Isolation and Characterization of a Novel Alpha-Hemolytic Streptococcus spp. from the Oral Cavity and Blood of Septicemic Periparturient Immunodeficient Mice.

MISTRG is an immunodeficient mouse strain that expresses multiple human cytokines that support hematopoietic stem cell maintenance and myelopoiesis. While establishing a breeding colony of MISTRG mice in a dedicated barrier room, 6 cases of death or disease occurred in pregnant or postpartum mice. Clinically, this manifested as hunched posture, dyspnea, and 1 case of emaciation with ataxia. Pathologic analysis of 7 mice revealed multisystemic necrosuppurative inflammation variably affecting the uterus and placenta, joints, meninges, inner and middle ears, kidneys, and small intestine. Bacteria cultured from the blood of septic mice were identified with 89% probability by the Vitek 2 identification system as Streptococcus sanguinus with atypical biochemical parameters; the API 20E/NE system fully differentiated the isolates as a novel Streptococcus species. MALDI Biotyper-based mass spectrometry also indicated that the phenotype represented a novel Streptococcus spp. Sequencing revealed that the full-length 16S rRNA gene identity was below 97% with known Streptococcus species, including the 2 closest species Streptococcus acidominimus and Streptococcus azizii. We propose the name Streptococcus murisepticum spp. nov to our novel isolates. All male mice in this colony remained healthy despite their association with diseased female mice. Overall, 19% of the colony carried the novel Streptococcus in their oral cavity, but it could not be detected in feces. The organism was sensitive to amoxicillin, which was administered via drinking water throughout pregnancy and weaning to establish a colony of pathogen-negative future breeders. The colony remained disease-free and culture-negative for Streptococcus murisepticum spp. nov after treatment with amoxicillin. We suspect that oral colonization of MISTRG mice with the novel Streptococcus species and its associated unique pathology in periparturient mice is potentially the principal cause of loss of this strain at several institutions. Therefore, screening the oral cavity for α-hemolytic streptococci followed by targeted antibiotic treatment may be necessary when establishing MISTRG and allied immunodeficient mouse strains.

Risk-based Decision Making Definition: A Scoping Review of Food, Agricultural, Environmental, and Medical Literature.

Risk-based decision making (RBDM) is a term that is used frequently as an aspirational goal in many fields, including health, engineering, environmental science, regulatory and, more recently, food safety. When RBDM is used in the literature, many different types of criteria are used to characterize a decision process as being "risk-based." Like the parable about the blind men and the elephant, everyone is confident they know what RBDM means even though there is no universal definition. The use of RBDM is gaining wide acceptance and implies a level of rigor and focus that many decisionmakers and stakeholders are interested in adopting. However, without one clear definition, there are questions about what a RBDM approach really means. This study summarizes peer-reviewed and gray literature that uses the term "RBDM" from the last 50 years in the agricultural, environmental, and medical areas. The criteria discussed were identified and organized into themes. A foundational definition is proposed to represent the most fundamental use of RBDM in the literature, and three themes covering the additional concepts presented in some of the literature were identified and added as themes within the definition. Results from this research will inform practitioners interested in following the principles of RBDM, and will help guide researchers who are interested in advancing this approach. The most immediate use will be to guide the development of a roadmap for a risk-based food safety system for low- and middle-income countries and to aid the global food safety community in moving toward RBDM.

The incidence and effect of fatty atrophy, positive tangent sign, and rotator cuff tears on outcomes after total shoulder arthroplasty.

BACKGROUND: Treatment choices for total shoulder arthroplasty (TSA) in the absence of full-thickness rotator cuff tears (RCTs) are not clearly defined in current literature. This study investigated the prevalence and effect of preoperative partial-thickness RCTs and muscular degenerative changes on postoperative outcomes after TSA. METHODS: Medical records and magnetic resonance imaging studies were reviewed for patients who underwent TSA for primary glenohumeral osteoarthritis with minimum 2-year follow-up to determine preoperative tear classification, Goutallier grade, and supraspinatus tangent sign. Postoperative pain on the visual analog scale, range of motion, and patient outcomes scores were obtained to correlate preoperative RCT status, Goutallier grading, tangent sign, and postoperative outcomes. Patients with full-thickness RCT on preoperative magnetic resonance imaging were excluded. RESULTS: Forty-five patients met all inclusion criteria (average age, 65 ± 10 years; average follow-up, 43 months). Of the patients undergoing TSA, 40% had a significant (>50% thickness) partial RCT. Grade 3 to 4 Goutallier changes were noted in 22% of all patients, and 13% demonstrated grade 3 to 4 changes in the context of no tear. Positive tangent sign was present in 7% of all patients. The preoperative Goutallier grade of the infraspinatus was significantly negatively correlated with postoperative forward elevation (P = .02) and external rotation (P = .05), but rotator cuff pathology, including tear status, Goutallier grade, and the presence of a tangent sign, did not correlate with postoperative functional outcome scores. CONCLUSIONS: Even in the absence of a full-thickness RCT, rotator cuff atrophy, fatty infiltration, and partial thickness tearing are common findings. Although postoperative range of motion is correlated to Goutallier changes of the infraspinatus, rotator cuff pathology is not correlated to outcomes after TSA; therefore, one may proceed with TSA without concern of their effect on postoperative outcomes.

Resilience correlates with outcomes after total shoulder arthroplasty.

BACKGROUND: Resilience, characterized by an ability to bounce back or recover from stress, is increasingly recognized as a psychometric property affecting many outcomes' domains including quality of life, suicide risk in active-duty military personnel, and recovery in cancer patients. This study examines the correlation between resilience, as measured by the Brief Resilience Scale (BRS), and traditional outcome scores including the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and Penn scores in patients undergoing total shoulder arthroplasty (TSA). METHODS: Seventy patients undergoing primary anatomic TSA were followed up for a minimum of 2 years (mean, 30 ± 3 months). Patients were stratified into groups a priori, based on deviation from the mean of the BRS score, into low-resilience (LR), normal-resilience (NR), and high-resilience (HR) patients, and outcome scores were calculated for each group. RESULTS: Postoperative BRS scores significantly correlated with ASES, Penn, and SANE scores (r = 0.41-0.44, P < .004 for all scores). When we evaluated patients based on resilience group, the LR group had a Penn score that was 34 points lower than that in the HR group. Likewise, the LR group had a SANE score that averaged 40 points lower than that in the HR group (SANE score of 53 points in LR group and 92 points in HR group, P = .05). When we evaluated ASES subscores, it appeared that the pain subscale was responsible for most of the difference between the LR and HR groups (29 points and 48 points [out of 50 points], respectively; P = .03). CONCLUSIONS: Resilience is a major predictor of postoperative outcomes after TSA. Patients who are classified as having LR have outcome scores that are 30 to 40 points lower on traditional outcome scales than patients with HR.