Diverse bacterial hosts and potential risk of antibiotic resistomes in ship ballast water revealed by metagenomic binning.

Ship ballast water promoting the long-range migration of antibiotic resistance genes (ARGs) has raised a great concern. This study attempted to reveal ARGs profile in ballast water and decipher their hosts and potential risk using metagenomic approaches. In total, 710 subtypes across 26 ARG types were identified among the ballast water samples from 13 ships of 11 countries and regions, and multidrug resistance genes were the most dominant ARGs. The composition of ARGs were obviously different across samples, and only 5% of the ARG subtypes were shared by all samples. Procrustes analysis showed the bacterial community contributed more than the mobile genetic elements (MGEs) in shaping the antibiotic resistome. Further, 79 metagenome-assembled genomes (46 genera belong to four phyla) were identified as ARG hosts, with predominantly affiliated with the Proteobacteria. Notably, potential human pathogens (Alcaligenes, Mycolicibacterium, Rhodococcus and Pseudomonas) were also recognized as the ARG hosts. Above 30% of the ARGs hosts contained the MGEs simultaneously, supporting a pronounced horizontal gene transfer capability. A total of 43 subtypes (six percent of overall ARGs) of ARGs were assessed with high-risk, of which 23 subtypes belonged to risk Rank I (including rsmA, ugd, etc.) and 20 subtypes to the risk Rank II (including aac(6)-I, sul1, etc.). In addition, antibiotic resistance risk index indicated the risk of ARGs in ballast water from choke points of maritime trade routes was significantly higher than that from other regions. Overall, this study offers insights for risk evaluation and management of antibiotic resistance in ballast water.

Unraveling the effect of micro/nanoplastics on the occurrence and horizontal transfer of environmental antibiotic resistance genes: Advances, mechanisms and future prospects.

Microplastics can not only serve as vectors of antibiotic resistance genes (ARGs), but also they and even nanoplastics potentially affect the occurrence of ARGs in indigenous environmental microorganisms, which aroused great concern for the development of antibiotic resistance. This article specifically reviews the effects of micro/nanoplastics (concentration, size, exposure time, chemical additives) and their interactions with other pollutants on environmental ARGs dissemination. The changes of horizontal genes transfer (HGT, i.e., conjugation, transformation and transduction) of ARGs caused by micro/nanoplastics were also summarized. Further, this review systematically sums up the molecular mechanisms of micro/nanoplastics regulating HGT process of ARGs, including reactive oxygen species production, cell membrane permeability, transfer-related genes expression, extracellular polymeric substances production, and ARG donor-recipient adsorption/contaminants adsorption/biofilm formation. The underlying mechanisms in changes of bacterial communities induced by micro/nanoplastics were also discussed as it was an important factor for structuring the profile of ARGs in the actual environment, including causing environmental stress, providing carbon sources, forming biofilms, affecting pollutants distribution and environmental factors. This review contributes to a systematical understanding of the potential risks of antibiotic resistance dissemination caused by micro/nanoplastics and provokes thinking about perspectives for future research and the management of micro/nanoplastics and plastics.

Cemented K-wire external fixation in juxta-articular enchondroma-related phalangeal pathological fracture.

PURPOSE: This study aimed to introduce a technique of external fixation using a combination of bone cement and K-wires, to treat pathological fractures related to solitary digital enchondroma close to the finger joints. METHODS: From October 2015 to January 2021, 21 patients (8 males and 13 females) with acute pathological fracture due to solitary digital enchondroma close to the finger joints were treated with cemented K-wire external fixators. Mean age was 32 (19-51) years. The digits involved were the index (n = 4), long (n = 4), ring (n = 6), and little (n = 7) fingers. Time to bone healing and complications were assessed. At final follow-up, active range of motion, grip strength and key pinch strength of the tumor-involved and contralateral healthy digits were measured and compared. Functional outcomes were evaluated on Takigawa criteria. Pain was measured on a 10-cm visual analog scale. We assessed the affected upper extremity on the Musculoskeletal Tumor Society score questionnaire. RESULTS: Mean bone healing time was 5.5 (4-8) weeks. Pin site infection was observed in 1 patient and cured with dressing changes. Mean follow-up was 34 months, with no recurrences or refractures. Mean active range of motion of the proximal interphalangeal joint, grip and key pinch strength of the involved digits reached 92%, 97%, and 99% of the contralateral digits, respectively. On Takigawa criteria, 20 functional results were excellent and 1 good. Mean pain score was 1 (0-3) cm. Mean Musculoskeletal Tumor Society score was 95 (80-100). CONCLUSION: The combination of bone cement and K-wires is a reliable technique for pathological fracture related to solitary enchondroma close to the joints of the digits, leading to good functional outcomes. LEVEL OF EVIDENCE: Therapeutic study, Level IVa.

Anterior superior iliac spine distraction for severe and recalcitrant diabetic foot ulcers.

PURPOSE: The study aimed to introduce anterior superior iliac spine distraction to treat severe and recalcitrant diabetic foot ulcers. For comparison, we also included another group of diabetic foot ulcers treated with proximal tibial cortex transverse distraction. METHODS: From February 1998 to February 2020, 87 patients (87 feet) with severe and recalcitrant diabetic foot ulcers were treated. The mean age of patients at surgery was 64 years (range, 47 to 87 years). The severity of the narrowed artery was assessed using the ankle-brachial index test. For comparison, another group of 91 patients (91 diabetic foot ulcers) treated with proximal tibial cortex transverse distraction was included. RESULTS: The mean preoperative ankle-brachial indexes of the two groups were 0.41±0.07 and 0.39±0.05 (OR 0.65 [95% CI -0.77 to 1.58]; P=0.62), respectively. The mean preoperative limb pain was 3.42±2.84 cm and 3.52±3.11 cm (OR 1.54 [95% CI -077 to 1.35]; P=0.083), respectively. At the 2-year follow-up visit, ulcers healed in 72 (83%) and 74 (81%) patients, respectively (P=0.188). The mean postoperative limb pain was 0.52±0.23 cm and 0.49±0.41 cm (OR 2.32 [95% CI -0.27 to 1.66]; P=0.078), respectively. Pin-site infection occurred in 2 patients and 8 patients (P=0.09), respectively. Ulcer recurrence occurred in 13 (15%) patients and 15 (16%) patients (P=0.205), respectively. CONCLUSIONS: Anterior superior iliac spine transverse distraction may be an effective alternative treatment for severe and recalcitrant diabetic foot ulcers. It may be associated with fewer distraction-site complications than proximal tibial cortex transverse distraction. LEVEL OF EVIDENCE: Therapeutic study, Level IIa.