An outbreak of Legionella pneumonia originating from a cooling tower

We report 2 cases of Legionella pneumonia in individuals who were exposed to aerosols during maintenance of a cooling tower at a waste processing plant. This report documents the first known occupation-related outbreak of Legionella pneumonia in Japan.     

Detection of antibody against antigen expressed by molecularly cloned hepatitis C virus cDNA: application to diagnosis and blood screening for posttransfusion hepatitis.

A cDNA clone has been derived from the plasma of a chimpanzee with chronic non-A, non-B viral hepatitis (NANBH). We have assayed for antibodies reacting with the encoded antigen in sera from posttransfusion hepatitis patients (643 samples from 23 patients) and their corresponding donors collected during the past 10 years in Japan. The antibody was detected in 15 out of 17 (88.2%) posttransfusion NANBH (PT-NANBH) patients whose sera over time displayed multiple alanine aminotransferase (ALT) peaks. In general, the antibody was detected after several peaks of serum ALT elevations and, once detected, it persisted for years. In contrast to the patients of chronic hepatitis, the antibody was barely detected in patients with a single episode of ALT elevation (1 out of 6). Of the 15 well-defined cases of PT-NANBH that showed multiple ALT peaks and hepatitis C virus seroconversions, 11 (73.3%) were shown to be transfused with at least one unit of blood positive for the antibody. The retrospective analysis showed that all tested donor blood found to be positive for the antibody had been transfused to recipients who afterwards developed NANBH. These data strongly suggest that the cloned cDNA originated from an etiological agent of NANBH termed the hepatitis C virus. Furthermore, the present study demonstrates that had the screening been done with the anti-hepatitis C virus assay, 11 out of 17 (64.7%) cases of chronic PT-NANBH and 1 out of 6 (16.6%) acute PT-NANBH would have been prevented. The antibody assay thus can be used for diagnosis and blood screening for PT-NANBH.     

Change in antimicrobial susceptibility of pathogens isolated from surgical site infections over the past decade in Japanese nation-wide surveillance study

Inappropriate antimicrobial therapy for surgical site infections (SSIs) can lead to poor outcomes and an increased risk of antibiotic resistance. A nationwide survey was conducted in Japan from 2018 to 2019 to investigate the antimicrobial susceptibility of pathogens isolated from SSIs. The data were compared with those obtained in 2010 and 2014–2015 surveillance studies. Although the rate of detection of extended-spectrum β-lactamase producing strains of Escherichia coli was increased from 9.5% in 2010 to 23% in 2014–2015, the incidence decreased to 8.7% in 2018–2019. Although high susceptibility rates were detected to piperacillin/tazobactam (TAZ), the geometric mean MICs were substantially higher than to meropenem (2.67 vs 0.08 μg/mL). By contrast, relatively low geometric mean MICs (0.397 μg/mL) were demonstrated for ceftolozane/TAZ. Although the MRSA incidence rate decreased from 72% in the first surveillance to 53% in the second, no further decrease was detected in 2018–2019. For the Bacteroides fragilis group species, low levels of susceptibility were observed for moxifloxacin (65.3%), cefoxitin (65.3%), and clindamycin (CLDM) (38.9%). In particular, low susceptibility against cefoxitin was demonstrated in non-fragilis Bacteroides, especially B. thetaiotaomicron. By contrast, low susceptibility rates against CLDM were demonstrated in both B. fragilis and non-fragilis Bacteroides species, and a steady decrease in susceptibility throughout was observed (59.3% in 2010, 46.9% in 2014–2015, and 38.9% in 2018–2019). In conclusion, Japanese surveillance data revealed no significant lowering of antibiotic susceptibility over the past decade in organisms commonly associated from SSIs, with the exception of the B. fragilis group.     

Evaluation of Streptococcus pneumoniae-urinary antigen detection kit in patients with community acquired pneumonia

We evaluated a new rapid urinary antigen detection kit. NOW Streptococcus pneumoniae (Binax Inc., USA) that detected S. pneumoniae antigen by immunochromatographic membrane assay, with 66 Japanese adult patients of community acquired pneumonia. Twenty-two (33.3%) patients were found to be positive with the kit and S. pneumoniae was isolated from six patients (27.3%) of these 22 patients. S. pneumoniae was not isolated from eight of the 22 patients by blood or sputum culture. Analysis of clinical laboratory data showed that the levels of C-reactive protein (CRP) in the serum were significantly higher in the urine-antigen positive group than those in the urine-antigen negative group. There were no significant difference between the two groups including renal function, urinalysis, clinical symptom, and severity of pneumonia. Our study suggests that more cases of community acquired pneumonia are caused by S. pneumoniae than conventional tests can currently confirm. Since it is not technically complex, does not require equipment, and detects within as quickly as in 15 minutes, the S. pneumoniae urinary antigen kit is useful for rapid diagnosis of community acquired pneumonia in adults.     

Treatment of oral ranula in HIV-positive patient

HIV-associated salivary gland disease refers to the pathology in head and neck lesions such as ranula, salivary gland swelling, xerostomia, and benign lymphoepithelial cysts in the parotid gland. Here, we present a unique case of the ranula patient with HIV infection treated with OK-423 sclerotherapy. Case report: The patient was a 42-year-old Japanese male with a few months history of oral floor swelling. Computed tomography (CT) showed a low-density area limited within the right floor of the mouth. Magnetic resonance imaging (MRI) revealed a distinct T2-high intensity area localized on the same location. The puncture fluid was bloody mucus, and the cytology was no malignancy. We diagnosed a simple ranula. He was, however, found to be HIV-antibody positive at the examination before treatment by chance. He was referred to the department of infectious diseases and definitively diagnosed HIV infection by western blot. We chose OK-432 sclerotherapy because of its minimally invasive and the risk of HIV infecting medical staff. Two times OK-432 injection made the lesion disappear. Conclusion: The case indicated that OK-432 sclerotherapy could be effective for ranula related to HIV.     

In vitro and in vivo evaluation of DU6859a,a new fluoroquinolone,among injectable antibacterials tested against clinical isolates

DU6859a was evaluated for its in vitro and in vivo antibacterial activities in comparison with those of imipenem, meropenem, cefpirome, vancomycin, gentamicin, ciprofloxacin and levofloxacin. DU6859a had activity comparable to that of imipenem against methicillin-susceptible staphylococci and penicillin-susceptible and-resistantStreptococcus pneumoniae, with MICs at which 90% of strains tested are inhibited (MIC₉₀)≤0.063μg/mL. Against methicillin-resistant staphylococci and enterococci, DU6859a was as active as vancomycin and more active than other drugs tested, with MIC₉₀s ranging from 1 to 4 μg/mL. DU6859a was as active as ciprofloxacin and more active than other drugs tested against imipenem-resistantPseudomonas aeruginosa. Differences in activity between DU6859a and reference drugs against ciprofloxacin-resistant and gentamicin-resistantP. aeruginosa were particularly striking. The in vivo efficacy of subcutaneous injections of DU6859a against experimental septicemia, respiratory and pyelonephritic infections caused by gram-positive and-negative bacteria, including methicillin-resistantStaphylococcus aureus and imipenem-resistantP. aeruginosa, reflected its potent in vitro activity.     

The first recognized patient withLegionella pneumophila serogroup 9 pneumonia in Japan

A 77-year-old female was admitted because of high fever, cough and sputum. She had been receiving corticosteroid therapy for 4 years for multiple myeloma and was immunosuppressed. A physical examination on admission showed coarse crackles in the right lower lung field, a chest radiograph showed consolidation in the right middle and lower lung fields, and a blood gas analysis revealed marked hypoxemia. The patient was diagnosed as having refractory pneumonia associated with acute respiratory failure and treated with intravenous cefmetazole followed by imipenem. On hospital day 5, erythromycin therapy was started because of a poor response to the previous antibiotics. The patient became afebrile on the tenth day and was in good health on day 15. A sputum culture on day 4 revealed aLegionella organism on Wadowsky-Yee-Okuda medium, which was subsequently confirmed to beLegionella pneumophila by a DNA hybridization test. This strain was identified at the Centers for Disease Control (Atlanta, GA, USA) by slide agglutination asL. pneumophila serogroup 9. Although our patient's symptoms are not apparently different from those caused by other serogroup strains ofL. pneumophila, this is the first recognized patient with culture-provenL. pneumophila serogroup 9 pneumonia in Japan. The clinical course of the disease and the diagnostic difficulties in identifying this type of pneumonia are discussed.