Subpial resection of epileptogenic tubers: operative nuances and lessons learned.

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disorder. Tubers of the central nervous system are a hallmark of the disorder and often cause epilepsy. Many TSC patients fail to achieve seizure control with medication alone. Several case series have demonstrated high seizure freedom rates after resective surgery. However, the technique for the resection of epileptogenic tubers has largely been unreported. Here the authors present 2 cases to illustrate their multistage approach for localizing and resecting the seizure onset zone in patients with TSC. At their institution, they have excellent seizure outcomes and a low complication rate with this technique. The video can be found here: https://stream.cadmore.media/r10.3171/2024.4.FOCVID2411.

Organophosphate pesticide exposure and risk of SARS-CoV-2 infection.

Several studies have reported immune modulation by organophosphate (OP) pesticides, but the relationship between OP exposure and SARS-CoV-2 infection is yet to be studied. We used two different measures of OP pesticide exposure (urinary biomarkers (N = 154) and residential proximity to OP applications (N = 292)) to examine the association of early-childhood and lifetime exposure to OPs and risk of infection of SARS-CoV-2 using antibody data. Our study population consisted of young adults (ages 18-21 years) from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) Study, a longitudinal cohort of families from a California agricultural region. Urinary biomarkers reflected exposure from in utero to age 5 years. Residential proximity reflected exposures between in utero and age 16 years. SARS-CoV-2 antibodies in blood samples collected between June 2022 and January 2023 were detected via two enzyme linked immunosorbent assays, each designed to bind to different SARS-CoV-2 antigens. We performed logistic regression for each measure of pesticide exposure, adjusting for covariates from demographic data and self-reported questionnaire data. We found increased odds of SARS-CoV-2 infection among participants with higher urinary biomarkers of OPs in utero (OR = 1.94, 95% CI: 0.71, 5,58) and from age 0-5 (OR = 1.90, 95% CI: 0.54, 6.95).

Subscapular abscesses: A literature review and evidence-based treatment guidelines.

Background: An intramuscular abscess of the subscapularis is a rare phenomenon but important pathology for surgeons to be aware of because clinical deterioration can be rapid and diagnosis difficult. The presentation often mimics other common shoulder pathologies with subacute shoulder pain and stiffness. Early diagnosis, antibiotics and surgical drainage are critical to reduce the spread and joint destruction. Methods: A search of PubMed and Google Scholar databases identified cases of subscapular intramuscular abscess. Data collected about each case included patient demographics, presentation, pathology, surgical treatment and outcome. The authors report one additional subscapular abscess case. Results: Data from 17 cases of subscapular abscess were found, 16 in the literature and one case described by the authors. Sixteen of 17 cases (94.1%) presented with shoulder pain and reduced range of motion worsening over a mean of 6.7 days prior to presentation. Surgical approaches utilised included a posterior inferomedial approach, deltoid-pectoral approach and one posterior inferolateral approach. Discussion and conclusions: From the limited data available regarding subscapular intramuscular abscess, the authors make the following recommendations: (1) Empirical antibiotics covering Staphylococcus aureus +/- methicillin-resistant Staphylococcus aureus, (2) drainage is indicated in all cases; and (3) tendon-sparing approaches can access an abscess in most locations within the subscapular space.

The inflammasome pathway is activated by dengue virus non-structural protein 1 and is protective during dengue virus infection.

Dengue virus (DENV) is a medically important flavivirus causing an estimated 50-100 million dengue cases annually, some of whom progress to severe disease. DENV non-structural protein 1 (NS1) is secreted from infected cells and has been implicated as a major driver of dengue pathogenesis by inducing endothelial barrier dysfunction. However, less is known about how DENV NS1 interacts with immune cells and what role these interactions play. Here we report that DENV NS1 can trigger activation of inflammasomes, a family of cytosolic innate immune sensors that respond to infectious and noxious stimuli, in mouse and human macrophages. DENV NS1 induces the release of IL-1ß in a caspase-1 dependent manner. Additionally, we find that DENV NS1-induced inflammasome activation is independent of the NLRP3, Pyrin, and AIM2 inflammasome pathways, but requires CD14. Intriguingly, DENV NS1-induced inflammasome activation does not induce pyroptosis and rapid cell death; instead, macrophages maintain cellular viability while releasing IL-1ß. Lastly, we show that caspase-1/11-deficient, but not NLRP3-deficient, mice are more susceptible to lethal DENV infection. Together, these results indicate that the inflammasome pathway acts as a sensor of DENV NS1 and plays a protective role during infection.

The Inflammasome Pathway is Activated by Dengue Virus Non-structural Protein 1 and is Protective During Dengue Virus Infection.

Dengue virus (DENV) is a medically important flavivirus causing an estimated 50-100 million dengue cases annually, some of whom progress to severe disease. DENV non-structural protein 1 (NS1) is secreted from infected cells and has been implicated as a major driver of dengue pathogenesis by inducing endothelial barrier dysfunction. However, less is known about how DENV NS1 interacts with immune cells and what role these interactions play. Here we report that DENV NS1 can trigger activation of inflammasomes, a family of cytosolic innate immune sensors that respond to infectious and noxious stimuli, in mouse and human macrophages. DENV NS1 induces the release of IL-1ß in a caspase-1 dependent manner. Additionally, we find that DENV NS1-induced inflammasome activation is independent of the NLRP3, Pyrin, and AIM2 inflammasome pathways, but requires CD14. Intriguingly, DENV NS1-induced inflammasome activation does not induce pyroptosis and rapid cell death; instead, macrophages maintain cellular viability while releasing IL-1ß. Lastly, we show that caspase-1/11-deficient, but not NLRP3-deficient, mice are more susceptible to lethal DENV infection. Together, these results indicate that the inflammasome pathway acts as a sensor of DENV NS1 and plays a protective role during infection.

Discovering spontaneous intracranial hypotension after failed middle meningeal artery embolization for subdural hematomas: illustrative cases.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a relatively rare and underdiagnosed disease. SIH can lead to subdural hematomas (SDHs) and other complications. SDHs secondary to SIH are difficult to manage, with no consensus in management, and SDHs commonly recur if underlying SIH is not treated. OBSERVATIONS: A 46-year-old male with vague sensory and orientation symptoms presented with bilateral SDHs, which were treated with middle meningeal artery (MMA) embolization and burr hole evacuation. The patient improved initially but had recurrent encephalopathy and SDHs. The patient received 3 epidural blood patches (EBPs) over 8 days with continued improvement. A 78-year-old female presented with headaches, and imaging revealed a left chronic SDH. She underwent MMA embolization and mini-craniotomy for SDH evacuation. Her symptoms returned and imaging revealed a recurrent SDH. Pan spine computed tomography myelography showed a high thoracic cerebrospinal fluid (CSF) leak. She underwent 3 EBPs over 8 days with neurological improvement and stabilization of her SDH. LESSONS: The authors show that, if SDH recurs after initial treatment with MMA embolization, then SIH should be strongly considered and treated with EBPs. Further investigation is required to determine the role of targeted or blind EBPs and the use of imaging to find the source of occult CSF leaks causing SIH.

SARS-CoV-2 Spike triggers barrier dysfunction and vascular leak via integrins and TGF-ß signaling.

Severe COVID-19 is associated with epithelial and endothelial barrier dysfunction within the lung as well as in distal organs. While it is appreciated that an exaggerated inflammatory response is associated with barrier dysfunction, the triggers of vascular leak are unclear. Here, we report that cell-intrinsic interactions between the Spike (S) glycoprotein of SARS-CoV-2 and epithelial/endothelial cells are sufficient to induce barrier dysfunction in vitro and vascular leak in vivo, independently of viral replication and the ACE2 receptor. We identify an S-triggered transcriptional response associated with extracellular matrix reorganization and TGF-ß signaling. Using genetic knockouts and specific inhibitors, we demonstrate that glycosaminoglycans, integrins, and the TGF-ß signaling axis are required for S-mediated barrier dysfunction. Notably, we show that SARS-CoV-2 infection caused leak in vivo, which was reduced by inhibiting integrins. Our findings offer mechanistic insight into SARS-CoV-2-triggered vascular leak, providing a starting point for development of therapies targeting COVID-19.

Molecular Determinants of Tissue Specificity of Flavivirus Nonstructural Protein 1 Interaction with Endothelial Cells.

Members of the mosquito-borne flavivirus genus such as dengue (DENV), West Nile (WNV), and Zika (ZIKV) viruses cause distinct diseases and affect different tissues. We previously found that the secreted flaviviral nonstructural protein 1 (NS1) interacts with endothelial cells and disrupts endothelial barrier function in a tissue-specific manner consistent with the disease tropism of the respective viruses. However, the underlying molecular mechanism of this tissue-specific NS1-endothelial cell interaction is not well understood. To elucidate the distinct role(s) that the wing and ß-ladder domains of NS1 play in NS1 interactions with endothelial cells, we constructed flavivirus NS1 chimeras that exchanged the wing and ß-ladder domains in a pairwise manner between DENV, WNV, and ZIKV NS1. We found that both the NS1 wing and ß-ladder domains conferred NS1 tissue-specific endothelial dysfunction, with the wing conferring cell binding and the ß-ladder involved in inducing endothelial hyperpermeability as measured by transendothelial electrical resistance. To narrow down the amino acids dictating cell binding specificity, we utilized the DENV-WNV NS1 chimera and identified residues 91 to 93 (GDI) of DENV NS1 as a molecular motif determining binding specificity. Further, using an in vivo mouse model of localized leak, we found that the GDI motif of the wing domain was essential for triggering DENV NS1-induced vascular leak in mouse dermis. Taken together, we identify molecular determinants of flavivirus NS1 that confer NS1 binding and vascular leak and highlight the importance of the NS1 wing domain for flavivirus pathogenesis. IMPORTANCE Flavivirus NS1 is secreted into the bloodstream from infected cells during a viral infection. Dengue virus NS1 contributes to severe dengue pathology such as endothelial dysfunction and vascular leak independently of the virus. We have shown that multiple flavivirus NS1 proteins result in endothelial dysfunction in a tissue-specific manner consistent with their respective viral tropism. Here, we aimed to identify the molecular determinants that make some, but not other, flavivirus NS1 proteins bind to select endothelial cells in vitro and cause vascular leak in a mouse model. We identified the wing domain of NS1 as a primary determinant conferring differential endothelial dysfunction and vascular leak and narrowed the contributing amino acid residues to a three-residue motif within the wing domain. The insights from this study pave the way for future studies on the effects of flavivirus NS1 on viral dissemination and pathogenesis and offer potential new avenues for antiviral therapies.

Development and Implementation of Dried Blood Spot-Based COVID-19 Serological Assays for Epidemiologic Studies.

Serological surveillance studies of infectious diseases provide population-level estimates of infection and antibody prevalence, generating crucial insight into population-level immunity, risk factors leading to infection, and effectiveness of public health measures. These studies traditionally rely on detection of pathogen-specific antibodies in samples derived from venipuncture, an expensive and logistically challenging aspect of serological surveillance. During the COVID-19 pandemic, guidelines implemented to prevent the spread of SARS-CoV-2 infection made collection of venous blood logistically difficult at a time when SARS-CoV-2 serosurveillance was urgently needed. Dried blood spots (DBS) have generated interest as an alternative to venous blood for SARS-CoV-2 serological applications due to their stability, low cost, and ease of collection; DBS samples can be self-generated via fingerprick by community members and mailed at ambient temperatures. Here, we detail the development of four DBS-based SARS-CoV-2 serological methods and demonstrate their implementation in a large serological survey of community members from 12 cities in the East Bay region of the San Francisco metropolitan area using at-home DBS collection. We find that DBS perform similarly to plasma/serum in enzyme-linked immunosorbent assays and commercial SARS-CoV-2 serological assays. In addition, we show that DBS samples can reliably detect antibody responses months postinfection and track antibody kinetics after vaccination. Implementation of DBS enabled collection of valuable serological data from our study population to investigate changes in seroprevalence over an 8-month period. Our work makes a strong argument for the implementation of DBS in serological studies, not just for SARS-CoV-2, but any situation where phlebotomy is inaccessible. IMPORTANCE Estimation of community-level antibody responses to SARS-CoV-2 from infection or vaccination is critical to inform public health responses. Traditional studies of antibodies rely on collection of blood via venipuncture, an invasive procedure not amenable to pandemic-related social-distancing measures. Dried blood spots (DBS) are an alternative to venipuncture, since they can be self-collected by study participants at home and do not require refrigeration for shipment or storage. However, DBS-based assays to measure antibody levels to SARS-CoV-2 have not been widely utilized. Here, we show that DBS are comparable to blood as a sampling method for antibody responses to SARS-CoV-2 infection and vaccination over time measured using four distinct serological assays. The DBS format enabled antibody surveillance in a longitudinal cohort where study participants self-collected samples, ensuring the participants' safety during an ongoing pandemic. Our work demonstrates that DBS are an excellent sampling method for measuring antibody responses whenever venipuncture is impractical.

The First Pilot Study of an Interactive, 360° Augmented Reality Visualization Platform for Neurosurgical Patient Education: A Case Series.

BACKGROUND: Interactive technologies are increasingly being used for patient education. Augmented reality (AR) is the technology of superimposing digital content on the reality that the user observes. OBJECTIVE: To evaluate a brand new, commercial prototype of a 360° AR visualization platform (360 ARVP) to enhance patient education for neurosurgical patients. METHODS: This pilot study was a single-center, single-provider study that took place in the clinic setting of the senior author. Patients were given the opportunity to use the 360 ARVP (Surgical Theater) concurrently with the neurosurgeon. All patients completed a survey on their experience with the 360 ARVP immediately after use. RESULTS: A total of 24 patients participated in the study. All patients (19 [79.2%] strongly agreed and 5 [20.8%] agreed) reported that using the 360 ARVP system helped improve understanding of their medical condition. The total percentage of patients who either agreed or strongly agreed that experiencing the 360 ARVP helped improve their comfort levels and that they felt included in decisions about their treatment was 95.8%. When asked to rate their level of understanding of their treatment plans on a 0 to 10 scale, the difference in means for the patients' ratings before and after the use of 360 ARVP was statistically significant (P < .0017). CONCLUSION: This pilot study demonstrates that AR can be used as an adjunctive tool for patient education. Patients found that the 360 ARVP increased their understanding of their medical conditions and improved their comfort level with the proposed treatments.

Transcriptional Regulation and Functional Characterization of the Plasmid-Borne oqxAB Genes in Salmonella Typhimurium.

Coexistence of oqxAB and aac(6')-Ib-cr is often associated with the expression of fluoroquinolone resistance in Salmonella. The actual role of the plasmid-borne oqxAB gene and its regulatory mechanism compared to its chromosomally encoded counterpart in Klebsiella pneumoniae remain unclear We found that cloning of oqxAB gene only or chromosomally encoded oqxABR (ABRc) locus did not lead to an increase of ciprofloxacin (CIP) minimum inhibitory concentration (MIC) in S. Typhimurium, while cloning of the plasmid-encoded oqxABR (ABRp) locus led to a 4-fold increase in CIP MIC, reaching 0.0065 µg/mL. The co-carriage of these constructs with aac(6')-Ib-cr further increased the CIP MIC to 0.25 µg/mL in S. Typhimurium carrying aac(6')-Ib-cr and ABRp. Analysis of the transcription start site sequences showed that the expression level of suppressor protein gene, oqxR, in strains carrying ABRp was lower than that of its chromosomal counterpart due to the truncated promoter region in ABRp. The lower expression of OqxR in ABRp led to the overexpression of OqxAB, which elevated CIP MIC and exhibited a synergistic antimicrobial effect with the aac(6')-Ib-cr gene product to confer intermediate CIP (MIC = 0.25 µg/mL) in S. Typhimurium. Global transcriptional regulators in S. Typhimurium did not seem to play a role in regulating the plasmid-borne oqxAB genes. In conclusion, findings in this work showed that neither aac(6')-Ib-cr nor oqxABRp, but the combination of both genes, could mediate intermediated resistance to fluoroquinolone in Salmonella. The truncated promoter region in the oqxR gene of the plasmid-encoded locus led to the constituted expression of oqxAB genes. IMPORTANCE The transferable mechanisms of quinolone resistance (TMQR) gene, oqxAB, has been widely detected in Salmonella and is commonly associated with aac(6')-Ib-cr. It is thought to be associated with fluoroquinolone resistance, while its ancestor gene from K. pneumoniae is not. This study evaluated the actual role of the plasmid-borne oqxAB genes in Salmonella and showed that it was not able to mediate intermediated resistance to fluoroquinolone and only did so when it coexisted with aac(6')-Ib-cr. Chromosomally encoded oqxABRc from K. pneumoniae was not able to mediate enhanced CIP MIC due to tight regulation by the suppressor oqxR. However, plasmid-encoded oqxABRp enabled oqxAB to be expressed constitutionally due to the truncated promoter region of oqxR, leading to lower expression of the suppressor oqxR. This study clarified the roles of oqxAB and aac(6')-Ib-cr in mediating fluoroquinolone resistance in Salmonella and provides insights into the regulation of plasmid-encoded TMQR determinant, oqxAB.

The Role of Instrumentation in the Surgical Treatment of Spondylodiscitis and Spinal Epidural Abscess: A Single-Center Retrospective Cohort Study.

BACKGROUND: Despite the high incidence of spinal infections that require an operation, there is no consensus on the most appropriate initial surgical management for these patients regarding decompression with vs without instrumented fusion. In this study, we investigated the differences in clinical outcomes, complication rates, and reoperation rates between patients with spinal epidural abscess who underwent decompression alone vs decompression with instrumented fusion. METHODS: Records of patients undergoing operative intervention for spondylodiscitis with spinal epidural abscess at the authors' institution between 2011 and 2018 were reviewed. Two cohorts were observed: patients who underwent decompression alone and patients who underwent decompression with instrumented fusion as the initial operation. Patient demographics and primary outcomes were analyzed and compared. RESULTS: Medical records of 74 patients with spinal infection were reviewed, and 47 patients met the inclusion criteria. There were 27 (57.4%) patients who underwent decompression alone and 20 (42.6%) patients who underwent decompression and fusion. There were no significant differences in the comorbidities, level, and/or extent of infectious involvement between the decompression alone cohort and the decompression with fusion cohort. Although no significant differences were seen between groups with regard to complication rates and neurological outcomes, the reoperation rate was significantly higher in the patients who underwent decompression alone (51.9% vs 10%, P = 0.004). CONCLUSIONS: Decompression with instrumented fusion delivers neurological outcomes and complication rates similar to those seen with decompression alone in patients with spondylodiscitis. However, there was a significantly higher reoperation rate in the decompression only cohort compared to the decompression and fusion cohort.

Health inequities in SARS-CoV-2 infection, seroprevalence, and COVID-19 vaccination: Results from the East Bay COVID-19 study.

Comprehensive data on transmission mitigation behaviors and both SARS-CoV-2 infection and serostatus are needed from large, community-based cohorts to identify COVID-19 risk factors and the impact of public health measures. We conducted a longitudinal, population-based study in the East Bay Area of Northern California. From July 2020-March 2021, approximately 5,500 adults were recruited and followed over three data collection rounds to investigate the association between geographic and demographic characteristics and transmission mitigation behavior with SARS-CoV-2 prevalence. We estimated the populated-adjusted prevalence of antibodies from SARS-CoV-2 infection and COVID-19 vaccination, and self-reported COVID-19 test positivity. Population-adjusted SARS-CoV-2 seroprevalence was low, increasing from 1.03% (95% CI: 0.50-1.96) in Round 1 (July-September 2020), to 1.37% (95% CI: 0.75-2.39) in Round 2 (October-December 2020), to 2.18% (95% CI: 1.48-3.17) in Round 3 (February-March 2021). Population-adjusted seroprevalence of COVID-19 vaccination was 21.64% (95% CI: 19.20-24.34) in Round 3, with White individuals having 4.35% (95% CI: 0.35-8.32) higher COVID-19 vaccine seroprevalence than individuals identifying as African American or Black, American Indian or Alaskan Native, Asian, Hispanic, two or more races, or other. No evidence for an association between transmission mitigation behavior and seroprevalence was observed. Despite >99% of participants reporting wearing masks individuals identifying as African American or Black, American Indian or Alaskan Native, Asian, Hispanic, two or more races, or other, as well as those in lower-income households, and lower-educated individuals had the highest SARS-CoV-2 seroprevalence and lowest vaccination seroprevalence. Results demonstrate that more effective policies are needed to address these disparities and inequities.

Stress hematopoiesis induces a proliferative advantage in TET2 deficiency.

TET2 loss-of-function mutations are recurrent events in a wide range of hematological malignancies and a physiologic occurrence in blood cells of healthy older adults. It is currently unknown what determines if a person harboring a somatic TET2 mutation will progress to myelodysplastic syndrome or acute myeloid leukemia. Here we develop a zebrafish tet2 mutant through which we show that tet2 loss leads to restricted hematopoietic differentiation combined with a modest upregulation of p53, which is also characteristic of many inherited bone marrow failure syndromes. Uniquely in the context of emergency hematopoiesis by external stimuli, such as infection or cytokine stimulation, lack of tet2 leads hematopoietic stem cells to undergo excessive proliferation, resulting in an accumulation of immature cells, which are poised to become leukemogenic following additional genetic/epigenetic perturbations. This same phenomenon observed in zebrafish extends to human hematopoietic stem cells, identifying TET2 as a critical relay switch in the context of stress hematopoiesis.

Optimization of magnetic bead-based nucleic acid extraction for SARS-CoV-2 testing using readily available reagents.

The COVID-19 pandemic has highlighted the need for generic reagents and flexible systems in diagnostic testing. Magnetic bead-based nucleic acid extraction protocols using 96-well plates on open liquid handlers are readily amenable to meet this need. Here, one such approach is rigorously optimized to minimize cross-well contamination while maintaining sensitivity.

SARS-CoV-2 Spike triggers barrier dysfunction and vascular leak via integrins and TGF-ß signaling.

Severe COVID-19 is associated with epithelial and endothelial barrier dysfunction within the lung as well as in distal organs. While it is appreciated that an exaggerated inflammatory response is associated with barrier dysfunction, the triggers of this pathology are unclear. Here, we report that cell-intrinsic interactions between the Spike (S) glycoprotein of SARS-CoV-2 and epithelial/endothelial cells are sufficient to trigger barrier dysfunction in vitro and vascular leak in vivo , independently of viral replication and the ACE2 receptor. We identify an S-triggered transcriptional response associated with extracellular matrix reorganization and TGF-ß signaling. Using genetic knockouts and specific inhibitors, we demonstrate that glycosaminoglycans, integrins, and the TGF-ß signaling axis are required for S-mediated barrier dysfunction. Our findings suggest that S interactions with barrier cells are a contributing factor to COVID-19 disease severity and offer mechanistic insight into SARS-CoV-2 triggered vascular leak, providing a starting point for development of therapies targeting COVID-19 pathogenesis.

Structural and Functional Characterization of OXA-48: Insight into Mechanism and Structural Basis of Substrate Recognition and Specificity.

Class D ß-lactamase OXA-48 is widely distributed among Gram-negative bacteria and is an important determinant of resistance to the last-resort carbapenems. Nevertheless, the detailed mechanism by which this ß-lactamase hydrolyzes its substrates remains poorly understood. In this study, the complex structures of OXA-48 and various ß-lactams were modeled and the potential active site residues that may interact with various ß-lactams were identified and characterized to elucidate their roles in OXA-48 substrate recognition. Four residues, namely S70, K73, S118, and K208 were found to be essential for OXA-48 to undergo catalytic hydrolysis of various penicillins and carbapenems both in vivo and in vitro. T209 was found to be important for hydrolysis of imipenem, whereas R250 played a major role in hydrolyzing ampicillin, imipenem, and meropenem most likely by forming a H-bond or salt-bridge between the side chain of these two residues and the carboxylate oxygen ions of the substrates. Analysis of the effect of substitution of alanine in two residues, W105 and L158, revealed their roles in mediating the activity of OXA-48. Our data show that these residues most likely undergo hydrophobic interaction with the R groups and the core structure of the ß-lactam ring in penicillins and the carbapenems, respectively. Unlike OXA-58, mass spectrometry suggested a loss of the C6-hydroxyethyl group during hydrolysis of meropenem by OXA-48, which has never been demonstrated in Class D carbapenemases. Findings in this study provide comprehensive knowledge of the mechanism of the substrate recognition and catalysis of OXA-type ß-lactamases.

Risk Factors Associated With SARS-CoV-2 Infection Among Farmworkers in Monterey County, California.

Importance: Essential workers in agriculture and food production have been severely affected by the ongoing COVID-19 pandemic. Objective: To identify risk factors associated with SARS-CoV-2 infection among farmworkers in California. Design, Setting, and Participants: This cross-sectional study invited farmworkers in California's Salinas Valley (Monterey County) receiving transcription-mediated amplification (TMA) tests for SARS-CoV-2 infection at federally qualified community clinics and community sites to participate. Individuals were eligible if they were not pregnant, were 18 years or older, had conducted farmwork since the pandemic started, and were proficient in English or Spanish. Survey data were collected and SARS-CoV-2 tests were conducted among participants from July 16 to November 30, 2020. Exposures: Sociodemographic, household, community, and workplace characteristics. Main Outcomes and Measures: TMA- and immunoglobulin G (IgG)-positive SARS-CoV-2 infection. Results: A total of 1107 farmworkers (581 [52.5%] women; mean [SD] age, 39.7 [12.6] years) were included in these analyses. Most participants were born in Mexico (922 [83.3%]), were married or living with a partner (697 [63.0%]), and worked in the fields (825 [74.5%]). Overall, 118 of 911 (13.0%) had a positive result on their TMA test for SARS-CoV-2 infection, whereas 201 of 1058 (19.0%) had antibody evidence of infection. In multivariable analyses accounting for recruitment venue and enrollment period, the incidence of TMA-positive SARS-CoV-2 infection was higher among those with lower than primary school-level education (adjusted relative risk [aRR], 1.32; 95% CI, 0.99-1.76; non-statistically significant finding), who spoke an Indigenous language at home (aRR, 1.30; 95% CI, 0.97-1.73; non-statistically significant finding), who worked in the fields (aRR, 1.60; 95% CI, 1.03-2.50), and who were exposed to a known or suspected COVID-19 case at home (aRR, 2.98; 95% CI, 2.06-4.32) or in the workplace (aRR, 1.59; 95% CI, 1.18-2.14). Positive results on IgG tests for SARS-CoV-2 infection were more common among those who lived in crowded housing (aRR, 1.23; 95% CI, 0.98-1.53; non-statistically significant finding), with children aged 5 years or younger (aRR, 1.40; 95% CI, 1.11-1.76), with unrelated roommates (aRR, 1.40; 95% CI, 1.19-1.64), and with an individual with known or suspected COVID-19 (aRR, 1.59; 95% CI, 1.13-2.24). The risk of IgG positivity was also higher among those with body mass index of 30 or greater (aRR, 1.65; 95% CI, 1.01-2.70) or diabetes (aRR, 1.31; 95% CI, 0.98-1.75; non-statistically significant finding). Conclusions and Relevance: In this cross-sectional study of farmworkers in California, both residential and workplace exposures were associated with SARS-CoV-2 infection. Urgent distribution of COVID-19 vaccines and intervention on modifiable risk factors are warranted given this population's increased risk of infection and the essential nature of their work.

Active maintenance of proton motive force mediates starvation-induced bacterial antibiotic tolerance in Escherichia coli.

Recent evidence suggests that metabolic shutdown alone does not fully explain how bacteria exhibit phenotypic antibiotic tolerance. In an attempt to investigate the range of starvation-induced physiological responses underlying tolerance development, we found that active maintenance of the transmembrane proton motive force (PMF) is essential for prolonged expression of antibiotic tolerance in bacteria. Eradication of tolerant sub-population could be achieved by disruption of PMF using the ionophore CCCP, or through suppression of PMF maintenance mechanisms by simultaneous inhibition of the phage shock protein (Psp) response and electron transport chain (ETC) complex activities. We consider disruption of bacterial PMF a feasible strategy for treatment of chronic and recurrent bacterial infections.