Koichi Yamada

Two unusual cases of successful treatment of hypermucoviscous Klebsiella pneumoniae invasive syndrome

BackgroundA few Japanese cases of hypermucoviscous Klebsiella pneumoniae (K. pneumoniae) invasive syndrome have recently been reported. Although extrahepatic complications from bacteremic dissemination have been observed, infected aneurysms are rare. Furthermore, the primary source of infection is generally a liver abscess, and is rarely the prostate. Therefore, we report two atypical cases of hypermucoviscous K. pneumoniae invasive syndrome.Case presentationThe first case was an 81-year-old Japanese man with no significant medical history, who was referred to our hospital for vision loss in his right eye. Contrast-enhanced whole-body computed tomography revealed abscesses in the liver and the prostate, and an infected left internal iliac artery aneurysm. Contrast-enhanced head magnetic resonance imaging revealed brain abscesses. Cultures of the liver abscess specimen and aqueous humor revealed K. pneumoniae with the hypermucoviscosity phenotype, which carried the magA gene (mucoviscosity-associated gene A) and the rmpA gene (regulator of mucoid phenotype A). We performed enucleation of the right eyeball, percutaneous transhepatic drainage, coil embolization of the aneurysm, and administered a 6-week course of antibiotic treatment. The second case was a 69-year-old Japanese man with diabetes mellitus, who was referred to our hospital with fever, pollakiuria, and pain on urination. Contrast-enhanced whole-body computed tomography revealed lung and prostate abscesses, but no liver abscesses. Contrast-enhanced head magnetic resonance imaging revealed brain abscesses. The sputum, urine, prostate abscess specimen, and aqueous humor cultures revealed K. pneumoniae with the hypermucoviscosity phenotype, which carried magA and rmpA. We performed enucleation of the left eyeball, percutaneous drainage of the prostate abscess, and administered a 5-week course of antibiotic treatment.ConclusionsHypermucoviscous K. pneumoniae can cause infected aneurysms, and the prostate can be the primary site of infection. We suggest that a diagnosis of hvKP invasive syndrome should be considered in all patients who present with K. pneumoniae infection and multiple organ abscesses.

Clinical Characteristics of Bacteremia Caused by Extended-spectrum Beta-lactamase-producing Escherichia coli at a Tertiary Hospital

Objective In recent years, infection caused by extended-spectrum beta-lactamase (ESBL)-producing organisms has become an important issue. However, comparative studies of the bacteremia caused by ESBL Enterobacteriaceae and non-ESBL Enterobacteriaceae are extremely rare in Japan. This study aimed to assess the risk factors and prognosis of patients with bacteremia due to ESBL Escherichia coli (E. coli). Methods The medical records of 31 patients with ESBL E. coli bacteremia and 98 patients with non-ESBL E. coli bacteremia who had been admitted to Osaka City University Hospital between January 2011 and June 2015 were retrospectively reviewed. The patient backgrounds, risk factors for infection, and prognosis were evaluated. Results The male-to-female ratio, mean age, underlying disease, leukocyte count, and C-reactive protein (CRP) level did not differ between the patients in the ESBL E. coli bacteremia and non-ESBL E. coli bacteremia groups. The mean Sequential Organ Failure Assessment (SOFA) score for patients with ESBL and non-ESBL E. coli bacteremia were 3.6 and 3.8, respectively. Further, the mortality did not differ between the two groups (9.7% vs 9.2%). However, the independent predictors associated with ESBL E. coli bacteremia according to a multivariate analysis were the use of immunosuppressive drugs or corticosteroids (p=0.048) and quinolones (p=0.005) prior to isolation. The mortality did not differ between the carbapenem and tazobactam/piperacillin (TAZ/PIPC) or cefmetazole (CMZ) groups for the patients with ESBL E. coli bacteremia. Conclusion Whenever we encountered patients with a history of immunosuppressive drug, corticosteroid, quinolone administration, it was necessary to perform antibiotic therapy while keeping the risk of ESBL E. coli in mind.

Effectiveness of weekly polymerase chain reaction-based open reading frame typing analysis of all newly isolated methicillin-resistant Staphylococcus aureus strains for controlling nosocomial infections

Polymerase chain reaction (PCR)-based open reading frame typing (POT) helps differentiate between bacterial strains based on the open reading frames (ORFs) of the prophage-encoding genes; multiplex PCR screening is performed to identify strains based on keeping patterns. At our hospital, surveillance of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) transmission is undertaken using POT to conduct molecular epidemiological analysis for all newly detected MRSA strains. In 2014, we performed POT only once a month; however, in 2015, we increased the frequency of POT to once a week, which helped us detect nosocomial transmission that would normally be difficult to detect, and thus achieve 40% reduction in nosocomial transmission, compared to that in 2014. This suggests that weekly POT screening for all MRSA strains is one of the effective methods available for minimizing nosocomial transmission of MRSA.

Clinical Characteristics of Methicillin-resistant Coagulase-negative Staphylococcal Bacteremia in a Tertiary Hospital

Objective Coagulase-negative staphylococci are among the most frequently isolated microorganisms in blood cultures. The aim of this study was to assess [1] the clinical characteristics of methicillin-resistant, coagulase-negative staphylococci bacteremia and [2] the susceptibility of the isolated bacteria to glycopeptides. Methods We retrospectively reviewed the medical records of 70 patients from whom methicillin-resistant coagulase-negative staphylococci had been isolated at Osaka City University Hospital between January 2010 and December 2013. We evaluated the patients background, severity and prognosis of the disease, and the susceptibility of the isolated methicillin-resistant coagulase-negative staphylococci to glycopeptides. Results Out of the 70 patients tested, 28 (40.0%) had leukemia, and 36 (51.4%) had been treated for febrile neutropenia. Infection with Staphylococcus epidermidis accounted for 78.6% of patients. Thirty-nine cases (55.7%) were related to intravascular catheters, and 39 (55.7%) were treated using teicoplanin as a first-line therapy. The 30-day mortality rate was 4.3%. Regarding susceptibility, 20% of all isolates were non-susceptible to teicoplanin. According to multivariate analyses, it was observed that premedication using glycopeptides was independently associated with teicoplanin non-susceptibility (p=0.03; hazard ratio = 5.64; 95% confidence interval, 1.16-26.76). Conclusion Our results suggest that clinicians must use glycopeptides appropriately to prevent the development of further antibiotic resistance in methicillin-resistant coagulase-negative staphylococci.

National Trends in the Distribution of Candida Species Causing Candidemia in Japan from 2003 to 2014: A Report by the Epidemiological Investigation Committee for Human Mycoses in Japan

The Epidemiological Investigation Committee for Human Mycoses in Japan performed a retrospective epidemiological survey of candidemia and causative Candida species. Data from 2003 to 2014 were collected from 10 Japanese university hospitals. A total of 328,318 blood cultures were included. The prevalence of fungi in all cultures and in positive cultures were 0.58±0.09% and 4.46±0.66%, respectively. Among the results that were positive for Candida species (N=1,921), Candida albicans was the most common species (39.5%) and was followed by Candida parapsilosis (23.3%), Candida glabrata (13.2%), Candida tropicalis (7.1%), Candida krusei (3.2%), and others (13.7%). During the last 6 years, the frequency of C. albicans has significantly decreased in Japan, while that of C. glabrata has increased. Additional surveys are needed to continuously monitor the trends in the distribution of candidemia.

Successful Treatment of Intestinal Mycosis Caused by a Simultaneous Infection with Lichtheimia ramosa and Aspergillus calidoustus

A 53-year-old woman was hospitalized due to septic shock after developing pneumococcal pneumonia after undergoing esophageal cancer surgery. Her transverse colon became perforated after receiving antimicrobial chemotherapy; therefore, emergency subtotal colectomy was performed. Fungi detected in both her colon tissue and a drainage sample indicated intestinal mucormycosis. Early intensive treatment with high-dose liposomal amphotericin B was successful, and she was subsequently discharged from the hospital. The fungal isolates were identified to be Lichtheimia ramosa and Aspergillus calidoustus via gene sequencing using panfungal primers as well as species-specific primers against elongation factor 1 and beta-tubulin for detecting Lichtheimia and Aspergillus, respectively.

Genome Sequence of an Acinetobacter baumannii Strain Carrying Three Acquired Carbapenemase Genes

ABSTRACT The emergence of multiple-carbapenemase-producing Acinetobacter strains has been a serious concern during the past decade. Here, we report the draft genome sequence of an Acinetobacter baumannii strain isolated from a Japanese patient with three acquired carbapenemase genes: blaNDM-1, blaTMB-1, and blaOXA-58.

Effectiveness of antibacterial prophylaxis with non‐absorbable polymyxin B compared to levofloxacin after allogeneic hematopoietic stem cell transplantation

Fluoroquinolones are widely used for antibacterial prophylaxis during neutropenia following hematopoietic stem cell transplantation (HSCT). Nevertheless, data are inadequate as to whether fluoroquinolones decrease mortality rate compared with other antibiotics.