Pediatric Facial Fracture Associated Craniofacial and Cervical Spine Injury.

Management of pediatric facial fractures depends on location and severity, age, and associated injuries. Accurate diagnosis of associated injuries is crucial for effective treatment. This study evaluates the incidence of associated injuries and seeks to determine the influencing factors to provide imaging guidance. A retrospective review of pediatric facial fractures from the American College of Surgeons National Trauma Data Bank from 2017 to 2021 was completed. Associated cervical spine (c-spine), skull fracture, traumatic brain injury (TBI), and intracranial bleeding were evaluated. Demographics, fracture patterns, mechanisms, protective devices, and the Glasgow Coma Scale (GCS) were reviewed. A total of 44,781 pediatric patients with 65,613 facial fractures were identified. Of the total, 5.47% had a c-spine injury, 21.86% had a skull fracture, 18.82% had TBI, and 5.76% had intracranial bleeding. Multiple fractures significantly increased the rate of all associated cranial and c-spine injuries. Single midface fractures had the highest c-spine, TBI, and intracranial bleeding rates. With increasing age, there was a significant increase in c-spine injury and TBI, while there was a decrease in skull fractures. Motor vehicle accidents and GCS <13 were associated with significantly increased rates of all injuries. Among pediatric patients with facial fractures, 5.47% had a c-spine injury, 21.86% had a skull fracture, 18.82% had TBI, and 5.76% had intracranial bleeding. The authors' findings recommend c-spine imaging in older age and cranial imaging in younger patients. Multiple facial fractures, fractures of the midface, decreased GCS, and motor vehicle accidents increase the need for both c-spine and cranial imaging.

Pediatric Tissue Expansion: Analysis of the National Surgical Quality Improvement Program-Pediatric.

INTRODUCTION: Tissue expansion (TE) in pediatric surgery provides vascularized tissue to attain functional and esthetic goals in a broad range of reconstructive procedures. Our study evaluates the demographic, operative, and short-term outcomes of TE in pediatric patients utilizing the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database and highlights factors associated with postoperative complications. MATERIALS AND METHODS: Retrospective review of a large multicenter database of 402 pediatric patients that underwent TE within the NSQIP-P database from 2013 to 2020 at freestanding general acute care children's hospitals, children's hospitals within a larger hospital, specialty children's hospitals, or general acute care hospitals with a pediatric wing. Patient demographics, clinical risk factors, operative information, and postoperative outcomes were collected with an odds ratio analysis of risk factors. RESULTS: Patients were majority female (55.5%), White (63.2%), and non-Hispanic (67.4%). The minority were born prematurely (11.9%) and had congenital malformations (16.7%). Complications occurred in 5.7%, unplanned readmission in 4.5%, and unplanned operation in 6.5% of patients. Complications lead to readmission in 2.5% and return to the operating room in 3.2% of patients. American Society of Anesthesiology (ASA) score III-IV, congenital malformations, >1-day hospital stay, and pulmonary, neurologic, and hematologic comorbidities were associated with the greatest increase in odds of complication. CONCLUSION: This study utilizes the NSQIP-P to provide a comprehensive multicenter view of pediatric patients undergoing TE. Increased understanding of risk factors for complications allows for guidance in patient selection and helps in achieving favorable surgical outcomes.

Three-dimensional Anthropometric Analysis of Racial and Ethnic Differences in Unilateral and Bilateral Cleft Nasal Deformity.

This study used three-dimensional measurements to provide a nasolabial analysis of patients with unilateral cleft lip and palate (UCLP), bilateral cleft lip and palate (BCLP), and controls across different races and ethnicities.A retrospective comparative study.Tertiary care pediatric institution.The study included 90 patients with UCLP, 43 patients with BCLP, and 90 matched controls. Patients are separated as self-identified Caucasian, Hispanic, or African American.Nasal length, nasal protrusion, columellar height, columellar width, tip width, alar width, alar base width, nasolabial angle, upper lip length, philtrum length, nostril height, and nostril width.All UCLP groups had significantly greater columella and tip widths and decreased nasolabial angles than controls. All BCLP groups had significantly greater columella width, tip width, nasolabial angle, and nostril widths. Upper lip length, philtrum length, and nostril height were significantly decreased in BCLP compared to controls. Across UCLP groups, African Americans had significantly decreased nasal protrusion and columella height and a significantly increased columella width compared to Caucasians and Hispanics. Alar and alar base widths were significantly different between all groups. Across BCLP groups, the Caucasian nostril width was significantly less than the African Americans.These findings suggest that when correcting nasolabial characteristics in patients with cleft lip, it is important to consider racial and ethnic differences to achieve a normal appearance. Specifically, goals for alar width, alar base width, nasal tip, and projection should be tailored to the patient's race and ethnicity.

Open Versus Minimally Invasive Approach for Craniosynostosis: Analysis of the National Surgical Quality Improvement Program-Pediatric.

OBJECTIVE: This multicenter study aimed to compare demographic, operative, and short-term outcomes data between open and minimally invasive surgical approaches for craniosynostosis repair utilizing the American College of Surgeon's National Surgical Quality Improvement Program Pediatric (NSQIP-P) database and highlight surgical disparities among races and ethnicities. DESIGN: Retrospective review of large multicenter database. SETTING: Freestanding general acute care children's hospitals, children's hospitals within a larger hospital, specialty children's hospitals, or general acute care hospitals with a pediatric wing. PATIENTS AND PARTICIPANTS: A total of 4931 pediatric patients underwent craniosynostosis correction within the NSQIP-P database from 2013 to 2019. INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): Demographic information included age at surgery, sex, race, and ethnicity. Operative and outcomes measures included operative time, anesthesia time, days until discharge, postoperative complications, blood transfusions, 30-day readmission, and 30-day unplanned return to operating room. RESULTS: Patients who underwent minimally invasive surgery had significantly shorter operative and anesthesia times (p < .001; p < .001), fewer days until discharge (p < .001), fewer postoperative complications (p < .05), and less blood transfusions (p < .001). The proportion of White patients was significantly higher in the minimally invasive surgery group (p < .01), whereas Black and Hispanic patients had a significantly higher proportion in the open surgery group (p < .001; p < .001). Additionally, the percentage of patients undergoing minimally invasive surgery increased from 3.8% in 2014 to over 13% in 2019. CONCLUSIONS: This study adds to a growing consensus that minimally invasive surgery has significantly decreased operative time, anesthesia time, transfusion rates, length of hospital stay, and postoperative complications compared to open surgery. Racial and ethnic surgical disparities showed larger proportions of Black and Hispanic populations undergoing open procedures.

Three-dimensional Analysis of Facial Asymmetry in Unilateral Lambdoid Craniosynostosis.

OBJECTIVE: Unilateral lambdoid synostosis (ULS) is characterized by occipital flattening, mastoid bulging, and contralateral parietal bossing. Anterior craniofacial features are less well-defined. This study utilizes volumetric, craniometric, and composite heat maps of three-dimensional (3D) rendered CT scans to analyze anterior craniofacial asymmetry in ULS and compared to controls. DESIGN: A retrospective review of three-dimensional CT scans. SETTING: Tertiary care pediatric institution. PATIENTS, PARTICIPANTS: 30 ULS and 30 control patients. MAIN OUTCOME MEASURE(S): Volumetric and craniometric analysis of the anterior fossa, orbits, zygomas, maxilla, and mandible was performed. RESULTS: The anterior fossa volume was greater bilaterally (0.047, 0.038), and the fossa angle was more anterior contralaterally (<0.001) and more anterior bilaterally than controls (0.038, 0.033). The orbits had greater height and lesser depth bilaterally compared to controls (0.006, 0.009; < 0.001, < 0.001). Zygoma length was significantly greater on the contralateral side than controls (0.048; < 0.001). Nasal contralateral deviation of 3.57 ± 1.97°. The maxillary length was longer on the contralateral side (0.045). The mandibular angle was more anterior on the ipsilateral side and posterior on the contralateral side (<0.001) compared to controls (0.042, < 0.001). Chin had a contralateral deviation of 1.04 ± 3.74°. CONCLUSIONS: ULS has significant asymmetry in the anterior craniofacial skeleton. There is a bilateral expansion of the anterior cranial fossa with greater frontal bossing on the contralateral side. Increased orbital height and decreased depth. Contralateral zygomatic and mandibular body lengthening with posterior mandibular deviation. These features may provide more effective diagnosis and potential clinical management strategies.

Alar Asymmetry in Patients with Unilateral Cleft Lip: Implications for Secondary Rhinoplasty.

OBJECTIVE: Alar asymmetry in unilateral cleft lip (UCL) nasal deformity is a well-recognized clinical feature. However, there is a lack of comprehensive quantitative analysis of this asymmetry. This study compares the shape, volume, and axis rotation between the cleft and non-cleft ala in skeletally mature patients with UCL. DESIGN: A retrospective comparative study utilizing three-dimensional rendered CT scans. SETTING: Tertiary care pediatric institution. PATIENTS, PARTICIPANTS: This study included 18 patients with UCL nasal deformity at skeletal maturity. MAIN OUTCOME MEASURE(S): Cleft and non-cleft side ala volume, surface area, and axis to the midsagittal plane. RESULTS: The cleft-side ala was significantly lesser in volume by 27.3%, significantly lesser in surface area by 17.6%, and significantly greater in surface area to volume ratio by 14.6% than the non-cleft ala. The cleft-side ala was significantly greater by 43.1% horizontal axis to the midsagittal plane. In patients with primary rhinoplasty, the cleft-side ala had 28.0% less volume and 18.7% less surface area. In intermediate rhinoplasty, the cleft-side ala had 39.1% less volume and 23.5% less surface area than the non-cleft ala. CONCLUSIONS: Significant asymmetry exists between the cleft-side and non-cleft ala in patients with UCL. The cleft-side ala is significantly smaller in volume and surface area than the non-cleft ala. Additionally, the cleft-side ala demonstrates a significantly greater horizontal axis that contributes considerably to nasal asymmetry, supporting the need to restore a normal vertical axis to the clef-side ala.

Reconstruction of Congenital Arhinia With Stereolithographic Modeling: Case Correlate and Literature Review.

Complete congenital arhinia is a rare defect of embryogenesis leading to the absence of the external nose and airway. We report our novel multistaged reconstructive approach and literature review. Nasal methyl methacrylate prosthesis was created from a stereolithographic model for use as a temporary prosthesis and tissue expander. Lefort 1 with cannulization was utilized for midface advancement and airway formation. External framework was reconstructed with bilateral conchal bowl cartilage and rib osteocartilagenous grafts. Patient was pleased with the aesthetics and had safe decannulation with the ability to breathe through the nose and airway.

Potential Complications With Cryopreserved Cadaveric Veins in Arteriovenous Loop Formation for Head and Neck Microvascular Reconstruction.

ABSTRACT: Vessel depletion in the head and neck from radiation or previous surgical intervention adds to the operative complexity by limiting reconstructive options. Arteriovenous (AV) loop vascular grafts provide a conduit to bypass these nonviable local vessels to provide adequate blood flow. In certain situations, autologous donor vascular options are deficient or not readily available for creation of the AV loop. Cadaveric vein grafts provide an alternative option in these circumstances, but the efficacy and safety has not yet been delineated. In this study we discuss our experience utilizing cryopreserved cadaveric vein grafts for AV loop creation in head and neck reconstruction. In our initial cohort we aim to elucidate potential challenges and complications associated with the use of cadaveric vein grafts.

Common Carotid-to-Internal Jugular Arteriovenous Loop for Single-Stage Microsurgical Reconstruction in the Radiated Vessel-Depleted Neck.

ABSTRACT: Management of head and neck defects in a radiated field can be quite challenging owing to the dearth of vasculature and significant degree of post-radiation fibrosis. In this setting, arteriovenous (AV) loop vascular grafts can bypass nonviable local vessels to provide viable and reliable inflow and outflow vessels for free tissue transfer in an otherwise hostile environment. Prior reports of the Corlett loop utilizing a cephalic vein transposition has been described however a common carotid-to-internal jugular AV loop has not been recently reported. Three patients underwent carotid artery to internal jugular vein AV loop creation to facilitate free-flap reconstruction secondary to radiation-induced vessel depletion. The specific technique described utilizes the saphenous vein as a donor and spares the cephalic vein for the possibility of flap complication. All three cases resulted in successful reconstruction, maintaining healthy tissue, vascular flow, and flap viability at all follow-up intervals. In our experience, vascular augmentation via AV loop formation provides reliable vascular inflow and outflow in the vessel-depleted neck to facilitate microvascular reconstruction. Sparing the cephalic vein yields an additional salvage mechanism in the event of venous congestion.

Three-Dimensional Analysis of Bilateral Cleft Lip and Palate Nasal Deformity.

OBJECTIVE: This cross-sectional study utilizes 3-dimensional analysis to assess nasal morphology in patients with bilateral cleft lip and palate (BCLP) compared to controls across the timeline of cleft care. DESIGN: Retrospective comparative cross-sectional study. SETTING: Tertiary pediatric academic institution. PATIENTS AND PARTICIPANTS: One hundred and twelve patients with BCLP and an equal number of age and sex-matched control participants. MAIN OUTCOME MEASURE(S): Nasolabial angle, nasal length, nasal protrusion, columella length, columella width, nasal tip width, alar width, and alar base width were collected at each time point. The measurements were collected pre-nasoalveolar molding (NAM) therapy, post-NAM therapy, post-primary cleft rhinoplasty, 1 year, 5 years, 10 years, and 15 years of age. RESULTS: Nasolabial angle and nasal tip width were significantly different from controls from pre-NAM through 15 years of age time points. Nasal length was not significantly different at any time point. Alar width and alar base width were significantly different from pre-NAM through 10 years of age time points. Nasal protrusion, columella length, and columella width were significantly different from pre-NAM through 5 years of age time points. CONCLUSIONS: This study demonstrates that three-dimensional photogrammetry is effective in assessing the changes in nasal morphology that occur throughout the course of care in patients with BCLP from before cleft lip repair to the completion of nasal growth.

Prophylactic Use of the Pectoralis Major Flap to Prevent Anastomotic Leak in the Reconstruction of a Total Laryngopharyngoesophagectomy Defect Combined With Gastric Pull-Up After Chemoradiotherapy.

Total laryngopharyngoesophagectomy defects after surgical ablation for laryngopharyngeal carcinoma with involvement of the cervical esophagus represents a challenge to the reconstructive surgeon. Complicating an already challenging operation is when surgical ablation occurs after failure of primary chemoradiation requiring the surgeon to operate and reconstruct in an irradiated field limiting potential reconstructive options. Due to the advanced stage at diagnosis, some studies have shown that while traditional management with radiotherapy may be considered as an initial treatment modality, often times this has failed to provide sustainable improvement in survival with reported high local recurrence rates. With relatively high local recurrence rates following radiotherapy, movement towards aggressive surgical resection is favored in some institutions. Despite this movement, primary treatment with chemoradiation is still commonly used as a primary modality opening up the opportunity for residual or recurrent disease leading the surgeon to perform salvage surgery to eradicate disease after primary treatment failure. With advanced ablative surgery comes the challenge to find an ideal reconstructive option that will optimize functional outcomes which has shown to be particularly challenging when operating in a post-radiated field with a higher risk for pharyngocutaneous fistulas. The authors present a case where reconstruction of such a defect after local failure with primary chemoradiation was successful using a single stage reconstruction with the gastric pull up technique in combination with a pectoralis major myocutaneous flap. As the risk of anastomotic leak is significantly higher in patients following radiation, this method showed utilizing a prophylactic muscle flap at the time of reconstruction may further bolster the repair and prevent anastomotic leak.

Tissue Modification in Nonsurgical Facelift Options.

Nonsurgical facelifts are a term for a heterogeneous group of procedures used by physicians to improve facial rejuvenation without the use of operative techniques. Patients demand these services due to the reduced recovery time and generally lower risk. However, nonsurgical techniques, to be effective, must induce conformational change in the cells and tissues of the face. Therefore, these techniques are significant procedures that have associated risks. Understanding the tissue modifications and mechanisms of action of these techniques is vital to their safe and effective use. The purpose of this article is to provide a background of tissue modification in nonsurgical facelift options.

Reconstruction of a subtotal septorhinectomy defect with a chimeric paramedian-pericranial forehead flap.

The nose is a complex structure important for aesthetic appearance, social interaction, and respiration. Full thickness nasal defects with resection of the septum pose a significant challenge to the reconstructive surgeon due to the lack of local tissues to replace the nasal lining and significant risk of nasal collapse owing to the paucity of rigid infrastructure. The purpose of this paper is to present a unique case of nasal reconstruction utilizing a bilaminar paramedian forehead flap (combined pericranial flap and forehead flap) with embedded cantilever rib graft in a patient who underwent resection for an intranasal malignancy involving the septum and soft tissue envelope. This case serves to demonstrate the great utility in using chimeric flaps based on a single pedicle given the low patient morbidity, predictable results, and rapid recovery period.

High-Resolution Melting Analysis for Rapid Detection of Sequence Type 131 Escherichia coli.

Escherichia coli isolates belonging to the sequence type 131 (ST131) clonal complex have been associated with the global distribution of fluoroquinolone and ß-lactam resistance. Whole-genome sequencing and multilocus sequence typing identify sequence type but are expensive when evaluating large numbers of samples. This study was designed to develop a cost-effective screening tool using high-resolution melting (HRM) analysis to differentiate ST131 from non-ST131 E. coli in large sample populations in the absence of sequence analysis. The method was optimized using DNA from 12 E. coli isolates. Singleplex PCR was performed using 10 ng of DNA, Type-it HRM buffer, and multilocus sequence typing primers and was followed by multiplex PCR. The amplicon sizes ranged from 630 to 737 bp. Melt temperature peaks were determined by performing HRM analysis at 0.1°C resolution from 50 to 95°C on a Rotor-Gene Q 5-plex HRM system. Derivative melt curves were compared between sequence types and analyzed by principal component analysis. A blinded study of 191 E. coli isolates of ST131 and unknown sequence types validated this methodology. This methodology returned 99.2% specificity (124 true negatives and 1 false positive) and 100% sensitivity (66 true positives and 0 false negatives). This HRM methodology distinguishes ST131 from non-ST131 E. coli without sequence analysis. The analysis can be accomplished in about 3 h in any laboratory with an HRM-capable instrument and principal component analysis software. Therefore, this assay is a fast and cost-effective alternative to sequencing-based ST131 identification.

IMP-27, a Unique Metallo-ß-Lactamase Identified in Geographically Distinct Isolates of Proteus mirabilis.

A novel metallo-ß-lactamase gene, blaIMP-27, was identified in unrelated Proteus mirabilis isolates from two geographically distinct locations in the United States. Both isolates harbor blaIMP-27 as part of the first gene cassette in a class 2 integron. Antimicrobial susceptibility testing indicated susceptibility to aztreonam, piperacillin-tazobactam, and ceftazidime but resistance to ertapenem. However, hydrolysis assays indicated that ceftazidime was a substrate for IMP-27.

Thirty-year Experience Treating Syndromic Craniosynostosis: Long-term Outcomes Following Cranial Expansions.

INTRODUCTION: Children with syndromic craniosynostosis require multiple cranial expansion procedures. The purpose of this study was to determine how many expansions are typically performed through maturity, to assess complication rates, and to identify trends that might reduce the burden of care. METHODS: A retrospective chart review was performed of all consecutive patients undergoing cranial vault enlargement procedures for syndromic craniosynostosis by a single surgeon. RESULTS: Of 444 patients treated with Apert or Crouzon/Pfeiffer syndromes, 348 had complete long-term records. The mean age at last follow up was 16.9 years. Initial cranial expansions were performed at a significantly younger age for those beginning care at outside centers: 7.7-months versus 25.7-months in Dallas. 26.4% had ventriculoperitoneal shunts (syndrome-specific incidences: Apert 16%, Crouzon 27%, Pfeiffer 54%). Of 498 procedures, 80% were anterior, 18% posterior, and 2% were mid-vaults. The overall complication rate was 2%, with no differences found between anterior and posterior procedures. Those treated solely in Dallas underwent a mean of 1.9 expansions. Children with Pfeiffer syndrome underwent more expansions (2.7) than those with Apert or Crouzon syndromes. Factors correlationing with more expansions included: earlier surgical interventions, use of distraction, venticuloperitoneal shunts, and treatment begun at outside centers (3.1 procedures). CONCLUSIONS: Children with syndromic craniosynostosis treated at a single center underwent an average of 2 skull expansion procedures with a 2% complication rate. Calvarial distraction, ventriculoperitoneal shunts, and earlier surgical interventions, were all associated with higher numbers of expansion procedures. Further research is needed to determine if these correlations are causal.

Nasal Airflow Dynamics following LeFort I Advancement in Cleft Nasal Deformities: A Retrospective Preliminary Study.

Unilateral cleft lip and palate (UCLP) nasal deformity impacts airflow patterns and pressure distribution, leading to nasal breathing difficulties. This study aims to create an integrated approach using computer-aided design (CAD) and computational fluid dynamics (CFD) to simulate airway function and assess outcomes in nasal deformities associated with unilateral cleft lip and palate (UCLP) after LeFort I osteotomy advancement. Significant alterations were observed in nasal geometry, airflow velocity, pressure dynamics, volumetric flow rate, and nasal resistance postoperatively, indicating improved nasal airflow. The cross-sectional area increased by 26.6%, airflow rate by 6.53%, and nasal resistance decreased by 6.23%. The study offers quantitative insights into the functional impacts of such surgical interventions, contributing to a deeper understanding of UCLP nasal deformity treatment and providing objective metrics for assessing surgical outcome.

The spread of pESI-mediated extended-spectrum cephalosporin resistance in Salmonella serovars-Infantis, Senftenberg, and Alachua isolated from food animal sources in the United States.

The goal of this study is to investigate the origin, prevalence, and evolution of the pESI megaplasmid in Salmonella isolated from animals, foods, and humans. We queried 510,097 Salmonella genomes under the National Center for Biotechnology Information (NCBI) Pathogen Detection (PD) database for the presence of potential sequences containing the pESI plasmid in animal, food, and environmental sources. The presence of the pESI megaplasmid was confirmed by using seven plasmid-specific markers (rdA, pilL, SogS, TrbA, ipf, ipr2 and IncFIB(pN55391)). The plasmid and chromosome phylogeny of these isolates was inferred from single nucleotide polymorphisms (SNPs). Our search resolved six Salmonella clusters carrying the pESI plasmid. Four were emergent Salmonella Infantis clusters, and one each belonged to serovar Senftenberg and Alachua. The Infantis cluster with a pESI plasmid carrying blaCTX-M-65 gene was the biggest of the four emergent Infantis clusters, with over 10,000 isolates. This cluster was first detected in South America and has since spread widely in United States. Over time the composition of pESI in United States has changed with the average number of resistance genes showing a decrease from 9 in 2014 to 5 in 2022, resulting from changes in gene content in two integrons present in the plasmid. A recent and emerging cluster of Senftenberg, which carries the blaCTX-M-65 gene and is primarily associated with turkey sources, was the second largest in the United States. SNP analysis showed that this cluster likely originated in North Carolina with the recent acquisition of the pESI plasmid. A single Alachua isolate from turkey was also found to carry the pESI plasmid containing blaCTX-M-65 gene. The study of the pESI plasmid, its evolution and mechanism of spread can help us in developing appropriate strategies for the prevention and further spread of this multi-drug resistant plasmid in Salmonella in poultry and humans.

Genomic analysis of azithromycin-resistant Salmonella from food animals at slaughter and processing, and retail meats, 2011-2021, United States.

IMPORTANCE: Macrolides of different ring sizes are critically important antimicrobials for human medicine and veterinary medicine, though the widely used 15-membered ring azithromycin in humans is not approved for use in veterinary medicine. We document here the emergence of azithromycin-resistant Salmonella among the NARMS culture collections between 2011 and 2021 in food animals and retail meats, some with co-resistance to ceftriaxone or decreased susceptibility to ciprofloxacin. We also provide insights into the underlying genetic mechanisms and genomic contexts, including the first report of a novel combination of azithromycin resistance determinants and the characterization of multidrug-resistant plasmids. Further, we highlight the emergence of a multidrug-resistant Salmonella Newport clone in food animals (mainly cattle) with both azithromycin resistance and decreased susceptibility to ciprofloxacin. These findings contribute to a better understating of azithromycin resistance mechanisms in Salmonella and warrant further investigations on the drivers behind the emergence of resistant clones.

Lociq provides a loci-seeking approach for enhanced plasmid subtyping and structural characterization.

Antimicrobial resistance (AMR) monitoring for public health is relying more on whole genome sequencing to characterize and compare resistant strains. This requires new approaches to describe and track AMR that take full advantage of the detailed data provided by genomic technologies. The plasmid-mediated transfer of AMR genes is a primary concern for AMR monitoring because plasmid rearrangement events can integrate new AMR genes into the plasmid backbone or promote hybridization of multiple plasmids. To better monitor plasmid evolution and dissemination, we developed the Lociq subtyping method to classify plasmids by variations in the sequence and arrangement of core plasmid genetic elements. Subtyping with Lociq provides an alpha-numeric nomenclature that can be used to denominate plasmid population diversity and characterize the relevant features of individual plasmids. Here we demonstrate how Lociq generates typing schema to track and characterize the origin, evolution and epidemiology of multidrug resistant plasmids.