Journal of Infection and Chemotherapy最新文献

Erysipelothrix rhusiopathiae is a common zoonotic pathogen that rarely causes diseases in humans. It has three main disease manifestations: a localized cutaneous, a disseminated cutaneous, and a systemic form of infection, typically characterized as bacteremia with or without endocarditis. Human infections are often associated with occupational exposure to animals, animal products, or their excreta. We present a case of a 60-year-old woman found to have E. rhusiopathiae bacteremia associated with a leg laceration sustained after she fell into a sewer drain. Germane animal exposures were not identified; thus, the source of bacterium was attributed to sewage or sewage-contaminated water. She was initially treated with intravenous penicillin with clinical improvement. However, given the patient's social factors, prolonged oral antimicrobial therapy was considered. E. rhusiopathiae is routinely susceptible to penicillin, cephalosporins, and fluoroquinolones but resistant to vancomycin. The data on alternatives to beta-lactam therapy are limited. We report a case of E. rhusiopathiae bacteremia successfully treated with oral linezolid.

Introduction: The bacterium Corynebacterium urealyticum produces urease and can cause encrusted pyelitis, a condition characterized by calcifications of the renal pelvis and ureteral wall, which may obstruct the urinary tract. We describe a case of encrusted pyelitis caused by C. urealyticum in a kidney transplant patient presenting with altered consciousness due to hyperammonemia.

Case presentation: An 81-year-old woman with a history of cadaveric kidney transplantation, thirty years prior, presented with acute altered consciousness during hospitalization. Laboratory findings showed acute renal failure and hyperammonemia, and urinalysis revealed high pH (>9.0) and pyuria. Abdominal non-contrast computed tomography revealed calcification of the renal pelvis and hydronephrosis. C. urealyticum was isolated from both blood and urine cultures. A diagnosis of encrusted pyelitis and hyperammonemia caused by C. urealyticum was made, and intravenous vancomycin was administered. Following the initiation of vancomycin and the temporary hemodialysis, her hyperammonemia and altered consciousness rapidly improved. Treatment with vancomycin resulted in a reduction of the urinary tract encrustation.

Conclusion: This case highlights C. urealyticum as a urinary pathogen that can lead to encrusted pyelitis, hyperammonemia, and altered consciousness in renal transplant patients.

Background: A nationwide survey conducted by the Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases in 2020 provided insights into antimicrobial prescription practices among clinic doctors. This study aimed to investigate factors influencing changes in antimicrobial prescriptions post-implementation of the National Action Plan on Antimicrobial Resistance (NAPAR) and doctors' inclination to prescribe antimicrobials for common cold cases.

Methods: In September 2020, randomly selected questionnaires were distributed to 3000 community-based medical clinics in Japan. The primary objective was to assess the reduction in antimicrobial prescriptions post-NAPAR implementation. Multivariate linear regression analysis was employed to identify associated factors.

Results: Analysis of 632 responses (response rate: 21.1 %) revealed determinants of decreased antimicrobial prescriptions, including familiarity with the Guide to Antimicrobial Stewardship (β = .482, t = 3.177, p = 0.002) and awareness of NAPAR (β = .270, t = 2.301, p = 0.022).

Conclusion: Interventions such as the Guide to Antimicrobial Stewardship may have contributed to the reduction in antimicrobial prescriptions among Japanese physicians. However, targeted strategies are needed to address high-prescription groups. Enhancing awareness and education on appropriate antimicrobial use should be integral components of future initiatives to combat antimicrobial resistance effectively.

Mycobacterium bovis is one of the species belonging to the Mycobacterium tuberculosis complex; its attenuated form-Bacillus Calmette-Guérin (BCG)-is used as a live vaccine against tuberculosis. Besides its use as a vaccine, BCG is widely used for treating bladder cancer. However, complications related to its use can lead to disseminated infection with M. bovis, known as BCGosis. BCGosis has multiple manifestations, and its culture requires a long time and complex polymerase chain reaction (PCR), posing challenges to its diagnosis. Herein, we report a case of a 74-year-old man with bladder cancer in whom multiple new arterial aneurysms developed during spondylitis treatment following intravesical BCG administration. The patient presented with syncope and left neck swelling. His medical history included transurethral bladder tumor resection and intravesical BCG therapy for bladder cancer. Sixteen months before he visited our institution, he developed spondylitis (L5/S1), an epidural abscess (L5/S1), and an abscess on the right thigh. Biopsy cultures and PCR confirmed M. tuberculosis complex, leading to antituberculosis drug therapy. Upon admission, multiple aneurysms were identified, and drug therapy was continued. However, new multiple aneurysms developed with the rupture of the right femoral aneurysm, leading to surgical interventions and arterial biopsy. The biopsy showed no signs of mycobacterial infection. Other aneurysm etiologies were ruled out and M. bovis was confirmed by PCR in the specimen from the initial intervertebral disc biopsy; thus, a diagnosis of BCGosis was made. This case highlights the importance of a thorough follow-up to detect new complications, even during treatment.

Background: Prolonged installation of a nephrostomy tube causes colonization of various microorganisms within the lumen of the tube, leading to the development of nephrostomy tube-associated pyelonephritis (NTAP). Patients with malignancy, often necessitating long-term installation of a nephrostomy tube, are susceptible to NTAP. However, information regarding the characteristics of NTAP in this population is limited.

Methods: We reviewed 43 NTAP cases of patients with malignancy in a cancer center and examined causative and non-causative microorganisms among those detected in urine culture. Causative microorganisms were defined as (1) those detected simultaneously in urine and blood cultures or (2) those detected in monomicrobial urine culture and to which physicians administered active antimicrobials for ≥5 days. Non-causative microorganisms were defined as those to which active antimicrobials were given for a total of <5 days.

Results: Patients in 42 of the 43 NTAP cases recovered with antimicrobial therapy for ≥7 days. Causative microorganisms were identified in 25 cases, where Escherichia coli and Klebsiella pneumoniae were most frequent. All enterococci other than Enterococcus faecalis, Corynebacterium species, and Candida species other than Candida albicans and most of Stenotrophomonas maltophilia detected in urine culture were considered non-causative of NTAP.

Conclusion: E. coli was a common organism causing NTAP of this population. Several microorganisms resistant to cephalosporin were non-causative of NTAP, for which administration of antimicrobials may be unnecessary even if detected in urine culture.

Introduction: Teicoplanin (TEIC) is typically administered as a loading dose over 36-48 h. Achieving an effective concentration quickly is expected to treat severe infections, such as sepsis and methicillin-resistant Staphylococcus aureus infections. We aimed to identify the TEIC loading dose to be completed within 24 h, targeting the concentration of 15-30 μg/mL and factors affecting the loading dose by utilizing the decision tree (DT) model.

Methods: Patients treated with TEIC between January 2017 and December 2022 who met the 24-h loading dose regimen were enrolled. A LD_22.5 (corrected TEIC loading dose targeting concentration of 22.5 μg/mL) was determined, factors affecting the concentration were extracted, and a DT model was constructed. The validity of the DT was assessed using the coefficient of determination (R²) in the DT and population pharmacokinetics (PopPK) models for LD_22.5.

Result: A total of 149 patients were divided into training (n = 104, 70 %) and test groups (n = 45, 30 %). We indicated an average of 14.5 mg/kg for LD_22.5 and extracted four factors (estimated glomerular filtration rate, age, albumin, and C-reactive protein) from the DT model. The R² values were 0.724, 0.695, 0.681, and 0.653 for the DT models (training and test groups) and two PopPK models, respectively.

Conclusion: We established a 24-h loading dose regimen targeting the TEIC concentration of 15-30 μg/mL and identified four factors affecting the loading dose by using DT. By following the indicated DT algorithm flowchat, optimal decisions regarding the loading dose could be made for TEIC therapy.

Cryptococcus neoformans is an environmental fungus that can frequently cause life-threatening meningitis and fungemia in acquired immunodeficiency syndrome patients. In recent years, cases of these fungal infections are increasingly identified in HIV-negative patients especially in solid organ transplantation (SOT) patients. Cryptococcal fungemia can often clinically present as life-threatening disseminated disease from subclinical colonization. This is a factor that affects survival, especially in patients with decompensated liver cirrhosis and SOT recipients. Early diagnosis and appropriate treatment are important for the course of the disease. This report describes the cryptococcal fungemia that developed in an HIV-negative patient after SOT due to alcohol-related liver cirrhosis.

We report a rare case of bacteremia with concomitant acute transverse myelitis (ATM) without evidence of a primary infectious focus or secondary localization due to Staphylococcus aureus in a 60-year-old man admitted for hyperpyrexia, quadriplegia, and respiratory failure. Bacterial ATM is a rare clinical entity with confusing clinical presentation and challenging diagnosis; isolated bacterial infections of the spinal cord without secondary localization or contiguous foci are exceptionally rare, as is S. aureus as the cause of infection. In this case, a rapid etiologic diagnosis was made possible by close collaboration between clinicians, infectious disease specialists and clinical microbiologists combined with extended molecular testing on CSF guided by incoming results.

Purpose: This study aimed to clarify the epidemiology and clinical features of tick bites in a Japanese spotted fever (JSF)-endemic area.

Method: The clinical records of patients with tick bites were retrospectively reviewed based on a survey conducted at Numakuma Hospital, Fukuyama City, Hiroshima, Japan, from 2016 to 2023. Data on basic characteristics, visit dates, residential address, exposure activities, tick-bite sites, and prophylactic antimicrobial prescriptions for each patient with tick bites were collected at the JSF hotspot hospital.

Results: A total of 443 patients with tick bites visited the hospital, of which data on 305 cases (68.8 %) were reviewed. The median age of these patients was 71 years, with a higher proportion of women (63.0 %). One-third of the patients had a preceding history of working in fields, whereas two-thirds had entered mountains or agricultural fields. Nearly 90 % of the patients visited the hospital from April to August, and the most common bite sites were the lower extremities (45.1 %). Most patients (76.1 %) resided in the southern area of Numakuma Hospital. Nearly all patients were prescribed prophylactic antibiotics (minocycline in 87.8 % of cases), and none subsequently developed JSF.

Conclusion: Continued surveillance of patients with tick bites is warranted to better understand changes in the clinical impact of tick-borne diseases.

Introduction: Sulfamethoxazole/trimethoprim (ST) is a first-line drug for preventing pneumocystis pneumonia (PCP). Several small-scale studies have suggested the usefulness of the low-dose regimen of ST (200/40 mg/day) over the standard-dose one (400/80 mg/day). Thus, this study aimed to investigate the efficacy and safety of low-dose and standard-dose regimens of ST in preventing PCP in patients with non human immunodeficiency virus infection using a large-scale electronic medical record database.

Methods: This retrospective study included patients who received ST prophylaxis for PCP registered in the RWD database between June 2007 and February 2023. Patients received either standard-dose (400/80 mg/day) or low-dose (200/40 mg/day) regimen groups. The incidence of cases initiated PCP therapeutic dose (ci-PCPTD) (ST ≥ 3600/720 mg/day) and adverse events (AEs) was evaluated, and risk factors for ci-PCPTD were investigated.

Results: A total of 11,384 patients received the standard-dose, whereas 7973 received the low-dose regimen groups. No significant difference in the cumulative incidence of ci-PCPTD was observed between the standard-dose (0.67%) and low-dose regimen group (0.47%). Lung disease was a significant risk factor for ci-PCPTD. The cumulative incidence of ci-PCPTD in patients with acute exacerbation of interstitial pneumonia was 1.3% in both groups, and no significant difference was observed between the two groups. The low-dose regimen group had a lower incidence of all AEs than the standard-dose regimen group.

Conclusion: These results based on a large-scale electronic medical record database provide important evidence supporting the clinical significance of low-dose regimen of ST.