Yasutaka Mizuno

Detection of Dengue Virus Genome in Urine by Real-Time Reverse Transcriptase PCR: a Laboratory Diagnostic Method Useful after Disappearance of the Genome in Serum

ABSTRACT The reemergence of dengue virus (DENV) infection has created a requirement for improved laboratory diagnostic procedures. In this study, DENV genome detection in urine was evaluated as a diagnostic method. The DENV genome was detected by real-time reverse transcriptase PCR (RT-PCR) in urine and serum of dengue patients. The detection rate of DENV genome in urine was 25% (2/8) on disease days 0 to 3 and 32% (7/22) on days 4 to 5. The rate was 50% or higher on days 6 to 16, 52% (11/21) on days 6 to 7, 78% (7/9) on days 8 to 9, 80% (4/5) on days 10 to 11, 50% (2/4) on days 12 to 13, and 60% (3/5) on days 14 to 16. The last positive urine sample was on day 16. The detection rates in serum were highest on days 0 to 3 and were greater than 50% on days 0 to 7. Detection rates decreased thereafter, and the last positive detection was on day 11. These results indicate that the time frames for positive detection differ between urine and serum samples, whereby detection rates of 50% or higher are evident between days 6 to 16 for urine samples and days 0 to 7 for serum samples. Nucleotide sequences of PCR products were identical between urine and serum samples. The detection of DENV genome in urine samples by real-time RT-PCR is useful to confirm DENV infection, particularly after viremia disappears.

A first case of New Delhi metallo-β-lactamase-7 in an Escherichia coli ST648 isolate in Japan

We report a first identification case of an Escherichia coli ST648 isolate producing a variant New Delhi metallo-β-lactamase (NDM) -7 in Japan, which was recovered from a patient hospitalized in India. Although the first isolate, NDM-1, was identified in Japan in 2010, NDM-producing bacteria have only been isolated from seven patients to date, and no other variant of NDM producing organism has been reported yet. The emergence of NDM variants in Enterobacteriaceae is of great concern, and the use of rigorous screening tests and preventive measures against infection is imperative.

Vertebral osteomyelitis caused by non-tuberculous mycobacteria: case reports and review

There are currently few reports of vertebral osteomyelitis caused by non-tuberculous mycobacteria. To date, only 38 cases, excluding human immunodeficiency virus patients, have been reported. We describe 3 patients with vertebral osteomyelitis caused by Mycobacterium avium-intracellulare complex or Mycobacterium kansasii, and review previous reports of vertebral osteomyelitis caused by non-tuberculous mycobacteria. Case 1 is a 50-year-old man who presented with lower back pain. Radiologic examination revealed L1–L5 enhancement and paravertebral abscess. The surgical specimen was positive for Mycobacterium avium-intracellulare complex. The patient was successfully treated by surgical excision and antibiotic administration. Case 2 is a 68-year-old woman who presented with upper back pain. Spine MRI revealed multiple lesions at T9–T12, L2, L4, and L5. Her back pain worsened, and repeated MRI revealed extensive bone lesions. Mycobacterium kansasii was isolated from a T5 vertebral body specimen. Surgery was not performed. Case 3 is a 38-year-old woman who had been taking prednisolone for systemic lupus erythematosus. We diagnosed her condition as suppurative knee arthritis caused by M. avium-intracellulare complex. Vertebral MRI revealed T9 vertebral body enhancement and a paravertebral abscess at T8–T9. Tissue culture of a T9 specimen yielded M. avium-intracellulare complex. Her clinical condition improved following posterior thoracic spinal fusion. In conclusion, vertebral osteomyelitis caused by non-tuberculous mycobacteria should be included in the differential diagnosis, even in immunocompetent patients.

Fulminant colitis from Clostridium difficile infection, the epidemic strain ribotype 027, in Japan.

In December 2012, a 32-year-old woman with no previous medical history and no previous antibiotic treatment had a fever and diarrhea 2 days after a cesarean section in which cefazolin was used as a prophylactic antimicrobial agent. She was transferred to our hospital 5 days after the cesarean for severe colitis. A rapid test of stool for Clostridium difficile toxin A and B was positive. Although oral vancomycin (0.5-2.0 g/day) and intravenous immunoglobulin (5 g/day) were administered after her transfer, 7 days after admission emergency exploratory surgery was performed because of poor response to therapy. Bowel perforation was noted and a temporary colostomy was created without colectomy. Vancomycin (2.0 g/day) was administered via the colostomy, in addition to a vancomycin enema (2.0 g/day), oral metronidazole (1500 mg/day), and oral vancomycin (2.0 g/day). Three days after the operation, linezolid (1200 mg/day IV) was added. She was treated with antibiotics against C. difficile for a total of 18 days after the operation. The same strain was not isolated from other patients in the same ward. Microbiological analysis of the isolate revealed housekeeping gene (tpi), toxin A gene (tcdA), toxin B gene (tcdB), and binary toxin gene (cdtA and cdtB). DNA sequencing of tcdC revealed a base 117 deletion and contained an 18-bp tcdC deletion. PCR ribotyping showed ribotype 027 patterns. The MIC of moxifloxacin was >32 μg/ml, indicating resistance to fluoroquinolones. This isolate was considered as the epidemic strain. Our case of fulminant colitis is apparently the first case involving the epidemic strain ribotype 027 in Japan.

First case report of vancomycin-intermediate sequence type 72 Staphylococcus aureus with nonsusceptibility to daptomycin

BackgroundSequence type 72 methicillin-resistant Staphylococcus aureus (MRSA) SCCmec type IV (ST72-MRSA-IV) is the most common community-acquired MRSA clone in Korea. Resistance to daptomycin or vancomycin among community-acquired MRSA clones is not well described in the literature. We herein report the first case of vancomycin-intermediate, daptomycin-nonsusceptible ST72-MRSA-IV.Case presentationA 45-year-old Japanese man underwent aortic arch prosthesis implantation for treatment of a dissecting aortic aneurysm. Fourteen months later, he developed a prosthetic graft infection of the aortic arch and an anterior mediastinal abscess caused by ST72-MRSA-IV. First-line treatment with vancomycin and rifampicin failed, and daptomycin was thus administered. After several days, the treatment was changed to linezolid because of the re-emergence of fever. The patient’s condition resolved and no recurrence or other problems were seen for 1 year post-treatment. The infectious agent was definitively identified as vancomycin-intermediate, daptomycin-nonsusceptible, rifampicin-resistant ST72-MRSA-IV based on culture results and minimum inhibitory concentration testing.ConclusionThis case report illustrates the importance of fully understanding the changing epidemiology of infectious agents and the risk factors for the development of antibiotic resistance. Such information will help to minimize the emergence and spread of antibiotic-resistant strains. This report concerns one particular bacterial strain; however, the basic concepts involved in this case translate to all infectious disease fields.

Extended-spectrum β-lactamase-producing Enterobacteriaceae colonisation in long-term overseas business travellers.

BACKGROUND International travel is considered a risk for colonisation with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE). To our knowledge, no studies to date have focused on ESBL-PE colonisation among long-term business travellers. Therefore this study aimed to clarify the characteristics associated with ESBL-PE colonisation in Japanese long-term business travellers. METHODS Japanese business travellers planning to stay abroad for ≥6 months were enrolled. Of the 192 travellers, 135 provided only post-travel stool samples and 57 provided both pre- and post-travel stool samples. Additionally, microbiological analyses of ESBL-PE strains, including susceptibility tests and polymerase chain reaction amplification of CTX-M genes and their sequencing were performed. RESULTS A post-travel survey showed that of the 55 travellers (40.7%) who tested positive for ESBL-PE after travel, the highest proportion was travellers returning from East and Central Asia. CTX-M gene analyses showed that CTX-M-15 was the most frequently observed (55.0%). A pre- and post-travel survey showed that of the 22 travellers (44.9%) acquired ESBL-PE during their travel, with acquisition most frequently observed in travellers returning from South Asia. CONCLUSION Risk-based evaluations of ESBL-PE colonisation should be performed not only for regular tourists but also for long-term business travellers.

Strongyloides stercoralis Infection Causing Obstructive Jaundice and Refractory Pancreatitis: A Lesson Learned from a Case Study.

A 58-year-old Japanese woman came to our institution because of leg edema and abdominal distention. She had developed acute pancreatitis 5 times in the past 3 years. Dilation of the bile duct and main pancreatic duct without obstruction was observed on computed tomography and magnetic resonance cholangiopancreatography. The presence of Strongyloides stercoralis was highly suspected from the biopsy sample from the duodenal papilla. Polymerase chain reaction amplification and sequencing of small subunit rDNA from paraffin-embedded specimens identified the worm as S. stercoralis. All of the symptoms were considered to be associated with S. stercoralis infection. Therefore, the patient was treated with oral administration of ivermectin. Subsequently, symptoms and laboratory data improved. There has been no recurrence of the symptoms to date.

Case Series of Imported Enteric Fever at a Referral Center in Tokyo, Japan: Antibiotic Susceptibility and Risk Factors for Relapse

Owing to the increase in Salmonella strains with decreased fluoroquinolone susceptibility in the endemic areas, we have been treating enteric fever with intravenous ceftriaxone empirically since 2007. In this study, we reevaluated our treatment protocol. This retrospective cohort study was conducted at a single institute in Tokyo, Japan, between January 2006 and December 2013. Enteric fever was defined as isolation of Salmonella Typhi or Salmonella Paratyphi A, B, and C from the blood and/or stool of patients with fever. Of the 35 patients with imported enteric fever, 28 (80%) had returned from south Asia. Ciprofloxacin-susceptible strains were detected in only 12% of the cases. The isolates showed excellent susceptibility to ampicillin (91%), chloramphenicol (94%), ceftriaxone (97%), and azithromycin (97%). One case of Salmonella Paratyphi B was excluded, and of the remaining 34 patients, 56% were treated with ceftriaxone alone, 26% with ceftriaxone then fluoroquinolone, and 9% with levofloxacin alone. The overall relapse rate was 6.1%; however, among those receiving ceftriaxone monotherapy, the relapse rate was 11% (N = 2). The relapse group was characterized by longer times to treatment initiation (P = 0.035) and defervescence (> 7 days) after treatment initiation (P = 0.022). In such cases, we recommend that ceftriaxone treatment be continued for > 4 days after defervescence or be changed to fluoroquinolone if the strains are found to be susceptible to prevent relapse. Furthermore, ampicillin and chloramphenicol, which are no longer prescribed, may be reconsidered as treatment options in Asia.

An attempt to support by the Japanese society of travel and health for increasing travel clinics

Abstract In recent years, both the number of Japanese travelers to foreign countries and foreign travelers who visit Japan have increased remarkably, and the risk of travelers suffering various infectious diseases is also increasing. In many western countries travel clinics commonly perform medical consultations, vaccinations, and issue prescriptions. However, travel clinics are not yet popular in Japan. In 2011, Japanese society of travel and health (JSTH) began a support project for travel clinic with a goal of increasing their number throughout the country. The project included the release of a manual for education, training, equipment, details of medical treatment, sources of information for travel clinic opening on the JSTH website (http://jstah.umin.jp/20TravelClinicSupport/manual_20120726.pdf), and mediation of short-term visitation to experienced travel clinics registered in the JSTH to facilitate learning above information and aftercare services. JSTH accepted requests for visitation to travel clinics from 39 medical institutions between 2011 and 2018. By 2018, 26 (66.7%) of the 39 medical institutions had opened travel clinics within two years and the 25 travel clinics had registered in the JSTH and one was a campus-limited clinic, while most of the remaining institutions are still in preparation stages. The number of travel clinics registered in the JSTH has increased from 45 in 2011 to 108 in 2018. Twenty-five travel clinics registered in the JSTH between 2011 and 2018 were eventually receiving support from JSTH. Our data indicates travel clinics in Japan have gradually increased and establishment areas are expanding after the beginning of support project for travel clinics by JSTH.

Neurocysticercosis with Diplopia Responds Well to Albendazole

We report a case of neurocysticercosis concurrent with taeniasis in a 31-year-old woman. The patient presented with a headache and diplopia. Oculomotor disturbances with a left adduction deficit were observed. Fundoscopy revealed papilledema. Additionally, computed tomography of the brain revealed more than 20 small cysts within the parenchyma, most of which were associated with ring enhancement. Moreover, serum antibody testing (Western blotting) for Taenia solium-cysticerci was positive. The patient received albendazole and corticosteroids, and progressive resolution of the neurological symptoms and papilledema was observed starting approximately three days after administration. This patient has been asymptomatic for more than one year.