Preparedness and response of assisted living facilities toward COVID-19 infection control in Houston, Texas, USA.

Background: Long-term care facilities (LTCFs) including assisted living facilities (ALFs) are hubs for high transmission and poor prognosis of COVID-19 among the residents who are more susceptible due to old age and comorbidities. Aim: Houston Health Department conducted assessments of ALFs within the City of Houston to determine preparedness and existing preventive measures at the facilities. Methods: Onsite assessments were conducted at ALFs using a modified CDC Infection Control Assessment and Response (ICAR) Tool. Data was obtained on IPC measures, training, testing, vaccination etc. Data was analyzed, frequencies generated, and bivariate associations determined. Results: A total of 118 facilities were assessed and categorized into small scale 46 (39%), medium scale 47 (40%), and large scale 25 (21%). The facilities had 2431 residents and 2290 staff. Thirty-one (26%) facilities reported an outbreak in 2020, while 14 (12%) had an ongoing outbreak. Twenty-three (97%) large-scale and 12 (26%) small-scale facilities had COVID-19 testing program. Vaccination coverage among residents ranged from 99% in large-scale to 40% in small-scale facilities but was smaller among staff at 748 (45%) in large scale, 71 (36%) in small scale, and 193 (45%) in medium scale. While 24 (96%) large-scale and 34 (77%) of small-scale facilities conducted staff training staff on IPC practices, 22 (92%) of large-scale and 19 (56%) of small-scale facility staff demonstrated capacity (p = 0.01), respectively. Visitor screening was done at 100% of large-scale and 80% of small-scale and the medium-scale ALFs. Discussion: Assisted living facilities within the city of Houston are at various levels of preparedness and interventions with respect to COVID-19 response.

Degradation of complex arabinoxylans by human colonic Bacteroidetes.

Some Bacteroidetes and other human colonic bacteria can degrade arabinoxylans, common polysaccharides found in dietary fiber. Previous work has identified gene clusters (polysaccharide-utilization loci, PULs) for degradation of simple arabinoxylans. However, the degradation of complex arabinoxylans (containing side chains such as ferulic acid, a phenolic compound) is poorly understood. Here, we identify a PUL that encodes multiple esterases for degradation of complex arabinoxylans in Bacteroides species. The PUL is specifically upregulated in the presence of complex arabinoxylans. We characterize some of the esterases biochemically and structurally, and show that they release ferulic acid from complex arabinoxylans. Growth of four different colonic Bacteroidetes members, including Bacteroides intestinalis, on complex arabinoxylans results in accumulation of ferulic acid, a compound known to have antioxidative and immunomodulatory properties.

Simultaneous measurement of total estradiol and testosterone in human serum by isotope dilution liquid chromatography tandem mass spectrometry.

Reliable measurement of total testosterone and estradiol is critical for their use as biomarkers of hormone-related disorders in patient care and translational research. We developed and validated a mass spectrometry method to simultaneously quantify these analytes in human serum without chemical derivatization. Serum is equilibrated with isotopic internal standards and treated with acidic buffer to release hormones from their binding proteins. Lipids are isolated and polar impurities are removed by two serial liquid-liquid extraction steps. Total testosterone and estradiol are measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) in combination of positive and negative electrospray ionization modes. The method shows broad analytical measurement range for both testosterone 0.03-48.5 nM (0.75-1400 ng/dL) and estradiol 11.0-5138 pM (2.99-1400 pg/mL) and excellent agreement with certified reference materials (mean bias less than 2.1% to SRM 971, BCR 576, 577, and 578) and a high order reference method (mean bias 1.25% for testosterone and -0.84% for estradiol). The high accuracy of the method was monitored and certified by CDC Hormone Standardization (HoSt) Program for 2 years with mean bias -0.7% (95% CI -1.6% to 0.2%) for testosterone and 0.1% (95% CI -2.2% to 2.3%) for estradiol. The method precision over a 2-year period for quality control pools at low, medium, and high concentrations was 2.7-2.9% for testosterone and 3.3-5.3% for estradiol. With the consistently excellent accuracy and precision, this method is readily applicable for high-throughput clinical and epidemiological studies.