Novel quinoxaline compound against extended-spectrum beta-lactamases producing bacteria.

OBJECTIVE: Extended-spectrum beta-lactamases (ESBLs) targeting beta-lactam antibiotics pose a major healthcare challenge. Carbapenems are known to be less impacted. However, the emergence of carbapenem-resistant strains can add further complexity to this existing challenge. With slow drug discovery and rapid resistance, repurposing existing drugs is crucial. This research study aims to provide insight into the antimicrobial effectiveness of 3-hydrazinoquinoxaline-2-thiol against diverse clinical ESBL-producing isolates. MATERIALS AND METHODS: The broth microdilution assay was conducted on a total of sixty-nine clinical ESBL-producing isolates to assess the minimum inhibitory concentrations (MICs) of 3-hydrazinoquinoxaline-2-thiol. The assay was conducted in triplicate, and the average MIC values were calculated. RESULTS: The most repeatedly observed MIC was 64 µg/ml (37.7%), followed by 256 µg/ml (23.2%) and 128 µg/ml (17.4%). Other MICs: 32 µg/ml (11.6%), 16 µg/ml (7.2%), 4-8 µg/ml (1.4%). CONCLUSIONS: This study demonstrated an effect of 3-hydrazinoquinoxaline-2-thiol on various ESBL-producing strains in vitro, indicating its promising therapeutic potential. To comprehensively understand the drug, rigorous testing, including pharmacokinetics, resistance assays, safety assessments, and exploration of potential synergies with other antibiotics against ESBL-producing organisms, is crucial.

Growth factors in relation to obesity, food habits, and microbiota among healthy Saudis: preliminary results.

OBJECTIVE: Obesity is a serious problem among Saudis because of the country's affluent lifestyle. Obesity is associated with various metabolic disorders and characterized by low-grade inflammation that leads to the release of pro-inflammatory cytokines, human growth factors (GFs), lipids, aberrant adipokines, and other chemokines from adipose tissue. The objective of this study is to delineate the effects of GFs on microbiota and their relationship to body mass index (BMI) and food habits. SUBJECTS AND METHODS: In a cross-sectional study, 32 randomly selected participants (16 males and 16 females) were enrolled in a survey covering their sociodemographic information, medical history, lifestyle, and dietary practices. The information on diet, health condition, food and drink intake habits were examined under four distinct BMI categories: normal, underweight, overweight, and obese. The participants' serum samples were analyzed for the various GFs using a human magnetic 30-plex panel multiplex assay. Bioinformatics analysis was performed to investigate which bacterial taxa are enriched and to predict the functional profiles of the samples. RESULTS: Correlational studies revealed sex-based differences between GFs and microbiota. Females exhibited a significant correlation between epidermal GF (EGF) and Proteobacteria, whereas males showed a significant correlation between fibroblast GF-basic and Actinobacteria. Interestingly, a combined analysis of both sexes showed a significant correlation between EGF and vascular endothelial GF with Firmicutes. The data in the underweight group revealed a correlation between granulocyte colony-stimulating factor (G-CSF) and hepatocyte GF with Firmicutes. In the obese group, a correlation was found between G-CSF and Actinobacteria. CONCLUSIONS: Our results identified links between GFs, microbiota, and BMI in a Saudi cohort. The insights from this preliminary study will contribute to the predictive diagnosis of obesity. However, further research involving a larger cohort will be necessary to understand the mechanistic aspects of these GFs to provide biomarkers of potential obesity.

Nitrifying moving bed biofilm reactor (MBBR) biofilm and biomass response to long term exposure to 1 °C.

This study aims to investigate moving bed biofilm reactor (MBBR) nitrification rates, nitrifying biofilm morphology, biomass viability as well as bacterial community shifts during long-term exposure to 1 °C. Long-term exposure to 1 °C is the key operational condition for potential ammonia removal upgrade units to numerous northern region treatment systems. The average laboratory MBBR ammonia removal rate after long-term exposure to 1 °C was measured to be 18 ± 5.1% as compared to the average removal rate at 20 °C. Biofilm morphology and specifically the thickness along with biomass viability at various depths in the biofilm were investigated using variable pressure electron scanning microscope (VPSEM) imaging and confocal laser scanning microscope (CLSM) imaging in combination with viability live/dead staining. The biofilm thickness along with the number of viable cells showed significant increases after long-term exposure to 1 °C. Hence, this study observed nitrifying bacteria with higher activities at warm temperatures and a slightly greater quantity of nitrifying bacteria with lower activities at cold temperatures in nitrifying MBBR biofilms. Using DNA sequencing analysis, Nitrosomonas and Nitrosospira (ammonia oxidizers) as well as Nitrospira (nitrite oxidizer) were identified and no population shift was observed between 20 °C and after long-term exposure to 1 °C.