Rinsho Biseibutsu Jinsoku Shindan Kenkyukai shi = JARMAM : Journal of the Association for Rapid Method and Automation in Microbiology最新文献

We attempted to analyze any influences to %T>MIC achievement probability due to the difference of the MIC measurement concentration range of MEPM for 613 strains of Pseudomonas aeruginosa by the Monte Carlo simulation method. As for the analysis, we calculated the achievement probability of 30% and 50% for MEPM %T>MIC by the administration volume of MEPM: 250 mg, 500 mg, and 1,000 mg, the administration time: 0.5 h, and 3 h, the administration frequency: 2 times, and 3 times, and the renal excretion capability: Normal, Slight, Moderate, and High abnormal with the 3 types of MIC concentration measurement level 1) <=0.06~>=256 µg/ml: 13 levels, 2) <=0.5~>=32 µg/ml: 7 levels, and 3) <=1~>=16 µg/ml: 5 levels. As the result, we found the following findings; 1. In terms of the administration of normal renal excretion capability, 250 mg, in comparison with 500 mg and 1,000 mg, indicated the differential due to the difference of MIC measurement concentration range. 2. The administration volume of MEPM 500 mg which has been recommended shown the less differential of the achievement probability due to the difference of MIC measurement concentration range. As the renal excretion was shifted through Normal to Slight to Moderate to High abnormal, the differential of the achievement probability due to the difference of MIC measurement concentration range was gradually decreased. With these results, PK/PD analysis is possible for the 5 levels measurement concentration. It is significant that the facility using the automated microbiology analyzer can provide not only the MIC report, but also the information on the appropriate administration method for antibacterial drug by PK/PD analysis.

The Gram stain is an established method for bacterial identification, but the time needed to carry out this stain is 2-3 min. We attempted to shorten this time and stained a total of 70 clinical specimens isolated from using the Bartholomew & Mittwer (B&M) modified or Favor methods with a 3 s duration for washing and staining steps. Results were plotted and analyzed using a Hue Saturation Intensity (HSI) model. The range based on a plot of the two methods with the HSI model was presented as a reference interval. Our results indicated that 100% (35/35) of strains were Gram positive and 97.1% (34/35) were Gram negative for the quick B&M modified method. In the quick Favor method, 80.0% (28/35) were Gram positive and 68.6% (24/35) of strains were Gram negative. We propose that the quick B&M modified method is equivalent to the standard Gram staining method and is superior to the quick Favor method.

A diagnostic test for infection has been developed which uses the culture method but there still remains the issue of non-culturable pathogens. Although genetic testing has emerged as a solution to this problem, it is not yet widely used. There are various reasons for this which includes the gene amplification and analysis methods used as well as the users not being familiar with the selection criteria. In recent years, by using inexpensive instrumentation it has become possible to observe specimens using fluorescent staining and to easily identify the pathogens. Also equipment for gene and protein analysis has been developed that can analyze each level of gene transcription and translation in the expressed proteins. Today, due to the many developments in both analytical methods and instrumentation, major breakthroughs are being made in clinical microbiological testing. That is, first, to classify the infecting microorganism by fluorescent staining and then to identify the microorganism using DNA sequencing and mass spectrometry. In addition, the DNA sequencing and Melting curve analysis methods are used to test for antimicrobial resistance of infectious microorganisms. For non-culturable microbes and the growth response of microbes under stress conditions, the Phenotype-Microarray method is used. Therefore, once the weaknesses of each method are understood, it is possible to provide accurate and timely information to clinicians.

Some automated systems of the identification and susceptibility for microorganisms are used and prevail in hospital laboratories. One of the most serious problems is to perform accurate susceptibility testing for low-level resistant organisms, while antibiotic resistant microbes are increasing in medical fields. To evaluate automated machines for the susceptibility testing, several antibiotic resistant organisms were examined by plural technicians in some laboratories. Each strain of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycinintermediate S. aureus (VISA), extended-spectrum β-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae was tested by three automated systems of WalkAway, VITEK2/VITEK2 compact and Phoenix for susceptibility. The results for antibiotics generated by the systems were compared to those generated by reference methods according to CLSI guidelines. The results of WalkAway, VITEK2/VITEK2 compact, and Phoenix demonstrated 92%, 91%, and 96% of reproducibilities, 92%, 94%, and 91% of MIC agreements, 0.5%, 0.8%, and 0.3% of very major error (VME) and 0.3%, 1.4%, and 2.3% of major error (ME), respectively. All automated systems had a high reproducibility even under the performance of plural technicians, although the differences of VMEs and MEs were observed among the systems. From these data, the automated systems for antimicrobial susceptibility testing were more useful for the detection of antibiotic resistant organisms by understanding the characteristics of each system.

We have analyzed epidemiology of pandemic influenza (H1N1) 2009 in Aichi Medical University hospital. As a result, the characteristics of pandemic influenza (H1N1) 2009 was as follows. (1) The number of ordered rapid diagnostic test was 2.8 times compared with the seasonal influenza period. The number of ordered rapid diagnostic test of the seasonal influenza period had the peak in January to March. However, the peak in pandemic influenza (H1N1) 2009 was November. Also, the number of samples on the weekend had been more than that of the weekday. (2) Positive rate of each diagnostic kit did not have the difference between the seasonal influenza (31.3 ± 1.8%) and pandemic influenza (H1N1) 2009 (29.6%). (3) Age on most ordered samples were less than ten years old, and the number of samples in 11 to 20 years old was twice in comparison with the seasonal influenza. (4) Pandemic influenza (H1N1) 2009 in influenza A accounted for 96.9%. (5) Sensitivity and specificity of ESPLINE Influenza A&B-N (FUJIREBIO, Inc., Tokyo, Japan) to the pandemic influenza (H1N1) 2009 were 100% and 100%, respectively. Also, sensitivity and specificity of prorasuto Flu (Mitsubishi Chemical Medience Corporation, Tokyo, Japan) were 77.3%and 98.5%, respectively.

MicroScan Rapid plus Neg II Series and MicroScan Rapid plus Pos Series by Siemens Healthcare Diagnostics K.K. are the panels which enable to measure identification and antimicrobial susceptibility testing quickly and we have confirmed that it is useful for detecting drug resistance bacteria. As the identification result of comparing Rapid plus series with the current panel by using 143 strains of various drug resistance bacteria, Gram positive cocci was 87. 7%, glucose fermenter was 100% and glucose non-fermenter was 77.3 in Gram negative bacilli. On the evaluation of antimicrobial susceptibility testing, Rapid plus series, in comparison with the current panel, confirmed the lower tendency of MIC value on some drugs, but it basically presented the good concordance rate. In terms of the reporting time of antimicrobial agent, non-fermenter or MRCNS reported the result as needed after 8 hours and it took a little longer time for the report of antimicrobial agent. On the other hand, 80% or higher of antimicrobial agent on panel was reported for intestinal bacteria in 4.5 hours and for MRSA in 6.5 hours. It enabled to report the testing result on the same day. Due to the results above, Rapid plus series was highly valued on the usability, such as the early detection of drug resistance bacteria and the selection of therapeutic agents.

(1) Early diagnosis of adenovirus infection helps physicians to relieve anxiety of guardians as it enables them to provide appropriate information on natural course and prognosis of the infection. In addition, it reduces unnecessary antibiotic use, which is associated with the emergence of drug-resistant bacteria. (2) Diagnostic accuracy in adenovirus infection could be improved by selection of patient prior to antigen detection test based on detailed history, local epidemic situation and actively performed blood test. (3) Positive rate of adenovirus antigen detection depends on the day of illness when it is performed and sampling technique. Vigorous rubbing of pharynx and tonsil to an extent that nausea or vomiting is induced is a clue to the collection of appropriate samples. (4) Recently released rapid adenovirus antigen detection kits are considered to be more useful than their old versions because of better sensitivity and shorter examination time. However, their usefulness in early diagnosis is limited, as they sometimes produce false-negative results at very early stage or in patients lacking symptoms other than fever.

Procalcitonin (PCT) is a novel biomarker for diagnosis and severity evaluation of bacterial sepsis. PCT measurement methods provided by Wako Pure Chemical Industries, Ltd. include a fully automated chemiluminescent immunoassay system SphereLight Wako and fully automated immunoanalyzer microTASWako i30 for a quantitative measurement, and immunochromatographic assay method, B R A H M S PCT-Q kit. This time, basic performance of SphereLight Wako and microTASWako i30 was evaluated as quantitative determination methods for PCT. The lower limit of detection for the both methods was 0.02 ng/ml. Correlation coefficients of 0.993 to 0.997 indicated good correlation between the two methods. The both methods allow quick and easy measurement of PCT, therefore they are helpful for diagnosis and severity evaluation of bacterial sepsis.