Automatic Identification of MALDI-TOF MS Database Using Classical Bordetella Species Isolates.

Objective: To evaluate and expand the automatic identification and clustering of clinical Bordetella species by MALDI-TOF MS. Methods: Twenty-eight field isolated strains, identified by whole-gene sequencing analysis, were analyzed by MALDI-TOF MS, and the spectra obtained were used to replenish the internal database of the manufacturer. To evaluate and expand the robustness of the database, MALDI-TOF MS identified 91 clinical isolates (except those used for implementation). A distance tree based on mass spectrometry data is constructed to confirm similarity and clusters of each clinical Bordetella species by using the MALDI Biotyper 3.1 software. Results: In this research, when we used the implemented Bruker Daltonics database in our laboratory, 91 clinical isolates were identified at the genus level (100%) and 93.4% were identified at the species level (85/91). We performed proteomics analysis and divided these 91 isolates into cluster I (2.2%) and cluster II (97.8%). The largest group is cluster II (n = 89 isolates), which has been divided into two subclusters. Trees created by analyzing the protein mass spectra of the three species of the clinical isolates reflected their classification. Conclusion: MALDI-TOF MS may present an attractive alternative to automatically confirm and cluster the fastidious bacteria difficult to culture. Extension of identification of the MALDI-TOF MS database is viably fast, more efficient, and alternative to conventional methods in confirming the classical Bordetella species. This strategy could promote the epidemiological and taxonomic research of this important pathogen.

Epidemiological and clinical characteristics of bacteremic brucellosis.

OBJECTIVE: To retrospectively investigate the epidemiological features, clinical manifestations and laboratory characteristics of bacteremic brucellosis. METHODS: Brucellosis patients admitted to our clinic from January 2015 to December 2017 were included in the study. Patient electronic medical records were reviewed for epidemiological features, clinical manifestations, and laboratory findings. RESULTS: A total of 132 brucellosis patients were analyzed (64 cases with bacteremic brucellosis and 68 cases with nonbacteremic brucellosis). The median duration from exposure to onset of symptoms was 6.9 weeks (range: 1 day to 32 weeks) and 21.9 weeks (range: 1-76 weeks) in patients with bacteremic and nonbacteremic brucellosis, respectively. More bacteremic than nonbacteremic patients presented with fever and chills. Arthritis was observed in 34 (25.8%) patients, and was more commonly observed in nonbacteremic patients. Using C-reactive protein (CRP) and procalcitonin (PCT) as serological markers, the areas under the receiving operating characteristic curves were 0.64 [95% confidence interval (CI): 0.54-0.73] and 0.61 (95% CI: 0.51-0.70), respectively, for distinguishing bacteremic from non-bacteremic brucellosis. CONCLUSION: Fever and chills were frequently observed in bacteremic brucellosis patients, whereas arthritis was more common in nonbacteremic brucellosis patients. Serum CRP and PCT can be used as potential serological markers for diagnosing bacteremic brucellosis.

Stress state measured at ~7 km depth in the Tarim Basin, NW China.

The in-situ stress state in the Tarim Basin, Northwest China, down to 7 km depth is constrained using the anelastic strain recovery (ASR) method and wellbore failure analysis. Results are consistent between the two methods, and indicate that the maximum principal stresses (σ1) are close to vertical and the intermediate and minimum principal stresses (σ2 and σ3) are approximately horizontal. The states of stress at the studied wellbore is in the normal faulting stress regime within the Tarim Basin rather than in the compressional tectonic stress regime as in the periphery of the Tarim Basin, which explains the presence of the normal faults interpreted in 3-D seismic profiles collected from adjacent areas. Our results demonstrate that the ASR method can be used for rocks recovered from depths as deep as 7 km to recover reliable stress state information. The in-situ stress measurement results revealed in this paper will help future development of the petroleum resources and kinematics study in the Tarim Basin.