Comparación de la actividad antimicrobiana de cementos selladores en endodoncia / Comparison of the antimicrobial activity of sealing cements in endodontics

Introducción: la persistencia de microorganismos en los conductos radiculares es uno de los principales factores del fracaso endodóncico. Por ello la importancia de conocer las propiedades antimicrobianas de los distintos tipos de selladores. Objetivo: realizar una comparación con base en la evidencia disponible sobre la actividad antimicrobiana de los diferentes cementos selladores en endodoncia. Material y métodos: la información fue recopilada de las bases de datos PubMed y Google Académico en el idioma inglés y español, publicados en el periodo 2014-2023. Resultados: un gran número de microorganismos se encuentran presentes en los diferentes tipos de infecciones de origen endodóncico, se han identificado más de 500 especies microbianas, entre ellas bacterias, hongos, arqueas y virus. Los cementos selladores se pueden clasificar según su composición química, en cementos a base de óxido de zinc-eugenol, hidróxido de calcio, a base de ionómero de vidrio, silicona, resina y biocerámicos. Conclusión: los cementos selladores que mostraron mayor actividad antimicrobiana contra los microorganismos persistentes fueron los cementos a base de óxido de zinc-eugenol, resina y biocerámicos. Sin embargo, se identificó que cada autor utilizó diferentes métodos y tiempos, por lo tanto, no es posible lograr definir con exactitud qué cemento sellador posee la mejor capacidad antimicrobiana (AU)

Introduction: the persistence of microorganisms in root canals is one of the main factors of endodontic failure. Therefore, the importance of knowing the antimicrobial properties of the different types of sealants. Objective: to make a comparison based on the available evidence on the antimicrobial activity of the different endodontics sealers. Material and methods: the information was collected from PubMed and Google Academic databases in English and Spanish, published in the period 2014-2023. Results: a large number of microorganisms are present in the different types of infections of endodontic origin, more than 500 microbiological species have been identified, including bacteria, fungi, archaea and viruses. Sealer cements can be classified according to their chemical composition, into cements based on zinc oxide-eugenol, calcium hydroxide, based on glass ionomer, silicone, resin and bioceramics. Conclusion: sealer cements that showed the highest antimicrobial activity against persistent microorganisms were zinc oxide-eugenol, resin, and bioceramic-based cements. However, it was identified that each author used different methods and times, therefore, it is not possible to accurately define which sealer cement has the best antimicrobial capacity (AU)

Microbial-lipid Metabolism Mechanism of Liver Injury in Wistar Rats Caused by Dictamni Cortex- Flavescens Sophora / 中国实验方剂学杂志

ObjectiveTo observe the microbial changes in Wistar rats with liver injury caused by the Dictamni Cortex-Flavescens Sophora by high-throughput sequencing technology and investigate the potential mechanism of liver injury caused by the Dictamni Cortex-Flavescens Sophora. MethodFemale Wistar rats were randomly divided into four groups： normal group， as well as low-dose， medium-dose， and high-dose groups of traditional Chinese medicine （TCM）. The rats were gavaged with the Dictamni Cortex-Flavescens Sophora in different doses （4.125， 8.25， 16.5 g·kg-1 of raw drug respectively） for 28 days， and the general condition was recorded. The liver-body weight ratio was calculated， and the biochemical indexes of serum were observed. The Hematoxylin-eosin （HE） staining was used to observe pathological changes in the liver， and 16S rDNA high-throughput sequencing was utilized to detect fecal microbial changes in rats. ResultCompared with the normal group， Dictamni Cortex-Flavescens Sophora increased the liver weights and liver-body weight ratios of Wistar rats. The difference in liver weight between the medium-dose and high-dose groups of TCM was statistically significant （P<0.05）， and the liver-body weight ratios of the low-dose， medium-dose， and high-dose groups of TCM were all statistically significant （P<0.05）. Compared with the normal group， serum albumin and cholesterol levels increased in the medium-dose and high-dose groups of TCM （P<0.05）. The histopathology of the liver in the medium-dose and high-dose groups of TCM showed tiny vacuole-like changes. Compared with the normal group， there were obvious intestinal flora disorders after administration of Dictamni Cortex-Flavescens Sophora， and alpha diversity increased in the medium-dose and high-dose groups of TCM. The principal coordinates analysis showed that species increasingly deviated from the normal group as the administered dose increased. Compared with the normal group， the proportion of Firmicutes and Bacteroidota decreased after the drug administration， and the genus level of Parasutterella， Romboutsia， Turicibacter， Allobaculum， and Dubosiella increased. The genus level of Lachnospiraceae_NK4A136_group， Blautia， Erysipelatoclostridium， Muribaculum， and Ruminococcus_gnavus_group decreased. The correlation analysis showed that Parasutterella， Romboutsia， Turicibacter， Allobaculum， and Dubosiella were positively correlated with serum cholesterol and liver-body weight ratio， and lanchnospiraceae_NK4A136_group， Blautia， Muribaculum， Erysipelatoclostridium， and Ruminococcus_gnavus_group were negatively associated with serum cholesterol and liver-body weight ratio. ConclusionThe liver injury caused by Dictamni Cortex-Flavescens Sophora is manifested as a lipid metabolism disorder， and the mechanism is related to the increase in lipid metabolism-related microorganisms.

Progress in application of engineered microorganisms in different diseases / 国际生物医学工程杂志

The human body contains a large microbial community composed of eukaryotes, archaea, bacteria, and phages. Bacteria are the most prominent members of this community, numbering in the same order of magnitude as human cells. Many commensal or pathogenic bacteria interact with their hosts through biochemical signals. Based on these bacterial properties, commensal and attenuated pathogens have been designed to deliver therapeutic molecules to target specific diseases. The engineered bacteria or bacteria-derived particles and their encapsulation, secretion, and expression of surface therapeutic molecules developed in the past five years were introduced. Their applications in anti-inflammatory, anti-tumor, thrombosis treatment, and imaging were reviewed, and the clinical translational potential of microbial drug delivery systems was discussed.

Relationship between oral diseases and depression / 口腔疾病防治

@#Oral health is an integral component of overall well-being, with the oral cavity serving as a channel for external communication and expression of emotions such as stress and pessimism. Oral diseases can intensify feelings of depression, whereas depression can worsen oral health conditions. As a crucial part of the human microbiome, an imbalance in oral microbiota can release oral pathogenic microbes, which, through pathways including the circulation, nervous, and immune systems, can reach the brain and significantly affect the central nervous system. This can lead to dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, further intensifying the development of depression. Similarly, an imbalance in oral microbiota in individuals with depression can intensify the occurrence of oral diseases. The relationship between depression and oral diseases is not isolated but rather a complex interplay in which they mutually influence and act as causative factors. To elucidate the causal relationship between oral diseases and depression and devise strategies for the prevention and treatment of both conditions, we explore the interaction mechanisms between oral diseases and depression from the perspective of oral microbiota. The occurrence of dental caries, periapical periodontitis, and periodontal diseases is closely associated with the excessive proliferation of specific bacteria in the oral cavity, such as Streptococcus mutans, Porphyromonas gingivalis, and Fusobacterium nucleatum. These bacteria can directly invade the brain through the compromised blood-brain barrier, activating pro-inflammatory cytokines and worsening depressive symptoms. Inflammatory conditions and ulcers in the oral mucosa are caused by various factors, including infection and immune abnormalities. Because of compromised immune function in individuals with depression, these inflammatory responses are often more severe and difficult to control. Malocclusion, trigeminal neuralgia, and temporomandibular joint disorders increase the risk of depression because of psychological stress and changes in the immune system. We also outline the diagnostic and therapeutic considerations for oral diseases in patients with depression, emphasizing the importance of early intervention for disease management. Future research will explore the therapeutic potential of oral microbiota in individuals with depression, with the aim to improve symptoms and treatment outcomes by adjusting oral microbiota, thus providing novel avenues for the prevention and treatment of depression.

Study progress on monitoring technologies and health effects of air quality in urban rail transit / 环境与职业医学

With the acceleration of urbanization, urban rail transit systems have become one of the most important modes of transportation in modern cities. Urban rail transit systems operate in enclosed or semi-enclosed environments, characterized by poor air circulation and high passenger flow. During the period of high incidence of respiratory infectious diseases in autumn and winter, air quality and pathogenic microorganism monitoring in public places have attracted much attention. This article provided a detailed introduction to air pollutants and their sources related to urban rail transit, including chemical pollutants, such as particulate matter and gaseous pollutants, and microbial aerosols. Based on identified air pollutants related to urban rail transit, this paper reviewed the research progress on air quality monitoring technologies for chemical pollution factors and microbial aerosols. Finally, a summary of the health effects of chemical pollutants and microbial aerosols was provided, along with suggestions for monitoring and improving air quality tailored to the characteristics of urban rail transit systems. Through a review of previous studies, carrying out research on air quality monitoring technologies and associated health effects related to urban rail transit is of great significance and values for air quality management, urban development, and public health.

Expert consensuses on the application of nanopore sequencing technology in the detection of pathogenic micro-organisms / 中国药房

OBJECTIVE To improve the diagnosis and treatment level of critically ill infectious diseases， standardize the clinical application of nanopore sequencing and promote the sound development of the technology. METHODS Division of Therapeutic Drug Monitoring of Chinese Pharmacological Society and Expert Committee of Precision Medicine for Clinical Treatment of Guangdong Pharmaceutical Association initiated and organized multidisciplinary experts to discuss and determine the consensus writing outline by using the nominal group method， forming a preliminary consensus draft； expert consultation was performed by using Delphi method， and then experts’ opinions were analyzed and revised to form consensus. RESULTS & CONCLUSIONS Consensuses of Experts on the Application of Nanopore Sequencing Technology in the Detection of Pathogenic Microorganisms covers targeted sequencing， metagenomic sequencing and whole genome sequencing， and is standardized in terms of sample collection and storage， detection process， bioinformatics analysis and report interpretation； the recommendations are provided for the key issues.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Interaction between microplastics and microorganisms in soil environment: a review / 生物工程学报

As a widespread pollutant in the environment, research on microplastics have attracted much attention. This review systematically analyzed the interaction between microplastics and soil microorganisms based on existing literatures. Microplastics can change the structure and diversity of soil microbial communities directly or indirectly. The magnitude of these effects depends on the type, dose and shape of microplastics. Meanwhile, soil microorganisms can adapt to the changes caused by microplastics through forming surface biofilm and selecting population. This review also summarized the biodegradation mechanism of microplastics, and explored the factors affecting this process. Microorganisms will firstly colonize the surface of microplastics, and then secrete a variety of extracellular enzymes to function at specific sites, converting polymers into lower polymers or monomers. Finally, the depolymerized small molecules enter the cell for further catabolism. The factors affecting this degradation process are not only the physical and chemical properties of the microplastics, such as molecular weight, density and crystallinity, but also some biological and abiotic factors that affect the growth and metabolism of related microorganisms and the enzymatic activities. Future studies should focus on the connection with the actual environment, and develop new technologies of microplastics biodegradation to solve the problem of microplastic pollution.