View abstract Objective:We report a case of cefazolin-induced coagulopathy in a patient with a methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia.Setting:Medical intensive care unit at a 1,500-bed, tertiary medical center.Design:A 74-year-old male presented to the medical intensive care unit with septic shock secondary to a left skin and soft tissue infection. Blood cultures resulted positive for and the patient was initiated on cefazolin therapy. Shortly after initiation of therapy, patient lab work showed an increased INR to a max of >9.67. Hematology was consulted, and further work-up revealed a clotting deficiency consistent with a vitamin K-mediated coagulopathy. Intravenous vitamin K was administered, and the patient had rapid correction of their INR. Therapy was switched to oxacillin for the completion of treatment with no further cases of coagulopathy.Conclusion:Cefazolin-associated coagulopathy, though rare, should be considered in patients with unexplained INR elevation during therapy. Early recognition is critical, as discontinuation of the offending agent and administration of vitamin K can rapidly reverse coagulopathy. Clinicians should maintain heightened awareness in critically ill patients, particularly when additional risk factors for coagulopathy are present.

View abstract Objective:To describe antibiotic use and clinical outcomes in hospitalized patients with gram-positive bacteremia based on penicillin (PCN) allergy status.Design:Retrospective cohort study.Participants:3,162 patients admitted to acute Veterans Health Administration facilities between January 2021 and December 2022 with ≥1 blood culture positive for methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-susceptible Staphylococcus lugdunensis (MSSL), ampicillin-susceptible Enterococcus faecalis (ASEF), Streptococcus pneumoniae (Spne), or Streptococcus pyogenes.Methods:Calculated the prevalence ratio (PR) to determine the association, if any, between the PCN allergy label and ≥1 day alternate antibiotic use, completion of ≥50% of targeted therapy with alternate, resistant gram-positive infection (RGPI), and broad-spectrum hospital-onset infection (BSHOI) antibiotics, 7-day acute kidney injury (AKI), 60-day Clostridioides difficile infection, hospital length of stay, 90-day recurrence, and 90-day mortality.Results:Patients with ASEF and Spne bacteremia with a PCN allergy had higher rates of ≥1 day of alternate antibiotic use (ASEF PR 1.21 [95% CI 1.08–1.35]; Spne 1.73 [1.25–2.38]) and completing ≥50% of targeted therapy with an alternate antibiotic (ASEF 5.60 [4.22–7.42]; Spne 4.10 [1.93–8.69]). Additionally, in the ASEF bacteremia group, PCN allergy status was associated with higher rates of completing ≥50% of targeted therapy with RGPI (5.52 [4.17–7.31]) and BSHOI (2.04 [1.10–3.78]) antibiotics. Patients with MSSA/MSSL bacteremia with a PCN allergy had higher 90-day recurrence (3.68 [1.02–13.28]) and, if predominantly using vancomycin instead of cefazolin, 7-day AKI (4.48 [1.44–13.98]).Conclusions:Our findings highlight opportunities for optimizing antibiotic selection and clinical outcomes among PCN-allergic patients with MSSA/MSSL, ASEF, and Spne bacteremia.

Trends in Staphylococcus aureus bacteremia (SAB) mortality in the United States, including the impact of coronavirus disease 2019, have not been well described.MethodsActive, laboratory- and population-based surveillance data from 20 counties (7 states) were used to examine annual, 30-day mortality rates among US adult patients with methicillin-resistant and methicillin-susceptible Staphylococcus aureus (MRSA and MSSA, respectively) bacteremia during 2005–2022. Medical records and state vital statistics data were linked to ascertain death. Multivariable survival analysis estimated the association between recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (a positive SARS-CoV-2 test of ≤30 days before incident culture) and mortality among SAB cases, adjusting for other risk factors. Analyses were stratified by MRSA/MSSA and epidemiologic class (hospital-onset [HO], healthcare-associated community-onset [HACO], and community-associated [CA]).ResultsOverall, SAB mortality was 21%. Annual SAB mortality rates were generally stable prepandemic before increasing by 33% and 41% among HO MRSA and MSSA cases, respectively, and by 49% among CA MRSA cases, but not among HACO or MSSA CA cases, from 2019 through 2021. Among HO cases with recent SARS-CoV-2 infection, annual mortality rates were as high as 75%. Adjusted hazard ratios for recent SARS-CoV-2 infection ranged from 1.9 (95% confidence interval: 1.5–2.3) (HACO MRSA) to 3.0 (95% confidence interval: 2.4–3.7) (HO MSSA).ConclusionsRecent SARS-CoV-2 infection was a significant risk factor for death among patients with SAB during 2020–2022. Strengthening infection prevention efforts in similar respiratory pandemics in the future could help prevent increases in SAB mortality rates.

Cephalexin is increasingly used as initial and oral transition therapy for severe infections, but optimal dosing in this setting remains uncertain.MethodsFour cephalexin pharmacokinetic (PK) datasets spanning preterm neonates through young adults were pooled to develop a unified population PK model. Simulations estimated probability of target attainment (PTA) and cumulative fractional response (CFR, target attainment weighted across the pathogen MIC distribution) across fT>MIC targets (free drug time above the minimum inhibitory concentration), MIC distributions for methicillin-susceptible Staphylococcus aureus (MSSA) and Enterobacterales, and multiple dosing regimens.ResultsSeventy-one subjects (age 9 days-29 years) contributed 360 plasma samples, best described by a one-compartment model with first-order absorption and lag time. Apparent volume and clearance scaled with fat-free mass, and clearance increased with post-menstrual age. Absorption was slower in neonates. Cephalexin 25 mg/kg/dose, maximum 1,000 mg, every 8 hours achieved 1-log kill targets for MSSA (PTA ≥98% for 35% fT>MIC at MIC = 4 mg/L); every 6-hour dosing was needed at MIC = 8 mg/L. For Enterobacterales, a 60% fT>MIC target was achieved only in infants <2 months. However, higher-dose regimens (37.5-50 mg/kg, maximum 1,500 mg, every 6 hours) achieved CFRs >90% for 40-50% fT>MIC targets when cefazolin MICs were ≤2 mg/L.ConclusionsCephalexin PK varies with age but is well-captured by a unified size- and maturation-scaled model. These data support dosing within the FDA-approved range for systemic MSSA infections. Higher-dose regimens are necessary for adequate target attainment against Enterobacterales. Appropriately dosed cephalexin represents a viable option for selected severe infections, including oral transition therapy.

GCF and MSSA Sign MoU to Advance NTN Certification and Interoperability

Methicillin-susceptible Staphylococcus aureus (MSSA) remains a major cause of morbidity and mortality worldwide, particularly owing to its role in complicated infections including bloodstream infectio...

Cefazolin is non-inferior to flucloxacillin in the treatment of MSSA bacteremia and is associated with less AKI.

Due to the high sensitivity rates found in this study, delafloxacin may be considered as a good therapeutic option for the treatment of S. aureus infections, including MRSA, particularly in skin and soft...

Adults with SAB experience higher 30-day mortality rates when accompanied by recent SARS-CoV-2 infection.

This case underscores that during influenza seasons, early empirical anti-staphylococcal therapy should be considered in children with rapidly progressive pneumonia and shock, even when CA-MSSA is suspected....

A fluorimeter the size of an AirPod case replicates gold-standard lab assays and can deliver portable diagnostic testing for Staph infection, HIV, cancer, and more.

A randomized trial finds cefazolin offers similar efficacy and less acute kidney injury than cloxacillin or flucloxacillin in adults with bacteremia.

Este reporte de caso clínico documenta a una niña de 8 años que desarrolló de forma inusual microangiopatía trombótica (TMA) y glomerulonefritis aguda tras presentar impétigo por Staphylococcus aureus sensible a la meticilina (MSSA). Se detalla el manejo terapéutico mediante cefazolina y restricción de líquidos, la identificación de las toxinas exfoliativas B (etb) y alfa-hemolisina (hla) en la cepa bacteriana, y la recuperación clínica y de laboratorio completa de la paciente a los 84 días de seguimiento.

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This novel assay for the detection of staphylococcal beta-lactamase demonstrated simplicity, rapidity and excellent accuracy after 24 h incubation (100% sensitivity and specificity) across a genetically...