Mycobacterium angelicum sp. nov., a non-chromogenic, slow-growing species isolated from fish and related to Mycobacterium szulgai.

The name 'Mycobacterium angelicum' dates back to 2003 when it was suggested for a slowly growing mycobacterium isolated from freshwater angelfish. This name is revived here and the novel species is proposed on the basis of the polyphasic characterization of four strains including the original one. The four strains presented 100 % 16S rRNA gene sequence similarity with Mycobacterium szulgai but clearly differed from M. szulgai for the milky white aspect of the colonies. The sequence similarity with the type strain of M. szulgai ranged, in eight additionally investigated genetic targets, from 78.9 to 94.3 %, an evident contrast with the close relatedness that emerged at the level of 16S rRNA gene. The average nucleotide identity between the genomes of M. szulgai DSM 44166T and strain 126/5/03T (type strain of the novel species) was 92.92 %, and supported the status of independent species. The confirmation of the name Mycobacterium angelicum sp. nov. is proposed, with strain 126/5/03T ( = CIP 109313T = DSM 45057T) as the type strain.

Genetic characteristics of CTX-M-type extended-spectrum-ß-lactamase (ESBL)-producing enterobacteriaceae involved in mastitis cases on Japanese dairy farms, 2007 to 2011.

Sixty-five CTX-M-2/15/14 extended-spectrum-ß-lactamase-producing Enterobacteriaceae were isolated from 258,888 mastitic milk samples from Japanese dairy farms between 2007 and 2011. CTX-M-2-producing Klebsiella pneumoniae and CTX-M-15-producing Escherichia coli were the predominant strains isolated. There was no predominant clonal type, and clonal diversity was found even in strains isolated from a single farm.

Evaluation in vitro of the efficacy of colistin methanesulfonate against biofilm-forming multidrug-resistant Pseudomonas aeruginosa (MDRP).

The aim of this study was to evaluate in vitro the efficacy of clinically using colistin methanesulfonate against biofilm-forming multidrug-resistant Pseudomonas aeruginosa (MDRP), with minimum inhibitory concentrations (MICs) of ciprofloxacin, imipenem, and amikacin showing ≥4, 16, and 32 µg/ml, respectively, by disk diffusion susceptibility testing (CLSI document M100-S21). The minimum eradication biofilm concentration (MBEC) of colistin methanesulfonate for strain MDRP-YMD isolated from a patient's urine, which formed a biofilm on plastic pegs attached to a microplate lid, was compared with that of P. aeruginosa ATCC27853 for quality control testing with MICs of ciprofloxacin, imipenem, and amikacin showing ≤1, 4, and 16 µg/ml, respectively. In an uneven biofilm approximately 10 µm thick, as determined with confocal laser scanning microscopy (CLSM), ratios of MBEC to MIC of colistin methanesulfonate against strains MDRP-YMD and ATCC27853 were 10.5 and 8.0, whereas those of minimum bactericidal concentration (MBC) to MIC in planktonic cells were 1.0 and 2.0 µg/ml, respectively. Morphological examination using scanning electron microscopy and CLSM verified that embedded cells in biofilm matrices of the two strains were disrupted and died under the MBEC. Therefore, bactericidal effects of colistin methanesulfonate on biofilm-forming cells of strain MDRP-YMD as well as strain ATCC27853 were significantly decreased compared with those on the planktonic cells.

[Annual incidence of human group A rotavirus G-serotypes detected in a Japanese University Hospital between 2003 and 2007].

Group A rotavirus G-serotyping by polymerase chain reaction (PCR) using university hospital subject samples in September 2003 to August 2004, September 2004 to August 2005, September 2005 to August 2006, and September 2006 to August 2007 showed the most common serotypes G1 and G3, detected in 27 and 33 subjects, compared to 4 subjects in whom serotype G4 was detected. Between 2003 and 2004, serotypes G1 accounted for 50% and G3 for 38%, contrasting with serotype G3 at 79% between 2004 and 2005, serotype G1 at 91% between 2005 and 2006, and serotype G1 and G3 at 37% and 63% between 2006 and 2007, respectively. Serotypes G2 and G9 were not detected at all during any of our time periods. No correlation was seen between subject age and G serotype, although subjects younger than two years old accounted for 73% of subjects. This infection caused combined fever, diarrhea, and vomiting in 48% of subjects but showed no correlation with G serotype. These findings under-score the importance of G-serotyping in understanding rotavirus infection epidemiology at different times and in different locales.

[Mycobacterium fortuitum infection caused by the organism in subcutaneous abscess mediated by central venous catheter].

A 49-year-old woman with a Mycobacterium fortuitum bloodstream infection, who has been managed with central venous (CV) catheterization for two years, was reported. She had undergone rectectomy for rectal cancer and gastectomy for stomach cancer at the ages of 36 and 42, respectively. Also, she had undergone adhesiotomy for four times for postoperative ileus at the ages between 44 and 47. She was admitted to our hospital because of fever (38.4 degrees C) with chill and fatigue, and a subcutaneous abscess at the right infraclavicular region located at the insertion site of the CV catheter (Hickman catheter). After the catheter was removed, the subcutaneous abscess was incised and a Penrose drain tube was inserted. M. fortuitum was detected after three days of blood culture and on the blood agar medium inoculated with purulent discharge from the drainage tube. After receiving these treatments, she was discharged from the hospital one month later. The isolates from these blood and purulent discharge specimens were identical on pulsed-field gel electrophoresis. Based on these findings, we concluded that the M. fortuitum bloodstream infection in this case might be caused by the organism in the subcutaneous abscess mediated by the CV catheter.

[Isolation of Serratia marcescens from patient specimens in one Japanese hospital between April 2002 and March 2004].

In this study, the isolation frequency, 131 isolates including seven duplicates from the same patient, of Serratia marcescens from patient specimens obtained at Showa University Fujigaoka Hospital between April 2002 and March 2004 was investigated in comparison with 156 isolates including 8 duplicates, obtained between April 1999 and March 2002. The isolation percentage of 40%, 53 isolates from respiratory specimens in the recent period was the same with that of 40%, 62 isolates in the previous period, while that percentage of 12%, 16 isolates from urine specimens, was significantly smaller than the previous percentage of 24%, 37 isolates p < 0.01, X2-test). Furthermore, the isolation percentage of 41%, 20 of 49 isolates with serotype 02 from respiratory specimens, in the recent period did not significantly differ from that of 43%, 18 of 42 isolates, in the previous period. However, the isolation percentage of 24%, 9 of 37 isolates with serotype 014 from urine specimens, in the recent period was significantly smaller than that of 67%, 20 of 30 isolates, in previous period (p < 0.001, chi squared-test). The decrease in this period resulted from having avoided unnecessary monitoring for urinary tract infection without diagnostic value. The isolation percentage of 12%, 16 isolates from blood specimens, in this period was significantly greater than that of 3%, 4 isolates, in the previous period (p < 0.001, chi squared-test). By pulsed-field gel electrophoresis (PFGE) analysis of Spe I-restricted chromosomal DNA, clones from 5 of 6 isolates from blood specimens were identical to the isolate from another specimen (sputum, catheter-derived urine, indwelling catheter, used IVH catheter tip, or used drainage tube), while the one remaining isolate were a neighbor clone to the isolate from aspirated sputum. Such incidents seemed to have been caused by serratial cross-contamination in the hospital, reflecting inadequate practice of standard precautions.

[Two nosocomial outbreaks of sepsis caused by Serratia marcescens, which occurred in July 1999 and January 2002--Tokyo].

Two nosocomial outbreaks of sepsis caused by Serratia marcescens, which occurred in Tokyo were the following cases. CASE A: In July 1999, 10 inpatients admitted to the third floor ward of the General Hospital A, developed sudden onset of high fever, coagulation disorders (disseminated intravascular coagulation), and acute renal failure, of which 5 died. Twenty-one strains of Serratia marcescens were isolated from the inpatient's blood and urine, nurse fingers and environmental samples from floor and cooling tower. Serratia infection was strongly suspected as the cause of sepsis. These cases were defined as "inpatients who developed fever 38 degrees C or more during July 26 to 29 and from whom S. marcescens was isolated by blood culture". Ten isolates were detected from the blood. In order to investigate the background of S. marcescens isolation in the hospital and to compare molecular and biochemical characteristics of S. marcescens, cultures were attempted from samples of other inpatients and staffs and hospital environment. Those were classified into 9 groups by various different typings: biotyping with Api Rapid 20; susceptibility typing of antimicrobial agents tested; pulsed-field gel electrophoresis (PFGE) typing of SpeI- or Xba I-restricted chromosome. All 10 isolates causing sepsis were found to be in the same group. CASE B: In January 2002, 24 inpatients, admitted to Neurosurgical Hospital B, developed sudden onset of high fever, of which 7 died. S. marcescens was isolated from a towel, environmental samples and inpatients. These cases were defined as "inpatients who developed fever of 38.5 degrees C and S. marcescens isolated by blood culture". Twelve strains were isolated from the blood samples in 12 cases. In order to investigate the background of S. marcescens isolation in the hospital, cultures were attempted from other inpatient's urine and environmental samples from medical tape, Tshake and a towel. These isolates were classified into 3 groups by the previous typings; biotyping with Api Rapid 20; susceptibility typing of antimicrobial agents tested; and PFGE typing. All 12 isolates in 12 cases were found to be in the same group. These cases of 2 nosocomial outbreaks of sepsis were defined as "in-patient who developed high fever and S. marcescens isolated by blood culture". However in both cases transmission routes of Serratia infection remain unknown by field investigation.

[Molecular-epidemiological evaluation of Serratia marcescens isolates from patient specimens in one Japanese hospital during the three years from April 1999 to March 2002].

One hundred fifty-six isolates of Serratia marcescens from patient specimens in Showa University Fujigaoka Hospital between April 1999 and March 2002 were investigated in this study. Forty-two isolates with serotype O2, detected mainly from patient respiratory specimens, were susceptible to the antimicrobial agents tested, whereas 30 isolates with serotype O14, detected mainly from patient urine, were resistant. Moreover, 19 isolates with serotype O14 susceptible to imipenem were intermediate or resistant to meropenem, while they did not produce metallo beta-lactamase. Both serotypes were significantly distributed in the ICU and surgical wards, compared with other wards. Ten isolates with O2/B (bacteriocin type) 16 and 14 isolates with O14/B76J, showing identical or closely-related clones by pulsed-field gel electrophoresis (PFGE) analysis of Spe I-restricted chromosome, were detected from different inpatients' specimens during approximately 2 and a half years. The existence of such long-lasting microorganisms suggested the possibility of hospital-acquired infection caused by inadequate use of antimicrobial agents and disinfection procedures for medical tools such as bite blocks and catheters.

Effect of linezolid against postneurosurgical meningitis caused by methicillin-resistant Staphylococcus epidermidis: case report.

A 67-year-old man who had twice previously undergone operations for a tuberculum sellae meningioma was admitted to hospital for further treatment. After the third surgical intervention, the patient developed persistent low-grade fever and impaired consciousness. Computed tomography, 1 week after surgery, showed postsurgical hydrocephalus. Cerebrospinal fluid (CSF) studies revealed high intracranial pressure (above 30 cm H2O), and increased cell count (1232/3). One week after the ventricular drainage, coagulase-negative Staphylococcus epidermidis was recovered from his CSF, and antimicrobial susceptibility results indicated that the organism was methicillin-resistant. After 14 days of intravenous vancomycin (VCM) administration failed, linezolid (LZD) was initialized intravenously, resulting in a resolution of the meningitis. After a ventriculoperitoneal shunt procedure was performed, LZD was continued orally, which resulted in a cure. CSF penetration by VCM is reported to be poor, i.e., approximately 10% of serum concentration, which may explain its lack of efficacy. In this case, the penetration of LZD into the CSF was 58.9% of the peak value and 133% of the trough value of serum concentrations. LZD must be considered one of the first-line treatments against surgical-site infection in neurosurgery caused by methicillin-resistant Staphylococci.

Isolation rate of non-hemagglutinating strains of Serratia marcescens from clinical specimens in a general hospital: comparison of serotypes O2 and O14.

Given the absence of recent reports on the isolation rate of Serratia marcescens by pili type, clinical isolates from respiratory and urinary tract specimens--prime loci of infection by this organism--were subjected to examination. The 123 S. marcescens strains (serotype O2, 67 strains, serotype O14, 56 strains) used in this study were isolated from inpatients at Showa University Fujigaoka Hospital during the 5 years from April 1997 to March 2002. Higher rates of S. marcescens O2 with mannose-resistant (MR)/K Klebsiella-like pili were detected among the respiratory tract-derived strains. On the other hand, more non-hemagglutinating O14 strains were found among the urinary tract-derived strains. Analysis by study phase revealed a rise in the isolation rate of non-hemagglutinating strains, from 0-17.4% for O2 strains and 34.5%-66.7% for O14 strains, between phase I (April 1997 to March 1999) and phase II (April 1999 to March 2002) of the study. In order to examine the increasing non-hemagglutinating strains in detail, the 28 serotype O14 non-hemagglutinating strains, and 8 strains with only mannose-sensitive (MS) pili were subjected to genotyping by pulsed-field gel electrophoresis (PFGE), revealing the presence of 10 clones with disparate genotypes. The A1 strain isolated at the highest frequency was non-hemagglutinating in all cases and possessed the same genotype, indicating proliferation within the hospital over the 5 years of the study. These results indicate that non-hemagglutinating strains were transmitted among patients within the hospital.

Experimental confirmation of Serratia marcescens contamination in multiple-dose vials of heparin-saline solution.

The initial contamination of heparin-saline solution (HS) in multiple-dose vials (MDVs) by Serratia marcescens was experimentally investigated using various isolates. Isolates I2 and S1 were from blood specimens from patients with a hospital-acquired infection (HAI). Isolates I13 and FHSM9043 were from urine and blood specimens, respectively, from patients without HAI. Isolate I124, with a pulsed-field get electrophoresis pattern identical to that of isolate I2, was from the hospital environment. Viable cells of isolate I2 were carried over into the HS of MDVs when the contaminated rubber septum was pierced with a syringe needle. When the outside surface of the septum was contaminated by inoculating it with wet-cell suspensions in HS or Müller-Hinton broth, the viable cells carried over were detected at a minimum inoculum size (MIS) of 10(3) s cfu/ml. However, when the surface was contaminated by inoculating it with dry-cell suspensions, the viable cells carried over were detected at an MIS of 10(7) s cfu/ml. The viable cells in the internal lumen of the needle much more than those on its outside surface spread to the HS of MDVs. For exposures of 24 h and 72 h at 4 degrees C to HS with 1% benzyl alcohol as a preservative in MDVs, viable cells of all isolates tested were detected at MIS values of 1 s and 10 s cfu/ml, respectively, increases three orders of magnitude smaller than those of reference strain IFO3736. These results suggest that S. marcescens isolates are readily carried over into the HS of MDVs by piercing a wet, contaminated rubber septum with a syringe needle. Also, despite the sterilization action of 1% benzyl alcohol, the organism persistently survived at 4 degrees C, even when initial contamination was with a small amount of inoculum.