1.Clinical Relevance of Time-to-positivity in BACTEC9240 Blood Culture System.
Sang Hyuk PARK ; Hyoeun SHIM ; Nam Seop YOON ; Mi Na KIM
The Korean Journal of Laboratory Medicine 2010;30(3):276-283
BACKGROUND: Continuous monitoring systems have allowed determination of the time-to-positivity (TTP). We evaluated the clinical relevance of TTP in the BACTEC9240 system (Becton-Dickinson, USA). METHODS: A total of 2,354 vials of positive blood cultures were evaluated over 2 months. TTP was monitored from each of BACTEC Plus Aerobic/F (BD) or Pediatric Plus/F and Lytic Anaerobic/F bottles, and the differential time-to-positivity (DTP) for blood samples drawn simultaneously via catheter and a peripheral site was determined. RESULTS: The average TTP of the positive vials was 17.4 hr, and 79.9% and 95.2% of the vials showed positivity within 24 and 48 hr, respectively. While the average TTP values for Aeromonas hydrophila, Bacillus cereus, Acinetobacter baumannii, and Streptococcus pneumoniae were less than 10 hr, those for Candida spp., anaerobes, Propionibacterium acnes, Corynebacterium spp, Bacillus spp. other than cereus, and coagulase-negative staphylococci were 35.3, 27.0, 56.8, 45.8, 23.0, and 26.3 hr, respectively. The negative predictive values of TTP over 24 hr to predict Staphylococcus aureus among staphylococci and S. pneumoniae among alpha-hemolytic streptococci were 76.7% and 100%, respectively. Enterobacteriaceae and Enterococcus faecalis showed shorter TTP in anaerobic vials than in aerobic vials. DTP of more than 2 hr was observed for 27.8%, 72.2%, and 45.5% of S. aureus, S. epidermidis, and Candida spp. CONCLUSIONS: TTP can be used to discriminate pathogens and contaminants. The shorter TTP in anaerobic vials of certain Enterobacteriaceae and Enterococcus spp. would facilitate further identification. DTP is useful for diagnosing catheter-related bloodstream infection by S. aureus, S. epidermidis, and Candida spp.
Bacteremia/*diagnosis
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Bacteria, Aerobic/isolation &purification
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Bacteria, Anaerobic/isolation &purification
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Bacteriological Techniques/instrumentation/methods
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Humans
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Reagent Kits, Diagnostic
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Time Factors
3.Comprehensive Analysis of Blood Culture Performed at Nine University Hospitals in Korea.
Jeong Hwan SHIN ; Sae Am SONG ; Mi Na KIM ; Nam Yong LEE ; Eui Chong KIM ; Sunjoo KIM ; Sun Hoi KOO ; Nam Hee RYOO ; Jae Seok KIM ; Ji Hyun CHO
The Korean Journal of Laboratory Medicine 2011;31(2):101-106
BACKGROUND: Optimal blood culture performance is critical for successful diagnosis and treatment of sepsis. To understand the status of blood culture, we investigated several aspects of the procedure at 9 university hospitals. METHODS: The process of ordering blood culture sets and sampling volume for adults and children was investigated from January 2010 to April 2010, while the positive rate of detection and growth of skin contaminants were compared in 2009. Microbial growth in aerobic and anaerobic bottles was investigated prospectively. RESULTS: A majority of the hospitals used 2 sets of bottles for adults and 1 bottle for children. The average blood volume in each set was 7.7 mL for adults and 2.1 mL for children. The positive rate of microorganisms was 8.0%, and the isolation rate of the normal flora of the skin was 2.1%. Bacterial growth rates in aerobic and anaerobic bottles only were 31.8% and 24.5% respectively. CONCLUSIONS: Ordering blood culture sets and sampling volumes did not comply with CLSI guidelines. However, the rate of positive cultures and skin contamination rates were acceptable. Anaerobic bottles are useful in enhancing the yield of microorganisms.
Adult
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Bacteremia/blood/*microbiology
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Bacteria, Aerobic/isolation & purification
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Bacteria, Anaerobic/isolation & purification
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Blood/microbiology
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Child
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Hospitals, University
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Humans
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Prospective Studies
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Republic of Korea
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Skin/microbiology
4.Infected Pneumatocele Following Anaerobic Pneumonia in Adult.
Sang Hyun KIM ; Yeon Tae CHUNG ; Kyung Duk LEE ; Kyoung Youn SEON ; Jong Hyun LEE ; Sung Ho LEE ; Se Ho CHOI
The Korean Journal of Internal Medicine 2005;20(4):343-345
We report a case of an infected pneumatocele in the course of anaerobic pneumonia in an adult. To the best of our knowledge, anaerobic pneumonia complicated by a pneumatocele in an adult has not previously been described. The pneumatocele occurred on the fifth day of hospitalization, and rapidly increased in size, with the development of a subsequent mixed anaerobe infection. A pig-tail catheter was inserted and the pus drained. The bacterial culture from the pus was positive for three anaerobes: Bacteroid species, Peptostreptococcus asaccharolyticus and Fusobacterium species. Intravenous antibiotics and percutaneous catheter drainage resulted in a successful treatment.
Pneumonia, Bacterial/*complications/microbiology
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Pneumocephalus/*complications/microbiology
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Middle Aged
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Male
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Humans
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Gram-Negative Anaerobic Bacteria/isolation & purification
5.Effect of sequential biocatalyst addition on Anammox process.
Chongjian TANG ; Ping ZHENG ; Jianwei CHEN
Chinese Journal of Biotechnology 2011;27(1):1-8
Anaerobic ammonium oxidation (Anammox) process is a high-rate nitrogen removal technology that has been applied in sludge dewatering effluents treatment with nitrogen removal rate as high as 9.5 kg/(m x d). However, due to the slow growth rate of the autotrophic Anammox bacteria and the susceptivity to environmental conditions, the start-up of Anammox process is very long; the operation is unstable; and the nitrogen removal from organic-containing and/or toxicant-containing ammonium-rich wastewaters using Anammox process becomes difficult. Thus, the application of this high-rate process is significantly limited. In this paper, a newly-developed Anammox process with sequential biocatalyst (Anammox biomass) addition was established based on the procedure in fermentation engineering. We introduced the Anammox process with sequential biocatalyst addition on start-up, stable operation and the treatment of organic-containing and toxicant-containing ammonium-rich wastewaters. Results show that supplementing high-activity Anammox biomass into reactors will increase the amount of as well as the ratio of Anammox bacteria. Thus, the innovative Anammox process with sequential biocatalyst addition not only accelerates the start-up course, but also enhances the stability of Anammox process. Furthermore, it overcomes the drawbacks of wastewaters containing high organic content and toxic substances. Therefore, the application of Anammox process may be further enlarged.
Bacteria, Anaerobic
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enzymology
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growth & development
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metabolism
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Biocatalysis
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Biomass
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Bioreactors
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microbiology
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Enzymes
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chemistry
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Nitrogen
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isolation & purification
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metabolism
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Oxidation-Reduction
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Quaternary Ammonium Compounds
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isolation & purification
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metabolism
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Waste Disposal, Fluid
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methods
6.Oral microflora of 42 patients with oral squamous cell carcinoma.
Xiao LU ; Ning GAO ; Changmei WANG ; Xiaorong XIAO
West China Journal of Stomatology 2002;20(5):356-360
OBJECTIVEThe purpose of this study was to evaluate the effects of squamous cell carcinoma on oral bacteria.
METHODSThis study investigated the microbial contents of the plaque on the surfaces of oral squamous cell carcinomas. Samples were obtained from the central surface of lesions, contiguous healthy mucosa and saliva of 42 patients with oral squamous carcinoma before and after operation.
RESULTSThe median of bacterial colony forming units per milliliter (CFUs/ml) of saliva before operation was 8.10 x 10(8) CFUs/ml. The median of CFUs per square centimeter of the tumor surface was 5.21 x 10(5) CFUs/cm2 which was significantly higher than that of the healthy (the control) mucosa (1.77 x 10(4) CFUs/cm2, P = 0.0001). The CFUs per square centimeter of mucosa surface at the operative zone was 4.34 x 10(5) CFUs/cm2 which was also significantly higher than that of the healthy (control) mucosa(7.24 x 10(4) CFUs/cm2, P = 0.0001).
CONCLUSIONOral carcinoma can break the balance of oral microflora, which may be one of the reasons leading to the high susceptivity of these compromised patients to systemic infection.
Adult ; Aged ; Bacteria, Aerobic ; isolation & purification ; Bacteria, Anaerobic ; isolation & purification ; Bacterial Infections ; etiology ; prevention & control ; Carcinoma, Squamous Cell ; microbiology ; Female ; Humans ; Male ; Middle Aged ; Mouth Mucosa ; microbiology ; Mouth Neoplasms ; microbiology ; Saliva ; microbiology ; Streptococcal Infections ; prevention & control ; Streptococcus ; isolation & purification
8.Study on anaerobic treatment of wastewater containing hexavalent chromium.
Yan-bin XU ; Hua-hua XIAO ; Shui-yu SUN
Journal of Zhejiang University. Science. B 2005;6(6):574-579
A self-made anaerobic bio-filter bed which was inoculated with special sludge showed high efficiency in removing hexavalent chromium. When pump flow was 47 ml/min and COD(Cr) of wastewater was about 140 mg/L, it took 4 h to decrease the Cr6+ concentrations from about 60 mg/L to under 0.5 mg/L, compared with 14 h without carbon source addition. Cr6+ concentrations ranged from 64.66 mg/L to 75.53 mg/L, the system efficiency was excellent. When Cr6+ concentration reached 95.47 mg/L, the treatment time was prolonged to 7.5 h. Compared with the contrast system, the system with trace metals showed clear superiority in that the Cr6+ removal rate increased by 21.26%. Some analyses also showed that hexavalent chromium could probably be bio-reduced to trivalent chromium, and that as a result, the chrome hydroxide sediment was formed on the surface of microorganisms.
Bacteria, Anaerobic
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metabolism
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Biodegradation, Environmental
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Bioreactors
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microbiology
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Cell Culture Techniques
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methods
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Chromium
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isolation & purification
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pharmacokinetics
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Industrial Waste
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prevention & control
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Sewage
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microbiology
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Water Purification
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methods
9.Distribution of anaerobes in periodontal abscess and its resistance to antibiotics.
Jun-lin HE ; Li-ying YU ; Jia-zhen CHEN
Chinese Journal of Stomatology 2012;47(12):719-724
OBJECTIVETo isolate and culture the predominant anaerobes from the periodontal abscesses, and to test the antibiotic susceptibility and drug resistant genes of the strains.
METHODSThe isolated strains were identified by both API20A biochemical method and polymerase chain reaction (PCR) method. The antibiotic susceptibility test was performed by agar dilution method. The resistant genes of the drug-resistant strains obtained were screened by PCR.
RESULTSThe anaerobes were detected in 48% (28/58) of the samples and Prevotella melaninogenica (Pm) was mostly identified in 43% (12/28). API20A biochemical method had 82% (23/28) agreement with the 16SrRNA method in identification rate. Anaerobes were resistant to metronidazole, clindamycin and cefmetazole. The erythromycin-resistant methylase genes F (ermF) gene was detected in three of eight clindamycin resistant strains. None of them was found coded on bacterial plasmids. However, no metronidazole resistant gene was detected on drug resistant strains.
CONCLUSIONSPm was the predominant species dectected in the periodontal abscess of the patients. The antibiotic agents should be used based on the genotypes and general condition of the patients.
Adult ; Anti-Bacterial Agents ; pharmacology ; Bacteria, Anaerobic ; isolation & purification ; Cefmetazole ; pharmacology ; Clindamycin ; pharmacology ; Drug Resistance, Bacterial ; genetics ; Erythromycin ; pharmacology ; Female ; Genes, Bacterial ; Humans ; Male ; Metronidazole ; pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Periodontal Abscess ; microbiology ; Prevotella ; isolation & purification
10.Evaluation of VITEK Mass Spectrometry (MS), a Matrix-Assisted Laser Desorption Ionization Time-of-Flight MS System for Identification of Anaerobic Bacteria.
Wonmok LEE ; Myungsook KIM ; Dongeun YONG ; Seok Hoon JEONG ; Kyungwon LEE ; Yunsop CHONG
Annals of Laboratory Medicine 2015;35(1):69-75
BACKGROUND: By conventional methods, the identification of anaerobic bacteria is more time consuming and requires more expertise than the identification of aerobic bacteria. Although the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems are relatively less studied, they have been reported to be a promising method for the identification of anaerobes. We evaluated the performance of the VITEK MS in vitro diagnostic (IVD; 1.1 database; bioMerieux, France) in the identification of anaerobes. METHODS: We used 274 anaerobic bacteria isolated from various clinical specimens. The results for the identification of the bacteria by VITEK MS were compared to those obtained by phenotypic methods and 16S rRNA gene sequencing. RESULTS: Among the 249 isolates included in the IVD database, the VITEK MS correctly identified 209 (83.9%) isolates to the species level and an additional 18 (7.2%) at the genus level. In particular, the VITEK MS correctly identified clinically relevant and frequently isolated anaerobic bacteria to the species level. The remaining 22 isolates (8.8%) were either not identified or misidentified. The VITEK MS could not identify the 25 isolates absent from the IVD database to the species level. CONCLUSIONS: The VITEK MS showed reliable identifications for clinically relevant anaerobic bacteria.
Bacteria, Anaerobic/*genetics/isolation & purification
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Bacterial Typing Techniques/*instrumentation/*methods
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Body Fluids/microbiology
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Databases, Genetic
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Humans
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RNA, Ribosomal, 16S/*analysis/metabolism
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Sequence Analysis, DNA
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*Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization