A case of prosthetic valve endocarditis and aortic abscess due to Bacillus cereus.

Bacillus cereus (B. cereus) is commonly found in the environment and is often considered a blood culture contaminant. However, in patients with specific risk factors such as intravenous drug use, central venous access catheters, immunosuppression, or prosthetic valves, B. cereus can cause severe infections. Herein, we present a case of prosthetic valve endocarditis (PVE) caused by B. cereus in an 84-year-old woman with a history of aortic valve replacement for aortic stenosis five years earlier. She presented with anorexia, and her physical examination revealed tenderness in the left upper quadrant of the abdomen. Blood culture grew B. cereus, and a CT scan showed splenic infarction, raising suspicion of PVE. Transesophageal echocardiogram (TEE) revealed an abscess around the left coronary cusp of the aortic valve and a 15 mm vegetation. Due to the patient's high risk for post-operative complications and her unwillingness to undergo surgery, the surgery was deferred. Instead, she was successfully treated with six weeks of intravenous vancomycin and discharged home. Follow-up TEE demonstrated resolution of the vegetation and valvular abscess. At her six-month post-discharge evaluation, no signs of active infection were noted including fever or worsening heart failure. Although surgery is typically recommended for most cases of PVE, conservative treatment can be considered as an alternative option for selected patients.

Clinical and microbiological characteristics of Ruminococcus gnavus bacteremia and intra-abdominal infection.

OBJECTIVES: Ruminococcus gnavus is a rare human pathogen, and clinical data on R. gnavus infection are insufficient. This retrospective study aimed to investigate the clinical characteristics of R. gnavus infections. METHODS: This study included 13 cases of bacteremia and three cases of non-bacteremia infections caused by R. gnavus. We evaluated the patient data, infection source, clinical outcomes, and antimicrobial susceptibility of R. gnavus isolates for these cases. RESULTS: The median age of patients was 75 years (range 47-95), and eight patients were female. Twelve cases were presumed to have an intra-abdominal infection source, and the remaining four cases had an unknown infection source. The most common underlying conditions were immunosuppression (seven cases), solid tumors (seven cases), and history of gastrointestinal surgery (five cases). Thirteen patients exhibited gastrointestinal problems (dysfunction, bleeding, intra-abdominal infection, or inflammation). Multiple pathogens were observed in six cases, and fatal outcomes were recorded in three cases. Antimicrobial susceptibility data were available for eight isolates, all of which exhibited low minimum inhibitory concentrations to penicillin (≤0.03 µg/mL), ampicillin-sulbactam (≤0.5 µg/mL), piperacillin-tazobactam (≤4 µg/mL), and metronidazole (≤0.5-1 µg/mL). CONCLUSION: Ruminococcus gnavus is frequently associated with an intra-abdominal infection source, and treatment strategies should consider the possibility of multiple pathogens.

Effectiveness of primary series, first, and second booster vaccination of monovalent mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections and severe diseases during the SARS-CoV-2 omicron BA.5 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS).

BACKGROUND: This study aimed to evaluate VE of primary, first, and second booster ancestral-strain monovalent mRNA COVID-19 vaccination against symptomatic infections and severe diseases in Japan. METHODS: We conducted a test-negative case-control study. We included medically attended episodes and hospitalizations involving individuals aged ≥16 with signs and symptoms from July to November 2022, when Omicron BA.5 was dominant nationwide. To evaluate VE, we calculated adjusted ORs of vaccination among test-positive versus test-negative individuals using a mixed-effects logistic regression. RESULTS: For VE against symptomatic infections among individuals aged 16 to 59, VE of primary vaccination at > 180 days was 26.1% (95% CI: 10.6-38.8%); VE of the first booster was 58.5% (48.4-66.7%) at ≤90 days, decreasing to 41.1% (29.5-50.8%) at 91 to 180 days. For individuals aged ≥60, VE of the first booster was 42.8% (1.7-66.7%) at ≤90 days, dropping to 15.4% (-25.9-43.2%) at 91 to 180 days, and then increasing to 44.0% (16.4-62.5%) after the second booster. For VE against severe diseases, VE of the first and second booster was 77.3% (61.2-86.7%) at ≤90 days and 55.9% (23.4-74.6%) afterward. CONCLUSION: mRNA booster vaccination provided moderate protection against symptomatic infections and high-level protection against severe diseases during the BA.5 epidemic in Japan.

Clinical Features, Genome Epidemiology, and Antimicrobial Resistance Profiles of Aeromonas spp. Causing Human Infections: A Multicenter Prospective Cohort Study.

Background: The genus Aeromonas is increasingly implicated in human infections, but knowledge of its clinical characteristics and antimicrobial resistance profiles has been limited owing to its complex taxonomy. Methods: We conducted a multicenter prospective cohort study of patients with Aeromonas infections at hospitals across Japan. Patients were eligible for inclusion if they had an Aeromonas spp. strain in a clinical culture and were considered infected at the culture site. Clinical data were collected, and isolates underwent susceptibility testing and whole-genome sequencing. Results: A total of 144 patients were included. Hepatobiliary infection accounted for a majority of infections (73% [105 of 144]), which mostly occurred in elderly patients with comorbid conditions, including hepatobiliary complications. The all-cause 30-day mortality rate was 10.0% (95% confidence interval, 4.9%-14.8%). By whole-genome sequencing, 141 strains (98%) belonged to 4 Aeromonas species-A caviae, A hydrophila, A veronii, and A dhakensis-with significant intraspecies diversity. A caviae was predominant in all infection sites except skin and soft tissue, for which A hydrophila was the prevailing species. The genes encoding chromosomally mediated class B, C, and D ß-lactamases were harbored by 92%-100% of the isolates in a species-specific manner, but they often lacked association with resistance phenotypes. The activity of cefepime was reliable. All isolates of A hydrophila and A dhakensis carried an mcr-3-like colistin resistance gene and showed reduced susceptibility to colistin. Conclusions: Hepatobiliary tract was the most common infection site of Aeromonas spp., with A caviae being the dominant causative species. The resistance genotype and phenotype were often incongruent for ß-lactam agents.

Nationwide Descriptive Epidemiological Study of Patients with COVID-19 Evacuated from Wuhan, China to Japan from January to February, 2020.

We investigated the epidemiological findings regarding the route of coronavirus disease 2019 (COVID-19) and infection prevention and control (IPC) measures among returnees in the emergency evacuation from Wuhan, China to Japan during the COVID-19 outbreak in 2020. A total of 12 of the 14 returnees (median age [range]: 49.5 years [29-65 years]; 9 men [75%]) had confirmed COVID-19. The proportion of returnees with COVID-19 was 12/566 (2.1%) in Flights 1-3 and 2/263 (0.8%) in Flights 4 and 5. Six patients were asymptomatic on admission, while 3 patients developed symptoms thereafter. None of the participants reported a specific history of contact with animals, going to seafood markets, or visiting medical facilities. Two patients were in contact with an individual who was confirmed or suspected of having COVID-19. Most patients resided in hotels in the center of Wuhan City, taking taxis and trains for commute. Patients relatively adhered to IPC measures such as wearing a mask and hand hygiene. However, emphasis on IPC measures such as universal masking and more rigorous avoidance of exposure risk might have been necessary to prevent infection. In addition, forced social distancing due to lockdown might have contributed to the lower infection rates in Flights 4 and 5, compared to Flights 1-3.

Time to positivity of Corynebacterium in blood culture: Characteristics and diagnostic performance.

The presence of Corynebacterium in blood samples can indicate true bacteremia or contamination, thus complicating the diagnosis of true bacteremia. We aimed to evaluate the usefulness of time to positivity (TTP) in diagnosing true bacteremia and contamination in cases where Corynebacterium was isolated from blood samples. We compared the TTP of the true-bacteremia group (n = 77) with that of the contamination group (n = 88). For the true-bacteremia cases that had only one set of positive blood cultures (n = 14), considering clinical and bacteriological data, additional cultures were performed on blood or other specimens. The same Corynebacterium spp. as in blood were isolated from these specimens. Receiver operating characteristic curves were generated, and the sensitivity and specificity of TTP were calculated for diagnosing true bacteremia. The median TTP of the true-bacteremia group (26.8 h) was shorter than that of the contamination group (43.3 h) (P < 0.0001). When considering TTP ≤ 25.0 h as true bacteremia, the sensitivity and specificity were 44.2% and 95.5%, respectively. Moreover, when considering TTP ≤ 69.4 h as true bacteremia, the sensitivity and specificity were 96.1% and 20.5%, respectively. Among the true-bacteremia groups with one set of positive blood cultures (n = 14), no case exhibited a TTP > 69.4 h. Only three cases showed TTP ≤ 25.0 h in the true-bacteremia group with one set of positive blood cultures. TTP > 69.4 h is likely to indicate contamination and may be useful to exclude true bacteremia in cases with one set of positive blood cultures. Meanwhile, diagnosing true bacteremia using the threshold of TTP 25.0 h would be difficult. Therefore, the clinical and bacteriological data are important for diagnosing bacteremia, especially in cases with TTP ≤ 69.4 h.

Catheter-related bloodstream Mycobacterium wolinskyi infection in an umbilical cord blood transplant recipient: a case report.

BACKGROUND: Catheter-related bloodstream infection (CRBSI), caused by rapidly growing mycobacteria (RGM), is a rare infectious complication in hematopoietic stem cell transplant (HSCT) recipients and can often be misdiagnosed as Gram-positive rod (GPR) bacteremia. CASE PRESENTATION: We present a case of CRBSI caused by Mycobacterium wolinskyi, a rare RGM, in a 44-year-old female patient who received an umbilical cord blood transplant. CONCLUSIONS: Rapidly growing mycobacteria can stain as GPRs and may grow in routine blood culture media after 3-4 days of incubation. These features are not widely known to clinicians, and acid-fast staining is therefore recommended when unidentifiable GPRs are detected in blood cultures, especially in immunocompromised patients, such as those with hematologic malignancies or intravascular devices.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020).

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Early diagnosis of Cryptococcus neoformans var. grubii meningitis using multiplex PCR assay in an immunocompetent patient.

Cryptococcosis is an invasive fungal infection that mainly affects the lungs and central nervous system. While patients with cell-mediated immunodeficiency are at high risk of developing cryptococcosis, there have been increasing reports of cryptococcosis in immunocompetent individuals with no underlying conditions. Herein, we report a case of cryptococcal meningitis in a 55-year-old apparently immunocompetent man with a history of heavy alcohol consumption. Although the patient was initially treated for tuberculous meningitis and varicella-zoster virus induced vasculopathy due to a history of exposure to tuberculosis and a presence of stroke, a multiplex polymerase chain reaction (PCR) assay of cerebrospinal fluid (CSF) identified Cryptococcus species unexpectedly, enabling swift treatment and a favorable clinical outcome. The multiplex PCR assay, which can identify multiple pathogens simultaneously and instantly, may lead to early diagnosis and treatment by detecting unanticipated pathogens. Furthermore, the strain was identified through multilocus sequence typing (MLST) analysis as Cryptococcus neoformans var. grubii, Sequence Type 5, molecular type: VNI. Although simplified microbial identification techniques such as mass spectrometry have recently been developed, molecular biological assays are still essential for the accurate identification of infectious strains.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020).

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members.As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

SARS-CoV-2 Screening Test for Japanese Returnees From Wuhan, China, January 2020.

BACKGROUND: Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) was found to be the causative microorganism of coronavirus disease 2019 (COVID-19), which started to spread in Wuhan, China. This study was to evaluate the effectiveness of questionnaire, symptoms-based screening, and polymerase chain reaction (PCR) screening of returnees from COVID-19-endemic areas on a chartered flight, to examine the proportion of infected persons and the proportion of asymptomatic persons among infected persons who returned from Wuhan. METHODS: A retrospective cohort study was done in 7 tertiary medical institutions in Japan. A total of 566 Japanese who returned from Wuhan participated in the study. RESULTS: Overall, 11 of the 566 passengers had a positive SARS-CoV-2 PCR result for pharyngeal swabs and 6 were asymptomatic. Only fever differed between SARS-CoV-2-positive and -negative individuals (P < .043). Six of the 11 PCR-positive individuals were asymptomatic; 4 remained positive on day 10, and 1 asymptomatic person tested positive up to day 27. Two of the 11 were negative on the first PCR test and positive on the second. CONCLUSIONS: Our results will be important insights on screening returnees from locked-down cities, as well as providing important data on the proportion of asymptomatic individuals infected with SARS-CoV-2. A 13-day observation period and a second round of PCR may be effective to screen patients, including asymptomatic infections.

The First Report of Calcified Amorphous Tumor Associated with Infective Endocarditis: A Case Report and Review of Literature.

BACKGROUND Calcified amorphous tumor (CAT) of the heart is a rare non-neoplastic intracardiac mass, which is composed of calcium deposition surrounded by amorphous fibrous tissue. The clinical presentation of cardiac CAT resembles that of other cardiac tumors or vegetation, though there is no previous report of a CAT complicated with infective endocarditis. CASE REPORT A 67-year-old male with a history of end stage renal failure and gastric cancer who was on adjuvant chemotherapy presented with a cardiac mass. The mass was resected and diagnosed as CAT pathologically. Two separate sets of blood cultures were positive for Enterococcus faecalis, thus, the patient was diagnosed with infective endocarditis. Antibiotic treatment was continued for 6 weeks after surgery, and the patient recovered uneventfully. However, he died from a complication of his gastric cancer 5 months later. CONCLUSIONS This is the first report of CAT associated with infective endocarditis. Blood cultures should be obtained to differentiate infective endocarditis or CAT with infectious endocarditis from CAT alone, because CAT with infective endocarditis may present atypically and may be more likely to require antibiotic treatment along with surgery.

Review of the first comprehensive outpatient parenteral antimicrobial therapy program in a tertiary care hospital in Japan.

OBJECTIVES: The infectious diseases team at Kameda Medical Center, Japan, implemented a new outpatient parenteral antimicrobial therapy (OPAT) program in July 2012 and expanded the program with the support of home care services. This study reviews the OPAT program after 5.5 years of operation. METHODS: We prospectively collected data about the age, sex, diagnoses, causative organisms, types of OPAT, modes of administration, selected antibiotics, treatment durations, bed days saved, outcomes, readmissions, and estimated cost reductions of all patients who were treated in the OPAT program from July 2012 to December 2017. RESULTS: Of the 66 patients treated under the OPAT program, 45 (68.2%) were treated using clinic OPAT, and 21 (31.8%) were treated using homecare OPAT. The most commonly targeted organism was methicillin-susceptible Staphylococcus aureus. Continuous infusion with elastomeric pumps was employed in 55 patients (83.3%). Cefazolin was the most frequently used antibiotic (39.4%), followed by penicillin G (24.2%). The median OPAT duration was 13 days (range, 3-51), and the total bed days saved was 923. The estimated medical cost reduction was approximately 87,000 US dollars. CONCLUSIONS: Our experience shows that OPAT is a safe and feasible practice not only for efficient bed utilization and medical cost savings but also for better antimicrobial stewardship.

Significant Species Differences in Intestinal Phosphate Absorption between Dogs, Rats, and Monkeys.

A treatment for hyperphosphatemia would be expected to reduce mortality rates for CKD and dialysis patients. Although rodent studies have suggested sodium-dependent phosphate transporter type IIb (NaPi-IIb) as a potential target for hyperphosphatemia, NaPi-IIb selective inhibitors failed to achieve efficacy in human clinical trials. In this study, we analyzed phosphate metabolism in rats, dogs, and monkeys to confirm the species differences. Factors related to phosphate metabolism were measured and intestinal phosphate absorption rate was calculated from fecal excretion in each species. Phosphate uptake by intestinal brush border membrane vesicles (BBMV) and the mRNA expression of NaPi-IIb, PiT-1, and PiT-2 were analyzed. In addition, alkaline phosphatase (ALP) activity was evaluated. The intestinal phosphate absorption rate, including phosphate uptake by BBMV and NaPi-IIb expression, was the highest in dogs. Notably, urinary phosphate excretion was the lowest in monkeys, and their intestinal phosphate absorption rate was by far the lowest. Dogs and rats showed positive correlations between Vmax/Km of phosphate uptake in BBMV and NaPi-IIb expression. Although phosphate uptake was observed in the BBMV of monkeys, NaPi-IIb expression was not detected and ALP activity was low. This study revealed significant species differences in intestinal phosphate absorption. NaPi-IIb contributes to intestinal phosphate uptake in rats and dogs. However, in monkeys, phosphate is poorly absorbed due to the slight degradation of organic phosphate in the intestine.

Patient with liver cirrhosis presenting with necrotizing fasciitis due to Acinetobacter junii: A case report and literature review.

Acinetobacter spp. are known to be a cause of nosocomial infections and to have diverse mechanisms of resistance to antimicrobials. Here, we report the case of a patient who presented to our emergency department with necrotizing fasciitis due to Acinetobacter junii as confirmed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS). Patients with liver cirrhosis are susceptible to gram-negative infection. Moreover, although Acinetobacter spp. infection is best known to be a cause of combat-related-skin and soft-tissue infections, we propose that medical professionals need to consider the presence of these potentially multi-drug-resistant, gram-negative pathogens when treating patients with liver cirrhosis who present with severe soft-tissue infections. To our knowledge, this is the first case report of severe-skin and soft-tissue infections caused by A. junii.

Chorea-like symptoms and high blood concentration of ceftriaxone in a patient undergoing hemodialysis: A case report.

Ceftriaxone (CTRX) is a third-generation cephalosporin commonly used to treat infections such as community-acquired pneumonia and urinary tract infections caused by mainly Gram-negative bacteria and some Gram-positive bacteria. Here, we report a case of a patient on hemodialysis who had chorea-like symptoms with high blood concentration of CTRX. A 74-year-old Japanese woman receiving hemodialysis was admitted with obstructive cholangitis and was started on CTRX therapy at a dose of 2 g every 24 hours. On the 6th day after starting administration of CTRX, chorea-like symptoms appeared. We suspected that her symptoms were caused by a high blood concentration of CTRX. We performed a series of blood sampling to determine the concentration of CTRX at different time points before and after discontinuing CTRX administration. CTRX concentrations were higher than those expected in healthy adults, and her chorea-like symptoms had disappeared from the second day of discontinuation of CTRX. The association between CTRX blood concentration and chorea-like symptoms is unclear. However, measuring a series of plasma or serum concentrations from symptom onset to disappearance suggested that chorea-like symptoms appeared when the concentration exceeded approximately 450 µg/mL. Care should be taken when administering CTRX to patients with cholestasis undergoing hemodialysis, as blood CTRX levels may rise unexpectedly and result in complications.

Ceftriaxone versus ampicillin/sulbactam for the treatment of aspiration-associated pneumonia in adults.

Aim: To compare hospital mortality in patients with aspiration-associated pneumonia treated with ceftriaxone (CTRX) and in those treated with ampicillin/sulbactam (ABPC/SBT). Methods: From a Japanese multicentre observational study cohort of patients with pneumonia, those diagnosed with pneumonia and having at least one aspiration-related risk factor were selected. Propensity score-matching analysis was used to balance baseline characteristics of the participants and compare hospital mortality of patients treated with CTRX and those treated with ABPC/SBT. Results: Hospital mortality did not significantly differ between patients treated with CTRX and those treated with ABPC/SBT (6.6 vs 10.7%, risk difference -4.0, 95% CI [-9.4, 1.3]; p = 0.143). Conclusion: Further studies are needed to compare CTRX and ABPC/SBT treatments in patients with aspiration-associated pneumonia.