Cholangitis with bacteremia due to Pseudomonas nitroreducens in a patient with pancreatic neuroendocrine tumors: a case report.

BACKGROUND: Pseudomonas nitroreducens is a non-fermenting, gram-negative, rod-shaped bacterium commonly inhabiting soil, particularly soil contaminated with oil brine. To our knowledge, no cases of human infection with P. nitroreducens have been previously reported. Here, we present the first documented case of cholangitis caused by P. nitroreducens in a patient with bacteremia. CASE PRESENTATION: A 46-year-old Japanese man with an advanced pancreatic neuroendocrine tumor was hospitalized with fever and chills. Four days before admission, the patient developed right upper abdominal pain. Two days later, he also experienced fever and chills. Endoscopic retrograde cholangiopancreatography was performed on the day of admission, and the patient was diagnosed as having cholangitis associated with stent dysfunction. Gram-negative rods were isolated from blood cultures, but attempts to identify the bacteria using VITEK2 and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with VITEK MS ver. 4.7.1 (bioMérieux Japan Co. Ltd., Tokyo, Japan) were unsuccessful. Finally, the organism was identified as P. nitroreducens using MALDI-TOF MS with a MALDI Biotyper (Bruker Daltonics Co., Ltd., Billerica, MA, USA) and 16 S ribosomal RNA sequencing. Despite thorough interviews with the patient, he denied any exposure to contaminated soil. The patient was treated with intravenous cefepime and oral ciprofloxacin for 16 days based on susceptibility results, achieving a good therapeutic outcome. At the outpatient follow-up on day 28, the patient was in good general condition. CONCLUSIONS: This is the first reported human case of cholangitis with bloodstream infection caused by P. nitroreducens. This report provides clinicians with novel insights into the clinical manifestations and diagnostic methods necessary for the accurate diagnosis of P. nitroreducens, along with guidance on treatment.

Pyelonephritis with bacteremia caused by Salmonella Choleraesuis in a Japanese patient with carcinoma of unknown primary origin: A case report.

Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) is a nontyphoidal Salmonella pathogen that causes swine paratyphoids. S. Choleraesuis is a zoonotic pathogen transmitted to humans via contaminated food and causes sepsis. Here, we report a rare case of pyelonephritis caused by S. Choleraesuis in a Japanese patient with a carcinoma of unknown primary origin. On the day of admission, the patient was diagnosed with pyelonephritis associated with ureteral stent obstruction. He had no history of raw pork consumption or gastrointestinal symptoms. Gram-negative rods were isolated from urine and blood cultures, identified as Salmonella enterica subsp. enterica using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The serological typing results were O7: -: 1 and 5; however, the serotypes could not be determined. The isolate was identified as S. Choleraesuis using multilocus sequence typing, nucleotide sequence analysis of the fliC gene, and biochemical examination. Four days after a 14-day course of intravenous piperacillin-tazobactam (9 g/day), the patient showed relapse of the condition. Subsequently, the patient was treated with intravenous ceftriaxone (2 g/day) and oral amoxicillin (1000 mg/day) for 14 days each; recurrence was not observed. This novel case of pyelonephritis with bacteremia was caused by S. Choleraesuis in Japan. Conventional testing methods could not identify the serotypes; however, the case highlights the importance of adopting advanced diagnostic techniques based on molecular biology to ensure accurate pathogen identification.

Bacillus subtilis variant natto Bacteremia of Gastrointestinal Origin, Japan.

We report a case of bacteremia caused by Bacillus subtilis variant natto after a gastrointestinal perforation in a patient in Japan. Genotypic and phenotypic studies of biotin identified B. subtilis var. natto. This case and 3 others in Japan may have been caused by consuming natto (fermented soybeans).

A pediatric case of Gordonia otitidis bacteremia detected by long-term blood culture.

For immunocompromised patients receiving chemotherapy or bone mallow transplantation, slow-growing bacteria should also be considered one of the pathogenic microorganisms. However, there is no evidence pertaining to the microbiological tests associated with a patient with febrile neutropenia before peripheral blood stem cell harvest (PBSCH). We report a case of a 4-year-old cancer-bearing female presenting with a catheter-related bloodstream infection due to Gordonia otitidis. We detected G. otitidis from long-term blood cultures for approximately 6 days and prevented iatrogenic bacteremia by identifying the same organism from the culture of the PBSC sample and postponing the scheduled PBSCH. If febrile neutropenia occurs before PBSCH, we should collect multiple sets of blood cultures and culture them for a longer period.

Clinical utility of whole body diffusion-weighted imaging in an immunocompetent adult with atypical cat scratch disease.

BACKGROUND: Cat scratch disease (CSD) is an infectious disease caused by Bartonella henselae. CSD follows a typical course, characterized by regional lymphadenopathy. In atypical CSD, the lesions spread to systemic organs and can cause fever of unknown origin (FUO). A previous study showed the usefulness of whole-body magnetic resonance imaging (WB-MRI) with diffusion-weighted imaging (DWI) for limited areas in the diagnosis of FUO, but there are no studies on the clinical utility of whole-body DWI (WB-DWI). We herein report the case of an immunocompetent young man in whom contrast-enhanced CT-unidentifiable multiple liver abscess and osteomyelitis were successfully detected by WB-DWI. Follow-up with a liver biopsy helped confirm an atypical CSD diagnosis. CASE PRESENTATION: A 23-year-old previously healthy man was admitted for a 19-day history of high fever despite 3-day treatment by azithromycin. His physical examination was unremarkable and contrast-enhanced CT showed only a low attenuated area in the right lobe of the liver, indicating a cyst. WB-DWI revealed multiple nodular lesions of hypo-diffusion in the liver, spine, and pelvic region. The biopsy specimens of the liver abscess showed no evidence of tuberculosis/malignancy and the polymerase chain reaction (PCR) test of liver abscess aspirate showed positive findings for Bartonellahenselae, confirming the diagnosis of CSD. He completed minocycline monotherapy for a total of 60 days without any deterioration. CONCLUSIONS: WB-DWI can be useful for the diagnosis of atypical CSD with hepatic and bone involvement, which can cause FUO in young immunocompetent adults.

The first case report of pediatric acute appendicitis caused by "Candidatus Actinobaculum timonae".

A 14-year-old boy presented to the hospital with pain in the right lower abdomen. His condition was diagnosed as acute appendicitis. An emergency operation was performed, and histopathological examination revealed an actinomycete-related organism in the excised appendicitis specimen. On 16S rRNA gene sequence analysis, "Candidatus Actinobaculum timonae" was identified, which is the first known case in a pediatric patient.

[Comparative Study of Rapid Antigen Test Reagents for Group A Streptococcus spp.]

We compared rapid antigen detection kits widely used for the rapid diagnosis of group A streptococcal pharyngitis, evaluating their minimum detection sensitivity and operability in five levels. Five kits based on the immunochromatographic method were used: ImunoAce Strep A (Tauns), ImunoAce Strep A Neo (Tauns), Quick Navi-StrepA2 (Denka), Quick Vue Dipstick Strep A (SB Bioscience) and RapidTesta Strep A (SEKISUI MEDICAL). Thirteen strains were tested: 10 clinical isolates of Streptococcus pyogenes, 2 strains of Streptococcus dysgalactiae subsp. equisimilis (SDSE), and S. pyogenes ATCC 19615. All kits had the same or higher minimum detection sensitivity than previously reported. ImunoAce StrepA Neo had the highest detection sensitivity and the best overall evaluation among the group A streptococcal rapid antigen detection kits used in this study. The detection sensitivity of SDSE with group A polysaccharide antigen was comparable to that of S. pyogenes. Although culture tests are necessary to confirm the causative organism, SDSE may present with clinical symptoms similar to those of S. pyogenes, and detection with a rapid antigen detection kit may be of therapeutic value.

Neisseria macacae bacteremia: report of two cases with a literature review.

BACKGROUND: Neisseria macacae was discovered in the oral cavity of monkeys in 1983. In humans, it has been isolated from the upper respiratory tract of neutropenic patients. However, only two cases of N. macacae bacteremia have been reported in a 65-year-old man with infective endocarditis and a 5-month-old child with fever and petechiae. There are no reports of infections in cancer patients. Here, we present two cases of N. macacae bacteremia in cancer patients. CASE PRESENTATION: In the first case, a 42-year-old woman who underwent ovarian cancer surgery presented with duodenal invasion associated with multiple lymph node metastasis. N. macacae was isolated from her blood culture and identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). In the second case, a 69-year-old woman with a long-standing history of esophagogastric junction cancer presented with fever. She had stage IVB cancer with lung, bone, and multiple lymph node metastasis. The last chemotherapy was administered 5 weeks before N. macacae was detected using MALDI-TOF MS and nitrate test negative. In both cases, transthoracic echography showed no vegetation. Antibiotics were administered for 14 and 13 days in the first and second cases, respectively. In both cases, fever alleviated on day 4 of antibiotic administration. Both patients were discharged after their conditions improved. CONCLUSIONS: This, to our knowledge, is the first report of N. macacae bacteremia in cancer patients. Both patients, mucosal damage was observed in the upper gastrointestinal tract. Therefore, exclusion diagnosis suggested that bacteremia invasion was caused by mucosal rupture in both cases. Both cases responded well to treatment with ß-lactam antibiotics and improved after 2 weeks. Modifying the treatment based on the source of the infection may shorten the treatment period. Therefore, further research on N. macacae bacteremia is necessary. Immunocompromised patients such as those with cancer are susceptible to mucosal damage by unusual bacterial species such as N. macacae despite not having contact with monkeys.

Isolated mediastinal lymphadenitis caused by Mycobacterium malmoense in an immunocompromised child.

Mycobacterium malmoense is a nontuberculous mycobacteria (NTM), that is uncommon in areas other than Northern Europe. We describe the case of mediastinal lymphadenitis caused by M. malmoense in a 4-year-old boy who has a past medical history of disseminated Bacille de Calmette et Guérin (BCG) infection. He presented with persistent high fever and computed tomography revealed mediastinal lymphadenopathy. We identified M. malmoense by hsp65 gene analysis from a lymph node biopsy sample. We treated him with rifampicin, ethambutol and clarithromycin with reference to the guidelines of the British Thoracic Society. M. malmoense can cause severe infections including mediastinal lymphadenitis in children with susceptibility to acid-fast bacteria (AFB).

Evaluation of presumptive identification of Enterobacterales using CHROMagar Orientation medium and rapid biochemical tests.

BACKGROUND: The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is gradually spreading among large-scale laboratories; however, this method is impractical for small-scale laboratories. In laboratories without access to these rapid identification methods, problems related to them remain unsolved. In this study, we aimed to develop a rapid and inexpensive method to presumptively identify Enterobacterales using CHROMagar Orientation medium. METHODS: The algorithm for presumptive identification of Enterobacteriaceae using CHROMagar Orientation medium was based on our previous studies. Modified property tests for indole, lysine decarboxylase, ornithine decarboxylase, and hydrogen sulfide were performed to evaluate the differentiation of the bacterial species. RESULTS: Using the type strains and clinical isolates, it was possible to conduct the property tests at a low cost, within 4 hours. The spot indole test was performed without any nonspecific reactions for the bacteria forming colored colonies. The presumptive identification of bacteria was thereby possible within 24 hours after specimen submission. CONCLUSION: All these results suggest that the rapid presumptive identification of Enterobacterales is possible with this new identification method using CHROMagar Orientation medium. This is therefore a prompt and economical method that can be used in routine laboratory work.

Splenic infarction complicated with immune reconstitution inflammatory syndrome due to disseminated Mycobacterium genavense infection in a patient infected with human immunodeficiency virus.

Mycobacterium genavense (M. genavense) is one of the most fastidious, difficult to culture Mycobacterium species. Patients infected with human immunodeficiency virus (HIV) may develop immune reconstitution inflammatory syndrome (IRIS) due to disseminated M. genavense infection as well as disseminated M. avium and intracellulare complex infection. Consensus regarding treatment of IRIS due to disseminated mycobacterium infection has not yet been obtained, although systemic steroid therapy has been recommended in recent guidelines. Here we report the case of a 48-year-old Japanese man diagnosed with HIV and disseminated M. genavense infection. His initial CD4-positive T cell count was 3/µL, and his HIV1-RNA viral load was 13,000 copies/mL. He developed IRIS due to disseminated M. genavense infection after two weeks of receiving antiretroviral agents. The patient's serum alkaline phosphatase level, as a barometer of disseminated M. genavense infection in this case, was difficult to control with several anti-mycobacterial agents, although his fever was improved by non-steroidal anti-inflammatory drugs. About five weeks after the onset of IRIS, the patient developed acute left upper quadrant pain and was diagnosed with splenic infarction by contrast-enhanced computed tomography. After the splenic infarction, the patient's serum alkaline phosphatase level decreased without systemic steroid therapy or anticoagulant agents, and his left upper quadrant pain improved naturally within a few days. This case suggests that IRIS due to disseminated M. genavense infection can complicate splenic infarction in patients with HIV, and splenic infarction could improve the IRIS due to disseminated M. genavense infection.

Slightly acidic electrolyzed water disrupts biofilms and effectively disinfects Pseudomonas aeruginosa.

INTRODUCTION: Biofilm formation is an important issue in the healthcare industry, but conventional disinfectants are not effective for biofilms formed in the hospital environment and on medical instruments. In this study, aim at determine the effectiveness of slightly acidic electrolyzed water (SAEW) on biofilm removal and the disinfection of biofilm-forming Pseudomonas aeruginosa. METHODS: Mucoid and non-mucoid strains were used for biofilm formation. Biofilms were incubated with SAEW and the reduction in biofilm volume was determined based on the optical density. Furthermore, to investigate the mechanism underlying the effects of SAEW, a biofilm was produced with alginate and structural changes in response to incubation with SAEW were observed by fluorescence microscopy. The minimum bactericidal chlorine concentration of SAEW for P. aeruginosa cells was evaluated. RESULTS: The amounts of alginate and biofilm decreased by 99.9% and 56.8% immersed by 30 ppm of SAEW at 25 °C for 10 min. The effectiveness of SAEW increased as the temperature increased, and the biofilm volume was reduced by 85.4% at 45 °C. Furthermore, 30 ppm SAEW completely disinfected P. aeruginosa in the biofilm, even for immersion at 15 °C for 5 min. CONCLUSION: Our results suggest that SAEW, a low-cost and safe chlorine disinfectant, is a useful disinfectant for biofilm-forming bacteria.

Identification and antifungal sensitivity of two new species of Diaporthe isolated.

Diaporhte species are plant pathogens rarely involved in human diseases, especially eye diseases. We report our findings in two undescribed Diaporhte species. Both were identified by their morphological characteristics and by DNA sequence analyses. In Case 1, an 81-year-old male farmer who had pterygium surgery 7 years earlier developed keratitis and the causal fungus was identified as a new species of Diaporthe, D. oculi. This species can be distinguished from the closely related D. limonicola on Citrus limon (Rutaceae) by the ITS, tef1, and TUB (515/520 = 99.0% in ITS, 315/324 = 97.2% in tef1, and 601/614 = 97.9% in TUB). The isolate from Case 2, a 68-year-old man with a rose thorn injury, was also identified as a new Diaporthe species, D. pseudooculi. Phylogenetically, D. pseudooculi is different from the closely related D. podocarpi-macrophylli by the ITS, tef1, and TUB (525/531 = 98.9% in ITS, 314/333 = 94.3% in tef1, and 436/442 = 98.6% in TUB). We report on the identification, drug sensitivity, and treatment outcomes for these two new species of Diaporthe, D. oculi and D. pseudooculi.

First case of a bloodstream infection caused by the genus Brachybacterium.

An 83-year-old previously self-sufficient man was referred to our hospital for a fever, severe tenderness over the lumbar spine, and elevated C-reactive protein levels. Computed tomography revealed fluid collection in the intervertebral space of L3/4. Gram-positive, short rod-shaped bacteria were isolated from two sets of blood cultures. A 16S rRNA sequence analysis of an isolate showed a similarity of 98.1% to the nearest type strain Brachybacterium squillarum JCM 16464T. Biochemical characteristics of the presently isolated strain differed from those of the most closely related species of the genus Brachybacterium. The patient was successfully discharged on day 73 of admission with antimicrobial therapies and showed no recurrence during outpatient visits. Brachybacterium spp. have mainly been isolated from the environment, and human Brachybacterium infections have rarely been documented to date. To our knowledge, this is the first clinical isolation of Brachybacterium sp. as a causative pathogen of bloodstream infection.

Invasive meningococcal disease due to ciprofloxacin-resistant Neisseria meningitidis sequence type 4821: The first case in Japan.

We present a 4-year-old girl who developed invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup C sequence type (ST)-4821. She was hospitalized due to fever, vomiting, rash and altered consciousness. Serogroup C N. meningitidis was isolated from blood culture taken on admission and was confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, a biochemical test, and molecular microbiological analysis. The patient was successfully treated with 50 mg/kg ceftriaxone every 12 hours for 7 days without any complications. The isolate was susceptible to a wide variety of ß-lactams and rifampin but was resistant to ciprofloxacin. The isolate harbored gyrA T91I and parC S87I mutations at the quinolone-resistance-determining regions. Multi-locus sequence typing revealed the isolates as ST-4821, which was identical to an endemic clone frequently detected in China. However, neither the patient nor her family members had traveled abroad. To our knowledge, this report is the first to describe an IMD patient caused by ciprofloxacin-resistant N. meningitidis ST-4821 in Japan, and is the first community-acquired IMD case due to this strain outside of China. The high proportion of ciprofloxacin resistance and hypervirulent features of this ST-4821 strain raise special public health concerns. We still consider ciprofloxacin is still appropriate drug for post-exposure chemoprophylaxis in Japan. However, nationwide surveillance for susceptibility of IMD isolates is necessary to establish the regional antibiogram, and thereby to avoid chemoprophylaxis failure.

Disseminated Mycobacterium genavense Infection in Patient with Adult-Onset Immunodeficiency.

We report a case of disseminated Mycobacterium genavense infection resulting from neutralizing anti-interferon-γ autoantibodies in the patient. We identified M. genavense targeting the hsp65 gene in an aspiration specimen of the lymph node. Adult-onset immunodeficiency caused by neutralizing anti-interferon-γ autoantibodies, in addition to HIV infection, can lead to disseminated nontuberculous mycobacterial infection.

The first case report of emphysematous pyelonephritis and bacteremia due to Oligella urethralis.

Oligella urethralis (O. urethralis) is an organism that rarely causes infections in humans. We report the case of a 90-year-old bedridden woman with progressive dementia who was placed in a long-term-care facility. She was admitted to our hospital due to fever and unconsciousness with pyuria. The abdominal computed tomography showed left pneumatosis and urinary stone. Fluoroquinolones-resistant O. urethralis, which was identified by the Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) and the 16S rRNA gene sequencing, was isolated form the blood and urine cultures at admission. To the best of our knowledge, this is the first case of emphysematous pyelonephritis caused by O. urethralis.

Phanerochaete sordida as a cause of pulmonary nodule in an immunocompromised patient: a case report.

BACKGROUND: Phanerochaete sordida is a species of wood rotting fungus, which can degrade lignin, cellulose and hemicellulose contained in wood and other hard-to-biodegrade organic substances. However, to date, there have been no other reports demonstrating that P. sordida can infect humans. CASE PRESENTATION: A 66-year-old Japanese man presented for a mass increasing in size on his left thigh. He had been suffering from rheumatoid arthritis for 18 years and chronic obstructive pulmonary disease for 20 years, for which he was being treated with 5 mg/day prednisolone and 8 mg/week methotrexate. The mass resection was performed two months later, and was diagnosed as malignant fibrous histiocytosis. However, a computed tomography examination for tumor recurrence after surgery showed a newly emergent pulmonary nodule. We therefore decided to resect the nodule by thoracoscopic procedure. Histopathological examination of the excised specimen showed that the lesion was a granuloma, with necrotic tissue and clumping of Aspergillus-like hyphae. Therefore, the nodule was diagnosed as a fungal infection and tissue specimens were cultured microbiologically. However, fungal growth was not observed. We consequently performed genetic analysis using a broad-range polymerase chain reaction. The 28S rRNA sequence demonstrated 100% homology with P. sordida using the NCBI BLAST program against the GenBank DNA databases. CONCLUSIONS: Using broad-range polymerase chain reaction, we identified P. sordida as the causative agent of a pulmonary nodule. These findings indicate that P. sordida may be an additional opportunistic causative organism of pulmonary infection in immunocompromised patients.

Roussoella solani causing keratomycosis, with an observed both sexual and asexual morphs.

We describe an 82-year-old male farmer who had diabetes mellitus with no history of ocular trauma by soil or plants and who developed a corneal infection due to a fungus. The organism was identified as Roussoella solani based on both the morphological characteristics and phylogenetic analysis using LSU and ITS nrDNA sequences. The sexual stage of R. solani is described and illustrated for the first time. The patient was treated successfully with a combination of topical and systemic voriconazole and micafungin. This case is the first report of keratomycosis caused by R. solani.