotype K2-ST86 HV-KP in Okinawa, Japan and review infections caused by the K2-ST86 strain. A 79-year-old woman presenting with fever and productive cough persisting for the past three days was admitted to hospital. Her vital signs indicated septic shock. Lung examination by auscultation revealed holo-crackle and lobar pneumonia in chest radiography, and Streptococcus pneumoniae was suspected. However, sputum and blood cultures revealed Gram-negative coccus identified as K. pneumoniae. Genetic analysis identified the isolated strain as the K2 serotype harboring rmpA, iutA, entB, and mrkD. Therefore, we identified the isolated strain as hypervirulent. The isolate belonged to ST86 as determined by multilocus sequence typing. The case was not complicated by predisposing factors such as diabetes mellitus and malignancy related to HV-KP infection; thus, this CAP-causing HV-KP strain may differ from the typical HV-KP strain that induces liver abscess. A literature review identified only nine cases with CAP due to HV-KP. In all cases, the disease mainly occurred in older males with diabetes mellitus, which makes the present case unusual, and had high rates of septic shock and death. No case, including ours, was complicated by metastatic infection, suggesting that CAP due to HV-KP poses little distant metastasis risk, even in patients with bloodstream infection. In our review, consistent with our case, K2-ST86 was the most common strain of HV-KP in patients with CAP. Therefore, studies are needed to elucidate the clinical and microbiological features of HV-KP CAP, with a focus on the K2-ST86 strain. Physicians should always consider K. pneumoniae in cases of sepsis CAP with lobar pneumonia.

Case Report of Primary Lung Abscesses Due to Hypervirulent Klebsiella pneumoniae (Serotype K2, Sequence Type 375): an Emerging Isolate in Okinawa, Japan.

Hypervirulent Klebsiella pneumoniae (HV-KP) is typically associated with community-acquired liver abscess and bacteremia with metastatic infection; however, primary lung abscess (PLA) caused by HV-KP is rare, with only one such case report to date. A 69-year-old man with a history of diabetes mellitus (DM) was admitted to hospital complaining of slight bloody sputum. Chest imaging showed multiple consolidations with cavities in both lung fields. A culture of bronchoalveolar lavage fluid confirmed the presence of K. pneumoniae. Genetic analyses identified the isolate as serotype K2 and sequence type 375 (K2-ST375), and that it harbored the rmpA gene. The patient was an Asian middle-aged male with DM, all of which are risk factors for HV-KP infection. Although complicating DM and the presence of the rmpA gene are more likely to induce disseminated infection, metastatic infections were not found in this patient. The clinical and microbiological characteristics of our patient were different from those of a previous reported case, although in both cases the patient was from Asia and had DM. Therefore, DM appears to be one of the predisposing factors for HV-KP lung abscesses and physicians should pay attention to emerging HV-KP lung abscess infection, particularly in Asian countries. Previous studies have also revealed that K2-ST375 is one of the major clones causing HV-KP infection, and that it is mainly isolated from patients with liver abscess. Interestingly, including the present case, most of the infectious cases caused by K2-ST375 have been reported from Okinawa Prefecture in Japan. Therefore, the trend of the K2-ST375 strain should be carefully monitored, particularly in Okinawa, Japan. The serotype of HV-KP that causes PLA is still unknown and further study is needed to elucidate the etiology of PLA due to HV-KP and the relationship between the strain K2-ST375 and PLA.

The SOFA score could predict the severity and prognosis of infective endocarditis.

INTRODUCTION: Although infectious endocarditis (IE) is a potentially severe infectious disease, there are no prognostic tools for in-hospital mortality for IE patients. This is the first report documenting that the Sequential Organ Failure Assessment (SOFA) score could evaluate the severity and outcome among IE patients. PATIENTS AND METHODS: From 2007 to 2018, we reviewed all patients who were diagnosed as having IE at our institue. Patients diagnosed as definite IE according to the modified Duke criteria or by surgical procedure were included in this study. RESULTS: A total of 66 IE patients were enrolled in this study. They were 45 males (68%) and the median age was 70 years. As for prognostic factors for in-hospital death among IE patients, SOFA score ≥6, CCI ≥3, surgical procedure, heart failure, immunological phenomena and detection of S. aureus as a causative pathogen were identified as prognostic factors by univariate analysis. Of these 6 factors, SOFA score ≥6 (OR 7.6, 95%CI 1.3-46.6, p = 0.029), heart failure (OR 9.7, 95%CI 1.1-86.1, p = 0.042), surgery (OR 0.1, 95%CI 0-0.8, p = 0.037) and immunological phenomena (OR 0.1, 95%CI 0-0.9, p = 0.042) were independent prognostic factors for in-hospital mortality among IE by logistic regression analysis. CONCLUSION: The SOFA score could be a good prognostic tool to use for IE patients. Also, SOFA score ≥6, surgery, immunological phenomena and heart failure were independent prognostic factors for in-hospital mortality among IE patients.

Brevibacterium paucivorans bacteremia: case report and review of the literature.

BACKGROUND: Brevibacteria are obligate aerobic gram-positive rods that are associated with milk products and are also found on human skin. Brevibacterium has been reported as a rare cause of catheter related blood steam infection mainly in immunocompromised hosts such as malignancies or AIDS patients. CASE PRESENTATION: A 94-year old woman, which had a past history of diabetes mellitus and chronic heart failure, presented with high fever associated with decreased oral intake and appetite loss and was admitted to our institute. A physical examination at the time of presentation was unremarkable. On day 2, both blood cultures collected on admission became positive with coryneform organism within 24 h without Staphylococci and Brevibacterium species were identified by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Subsequently, genetic investigation by 16S ribosomal RNA analysis was performed in order to identify the organism. Finally, the result identified this pathogen as Brevibacterium paucivorans with 99.5% homology on the Ez taxon database. The patient was started empirically on meropenem and teicoplanin for broad-spectrum antibiotic coverage. The patient's fever finally abated and labs were also improved. On day 14, the antibiotic therapy was discontinued. The site of infections was unknown. We hereby report a case of Brevibacterium paicivorans bacteremia in an immunocompetent patient and review cases of Brevibacterium specises bacteremia previously reported. This is the first case of B. paucivorans bacteremia as far as we could search. CONCLUSION: Physicians and microbiologists should be aware that Brevibacteria are uncommon but important agents which could cause opportunistic infections in immunocompetent.

Clostridioides difficile-related toxic megacolon after Cryptococcus neoformans cellulitis: A complex of two rare infections in an immunocompromised host.

A 76-year-old Japanese woman was admitted due to uncontrolled cellulitis of the right lower leg. She had deep vein thrombosis on the right limb. Moreover, she had a long history of rheumatoid arthritis treated with corticosteroids. Skin biopsy and lumbar puncture were performed to diagnose disseminated cryptococcosis. She was administered antifungal agents (liposomal amphotericin B and 5-fluorocytosine). On treatment day 14, debridement was performed, and cryptococcosis was controlled. However, she developed toxic megacolon due to Clostridioides difficile infection (CDI). On day 32, she was transferred to the intensive care unit due to severe acidosis and acute kidney injury secondary to CDI-related toxic megacolon. Vancomycin, metronidazole, and tigecycline were administered for treatment of CDI. After several weeks of intensive care, toxic megacolon was improved, but renal replacement therapy was discontinued according to the patient's will. On day 73, she died of renal failure. We experienced a complex of rare diseases, Cryptococcus neoformans cellulitis and Clostridioides difficile-related toxic megacolon. Both diseases were presumed to be the result of corticosteroid and methotrexate use. Hence, careful monitoring is required when treating immunocompromised hosts to reduce the risk of developing complications.

Rituximab Restores IFN-γ-STAT1 Function and Ameliorates Disseminated Mycobacterium avium Infection in a Patient with Anti-Interferon-γ Autoantibody.

A 67-year-old Japanese female with back pain and severe cachexia visited our hospital. The diagnosis was disseminated Mycobacterium avium complex infection (dMAC) with multiple bone involvement. Anti-mycobacterial chemotherapy was started, but fever persisted and dislocation of cervical vertebrae has made her bedridden. Because anti-interferon (IFN)-γ autoantibody was positive, four doses of rituximab 375 mg/m2, every 7 day, were administered. Soon after treatment, progression of osteolytic lesions and wasting has stopped. We proved that rituximab has recovered IFN-γ signaling as shown by IFN-γ-induced STAT1 phosphorylation. It can be a promising option for dMAC cases with anti-IFN-γ autoantibody.

Secondary organizing pneumonia following viral pneumonia caused by severe influenza B: a case report and literature reviews.

BACKGROUND: Some reported that organizing pneumonia (OP) may occur after influenza A infections including swine-origin influenza A (H1N1). However, OP associated with influenza B infection has never been reported. We report the first case of secondary OP associated with viral pneumonia caused by influenza B. CASE PRESENTATION: A 23-year old woman was diagnosed as viral pneumonia caused by type B influenza. Despite of antiviral therapy, abnormal chest shadows were not improved. Bronchoscopy and transbronchial lung biopsy showed organizing pneumonia due to viral pneumonia caused by influenza B. Corticosteroid therapy was started at 30 mg daily (0.5 mg/kg), and the dose was reduced to 25, 20, 15 or 10 mg per day every month with symptomatic and radiological resolution. Even after corticosteroid therapy was discontinued, we did not confirm disease recurrence. CONCLUSIONS: Physicians should be aware of the possibility for SOP and severe viral pneumonia even in case of type B as well as type A influenza infections.

The etiology and bacteriology of healthcare-associated empyema are quite different from those of community-acquired empyema.

OBJECTS: Changes in patients' background and life environment could contribute to increase healthcare-associated (HCA) empyema. There are no guidelines and statements for HCA empyema. METHODS: We retrospectively reviewed all patients with empyema who were admitted to the Aichi Medical University Hospital, Japan between 2008 and 2015. We evaluated patients' characteristics, microbial profiles, treatment and outcomes, and analyzed prognostic factors for 90-day mortality. RESULTS: A total of 48 patients were enrolled in this study. They were categorized into community-acquired (CA) empyema (16 patients) and healthcare-associated (HCA) empyema (32 patients). HCA empyema patients had higher Charlson comorbidity index (CCI) scores, and poorer performance status (PS) than CA empyema patients. Potentially-drug resistant (PDR) pathogens were seen more frequently in HCA empyema than in CA empyema. Compared with survival and death groups, the death group showed higher CCI scores and poorer PSs than the survival group. The death group had more malignancy than the survival group. PDR pathogens were detected more frequently in the death group than in the survival group. Multivariate analysis showed that emergence of PDR pathogens and malignancies were independent poor prognostic factors for 90-days mortality among empyema. CONCLUSION: The etiology and bacteriology of HCA empyema are quite different from those of CA empyema. Especially, the mortality of HCA empyema was higher than the one of CA empyema. Emergence of PDR pathogens in the pleural fluid detected by culture, pulmonary disease and malignancies were independent poor prognostic factors among CA and HCA empyema by multivariate logistic regression analysis.

Invasive pneumococcal disease caused by mucoid serotype 3 Streptococcus pneumoniae: a case report and literature review.

BACKGROUND: Among the different serotypes of Streptococcus pneumoniae, serotype 3 has received global attention. We report the fatal case of a 76-year-old Japanese man who had an invasive pneumococcal disease associated with pneumonia caused by serotype 3 S. pneumoniae. CASE PRESENTATION: The patient had a history of hypertension, laryngeal cancer, chronic obstructive pulmonary disease, and type 2 diabetes mellitus. Following a cerebral arteriovenous malformation hemorrhage, he underwent surgery to remove the hematoma and began rehabilitation. On day 66 of hospitalization, he suddenly developed a fever, and coarse crackles and wheezes were heard in his right lung. A diagnosis of hospital-acquired aspiration pneumonia was made, and initial treatment with piperacillin/tazobactam was started. Teicoplanin was added after S. pneumoniae was isolated from the blood culture, however, the patient died 5 days later. The S. pneumoniae detected in the sputum smear was serotype 3, showed mucoid colonies and susceptibility to penicillins, cephalosporins, carbapenems, and levofloxacin, but resistance to erythromycin. CONCLUSION: We experienced a fatal case of pneumonia caused by mucoid serotype 3 S. pneumoniae with a thick capsule. Serotype 3-associated pneumonia may develop a wider pulmonary infiltrative shadow, a prolonged therapeutic or hospitalization course, and a poor outcome. Careful observation and intervention are required, and the use of additional antibiotics or intravenous immunoglobulins should be considered in such cases. Pneumococcal immunization is also an important public health measure to minimize the development of severe infections caused by serotype 3 strains.

Bacteremia due to Citrobacter braakii: A case report and literature review.

Among the Citrobacter genus, the most commonly isolated bacteria from human specimens are Citrobacter freundii and Citrobacter koseri, and previous cases of infection due to Citrobacter braakii have been rarely reported. We present a case of bacteremia due to C. braakii in a 38-year-old woman with cervical cancer. She was admitted to our hospital with complaints of a fever, chills, and nausea. Blood culture results showed gram-negative bacilli identified as C. braakii via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis, although biochemical testing findings were suggestive of C. freundii. Since a rare pathogen was detected in the present case and the results of additional biochemical studies were suggestive of both C. braakii and Citrobacter farmeri, genetic analysis was conducted. Finally, the gram-negative bacilli were confirmed as C. braakii, a member of the C. freundii complex since 1993, by 16S ribosomal RNA gene sequencing analysis. The gastrointestinal tract was considered the portal of entry, because the patient had a rectal fistula and other cultures such as urine and vaginal discharge incubated species other than C. braakii. The patient recovered after receiving treatment with ciprofloxacin for 14 days. The epidemiology and clinical characteristics of C. braakii infection are still unknown because of the limitations in accurate identification by using currently available commercial biochemical testing and previously, only 6 cases of C. braakii infection have been reported. Physicians should focus on this species, because it causes community-acquired infections, although further studies are needed to clarify the clinical characteristics of C. braakii infections.