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1.
Sci Total Environ ; 773: 145152, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33940720

RESUMEN

In the recent decades, the role of wastewater treatment plants has been entrenched for the dissemination of antibiotic resistant bacteria into the environment. The present study explores the dynamics of earthworms-microorganisms interactions involved in the high treatment efficacy of vermifiltration technology along with reduction of antibiotic resistant bacteria (ARB). This study is the first of its kind to investigate the performance efficacy of vermifilter (VF) for clinical laboratory wastewater treatment. The results of the study showed that earthworms and VF associated microbial community had a significant effect on Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) reduction (78-85%), coliforms and pathogen removal (>99.9%) and caused a significant shift in the prevalence pattern of ARB. Molecular profiling of resistance causing genes such as ESBL (blaSHV, blaTEM and blaCTX-M), MRSA (mec-A) and Colistin (mcr-1) confirmed the probable mechanisms behind the resistance pattern. The microbial community diversity in the influent, earthworm's coelomic fluid and gut and filter media layers associated with the VF assists in the formation of biofilm, which helps in the removal of pathogens from the wastewater. This biofilm formation further results in a paradigm shift in the resistance profile of ARB and ARG, specifically most effective against drugs, targeting cell wall and protein synthesis inhibition such as Ampicillin, Ticarcillin, Gentamicin and Chloramphenicol. These findings further validate vermifiltration technology as a sustainable and natural treatment technology for clinical laboratory wastewater, specifically for the removal of pathogens and antibiotic resistance.


Asunto(s)
Oligoquetos , Purificación del Agua , Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina , Animales , Antibacterianos/farmacología , Bacterias/genética , Laboratorios , Oligoquetos/genética
2.
Sci Total Environ ; 773: 145643, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33940744

RESUMEN

Antibiotic resistance genes (ARGs) and microplastics in the environment are of great public concern due to their potential risk to human health. Microplastics can form distinct bacterial communities and absorb pollutants from the surrounding environment, which provide potential hosts and exert possible selection pressure of ARGs. We provide a practical evaluation of the scientific literature regarding this issue. The occurrence and transport of ARGs on microplastics in wastewater treatment plants, aquatic, terrestrial, and air environments were summarized. Selective enrichment of ARGs and antibiotic resistance bacteria on microplastics have been confirmed in different environments. Aggregates may be crucial to understand the behavior and transport of ARGs on microplastics, especially in the aquatic and terrestrial environment. Microplastics could be a carrier of ARGs between the environment and animals. Accumulation of pollutants and dense bacterial communities on microplastics provide favorable conditions for higher transfer rate and evolution of ARGs. More studies are still needed to understand the enrichment, transport, and transfer of ARGs on microplastics and provide a fundamental basis for evaluating their exposure health risk to humans.


Asunto(s)
Microplásticos , Plásticos , Animales , Antibacterianos , Farmacorresistencia Microbiana/genética , Genes Bacterianos , Humanos , Plásticos/toxicidad
3.
Sci Total Environ ; 773: 145706, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33940765

RESUMEN

The hydrophilic biomaterial was constructed based on the soluble extracellular polysaccharides (s-EPS) secreted by Bacillus megaterium and zeolitic imidazolate framework-8 (ZIF-8), namely ZIF-8@s-EPS, wrapped in s-EPS shell with ZIF-8 as the core. ZIF-8@s-EPS was used as a novel multifunctional biomaterial in water treatment for the first time. Unexpectedly, results showed ZIF-8@s-EPS with strong synergistic effect presented multifunctional performances including descaling, antifouling and antibacterial. Scale inhibition efficiency reached 98.63% for CaCO3 and as high as 99.40% for CaSO4 at concentration 20.00 mg/L. The synergy of s-EPS and ZIF-8 demonstrated effective antibacterial activity against Pseudomonas aeruginosa and inhibitory effect on biofilms, and result presented that ZIF-8@s-EPS could inhibit the growth of nearly 89.4% P. aeruginosa. Therefore, the obtained insights will shed light on the development of s-EPS modified biomaterials in water treatment.


Asunto(s)
Purificación del Agua , Zeolitas , Antibacterianos/farmacología , Materiales Biocompatibles , Imidazoles , Polisacáridos
4.
Sensors (Basel) ; 21(9)2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33946193

RESUMEN

This study reports a novel, fast, easy, and sensitive detection method for bacteria which is urgently needed to diagnose infections in their early stages. Our work presents a complex of poly(amidoamine) dendrimer modified by phenylboronic acid and labeled by a fluorescent dansyl group (Dan-B8.5-PAMAM). Our system detects bacteria in 20 min with a sensitivity of approximately 104 colony-forming units (CFU)·mL-1. Moreover, it does not require any peculiar technical skills or expensive materials. The driving force for bacteria recognition is the binding between terminal phenylboronic acids on the probe and bacteria's surface glycolipids, rather than electrostatic interactions. The aggregation caused by such binding reduces fluorescence. Even though our recognition method does not distinguish between live or dead bacteria, it shows selective antibacterial activity towards Gram-negative bacteria. This study may potentially contribute a new method for the convenient detection and killing of bacteria.


Asunto(s)
Dendrímeros , Antibacterianos , Ácidos Borónicos , Colorantes , Bacterias Gramnegativas
5.
Int J Mol Sci ; 22(5)2021 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-33802469

RESUMEN

In this study, nanocomposite hydrogels composed of sodium carboxymethylated starch (CMS)-containing CuO nanoparticles (CMS@CuO) were synthesized and used as experimental wound healing materials. The hydrogels were fabricated by a solution-casting technique using citric acid as a crosslinking agent. They were characterized by Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) to evaluate their physicochemical properties. In addition, swelling, antibacterial activities, antioxidant activities, cytotoxicity, and in vivo wound healing were investigated to evaluate the wound healing potential of the CMS@CuO nanocomposite hydrogels. Growth inhibition of the Gram-positive and Gram-negative pathogens, antioxidant activity, and swelling were observed in the CMS@CuO nanocomposite hydrogels containing 2 wt.% and 4 wt.% CuO nanoparticles. The hydrogel containing 2 wt.% CuO nanoparticles displayed low toxicity to human fibroblasts and exhibited good biocompatibility. Wounds created in rats and treated with the CMS@2%CuO nanocomposite hydrogel healed within 13 days, whereas wounds were still present when treated for the same time-period with CMS only. The impact of antibacterial and antioxidant activities on accelerating wound healing could be ascribed to the antibacterial and antioxidant activities of the nanocomposite hydrogel. Incorporation of CuO nanoparticles in the hydrogel improved its antibacterial properties, antioxidant activity, and degree of swelling. The present nanocomposite hydrogel has the potential to be used clinically as a novel wound healing material.


Asunto(s)
Antibacterianos/química , Antioxidantes/química , Cobre/química , Hidrogeles/química , Nanopartículas/química , Almidón/análogos & derivados , Cicatrización de Heridas/efectos de los fármacos , Animales , Antibacterianos/farmacología , Antioxidantes/farmacología , Células Cultivadas , Quitosano/química , Fibroblastos/efectos de los fármacos , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Nanocompuestos/química , Ratas , Ratas Wistar , Almidón/química , Difracción de Rayos X
6.
Environ Int ; 152: 106453, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33798824

RESUMEN

Conjunctive transfer of antibiotic resistance genes (ARGs) among bacteria driven by plasmids facilitated the evolution and spread of antibiotic resistance. Heavy metal exposure accelerated the plasmid-mediated conjunctive transfer of ARGs. Nanomaterials are well-known adsorbents for heavy metals removal, with the capability of combatting resistant bacteria/facilitating conjunctive transfer of ARGs. However, co-effect of heavy metals and nanomaterials on plasmid-mediated conjunctive transfer of ARGs was still unknown. In this study, we investigated the effect of the simultaneous exposure of Cd2+ and nano Fe2O3 on conjugative transfer of plasmid RP4 from Pseudomonas putida KT2442 to water microbial community. The permeability of bacterial cell membranes, antioxidant enzyme activities and conjugation gene expression were also investigated. The results suggested that the combination of Cd2+ and high concentration nano Fe2O3 (10 mg/L and 100 mg/L) significantly increased conjugative transfer frequencies of RP4 plasmid (p < 0.05). The most transconjugants were detected in the treatment of co-exposure to Cd2+ and nano Fe2O3, the majority of which were identified to be human pathogens. The mechanisms of the exacerbated conjugative transfer of ARGs were involved in the enhancement of cell membrane permeability, antioxidant enzyme activities, and mRNA expression levels of the conjugation genes by the co-effect of Cd2+ and nano Fe2O3. This study confirmed that the simultaneous exposure to Cd2+and nano Fe2O3 exerted a synergetic co-effect on plasmid-mediated conjunctive transfer of ARGs, emphasizing that the co-effect of nanomaterials and heavy metals should be prudently evaluated when combating antibiotic resistance.


Asunto(s)
Antibacterianos , Cadmio , Farmacorresistencia Microbiana/genética , Genes Bacterianos , Plásmidos/genética , Antibacterianos/farmacología , Cadmio/toxicidad , Conjugación Genética
7.
BMJ Case Rep ; 14(4)2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33811095

RESUMEN

Chronic otorrhoea from a tympanic membrane perforation is common. We present the case of a patient who had already received seemingly adequate treatment for his condition in the past. Yet, he presented to our outpatient clinic with worsening otalgia and otorrhoea, progressive hearing loss and a new tympanic membrane perforation. After a thorough otological evaluation, the patient's medical history and the histological specimen from a previous operation were reviewed. The findings met the diagnostic criteria of eosinophilic otitis media. After treatment with topic triamcinolone through the perforated tympanic membrane, the patient's otalgia subsided, hearing levels were improved and the size of the tympanic membrane perforation decreased.


Asunto(s)
Pérdida Auditiva , Otitis Media Supurativa , Otitis Media , Perforación de la Membrana Timpánica , Timpanoplastia , Antibacterianos/uso terapéutico , Enfermedad Crónica , Dolor de Oído/etiología , Pérdida Auditiva/tratamiento farmacológico , Pérdida Auditiva/etiología , Humanos , Masculino , Persona de Mediana Edad , Otitis Media/tratamiento farmacológico , Otitis Media Supurativa/complicaciones , Otitis Media Supurativa/tratamiento farmacológico , Otitis Media Supurativa/cirugía , Resultado del Tratamiento , Perforación de la Membrana Timpánica/tratamiento farmacológico , Perforación de la Membrana Timpánica/cirugía
8.
Water Res ; 197: 117087, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33819658

RESUMEN

While the ubiquitous presence of comammox in engineered systems provides the foundation of developing a novel biological nitrogen removal process, factors contributing to the comammox dynamics in engineered systems have not been well resolved. Here, we investigate the long-term effects of ten different antibiotics on microbial community dynamics in activated sludge and the results show that both types and concentrations of antibiotics affect the taxonomic composition of nitrifiers, including comammox, ammonia-oxidizing bacteria, and canonical nitrite-oxidizing bacteria. Specifically, phylogenetically different comammox Nitrospira were selectively enriched by four types of antibiotics (i.e., ampicillin, kanamycin, lincomycin, and trimethoprim). Comparative genomic analysis of the four newly identified comammox clade A Nitrospira revealed that the comammox enriched by antibiotics shared the conserved key metabolic potentials, such as carbon fixation, complete ammonia oxidation, and utilization of hydrogen as alternative electron donors, among the known comammox organisms. Comammox strains enriched in this study also encoded genes involved in formate and cyanate metabolism that were recently reported in comammox clade A organisms from wastewater treatment systems. Our findings highlight that the comammox in activated sludge ecosystems possess high metabolic versatility than previously recognized and could be selectively enriched by some antibiotics.


Asunto(s)
Amoníaco , Nitrificación , Antibacterianos , Ecosistema , Nitritos , Oxidación-Reducción , Filogenia , Aguas del Alcantarillado
9.
Water Res ; 197: 117075, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33819660

RESUMEN

Although photo-driven advanced oxidation processes (AOPs) have been developed to treat wastewater, few studies have investigated the feasibility of AOPs to simultaneously remove antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs) and micropollutants (MPs). This study employed a modified photo-Fenton process using ethylenediamine-N,N'-disuccinic acid (EDDS) to chelate iron(III), thus maintaining the reaction pH in a neutral range. Simultaneous removal of ARB and associated extracellular (e-ARGs) and intracellular ARGs (i-ARGs), was assessed by bacterial cell culture, qPCR and atomic force microscopy. The removal of five MPs was also evaluated by liquid chromatography coupled with mass spectrometry. A low dose comprising 0.1 mM Fe(III), 0.2 mM EDDS, and 0.3 mM hydrogen peroxide (H2O2) was found to be effective for decreasing ARB by 6-log within 30 min, and e-ARGs by 6-log within 10 min. No ARB regrowth occurred after 48-h, suggesting that the proposed process is an effective disinfectant against ARB. Moreover, five recalcitrant MPs (carbamazepine, diclofenac, sulfamethoxazole, mecoprop and benzotriazole at an initial concentration of 10 µg/L each) were >99% removed after 30 min treatment in ultrapure water. The modified photo-Fenton process was also validated using synthetic wastewater and real secondary wastewater effluent as matrices, and results suggest the dosage should be doubled to ensure equivalent removal performance. Collectively, this study demonstrated that the modified process is an optimistic 'one-stop' solution to simultaneously mitigate both chemical and biological hazards.


Asunto(s)
Peróxido de Hidrógeno , Contaminantes Químicos del Agua , Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina , Antibacterianos/farmacología , Bacterias , Farmacorresistencia Microbiana/genética , Compuestos Férricos , Oxidación-Reducción , Aguas Residuales , Contaminantes Químicos del Agua/análisis
10.
Am J Vet Res ; 82(5): 358-366, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33904804

RESUMEN

OBJECTIVE: To evaluate physical compatibility of small animal (SAE) and large animal (LAE) injectable formulations of enrofloxacin with select IV fluids and drugs. SAMPLE: 162 admixtures containing SAE or LAE with saline (0.9% NaCl) solution, lactated Ringer solution (LRS), Plasma-Lyte A (PLA), 6% hydroxyethylstarch 130/0.4 (HES), metoclopramide, or ampicillin-sulbactam. PROCEDURES: In the first of 2 simultaneously conducted experiments, admixtures containing enrofloxacin (10 mg/kg) and a volume of IV fluid that would be administered over a 20-minute period when dosed at the maintenance infusion rate (40 mL/kg/d for saline solution, LRS, and PLA and 20 mL/kg/d for HES) were created. In the second experiment, enrofloxacin (10 mg/kg) was admixed with saline solution (40 mL/kg/d) and metoclopramide (2 mg/kg/d) or ampicillin-sulbactam (30 mg/kg). In both experiments, admixture components were infused into a flask over 20 minutes assuming patient weights of 5, 10, and 20 kg. Admixtures were created by use of undiluted SAE and SAE diluted 1:1 with saline solution and undiluted LAE and LAE diluted 1:1 and 1:10 with saline solution. Admixtures were assessed for physical incompatibility at 0, 15, 30, and 60 minutes after completion of mixing. Physical incompatibility was defined as gross precipitation, cloudiness, Tyndall effect, or change in turbidity. RESULTS: Admixtures containing undiluted SAE or LAE were physically incompatible with saline solution, PLA, LRS, and HES. Because saline solution was used to dilute SAE and LAE, all admixtures containing diluted SAE or LAE were also physically incompatible. Physical compatibility of enrofloxacin with metoclopramide or ampicillin-sulbactam could not be assessed because those admixtures also contained saline solution. CONCLUSIONS AND CLINICAL RELEVANCE: Enrofloxacin was physically incompatible with all tested solutions.


Asunto(s)
Preparaciones Farmacéuticas , Animales , Antibacterianos , Incompatibilidad de Medicamentos , Enrofloxacina , Infusiones Intravenosas/veterinaria
11.
Shanghai Kou Qiang Yi Xue ; 30(1): 33-37, 2021 Feb.
Artículo en Chino | MEDLINE | ID: mdl-33907776

RESUMEN

PURPOSE: Inhibitory effects of theaflavin(TF) on planktonic and sessile bacterial cells of Streptococcus mutans were investigated in the present study. METHODS: MIC and MBC of TF/EGCG/CHX on S. mutans UA159 were determined. Furthermore, biofilms were formed and treated with agents, then proliferative activity and viability of bacterial cells were detected. SPSS 22.0 software package was used for statistical analysis. RESULTS: TF was found to inhibit planktonic cells of S. mutans UA159 with MIC of 500 µg/mL and MBC of 1 mg/mL. Moreover, bacterial cells of S. mutans UA159 in the biofilms treated with TF at concentrations higher than 2*MIC had lower proliferative activity and viability than those in control-treated biofilms. CONCLUSIONS: TF efficiently suppressed proliferative activity and viability of S. mutans biofilms, which provided theoretical basis for clinic applications of TF.


Asunto(s)
Biflavonoides , Catequina , Antibacterianos , Biopelículas , Pruebas de Sensibilidad Microbiana , Plancton , Streptococcus mutans
12.
Bioresour Technol ; 331: 125060, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33798863

RESUMEN

Fly ash (FA), obtained as waste materials from industrial power plants, is generated in large quantities and low recycling. In this study, re-generation of waste FA as cost-effective materials with adsorbent and antibacterial applications was assessed. Alkaline/zinc-activated fly ash nanocomposite (A-FA/Zn) was prepared using one-pot hydrothermal technique. Those nanocomposites are characterized by high surface area and negatively surface charge, which are important influences contributing to an enhancement in adsorption capacity via increase in the number of adsorptive sites and electrostatic interaction between dye molecules-nanocomposites. Additionally, the presence of Zn ions in the prepared nanocomposites represents a key advantage with respect to enhancing antibacterial activity. The feasibility of further enhancing adsorption and antibacterial mechanisms was also examined. It is anticipated that the findings of this study will provide useful information with respect to the development of simple, eco-friendly and low-cost A-FA/Zn with multifunctional applications as organic dye removal and antibacterial purposes.


Asunto(s)
Nanocompuestos , Contaminantes Químicos del Agua , Adsorción , Álcalis , Antibacterianos/farmacología , Ceniza del Carbón , Contaminantes Químicos del Agua/análisis , Zinc
13.
Bioresour Technol ; 331: 125065, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33819908

RESUMEN

The co-existence of nitrate, manganese (Mn), and antibiotics are of a wide concern. In this study, a denitrifying and manganese-oxidizing Zoogloea Q7 bacterium was immobilized using polyvinyl alcohol/sodium alginate with sponge cube (PVA/SA@sponge cube) in the reactor. The optimal operation parameters of the bioreactor were explored. Maximum nitrate, Mn(II), and tetracycline (TC) removal efficiencies of 93.00, 72.34, and 57.32% were achieved with HRT of 10 h, pH of 6.5, Mn(II) concentration of 20 mg L-1, and TC of 1 mg L-1, respectively. Fluorescence excitation-emission matrix (EEM) proved that the microorganism in the bioreactor was greatly active. Scanning electron microscope (SEM) images demonstrated that Zoogloea Q7 was commendably immobilized on the novel material. X-ray diffraction (XRD) analysis suggested that the bioprecipitate was mainly composed of MnO2 and MnCO3. Through high-throughput analysis, Zoogloea sp. Q7 was considered to be the dominant bacteria present in the bioreactor.


Asunto(s)
Nitratos , Alcohol Polivinílico , Alginatos , Antibacterianos , Reactores Biológicos , Desnitrificación , Manganeso , Compuestos de Manganeso , Óxidos
14.
JCI Insight ; 6(7)2021 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-33830084

RESUMEN

Proline-glycine-proline (PGP) and its acetylated form (Ac-PGP) are neutrophil chemoattractants generated by collagen degradation, and they have been shown to play a role in chronic inflammatory disease. However, the mechanism for matrikine regulation in acute inflammation has not been well established. Here, we show that these peptides are actively transported from the lung by the oligopeptide transporter, PEPT2. Following intratracheal instillation of Ac-PGP in a mouse model, there was a rapid decline in concentration of the labeled peptide in the bronchoalveolar lavage (BAL) over time and redistribution to extrapulmonary sites. In vitro knockdown of the PEPT2 transporter in airway epithelia or use of a competitive inhibitor of PEPT2, cefadroxil, significantly reduced uptake of Ac-PGP. Animals that received intratracheal Ac-PGP plus cefadroxil had higher levels of Ac-PGP in BAL and lung tissue. Utilizing an acute LPS-induced lung injury model, we demonstrate that PEPT2 blockade enhanced pulmonary Ac-PGP levels and lung inflammation. We further validated this effect using clinical samples from patients with acute lung injury in coculture with airway epithelia. This is the first study to our knowledge to determine the in vitro and in vivo significance of active matrikine transport as a mechanism of modulating acute inflammation and to demonstrate that it may serve as a potential therapeutic target.


Asunto(s)
Lesión Pulmonar Aguda/inmunología , Cefadroxilo/farmacología , Inflamación/metabolismo , Oligopéptidos , Prolina/análogos & derivados , Simportadores , Animales , Antibacterianos/farmacología , Transporte Biológico Activo/inmunología , /metabolismo , Células Cultivadas , Factores Quimiotácticos/inmunología , Factores Quimiotácticos/farmacología , Quimiotaxis de Leucocito/inmunología , Modelos Animales de Enfermedad , Matriz Extracelular , Proteínas de la Matriz Extracelular/metabolismo , Humanos , Ratones , Oligopéptidos/inmunología , Oligopéptidos/farmacología , Prolina/inmunología , Prolina/farmacología , Simportadores/antagonistas & inhibidores , Simportadores/metabolismo
15.
Water Sci Technol ; 83(7): 1578-1590, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33843744

RESUMEN

Antibiotic resistance genes (ARGs), as a new type of environmental pollutant that threaten human health, have been detected in the effluent of sewage treatment systems. In this study, the removal from water of ARGs, 16S rRNA, class 1 integron (intI1), and dissolved organic carbon (DOC) were investigated using processes combining nano-iron (nFe), ultrasound (US), activated persulfate (PS) and ultrafiltration (UF). The oxidation mechanism was also studied. The results showed that both nFe and US activation could improve the oxidative effect of PS, and the effect of nFe was better than that of US. Compared with PS-UF, nFe/PS-UF and US/PS-UF significantly enhanced the removal of various ARGs and DOC. nFe/PS-UF was the most effective treatment, reducing cell-associated and cell-free ARGs by 1.74-3.14-log and 1.00-2.61-log, respectively, while removing 30% of DOC. Pre-oxidation methods using PS, nFe/PS, and US/PS significantly enhanced the efficacy of UF for removing DOC with molecular weights above 50 kDa and below 10 kDa, but the removal of DOC between 10 and 50 kDa decreased. The free radicals SO4·- and ·OH were shown to participate in the process of ARGs oxidation.


Asunto(s)
Antibacterianos , Ultrafiltración , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Hierro , ARN Ribosómico 16S , Aguas Residuales
16.
BMC Res Notes ; 14(1): 144, 2021 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-33865447

RESUMEN

OBJECTIVE: The aim of this study was to investigate the genetic relatedness and antimicrobial resistance among Shigella species isolated from food and stool samples. Using cross sectional study method, Shigella spp. were isolated from food and clinical samples using culture-based, biochemical and serological methods. Antimicrobial susceptibility and genetic relatedness among the isolates were evaluated using disk diffusion and RAPD-PCR methods respectively. RESULTS: The prevalence of Shigella spp. were 4.84 and 7.7% in food and stool samples respectively. All food isolates were Sh. sonnei. 91.42% of the Shigella stool isolates were Sh. sonnei. 62.5% of food isolates were resistant to tetracycline. 46.8, 50 and 65.8% of clinical isolates were resistant to imipenem, amikacin and azithromycin respectively. 50 and 85.7% of the food and clinical isolates respectively were MDR. Dendrogram generated by RAPD-PCR showed that the isolates from food and stool samples were categorized in a same group. Close genetic relatedness between MDR Shigella isolates from food and clinical samples indicate that foods can be considered as one of the main vehicles for transmission of MDR Shigella to human causing acute diseases. Survey of MDR Shigella among food and clinical samples is strongly suggested to be implemented.


Asunto(s)
Diarrea/tratamiento farmacológico , Disentería/tratamiento farmacológico , Heces/microbiología , Contaminación de Alimentos/análisis , Microbiología de Alimentos/métodos , Pruebas de Sensibilidad Microbiana/métodos , Shigella/efectos de los fármacos , Shigella/aislamiento & purificación , Antibacterianos/farmacología , Preescolar , Estudios Transversales , ADN Bacteriano/genética , Diarrea/epidemiología , Diarrea/microbiología , Disentería/epidemiología , Disentería/microbiología , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Irán/epidemiología , Reacción en Cadena de la Polimerasa , Técnica del ADN Polimorfo Amplificado Aleatorio , Shigella/genética
17.
Am J Case Rep ; 22: e930888, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33861730

RESUMEN

BACKGROUND Rahnella aquatilis is a facultatively anaerobic, gram-negative rod bacterium commonly found in freshwater. There are few cases of bacteremia caused by Rahnella aquatilis in the literature and even fewer cases reported of it causing sepsis in immunocompetent individuals. In this case report, we present a rare case of an immunocompetent individual who developed sepsis secondary to bacteremia caused by Rahnella aquatilis. CASE REPORT A 37-year-old immunocompetent man with cerebral palsy and chronic enterocutaneous fistulas, with an indwelling peripherally inserted central catheter (PICC) line for total parenteral nutrition (TPN), presented to the emergency department with complaints of increased enteric drainage from his fistula, rigors, and subjective fevers following a mechanical fall, which occurred approximately 1 week before. The day following admission, the patient developed septic shock and was transferred to the intensive care unit for vasopressor support. He was given intravenous cefepime and metronidazole for empiric therapy. Blood cultures grew Rahnella aquatilis, and antibiotic therapy was de-escalated to monotherapy with intravenous ceftriaxone. The patient's condition stabilized, his PICC line was replaced, and he was successfully discharged, and continued on outpatient antibiotic therapy with ceftriaxone. CONCLUSIONS This case report represents a novel presentation of septic shock secondary to bacteremia caused by a gram-negative rod bacterium, Rahnella aquatilis, in an immunocompetent host dependent on TPN via a PICC line. This case also demonstrates that Rahnella aquatilis can be susceptible to and treated successfully with intravenous ceftriaxone. Bacteremia caused by Rahnella aquatilis can cause a swift, aggressive decompensation and should be treated with antibiotics immediately.


Asunto(s)
Bacteriemia/diagnóstico , Parálisis Cerebral/complicaciones , Infecciones por Bacterias Gramnegativas/diagnóstico , Rahnella/aislamiento & purificación , Choque Séptico/microbiología , Adulto , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Inmunocompetencia , Masculino , Choque Séptico/diagnóstico
18.
J Water Health ; 19(2): 216-228, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33901019

RESUMEN

Multidrug-resistant Staphylococcus aureus strains have been commonly found in hospitals and communities causing wide ranges of infections among humans and animals. Typing of these strains is a key factor to reveal their clonal dissemination in different regions. We investigated the prevalence and dissemination of different clonal groups of S. aureus with resistance phenotype to multiple antibiotics in two sewage treatment plants (STPs) in Tehran, Iran over four sampling occasions. A total of 576 S. aureus were isolated from the inlet, sludge and outlet. Of these, 80 were identified as methicillin-resistant S. aureus (MRSA) and were further characterized using a combination of Phene Plate (PhP) typing, staphylococcal cassette chromosome mec (SCCmec), ccr types, prophage and antibiotic-resistant profiling. In all, eight common type (CT) and 13 single PhP type were identified in both STPs, with one major CT accounting for 38.8% of the MRSA strains. These strains belonged to three prophage patterns and five prophage types with SCCmec type III being the predominant type. Resistance to 11 out of the 17 antibiotics tested was significantly (P < 0.0059) higher among the MRSA isolates than methicillin-sensitive S. aureus (MSSA) strains. The persistence of the strains in samples collected from the outlet of both STPs was 31.9% for MRSA and 23.1% for MSSA. These data indicated that while the sewage treatment process, in general, is still useful for removing most MRSA populations, some strains with SCCmec type III may have a better ability to survive the STP process.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Antibacterianos/farmacología , Humanos , Irán , Staphylococcus aureus Resistente a Meticilina/genética , Pruebas de Sensibilidad Microbiana , Aguas del Alcantarillado , Staphylococcus aureus/genética
19.
Artículo en Ruso | MEDLINE | ID: mdl-33901385

RESUMEN

On the basis of declassified materials from the Russian State Archive of Economics and State Archive of the Russian Federation, for the first time, the history of the United Nations Relief and Rehabilitation Administration (UNRRA) project for the supply of penicillin factories in the post-war years to two republics of the USSR - Ukraine and Belarus is considered. It is shown that the project initially had political significance, since the demonstration of humane intentions served to strengthen the political authority of the United States. However, despite the declaration, the Anglo-American leadership of UNRRA approached the implementation of the project formally and hardly planned its completion. This was expressed in non-compliance with requirements for completeness of equipment, violation of delivery deadlines, constant attempts to reduce and contain them, in non-supplying adequate technical documentation and specialists for setting up production. The delay in the delivery time of equipment resulted in its rapid moral obsolescence. The modernization of partially supplied factories was impeded by embargo on the export of advanced industrial equipment from the United States having strategic importance. The incompleteness of the project contributed to further split in international relations.


Asunto(s)
Antibacterianos , Penicilinas , Federación de Rusia , U.R.S.S. , Naciones Unidas , Estados Unidos
20.
Chimia (Aarau) ; 75(4): 267-271, 2021 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-33902793

RESUMEN

The emergence and spread of antibiotic resistance is a major societal challenge and new antibiotics are needed to successfully fight bacterial infections. Because the release of antibiotics into wastewater and downstream environments is expected to contribute to the problem of antibiotic resistance, it would be beneficial to consider the environmental fate of antibiotics in the development of novel antibiotics. In this article, we discuss the possibility of designing peptide-based antibiotics that are stable during treatment (e.g. in human blood), but rapidly inactivated through hydrolysis by peptidases after their secretion into wastewater. In the first part, we review studies on the biotransformation of peptide-based antibiotics during biological wastewater treatment and on the specificity of dissolved extracellular peptidases derived from wastewater. In the second part, we present first results of our endeavour to identify peptide bonds that are stable in human blood plasma and susceptible to hydrolysis by the industrially produced peptidase Subtilisin A.


Asunto(s)
Aguas Residuales , Purificación del Agua , Antibacterianos , Farmacorresistencia Microbiana , Humanos , Péptidos
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