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.

Recurrent Bacillus subtilis Var. Natto Bacteremia and Review of the Literature on Bacillus subtilis: The First Case Report

BACKGROUND Fermented foods, such as yogurt, are often considered healthy; however, there have been numerous reported cases of bacteremia associated with their consumption. In this report, we present a case of Bacillus subtilis var. natto (B. subtilis var. natto) bacteremia related to the consumption of natto, a traditional Japanese food made from fermented soybeans. We also conducted a literature review on B. subtilis bacteremia. CASE REPORT We report the case of a 41-year-old woman who presented with fever, had a medical history of congenital liver fibrosis, and experienced recurrent B. subtilis var. natto bacteremia along with acute cholangitis. Although she discontinued eating natto, she developed pyogenic thrombophlebitis due to B. subtilis var. natto. We successfully treated her with meropenem and an anti-coagulant. To investigate the management and prognosis of B. subtilis var. natto bacteremia, we conducted a literature review of B. subtilis intra-abdominal infection. We identified 17 papers describing 30 cases of B. subtilis intra-abdominal infection, 4 cases of which were caused by B. subtilis var. natto; the median age of the patients was 71 years (range, 15-96 years), 14 patients (47%) were female, and 3 patients (10%) died. From our findings, our case was the only one of recurrent B. subtilis var. natto infection. Even after patients discontinue eating natto, they should be carefully monitored. CONCLUSIONS Due to advancements in PCR identification techniques, case reports of infections caused by B. subtilis var. natto are increasing.

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.

A rare case of Bacillus subtilis variant natto-induced persistent bacteremia with liver and splenic abscesses in an immunocompetent patient

Bacillus subtilis var. natto, a low-pathogenic bacterium used in the traditional Japanese food "natto" (fermented soybeans), has rarely been reported as a pathogen of infectious diseases in humans. Herein, we report the first case of persistent bacteremia caused by B. subtilis var. natto in an immunocompetent patient without any gastrointestinal involvement. A 53-year-old Japanese woman who had been consuming natto every day was admitted to our hospital with complaints of fever and chills. B. subtilis was isolated from blood cultures collected during the initial visit. Abdominal contrast-enhanced computed tomography (CT) showed multiple low-absorption areas in the liver and spleen. Treatment commenced with vancomycin; however, Bacillus sp. was re-detected in the blood culture on day 4 after treatment initiation. The blood culture on day 8 was negative. Subsequently, the treatment was switched to ampicillin-sulbactam and oral amoxicillin-clavulanic acid, and the patient recovered after 28 days of treatment from the time the blood cultures became negative. Contrast-enhanced CT of the abdomen at the end of treatment showed that the multiple low-absorption areas in the liver and spleen had disappeared. Later, the variant of the bacteria was identified as B. subtilis var. natto by DNA analysis. B. subtilis var. subtilis and B. subtilis var. natto cannot be distinguished using matrix-assisted laser desorption/ionization-time of flight mass spectrometry or 16S rRNA analysis. Biotin auxotrophy of B. subtilis var. natto is used to distinguish between the two variants.

Enterococcus faecium 129 BIO 3B is classified as Enterococcus lactis 129 BIO 3B

Enterococcus faecium 129 BIO 3B is a lactic acid bacterium that has been safely used as a probiotic product for over 100 years. Recently, concerns about its safety have arisen because some species of E. faecium belong to the vancomycin-resistant enterococci. The groups of E. faecium with less pathogenic potential have been split into a separate species (Enterococcus lactis). In this study, I investigated the phylogenetic classification and safety of E. faecium 129 BIO 3B as well as E. faecium 129 BIO 3B-R, which is naturally resistant to ampicillin. Mass spectrometry and basic local alignment search tool analysis using specific gene regions failed to differentiate 3B and 3B-R into E. faecium or E. lactis. However, multilocus sequence typing successfully identified 3B and 3B-R as the same sequence types as E. lactis. Overall genome relatedness indices showed that 3B and 3B-R have high degrees of homology with E. lactis. Gene amplification was confirmed for 3B and 3B-R with E. lactis species-specific primers. The minimum inhibitory concentration of ampicillin was confirmed to be 2 µg/mL for 3B, which is within the safety standard for E. faecium set by the European Food Safety Authority. Based on the above results, E. faecium 129 BIO 3B and E. faecium 129 BIO 3B-R were classified as E. lactis. The absence of pathogenic genes except for fms21 in this study demonstrates that these bacteria are safe for use as probiotics.

[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.

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.

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.

Thoracic Empyema Caused by Campylobacter rectus

Campylobacter rectus is a campylobacterium considered to be a primary periodontal pathogen. Thus, C. rectus has rarely been isolated from extraoral specimens, especially in the thoracic region. We herein report a case of thoracic empyema in which Campylobacter infection was suspected after Gram staining of the pleural effusion, and C. rectus was isolated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Fusobacterium nucleatum was also detected. Molecular identification was performed using polymerase chain reaction amplification and a sequencing analysis of the 16S rRNA gene. Estimation of the causative bacteria using Gram staining led to the proper culture and identification of the causative bacteria.

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.

Acid-fast bacilli smear test of a blood culture sample for the diagnosis of disseminated Mycobacterium genavense infection: A case report

Mycobacterium genavense, a nontuberculous Mycobacterium, is found in immunosuppressed patients, particularly in those with HIV. Mycobacterium genavense incubation under standard culture conditions is difficult, and its identification is challenging using routine culture methods. Herein, we report the case of a 40-year-old Japanese man with HIV presenting with disseminated M. genavense infection. An analysis using an automated blood culture system did not show positive signals during 6 weeks of incubation. However, an acid-fast bacilli smear of his blood sample was positive for the bacterium. Mycobacterium genavense was identified using sequencing analysis, targeting the heat shock protein 65 gene. The patient recovered from the infection, following antibiotic therapy for 18 months. Under suspicion of disseminated M. genavense infection and the absence of bacterial growth in blood culture samples, an acid-fast bacilli smear test of the sample may be useful for timely diagnosis.

Prosthetic joint infection after total hip arthroplasty caused by Sneathia sanguinegens: A case report (CARE-complaint)

INTRODUCTION

Sneathia sanguinegens(S sanguinegens) is a gram-negative rod-shaped bacterium mostly reported to cause a perinatal infection, and there are no reports of S sanguinegens in prosthetic joint infection (PJI). The purpose of this report is to describe a very rare case of PJI after total hip arthroplasty (THA) caused by S sanguinegens.

PATIENT CONCERNS

A 79-year-old woman presented with right coxalgia, inability to walk, and a fever of 39°C. She had undergone THA 28 years earlier for osteoarthritis of the hip.

DIAGNOSES

The diagnosis was acute late-onset PJI, because blood tests revealed marked inflammatory reaction and computed tomography showed an abscess at the right hip joint; synovial fluid analysis resulted in detection of a gram-negative bacillus.

INTERVENTION

Surgical debridement with retention of the implant and antibiotic therapy was performed.

OUTCOMES

One month after surgery, polymerase chain reaction (PCR) assay showed that the pathogen was 99.9% likely to be S sanguinegens. There has been no recurrence of infection or loosening of the implant in the 2 years since her surgery.

LESSONS

PCR should facilitate detection of previously unknown pathogens and potentially novel bacterial species.

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.

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 β-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).

Brachybacterium paraconglomeratum Endophthalmitis Postcataract Operation

PURPOSE

To present our findings in a case of delayed-onset postoperative endophthalmitis caused by Brachybacterium paraconglomeratum, a rare organism. Observations. A 57-year-old man presented with epiphora and photophobia 17 weeks after a routine cataract extraction with phacoemulsification and intraocular lens implantation. Because endophthalmitis was suspected to be caused by a low-grade pathogen or fungus, an anterior chamber tap was performed. However, both multiplex PCR and culturing were negative. The patient was treated with topical cefmenoxime, oral minocycline, and subconjunctival injection of vancomycin and ceftazidime, but the intraocular inflammation increased. Then, the anterior chamber was tapped again, and the second PCR amplification and direct sequencing which targeted Actinomycetes detected Brachybacterium paraconglomeratum, a rare organism.

CONCLUSION

This is the first reported case of an ocular disorder caused by B. paraconglomeratum. We recommend that B. paraconglomeratum be considered in cases of delayed-onset postcataract endophthalmitis.B. paraconglomeratum. We recommend that B. paraconglomeratum be considered in cases of delayed-onset postcataract endophthalmitis.

Clonal spread of serotype 12F ST4846 Streptococcus pneumoniae

Introduction. In 2016-2017, there was an increase in the number of paediatric invasive pneumococcal disease (IPD) cases caused by Streptococcus pneumoniae serotype 12F in Chiba Prefecture, Japan. Serotype 12F is one of the major causative serotypes of IPD following the introduction of pneumococcal conjugate vaccine 13 (PCV13), and outbreaks of IPD caused by serotype 12F have recently been reported in several countries.Aim. Our goal here was to clarify the relationship among local outbreak strains and the outbreak strains in other countries, and for this we analysed clinical isolates of S. pneumoniae serotype 12F using several genetic identification methods.Methodology. All reported IPD cases caused by serotype 12F were reviewed and bacterial strains were collected and analysed. We also analysed S. pneumoniae serotype 12F strains isolated from other time periods, geographical areas, cases of adult IPD and respiratory specimens as control strains. Multi-locus sequence typing, PFGE and multi-locus variable number tandem repeat analysis (MLVA) were conducted on all isolates.Results. All 26 S. pneumoniae serotype 12F isolates, including control strains, belonged to a single sequence type (ST4846) that was the specific ST in Japan. All tested strains demonstrated five MLVA patterns and two PFGE patterns.Conclusion. We determined that the 2016-2017 outbreak of IPD in Chiba Prefecture was caused by clonally related isolates of serotype 12F. The continuous monitoring of IPD caused by serotype 12F is important for evaluating the impact of re-emerging pneumococcal serotypes following the PCV13 introduction era, and MLVA could be a useful tool for identification of outbreak strains.

Culture-negative group B streptococcal pericarditis: A case report and literature review of the diagnostic use of polymerase chain reaction

Although conventional microbiology cultures may be negative, polymerase chain reaction (PCR) can effectively identify both typical and atypical microorganisms. With careful interpretation, PCR could become the gold-standard diagnostic test for culture-negative bacterial pericarditis.

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.

Characteristics of Resistance Mechanisms and Molecular Epidemiology of Fluoroquinolone-Nonsusceptible Salmonella enterica Serovar Typhi and Paratyphi A Isolates from a Tertiary Hospital in Dhaka, Bangladesh

The aim of this study was to characterize the fluoroquinolone (FQ) resistance mechanism of Salmonella enterica serovar Typhi and Paratyphi A in Bangladesh. Salmonella Typhi isolates were classified into sequence type (ST) 1, ST2, and ST2209 and Salmonella Paratyphi A isolates were classified into ST85 and ST129. The most common STs of the FQ-nonsusceptible strain were ST1 (44.4%) and ST129 (66.6%). Thirty-nine percent of Salmonella Typhi isolates were multidrug resistant, and these were all ST1, which is the type prevalent in the Indian subcontinent. Although plasmid-mediated quinolone resistance genes were not detected in any of the tested strains, single and double mutations were identified in the quinolone resistance-determining region (QRDR). The most common QRDR mutation was GyrA_Ser83Phe (66.7% for Salmonella Typhi and 100% for Salmonella Paratyphi A). Treatment with an efflux pump inhibitor resulted in susceptibility of the strains to levofloxacin. All isolates demonstrated 100% susceptibility to ceftriaxone, azithromycin, and carbapenem. Our results suggest that mutations in gyrase A and enhancement of efflux pump activity are responsible for the resistance to FQs; in particular, the AcrAB-TolC efflux pump may be an important resistance factor for levofloxacin. To control the spread of FQ-nonsusceptible Salmonella Typhi, intensive surveillance in endemic areas, including Bangladesh, and effective infection control are necessary.

Gemella haemolysans bacteremia in a patient with secondary peritonitis due to a duodenal ulcer perforation: A case report

We describe a case of Gemella haemolysans septic shock in a 75-year old Japanese male with a duodenal perforation and secondary peritonitis. Blood cultures on admission were positive for Gram-positive and Gram-variable cocci, and G. haemolysans was identified using whole cell matrix-assisted laser desorpition/ionization mass spectrometry (MALDI-TOF MS), with a score value of 2.12. The 16S rRNA sequencing was difficult to use as a diagnostic test because there was more than 99% sequence homology with related bacterial strains. Based on both the biochemical profiles and whole groEL sequence, we concluded that the strain in our patient was G. haemolysans. The patient was successfully treated with a 16-day course of antimicrobials. His clinical condition improved, and no evidence of a relapse of the infection was noted. Although MALDI-TOF MS and 16S rRNA sequencing are useful for identification of the species, the basic biochemical profile is also important to identify a rare species.

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.

Trauma Wound Related Infection Caused by Enterobacter cancerogenus and Aeromonas hydrophilia

We herein describe a case of trauma-related wound infection with a subcutaneous abscess caused by both Enterobacter cancerogenus and Aeromonas hydrophila. An 89-year-old Japanese man was admitted to our hospital because of an injury that he had suffered in a car accident. The right dorsal region of the foot around the wound was reddish and swelling. The pus culture on his right foot grew E. cancerogenus and A. hydrophila. The patient was successfully treated with a 10-day course of meropenem and a 25-day course of levofloxacin. E. cancerogenus can therefore be a causative pathogen in skin and soft tissue infections among trauma patients.

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 β-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.

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.

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.

[Mycotic Aneurysm by Saccharomyces cerevisiae-accompanying Ascending Aortic Graft Infection: A Case Report]

We treated an extremely rare case of a mycotic aneurysm with infection of an artificial blood vessel by Saccharomyces cerevisiae, which was the first case in Japan. The patient was an 84-year-old woman. Five months before hospitalization, replacement of the ascending aorta was performed for a dissecting aneurysm of the ascending aorta. On regular follow-up examination, she had no symptoms, but accumulation of a liquid was detected around the artificial blood vessel on computed tomography (CT) imaging. She was immediately hospitalized. An emergency operation was performed because of the infected aneurysm, which accompanied infection of the artificial blood vessel. We could not detect any microorganisms in the blood or tissue culture, but we made a diagnosis of S. cerevisiae infection after performing broad-range polymerase chain reaction (PCR), followed by deoxyribonucleic acid (DNA) sequencing analysis. When an infected aneurysm is suspected after imaging analysis, such as CT, in a patient without fever or chest pain and with poor inflammatory reactions, an infected aneurysm caused by a fungus should be considered, even though blood or tissue culture results are negative. It is important to perform histopathological examination using Grocott silver stain and genetic testing (broad-range PCR and DNA sequencing analysis) of the tissue to identify the fungal infection. In the elderly, the number of cases of infection with S. cerevisiae may increase, and these cases may require more attention in the near future.

A Case Study of Rat Bite Fever Caused by Streptobacillus moniliformis

We report a case of rat bite fever, diagnosed based on positive cultures of Streptobacillus moniliformis from blood and synovial fluid. The patient was a 45-year-old man who presented with history of a rat bite and alcoholic liver cirrhosis. He had been bitten on his third finger by a rat, which was caught in a mousetrap installed in his house. Over the course of approximately 2 weeks after the bite, the patient developed fever, rash, and arthralgia. The patient was admitted to our hospital and treated with a combination of ampicillin-sulbactam, vancomycin (VAN), and minocycline (MIN) antibiotics. Initial culture findings from the Anaerobic/F resin blood culture were positive for gram-negative bacillus after overnight incubation. Thus, S. moniliformis infection was suspected, and administration of VAN and MIN was ceased. On hospital day 8, the treatment was switched to oral amoxicillin-clavulanic acid, and the patient was discharged from the hospital. Subsequently, the pathogen was also detected in synovial fluid and identified as S. moniliformis using 16S rRNA sequencing analysis.

Evaluation and validity of a polymerase chain reaction-based open reading frame typing method to dissect the molecular epidemiology for Acinetobacter baumannii in an epidemiologic study of a hospital outbreak

Acinetobacter baumannii is regarded as one of the most important pathogens in hospital outbreaks. To obtain an efficient and simple epidemiologic method of surveillance during outbreaks, we assessed the applicability of the polymerase chain reaction-based open reading frames typing (POT) method and compared it with pulsed-field gel electrophoresis. The POT method was found to have sufficient discriminatory power to identify the strains and would be widely applicable to epidemiologic surveillance during hospital outbreaks.

First case report of infection due to Cupriavidus gilardii in a patient without immunodeficiency: a case report

BACKGROUND

Cupriavidus gilardii is an aerobic, Gram-negative, glucose-nonfermenting rod that was first identified in 1999. Because of the difficulty in accurate species identification of C. gilardii, there are few case reports of infection caused by this organism. In previous reports, C. gilardii has been characterized as an organism with low pathogenicity that causes opportunistic infections.

CASE PRESENTATION

We encountered a case of pacemaker-associated bloodstream infection caused by C. gilardii in a 90-year old woman without obvious immunodeficiency. We identified the isolates as C. gilardii by sequencing of the 16S rRNA gene. The patient was treated with removal of the lead and administration of antimicrobial agents. Because of the acquisition of antibiotic resistance during antibiotic treatment, the antimicrobial agent was changed during the course of treatment.

CONCLUSIONS

To our knowledge, this is the first report of an infection caused by this organism in a patient without obvious immunodeficiency. Although the true pathogenicity of C. gilardii is unclear, the possibility that it exerts pathogenicity not only in persons with immunodeficiency but also in immunocompetent persons is suggested.

The First Case Report of Cerebral Cyst Infection Due to Helicobacter cinaedi

We report the first case of cerebral cyst infection by Helicobacter cinaedi, a fastidious spiral-shaped gram-negative rod bacterium. A 70-year-old man visited Tokyo Medical University Hospital with persisting fever since 2 weeks. He underwent surgery and radiotherapy for parapharyngeal space squamous cell carcinoma 10 years ago. The radiotherapy resulted in a cerebral cyst as a side effect, and an Ommaya reservoir was inserted into the cyst. Blood culture and analysis of the brain cyst fluid revealed the presence of spiral-shaped gram-negative rod bacteria, which were identified as H. cinaedi by polymerase chain reaction. Initially, we administered clarithromycin (400 mg per day). After H. cinaedi infection was confirmed, the treatment was changed to meropenem (MEPM 6 g per day). The patient was treated for 43 days in the hospital with intravenous meropenem, and his clinical course was satisfactory. On the 44th day, he was discharged and prescribed oral minocycline (MINO 200 mg per day). After discharge, the patient's H. cinaedi infection did not recur. Our case illustrated the wide clinical spectrum of H. cinaedi as well as the effectiveness of antibiotic therapy comprising MERM and MINO for treating central nervous system infection by this organism.

Helicobacter fennelliae Bacteremia: Three Case Reports and Literature Review

Helicobacter fennelliae is a gram-negative, spiral bacillus that appears as thin-spread colonies on sheep blood agar and is similar to Helicobacter cinaedi. H fennelliae is diagnosed by genetic testing, which is not readily available in all laboratories. Therefore, H fennelliae bacteremia has only been reported sporadically, and little is known about its clinical characteristics.We describe 3 cases of H fennelliae bacteremia with gastrointestinal symptoms, including nausea, vomiting, and diarrhea. Isolates could be differentiated from H cinaedi by biochemical reaction testing, including nitrate reduction and alkaline phosphatase hydrolysis.We retrospectively reviewed 24 cases of H fennelliae bacteremia reported in the literature. Most of the patients had immunosuppressive backgrounds, including solid tumors, hematological malignancies, and autoimmune diseases. Although gastrointestinal symptoms were common, cellulitis was not often observed in patients with H fennelliae bacteremia.Clinicians should bear in mind that H fennelliae may be a differential diagnosis in patients with gastrointestinal manifestations and gram-negative, spiral bacilli. In addition, biochemical reactions, such as nitrate reduction and alkaline phosphatase hydrolysis, are useful in differentiating H fennelliae from H cinaedi.

Case of late-onset bleb associated endophthalmitis caused by Rothia mucilaginosa

Rothia mucilaginosa is a gram-positive coagulase-negative coccus of the family Micrococcaceae. Although R. mucilaginosa forms part of the oropharyngeal microflora, it has only recently been isolated in ocular infections. We report a case of a 41-year-old man who developed late-onset bleb-related endophthalmitis (BRE). He had undergone glaucoma surgery 21 years earlier and had a thin-walled cystic bleb prior to the development of endophthalmitis in his right eye. He immediately received intravitreal injections of ceftazidime and vancomycin, topical levofloxacin and cefmenoxime, and intravenous cefozopran. Culture of the aqueous humor specimen identified R. mucilaginosa by 16S rRNA sequence analysis. To our knowledge, this is the first report of late-onset BRE caused by R. mucilaginosa. Our case indicates that R. mucilaginosa can be a cause of late-onset BRE, and that molecular analysis is an accurate method to identify R. mucilaginosa.

Blood stream infections caused by Acinetobacter baumannii group in Japan - Epidemiological and clinical investigation

Acinetobacter calcoaceticus-Acinetobacter baumannii complex, especially A. baumannii, Acinetobacter pittii and Acinetobacter nosocomialis, constitutes an important group of nosocomial pathogens; however, epidemiological or clinical characteristics and prognosis is limited in Japan. From 2009 to 2013, 47 blood stream infection cases resulting from A. baumannii group were reviewed at the National Defense Medical College, an 800-bed tertiary hospital. To determine the genospecies, further comparative nucleotide sequence analyses of the RNA polymerase b-subunit (rpoB) gene were performed. Sequence analysis of rpoB gene showed that 25 (49.0%), 17 (33.3%) and 5 (9.8%) cases were caused by A. baumannii, A. pittii and A. nosocomialis, respectively. The 30-day and in-hospital mortality rates of A. baumannii were 8.5% and 25.5%, respectively, and there were no significant differences between Acinetobacter species. Clinical characteristics were statistically insignificant. Multidrug-resistant Acinetobacter species were detected in 3 cases (5.9%) with same pulsed-field gel electrophoresis (PFGE) pattern and A. baumannii was less susceptible to amikacin and levofloxacin. In this study, the mortality and clinical characteristics were similar among A. baumannii group isolate cases despite some showing drug resistance. However, identification of Acinetobacter species helps to initiate appropriate antibiotic therapy in earlier treatment phase, because A. baumannii shows some drug resistance.

Catheter-Related Bloodstream Infection Due to Lodderomyces elongisporus

Lodderomyces elongisporus infrequently causes bloodstream infections and has been isolated from Asia and Mexico. We encountered a catheter-related bloodstream infection, which involved some risk factors, due to L. elongisporus masquerading as Candida parapsilosis. A 39-year-old man who received a total arch and thoracoabdominal aortic replacement was admitted with a diagnosis of aorto-esophageal fistula. After thoracic drainage for the aorto-esophageal fistula, a catheter-related bloodstream infection was diagnosed. Micafungin (100 mg/day) was successfully administered to treat the catheter-related bloodstream infection for 42 days in total. The bloodstream and catheter tip yeast was grown on Candida agar medium and produced dark green colonies indicating Candida albicans. We performed sequencing analysis using a GenBank BLAST search. The sequence of the internal transcribed spacer region was 99.9% identical with that of the type strain L. elongisporus. This yeast organism has frequently been technically mistaken for non-albicans Candida spp. Furthermore, the prognosis and risk factors of L. elongisporus infection remain unclear owing to the scarcity of reported cases. Catheter-related bloodstream infection caused by this organism has not been described to date.

Cellulitis and Bacteremia due to Corynebacterium striatum Identified by Matrix-assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

Corynebacterium striatum has been described as a pathogen in immunocompromised patients; however, correctly identifying Corynebacterium spp. is often difficult, and cases of cellulitis caused by C. striatum are only rarely reported. We herein describe a case of cellulitis and bacteremia due to C. striatum identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Antimicrobial susceptibility testing was performed using the Strepto-Haemo Supplement method, and vancomycin was replaced by a narrow-spectrum oral amoxicillin.

[Molecular Approaches for the Diagnosis of Central Nervous System Infections]

In recent years, molecular microbiology techniques have proven to be a useful supplement to conventional assays not only in identification of strains from culture, but also in direct detection of pathogens from clinical specimens. This review explores the application of molecular diagnostic techniques for infectious diseases in certain clinical contexts. It aims to assess how these molecular techniques can be integrated to enhance diagnostic capabilities for infectious diseases of the central nervous system. Finally, it emphasizes the need for close collaboration between physicians and clinical microbiologists when considering molecular diagnostics from unusual specimens/cases, because assays must be customized according to the clinical settings.

Severe infective endocarditis in a healthy adult due to Streptococcus agalactiae

A case of severe endocarditis, with complications of multiple infarction, meningitis, and ruptured mitral chordae tendineae, caused by Streptococcus agalactiae in a healthy man, is reported. Emergency cardiovascular surgery was performed on the day of admission. Infective endocarditis caused by S. agalactiae is very rare, particularly in a healthy adult. In addition, microbiological analysis revealed that S. agalactiae of sequence type (ST) 19, which belongs to serotype III, was present in the patient's vegetation, mitral valve, and blood culture. It was therefore concluded that the endocarditis was caused by ST19, which has been reported as a non-invasive type of S. agalactiae. This was an extremely rare case in which S. agalactiae of ST19 caused very severe endocarditis in an adult patient with no underlying disease.

Tsukamurella inchonensis infection in a child with Hodgkin's lymphoma

Tsukamurella spp. infection is a rare but important cause of bacteremia in immunocompromised patients. The organism is an aerobic, Gram-positive, weakly acid-fast bacillus that is difficult to differentiate from other aerobic Actinomycetales by standard laboratory methods. Here, we report on the case of a 14-year-old patient with Hodgkin's lymphoma who, after intensive chemotherapy, developed Tsukamurella inchonensis bacteremia, which was identified on the peripherally inserted central venous catheter (PICC) using 16S rRNA sequencing analysis. The bacteremia was successfully controlled with antimicrobial therapy and subsequent removal of the PICC. This is the first report of bacteremia by Tsukamurella inchonensis in immunocompromised children. Careful observation and prompt analysis of opportunistic infection, including Tsukamurella spp., is very important in immunocompromised children.

[A first case report of empyema caused by Tetratrichomonas species in Japan]

Trichomonad is a type of flagellate that parasitizes the human oral cavity, intestine, or vagina. However, respiratory infection is rare. We report a patient with pyothorax related to Tetratrichomonas species, which is the first reported case in Japan. The patient was a 66-year-old female. She consulted the Emergency Outpatient Unit of our hospital with fever, dyspnea, and the retention of pleural effusion. The appearance of the pleural effusion collected by thoracic drainage was brown, fetid pus. On microscopy, Trichomonad was detected in the pleural effusion. On a gene test, Tetratrichomonas sp. was identified. Based on this experience, we propose that non-stained specimens should be examined to detect Trichomonad on a puncture fluid test. (Case report).

[A case of osteomyelitis caused by mixed infection by Aggregatibacter aphrophilus and Staphylococcus aureus]

A 46-year-old man presented with a 10-day history of progressive weakness and numbness in both his legs. The spinal MRI and abdominal CT revealed discitis of L4/L5 and multiple epidural abscesses. The blood culture tested positive for methicillin sensitive Staphylococcus aureus (MSSA). The Gram stain of sample from abscess drainage showed Gram-positive cocci in clusters and small Gram-negative rods. The Gram-positive cocci in clusters were identified as MSSA using a general culture method and the small Gram-negative rods were identified as Aggregatibacter aphrophilus using a 16s ribosomal RNA sequencing method. The patient was treated four times with surgical abscess drainages and a long course of intravenous antibiotics therapy following which he recovered. No case of mixed infection by A. aphrophilus and S. aureus has been reported in MEDLINE; therefore, our case should be the first case report. Since we confirmed not only Gram-positive cocci in clusters but also Gram-negative rods in the abscess sample, we did not stop the identification procedure at the point when MSSA was identified and finally identified A. aphrophilus with 16s ribosomal RNA sequencing. Especially, in a mixed infection with organisms whose growth speed is different, an organism with slow growth might be missed if the Gram stain of sample were skipped. This case implies the significance of Gram staining as the identification procedure for organisms.

[A retrospective study of the relationship between bacterial numbers from central venous catheter tip cultures and blood cultures for evaluating central line-associated bloodstream infections]

Catheter-related bloodstream infection (CRBSI) is an infectious disease requiring special attention. It is a common cause of nosocomial infections; catheter insertion into the central veins particularly increases the risk of infection (CLA-BSI: central line-associated bloodstream infection). We examined the relationship between the number of bacterial colonies cultured from shredded central venous catheter (CVC) tips and from blood cultures in our hospital from 2011 to 2012. Coagulase-negative staphylococci topped the list of microbe isolated from the CVC tip culture, followed by Pseudomonas aeruginosa, Staphylococcus aureus, and Candida spp. S. aureus and Candida spp., with growth of over 15 colony-forming units in the CVC tip culture, were also detected at high rates in the blood culture. However, gramnegative bacilli (Enterobacteriaceae and P. aeruginosa) did not show a similar increase in colony number in the CVC tip culture. Because microbes adhering to shredded catheter tips are readily detected by culture, this method is useful as a routine diagnostic test. In addition, prompt clinical reporting of the bacterial number of serious CLA-BSI-causing S. aureus and Candida spp. isolated from CVC tips could contribute to earlier CLA-BSI diagnosis.