Antimicrobial resistance and molecular characterization of Escherichia coli isolated from bovine mastitis samples in Nghe An province, Vietnam.

Background and Aim: Vietnam's dairy sector is in its early phase of large-scale farming development. Therefore, mastitis in cows is always a concern to farm owners. This study aimed to determine the antimicrobial susceptibility, resistance, and virulence-related genes of Escherichia coli isolated from bovine mastitis in Nghe An province of Vietnam. Materials and Methods: Fifty E. coli strains were isolated from the clinical cases and subjected to this study. All isolates were tested for antimicrobial susceptibility by the disk-diffusion method, as described by the Clinical and Laboratory Standards Institute. Antimicrobial and virulence genes were confirmed by polymerase chain reaction with specific primers. Results: All isolates were resistant to lincomycin and sulfamethoxazole and sensitive to gentamicin, while other antimicrobials showed resistance from 2% to 90%. Multidrug resistance was confirmed in 46% of isolates, and none of them were identified as extended-spectrum beta-lactamase producers. From fifty strains tested for antimicrobial and virulence genes, six isolates harbored tetA, 6 tetB, 13 sul1, 15 sul2, 2 Intimin (eae), 1 iutA, and 3 stx2. Conclusion: Antimicrobial and multidrug resistances are the main virulence factors of E. coli isolated from bovine mastitis in Vietnam. The virulence genes encoding adhesion, siderophore, Shiga-toxin-producing, and antimicrobials resistant were first reported in Vietnam with low prevalence and contributed to the pathogenesis.

Auxin production of the filamentous cyanobacterial Planktothricoides strain isolated from a polluted river in Vietnam.

Cyanobacteria are photosynthetic microorganisms with widespread diversity and extensive global distribution. They produce a wide variety of bioactive substances (e.g., lipopeptides, fatty acids, toxins, carotenoids, vitamins and plant growth regulators) that are released into culture media. In this study, the capability of a cyanobacterial strain of Planktothricoides raciborskii to produce intra- and extracellular auxins was investigated. The filamentous cyanobacterial P. raciborskii strain was isolated from a river in Vietnam, and it was cultivated in the laboratory under the optimum conditions of the BG11 culture medium and a pH of 7.0. The auxins were identified and quantified by the Salkowski colorimetric method and high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Colorimetric analysis revealed that P. raciborskii produces extracellular indole-3-acetic acid (IAA) in the absence and presence of l-tryptophan. The maximum extracellular IAA concentration of the culture reached 118 ± 2 µg mL-1, which was supplemented with 900 µg mL-1 of l-tryptophan. HPLC-MS analysis revealed that the isolated cyanobacteria accumulate other plant-growth-promoting hormones besides IAA, such as indole-3-carboxylic acid (ICA), indole-3 butyric acid (IBA) and indole propionic acid (IPA). This is the first report on the production of auxins in an isolated strain of cyanobacteria Planktothricoides from a polluted river. The capability of producing auxins makes the P. raciborskii strain an appropriate candidate for the formulation of a biofertilizer.

Exhaled Nitric Oxide as a Surrogate Marker for Obstructive Sleep Apnea Severity Grading: An In-Hospital Population Study.

PURPOSE: Our study aimed to evaluate the relationship between exhaled nitric oxide (eNO) markers and obstructive sleep apnea (OSA) severity and verify the changes in eNO profiles among mild, moderate, and severe OSA subgroups. METHODS: This study was a cross-sectional and in-hospital population-based study. We investigated 123 OSA patients (17 mild, 23 moderate and, 83 severe OSA) in the department of respiratory diseases. Studied data included anthropometry, respiratory polygraphy, biological markers, spirometry, and multi-flow eNO measurements. Data analysis implied linear correlation, non-parametric ANOVA, and pair-wise comparison. RESULTS: No significant difference could be found among 3 OSA severity subgroups for FENO at - four sampling flow rates (50-350 mL/s). The bronchial production rate of NO (J'awNO) was proportionally increased, with median values of 11.2, 33.9, and 36.2 in mild, moderate, and severe OSA, respectively (p=0.010). The alveolar concentration of NO (CANO) changed with a non-linear pattern; it was increased in moderate (6.49) vs mild (7.79) OSA but decreased in severe OSA (5.20, p = 0.015). The only correction that could be established between OSA severity and exhaled nitric oxide markers is through J'AWNO (rho=0.25, p=0.02) and CANO (rho= 0.18, p=0.04). There was no significant correlation between FENO measured at three different flow rates and the OSA severity. We also found a weak but significant correlation between FENO 100 and averaged SpO2 (rho = 0.07, p= 0.03). CONCLUSION: The present study showed that J'AWNO, which represents eNO derived from the central airway, is proportionally increased in more severe OSA, while eNO from alveolar space, indicated by CANO, was also associated with OSA severity and relatively lower in the most severe OSA patients. In contrast, stand-alone FENO metrics did not show a clear difference among the three severity subgroups.

Degranulation of human cytotoxic lymphocytes is a major source of proteolytically active soluble CD26/DPP4.

Dipeptidyl peptidase 4 (DPP4, CD26) is a serine protease detected on several immune cells and on epithelial cells of various organs. Besides the membrane-bound enzyme, a catalytically active soluble form (sCD26/DPP4) is detected in several body fluids. Both variants cleave off dipeptides from the N-termini of various chemokines, neuropeptides, and hormones. CD26/DPP4 plays a fundamental role in the regulation of blood glucose levels by inactivating insulinotropic incretins and CD26/DPP4 inhibitors are thus routinely used in diabetes mellitus type 2 therapy to improve glucose tolerance. Such inhibitors might also prevent the CD26/DPP4-mediated inactivation of the T-cell chemoattractant CXCL10 released by certain tumors and thus improve anti-tumor immunity and immunotherapy. Despite its implication in the regulation of many (patho-)physiological processes and its consideration as a biomarker and therapeutic target, the cellular source of sCD26/DPP4 remains highly debated and mechanisms of its release are so far unknown. In line with recent reports that activated T lymphocytes could be a major source of sCD26/DPP4, we now demonstrate that CD26/DPP4 is stored in secretory granules of several major human cytotoxic lymphocyte populations and co-localizes with effector proteins such as granzymes, perforin, and granulysin. Upon stimulation, vesicular CD26/DPP4 is rapidly translocated to the cell surface in a Ca2+-dependent manner. Importantly, activation-induced degranulation leads to a massive release of proteolytically active sCD26/DPP4. Since activated effector lymphocytes serve as a major source of sCD26/DPP4, these results might explain the observed disease-associated alterations of sCD26/DPP4 serum levels and also indicate a so far unknown role of CD26/DPP4 in lymphocyte-mediated cytotoxicity.

[Study about the prevalence of the obstructive sleep apnoea syndrome in Vietnam]. / Étude de la prévalence du syndrome d'apnées obstructives du sommeil au Vietnam.

INTRODUCTION: Epidemiological studies on obstructive sleep apnoea syndrome (OSAS) in Asia, South East Asia in particular, are few. The EPSASIE study aimed to determine the prevalence of OSAS in an adult Vietnamese population and to describe its characteristics. METHODS: This is a prospective, observational, multicenter study. Nocturnal ventilatory polygraphy (PV) or polysomnography (PSG) were performed in patients having symptoms evocative of the SAS syndrome and an index of respiratory events (IER)>10/h or>25 in one hour, measured by RU Sleeping. RESULTS: A total of 667/750 validated questionnaires were received. The mean age of the study population was 44±12 years with a mean body mass index of 21.6±5.2kg/m2. PV or PSG were performed on 93 subjects after positive screening by RU Sleeping. OSAS with an apnoea-hypopnoea index (AHI)>5 was found in 57 subjects (8.5%) and in 35 subjects with AHI>15 (5.2% of cases). CONCLUSION: The prevalence of OSAS is quite high in the Vietnamese population and comparable with current literature data.