Older females in the workforce - the effects of age on psychophysical estimates of maximum acceptable lifting loads.

The number of older workers in the workforce is increasing substantially, and advanced age is associated with factors that could influence musculoskeletal injury risk and work capacity. This study's goals were to test whether psychophysical estimates of maximum acceptable weight of lift (liftmax) differed between younger and older workers, and to examine potential explanatory factors. Twenty-four female workers (half 50 + years; half 20-32 years) self-adjusted a box's mass to their perceived liftmax during four lifting tasks. Older workers' liftmax values were significantly lower (by approximately 24%) than their younger counterparts. There were no age-related differences in resting heart rate, or peak joint angles and final heart rate during the lifting trials. However, the older group demonstrated lower grip strength (by 24%), and lower heart rate reserve during the trials (by 18%). These results question whether current maximum acceptable lifting weights based on psychophysical information are appropriately protective for female workers greater than 50 years of age. Practitioner Summary: This psychophysical study demonstrated that older female workers (aged 50-63 years) selected maximum acceptable lift masses that were (on average) 24% lower than younger workers (aged 20-32 years), which corresponded with lower grip strength and heart rate reserve. Current maximum acceptable lifting weights based on psychophysical information may not protect female workers greater than 50 years of age.

Direct-from-specimen microbial growth inhibition spectrums under antibiotic exposure and comparison to conventional antimicrobial susceptibility testing.

Increasing global travel and changes in the environment may escalate the frequency of contact with a natural host carrying an infection and, therefore, increase our chances of encountering microorganisms previously unknown to humans. During an emergency, the etiology of infection may be unknown at the time of patient treatment. The existing local or global Antimicrobial Stewardship Programs may not be fully prepared for emerging/re-emerging infectious disease outbreaks, especially if they are caused by an unknown organism, engineered bioterrorist attack, or rapidly evolving superbug. We demonstrate an antimicrobial efficacy profiling method that can be performed in hours directly from clinical urine specimens. The antimicrobial potency was determined by the level of microbial growth inhibition and compared to conventional antimicrobial susceptibility testing results. The oligonucleotide probe pairs on the sensors were designed to target Gram-negative bacteria, specifically Enterobacterales and Pseudomonas aeruginosa. A pilot study of 10 remnant clinical specimens from the Clinical Laboratory Improvement Amendments-certified labs of New York-Presbyterian Queens was conducted, and only one sample was not detected by the probes. The remaining nine samples agreed with reference AST methods (Vitek and broth microdilution), resulting in 100% categorical agreement. In a separate feasibility study, we evaluated a dual-kinetic response approach, in which we inoculated two antibiotic stripwells containing the same antimicrobial concentrations with clinical specimens at the original concentration (1x) and at a 10-fold dilution (0.1x) to cover a broader range of microbiological responses. The combined categorical susceptibility reporting of 12 contrived urine specimens was 100% for ciprofloxacin, gentamicin, and meropenem over a range of microbial loads from 105 to 108 CFU/mL.

Real world clinical feasibility of direct-from-specimen antimicrobial susceptibility testing of clinical specimens with unknown microbial load or susceptibility.

Within healthcare settings, physicians use antibiograms, which offer information on local susceptibility rates, as an aid in selecting empirical antibiotic therapy and avoiding the prescription of potentially ineffective drugs. While antibiograms display susceptibility and resistance data at hospital, city, or region-specific levels and ultimately enable the initiation of antibiogram-based empirical antibiotic treatment, AST reports at the individual patient level and guides treatments away from broad-spectrum antibiotics towards narrower-spectrum antibiotics or the removal of antibiotics entirely. Despite these advantages, AST traditionally requires a 48- to 72-h turn-around; this window of time can be critical for some antimicrobial therapeutic interventions. Herein, we present a direct-from-specimen AST to reduce the time between patient sampling and receipt of lab AST results. The biggest challenge of performing AST directly from unprocessed clinical specimens with an unknown microbial load is aligning the categorical susceptibility report with CLSI reference methods, which start from a fixed inoculum of 0.5 McFarland units prepared using colonies from a sub-culture. In this pilot clinical feasibility study using de-identified remnant specimens collected from MCW, we observed the high and low ends of microbial loads, demonstrating a final categorical agreement of 87.5% for ampicillin, 100% for ciprofloxacin, and 100% for sulfamethoxazole-trimethoprim.

Method for concentrating viable microorganisms for microbial load determination and eliminating uncertainty from matrix effects from urine and whole blood.

The ability to assess and eliminate the matrix effect in bioanalytical methods is critical for reproducibility, but sample preparation procedures necessary to address the matrix effect for microbiological methods could be significantly different if viable pathogens are required for downstream microbiological response analysis. A pure bacterial culture remains essential for virulence, antibiotic susceptibility, and phenotypic response studies in order to facilitate the understanding and treatment of caused diseases. Bacterial culture involves the collection, inoculation, incubation, growth, and detection of viable organisms while avoiding contamination throughout the entire process. The goal of this method is to concentrate viable pathogens directly from clinical specimens such as whole blood and urine while removing most interfering matrix components through pelleting in an enriched media, which is designed to facilitate the growth of clinically relevant microorganisms. Nonselective culture media with no inhibitors is used to permit the growth of most of the microorganisms present in the clinical samples studied. Most of the species implicated in clinical infections are mesophilic bacterial species, so the pelleting procedure is conducted at medium temperatures of 37°C to facilitate optimal growth.•Viable bacterial pelleting for phenotypic response analysis.•Concentration of bacteria by centrifugation and matrix component removal for direct-from-specimen molecular analysis.•Viable pathogen recovery directly from whole blood and urine.

Phenotypic microbial response to antimicrobial exposure conditions with a molecular analysis quantification of species-specific 16S rRNA content.

The emergence and rapid spread of resistant bacteria has become a serious public health concern worldwide. Delayed antimicrobial therapy significantly increases mortality in high-risk infections with a particularly strong association with septic shock. Therefore, antimicrobial agents are often injudiciously used without any evidence-based microbiological confirmation. Antimicrobial consumption is strongly linked to the emergence and dissemination of antimicrobial-resistant bacteria strains in several epidemiological studies. According to CDC's recent publication, an estimated 30% of outpatient oral antimicrobial prescriptions may have been inappropriate. A compact and rapid pathogen identification (ID) and antimicrobial susceptibility testing (AST) can assist to address both the unnecessary use and overuse of antimicrobials, and therefore effectively reduce antimicrobial resistance. The overall goal of these AST protocols is to deliver a molecular diagnostic platform that is capable of profiling the antimicrobial susceptibility of causative pathogens in hours, not days. The presented AST utilizes an electrochemical sensor to quantify the microbial changes of 16S rRNA after exposure to various antimicrobial conditions either from clinical isolates or directly from unprocessed clinical specimens such as urine and blood. These protocols can be performed by our robotic lab automation systems or manual benchtop assays with associated reagent kits, AST stripwells and sensor chips.•A rapid, quantifiable antimicrobial efficacy profiling comparable to traditional AST reporting.•Customized antimicrobials and dilution ranges tailored to unique specifications for research and development.•Direct antimicrobial susceptibility of viable pathogen from whole blood, urine, or subculture.

Rapid Electrochemical-Based PCR-Less Microbial Quantification and Antimicrobial Susceptibility Profiling Directly From Blood and Urine With Unknown Microbial Load or Species.

Novel molecular platforms are available for identifying (ID) the causative agents of microbial infections and generating antimicrobial susceptibility testing (AST) profiles, which can inform the suitable course of treatment. Many methods claim to perform AST in minutes or hours, often ignoring the need for time-consuming steps such as enrichment cultures and isolation of pure cultures. In clinical microbiology laboratories, an infectious microbial must first be cultured (overnight to days) and identified at the species level, followed by a subsequent AST with an additional turnaround time of 12-48 h due to the need for regrowth of the organism in the absence and presence of relevant antibiotics. Here, we present an electrochemical-based direct-from-specimen ID/AST method for reporting directly from unprocessed urine and blood in hours. In a limit of detection study of 0.5-ml whole blood samples for point-of-care and pediatric applications, 16.7% (4/24) of samples contrived at 2 CFU/ml and 100% (24/24) of samples contrived at 6 CFU/ml were reported positive in 6.5 h, indicating a limit of detection of 6 CFU/ml. In a separate direct-from-specimen AST study, the categorical susceptibility was reported correctly for blinded susceptible, intermediate, resistant, and polymicrobial contrived specimens in 4 h.

Categorizing microbial growth inhibition through quantification of 16S rRNA growth marker with stripwells covering a spectrum of antimicrobial conditions.

Culture-based microdilution and disk diffusion tests are two commonly used reference methods for determining the susceptibility of causative bacteria to antibiotics. However, these methods are slow and laborious. Automated antimicrobial susceptibility test (AST) instruments are extensively used in clinical microbiology labs, replacing manual methods to perform gold standard microdilution or disk diffusion methods. These automated instruments require the use of isolated bacteria grown in pure culture against a fixed antimicrobial panel, and the susceptibility tests are based on measuring bacterial growth or turbidity changes over a range of pre-determined antimicrobial conditions. As a result, these automated technologies remain inherently inflexible to frequent adjustment of minimum inhibitory concentrations published by the Clinical and Laboratory Standards Institute and are limited by the detection methods that consumables were designed for. Here, we present a stripwell that is compatible with the 96-well format of most lab automation systems to provide a streamlined workflow to inoculate microorganisms for a customized or routine AST. The main goal of this method of stripwell preparation with various antibiotic conditions is to enable the utility of lab automation for phenotypic antibiotic response assays to address the reproducibility issues due to manual operation. • A standardized and scalable solution from inoculation to antimicrobial incubation • Microplates in stripwell format offer the advantage of greater flexibility in clinical microbiology and diagnostics • Customized antimicrobials and dilution ranges tailored to unique specifications for research and development.

Corrigendum to "Categorizing microbial growth inhibition through quantification of 16S rRNA growth marker with stripwells covering a spectrum of antimicrobial conditions" [MethodsX 8 (2021) 101453].

[This corrects the article DOI: 10.1016/j.mex.2021.101453.].

Transportation protocols for accurate assessment of microbial burden classification using molecular methods.

Point-of-care testing is cost-effective, rapid, and could assist in avoiding hospital visits during a pandemic. However, they present some significant risks that current technologies cannot fully address. Skin flora contamination and insufficient specimen volume are two major limitations preventing self-collection microbiological testing outside of hospital settings. We are developing a hybrid testing procedure to bridge the laboratory test with patient-side specimen collection and transportation for molecular microbial classification of causative bacterial infection and early identification of microbial susceptibility profiles directly from whole blood or urine specimens collected patient-side by health care workers such as phlebotomists in nursing homes or family clinics. This feasibility study presents our initial development efforts, in which we tested various transportation conditions (tubes, temperature, duration) for direct-from-specimen viable pathogen detection to determine the ideal conditions that allowed for differentiation between contaminant and causative bacteria in urine specimens and optimal growth for low-concentration blood specimens after transportation. For direct-from-urine assays, the viable pathogen at the clinical cutoff of 105 CFU/mL was detected after transportation with molecular assays while contaminants (≤ 104 CFU/mL) were not. For direct-from-blood assays, contrived blood samples as low as 0.8 CFU/mL were reported positive after transportation without the need for blood culture.

Feasibility and potential significance of rapid in vitro qualitative phenotypic antimicrobial susceptibility testing of gram-negative bacilli with the ProMax system.

The emergence and evolution of antibiotic resistance has been accelerated due to the widespread use of antibiotics and a lack of timely diagnostic tests that guide therapeutic treatment with adequate sensitivity, specificity, and antimicrobial susceptibility testing (AST) accuracy. Automated AST instruments are extensively used in clinical microbiology labs and provide a streamlined workflow, simplifying susceptibility testing for pathogenic bacteria isolated from clinical samples. Although currently used commercial systems such as the Vitek2 and BD Phoenix can deliver results in substantially less time than conventional methods, their dependence on traditional AST inoculum concentrations and optical detection limit their speed somewhat. Herein, we describe the GeneFluidics ProMax lab automation system intended for a rapid 3.5-hour molecular AST from clinical isolates. The detection method described utilizes a higher starting inoculum concentration and automated molecular quantification of species-specific 16S rRNA through the use of an electrochemical sensor to assess microbiological responses to antibiotic exposure. A panel of clinical isolates consisting of species of gram-negative rods from the CDC AR bank and two hospitals, New York-Presbyterian Queens and Medical College of Wisconsin, were evaluated against ciprofloxacin, gentamicin, and meropenem in a series of reproducibility and clinical studies. The categorical agreement and reproducibility for Citrobacter freundii, Enterobacter cloacae, Escherichia coli, Klebsiella aerogenes, Klebsiella oxytoca, Klebsiella pneumoniae, and Pseudomonas aeruginosa were 100% and 100% for ciprofloxacin, 98.7% and 100% for gentamicin and 98.5% and 98.5% for meropenem, respectively.