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ABSTRACTEscherichia colisequence type 131 (ST131) and ST405 are important clonal groups, because they are associated with the global increase of extended-spectrum-ß-lactamase (ESBL) producers. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is emerging as a rapid, inexpensive, and accurate method for bacterial identification. We investigated the detection performance of MALDI-TOF for the ST131 and ST405 clonal groups using 41 ST131-O25b, 26 ST131-O16, and 41 ST405 ESBL-producing isolates and 41 ESBL-producing isolates frrom other STs. The main spectra representing each clonal group were used for classification with Biotyper (Bruker Daltonics GmbH, Bremen, Germany). The peak that had the highest area under the receiver-operating characteristic curve generated by ClinProTools (Bruker) was detected with FlexAnalysis (Bruker), and an optimal signal-to-noise ratio cutoff was determined. The optimal detection models were generated by ClinProTools. Classification by Biotyper could detect the ST131-whole (O25b and O16 together) group with a sensitivity of 98.5% and a specificity of 93.9%. With FlexAnalysis, a peak of 9,720 Da detected the ST131-whole group with a sensitivity of 97.0% and a specificity of 91.5% at a cutoff value of 8.0. The ClinProTools models exhibited good performance for the detection of the ST131-whole group (sensitivity and specificity, 94.0% and 92.7%, respectively), the ST131-O25b group (95.1% and 98.2%, respectively), and the ST405 group (90.2% and 96.3%, respectively). MALDI-TOF MS had high detection performance for the ST131-whole, ST131-O25b, and ST405 clonal groups. MALDI-TOF MS should be considered as an alternative method to monitor the epidemiology of the ESBL-producing E. coliST131 and ST405 clonal groups.

ABSTRACTThe aim of this study was to evaluate the performance of the transcription-reverse transcription concerted (TRC) method for the detection of Mycobacterium tuberculosiscomplex (MTC) 16S rRNA in clinical respiratory samples for the diagnosis of pulmonary tuberculosis. TRC is a novel method that enables the rapid and the completely homogeneous real-time monitoring of isothermal sequence RNA amplification without any postamplification procedure. The detection limit of the TRC method for MTC was one organism per 100 µl of sputum. The specificity of the method was confirmed by the absence of positive signals for sputum containing 106M. aviumor M. kansasiiorganisms per 100 µl. A total of 201 respiratory samples from patients diagnosed with or suspected of having tuberculosis were tested. Of the 72 MTC culture-positive samples, the TRC method was positive for 52 (sensitivity, 72.2%), whereas the Roche COBAS AMPLICOR PCR was positive for 58 (sensitivity, 80.6%). Both the TRC method and the COBAS AMPLICOR PCR showed no positive identification for any of the 129 culture-negative samples. The percent agreement between the two methods was 95% (191 of 201 samples). The high sensitivity and specificity together with shorter detection time (within 1 h) of the TRC method allow it to be proposed as a useful method for the rapid detection of MTC in respiratory samples.

Necrotizing fasciitis caused by Haemophilus influenzaetype b is a rare infection of the skin and soft tissues. The only previously reported case involved a healthy infant. We report herein the case of an 81-year-old Japanese woman with diabetes mellitus who developed necrotizing fasciitis caused by H. influenzaetype b.

ABSTRACTPsittacosis infection is usually reported in adults aged around 30 to 60 years. We report here two cases of psittacosis in an elderly couple (76 and 77 years old) who jointly ran a pet shop. Psittacosis was diagnosed from a history of exposure to birds and from serological testing for Chlamydophilia avium.