Restoring colistin sensitivity in colistin-resistant Salmonella and Escherichia coli: combinatorial use of berberine and EDTA with colistin.

The appearance and prevalence of multidrug-resistance (MDR) Gram-negative bacteria (GNB) have limited our antibiotic capacity to control bacterial infections. The clinical efficacy of colistin (COL), considered as the "last resort" for treating GNB infections, has been severely hindered by its increased use as well as the emergence and prevalence of mobile colistin resistance (MCR)-mediated acquired drug resistance. Identifying promising compounds to restore antibiotic activity is becoming an effective strategy to alleviate the crisis of increasing MDR. We first demonstrated that the combination of berberine (BBR) and EDTA substantially restored COL sensitivity against COL-resistant Salmonella and Escherichia coli. Molecular docking indicated that BBR can interact with MCR-1 and the efflux pump system AcrAB-TolC, and BBR combined with EDTA downregulated the expression level of mcr-1 and tolC. Mechanically, BBR combined with EDTA could increase bacterial membrane damage, inhibit the function of multidrug efflux pump, and promote oxidative damage, thereby boosting the action of COL. In addition, transcriptome analysis found that the combination of BBR and EDTA can accelerate the tricarboxylic acid cycle, inhibit cationic antimicrobial peptide (CAMP) resistance, and attenuate Salmonella virulence. Notably, the combination of BBR and EDTA with COL significantly reduced the bacterial load in the liver and spleen of a mice model infected with Salmonella. Our findings revealed that BBR and EDTA can be used as adjuvants collectively with COL to synergistically reverse the COL resistance of bacteria. IMPORTANCE: Colistin is last-resort antibiotic used to treat serious clinical infections caused by MDR bacterial pathogens. The recent emergence of transferable plasmid-mediated COL resistance gene mcr-1 has raised the specter of a rapid worldwide spread of COL resistance. Coupled with the fact of barren antibiotic development pipeline nowadays, a critical approach is to revitalize existing antibiotics using antibiotic adjuvants. Our research showed that berberine combined with EDTA effectively reversed COL resistance both in vivo and in vitro through multiple modes of action. The discovery of berberine in combination with EDTA as a new and safe COL adjuvant provides a therapeutic regimen for combating Gram-negative bacteria infections. Our findings provide a potential therapeutic option using existing antibiotics in combination with antibiotic adjuvants and address the prevalent infections caused by MDR Gram-negative pathogens worldwide.

A Clinical Study of Platelet-Rich Fibrin Combined With Autologous High-Density Fat Transplantation in Augmentation Rhinoplasty.

OBJECTIVE: This study was designed to analyze the clinical effect of autologous fat-granule transplantation in augmentation rhinoplasty and explore methods to improve the fat retention rate. METHODS: A total of 70 enrolled patients were randomly divided into 2 groups: the platelet-rich fibrin (PRF) combined with high-density fat transplantation group (combined group) and the conventional fat-granule transplantation group (control group; n = 35 in each group). In the combined group, an appropriate amount of autologous fat was extracted and centrifuged, and the lower layer of high-density fat was taken and mixed with PRF isolated from whole blood for autotransplantation. In the control group, only fat was extracted and centrifuged for transplantation. The patients were followed up with for more than one year to observe the short- and long-term effects, complications, safety, and patient satisfaction. RESULTS: Six months after the operation, the nasal shape was stable, the contour was higher and more stereoscopic than before, the average increase of nasal height was 3.0 mm in the combined group and 2.0 mm in the control group. No complications, such as fat embolism, infection, or necrosis occurred during the 1-year follow-up. The satisfaction rate between the 2 groups has statistical significance (P < .05). CONCLUSION: Overall, PRF combined with autologous high-density fat transplantation is simple to perform, has a significantly increased fat-retention rate than the control group, and has stable long-term effects without obvious adverse reactions. A sufficient amount of fat and PRF transplantation can achieve a good orthopedic effect. Thus, this method can be widely used in clinical augmentation rhinoplasty.

Clinical Application of a Bird-Beak-Type Z-Shaped Asymmetrical Flap in the Reconstruction of the Inner Canthus.

Objective: To introduce a new surgical method for the repair of a large inner canthus combined with tissue loss at the inner canthal angle of the eye by using a bird-beak-type z-shaped asymmetrical flap and to summarize its clinical effect. Method: A total of 56 patients with a large inner canthus were randomly selected, and a bird-beak-type z-shaped asymmetrical flap was used on the nasal side of the lower eyelid to repair and reconstruct the inner canthal folds. The inner canthal point was located according to physiological aesthetics. The short and long arms of the z-shaped asymmetrical flap were separated, replaced, fixed, and shaped to reconstruct the skin folds of the inner canthus and restore its aesthetic morphology. Results: All incisions after surgery achieved primary healing, and all 56 cases were followed up for 6-20 months (average 8.6 months). The caruncula lacrimalis was moderately exposed, the inner canthal angles possessed a natural appearance, and the results of the surgery were satisfactory. Five patients developed scar hyperplasia within one month after surgery, and arnica gel was applied topically for 3-6 months until the scar faded or disappeared, but no obvious scars were seen in the surgical area of the remaining patients. In two patients, the internal canthi were asymmetrical, but this improved after adjustment. Conclusion: Repair of a large inner canthus and tissue loss at the inner canthal angle of the eye using a bird-beak-type z-shaped asymmetrical flap is a simple operation, resulting in minimal trauma. Postoperatively, the inner canthal angle possessed a natural appearance with no obvious scarring.

Molecular Characterization of a Novel Integrative Conjugative Element ICEHpa1 in Haemophilus parasuis.

ICEHpa1 was identified in the genome of a serovar 8 Haemophilus parasuis ST288 isolate YHP170504 from a case of swine lower respiratory tract infection. The aim of the present study was to characterize the integrative conjugative element ICEHpa1 and its multiresistance region. Susceptibility testing was determined by broth microdilution and the complete ICEHpa1 was identified by WGS analysis. The full sequence of ICEHpa1 was analyzed with bioinformatic tools. The presence of ICEHpa1, its circular intermediate and integration site were confirmed by PCR and sequence analysis. Transfer of ICEHpa1 was confirmed by conjugation. ICEHpa1 has a size of 68,922 bp with 37.42% GC content and harbors 81 genes responsible for replication and stabilization, transfer, integration, and accessory functions, as well as seven different resistance genes [bla Rob- 3, tet(B), aphA1, strA, strB, aac(6)'-Ie-aph(2')-Ia, and sul2]. Conjugation experiments showed that ICEHpa1 could be transferred to H. parasuis V43 with frequencies of 6.1 × 10-6. This is the first time a multidrug-resistance ICE has been reported in H. parasuis. Seven different resistance genes were located on a novel integrative conjugative element ICEHpa1, which suggests that the ICEHpa1 is capable of acquiring foreign genes and serving as a carrier for various resistance genes.

Characterization of pTS14, an IncF2:A1:B1 Plasmid Carrying tet(M) in a Salmonella enterica Isolate.

The objective of this study was to explore the genetic and biological features of the tet(M)-harboring plasmid pTS14 in Salmonella enterica strain S14 isolated from a chicken fecal sample. Plasmid pTS14 was identified by conjugation, S1-pulsed-field gel electrophoresis (PFGE), Southern hybridization, and plasmid sequencing. The biological characteristics of pTS14 were assessed via stability, growth kinetics, and starvation survival experiments. Strain S14, belonging to ST3007, harbored a 119-kb tet(M)-bearing IncF2:A1:B1 conjugative plasmid pTS14. The plasmid pTS14 contained a novel transposon Tn6709 with the genetic structure IS26-tnpA1-tnpA2-Δorf13-LP-tet(M)-tnpX-ΔtnpR-IS26, and the resistance genes tet(B), tet(D), strAB, sul2, and bla TEM-1b. In addition, pTS14 was found to be highly stable in the recipient strain E. coli J53. The transconjugant TS14 exhibited a higher survival ratio than E. coli J53 under permanent starvation-induced stress. The tet(M)-bearing IncF2 epidemic plasmid lineage may accelerate the dissemination of tet(M) and other genes by coselection, which could constitute a potentially serious threat to clinical treatment regimens.