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Detecting antibiotic residues is vital to minimize their impact. Yet, existing methods are complex and costly. Biosensors offer an alternative. While many biosensors detect various antibiotics, specific ones for beta-lactams are lacking. To address this gap, a biosensor based on the AmpC beta-lactamase regulation system (ampR-ampC) from Pseudomonas sp. IB20, an Antarctic isolate, was developed in this study. The AmpR-AmpC system is well-conserved in the genus Pseudomonas and has been extensively studied for its involvement in peptidoglycan recycling and beta-lactam resistance. To create the biosensor, the ampC coding sequence was replaced with the mCherry fluorescent protein as a reporter, resulting in a transcriptional fusion. This construct was then inserted into Escherichia coli SN0301, a beta-lactam hypersensitive strain, generating a whole-cell biosensor. The biosensor demonstrated dose-dependent detection of penicillins, cephalosporins and carbapenems. However, the most interesting aspect of this work is the high sensitivity presented by the biosensor in the detection of carbapenems, as it was able to detect 8 pg/mL of meropenem and 40 pg/mL of imipenem and reach levels of 1-10 ng/mL for penicillins and cephalosporins. This makes the biosensor a powerful tool for the detection of beta-lactam antibiotics, specifically carbapenems, in different matrices., (© 2023 The Authors. Microbial Biotechnology published by Applied Microbiology International and John Wiley & Sons Ltd.)

Objectives: The main objective of this study was the genetic characterization of clinically relevant class 1 integrons carried by multidrug resistant bacteria isolated from the intestinal microbiota of aquaculture salmon treated with high concentrations of antibiotics., Methods: In 82 multidrug resistant bacterial isolates, the prevalence of both the conserved elements of the integrons, qacEΔ1 and sul1 genes, and the variable region (VR) was determined. Further, whole genome sequencing and complete genetic analysis was performed in VR-positive isolates., Results: Despite the fact that 100% of the bacterial isolates presented the intI1 gene, only 12.3% carried the qacEΔ1 and sul1 genes and only two (2.4%) presented a VR with gene cassettes. In the Pseudomonas baetica 25P2F9 isolate, a VR carrying aac(6')31, qacH, and bla OXA-2 gene cassettes was described, whereas the VR of Aeromonas salmonicida 30PB8 isolate showed a dfrA14 gene cassette. The array of gene cassettes found in the Pseudomonas isolate appears with high frequency in clinically relevant pathogens such as Pseudomonas aeruginosa or Escherichia coli. Additionally, it was possible to determine that these integrons are contained in plasmids and coul be easily transferred. Resistome analysis demonstrated that both isolates carried a great diversity of antibiotic resistance genes, including many β-lactamases. Even in the Aeromonas isolate a new oxacillin-hydrolyzing beta-lactamase gene was described (bla OXA-956 )., Conclusion: The presence of multidrug resistant bacteria and clinically relevant genetic elements in the salmon intestinal microbiota make the aquaculture a hotspot in the phenomenon of antibiotic resistance; therefore, the control of antibiotics used in this activity is a key point to avoid its escalation., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The irradiation of ( Z )-2-phenyl-4-aryliden-5(4 H )-thiazolones 2 with blue light (465 nm) in CH 2 Cl 2 solution promotes [2 + 2]-photocycloaddition of the exocyclic C═C bonds and the formation of the dispirocyclobutanes 3 . This reaction takes place with high stereoselectivity, given that the ε-isomer (1,3 head-to-tail syn coupling) is formed in more than 90% yield in most of the cases. However, irradiation of 5(4 H )-thiazolones 2 with blue light (456 nm) in dry MeOH in the presence of BF 3 ·OEt 2 leads to the monospirocyclobutanes 4 with full stereoselectivity, also affording the ε-isomer. A ring-opening reaction of only one of the thiazolone rings appears to have taken place in 4 upon methanolysis, leading to the corresponding ester and thioamide groups. The treatment of free 4-aryliden-5(4 H )-thiazolones 2 with a base in alcohol (NaOR/ROH) also produces a ring-opening reaction of the heterocycle by methanolysis, although, under these reaction conditions, further intramolecular S-attack at the exocyclic C(H)═C bond and cyclization is observed, forming the dihydrothiazoles 5 or 6 as mixtures of cis ( RS / SR )- and trans ( RR / SS )-isomers with high diastereomeric excess. trans -( RR/SS )-Dihydrothiazoles 6 can be isolated as pure diastereoisomers by column chromatography. Surprisingly, dihydrothiazoles 5 can also be obtained by the treatment of 4-aryliden-5(4 H )-thiazolones 2 with BF 3 ·OEt 2 in methanol in the absence of a base.

Antarctica harbors a great diversity of microorganisms, including bacteria, archaea, microalgae and yeasts. The Pseudomonas genus is one of the most diverse and successful bacterial groups described to date, but only eight species isolated from Antarctica have been characterized. Here, we present three potentially novel species isolated on King George Island. The most abundant isolates from four different environments, were genotypically and phenotypically characterized. Multilocus sequence analysis and 16S rRNA gene analysis of a sequence concatenate for six genes (16S, aroE, glnS, gyrB, ileS and rpoD), determined one of the isolates to be a new Pseudomonas mandelii strain, while the other three are good candidates for new Pseudomonas species. Additionally, genotype analyses showed the three candidates to be part of a new subgroup within the Pseudomonas fluorescens complex, together with the Antarctic species Pseudomonas antarctica and Pseudomonas extremaustralis. We propose terming this new subgroup P. antarctica. Likewise, phenotypic analyses using API 20 NE and BIOLOG ® corroborated the genotyping results, confirming that all presented isolates form part of the P. fluorescens complex. Pseudomonas genus research on the Antarctic continent is in its infancy. To understand these microorganisms' role in this extreme environment, the characterization and description of new species is vital., (Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.)

The high use of antibiotics for the treatment of bacterial diseases is one of the main problems in the mass production of animal protein. Salmon farming in Chile is a clear example of the above statement, where more than 5,500 tonnes of antibiotics have been used over the last 10 years. This has caused a great impact both at the production level and on the environment; however, there are still few works in relation to it. In order to demonstrate the impact of the high use of antibiotics on fish gut microbiota, we have selected four salmon farms presenting a similar amount of fish of the Atlantic salmon species (Salmo salar), ranging from 4,500 to 6,000 tonnes. All of these farms used treatments with high doses of antibiotics. Thus, 15 healthy fish were selected and euthanised in order to isolate the bacteria resistant to the antibiotics oxytetracycline and florfenicol from the gut microbiota. In total, 47 bacterial isolates resistant to florfenicol and 44 resistant to oxytetracycline were isolated, among which isolates with Minimum Inhibitory Concentrations (MIC) exceeding 2048 μg/mL for florfenicol and 1024 μg/mL for oxytetracycline were found. In addition, another six different antibiotics were tested in order to demonstrate the multiresistance phenomenon. In this regard, six isolates of 91 showed elevated resistance values for the eight tested antibiotics, including florfenicol and oxytetracycline, were found. These bacteria were called "super-resistant" bacteria. This phenotypic resistance was verified at a genotypic level since most isolates showed antibiotic resistance genes (ARGs) to florfenicol and oxytetracycline. Specifically, 77% of antibiotic resistant bacteria showed at least one gene resistant to florfenicol and 89% showed at least one gene resistant to oxytetracycline. In the present study, it was demonstrated that the high use of the antibiotics florfenicol and oxytetracycline has, as a consequence, the selection of multiresistant bacteria in the gut microbiota of farmed fish of the Salmo salar species at the seawater stage. Also, the phenotypic resistance of these bacteria can be correlated with the presence of antibiotic resistance genes., Competing Interests: The authors have declared that no competing interests exist.

Objective: To evaluate the biological effect of microengineered stent grooves (MSG) on early strut healing in humans by performing optical coherence tomography (OCT) analysis 3 weeks following the implantation., Background: In the experimental setting, MSG accelerate endothelial cell migration and reduce neointimal proliferation compared with bare metal stent (BMS)., Methods: A total of 37 patients undergoing percutaneous coronary intervention with de novo coronary lesions were randomly assigned to either MSG (n=19) or an identical BMS controls (n=18). All patients underwent OCT imaging at 3 weeks. A total of 7959 struts were included in the final analysis., Results: At 3 weeks following stent implantation, almost all struts analysed (~97%) had evidence of tissue coverage. The percentage of partially covered struts was comparable between both groups. However, the percentage of fully embedded struts was higher in the BMS group (81.22%, 49.75-95.52) compared with the MSG group (74.21%, 58.85-86.38). The stent-level analysis demonstrated reduction in neointimal formation (neointimal hyperplasia area and volume reduction of ~14% and ~19%, respectively) in the MSG versus the BMS group. In the strut-level analysis, an even greater reduction (~22% in neointimal thickness) was seen in the MSG group. Layered neointimal was present in ~6% of the OCT frames in the BMS group while it was not present in the MSG group., Conclusions: MSG induced a more homogeneous and predictable pattern of surface healing in the early stages following stent implantation. The biological effect of MSG on stent healing has the potential to improve the safety profile of current generation drug-eluting stents., Classifications: BMS, OCT, clinical trials., Competing Interests: Competing interests: None declared.

Aims: Bioresorbable polymer drug-eluting stent technologies have been considered to have the potential to enhance vascular healing by reducing polymer exposure to the vessel wall, potentially allowing the earlier discontinuation of dual antiplatelet therapy. At present, the early vascular healing response to this type of technologies is still unclear., Patients and Methods: The TIMELESS study is a multicenter, prospective, single-arm study that enrolled real-world patients undergoing percutaneous coronary intervention. All patients underwent Synergy stent implantation, which consists of a platinum-chromium platform coated with an ultra-thin abluminal bioabsorbable poly-D,L-lactide-co-glycolide polymer-eluting everolimus., Results: A total of 37 patients were included in the study. The majority of the patients underwent percutaneous coronary intervention because of acute coronary syndromes. At 3 months, angiographic follow-up showed a percentage diameter of stenosis of 8.1±7.5% and an angiographic late loss of 0.03±0.24 mm. In all analyzed struts, less than 1% of struts were definitely uncovered or covered with fibrin, 12.5% (5.0-18.5%) showed evidence of partial coverage, and the remaining (∼85%) were fully covered. No stent thrombosis was observed up to 12 months of clinical follow-up., Conclusion: In a real-world population, the implantation of a bioresorbable polymer drug-eluting stent resulted in almost complete strut coverage throughout the entire stent length at 3 months. The clinical implications for antiplatelet therapy and outcomes should be investigated further.

Testicular autotransplantation is an advanced technique for the correction of high intra-abdominal testicles with inadequate vascular length for repositioning in the scrotum. In the past, surgeons have often avoided this approach due to the extended operative time and the requirement for microsurgical equipment and training. Surprisingly, this procedure remains rare despite the fact that autotransplantation is sometimes the most viable option to relocate the testicle. Further, current advances in laparoscopic surgery allow for testicular harvesting with minimal morbidity and maximal vascular pedicle length. Here, the evolution and an approach combining these two techniques implemented successfully in five patients are presented., (© Thieme Medical Publishers.)

Chagasic megacolon has been reported in the southern cone countries of South America and is mainly associated with Trypanosoma cruzi II infection. Herein, we report the first case in Colombia of chagasic megacolon with cardiomyopathy associated with the T. cruzi I lineage. This finding suggests that in Colombia, as well as in other northern countries of South America and throughout Central America, where T. cruzi I is endemic, cardiomyopathy may not be the only clinical form of Chagas disease.

Background/purpose: Over 50 years ago, current tenets of distraction osteogenesis were developed through work on the lower extremity; however, the application of these tenets in the paediatric craniofacial skeleton remains questionable. Prompted by recent concern that traditional aspects of distraction may be either outdated or wholly inapplicable to the paediatric maxilla, we retrospectively evaluated maxillary distraction protocol using a 24-h latency period in conjunction with a distraction rate of 2mm/day., Methods: Following maxillary advancement via a distraction protocol consisting of a 24-h latency period and a distraction rate of 2mm/day, seven consecutive paediatric cases were evaluated. Standard profile photos and cephalometric films taken preoperatively, at device removal and at 1-year follow-up were compared. With the sella as the point of registration, pre- and post-distraction films were superimposed on the sella-nasion plane. Sella-nasion-subspinale, the angle of convexity, the distance from incisal edges to the y-axis, and angulation of the upper incisor to the sella-nasion plane were analysed to evaluate hard-tissue changes., Results: Patient age ranged from 3 to 14 years (mean=7.43 years). Maxillary distraction length averaged 11 mm (range=10-12 mm). Interval from device application to removal averaged 98 days (range=75-180 days). The interval of the active distraction ranged from 11 to 65 days (mean=24 days). From distraction completion to device removal averaged 85 days (range=60-150). Follow-up intervals ranged from 52 to 24 months (mean=34 months). All patients demonstrated substantial clinical advancement of the maxilla with correction of midfacial deficiencies. A single patient developed mild cellulitis at one skin-device interface; no other complications were noted. Cephalometric and clinical evaluations at 1 year post-distraction demonstrated stable results, and parental satisfaction was qualitatively high., Conclusions: The surgical dogma of lower-extremity distraction osteogenesis is not absolute and may not be optimal for use in the paediatric maxilla. Our results demonstrate effective maxillary correction following application of a 24-h latency period coupled with rapid distraction at 2mm/day. Our success with a short latency period and more rapid device expanse may be a product of the significant vascularity and improved healing potential of the paediatric maxilla.

In the United States, rhinoplasty has traditionally been performed in Caucasian patients. Ethnic rhinoplasty is often thought of as a procedure done to reshape the nose of a black or Asian patient. Little attention has been paid to rhinoplasty in Hispanic patients. There has been a large increase in the Hispanic population of the United States, and plastic surgeons will see a concomitant rise in requests for rhinoplasty among this population. In an effort to increase our understanding of Hispanic rhinoplasty, a retrospective review of a senior surgeon's experience was performed. A retrospective chart review was done examining the senior author's (S.S.) rhinoplasty practice over the past 10 years. Hispanic patients presenting for aesthetic and corrective rhinoplasty (cleft patients were excluded) were analyzed. The Hispanic nose was divided into three archetypes. Type I is characterized by a high radix and prominent vault; these noses should be corrected by dorsal reduction and resection of caudal septum. Type II is characterized by a dependent tip with inadequate projection; dorsal augmentation with diced cartilage and tip support with cartilage grafts are important. Osteotomies should generally be avoided in this group. Type III noses are characterized by a broad nasal base with thick skin and a wide tip; rhinoplasty in this group requires correction of the dorsum-base disproportion using several techniques including columellar struts, tip grafts, and dorsal augmentation. Hispanics are projected to become the largest minority population within the next 10 years, and rhinoplasty in this population will become more frequent over time. It behooves plastic surgeons to become familiar with the different archetypes of Hispanic noses and appropriate corrective techniques for each.

Of all the methods for repair of the unilateral cleft lip, none has gained as much popularity as the rotation-advancement. Millard's original principle of 50 years ago continues to guide surgeons in closure of the cleft lip. Unlike earlier procedures, the brilliance of the rotation-advancement is that it permits individual manipulation and modifications while maintaining Millard's original surgical and anatomical goals. Millard and many other surgeons have made modifications to adjust the procedure to each specific patient, to address some of its faults, and to gain new advantages. In this article, the authors review the techniques of Drs. Ralph Millard, Steve Byrd, Court Cutting, John Mulliken, and Samuel Stal. The variations from Millard's original technique are highlighted, including a discussion of the benefits of each modification.

As the most prominent facial feature, the nose carries an increased risk of traumatic injury. Nasal fracture is the most common bone injury of the adult face and frequently results from motor vehicle accidents, sports-related injuries, and altercations. Although often initially considered minor, nasal fracture may eventually result in significant cosmetic or functional defects. Optimal management of nasal trauma in the acute setting is critical in minimizing secondary nasal deformities. In recent years, numerous guidelines have been described to refine and optimize acute nasal trauma management. However, restoration of pretraumatic form and function remains a challenge. Commonly the product of a poorly addressed underlying structural injury, posttraumatic nasal deformity requiring subsequent rhinoplasty or septorhinoplasty remains in as many as 50 percent of cases. In this article, the authors review the anatomic, diagnostic, and management considerations as well as discuss their own experience in approaching nasal trauma and the deviated nose.

Pediatric vascular anomalies can be difficult to diagnose and complex to treat. One must be able to distinguish hemangiomas from various vascular malformations, as well as appreciate their dynamic course with time. Thorough understandings of the clinical and diagnostic techniques used to evaluate these lesions are paramount for the treating surgeon. In addition, knowledge of current treatments from watchful waiting to radical extirpation is mandatory. This must all be done in the setting of a developing child. We present a current review of the literature regarding the comprehensive care of pediatric vascular lesions.

Background: Distraction osteogenesis was initially devised as a way to lengthen the lower extremity. All the basic tenets of the technique were developed based on this use. This includes both the supposed need for a latency period before distraction begins (3 to 5 days) and the ideal rate of distraction (1 mm/day). There is no evidence that these values apply to craniofacial distraction osteogenesis, particularly in children. Indeed, with the markedly improved blood supply in the face when compared with the lower extremity and the use of the technique in children versus adults, one might assume that a shorter latency period and a more rapid rate of distraction are possible., Methods: This study is a retrospective review of 22 pediatric patients with mandibular hypoplasia undergoing mandibular distraction osteogenesis. All patients were operated on by a team consisting of an oral surgeon and a plastic surgeon. All the distraction devices used were external. All patients had a latency period, before activation, of less than 24 hours and a distraction rate of 2 mm/day., Results: Two patients developed cellulitis at the pin sites, one patient developed premature healing, one patient developed a nonunion that required further surgery. This was the only patient in the series who had distraction of a previous bone graft. No patient undergoing distraction of native mandible developed a nonunion., Conclusions: Eliminating the latency period and rapidly distracting the mandible in pediatric cases has an acceptably low complication rate. This benefits the patient in terms of an overall reduction in the amount of time that the child needs to remain in the distraction device. The patient spends less time with the distraction device, thus reducing the potential morbidity and increased cost of the treatment. Potential explanations for why this variation in distraction technique is successful include the improved blood supply in the face of children and the failure of external devices to translate all the distracted movements to the bone interface. Some of this force is translated into both bending of the pins and migration of the pins through bone. Although a latency period might be necessary in the distraction of the lower extremities, the application of this concept to the craniofacial skeleton in children is erroneous.

Plexiform neurofibromas traditionally have posed a surgical challenge in pediatric patients. Expert preoperative planning, advanced surgical techniques, and vigilant postoperative care results in minimal morbidity and resolution of tumor symptomatology. A retrospective review of four consecutive pediatric patients with massive head and neck neurofibromas who underwent single-stage total or near-total removal of their tumors was performed. All four patients had obstructive airway symptoms. There were two minor complications. All patients had complete relief of their symptoms and return of function without any additional neurologic deficits. It is possible to safely achieve total or near-total removal of extensive plexiform neurofibromas with minimal morbidity while restoring lost function.

Patients with cleft lip or palate encounter a myriad of difficulties in their early years of life, some of which begin at birth. The defect often impairs suckling and deglutition in the neonate. It can hinder appropriate speech development and may impose undue social and psychological stresses. Surgical and orthodontic interventions are essential and prosthetic palatal appliances play an important role not only throughout the patient's treatment course, but also in the treatment of unfavorable surgical sequelae.

Background: Acellular porcine dermis has been used as a soft-tissue substitute in Europe since 1998 and in the United States since 2000. Processing renders the composite acellular, reducing antigenicity and crosslinking the dermal collagen. The purpose of this study was to determine the long-term histologic response of this material to the transfer into a subcutaneous soft-tissue location in an in vivo mouse model., Methods: A total of 24 mice (ICR strain) underwent an initial procedure transplanting a segment of acellular porcine dermis into a dorsal subcutaneous pocket. The implants were examined for qualitative characteristics including rigidity, migration, inflammation, and healing response. Composites of skin, subcutaneous tissue, implant, and underlying muscle were harvested for histologic evaluation. The specimens were analyzed for inflammatory response, degree, and character of tissue incorporation and degree of implant resorption., Results: One of the 24 animals studied experienced extrusion of the implant. The remaining 23 implants persisted within their respective hosts until the time the animals were killed. The volume and weight of all of the implants remained unchanged from the preoperative to postoperative measurements. Dystrophic calcification and bone formation was seen at 12 months., Conclusions: The results do not suggest characteristics optimal for implants used in soft-tissue augmentation for the purpose of aesthetics. The porcine dermis would appear from these results to be better suited for situations that require strength and permanence of the implant.

Cutaneous mucormycosis in the immunocompetent patient is exceedingly rare. However, if the infection is not rapidly identified and aggressively treated, its progression is fast, fulminate, and characteristically fatal. This case report describes the treatment and surgical reconstruction of a previously healthy, immunocompetent girl after pervasive mucormycosis of the right face. The patient's diagnosis was established by tissue biopsy. She was promptly started on 1.5 mg/kg per day intravenous amphotericin B and underwent numerous surgical debridements resulting in a large defect of the right face. After 2 xenograft procedures the defect was covered with an autologous split thickness skin graft. During this procedure a submandibular 4 x 7-cm tissue expander with a remote occipital port was placed superficial to the platysma. Serial tissue expansion took place over 8 weeks without complication. The tissue expander was removed and the expanded flap was advanced over the freshly de-epithelialized defect. Revisional surgeries may yet be performed; notwithstanding, the patient and her parents are pleased with the current results. Although the management of cutaneous mucormycosis often involves disfiguring tissue resection, the current wealth of reconstructive modalities can greatly improve the aesthetic and functional outcomes of requisite therapy.

Learning Objectives: After studying this article, the participant should be able to: 1. Understand the different technical options available for repairing facial fractures. 2. Know which technical points facilitate performance of fixation of the facial skeleton by relatively inexperienced surgeons. 3. Have a basic understanding of the most common complications arising after facial fracture repair. 4. Have an understanding of how to avoid surgical complications following facial fracture repair., Background: The treatment of facial trauma is associated with a myriad of potential complications. This may be compounded by the relative lack of compliance seen in the patient population within an urban trauma center and by the requisite involvement of residents in this care., Methods: This study retrospectively evaluated 189 patients with a total of 294 separate fractures treated over a 3.5-year period., Results: The overall rate of complications was 7.8 percent., Conclusions: The experience at a high-volume level I trauma center with residents as the primary physicians has confirmed that facial trauma surgery may be undertaken with an acceptably low complication rate. Numerous technical factors were thought to be responsible for this, including the use of miniplates for treatment in the majority of mandibular fractures, overcorrection of orbital volume in fractures involving the globe, and the use of a transconjunctival incision with a lateral canthotomy for access to the lower eyelid structures.

Management algorithms for frontal sinus fractures vary widely. Appropriate treatment depends on an accurate diagnosis, focusing on the physical examination and data from computed tomography scans. One must pay particular attention to involvement of the nasofrontal duct and violation of the posterior table because it is from these injuries that so much of the morbidity relating to these fractures is incurred. In large part, in the most severe injuries, a successful outcome is contingent upon meticulous removal of all visible frontal sinus mucosa with occlusion of the nasofrontal duct if required.

Purpura fulminans associated with meningococcemia is a devastating disease in children. The tissue loss can be extensive and difficult to determine at the outset. The authors suggest a strategy to manage these wounds with the goal of preserving as much tissue and function as possible. At the present time, conservative therapy to the wounds appears to be the best course in the initial, critical phase, as long as no active local purulence is found. Debridement or amputation is performed when the nonviable tissue margins are delineated. Temporary coverage with allograft may be required; definitive coverage is accomplished when the local tissue perfusion has recovered. Future revisions are often necessary to improve these children's quality of life.