Contamination of equipment and surfaces in the operating room anesthesia workspace: a cross-sectional study

ABSTRACT BACKGROUND: Contamination of the breathing circuit and medication preparation surface of an anesthesia machine can increase the risk of cross-infection. OBJECTIVE: To evaluate the contamination of the anesthetic medication preparation surface, respiratory circuits, and devices used in general anesthesia with assisted mechanical ventilation. DESIGN AND SETTING: Cross-sectional, quantitative study conducted at the surgical center of a philanthropic hospital, of medium complexity located in the municipality of Três Lagoas, in the eastern region of the State of Mato Grosso do Sul. METHODS: Eighty-two microbiological samples were collected from the breathing circuits. After repeating the samples in different culture media, 328 analyses were performed. RESULTS: A higher occurrence of E. coli, Enterobacter spp., Pseudomonas spp., Staphylococcus aureus, and Streptococcus pneumoniae (P < 0.001) were observed. Variations were observed depending on the culture medium and sample collection site. CONCLUSION: The study findings underscore the inadequate disinfection of the inspiratory and expiratory branches, highlighting the importance of stringent cleaning and disinfection of high-touch surfaces.

Testing for the ability to modify antibiotics of Panus tigrinus 8/18 Lentinus strigosus 1566 laccase

Abstract In advanced biotechnology, the utilization of enzymes to achieve new or modified compounds with antibacterial, fungicidal, and anti-cancer specifications is crucial. Mushroom lactases are a hopeful biocatalyst for the synthesis and modification of different compounds. They are an accessible and inexpensive enzyme for the preparation of reaction objects and have recently received attention. Laccase purification was performed from basidiomycete Lentinus strigosus (LS) in several stages: Stage 1. On ion-exchange chromatography on TEAE Servacell 23 (400 ml), two distinctly separated laccase activity peaks were observed, eluted from the carrier at 0.21 and 0.27 M NaCl. In order to reduce the loss of enzymes, all fractions with laccase activity were collected, concentrated, and desalted using an ultrafiltration cell (Amicon, United States) with a UM-10 membrane. Stage 2. The resulting preparation with laccase activity was applied to a Q-Sepharose column (60 ml). Two well-separated peaks with laccase activity were obtained during the elution: laccase I (0.12 M NaCl) and laccase II (0.2 M NaCl). Stage 3. In the course of further purification of both enzymes, carried out on anion-exchange carrier Resource Q (6 ml), a broken gradient was used: 0 - 10%, 10 - 20%, and 20 - 100% with 1M NaCl. Stage 4. Both laccase I and laccase II, obtained after Resource Q, were desalted, concentrated to 1 ml each, and applied to a Superdex 75 gel filtration column. As a result, two laccases were obtained in a homogeneous form.

Resumo Na biotecnologia moderna, o uso de enzimas para obter compostos novos ou modificados com propriedades antibacterianas, antifúngicas e anticancerígenas é crucial. Lactases de cogumelos são biocatalisadores promissores para síntese e modificação de diferentes compostos, por serem enzimas baratas e disponíveis para a preparação de componentes de reação, e vem recebendo a devida atenção recentemente. A purificação da lacase foi realizada a partir do basidiomiceto Lentinus strigosus em vários estágios: Etapa 1 - na cromatografia de troca iônica em TEAE Servacell 23 (400 ml), foram observados dois picos de atividade da lacase distintamente separados, com eluição do transportador a 0,21 e 0,27 M de NaCl. Para reduzir a perda de enzimas, todas as frações com atividade de lacase foram coletadas, concentradas e dessalinizadas em uma célula de ultrafiltração (Amicon, Estados Unidos) com membrana UM-10; Etapa 2 - a preparação resultante com atividade de lacase foi aplicada a uma coluna Q-Sepharose (60 ml). Durante a eluição, foram obtidos dois picos bem separados com atividade de lacase: lacase I (NaCl 0,12 M) e lacase II (NaCl 0,2 M); Etapa 3 - no decurso da purificação adicional de ambas as enzimas, realizada no Recurso Q de transportador de troca aniônica (6 ml), um gradiente quebrado foi usado: 0-10%, 10-20% e 20-100% com NaCl 1M; Etapa 4 - tanto a lacase I como a lacase II, obtidas após o Recurso Q, foram dessalinizadas e concentradas para 1 ml cada e aplicadas a uma coluna de filtração em gel Superdex 75. Como resultado, duas lacases foram obtidas de forma homogênea.

Testing for the ability to modify antibiotics of Panus tigrinus 8/18 Lentinus strigosus 1566 laccase / Teste de capacidade para modificar antibióticos a partir da lacase de Panus tigrinus 8/18 e Lentinus strigosus 1566

In advanced biotechnology, the utilization of enzymes to achieve new or modified compounds with antibacterial, fungicidal, and anti-cancer specifications is crucial. Mushroom lactases are a hopeful biocatalyst for the synthesis and modification of different compounds. They are an accessible and inexpensive enzyme for the preparation of reaction objects and have recently received attention. Laccase purification was performed from basidiomycete Lentinus strigosus (LS) in several stages: Stage 1. On ion-exchange chromatography on TEAE Servacell 23 (400 ml), two distinctly separated laccase activity peaks were observed, eluted from the carrier at 0.21 and 0.27 M NaCl. In order to reduce the loss of enzymes, all fractions with laccase activity were collected, concentrated, and desalted using an ultrafiltration cell (Amicon, United States) with a UM-10 membrane. Stage 2. The resulting preparation with laccase activity was applied to a Q-Sepharose column (60 ml). Two well-separated peaks with laccase activity were obtained during the elution: laccase I (0.12 M NaCl) and laccase II (0.2 M NaCl). Stage 3. In the course of further purification of both enzymes, carried out on anion-exchange carrier Resource Q (6 ml), a broken gradient was used: 0 - 10%, 10 - 20%, and 20 - 100% with 1M NaCl. Stage 4. Both laccase I and laccase II, obtained after Resource Q, were desalted, concentrated to 1 ml each, and applied to a Superdex 75 gel filtration column. As a result, two laccases were obtained in a homogeneous form.

Na biotecnologia moderna, o uso de enzimas para obter compostos novos ou modificados com propriedades antibacterianas, antifúngicas e anticancerígenas é crucial. Lactases de cogumelos são biocatalisadores promissores para síntese e modificação de diferentes compostos, por serem enzimas baratas e disponíveis para a preparação de componentes de reação, e vem recebendo a devida atenção recentemente. A purificação da lacase foi realizada a partir do basidiomiceto Lentinus strigosus em vários estágios: Etapa 1 - na cromatografia de troca iônica em TEAE Servacell 23 (400 ml), foram observados dois picos de atividade da lacase distintamente separados, com eluição do transportador a 0,21 e 0,27 M de NaCl. Para reduzir a perda de enzimas, todas as frações com atividade de lacase foram coletadas, concentradas e dessalinizadas em uma célula de ultrafiltração (Amicon, Estados Unidos) com membrana UM-10; Etapa 2 - a preparação resultante com atividade de lacase foi aplicada a uma coluna Q-Sepharose (60 ml). Durante a eluição, foram obtidos dois picos bem separados com atividade de lacase: lacase I (NaCl 0,12 M) e lacase II (NaCl 0,2 M); Etapa 3 - no decurso da purificação adicional de ambas as enzimas, realizada no Recurso Q de transportador de troca aniônica (6 ml), um gradiente quebrado foi usado: 0-10%, 10-20% e 20-100% com NaCl 1M; Etapa 4 - tanto a lacase I como a lacase II, obtidas após o Recurso Q, foram dessalinizadas e concentradas para 1 ml cada e aplicadas a uma coluna de filtração em gel Superdex 75. Como resultado, duas lacases foram obtidas de forma homogênea.

Sonication as a tool for disrupting biofilms and recovering microorganisms in bladder catheters / Sonicação como uma ferramenta para romper biofilmes e recuperar microrganismos em cateteres vesicais

Abstract Introduction: Urinary catheter-related infection is commonly associated with bacterial biofilm. The impact of anaerobes is unknown, but their detection in the biofilm on this device has not been previously reported. This study aimed to evaluate the capability to recovery strict, facultative, and aerobic microorganisms in patients using bladder catheters from ICUs using conventional culture, sonication, urinary analysis, and mass spectrometry. Methods: Parallel, sonicated bladder catheters from 29 critically ill patients were compared with their routine urine culture. Identification was performed using matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry. Results: The positivity rate in urine (n = 2, 3.4%) was lower than that in sonicated catheters (n = 7, 13.8%). Conclusion: Bladder catheter sonication showed more positive culture results than urine samples for anaerobic and aerobic microorganisms. The role of anaerobes in urinary tract infection and catheter biofilm is discussed.

Resumo Introdução: A infecção relacionada ao cateter urinário é comumente associada ao biofilme bacteriano. O impacto dos anaeróbios é desconhecido, mas sua detecção no biofilme deste dispositivo não foi relatada anteriormente. Este estudo teve como objetivo avaliar a capacidade de recuperar microrganismos estritos, facultativos e aeróbios em pacientes que utilizam cateteres vesicais de UTIs utilizando cultura convencional, sonicação, análise urinária e espectrometria de massa. Métodos: Paralelamente, foram comparados cateteres vesicais sonicados de 29 pacientes gravemente enfermos com sua urocultura de rotina. A identificação foi realizada utilizando dessorção/ionização a laser assistida por matriz com espectrometria de massa por tempo de voo. Resultados: A taxa de positividade na urina (n = 2; 3,4%) foi inferior à dos cateteres sonicados (n = 7; 13,8%). Conclusão: A sonicação do cateter vesical apresentou resultados de cultura mais positivos do que as amostras de urina para microrganismos anaeróbios e aeróbios. É discutido o papel dos anaeróbios na infecção do trato urinário e no biofilme do cateter.

Contaminación microbiana durante la atención odontológica por la producción de aerosoles y salpicaduras / Microbial contamination during dental care due to aerosol and splash production

RESUMEN Objetivo: Analizar la contaminación microbiana durante la atención odontológica por la producción de aerosoles y salpicaduras. Metodología: De tipo documental, bibliográfica. La búsqueda se realizó a través de las bases de datos PubMed y Scopus. Considerando los lineamientos de la declaración PRISMA obteniendo un total de 221 artículos. Posteriormente se aplicaron los criterios de exclusión como de inclusión, obteniendo un total de 25 artículos. Resultados: La carga microbiana presente en el ambiente odontológico ha sido analizada de manera cuantitativa a través de las Unidades Formadoras de Colonias (UFC) en diferentes espacios y superficies de las clínicas dentales. En conclusión: La contaminación microbiológica asociada con la generación de aerosoles es una problemática que se experimenta en la consulta diaria, relacionándose principalmente con procedimientos asociados con equipos como las piezas de mano de alta velocidad, el equipo ultrasónico y la jeringa triple.

ABSTRACT Objective: To analyze microbial contamination during dental care due to the production of aerosols and splashes. Methodology: Documentary, bibliographic type. The search was carried out through the Pubmed and SCOPUS databases. Considering the guidelines of the PRISMA declaration, a total of 221 articles were obtained. Subsequently, the exclusion and inclusion criteria were applied, obtaining a total of 25 articles. Results: The microbial load present in the dental environment has been analyzed quantitatively through Colony Forming Units (CFU) in different spaces and surfaces of dental clinics. In conclusion: Microbiological contamination associated with the generation of aerosols is a problem that is experienced in the daily dental practice, mainly related to procedures associated with equipment such as high-speed handpieces, ultrasonic equipment and triple syringe.

Physiochemistry and Microbiological Quality of Surface Water Body around Port Terminals in Southern Nigeria

Anthropogenic activities around the sea ports are capable of causing changes on the physicochemical and microbiological quality of water bodies along the port terminals. Such activities can cause an ecological imbalance in the water quality /ecosystem resulting in extinction of aquatic resources. The aim of this study therefore was to investigate the physicochemical and microbiological quality of surface water along the busy port terminals. Surface water samples were collected from Onne port terminal using sterile containers. The samples were collected during the wet and dry seasons between January to June 2021. The sterile bottles were filled with surface water samples and transported in an ice packed container to the Department of Microbiology Laboratory of the Rivers State University for analyses using standard analytical methods. Statistical analyses were carried out using ANOVA and All pairs tukey-kramer. Results of the physicochemical parameters showed that temperature, total dissolved solids, total suspended solids, nitrate and heavy metals were significantly higher during the dry season than the wet season at P ? 0.05 levels of significance. Seasonal variation with respect to microbial counts shows that Total Heterotrophic Bacteria, Total Heterotrophic Fungi, Total coliforms and Faecal coliforms had a mean value of 3.9±1.77 x 106; 0.8 ±0.05 x 104 ; 7.4 ±1.3 x 104 and 3.6 ±0.17 x 104 colony forming unit per millilitre respectively for wet season while the dry season had 1.6±0.77 x 106 , 0.5 ±0.01 x 104 , 4.6 ±0.17 x 104 and 2.7 ±1.03 x 104 cfu/ml respectively. In this study, the predominant bacterial isolates belonged to the genera of Vibrio, Pseudomonas, Klebsiella, Bacillus, Shigella, Staphylococcus, Salmonella, Proteus, Bacillus and Escherichia. coli. The results of physicochemical and microbiological characteristics including the heavy metals, were detected at concentrations on or below detection limits.. It is therefore suggested that relevant environmental regulatory bodies should maintain regular check to ensure that appropriate standards are maintained around seaports due to beehive of activities.

Microorganismos aislados en pacientes con mediastinitis poscirugía cardiaca en un hospital de cardiología de la Ciudad de México / Microorganisms isolated in patients with post-cardiac surgery mediastinitis at a cardiology hospital of Mexico City

Resumen Introducción: La mediastinitis posterior a cirugía cardiovascular deriva en estancia hospitalaria prolongada e incremento de los costos de la atención médica, y se asocia a elevada letalidad hospitalaria. Objetivo: Describir las características clínicas de los pacientes con mediastinitis posquirúrgica, incluyendo los microorganismos aislados, perfil de resistencia y supervivencia hospitalaria. Métodos: Estudio transversal de pacientes con mediastinitis posquirúrgica bacteriológicamente confirmada, atendidos en un hospital de cardiología de la Ciudad de México entre enero de 2017 y marzo de 2019. Resultados: Se incluyeron 58 casos de mediastinitis. La mediana de edad fue de 67 años. La mayoría de los sujetos fueron varones sometidos a revascularización miocárdica. Durante el seguimiento hospitalario, la letalidad por todas las causas y la secundaria a la mediastinitis fueron de 27.6 y 20.7 %, respectivamente. Los microorganismos más frecuentemente aislados fueron Staphylococcus aureus, Staphylococcus epidermidis y Escherichia coli. Se encontró alta resistencia a meticilina en los estafilococos coagulasa negativos y alta expresión de betalactamasas de espectro extendido en cepas de Escherichia coli y Klebsiella pneumoniae. Conclusiones: En los pacientes con mediastinitis posquirúrgica analizados se observó alta letalidad e importante resistencia antimicrobiana.

Abstract Introduction: Mediastinitis after cardiovascular surgery gives rise to prolonged hospital stay and increased medical care costs, and is associated with high in-hospital mortality. Objective: To describe the clinical characteristics of patients with post-surgical mediastinitis, including the isolated microorganisms, resistance profile, and in-hospital survival. Methods: Cross-sectional study of patients with bacteriologically-confirmed post-surgical mediastinitis cared for at a cardiology hospital in Mexico City between January 2017 and March 2019. Results: Fifty-eight cases of mediastinitis were included. Median age was 67 years. Most subjects were males who underwent myocardial revascularization. During in-hospital follow-up, all-cause and mediastinitis-related mortality were 27.6% and 20.7%, respectively. Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli were the most commonly isolated microorganisms. High resistance to methicillin was found in coagulase-negative staphylococci, as well as high expression of extended-spectrum beta-lactamases in Escherichia coli and Klebsiella pneumoniae strains. Conclusions: High mortality and significant antimicrobial resistance were found in patients with post-cardiac surgery mediastinitis.

Evaluating Bioremediation Potentials of Fungi Species (Alternaria Sp., Aspergillus Sp. and Fusarium Sp.) on Heavy Metals from Plausible Industrial Effluent Discharges in Mmiri Ele Stream in Nnewi, Anambra State, Nigeria

The greatest challenge of man today is to deal with metal pollution problems because unlike organic compounds which are decomposed naturally, heavy metals tend to persist on the aquatic environment, hence get accumulated at different sensitive sites. Given the growth in environmental awareness, emphasis is given on this exploration of environment friendly ways for decontamination procedures. Attention has been drawn to bioremediation which is a good alternative to conventional remediation technologies. The preference for it is based on the fact that it is of low cost, and generates non-toxic by products. Microorganisms have acquired a variety of mechanisms to adapt themselves to the toxicity of heavy metals. The results obtained from the bioremediation of cadmium, chromium and copper in both the water samples and sediment samples using Alternaria sp, Aspergillus sp and Fusarum sp, show that there is a significant decrease in the quantities of cadmium, chromium and copper in both the water samples and sediment samples upon treatments with the selected microorganisms. The result of the bioremediation of chromium shows a significant decrease in the amount of chromium in the sample from the mean value of 0.423 for pre-remediation treatment to 0.08 for post remediation treatment. There was also a reasonable decrease in the amount of copper metal in the water sample from 0.193 to 0.092. The post bioremediation of cadmium in sediment sample shows a significant decrease in the amount of cadmium from 0.2430 to 0.1880, tending towards the value of the control. The bioremediation of the heavy metals significantly reduced the amount of the heavy metals present in the polluted environment. Hence, it can be said that under suitable environmental and biochemical conditions, microorganisms can be used in the remediation of the heavy metals present in a heavy metal polluted environment.

Contaminación microbiana durante la atención odontológica por la producción de aerosoles y salpicaduras / Microbial contamination during dental care due to aerosol and splash production

Analizar la contaminación microbiana durante la atención odontológica por la producción de aerosoles y salpicaduras. Metodología: De tipo documental, bibliográfica. La búsqueda se realizó a través de la en las bases de datos Pubmed y SCOPUS. Considerando los lineamientos de la declaración PRISMA obteniendo un total de 221 artículos. Posteriormente se aplicó los criterios de exclusión como de inclusión, obteniendo un total de 25 artículos. Resultados: La carga microbiana presente en el ambiente odontológico ha sido analizada de manera cuantifica a través de Unidades Formadoras de Colonias (UFC) en diferentes espacios y superficies de las clínicas dentales. En conclusión: La contaminación microbiológica asociada con la generación de aerosoles es una problemática que se experimenta en la consulta diaria, relacionándose principalmente con procedimientos asociados con equipos como las piezas de mano de alta velocidad, el equipo ultrasónico y la jeringa triple.

To analyze microbial contamination during dental care due to the production of aerosols and splashes. Methodology: Documentary, bibliographic type. The search was carried out through the Pubmed and SCOPUS databases. Considering the guidelines of the PRISMA declaration, a total of 221 articles were obtained. Subsequently, the exclusion and inclusion criteria were applied, obtaining a total of 25 articles. Results: The microbial load present in the dental environment has been analyzed quantitatively through Colony Forming Units (CFU) in different spaces and surfaces of dental clinics. In conclusion: Microbiological contamination associated with the generation of aerosols is a problem that is experienced in the daily dental practice, mainly related to procedures associated with equipment such as high-speed handpieces, ultrasonic equipment and triple syringe.

Inocuidad alimentaria y enfermedades transmitidas por alimentos (ETAs); sus efectos en la salud humana: una revisión / Food safety and foodborne diseases; its effects on human health: a review

INTRODUCCIÓN: En la actualidad la Organización de las Naciones Unidas (ONU) como una de sus metas proyectadas al 2030 es que los alimentos sean inocuos, con seguridad alimentaria, nutritiva y suficiente, debido a que en los últimos años se ha incrementado el número de casos de Enfermedades Transmitidas por Alimentos (ETAs). La inocuidad de los alimentos es un principio básico de salud y como característica intrínseca de un alimento es que el mismo no debe causar daño a la salud. OBJETIVO: describir la importancia de la inocuidad alimentaria y los microorganismos patógenos más frecuentes que se presentan en los alimentos. METODOLOGÍA: se realizó una revisión narrativa conformada de artículos científicos a partir del año 2019 al 2023. RESULTADOS: los microoganismos que frecuentemente son causantes de las ETAs son: Salmonella, Staphylococcus aureus, E. coli, Hepatitis A, Vibrio cholerae, Listeria monocytogenes, ocasionando a nivel mundial elevados casos de diarreas relacionadas directamente con alimentos y agua contaminada, y que actualmente van en incremento. CONCLUSIÓN: las principales causas de las ETAs son por el aumento del comercio internacional de los alimentos contaminados, así como el incremento en la migración de aquellas personas que estén infectadas favoreciendo la propagación, reemergencia y aparición de microorganismos patógenos en alimentos contaminados por las malas prácticas de higiene, con la capacidad de generar infecciones, intoxicaciones y brotes en la población. Por lo anterior los organismos gubernamentales a nivel mundial, nacional y local establecen estrategias para abatir esta problemática de salud pública, pero son insuficientes, debiendo reforzar las acciones concretas de prevención y promoción.

INTRODUCTION: Due to the number of cases of Foodborne Diseases (ETAs) in recent years, the United Nations (UN) currently establishes as one of its goals for 2030 that food be safe, secure, nutritious, and sufficient. Food safety is a basic requirement, and an intrinsic characteristic of a food is that it should not negatively impact health. OBJECTIVE: to describe the importance of food safety and identify the most common pathogenic microorganisms that occur in food. Methodology: a narrative review was carried, out consisting of scientific articles from 2019 to 2023. RESULTS: the microorganisms that frequently cause ETAs are: Salmonella, Staphylococcus aureus, E. coli, Hepatitis A, Vibrio cholerae, Listeria monocytogenes, which cause frequent cases of diarrhea worldwide due to contaminated food and water, and which are currently increasing. CONCLUSION: the main causes of ETAs are the increase in international trade in contaminated foods, and the increase in the migration of people who are infected. Poor hygiene in food handling practices favor the contamination, spread, re-emergence and appearance of pathogenic microorganisms in foods, with the capacity to generate infections, poisonings and outbreaks in the population. Government agencies at the global, national, and local levels establish strategies to combat this public health problem, but they are insufficient, and specific prevention and promotion actions must be reinforced.

Effect of anaerobic or/and microaerophilic atmosphere on microcosm biofilm formation and tooth demineralization

Abstract Microcosm biofilms can reproduce the complexity of a dental biofilm. However, different forms of cultivation have been used. The impact of the culture atmosphere on the development of microcosm biofilms and their potential to cause tooth demineralization has not yet been deeply studied. Objective This study analyzes the effects of three experimental cultivation models (microaerophile vs. anaerobiosis vs. experimental mixed) on the colony-forming units (CFU) of the cariogenic microorganisms and tooth demineralization. Methodology 90 bovine enamel and 90 dentin specimens were distributed into different atmospheres: 1) microaerophilia (5 days, 5% CO2); 2) anaerobiosis (5 days, jar); 3) mixed (2 days microaerophilia and 3 days anaerobiosis), which were treated with 0.12% chlorhexidine (positive control - CHX) or Phosphate-Buffered Saline (negative control - PBS) (n=15). Human saliva and McBain's saliva containing 0.2% sucrose were used for microcosm biofilm formation, for 5 days. From the second day to the end of the experiment, the specimens were treated with CHX or PBS (1x1 min/day). Colony-forming units (CFU) were counted, and tooth demineralization was analyzed using transverse microradiography (TMR). Data were subjected to two-way ANOVA and Tukey's or Sidak's test (p<0.05). Results CHX was able to reduce total microorganism's CFU compared to PBS (differences of 0.3-1.48 log10 CFU/mL), except for anaerobiosis and microaerophilia in enamel and dentin biofilm, respectively. In the case of dentin, no effect of CHX on Lactobacillus spp. was observed. CHX significantly reduced enamel demineralization compared to PBS (78% and 22% reductions for enamel and dentin, respectively). Enamel mineral loss did not differ when compared with the other atmospheres; however, the enamel lesion depth was greater under anaerobiosis. Dentin mineral loss was lower under anaerobiosis when compared with the other atmospheres. Conclusion The type of atmosphere has, in general, little influence on the cariogenic ability of the microcosm biofilm.

UV-C light as an alternative for disinfecting orthodontic pliers / Luz UV-C como alternativa para desinfecção de alicates ortodônticos

Objetivo: Os ortodontistas usam alicates ortodônticos continuamente, e essas ferramentas têm um forte potencial para infecções nosocomiais. Este estudo teve como objetivo comparar a eficiência de três métodos de desinfecção de alicates ortodônticos. Material e Métodos: As pontas ativas de 26 alicates ortodônticos (cortadores distais e alicates Weingart) foram contaminadas com microrganismos, vírus e esporos S. aureus, E. coli e C. albicans. Os métodos de controle microbiano foram desinfecção com álcool 70%, esterilização com esferas de vidro (250 °C calor seco) e irradiação com luz ultravioleta (250 nm UV-C) por 30 e 60 segundos. O número de unidades formadoras de colônias (UFC) e unidades formadoras de placas (UFP) foi quantificado e comparado para cada microrganismo após incubação em placas de cultura. Resultados: Todas as pontas do alicate dos grupos que receberam luz ultravioleta ou foram submetidos à esterilização com esferas de vidro apresentaram número significativamente menor de esporos, bactérias e fungos do que suas respectivas amostras controle (p<0,001). A desinfecção física com luz UV-C pode representar uma alternativa confiável em comparação com outros métodos químicos e físicos devido ao aumento de microrganismos resistentes a produtos químicos e à emissão de subprodutos nocivos após o tratamento químico. Conclusão: Os métodos de controle microbiano testados foram eficazes na desinfecção de alicates ortodônticos, tornando a luz ultravioleta-C uma alternativa promissora para eliminar os microrganismos dos alicates (AU)

Objective: Orthodontists use orthodontic pliers continuously, and these tools have a strong potential for nosocomial infections. This study aimed to compare the efficiency of three methods for disinfecting orthodontic pliers. Material and Methods: The active tips of 26 orthodontic pliers (distal end cutters and Weingart pliers) were contaminated with S. aureus, E. coli, and C. albicans microorganisms, viruses, and spores. The microbial control methods were 70% alcohol disinfection, glass bead sterilization (250 °C dry heat), and ultraviolet light irradiation (250 nm UV-C) for 30 and 60 seconds. The number of colony-forming units (CFU) and plaque-forming units (PFU) was quantified and compared for each microorganism after incubation in culture plates. Results: All tips of the pliers in the groups that received ultraviolet light or were subjected to glass bead sterilization showed a significantly lower number of spores, bacteria, and fungi than their respective control samples (p<0.001). Physical disinfection with UV-C light may represent a reliable alternative compared to other chemical and physical methods due to the increase in microorganisms resistant to chemical products and the emission of harmful by-products after chemical treatment. Conclusion: The tested microbial control methods were effective in the disinfection of orthodontic pliers, making ultraviolet-C light a promising alternative to eliminate microorganisms from pliers (AU)

Microbial remediation of cadmium-contaminated soils and its mechanisms: a review / 生物工程学报

Excessive levels of cadmium (Cd) in soil exert serious negative impacts on soil ecosystems. Microorganisms are a common component of soil and show great potential for mitigating soil Cd. This review summarizes the application and remediation mechanisms of microorganisms, microbial-plants, and microbial-biochar in Cd-contaminated soil. Microorganisms such as Bacillus, Acinetobacter, Pseudomonas, and arbuscular mycorrhizal fungi (AMF) can change the biological validity of Cd through adsorption, mineralization, precipitation and dissolution. Different factors such as pH, temperature, biomass, concentration, and duration have significant effects on Cd bioavailability by microorganisms. Pseudomonas, Burkholderia, and Flavobacterium can promote the uptake of Cd2+ by hyperaccumulator through promotion and activation. Biochar, a soil amendment, possesses unique physicochemical properties and could act as a shelter for microorganisms in agriculture. The use of combined microbial-biochar can further stabilize Cd compared to using biochar alone.

Polyethylene biodegradation: current status and perspectives / 生物工程学报

Polyethylene (PE) is the most abundantly used synthetic resin and one of the most resistant to degradation, and its massive accumulation in the environment has caused serious pollution. Traditional landfill, composting and incineration technologies can hardly meet the requirements of environmental protection. Biodegradation is an eco-friendly, low-cost and promising method to solve the plastic pollution problem. This review summarizes the chemical structure of PE, the species of PE degrading microorganisms, degrading enzymes and metabolic pathways. Future research is suggested to focus on the screening of high-efficiency PE degrading strains, the construction of synthetic microbial consortia, the screening and modification of degrading enzymes, so as to provide selectable pathways and theoretical references for PE biodegradation research.

Preface to the special issue: biotechnology of plastic waste degradation and valorization / 生物工程学报

Synthetic plastics have been widely used in various fields of the national economy and are the pillar industry. However, irregular production, plastic product use, and plastic waste piling have caused long-term accumulation in the environment, contributing considerably to the global solid waste stream and environmental plastic pollution, which has become a global problem to be solved. Biodegradation has recently emerged as a viable disposal method for a circular plastic economy and has become a thriving research area. In recent years, important breakthroughs have been made in the screening, isolation, and identification of plastic-degrading microorganisms/enzyme resources and their further engineering, which provide new ideas and solutions for treating microplastics in the environment and the closed-loop bio-recycling of waste plastics. On the other hand, the use of microorganisms (pure cultures or consortia) to further transform different plastic degradants into biodegradable plastics and other compounds with high added value is of great significance, promoting the development of a plastic recycling economy and reducing the carbon emission of plastics in their life cycle. We edited a Special Issue on the topic of "Biotechnology of Plastic Waste Degradation and Valorization", focusing on the researches progress in three aspects: Mining microbial and enzyme resources for plastic biodegradation, Design and engineering of plastic depolymerase, and biological high-value transformation of plastic degradants. In total, 16 papers have been collected in this issue including reviews, comments, and research articles, which provide reference and guidance for further development of plastic waste degradation and valorization biotechnology.

Influence of Gut Microbiota and its Metabolites on Progression of Metabolic Associated Fatty Liver Disease / 中国医学科学杂志(英文版)

Metabolic associated fatty liver disease (MAFLD) has become a prevalent chronic liver disease worldwide because of lifestyle and dietary changes. Gut microbiota and its metabolites have been shown to play a critical role in the pathogenesis of MAFLD. Understanding of the function of gut microbiota and its metabolites in MAFLD may help to elucidate pathological mechanisms, identify diagnostic markers, and develop drugs or probiotics for the treatment of MAFLD. Here we review the pathogenesis of MAFLD by gut microbiota and its metabolites and discuss the feasibility of treating MAFLD from the perspective of gut microbes.

Correlation between rhizosphere environment and content of medicinal components of Arnebia euchroma / 中国中药杂志

This study aimed to explore the correlation between rhizosphere soil microorganisms of wild Arnebia euchroma and the content of medicinal components to provide guidance for the selection of the ecological planting base. The total DNA of rhizosphere soil microorganisms of wild A. euchroma was extracted, and the microbial community structure of rhizosphere soil microorganisms was analyzed by IlluminaMiseq high-throughput sequencing technology. The content of total hydroxynaphthoquinone pigment and β,β'-dimethylacrylalkannin in medicinal materials was determined by high-performance liquid chromatography(HPLC). The physicochemical pro-perties of rhizosphere soil of wild A. euchroma in main producing areas were determined, and the correlation of soil microbial abundance with index component content and soil physicochemical properties was analyzed by SPSS software. The results showed that the species composition of rhizosphere fungi and bacteria in A. euchroma from different habitats was similar at the phylum and genus levels, but their relative abundance, richness index(Chao1), and community diversity(Simpson) index were different. Correlation analysis showed that the content of available phosphorus in soil was positively correlated with the content of total hydroxynaphthoquinone pigment and β,β'-dimethylacrylalkannin, and the abundance of five fungal genera such as Solicoccozyma and six bacterial genera such as Pseudo-nocardia and Bradyrhizobium was positively correlated with the content of medicinal components in medicinal materials. The abundance of Bradyrhizobium was significantly positively correlated with the content of β,β'-dimethylacrylalkanin. The abundance of fungi such as Archaeorhizomyces was significantly positively correlated with the content of available phosphorus in rhizosphere soil, and Bradyrhizobium was significantly negatively correlated with soil pH. Therefore, the abundance of fungi and bacteria in the rhizosphere of A. euchroma has a certain correlation with the medicinal components and the physicochemical properties of the rhizosphere soil, which can provide a scientific basis for the selection of ecological planting bases in the later stage.

Progress in the relationship between head and neck squamous cell carcinom and the microbial community / 临床耳鼻咽喉头颈外科杂志

Microorganisms are one of the important factors which maintain the homeostasis of human health. Despite recent advances, the relationship between microorganisms and head and neck squamous cell carcinoma （HNSCC） is still unclear, and the impact of microorganisms on the incidence and prognosis of HNSCC cannot be neglected. Therefore, this article provides a systematic and comprehensive review summarizing the epidemiological evidence of microbial dysbiosis related to HNSCC and discusses the associations between them.

Effects of rumen microorganisms on the decomposition of recycled straw residue / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Recently, returning straw to the fields has been proved as a direct and effective method to tackle soil nutrient loss and agricultural pollution. Meanwhile, the slow decomposition of straw may harm the growth of the next crop. This study aimed to determine the effects of rumen microorganisms (RMs) on straw decomposition, bacterial microbial community structure, soil properties, and soil enzyme activity. The results showed that RMs significantly enhanced the degradation rate of straw in the soil, reaching 39.52%, which was 41.37% higher than that of the control on the 30th day after straw return. After 30 d, straw degradation showed a significant slower trend in both the control and the experimental groups. According to the soil physicochemical parameters, the application of rumen fluid expedited soil matter transformation and nutrient buildup, and increased the urease, sucrase, and cellulase activity by 10%‒20%. The qualitative analysis of straw showed that the hydroxyl functional group structure of cellulose in straw was greatly damaged after the application of rumen fluid. The analysis of soil microbial community structure revealed that the addition of rumen fluid led to the proliferation of Actinobacteria with strong cellulose degradation ability, which was the main reason for the accelerated straw decomposition. Our study highlights that returning rice straw to the fields with rumen fluid inoculation can be used as an effective measure to enhance the biological value of recycled rice straw, proposing a viable solution to the problem of sluggish straw decomposition.

Role of LC3-associated phagocytosis in regulating infection / 中华微生物学和免疫学杂志

LC3-associated phagocytosis (LAP) is a special phagocytosis occurring at the intersection of the two pathways of phagocytosis and autophagy. A hallmark event of the LAP process is the recruitment of microtubule-associated proteinⅠlight chain type 3-Ⅱ(LC3Ⅱ) to the phagosome surface of the monolayer membrane structure. The LAP pathway relies on the functions of the RUN domain and cysteine-rich domain containing, Beclin 1-interacting protein (Rubicon) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. The LC3-associated phagosome (LAPosome) binds to the lysosome to digest and degrade the contents. In recent years, increasing studies have found that LAP plays an important role in the infections caused by pathogenic microorganisms including fungi and bacteria. LAP is a crucial way in the host to resist and degrade the infection of pathogenic microorganisms. However, some pathogenic microorganisms can effectively escape from LAP in the host and even use LAPosome as a place for colonization and replication. This article summarized the recent progress in the role of LAP in host defense against pathogenic microorganism infection and the significance of it in the occurrence and development of diseases.