The presence of emerging biological pollutants in treated wastewater effluents has gained attention due to increased interest in water reuse. To evaluate the effectiveness of the removal of such contaminants by the conventional wastewa-ter treatment process, the fate and decay kinetics of NDM-1-positive Escherichia coli strain PI7 and its plasmid-encoded antibiotic resistance genes (ARGs) were assessed in microcosms of anaerobic and aerobic sludge. Results showed that E. coli PI7 decayed at a significantly lower rate under anaerobic conditions. Approximate half-lives were 32.4 1.4 h and 5.9 0.9 h in the anaerobic and aerobic microcosms, respectively. In the aerobic microcosms, after 72 h of operation, E. coli PI7 remained detectable , but no further decay was observed. Instead, 1 in every 10,000 E. coli cells was identified to be recalcitrant to decay and persist indefinitely in the sludge. ARGs associated with the E. coli PI7 strain were detected to have transferred to other native microorganisms in the sludge or were released to the liquid fraction upon host decay. Extracellular DNA quickly degraded in the liquid fraction of the aerobic sludge. In contrast, no DNA decay was detected in the anaerobic sludge water matrix throughout the 24-h sampling period. This study suggests an increased likelihood of environmental dispersion of ARGs associated with anaerobically treated wastewater effluents and highlights the potential importance of persister cells in the dissemination of E. coli in the environment during reuse events of treated wastewater. IMPORTANCE This study examines the decay kinetics of a pathogenic and antibiotic resistant strain of Escherichia coli in microcosms simulating biological treatment units of aerobic and anaerobic sludge. The results of this study point at a significantly prolonged persistence of the E. coli and the associated antibiotic resistance gene in the anaerobic sludge. However, horizontal transfer of the plasmid encoding the antibiotic resistance gene was detected in the aerobic sludge by a cultivation method. A subpopulation of persister E. coli cells was also detected in the aerobic sludge. The findings of this study suggest potential areas of concern arising from pathogenic and antibiotic-resistant E. coli during both anaerobic and aerobic sludge treatment processes.
A craniomedial approach to the scapulohumeral joint of the dog is described for the removal of large, intraarticular cartilaginous bodies from the medial aspect of the joint. This technique was used successfully in 4 dogs with chronic osteochondritis dissecans in which the medial aspect of the joint was inaccessible through a standard lateral approach. From the Departments of Small AnimalClinical Sciences, t Veterinary Biology, and the *
Summary: In this study the authors evaluated the grade of acceptance and the operating conditions of unilateral primary herniorrhaphy under local anesthesia and monitored anesthesia care (MAC). The amount of pain in the immediate postoperative period was assessed and the efficacy of treatment using a popular' non-opiate analgesic, magnesic metamizol, by the oral route was studied. In a period of six months 63 consecutive patients were operated on by the same surgeon using the same technique of hernia repair (Shouldice technique) with local infiltration anesthesia supplemented by MAC in the form of conscious sedation. A mixture of 300 mg of plain mepivacaine and 50 mg of plain bupivacaine was used for infiltration. A standard dose of fentanyl o.lo mg and midazolam 2 mg was used for conscious sedation. Propofol in continuous infusion was also employed. The average dose of propofol varied from 1-3 mg/kg/h. Conscious level was assessed using a five-point sedation score. A level-3 end point was persued (closed eyes, but answer verbal orders). Pain intensity in the postoperative period was measured by the visual analogue.' scale (VAS) and the verbal pain scale (VPS), based on the McGill pain questionnaire. The operating conditions were excellent in all cases except in three patients. In no case conversion to general anesthesia was necessary. In the postoperative period, 5 patients (8%) never felt pain and 58 (92%) felt pain on the average 4 hours 36 minutes after the local infiltration (VAS=2.5; VPS=1.45). Of the 58 patients 49 took the first dose of oral analgesic 6 hours 4o mirmtes after infiltration (VAS=4; VPS=1.97). All patients were satisfied with the anesthetic-surgical technique and were ready to repeat the experience. However, when the patients took the second dose of oral analgesic 28% of them had moderate pain and 9% severe pain. Our conclusions are that local infiltration with MAC is a valid and satisfying experience for both the patient and the surgeon. Nevertheless, further attempts should be made to better the postoperative pain relief when the oral route is elected.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.