Cultivating efficiency: high-throughput growth analysis of anaerobic bacteria in compact microplate readers.

Anaerobic microbes play crucial roles in environmental processes, industry, and human health. Traditional methods for monitoring the growth of anaerobes, including plate counts or subsampling broth cultures for optical density measurements, are time and resource-intensive. The advent of microplate readers revolutionized bacterial growth studies by enabling high-throughput and real-time monitoring of microbial growth kinetics. Yet, their use in anaerobic microbiology has remained limited. Here, we present a workflow for using small-footprint microplate readers and the Growthcurver R package to analyze the kinetic growth metrics of anaerobic bacteria. We benchmarked the small-footprint Cerillo Stratus microplate reader against a BioTek Synergy HTX microplate reader in aerobic conditions using Escherichia coli DSM 28618 cultures. The growth rates and carrying capacities obtained from the two readers were statistically indistinguishable. However, the area under the logistic curve was significantly higher in cultures monitored by the Stratus reader. We used the Stratus to quantify the growth responses of anaerobically grown E. coli and Clostridium bolteae DSM 29485 to different doses of the toxin sodium arsenite. The growth of E. coli and C. bolteae was sensitive to arsenite doses of 1.3 µM and 0.4 µM, respectively. Complete inhibition of growth was achieved at 38 µM arsenite for C. bolteae and 338 µM in E. coli. These results show that the Stratus performs similarly to a leading brand of microplate reader and can be reliably used in anaerobic conditions. We discuss the advantages of the small format microplate readers and our experiences with the Stratus. IMPORTANCE: We present a workflow that facilitates the production and analysis of growth curves for anaerobic microbes using small-footprint microplate readers and an R script. This workflow is a cost and space-effective solution to most high-throughput solutions for collecting growth data from anaerobic microbes. This technology can be used for applications where high throughput would advance discovery, including microbial isolation, bioprospecting, co-culturing, host-microbe interactions, and drug/toxin-microbial interactions.

Cultivating efficiency: High-throughput growth analysis of anaerobic bacteria in compact microplate readers.

Anaerobic microbes play crucial roles in environmental processes, industry, and human health. Traditional methods for monitoring the growth of anaerobes, including plate counts or subsampling broth cultures for optical density measurements, are time and resource intensive. The advent of microplate readers revolutionized bacterial growth studies by enabling high-throughput and real-time monitoring of microbial growth kinetics but their use in anaerobic microbiology has remained limited. Here, we present a workflow for using small-footprint microplate readers and the Growthcurver R package to analyze the kinetic growth metrics of anaerobic bacteria. We benchmarked the small-footprint Cerillo Stratus microplate reader against a BioTek Synergy HTX microplate reader in aerobic conditions using Escherichia coli DSM 28618 cultures. The growth rates and carrying capacities obtained from the two readers were statistically indistinguishable. However, the area under the logistic curve was significantly higher in cultures monitored by the Stratus reader. We used the Stratus to quantify the growth responses of anaerobically grown E. coli and Clostridium bolteae DSM 29485 to different doses of the toxin sodium arsenite. The growth of E. coli and C. bolteae was sensitive to arsenite doses of 1.3 µM and 0.4 µM, respectively. Complete inhibition of growth was achieved at 38 µM arsenite for C. bolteae, and 338 µM in E. coli. These results show that the Stratus performs similarly to a leading brand of microplate reader and can be reliably used in anaerobic conditions. We discuss the advantages of the small format microplate readers and our experiences with the Stratus.

Hair-sparing technique using absorbable intradermal barbed suture versus traditional closure methods in supratentorial craniotomies for tumor.

BACKGROUND: Hair-sparing techniques in cranial neurosurgery have gained traction in recent years and previous studies have shown no difference in infection rates, yet limited data exists evaluating the specific closure techniques utilized during hair-sparing craniotomies. Therefore, it was the intention of this study to evaluate the rate of surgical site infections (SSIs) and perioperative complications associated with using an absorbable intradermal barbed suture for skin closure in hair-sparing supratentorial craniotomies for tumor in order to prove non-inferiority to traditional methods. METHODS: A retrospective review of supratentorial craniotomies for tumor by a single surgeon from 2011 to 2017 was performed. All perioperative adverse events and wound complications, defined as a postoperative infection, wound dehiscence, or CSF leak, were compared between three different groups: (1) hair shaving craniotomies + transdermal polypropylene suture/staples for scalp closure, (2) hair-sparing craniotomies + transdermal polypropylene suture/staples for scalp closure, and (3) hair-sparing craniotomies + absorbable intradermal barbed suture for scalp closure. RESULTS: Two hundred sixty-three patients underwent hair shaving + transdermal polypropylene suture/staples, 83 underwent hair sparing + transdermal polypropylene suture/staples, and 100 underwent hair sparing + absorbable intradermal barbed suture. Overall, 2.9% of patients experienced a perioperative complication and 4.3% developed a wound complication. In multivariable analysis, the use of a barbed suture for scalp closure and hair-sparing techniques was not predictive of any complication or 30-day readmission. Furthermore, the absorbable intradermal barbed suture cohort had the lowest overall rate of wound complications (4%). CONCLUSIONS: Hair-sparing techniques using absorbable intradermal barbed suture for scalp closure are safe and do not result in higher rates of infection, readmission, or reoperation when compared with traditional methods.

Predictors of Successful Discharge of Patients on Postoperative Day 1 After Craniotomy for Brain Tumor.

BACKGROUND: Shorter hospital stays have been associated with decreased complication rates, fewer hospital-acquired infections, and lower costs. We evaluated an optimized treatment paradigm for patients undergoing craniotomy allowing for postoperative day 1 (POD1) discharge if the criteria were met. We compared the complication and readmission rates between the POD1 patients and those with longer stays, and examined the patient and surgical variables for predictors of POD1 discharge. METHODS: We performed a retrospective review of craniotomies performed for tumor from 2011 to 2015. Craniotomies for tumors were included, and laser ablations and biopsies were excluded. RESULTS: A total 424 of patients were included, 132 (31%) of whom had been discharged on POD1. The mean length of stay was 6 days. The POD1 patients had had significantly better preoperative Karnofsky performance scale scores (P < 0.0001) and modified Rankin scale scores (P < 0.0001). Patient frailty, measured using the modified frailty index, was negatively predictive of POD1 discharge (P = 0.0183). Surgical factors predictive of early discharge were awake surgery (P < 0.0001) and supratentorial location (P < 0.0001). No POD1 patients experienced deep venous thrombosis (DVT), pulmonary embolus (PE), or urinary tract infections. However, of the patients with a length of stay >1 day, 4.4% and 2.7% developed DVT or PE (P = 0.0119) and urinary tract infections (P = 0.0202), respectively. Multivariate regression identified patient factors (male gender, low preoperative modified Rankin scale score), tumor factors (right-sided, supratentorial, smaller size), lower modified frailty index score, and operative factors (lack of a cerebrospinal fluid drain, awake surgery) as independent predictors of successful early discharge. CONCLUSIONS: Patients with good functional status can be safely discharged on POD1 after tumor craniotomy if the appropriate postoperative criteria have been met. Patients with early discharge had lower 30-day readmission and DVT/PE rates, likely owing to better baseline health status.