A case of community-acquired Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (MRSA) necrotizing pneumonia successfully treated with two anti-MRSA drugs.

A 22-year-old Vietnamese man was referred to our hospital owing to cough, dyspnea, and difficulty moving. The patient was diagnosed with community-acquired Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and necrotizing pneumonia. Treatment involved vancomycin (VCM) and meropenem, and the MRSA bacteremia improved. However, lung tissue destruction progressed. Therefore, linezolid was added to the VCM regimen, and this intervention led to the patient's recovery, and he was discharged from the hospital. Here, we report a case in which the patient was treated with a combination of two anti-MRSA drugs and was cured.

The incidence and prognosis of other iatrogenic immunodeficiency-associated lymphoproliferative disorders of the lung related to methotrexate: A retrospective study.

BACKGROUND AND OBJECTIVE: Other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPD) are rare but well-known diseases that manifest during or after methotrexate (MTX) administration. Limited information is available on the clinical characteristics of OIIA-LPD of the lung because only a few cases have been reported. Thus, we aimed to assess the incidence and prognosis of patients with OIIA-LPD of the lung. METHODS: Patients with OIIA-LPD of the lung treated at our institution between January 2008 and July 2020 were retrospectively analysed. RESULTS: Among the 51 patients with OIIA-LPD, 16 (31.3%, 7 men, 9 women) had OIIA-LPD of the lung (median age, 69 [range, 63-82] years). Peripheral lesions were observed in 10 (62.5%), central lesions in two (12.5%), and both lesions in four (25.0%) patients. Nine of the 16 patients underwent bronchoscopic biopsy, seven were diagnosed (diagnostic yield, 77.8%) and, re-biopsy was performed in 2 patients. Eight (50.0%) patients had LPD and six (37.5%) had diffuse large B-cell lymphoma. In the 14 patients with confirmed treatment efficacy, the overall response rate to MTX withdrawal was 71.4%. However, chemotherapy was required in case of larger lesions (three patients). Death related to OIIA-LPD occurred in only one patient, and 11 of the 14 patients were alive during the study period (median follow-up time, 53.7 [range, 4.3-84.2] months). CONCLUSION: The incidence of OIIA-LPD of the lung is 31.3% and higher than that reported previously. The treatment effect of MTX withdrawal seems to be sufficient; however, in some cases, chemotherapy may be required from the beginning.

Ultrathin bronchoscopic cryobiopsy of peripheral pulmonary lesions.

BACKGROUND AND OBJECTIVE: Ultrathin bronchoscopy aids in the diagnosis of peripheral pulmonary lesions. However, both the working channel and the specimens are small. A 1.1-mm ultrathin cryoprobe that can enter the working channel of the ultrathin bronchoscope is now available, which may overcome the limitations of small specimen size. The aim of this study was to evaluate the feasibility, efficacy and safety of ultrathin bronchoscopic cryobiopsy using an ultrathin cryoprobe for diagnosing peripheral pulmonary lesions. METHODS: Patients with peripheral pulmonary lesions ≤30 mm in diameter were prospectively enrolled in the study. All patients underwent forceps biopsy followed by cryobiopsy using a 3.0-mm ultrathin bronchoscope under radial probe endobronchial ultrasound guidance, virtual bronchoscopic navigation and fluoroscopic guidance. The primary endpoint was the feasibility of cryobiopsy. RESULTS: In total, 50 patients with peripheral pulmonary lesions were enrolled in the study; the median longest diameter on computed tomography was 17.9 mm. Cryobiopsy was performed successfully in 49 patients (98%). Forceps biopsy, cryobiopsy and the combination of these two methods provided a specific diagnosis in 54% (27/50), 62% (31/50) and 74% (37/50) of patients, respectively. The median size of specimens obtained via cryobiopsy was significantly larger than the median size obtained via forceps biopsy (7.0 vs. 1.3 mm2 , respectively, p < 0.001). Mild bleeding during cryobiopsy occurred in 47 patients (94%). No moderate/severe bleeding or pneumothorax occurred. CONCLUSION: Ultrathin bronchoscopic cryobiopsy is feasible, effective and sufficiently safe for the diagnosis of peripheral pulmonary lesions.

EUS-B-FNA Enhances the Diagnostic Yield of EBUS Bronchoscope for Intrathoracic Lesions.

INTRODUCTION: Endobronchial ultrasound (EBUS) bronchoscopes have been used mainly through the airway for EBUS-guided transbronchial needle aspiration (EBUS-TBNA); however, they can also be used through the esophagus. The esophageal approach, endoscopic ultrasound with bronchoscope-guided fine needle aspiration (EUS-B-FNA), has gradually become popular, as it can evaluate lesions that cannot be accessed through the airway. PURPOSE: This study aimed to evaluate the value of adding EUS-B-FNA to EBUS-TBNA performed by pulmonologists for intrathoracic lesions in the clinical setting. METHODS: Between March 2009 and March 2020, all patients who underwent EUS-B-FNA and EBUS-TBNA for diagnostic purposes were included and retrospectively analyzed at a single institution. RESULTS: A total of 1794 procedures using an EBUS bronchoscope including, EBUS-TBNA, EUS-B-FNA, and the combination of EBUS-TBNA and EUS-B-FNA for evaluating intrathoracic lesions, were performed. We finally analyzed 276 patients who underwent EUS-B-FNA for diagnostic purposes. EUS-B-FNA provided diagnostic materials from only EBUS-TBNA-inaccessible lesions in 26 patients and in 18 patients whose conditions were inappropriate for bronchoscopy (e.g., respiratory failure, airway stenosis, etc.). EUS-B-FNA provided diagnostic results in four patients with non-diagnostic EBUS-TBNA results. EUS-B-FNA was preferable to EBUS-TBNA in 4.4% (48 of 1091) of patients; therefore, adding EUS-B-FNA to EBUS-TBNA increased the diagnostic yield from 72.6% (1043 of 1437) to 75.9% (1091 of 1437). CONCLUSION: Pulmonologists are able to enhance diagnostic yields by acquiring the EUS-B-FNA technique.

Thin bronchoscopic cryobiopsy using a nasobronchial tube.

BACKGROUND: Transbronchial lung cryobiopsy is useful when diagnosing lung lesions. However, prevention of associated bleeding complications is essential. This study aimed to evaluate the safety and efficacy of our novel bronchoscopic cryobiopsy technique, which uses a long nasobronchial tube to prevent blood flooding the central airway. METHODS: Patients with localized or diffuse lung lesions were prospectively enrolled and underwent cryobiopsy using a 1.9 mm diameter cryoprobe and a 4.0 mm diameter thin bronchoscope under conscious sedation. For cryobiopsy, a long silicone tube (inner diameter, 5.0 mm) was advanced through the nose to the target bronchus, then wedged to drain blood under thin-tube bronchoscopic control. The primary endpoint was the frequency of bleeding complications. RESULTS: Of the 80 patients initially enrolled, 73 that underwent at least one cryobiopsy were ultimately included. Mild bleeding during cryobiopsy occurred in 58 patients (79.5%), but there was no moderate or severe bleeding. Other complications occurred in four patients (two pneumothorax, one pneumomediastinum, and one pneumonia). Tube dislocation was noted in eight patients (11%). Cryobiopsy specimens were significantly larger than forceps biopsy specimens (9.0 mm2 vs. 2.7 mm2, P < .001) and allowed specific diagnoses in 50 patients (68.5%). CONCLUSIONS: Thin bronchoscopic cryobiopsy using a nasobronchial tube in consciously sedated patients is safe and effective. Trial registration Date of registration: 24/06/2019. UMIN-Clinical Trials Registry; Identifier: UMIN000037156 https://www.umin.ac.jp/ctr/index.htm.

Changes in Pulmonary Function Test Results and Respiratory Symptoms before and after Airway Stent Removal.

BACKGROUND: Airway stenting is a useful form of palliation for patients with airway stenosis/fistulas; the stent can be removed after addressing the cause of the airway disorder. Patients with airway stents often complain of coughing and difficulty with expectoration, so the use of such stents can negatively affect pulmonary function and worsen symptoms. OBJECTIVES: The aim of this study was to compare pulmonary function and respiratory symptoms before and after stent removal. METHODS: Patients who would later undergo simple airway stent removal were prospectively recruited in two institutions. All stents were removed using both rigid and flexible bronchoscopes with patients under general anesthesia. Pulmonary function tests were performed before stent removal and at 1 and 4 weeks after stent removal. All patients self-reported their respiratory symptoms using a 100-mm visual analog scale (VAS). RESULTS: Of the 31 patients enrolled, 28 (23 with malignant stenoses, 3 with benign stenoses, and 2 with fistulas [21 silicone and 7 metallic stents]) were included in analyses. Pulmonary function measurements before stent removal and at 1 and 4 weeks after stent removal were as follows: vital capacity, 3.00, 3.04, and 3.08 L (p = 0.387); forced expiratory volume in 1 s, 1.96, 1.96, and 2.12 L (p = 0.034); and peak expiratory flow, 3.60, 4.28, and 5.06 L/s, respectively (p < 0.001). Symptoms (cough, sputum production, difficulty with expectoration, and dyspnea) evaluated using the VAS improved significantly after stent removal. No complications were encountered during removal. CONCLUSION: Removal of unnecessary airway stents improves pulmonary function and respiratory symptoms. Any stent that is no longer functioning should be removed.

Safety and efficacy of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for patients aged 80 years and older.

BACKGROUND: The safety and efficacy of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in patients aged 70 years and older has been established. However, few studies have evaluated the safety, usefulness, and significance of EBUS-TBNA in patients aged 80 years and older. METHODS: We retrospectively investigated patients aged 80 years and older who underwent EBUS-TBNA under local anesthesia. The study period was 10 years; from November 1, 2010 to October 31, 2020. The primary endpoint was the safety of EBUS-TBNA, which was measured as the incidence of complications associated with the procedure. The secondary endpoints were the overall diagnostic rate, malignant disease diagnosis rate, and malignant disease treatment rate. RESULTS: A total of 111 patients were enrolled in the study, and the median age was 82 years (range: 80-89 years). The incidence of complications (the primary endpoint) was 5% (5/111) and comprised oversedation in one case, chest pain in one case, hypoxemia in two cases, and arrhythmia in one case. Regarding the secondary endpoints, the diagnostic rate for all patients was 75% (83/111), and the diagnostic rate of malignant disease was 89% (75/84). Of the 75 patients with malignant disease diagnosed with EBUS-TBNA, 61 (81%) received tumor-specific therapy in accordance with their diagnoses. CONCLUSION: EBUS-TBNA can be considered safe and effective even in patients aged 80 years and older.

The Role of Rigid Bronchoscopic Intervention for Bronchial Carcinoid.

Bronchial carcinoid is a rare malignant tumor that is categorized as a typical carcinoid or atypical carcinoid. Many institutions use flexible bronchoscopy for diagnosis. However, due to the hemorrhagic nature of the tumor, the amount of specimen obtained is often small, making it difficult to obtain an accurate diagnosis. The use of rigid bronchoscopy may not only contribute to obtaining a diagnosis but also be beneficial in the treatment plan. The aim of this study was to evaluate the efficacy of rigid bronchoscopic interventions for the diagnosis and treatment of bronchial carcinoids. All patients with bronchial carcinoids who underwent rigid bronchoscopic intervention under general anesthesia at our institution between June 2006 and August 2018 were analyzed retrospectively. Eight patients [3 men and 5 women; median age, 71 years (range 45-82 years)] were eligible for the analysis. None of the cases had accurate subtyping preoperatively before intervention. In contrast, all cases were diagnosed as carcinoid with subtypes (5 patients had typical carcinoid and 3 had atypical carcinoid) following rigid bronchoscopic intervention. All respiratory symptoms improved immediately after the procedure. One instance of bleeding occurred, and was easily controlled by argon plasma coagulation and intraluminal administration of epinephrine under flexible and rigid bronchoscopy. Four patients (3 with typical carcinoid and 1 with atypical carcinoid) underwent radical surgery sequentially, and no recurrences were observed. We conclude that rigid bronchoscopic intervention is safe and effective for accurate diagnosis and improvement of respiratory symptoms in patients with bronchial carcinoids.

Relevance of diffusion-weighted imaging with background body signal suppression for staging, prognosis, morphology, treatment response, and apparent diffusion coefficient in plasma-cell neoplasms: A single-center, retrospective study.

Accurate staging and evaluation of therapeutic effects are important in managing plasma-cell neoplasms. Diffusion-weighted imaging with body signal suppression magnetic resonance imaging (DWIBS-MRI) allows for acquisition of whole-body volumetric data without radiation exposure. This study aimed to investigate the usefulness of DWIBS-MRI in plasma-cell neoplasms. We retrospectively analyzed 29 and 8 Japanese patients with multiple myeloma and monoclonal gammopathy of undetermined significance, respectively, who underwent DWIBS-MRI. We conducted a histogram analysis of apparent diffusion coefficient values. The correlations between each histogram parameter and staging, cell maturation, prognosis, and treatment response were evaluated. We found that the apparent diffusion coefficient values in patients with monoclonal gammopathy of undetermined significance were lower than those in patients with multiple myeloma. Pretreatment apparent diffusion coefficient values of immature myeloma were lower than those of mature myeloma. Moreover, these values decreased in proportion to stage progression in Durie-Salmon classification system but showed no significant correlation with other staging systems or prognosis. Patients were stratified as responder, stable, and non-responder based on the International Myeloma Working Group criteria. The magnitude of changes in apparent diffusion coefficients differed significantly between responders and non-responders (0.154 ± 0.386 ×10-3 mm2/s vs. -0.307 ± 0.424 ×10-3 mm2/s, p = 0.003). Although its usefulness has yet to be established, DWIBS-MRI combined with apparent diffusion coefficient measurement allowed for excellent response evaluation in patients with multiple myeloma. Furthermore, apparent diffusion coefficient analysis using DWIBS-MRI may be useful in predicting cell maturation and total tumor volume.

Elevation of HHV-6 viral load mimicking HHV-6 reactivation after second umbilical cord blood transplantation in chromosomally integrated human herpesvirus-6.

Human herpesvirus-6 (HHV-6) reactivation is an important complication in patients receiving umbilical cord blood transplantation (CBT). Chromosomally integrated human herpesvirus-6 (ciHHV-6) is a condition in which the complete HHV-6 genome is integrated into the host germline genome and is transmitted in a Mendelian manner. The influence of ciHHV-6 in recipients or donors in cases of CBT is unknown. We report the first case with ciHHV-6 that received CBT twice for acute lymphoblastic T-cell leukemia. HHV-6 DNA in peripheral blood leukocytes (PBLs) was examined over time through two CBTs. After the first CBT, the HHV-6 viral load was significantly reduced by conversion to PBLs derived from the first donor. During the second CBT, an increase in HHV-6 DNA in PBLs and plasma were observed. However, HHV-6 mRNA was not detected in either the sample before 2nd CBT or at the time of HHV-6 DNA elevation. It is considered that the HHV-6 DNA detected in PBLs and plasma samples might be the HHV-6 genome released due to tissue damage. This case suggests that physicians should be aware of HHV-6 DNA variability during allogeneic hematopoietic stem cell transplantation in ciHHV-6 patients.

External fixation of airway stents for upper tracheal stenosis and tracheoesophageal fistula.

OBJECTIVES: Stent migration is a common complication of airway stent placement for upper tracheal stenosis and tracheoesophageal fistula. Although several researchers have reported that external fixation is effective in preventing stent migration, the usefulness and safety of external fixation have not been proved because their cohorts were small. We therefore investigated the efficacy and safety of external fixation during upper tracheal stenting. METHODS: Records of patients who underwent airway stent placement from May 2007 to August 2018 in a single centre were retrospectively reviewed. We included only patients whose stent had been placed in the upper trachea with external fixation to the tracheal wall. The primary endpoint of this study was the rate of stent migration. RESULTS: Altogether, 51 procedures were performed in 45 patients (32 males, 13 females; median age 60 years, range 14-91 years). The median follow-up period was 9 months (range 0.3-90 months). Among the procedures, 15 were performed for benign disease and 36 for malignancy. Stents were composed of either silicone (n = 42) or metal (n = 9). Stent migration occurred in 3 (6%) patients. The stents with migration were all composed of silicone. Other sequelae were granulation tissue formation in 10 (20%) patients, sputum obstruction in 6 (12%), cellulitis in 3 (6%) and pneumonia in 1 (2%). CONCLUSIONS: External fixation was an effective method for preventing migration of airway stents placed for upper tracheal stenosis and tracheoesophageal fistula. The complications were acceptable in terms of safety.

Successful cord blood transplantation for myelodysplastic syndrome complicated by Mycobacterium kansasii pneumonia.

Non-tuberculous mycobacterial (NTM) disease is a rare cause of neutropenic fever in patients with hematological malignancies. There are few studies on the optimal management for such patients with NTM. We report a case of myelodysplastic syndrome (MDS) treated by umbilical cord blood transplantation (CBT) after Mycobacterium kansasii (M kansasii) pneumonia. A 38-year-old man diagnosed with MDS developed severe pneumonia during induction chemotherapy. Repeated sputum culture uncovered mycobacterium infection. Then, by the polymerase chain reaction of the bronchial lavage fluid, M kansasii infection was proven. After 140 days of anti-NTM therapy, CBT was successfully carried out and the patient recovered without recurrence of NTM infection. This case provides valuable evidence that hematopoietic stem cell transplantation is feasible after a reliable diagnosis and continuous anti-NTM therapy.

Activities of matrix metalloproteinase-2, matrix metalloproteinase-9, and serine proteases in samples of the colorectal mucosa of Miniature Dachshunds with inflammatory colorectal polyps.

OBJECTIVE: To investigate the activities of gelatinases (matrix metalloproteinase [MMP]-2 and MMP-9) and serine proteases in the colorectal mucosa of Miniature Dachshunds (MDs) with inflammatory colorectal polyps (ICRPs). ANIMALS: 15 MDs with ICRPs and 5 dogs with non-ICRP-related large bowel diarrhea (controls). PROCEDURES: Zymographic methods were used to evaluate the activities of MMP-2, MMP-9, latent forms of MMP-2 and MMP-9 (pro-MMP-2 and pro-MMP-9), and serine proteases in inflamed and noninflamed tissue samples from MDs with ICRPs and in noninflamed tissue samples from control dogs. The associations of serine protease activities with MMP-2 or MMP-9 activity were also analyzed. RESULTS: Activities of pro-MMP-2 and pro-MMP-9 were detected in most tissue samples, regardless of the tissue type, whereas activities of MMP-2 and MMP-9 were not detected in control tissue samples. In the inflamed tissue samples from MDs with ICRPs, the activities of MMP-2, pro-MMP-9, and MMP-9 were significantly higher than those in the noninflamed tissue samples from those dogs. Serine protease activities were significantly higher in the inflamed and noninflamed tissue samples from MDs with ICRP, compared with findings for control tissue samples. A weak correlation was detected between serine protease activities and MMP-9 activity. CONCLUSIONS AND CLINICAL RELEVANCE: Study results suggested that gelatinase and serine protease activities are upregulated in the colorectal mucosa of MDs with ICRPs, possibly contributing to the pathogenesis of this disease through the functions of these enzymes in degradation of extracellular matrix and promotion of inflammatory cell migration and inflammatory responses.

Solvent-based paclitaxel or nab-paclitaxel for heavily treated relapsed/refractory small cell lung cancer: Retrospective single-institution observational study.

Treatment options for patients with relapsed/refractory small cell lung cancer (R/R SCLC) are limited, and the efficacy of salvage therapies for heavily treated patients should be assessed. Here, we evaluated the efficacy of paclitaxel (PTX) in R/R SCLC patients.A single-institute retrospective chart review was conducted. The primary endpoint was overall survival (OS), whereas the secondary endpoints were progression-free survival (PFS), overall response rate, disease control rate (DCR), and safety.Thirty-one patients (median age, 69 [range, 56-80] years) were analyzed. The median follow-up period was 122 (range, 28-1121) days. The median OS and PFS were 4.4 and 2.2 months, respectively. Adverse events of grade 3 or higher, other than hematological toxicity, were febrile neutropenia and neuropathy. Multivariate analyses identified the following independent predictors of poor OS: performance status and lactate dehydrogenase at the upper limit of normal.PTX monotherapy showed moderate efficacy with acceptable toxicity in heavily treated patients with R/R SCLC patients.

Design of Environmentally Responsive Fluorescent Polymer Probes for Cellular Imaging.

We report the development of environmentally responsive fluorescent polymers. The reversible temperature-induced phase transition of copolymers composed of N-isopropylacrylamide and a fluorescent monomer based on the fluorescein (FL), coumarin (CO), rhodamine (RH), or dansyl (DA) skeleton was used as a molecular switch to control the fluorescence intensity. The poly(N-isopropylacrylamide) (PNIPAAm) chain showed an expanded coil conformation below the lower critical solution temperature (LCST) due to hydration, but it changed to a globular form above the LCST due to dehydration. Through the combination of a polarity-sensitive fluorophore with PNIPAAm, the synthetic fluorescent polymer displayed a response to external temperature, with the fluorescence strength dramatically changing close to the LCST. Additionally, the P(NIPAAm-co-FL) and P(NIPAAm-co-CO) polymers, containing fluorescein and coumarin groups, respectively, exhibited pH responsiveness. The environmental responsiveness of the reported polymers is derived directly from the PNIPAAm and fluorophore structures, thus allowing for the cellular uptake of the fluorescence copolymer by RAW264.7 cells to be temperature-controlled. Cellular uptake was suppressed below the LCST but enhanced above the LCST. Furthermore, the cellular uptake of both P(NIPAAm-co-CO) and P(NIPAAm-co-RH) conjugated with a fusogenic lipid, namely, l-α-phosphatidylethanolamine, dioleoyl (DOPE), was enhanced. Such lipid-conjugated fluorescence probes are expected to be useful as physiological indicators for intracellular imaging.

Identification of A2059G 23S rRNA and G439A rplC gene mutations in Streptococcus criceti strain OMZ 61, a strain resistant to azithromycin, josamycin and clindamycin.

Streptococcus criceti is a cariogenic organism that belongs to the mutans streptococci. Of the four S. criceti strains, strain OMZ 61 has been identified as being resistant to erythromycin. Antimicrobial susceptibility testing showed that strain OMZ 61 is also resistant to azithromycin, josamycin and clindamycin but susceptible to tetracycline and tiamulin. DNA hybridization analysis of the 23S rRNA genes revealed that the hybridization patterns in strain OMZ 61 differed from those in the other three strains. We further analyzed the nucleotide sequences of a ribosomal RNA operon, the rrnD operon, and the rpsJ-rpsQ region including rplC and rplD genes for ribosomal proteins L3 and L4, respectively, in the four strains studied. Nucleotide sequence analysis indicated that strain OMZ 61 contains an A-to-G substitution at nucleotide position 2059, equivalent to Escherichia coli numbering 2058, in a 23S rRNA gene (rrlD) and a G-to-A substitution at nucleotide position 439 in the rplC gene, suggesting an amino acid residue change at position 147 from valine to isoleucine, whereas no mutation in the rplD gene was found. DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism analysis showed that most or all of the 23S rRNA genes in strain OMZ 61 contain the A2059G mutation. These findings suggest that the resistance to erythromycin, azithromycin, josamycin and clindamycin in strain OMZ 61 is conferred by alterations in 23S rRNA and/or ribosomal protein L3. This is the first description of mutations in the 23S rRNA and rplC genes in mutans streptococci.

Molecular characterization of the dextran-binding lectin B gene dblB of Streptococcus criceti in Streptococcus mutans strain GS-5 with mutations in both gbpC and spaP genes.

Streptococcus mutans, a cariogenic agent, has a glucan-binding protein gene, gbpC, and S. criceti possesses four gbpC homologs, including dblA and dblB, as does S. sobrinus. The S. criceti dblB gene encodes a 1,717-amino-acid protein having two repetitive alanine-rich and proline-rich regions and an LPXTG motif, which is recognized by the sortase SrtA, near the C terminus. Reverse transcription-PCR analysis indicated no cotranscription of the dblA and dblB genes of S. criceti. As we could not obtain a dblB mutant of S. criceti, the dblB gene was characterized in S. mutans strain GS-5, which has genetic mutations in both gbpC and spaP genes and shows an inability to agglutinate triggered by dextran. A dextran-induced agglutination assay showed that S. mutans cells carrying dblB agglutinated in the presence of dextran. A hydrophobicity assay showed that the cells containing dblB were hydrophobic. A biofilm formation assay showed that the dblB gene was associated with biofilm formation by cells cultivated in brain heart infusion broth supplemented with glucose and maltose, but not sucrose. Nucleotide sequence analysis of the S. criceti strains studied revealed a frameshift mutation in the srtA gene encoding sortase, but intact dblA and dblB genes were found in dextran-induced agglutination-negative strains, whereas intact dblA, dblB and srtA genes were found in dextran-induced agglutination-positive strains. These results suggest the cell-surface localization of dblA and dblB gene products by SrtA and the responsibility of dblB for dextran-induced agglutination, cell-surface hydrophobicity and biofilm formation in S. criceti.

Removal of phenol from saline water by polyamine chelating resin.

Removal of phenol from saline water was carried out with chelating resin. A polyamine chelating resin, Diaion CR-20, removed phenol compounds selectively from industrial wastewater containing 2% salt. From saline water containing 20 mg/L phenol, 70% of the phenol was removed. After treatment, phenol was eluted from the resin by aqueous NaOH, and the resin could also be regenerated by heating in air. Diaion CR-20 adsorbed phenol even in the presence of FeCl3, indicating that treatment with this resin of wastewater containing metal can remove phenol and metal cations in a single step.

Identification and characterization of an autolysin gene, atlA, from Streptococcus criceti.

AtlA of Streptococcus mutans is a major autolysin and belongs to glycoside hydrolase family 25 with cellosyl of Streptomyces coelicolor. The autolysin gene (atlA) encoding AtlA was identified from S. criceti. AtlA of S. criceti comprises the signal sequence in the N-terminus, the putative cell-wall-binding domain in the middle, and the catalytic domain in the C-terminus. Homology modeling analysis of the catalytic domain of AtlA showed the resemblance of the spatial arrangement of five amino acids around the predicted catalytic cavity to that of cellosyl. Recombinant AtlA and its four point mutants, D655A, D747A, W831A, and D849A, were evaluated on zymogram of S. criceti cells. Lytic activity was destroyed in the mutants D655A and D747A and diminished in the mutants W831A and D849A. These results suggest that Asp655 and Asp747 residues are critical for lytic activity and Trp831 and Asp849 residues are also associated with enzymatic activity.