Application and mechanism of nanomedicine and nanomaterials in antibacterial infection therapy / 药学学报

Antibacterial therapy is a global health issue. The antibiotic resistance is becoming an increasingly serious threat, which caused by misuse and overuse of antibacterial agents combined with the emergence of new resistance mechanism. The resulting infection treatment risk and incidence of the spread of disease, severe cases and deaths are increased in different degrees. With the extensive application of biomaterials and nanotechnology to biomedicine, extensive research has been conducted on antibacterial infection. With the specific physicochemical properties like optical, electric and magnetic and high penetration, inorganic nanomaterials can produce natural antibacterial effect. Nanomedicine can be designed to allow controlled drug release and targeting effect, thus demonstrated better antibacterial efficiency. In this review, the mechanism of antibacterial resistance is described, and the antibacterial infection research on inorganic nanomaterials, as well as nano-drug delivery system including liposomes, nanoparticles, dendrimers and biomimetic nanocarriers are summarized. Nanomaterials and nanotechnology offer promising strategies for the development of new agents that can improve efficacy on antibacterial infections and overcome antibiotic resistance potentially.

Vigilancia del consumo de antimicrobianos en 10 instituciones de salud entre 2013 y 2020 en Colombia / Antibiotic consumption surveillance in 10 health institutions between 2013 and 2020 in Colombia

INTRODUCCIÓN: El uso de antimicrobianos es el principal factor de resistencia bacteriana. OBJETIVO: Determinar el consumo de antimicrobianos en instituciones de salud de Santiago de Cali entre 2013 y 2020. MATERIAL Y MÉTODO: Se empleó la Dosis Diaria Definida por 100 camas-día. Se definieron como criterios de inclusión las instituciones que tuvieran como mínimo 9 reportes anuales y que el reporte fuese superior a 95%. En este caso quedaron incluidas 10 instituciones. RESULTADOS: El consumo en Unidades de Cuidados Intensivos (UCI) fue mayor que en servicios diferentes a UCI. Se consumió más ceftriaxona e imipenem en servicios diferentes a UCI, mientras que meropenem, piperacilina/tazobactam y vancomicina lo fueron en UCI. En servicios diferentes a UCI, dos instituciones aumentaron el consumo para ceftriaxona, ciprofloxacina y piperacilina/tazobactam y una para vancomicina, mientras que en UCI en una institución el consumo aumentó para piperacilina/tazobactam. CONCLUSIÓN: El sistema brindó herramientas de vigilancia prospectiva que mostraron necesidades de intervención en instituciones.

BACKGROUND: The use of antibiotics is the main factor of microbial resistance. Aim: To determine the consumption of antibiotics in health care institutions in Santiago de Cali between 2013 and 2020. METHODS: The methodology of the Defined Daily Dose per 100 beddays was employed. Institutions that had at least 9 annual reports and that the report is greater than 95% were defined as inclusion criteria. In this case, 10 institutions were included. RESULTS: Consumption in Intensive Care Units (ICU) was higher than in other units. Ceftriaxone and imipenem were more consumed in units other than ICU, whereas meropenem, piperacillin/tazobactam and vancomycin were more consumed in the ICU. In units other than ICU, two institutions increased the consumption of ceftriaxone, ciprofloxacin and piperacillin/tazobactam and one the consumption of vancomycin, whereas in the ICU, one institution increased the consumption of piperacillin/tazobactam. The endemic range identified that vancomycin located itself in the epidemic zone in one institution. CONCLUSION: The system provided tools for prospective surveillance that showed the need for intervention in institutions.

Preparation and antibacterial properties of Cu-ZnO-loaded dental veneering porcelain / 口腔疾病防治

Objective@#To investigate the antibacterial properties, biocompatibility and mechanical properties of Cu-ZnO-loaded dental veneering porcelain to provide an experimental basis for the development of new dental veneering porcelain. @*Methods@#Cu-ZnO nanoparticles were added to IPS E.max Ceram for restorative veneer porcelain at different mass percentages of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, and 6 wt% using ball milling in ceramic powder. A cylindrical specimen with a diameter of 20 mm and a thickness of 2 mm was prepared by high-temperature sintering. Scanning electron microscopy was used to observe the surface morphologies of nano-Cu-ZnO and the specimens. The antibacterial effect of Escherichia coli (E. coli) was quantitatively studied by the plate colony counting method. The CCK-8 method was used to evaluate in vitro the cytotoxicity of the tested piece to mouse fibroblasts (L929). Live and dead cells were observed by fluorescence microscopy. The mechanical properties of modified IPS E. Max Ceram veneering porcelain were tested by a three-point bending strength test. @* Results @# Under the scanning electron microscope, Cu-ZnO appears with a block-like structure and can be seen dispersed in the veneering porcelain. When the nano Cu-ZnO loading was 1 wt%, 2 wt%, 3 wt%, and 4 wt%, the antibacterial rates of the specimens were 24.85%, 67.94%, 96.92%, and 99.99%, respectively, and the difference between the experimental groups and the control group was statistically significant (F = 23.308,P = 0.001). The relative growth rate of each group was greater than 80% after coculture with mouse fibroblast cells (L929) for 1 day and 3 days, and there was no significant difference between the groups. The morphology of L929 cells was normal after coculture for 24 hours. With the increase in the Cu-ZnO concentration, the flexural strength of the specimen exhibited an increasing trend followed by a decreasing trend. The bending strength of the specimen loaded with 3 wt% nano Cu-ZnO reached the maximum value (84.728 ± 6.82) MPa, and there was no statistically significant difference between groups (F = 0.633,P = 0.702).@*Conclusion@#The antibacterial rate of IPS E. max Ceram veneering porcelain loaded with 3 wt% nano Cu-ZnO was more than 96% against E. coli after high-temperature sintering at 750 ℃. The bending strength reached the maximum (84.728 ± 6.82) MPa, and there was no obvious cytotoxicity.

Actividad Antibacteriana de una Resina Ortodóntica Modificada con Diferentes Concentraciones de Nanopartículas de Óxido de Cobre

RESUMEN: El objetivo del estudio fue evaluar la actividad antibacteriana de un cemento ortodóntico modificado con diferentes concentraciones de nanopartículas de óxido de cobre (NPOCu) frente a Streptococcus mutans y Lactobacillus acidophilus. Se prepararon discos de resina conteniendo concentraciones de 1 %, 0,5 %, 0,1 % y 0,05 % de NPOCu. Los discos fueron sometidos a un ensayo microbiológico de contacto directo, sobre placas Petri inoculadas con suspensiones de las cepas. Los halos de inhibición se midieron con un compás Vernier. Adicionalmente se realizó el conteo de las unidades formadoras de colonias (UFC).Se usaron discos de resina sin agregado de NPOCu como grupo control. Los resultados mostraron que las concentraciones de 1 %, 0,5 %, 0,1 % y 0,05 % de NPOCu fueron efectivas para inhibir el crecimiento de S. mutans, generando halos de inhibición promedio de 12,7 7? 0,20 mm, 10,21 ? 0,13mm, 8,45 ? 0,24 mm y 6,22 ? 0,37 mm, respectivamente. Mientras que las concentraciones del 1 %, 0,5 % y 0,1 % inhibieron el crecimiento de L. acidophilus con halos de inhibición de 11,95 ? 0,17 mm, 9,24 ? 0,14 mm y 6,21 ? 0,20 mm. Se observaron diferencias significativas cuando se comparó el efecto de las concentraciones sobre ambas cepas (p < 0,05). Adicionalmente, todas las concentraciones de NPOCu mostraron un conteo de UFC significativamente menor que el grupo control, para ambas cepas (p < 0,05). Como conclusión podemos señalar que la incorporación de diferentes concentraciones de nanopartículas de óxido de cobre en un cemento ortodóntico posee un importante efecto antibacteriano frente a S. mutans y L. acidophilus.

ABSTRACT: The objective of the study was to evaluate the antibacterial activity of an orthodontic cement modified with different concentrations of copper oxide nanoparticles (CuONP) against Streptococcus mutans and Lactobacillus acidophilus. Resin discs containing concentrations of 1%, 0.5%, 0.01% and 0.05% of CuONP were prepared. The disks were subjected to a direct contact microbiological test on Petri dishes inoculated with suspensions of the strains. Inhibition halos were measured with a Vernier compass. Additionally, the colony forming units (CFU) were counted. Resin discs without CuONP were used as a control group. The results showed that the concentrations of 1%, 0.5%, 0.01% and 0.05% of CuONP were effective in inhibiting the growth of S. mutans, generating average inhibition halos of 12.77 ? 0.20 mm, 10.21 ? 0.13 mm, 8.45 ? 0.24 mm and 6.22 ? 0.37 mm respectively. While the concentrations of 1%, 0.5% and 0.01% inhibited the growth of L. acidophilus with inhibition halos of 11.95 ? 0.17 mm, 9.24 ? 0.14 mm and 6.21 ? 0.20 mm. Significant differences were observed when the effect of the concentrations on both strains was compared (p<0.05). Additionally, all CuONP concentrations showed a CFU count significantly lower than the control group, for both strains (p<0.05). In conclusion, we can point out that the incorporation of different concentrations of copper oxide nanoparticles in orthodontic cement has an important antibacterial effect against S. mutans and L. acidophilus.

Actividad antibacteriana de un extracto etanólico de propóleo peruano frente a Streptococcus mutans / Antibacterial activity of a Peruvian propolis ethanolic extract against Streptococcus mutans

Introducción: Los derivados del propóleo poseen propiedades antimicrobianas importantes y presentan un potencial uso para la prevención y tratamiento de la caries dental. Objetivo: Evaluar la actividad antibacteriana de un extracto etanólico de propóleo peruano frente a Streptococcus mutans. Métodos: Se obtuvo el extracto etanólico de propóleo por maceración en alcohol al 70 por ciento durante 15 días. El extracto etanólico de propóleo fue diluido con agua destilada para obtener concentraciones de 75 por ciento, 50 por ciento y 25 por ciento. La actividad antibacteriana se evaluó mediante la prueba de difusión en disco sobre medio agar cerebro-corazón inoculado con S. mutans ATCC® 25175™, se empleó clorhexidina (CHX) al 0,12 por ciento como control. Las placas de Petri fueron incubadas por 48 horas a 37 ºC en condiciones de microaerofilia. Posteriormente se realizó la medición de los halos de inhibición con un compás Vernier. Resultados: Todas las concentraciones del extracto etanólico de propóleo presentaron actividad antibacteriana frente al S. mutans (25 por ciento = 17,582 ± 2,578 mm; 50 por ciento = 16,906 ± 1,892 mm; 75 por ciento = 16,881 ± 2,013 mm; 100 por ciento = 17,201 ± 1,305 mm). Sin embargo, fueron menores que la CHX al 0,12 por ciento (24,543 ± 2,486 mm) (p < 0,05). Según la escala de Duraffourd, S. mutans fue sensible (+) y muy sensible (++) para todas las concentraciones del extracto etanólico de propóleo, mientras que para CHX al 0,12 % fue sumamente sensible (+++) (p < 0,05). Conclusiones: El extracto etanólico de propóleo peruano presenta actividad antibacteriana significativa considerada como sensible y muy sensible frente a S. mutans(AU)

Introduction: Due to their important antimicrobial properties, propolis by-products are potentially useful for the prevention and treatment of dental caries. Objective: Evaluate the antibacterial activity of a Peruvian propolis ethanolic extract against Streptococcus mutans. Methods: The propolis ethanolic extract was obtained by maceration in 70 percent alcohol for 15 days. The extract was diluted in distilled water to obtain concentrations of 75 percent , 50 percent and 25 percent . Antibacterial activity was evaluated by the disk diffusion test in brain heart agar medium inoculated with S. mutans ATCC® 25175™. Chlorhexidine (CHX) 0.12 percent was used as control. The Petri plates were incubated for 48 hours at 37ºC in microaerophilic conditions. The inhibition haloes were then measured with a Vernier caliper. Results: All the concentrations of the propolis ethanolic extract displayed antibacterial activity against S. mutans: 25 percent = 17.582 ± 2.578 mm; 50 percent = 16.906 ± 1.892 mm; 75 percent = 16.881 ± 2.013 mm; 100 percent = 17.201 ± 1.305 mm. However, values were lower than those of 0.12 percent CHX: 24.543 ± 2.486 mm (p < 0.05). According to the Duraffourd scale, S. mutans was sensitive (+) and very sensitive (++) to all propolis ethanolic extract concentrations, and highly sensitive to 0.12 percent chlorhexidine (+++) (p < 0.05). Conclusions: The Peruvian propolis ethanolic extract displays significant antibacterial activity against S. mutans. Such activity was evaluated as sensitive and very sensitive(AU)

Caracterización Química y Actividad Antibacteriana in vitro de un Extracto Etanólico de Propóleo Peruano Frente a Streptococcus mutans

RESUMEN: El objetivo del estudio fue caracterizar químicamente un extracto etanólico de propóleo peruano y evaluar su actividad antibacteriana frente a Streptococcus mutans. (S. mutans). Se obtuvo el extracto etanólico de propóleo (EEP) por maceración en alcohol al 70 % durante 15 días, el EEP fue sometido a cromatografía en capa fina para identificar sus componentes químicos. El EEP fue diluido con agua destilada para obtener concentraciones de 75 %, 50 % y 25 %. La actividad antibacteriana se realizó mediante la prueba de difusión en disco sobre medio Brain Heart infusion agar(BHA) inoculado con S. mutans ATCC® 25175™, se empleó clorhexidina (CHX) al 0,12 % como control positivo. Las placas fueron incubadas por 48 horas a 37ºC en condiciones de microaerofilia. Posteriormente se realizó la medición de los halos de inhibición con un compás Vernier. Los resultados mostraro n que el EEP presenta como principales componentes terpenos, diterpenos y terpenoidales. Todas las concentraciones del EEP presentaron actividad antibacteriana frente al S. mutans (25 %= 17,582 ± 2,578 mm; 50 % = 16,906 ± 1,892 mm; 75 % = 16,881 ± 2,013 mm; 100 % = 17,201 ± 1,305 mm); sin embargo, fueron menores al compararlos con CHX al 0,12 % (24,543 ± 2,486 mm) (p<0,05). Según la escala de Duraffourd, S. mutans fue sensible (+) y muy sensible (++) para todas las concentraciones del EEP, mientras que para CHX al 0,12 % fue sumamente sensible (+++) (p<0,05). Como conclusión, las diversas concentraciones de EEP peruano presentan actividad antibacteriana significativa considerada como sensible y muy sensible frente a S. mutans.

ABSTRACT: The objective of the study was to chemically characterize an ethanolic extract of Peruvian propolis and evaluate its antibacterial activity against Streptococcus mutans. (S. mutans). The ethanolic extract of propolis (EEP) was obtained by maceration in 70 % alcohol for 15 days, the EEP was subjected to thin layer chromatography to identify its chemical components. The EEP was diluted with distilled water to obtain concentrations of 75%, 50 % and 25 %. The antibacterial activity was performed by the disk diffusion test on Brain Heart infusion agar (BHA) medium inoculated with S. mutans ATCC® 25175 ™, 0.12 % chlorhexidine (CHX) was used as a positive control. Plates were incubated for 48 hours at 37°C under microaerophilic conditions. Subsequently, the inhibition halos were measured with a Vernier compass. The results showed that the EEP presents as main components terpenes, di-terpenes and terpenoidals. All concentrations of the EEP showed antibacterial activity against S. mutans (25 % = 17,582 ± 2,578 mm; 50 % = 16,906 ± 1,892 mm; 75 % = 16,881 ± 2,013 mm; 100 % = 17,201 ± 1,305 mm); however, they were lower when compared with 0.12 % CHX (24,543 ± 2,486 mm) (p <0.05). According to the Duraffourd´ scale, S. mutans was sensitive (+) and very sensitive (++) for all EEP concentrations, while for 0.12 % CHX it was highly sensitive (+++) (p < 0.05). In conclusion, all concentrations of Peruvian EEP have significant antibacterial activity considered as sensitive and very sensitive against S. mutans.

Triclosan exposure to pregnant women and its association with birth outcomes / 上海预防医学

Triclosan(TCS)is a broad-spectrum antibacterial agent that is widely used in personal care products. Humans are exposed to these chemicals through oral intake or direct dermal absorption. The main way to eliminate TCS is through urine. Studies have shown that TCS may interfere with thyroid function and the reproductive endocrine system. In recent years, increasing epidemiological studies have focused on TCS exposure during pregnancy and the relationship between TCS exposure and birth outcomes. Compared with other countries and regions, pregnant women have lower levels of TCS exposure in China. Animal experiments suggested that high dose of TCS exposure during pregnancy may affect birth outcomes through its endocrine disruption. This review is aimed to summarize the effects of TCS exposure during pregnancy on the birth outcomes.

Research progress on the antibacterial properties of dental resin materials / 口腔疾病防治

@#Dental resin materials have been widely used in the treatment of dental defects. However, the polymerization shrinkage of the resin materials tends to cause microleakage and accumulation of bacterial plaque, which leads to secondary dental caries. Endowing dental resin with antibacterial properties is an important way to solve this problem. Adding antibacterial agents to dental resin is the main method to give it antibacterial properties. Antimicrobial agents are mainly divided into three types: release type, non-release type and mixed type. In terms of antibacterial effects, the selection and addition of antibacterial agents will affect the antibacterial and mechanical properties of dental resin materials; and the long-term antibacterial effect of antimicrobial agents in the oral cavity remains to be verified; as antimicrobial agents or other environmental factors can lead to drug resistance and even dormant persistent bacteria. In recent years, researchers have been committed to improving the antibacterial effect by modifying antibacterial agents. The sustained release of antimicrobial agents via carriers is also the main research direction. This paper reviews the research progress on the antibacterial properties of dental resin materials.

Chemical composition and in vitro antibacterial activity of essential oils from Murraya paniculata (L. ) Jack (Rutaceae) ripe and unripe fruits against bacterial genera Mycobacterium and Streptococcus

This study aims to investigate chemical composition of essential oils from Murraya paniculata (L.) Jack (Rutaceae) ripe and unripe fruits and determine their in vitro antibacterial activity. Essential oils were extracted by hydrodistillation from Murraya paniculata (L.) Jack ripe and unripe fruits collected in the Cerrado, in Rio Verde, southwestern Goiás, Brazil. They were analyzed by gas chromatography with flame ionization detector (GC-FID) and by gas chromatography-mass spectrometry (GC-MS). Sesquiterpenes, which represent the most abundant class of compounds in oils, predominated in both ripe and unripe fruits. Major constituents of essential oils extracted from ripe fruits (RF-EO) were (-caryophyllene (21.3%), (-ylangene (13.3%), germacrene-D (10.9%) and (-zingiberene (9.7%) whereas the ones of unripe fruits (UF-EO) were sesquithujene (25.0%), (-zingiberene (18.2%), germacrene-D (13.1%) and (-copaene (12.7%). In vitro antibacterial activity of essential oils was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method in 96-well microplates. Both essential oils under investigation showed moderate anti-streptococcal activity against the following bacteria: Streptococcus mutans, S. mitis, S. sanguinis, S. sobrinus and S. salivarius. MIC values ranged between 100 and 400 µg/mL. Regarding the antimycobacterial activity, essential oils from M. paniculata (L.) Jack unripe and ripe fruits were active against Mycobacterium kansasii (MIC = 250 µg/mL), moderately active against M. tuberculosis (MIC = 500 µg/mL) and inactive against M. avium (MIC = 2000 µg/mL). This study was pioneer in revealing similar chemical profiles of both essential oils extracted from Murraya paniculata (L.) Jack unripe and ripe fruits, besides describing their in vitro anti-streptococcal and antimycobacterial activities.

Antibacterial Activity of Polygonum Orientale Extracts Against Clavibacter Michiganensis subsp. michiganensis, the Agent of Bacterial Canker of Tomato Disease

Abstract Clavibacter michiganensis subsp. michiganensis (Cmm), which is a Gram positive bacterium, causes the bacterial canker of tomato disease. The purpose of the study was to evaluate the antibacterial activity of Polygonum orientale extracts against Cmm. In this study, firstly, effects of three extracting parameters (extractive time, extractive temperature, and solid to liquid ratio) of orthogonal experiment design L27 (313) were conducted. Secondly, survival rate was determined and inhibition zone of Cmm rescued post-stress was monitored. Finally, extracellular OD260nm value, extracellular protein content, conformational structure of membrane protein, extracellular alkaline phosphatase (AKP) activity, and ATPase activity were measured to investigate the antibacterial mechanism. Results of orthogonal experiment revealed that extractive time and extractive temperature had highly significant (P<0.01) effects on the antibacterial activity of P. orientale extracts. The optimum conditions were as follows: 10h of extractive time, 60°C of extractive temperature, and 1:20 (g:mL) of solid to liquid ratio. This study also demonstrated that the living cells of each sample from survival rate test had almost no resistance or adaptability, and rescued Cmm cells were much easier to be inhibited by P. orientale extracts. The results of antibacterial mechanism indicated that cell membrane and cell wall of Cmm were seriously damaged by P. orientale extracts, and P. orientale extracts reduced the intracellular ATPase activity dramatically. All these findings suggested that P. orientale extracts had a strong antibacterial activity to inhibit Cmm, and could be used for the ecological management of the bacterial canker of tomato disease.

Antibiotic sensitivity pattern of bacterial isolates in patients with chronic rhinosinusitis in Kaduna, Nigeria

Introduction: A common practice in the management of patients with chronic rhinosinusitis (CRS), the empirical use of antibiotics may contribute to treatment failure and to the development of antimicrobial resistance. Objective: To determine the antibiotic sensitivity pattern of aerobic and anaerobic bacteria associated with CRS. Methods: This was a prospective cross-sectional study in which endoscopically guided middlemeatal swabs (IBMSpss, version 16.0, Chicago, IL, USA) were aseptically taken from patients diagnosed with CRS after obtaining informed consent and ethical clearance. The samples were sent to the laboratory for qualitative and semiquantitative analysis via gram stain, aerobic, anaerobic cultures and antibacterial sensitivity tests. The collected data was analyzed using SPSS for Windows, version 16 (SPSS Inc, Chicago, IL, USA). Simple statistical parameters and paired sample t-test were used, as appropriate. Results: There were 74 (56.92%) bacterial growths, out of which 55 (74.32%) were aerobic and 19 (25.68%) were anaerobic isolates, from a total of 130 patients. About 13 (17.5%- 18%) of these bacterial growths yielded a mixed growth of aerobic and anaerobic isolates. Themost common bacterial isolates were 26 (35.14%) Staphylococcus aureus, Haemophilus influenzae 9 (12.16%), Streptococcus viridians 8 (10.81%), and Streptococcus pneumoniae 5 (6.76%). Augmentin, ciprofloxacin, and Peflacine were found to bemost effective, followed by levofloxacin, Rocephin, erythromycin and Zinat in that order (AU)

Clinical characteristics and pathogen profile in 193 cases of community acquired bloodstream infection / 中国感染与化疗杂志

Objective To understand the clinical and pathogen characteristics of community acquired bloodstream infection(CABSI)for improving empirical antimicrobial therapy. Methods The clinical and laboratory findings of 193 CABSI cases in the Fifth Affiliated(Zhuhai)Hospital of Zunyi Medical College from 2013 to 2017 were retrospectively analyzed. Results Of the193 CABSI cases, 97.9％(189/193)had underlying diseases and/or risk factors. Primary site of infection was identified in 81.3％(157/193)of the patients. The top three primary site of infection was urinary tract(39.5％, 62/157), hepatobiliary system(22.9％, 36/157)and lower respiratory tract(20.4％, 32/157). The top pathogens included Escherichia coli(47.2％), Klebsiella pneumoniae(15.0％), coagulase-negative Staphylococcus(10.4％), and Streptococcus spp.(7.8％). All the E. coli and K. pneumoniae strains were susceptible to carbapenems. More than 90％ of the E. coli and K. pneumoniae strains were susceptible to piperacillin-tazobactam and amikacin. About 54.9％(50/91)of the E. coli and 27.6％(8/29)of the K. pneumoniae strains produced extended-spectrum β-lactamases(ESBLs). No vancomycin-resistant gram-positive bacteria were detected. The prevalence of MRCNS and MRSA was 35.0％ and 0, respectively. Conclusions Most CABSI cases had underlying diseases and/or risk factors. The common primary site of infection associated with secondary bloodstream infection is urinary tract, hepatobiliary system, and lower respirtaory tract. Enterobacteriaceae strains are the main pathogen of CABSI.

Estudio in vitro del Efecto Antibacteriano de la Oleorresina de Copaifera reticulata y el Aceite Esencial de Origanum majoricum Frente a Streptococcus mutans y Enterococcus Faecalis Bacterias de Importancia en Patologías Orales / In vitro Study of the Antibacterial Effect of Oleoresin of Copaifera reticulata and the Essential Oil of Origanum majoricum against Streptococcus mutans and Enterococcus faecalis Bacteria of Importance in Oral Pathologies

RESUMEN: El objetivo del estudio fue determinar el efecto antibacteriano in vitro de la oleorresina de Copaifera reticulata (C. reticulata) "copaiba" y del aceite esencial de Oreganum majoricum (O. majoricum) "orégano" frente a Streptococcus mutans (S. mutans) y Enterococcus faecalis (E. faecalis). Se desarrollaron pruebas de sensibilidad activando primero las cepas bacterias a enfrentar. La oleorresina de copaiba fue diluida con dimetilsulfósido (DMSO), obteniéndose al final concentraciones a probar de 100 %, 50 %, 25 %, y 12,5 %. En relación al aceite esencial de orégano este se probó solamente al 100 %. Para la prueba de difusión en agar con discos, se tomaron inóculos 100 µL de cada cepa bacteriana a una turbidez de 0,5 de Mc Farlam, para ser sembrados por diseminación en placas de tripticasa soya agar, para luego colocar los discos de forma equidistante cargados con las diferentes concentraciones de los productos naturales, se utilizaron como control positivo a la clorhexidina al 0,12 % y al DMSO como control negativo. Se incubaron las placas por el método de la vela en extinción a 37 °C, por un periodo de 24 horas, pasado el tiempo se realizó la lectura de los halos de inhibición. Los resultados obtenidos por la copaiba, determinaron un efecto antibacteriano en sus cuatro concentraciones, siendo los mayores halos de inhibición a la concentración del 100 %, copaiba genero mayores halos promedios para S, mutans de 30,00 ± 0,00 mm y para E. faecalis de 8,3 ± 0,50 mm. Para el caso del orégano se producen halos a la concentración del 100 % con un promedio de 25,3 ± 0,96 mm para S. mutans y para E. faecalis de 9,5 ± 1,29 mm. Se concluye del estudio que tanto copaiba como el orégano presentan un efecto antibacteriano para ambas bacterias, siendo su mayor efecto antibacteriano para ambos productos naturales sobre S. mutans.

ABSTRACT: The objective of the study was to determine the in vitro antibacterial effect of the oleoresin of Copaifera reticulata (C. reticulata) "copaiba" and of the essential oil of Oreganum majoricum (O. majoricum) "oregano" against Streptococcus mutans (S. mutans) and Enterococcus faecalis (E. faecalis). Sensitivity tests were developed by first activating the bacteria strains to be confronted. The oleoresin of copaiba was diluted with dimethylsulphoside (DMSO), obtaining final concentrations to be tested of 100 %, 50 %, 25 %, and 12.5 %. In relation to the essential oil of oregano, it was only 100 % tested. For the disk agar diffusion test, 100 mL of each bacterial strain was taken at a turbidity of 0.5 of Mc Farlam, to be planted by dissecting trypticase soy agar plates, and then placing the disks equidistantly loaded with the different concentrations of natural products; 0.12 % chlorhexidine was used as a positive control and DMSO as negative control. The plates were incubated by the candle method in extinction at 37 °C, for a period of 24 hours, after which time the inhibition halos were read. The results obtained by the copaiba, determined an antibacterial effect in its four concentrations, being the biggest halos of inhibition at the concentration of 100 %, copaiba genus higher average halos for S. mutans of 30.00 ± 0.00 mm and for E. faecalis of 8.3 ± 0.50 mm. In the case of oregano, haloes are produced at a concentration of 100 % with an average of 25.3 ± 0.96 mm for S. mutans and for E. faecalis 9.5 ± 1.29 mm. It is concluded from the study that both copaiba and oregano present an antibacterial effect for both bacteria, being its greater antibacterial effect for both natural products on S. mutans.

Effectiveness analysis and inspirations of rational administration of carbapenem / 中华医院管理杂志

The hospital introduced a multi-department synergy in management of the rational use of carbapenems. Specifically,the medical affairs department conducts training and appraisal of doctors along with a monthly checkup of medical records. The pharmaceutical affairs division conducts prior prescriptions checkup and follow-up comment. The clinical microbiology laboratory and the hospital-acquired infection management department monitors and releases such infection and bacterial resistance information of the whole hospital in real time. The results showed increased prescriptions of imipenem and cilastatin sodium, and decreased prescriptions of biapenem for injection. Drug resistance analysis showed that carbapenem resistant strains increased by 28%,but the total number of patients reduced by 10% and total number of patients with multidrug resistance remained unchanged. It is proposed to further antimicrobial stewardship in the hospital to achieve rational drug use and curb bacterial resistance.

Minimum inhibitory concentration and minimum bactericidal concentration of antibacterial fluoride varnish / 대한치과재료학회지

The aim of this study was to investigate the antibacterial effect of fluoride varnish with antibacterial agents on Streptococcus mutans (S. mutans). Experimental fluoride varnish (EFV) with 5% NaF was fabricated. Five antibacterial agents were tested with 1 mM and 10 mM concentrations, respectively: Bakuchiol (BAK), Bavachalcone (BCC), Isobavachromene (IBC), and Bavachromene (BCM). MIC and MBC test was performed by antibacterial agents with and without EFV using 1.1 × 10¹⁰ CFU/ml of S. mutans. Cell viability test were performed using MTT test. Statistical analysis was done with ANOVA and Duncan's multiple range test at α=0.05. In the antibacterial agents without EFV, the MIC of BAK, BCC, and IBC was the lowest (0.015 mM), and the MBC of BAK was the lowest (0.031 mM). For the antibacterial agents with EFV, the MIC (0.031 mM) and MBC (0.062 mM) of BAK was the lowest, respectively. In MTT test, 1 mM BCM showed the highest cell viability (P < 0.05). This study suggest that BAK can be applied the fluoride varnish under the control of the concentration to develop antibacterial fluoride varnish.

Effects of room curing polymethyl methacrylate with nano-silver on liver tissue and DNA damage of hepatic cells in mice / 吉林大学学报(医学版)

Objective: To study the effects of room curing polymethyl methacrylate (PMMA) with nano-silver on the liver tissue and DNA damage of hepatic cells in the mice, and to evaluate the hepatotoxicity of the nanocomposites. Methods: A total of 40 male Kunming mice aged 6-8 weeks were divided into room curing PMMA with nano-silver groups (PMMA-NM groups, 72 h extract liquid, 1/2 72 h extract liquid, 1/4 72 h extract liquid), room curing PMMA groups (PMMA groups, 72 h extract liquid, 1/2 72 h extract liquid, 1/4 72 h extract liquid), negative control group, and positive control group (n=5). All mice were treated by gavage with test compounds at the beginning of experiment and 24 h and 45 h after experiment except the positive control agent, the mice in positive control group were treated with ethylmethylsulfone at 24 and 45 h after experiment, and the mice in negative control group were administrated with the same volume of normal saline by gavage. The eyeball blood of mice was collected for biochemistry analysis of liver 3 h after the final administration. The liver tissue was completely removed immediately after the mice were sacrificed and the organ coefficient was calculated. The percentage of tail DNA (%tail DNA), tail length (TL) and Olive tail moment (OTM) were detected by the in vivo comet assay, and the images were analyzed with analysis software of comet assay. Results: Compared with negative control group, the liver coefficient, the alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in liver tissue of the mice in various experimental groups had no significant differences (P>0. 05); the % tail DNA, TL and OTM in PMMA-NM groups and PMMA groups had no significant differeces (P>0. 05). The % tail DNA, TL and OTM of the mice in positive control group were higher than those in negative control group (t= -40. 911, P0. 05). There were no significant differences of the % tail DNA, TL and OTM between PMMA-NM groups at different concentrations of extrat liquid (P>0. 05). Conclusion: Room curing PMMA with nano-silver doesn't have adverse effects on the liver and its function in the mice, and the results of comet assay indicates that the material has no genotoxicity, showing that the composite has good biocompatibility.

Antimicrobial resistance profile of the gram-negative bacilli isolated from urinary tract infections / 中国感染与化疗杂志

Objective? To?investigate?the?antimicrobial?resistance?and?beta-lactamase?production?profile?in?the?gram-negative?bacilli?isolated from urinary tract infections in the Second People's Hospital of Gansu Province during the period from 2014 to 2015. The results will provided to clinicians for better antimicrobial treatment. Methods? The?bacterial?isolates?were?identified?via?conventional?laboratory?tests?or?automatic?identification?systems?and?subjected?to?antimicrobial?susceptibility?testing?by?using?Kirby-Bauer?method.?Three-dimensional test was used to detect the enzymes conferring antimicrobial resistance. The susceptibility testing results were interpreted according to the CLSI breakpoints issued in 2012. Results A total of 987 gram-negative strains were isolated from urinary tract infections, including E. coli (51.6%, 509/987), Enterobacter (11.0%, 109/987), P. aeruginosa (10.5%, 104/987), K. pneumoniae (9.9%, 98/987), P. mirabilis (9.3%, 92/987), C. freundii (4.7%, 46/987), and other gram-negative bacilli (2.9%, 29/987). ESBLs were produced?in?494?(50.1?%)?of?the?987?strains?of?gram?negative?bacilli.?Preliminary?screening?test?identified?243?AmpC?beta-lactamases?producing?strains,?and?135?(13.7?%)?strains?were?confirmed?by?three-dimensional?test.?Both?ESBLs?and?Amps?beta-lactamases?were?produced in 16 (1.6%) strains. The prevalence of ESBLs-producing strains was 79.6% in E. coli, 34.6% in P. aeruginosa and 37.8% in K. pneumoniae?isolates.?Metallo-β-lactamase?or?KPC?beta-lactamase?was?not?identified.?The?antimicrobial?resistance?was?serious?in?gram-negative bacilli, which showed relatively low resistance rate to imipenem (0.02%), amikacin (10.6%), cefoperazone-sulbactam (23.8 %), and nitrofurantoin (25.2 %). E. coli prevalence of levofloxacin,?ciprofloxacin?resistance?respectively?were?89.8%,?91.8%. The gram-negative bacilli from urinary tract also showed various levels of resistance to cephalosporins. Conclusions The gram-negative bacilli isolated from urinary tract infections are mainly E. coli. The gram-negative isolates show high level antimicrobial resistance and high prevalence of beta-lactamases. Imipenem, amikacin, cefoperazone-sulbactam, and nitrofurantoin still have very high antibacterial activity against these isolates in vitro.

Antibacterial and antioxidant activities of methanolic leaf extract of Maerua crassifolia.

The objective of this study was to investigate the antibacterial and antioxidant activities of the methanol leaf extract of Maerua crassifolia, an important medicinal plant used in Nigeria. The antibacterial properties of the methanol extract were studied against clinically important bacteria viz; Staphylococcus aureus, Shigella spp., Salmonella typhi, Bacillus subtilis and Escherichia coli by disc diffusion method. The free radical scavenging potential of the extract was assessed by measuring its capability for scavenging 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical. The methanol leaf extract of Maerua crassifolia at the concentration of 12.5-150 μg/ml, showed significant activity against all the tested organisms. The observed antioxidant activity of the leaf extract suggests that the extract is a potential source of natural antioxidant and could be useful in the treatment of diseases.

Clinical analysis of 13 cases of Listeria septicemia / 中国感染与化疗杂志

Objective To analyze the clinical characteristics of patients with L isteria septicemia for better clinical diagnosis and management of the disease .Methods A retrospective study was carried out in 13 patients with confirmed diagnosis of Listeria septicemia from July 2009 to November 2013 in West China Hospital of Sichuan University .The clinical features ,laboratory tests ,treatments and clinical outcomes were reviewed and analyzed . Results The vast majority of the 13 patients were immunocompromised or with critical organ dysfunction . The in vitro antimicrobial susceptibility testing indicated that penicillin ,ampicillin and levofloxacin were the most active agents against Listeria ,followed by imipenem ,erythromycin , ciprofloxacin and tetracycline .Only 33 .3% of the 13 Listeria isolates were sensitive to oxacillin .Eight patients were cured ,2 improved ,2 died after therapy .The remaining one patient gave up therapy .Conclusions The incidence of Listeria septicemia was associated with advanced age and presence of underlying diseases .Early etiology diagnosis and appropriate antibacterial therapy can improve the outcome of such patients .Actively treating underlying diseases helps reduce the mortality rate .

Distribution and antibiotic resistance profile of nonfermentative gram negative bacteria / 中国感染与化疗杂志

Objective To investigate the clinical distribution and antibiotic resistance of the nonfermenting bacterial strains isolated in Beijing Anzhen Hospital from 2008 to 2012.Methods The bacteria were identified by VITEK-compact system and Phoenix 100 system. Antimicrobial susceptibiity was tested by dilution method. Results A total of 2 450 strains of nonfermentative gram-negative bacteria were isolated from clinical specimens. Acinetobacter baumannii, Pseudomonas aeruginosa and Stenotrophomonas maltophilia accounted for 57.2%,25.5% and 10.0%.Specimens were mostly collected from respiratory tract (80.9%),followed by blood (8.1%)and wound exudates (3.9%).The strains were mainly collectd from ICU (50.0%),cardiac surgery ward (17.0%)and respiratory medical ward (11.5%).The prevalence of imipenem-resistant A.baumannii was 62.3%,79.2%,70.4%,76.1%,67.8% from 2008 to 2012.The prevalence of imipenem-resistant P.aeruginosa was 28.7%,25.0%,27.6%,31.1% and 32.0%.S.maltophilia strains showed the highest susceptibility to trimethoprim-sulfamethoxazole and levofloxacin.Conclusions The high prevalence of antibiotic-resistant non-fermenting bacteria poses a great challenge to clinicins. The rational treatment choice should be based on the result of suseptibility testing.