A minimal test scheme, consisting of deoxyribonuclease (DNase) and tween 80 hydrolysis (TEH) together with a few other biochemical tests, was used to make tentative identification of Serratia marcescens from clinical specimens. The identifications were reevaluated by testing comprehensive biochemical characteristics of 52 isolates, and all were found to be correct. The biochemical reactions of the isolates were very homogenous, showing typical characteristics of the species except in the urease test and acid production from sucrose, adonitol and inositol. These facts support the feasibility of the use of the minimal identification scheme. Pigment production was noted only in 7 isolates invalidating the value of this characteristic for the identification. Fifty-seven isolates were tested for their antibiotic susceptibility. They were found most frequently susceptible to gentamicin (47.4%), chloramphenicol (35.0%) and kanamycin (28.1%). Many isolates (49.1%) were multiply resistant to ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin and tetracycline.
Antibiotics/pharmacology* ; Cells, Cultured ; Drug Resistance, Microbial ; Human ; Microbial Sensitivity Tests ; Serratia marcescens/drug effects ; Serratia marcescens/isolation & purification ; Serratia marcescens/metabolism*

Serratia marcescens jn01 was employed as the host for the isolation of phages from environmental sewage. One strain of phage named SmPjn was purified by picking transparent plaque with 2mm diameter and clear edge on the double-layer agar repeatedly. Electron micrographs indicated that the phage head was icosahedral with head size and tail length of (58 +/- 2.16) x (55 +/- 0.47) nm and (7 +/- 1.25) nm, respectively. On the basis of the morphology, this phage belongs to the family Podoviridae. Host-range determination revealed that the phage was capable of infecting the other two isolates of S. marcescens, P25 and CMCC41002. The optimal multiplicity of infection was 1. A one-step growth curve of SmPjn indicated that the latent period and burst size were estimated at 50 min and 1,125 pfu/cell, respectively . Genomic DNA of SmPjn was above 27kb in size and could be digested by Hind Ill and EcoR I into 11 and 9 visible fragments after electrophoresis, respectively. A novel Podoviridae-phage infecting S. marcescens was firstly reported in China.
China ; DNA, Viral ; genetics ; isolation & purification ; metabolism ; Host Specificity ; Podoviridae ; genetics ; growth & development ; isolation & purification ; Restriction Mapping ; Serratia marcescens ; physiology

OBJECTIVETo establish a testing and evaluating method for filtration efficiency of the canister against microbial aerosol.

METHODSSerratia marcescens aerosol served as model of bacterial aerosol, Bacillus subtilis var niger aerosol as model of spores aerosol, bacteriophage f(2) aerosol as model of viral aerosol. Employing the microbial aerosol testing platform was established in lab, models of microbial aerosol generated artificially were sampled quantitatively by air samplers before and after filtrating by canisters, respectively. Filtration efficiency was determined by the concentration of microbial aerosol in the air sample before and after filtrating. The four canisters of 1-1, 1-2, 1-3, 1-4 were tested for the filtration efficiency against Serratia marcescens, Bacillus subtilis var niger and phage f(2) aerosol. The two canisters of 543 and 544 canisters equipped with active carbon were tested for the filtration efficiencies against Serratia marcescens aerosol.

RESULTSThe filtration efficiency of 1-1, 1-2, 1-3 canisters against Serratia marcescens, Bacillus subtilis var niger and phage f(2) aerosol was 100.000%. The filtration efficiency of 1-4 canister filtration efficiency against Bacillus subtilis var niger spores aerosol was 99.997% and efficiency of the other two aerosol was 100.000%. The filtration efficiency of the two canisters of 543 and 544 to those attached with active carbon against Serratia marcescens aerosol was 100.000%.

CONCLUSIONThe testing method might be used to evaluate the protective performance of the canister against microbiological aerosol. The effect of the canisters (including those equipped with active carbon) against microbiological aerosol should be reliable.

Aerosols ; Air Microbiology ; Bacillus subtilis ; isolation & purification ; Filtration ; methods ; Levivirus ; isolation & purification ; Respiratory Protective Devices ; standards ; Serratia marcescens ; isolation & purification ; Spores, Bacterial ; isolation & purification

OBJECTIVETo develop a new sampling medium for detecting of bioaerosols.

METHODSThe sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditions, preliminary applications were performed using AGI-10 and high volume sampler.

RESULTSThe average recovery rates were raised to 24.7%, 58.2%, 40.5%, 44.1%, 20.5%, and 15.4%, respectively in six consecutive experiments under static condition for 60 min at room temperature. Four kinds of sampling media were singled out after static experiments, which were referred to as "samplutions" PD1, PX2, TD1, and TX2, respectively. Under the active condition, the protective efficacy of PD1, PX2, TD1, and TX2 was 226% (153/47), 553% (111/17), 150% (120/48), and 268% (419/114), respectively.

CONCLUSIONThe samplutions have some effects on the subsequent nucleic acid detection, which could be avoided by employing standard nucleic acid extraction procedure. The newly developed samplution can be applied to the detection of bioaerosols.

Aerosols ; analysis ; Air Microbiology ; Air Pollutants ; analysis ; Environmental Monitoring ; methods ; Escherichia coli ; isolation & purification ; Nucleic Acids ; isolation & purification ; Sampling Studies ; Serratia marcescens ; isolation & purification ; Staphylococcus aureus ; isolation & purification

No abstract available.
Aged ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; Drug Resistance, Bacterial/*genetics ; Fluoroquinolones/*pharmacology ; Humans ; Male ; Microbial Sensitivity Tests ; Mutation ; Serratia Infections/*diagnosis/microbiology ; Serratia marcescens/*drug effects/genetics/isolation & purification

No abstract available.
Aged, 80 and over ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics ; China ; Drug Resistance, Multiple, Bacterial ; Humans ; Male ; Methyltransferases/*genetics ; Microbial Sensitivity Tests ; RNA, Ribosomal, 16S/genetics/metabolism ; Serratia marcescens/drug effects/*enzymology/*genetics/isolation & purification ; Urinary Tract Infections/diagnosis/microbiology

To efficiently produce non-specific nuclease (NU) of Serratia marcescens through recombinant overexpression approach and to characterize the purified NU. The nuclease gene was amplified from the genomic DNA of Serratia marcescens by PCR and fused into vector pMAL-c4X with maltose binding protein (MBP) tag. The recombinant vector verified by DNA sequencing was transformed into Escherichia coli BL21. The expressed MBP-NU was purified through the amylose resin and its catalytic characters were analyzed. The results showed the NU gene had 97% identities with the reported S. marcescens nuclease gene and intracellularly expressed in E. coli BL21. The optimal expression conditions were 37 degrees C, 0.75 mmol/L IPTG with 1.5 h induction. The purified MBP-NU exhibited non-specific nuclease activity, able to degrade various nucleic acids, including RNA, single-stranded DNA and double-stranded DNA that was circular or linear. Its optimal temperature was 37 degrees C and optimal pH 8.0. From 1 L culture broth 10.8 mg NU could be purified with a specific activity of 1.11x10(6) U/mg. The catalytic activity of NU was not inhibited by reagents such as EDTA (0.5 mmol/L), PMSF (1 mmol/L) and KCl (150 mmol/L) commonly used in protein purification.
Base Sequence ; Endodeoxyribonucleases ; biosynthesis ; genetics ; Endoribonucleases ; biosynthesis ; genetics ; Escherichia coli ; genetics ; metabolism ; Maltose-Binding Proteins ; genetics ; Molecular Sequence Data ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification ; Serratia marcescens ; enzymology

PURPOSE: Over the last 30 years, Serratia marcescens (S. marcescens) has emerged as an important pathogen, and a common cause of nosocomial infections. The aim of this study was to identify risk factors associated with mortality in patients with S. marcescens bacteremia. MATERIALS AND METHODS: We performed a retrospective cohort study of 98 patients who had one or more blood cultures positive for S. marcescens between January 2006 and December 2012 in a tertiary care hospital in Seoul, South Korea. Multiple risk factors were compared with association with 28-day all-cause mortality. RESULTS: The 28-day mortality was 22.4% (22/98 episodes). In a univariate analysis, the onset of bacteremia during the intensive care unit stay (p=0.020), serum albumin level (p=0.011), serum C-reactive protein level (p=0.041), presence of indwelling urinary catheter (p=0.023), and Sequential Oran Failure Assessment (SOFA) score at the onset of bacteremia (p<0.001) were significantly different between patients in the fatal and non-fatal groups. In a multivariate analysis, lower serum albumin level and an elevated SOFA score were independently associated with 28-day mortality [adjusted odds ratio (OR) 0.206, 95% confidential interval (CI) 0.044-0.960, p=0.040, and adjusted OR 1.474, 95% CI 1.200-1.810, p<0.001, respectively]. CONCLUSION: Lower serum albumin level and an elevated SOFA score were significantly associated with adverse outcomes in patients with S. marcescens bacteremia.
Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents/therapeutic use ; Bacteremia/drug therapy/microbiology/*mortality ; Cross Infection/mortality ; Female ; Humans ; Intensive Care Units ; Male ; Middle Aged ; Multiple Organ Failure ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Factors ; Serratia Infections/diagnosis/drug therapy/*mortality ; Serratia marcescens/drug effects/*isolation & purification ; Severity of Illness Index ; Survival Rate ; Time Factors ; Treatment Outcome

We report a case of corneal perforation with preseptal cellulitis in a patient with acute lymphocytic leukemia (ALL). A 17-yr-old female patient who was undergoing combination chemotherapy for ALL was referred due to upper lid swelling and pain in the right eye for 2 days. Visual acuity in the right eye was 20/20. Initial examination showed no abnormal findings, other than swelling of the right upper eyelid. Computed tomography showed a finding of preseptal cellulitis. Microbiologic study of bloody and purulent discharge revealed Serratia marcescens. Corneal melting and perforation with iris prolapse were detected in the right eye on the 16th day. Emergent tectonic keratoplasty was performed. Seven months after surgery, visual acuity in the right eye was 20/300, and the corneal graft was stable.
Adolescent ; Anti-Bacterial Agents/therapeutic use ; Cellulitis/*diagnosis/drug therapy/etiology/microbiology ; Corneal Perforation/*diagnosis/etiology/therapy ; Corneal Transplantation ; Drug Therapy, Combination ; Female ; Humans ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/complications/*drug therapy ; Serratia marcescens/isolation & purification ; Tomography, X-Ray Computed ; Visual Acuity