Susceptibility of Mixed Infection of Ureaplasma Urealyticum and Mycoplasma Hominis to Seven Antimicrobial Agents and Comparison with that of Ureaplasma Urealyticum Infection

In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum (UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with that of UU infection in NGU patients, the in vitro susceptibility was determined by using microdilution method. The positive results were analyzed. The results showed that the sequence of susceptibility to 7 kinds of antimicrobial agents for both UU infection group and UU-MH mixed infection group was almost the same from the highest susceptibility to the lowest accordingly: Josamycin, Doxycycline, Minocycline, Sparfloxacin, Roxithromycin, Ofloxacin and Azithromycin. The total drug resistance rate for UU-MH mixed infection group (97. 67 %) was significantly higher than that for UU infection group (44. 67 %, P<.0. 01). The highest drug resistance rate in UU group and UU-MH mixed infection group was 31. 33 % (Ofloxacin) and 90. 48 % (Azithromycin) respectively. UU-MH mixed infection showed an increased drug resistance and changes of drug resistance spectrum.

Pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma in vitro

AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metronidazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.

Evaluation of rational use of antimicrobial agents in a Brazilian intensive care unit

The present study sought to assess the rational use of antimicrobial agents in a Brazilian intensive care unit (ICU) and its association with antimicrobial resistance in elderly patients admitted to the unit. Results: Choice of empiric and sensitivity-guided therapy was inadequate in > 80% and 59% of cases respectively. Inadequate antimicrobial therapy, whether empiric or sensitivity-guided, was positively correlated with bacterial resistance (r = 0.316;p = 0.001). Sensitivity testing revealed a 46.5% resistance rate to eight out of the ten most commonly used antibiotics. Multiple drug-resistant organisms were found in 40.8% of patients. A significant increase was observed in the number of multidrug-resistant samples between 2006/2007 and 2008 (r = 0.41, p = 0.006), (r = 0.598, p = 0.001), (r = 0.688, p = 0.00). Conclusion: We found a high rate of antibiotic misuse in the study sample. Inadequate therapy was correlated with resistance to antimicrobial agents.

Effects of water-aging for 6 months on the durability of a novel antimicrobial and protein-repellent dental bonding agent

Biofilms at the tooth-restoration bonded interface can produce acids and cause recurrent caries. Recurrent caries is a primary reason for restoration failures. The objectives of this study were to synthesize a novel bioactive dental bonding agent containing dimethylaminohexadecyl methacrylate(DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine(MPC) to inhibit biofilm formation at the tooth-restoration margin and to investigate the effects of water-aging for 6 months on the dentin bond strength and protein-repellent and antibacterial durability. A protein-repellent agent(MPC) and antibacterial agent(DMAHDM) were added to a Scotchbond multi-purpose(SBMP) primer and adhesive. Specimens were stored in water at 37 °C for 1, 30, 90, or 180 days(d).At the end of each time period, the dentin bond strength and protein-repellent and antibacterial properties were evaluated. Protein attachment onto resin specimens was measured by the micro-bicinchoninic acid approach. A dental plaque microcosm biofilm model was used to test the biofilm response. The SBMP + MPC + DMAHDM group showed no decline in dentin bond strength after water-aging for 6 months, which was significantly higher than that of the control(P < 0.05). The SBMP + MPC + DMAHDM group had protein adhesion that was only 1/20 of that of the SBMP control(P < 0.05). Incorporation of MPC and DMAHDM into SBMP provided a synergistic effect on biofilm reduction. The antibacterial effect and resistance to protein adsorption exhibited no decrease from 1 to 180 d(P > 0.1). In conclusion, a bonding agent with MPC and DMAHDM achieved a durable dentin bond strength and long-term resistance to proteins and oral bacteria. The novel dental bonding agent is promising for applications in preventive and restorative dentistry to reduce biofilm formation at the tooth-restoration margin.

The Antimicrobial Activity of Wool Fabrics Treated with Crosslinking Agents and Polyhexamethylene Biguanide

In this study,we used citric acid(CA)as a crosslinking agent,mixed with polyhexamethylene biguanide,to perform a pad-dry-cure treatment on wool fabrics to study its antimicrobial effects and physical properties.

Synthesis and Antimicrobial Properties of the Novel Fluonnated Bis-ammonium Salts with Two Primary Amine Groups

In order to resolve the increasing resistance phenomena of the Gram-negative bacteria against single chain quaternary ammonium salts （QAS）, lysine with a pedant fluorinated bis-ammonium salts was synthesized and its antimicrobial properties were evaluated in this work. The novel fluorinated bis-ammonium salts shows similar activity with conventional single chain quaternary ammonium salts against Gram-positive bacteria but stronger activity against Gram-negative bacteria and yeast compared with the single chained counterpart.

Antimicrobial and Antioxidant Activity of Anacardium occidentale L. Flowers in Comparison to Bark and Leaves Extracts

Anacardium occidentale L., Anacardiaceae, is frequently used to treat infections. We evaluated the antimicrobial and antioxidant activity of extracts obtained from aerial parts of the plant in comparison with the extract prepared with the flowers. Ethanol extracts of the leaves (EEL), stem bark (EEB), and flowers (EEF) were prepared separately. The antimicrobial activity was evaluated by agar diffusion and broth dilution methods. The minimum bactericidal and fungicidal concentrations were determined against: Streptococcus mutans, Lactobacillus acidophilus, Staphylococcus aureus, MRSA, Enterococcus faecalis, Streptococcus pyogenes, Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae, Helicobacter pylori, Salmonella choleraesuis, Candida albicans, and Candida tropicalis. The antioxidant activity of the extracts was evaluated based on their scavenger capacity of 2,2-diphenyl-1-picrylhydrazyle. The phytochemical profile was analyzed by colorimetric methods and by HPLC with UV detection. All extracts exhibited antioxidant and antimicrobial activity. Although, the EEF was the most effective since it inhibited the growth of all 14 microorganisms tested. Anacardic and galic acids were identified in all extracts as well phenolic compounds, triterpenes, flavones and xanthones. In conclusion, the extracts obtained from the aerial parts of A. occidentale, mainly the extract of flowers that was the most effective, are rich in bioactive metabolites that exert a potent antioxidant and antimicrobial effect. Taken together, the results indicate an important biotechnological potential of A. occidentale as a source of compounds with broad-spectrum antimicrobial and of antioxidant activity to be used in the food and cosmetics industry.

Effectiveness of Disinfection in Bacteriology Laboratories in Togo, 2021

Background: Laboratory personnel is at risk of biological contamination leading to laboratory-acquired infections (LAIs). The use of disinfection products is essential in the prevention of these infections. This work aimed to evaluate the effectiveness of antimicrobial agents used in disinfection in bacteriology laboratories in Togo. Methods: This was a cross-sectional study conducted from June to December 2021 in all bacteriology laboratories in Togo. Swabs taken before and after disinfection of surfaces and staff hands were immediately plated on agar media. Counting and identification of isolated colonies were done after 24 hours of incubation. The ANOVA test was used to compare calculated means, prevalence ratio (PR) and 95% confidence intervals (CI) to compare bacterial frequencies. Results: A total of 393 samples were taken, of which 41.2% were from hands. Before disinfection, surfaces were more contaminated than hands with respectively 40.4% and 29.6% (PR = 1.3;CI 95% = [0.9 - 1.9]). After surface disinfection with 0.5% of chlorine solution, bacterial elimination was total, but partial on hands washed with soap, with residual contamination of 3.7%. A total of 108 strains were isolated before disinfection of which Klebsiella spp. 38.9% and Staphylococcus spp. 25.0%;after disinfection 4 strains were isolated of which: Staphylococcus spp. 75.0% and Klebsiella spp. 25.0%. Conclusion: Surface disinfection was more effective than hand washing with soap and water. We recommend proper hand washing.

Tissue-Engineered Products for Skin Regenerative Medicine

In a general wound healing process, foreign bodies and tissue detritus have to be broken down and then a new tissue is produced. However, the new tissue formation sometimes fails to proceed under the impaired conditions such as burn injury and intractable skin ulcer. A major obstruction to wound healing is infection. Another obstruction to wound healing is deficiency of growth factors. The endogenous levels of growth factors are reduced in some chronic wounds. To improve these wound conditions, researchers have been trying to create several types of artificial skins. The tissue-engineered products include three prime constituents, i.e., cells, growth factors, and materials. In this review, the practical design of tissue-engineered products for skin regenerative medicine is introduced. The first design makes it possible to release silver sulfadiazine (AgSD) from a wound dressing. The second design makes it possible to release Epidermal Growth Factor (EGF) from a wound dressing or a skin care product composed of hyaluronic acid spongy sheet containing bioactive ingredients. The third design makes it possible to release several types of growth factors from allogeneic fibroblasts within cultured dermal substitute. This tissue-engineered product is prepared by seeding allogeneic fibroblasts into a collagen and hyaluronic acid spongy sheet. Although allogeneic cells are rejected gradually in immune system, they are able to release some types of growth factors, thereby regenerating a damaged tissue. The clinical study demonstrates that these tissue-engineered products are promising for the treatment of burn injury and intractable skin ulcer.

Incidence of Urinary Tract Infections (UTI) amongst Patients Attending Primary Health Centres in Anambra State

Urinary tract infections (UTIs) are one of the most prevalent extra-intestinal bacterial infections. It is a common disease encountered in medical practice affecting people of all ages, from neonate to geriatric age group. These infections are on the increase for outpatients attending Primary Health Centres in Anambra State, Nigeria, therefore the need for this study. The prevalence rate of urinary tract infection, age distribution and influence of sex were determined. Susceptibility pattern of the infectious organisms to antimicrobial agent were examined. Clean-catch midstream urine samples were collected and examined. Out of 3000 urine samples examined, 528 bacterial isolates were recovered and characterized. These include: Escherichia coli (24.2%), Klebsiella spp. (18.2%), Staphylococcus aureus (18.2%), Proteus mirabilis (9.1%), Pseudomonas aeruginosa (9.1%), Enterococcus faecalis (9.1%), Citrobacter intermedius (6.1%) and Staphylococcus saprophyticus (6.1%). More females (52%) were infected than males (48%) and in both sexes, the highest incidence was found amongst the age group, 26 - 38 years. Gram negative rods had the highest incidence in both sexes. Among the towns in Anambra state, Umunya in southern province was observed to have the highest incidence rate of UTI. Susceptibility test of the bacterial isolates to antimicrobial agents showed that Staphylococcus aureus was sensitive to Cephalexin, Penicillin V, Erythromycin and Gentamycin while Pseudomonas aeruginosa was resistant to all the antibiotics. Escherichia coli and Klebsiella spp. were resistant to all the antibiotics except Gentamycin while Citrobacter intermedius was resistant only to Cephalexin and Erythromycin. This study provides the evidence of urinary tract infections amongst outpatients of primary health centres and the drugs for their control.

Analysis of Drug Resistance Spectra and Conjugative Plasmid Carrying Rates of P.aeruginosa and Acinetobacter

Antimicrobial susceptibility test was performed on 57 clinical isolates of P. aeruginosa and 36 clinical isolates of Acinetobacter with 11 antimicrobial agents including getamicin, amikacin, ciprofloxacin, ofloxacin, fleroxacin, piperacillin, cefotaxime, cefoperazone/sulbactam, ceftazidime, cefoperazone and doxycycline. Transferable drug resistance plasmid carrying rates of these clinical isolates were also studied. On the basis of the in vitro activities, 52.63%(30/57) of the isolated strains of P. aeruginosa were susceptible to antimicrobial agents selected (except doxycycline), 41.67%(15/36) of the isolated strains of Acinetobacter were susceptible to 11 antimicrobial agents. The sensitivity rate of P.aeruginosa and Acinetobacter to antimicrobial agents selected was 70% or greater to all except doxycycline. Furthermore, the sensitivity rate of P.aeruginosa to amikacin ciprofloxacin, ceftazidime, cefoperazone, cefoperazone/sulbactam, and that of Acinetobacter to cefoperazone/sulbactam, amikacin was more than 90%,among them amikacin, cefoperazone/sulbactam being the most effective. Plasmid analysis showed that 15.79%(9/57) P.aeruginosa strains and 13.89%(5/36) Acinetobacter strains carried plasmid. Conjugative plasmid carrying rates of P. aeruginosa strains and Acinetobacter strains were 7.02%(4/57), 13.89%(5/36), respectively. Conjugative plasmid didn′t play an important role in the formation and dissemination of drug resistance of P. aeruginosa and Acinetobacter.

Preventing Implant Bacterial Infections with Interconnected 3D Porous Structures (I3D)— A Proof-of-Concept Study

Oral antibiotics are often prescribed to prevent infection after implant surgery;however, only a small fraction of the antibiotics can reach the implants. Thus, there are concerns about overusing antibiotics. We designed and fabricated porous implants with interconnecting 3D structures (I3D) and hypothesized that such I3D structures could serve as a depository for antimicrobial agents to prevent infection locally. The implants were either treated with antibiotics or coated with silver nanoparticles (AgNPs) by electrodeposition to test this hypothesis. The antimicrobial assay was conducted, and bacterial growth zones of inhibition (ZOIs) were monitored. Overall, I3D implants resulted in larger ZOIs than did the solid implants, and the center I3D (cI3D)-implant produced the largest ZOI. In the antibiotic treatment testing, the diameters of ZOIs of the solid implant vs. I3D implant were about 14 mm vs. 15 to 18 mm on day 2;however, the diameter quickly reduced to 9 mm on day 3 and 5 mm on days 6 and 8 for the solid implant, while no obvious change of the zone was seen for I3D implants. For the AgNPs coated implants, the ZOIs for the I3D implants were generally greater than the solid implant over four weeks of incubation. A significantly larger ZOI (~1 - 2 mm larger on average) was seen for AgNPs coated I3D implants at 0.1 V - 0.01 M, 0.3 V - 0.01 M, and 1.5 V - 0.01 M treatments compared to AgNPs coated solid implants. Given that we have previously shown that I3D implants can reserve chemoattractants to recruit stem cells to enhance osseointegration, we conclude that implants with the I3D structures could be beneficial not only for osseointegration but also in preventing infection.

Effective antimicrobial therapies of urinary tract infections among children in low-and middle-income countries:A systematic review

Importance:Urinary tract infection(UTI)is one of the most common infections encountered in infancy and childhood.Despite the emerging problem of antibiotic resistance in recent years,the use of antibiotics for better management of UTIs is inevitable.Objective:This study aims to explore the efficacy and adverse effects of the available antimicrobial agents that are used in pediatric UTIs in low-and middle-income countries(LMICs).Methods:Five electronic databases were searched to identify relevant articles.Two reviewers independently performed screening,data extraction,and quality assessment of the available literature.Randomized controlled trials providing antimicrobial interventions in both male and female participants within the age range of 3 months to 17 years in LMICs were included.Results:Six randomized controlled trials from 13 LMICs were included in this review(four trials explored the efficacy).Due to high heterogeneity across the studies,a meta-analysis was not performed.Other than attrition and reporting bias,the risk of bias was moderate to high due to poor study designs.The differences in the efficacy and adverse events of different antimicrobials were not found to be statistically significant.Interpretation:This review indicates the necessity for additional clinical trials on children from LMICs with more significant sample numbers,adequate intervention periods,and study design.

A proposed model for understanding human-bacterial interactions:Space-time approach on community Escherichia coli occurrence and resistance phenomenon

Due to ecological effect, it is expected that population exposures to antimicrobial drugs may lead to microorganisms’ modifications, occasionally leading to resistance emergence. The present review was based on previous empirical data and on related literature search for quantitative empirical models exploring the human-bacterial interactions. Our previous studies have shown the emergence of ciprofloxacin resistant (CIP-R) Escherichia coli significantly related to previous specific levels of ciprofloxacin consumption and to urban clusters of CIP-R E. coli. The evidence of significant spatial clustering of antimicrobial resistance (ciprofloxacin resistance E. coli) reinforces the ecological effect hypothesis as a major drive in resistance emergence. In other words, human populations submitted to a certain ciprofloxacin or quinolone usage level may affect neighbours within certain geographical areas, not necessarily due to individual antimicrobial intake, but as a driving pressure over a modified circulating E. coli population. Apparently quantitative spatial-temporal analytical frameworks may be better for understanding human-bacterial interactions based on any of their epiphenomena (antimicrobial consumption, antimicrobial resistance, geno/phenotypic characteristics).

RESEARCH OF ANTIMICROBIAL AND RESISTANCE MODIFYING AGENTS FROM BENINESE PLANTS USED IN TRADITIONAL MEDICINE

In a world of increasing resistance to current antibiotics,search of novel therapeutic options is urgently needed.The aim of this work was to screen plant crude extracts for direct or indirect(inhibition of resistance)antimicrobial activity.Four crude extracts from 12 plants traditionally used in Benin for the treatment of infections were

Phenazines:Natural products for microbial growth control

The unprecedented problem of antibiotic resistance has become a major challenge for public health,which has contributed to an increase in infections caused by such bacteria.These microbial infections,typically biofilm-related,are alsocoupled to an increase in human mortality and morbidity.However,the demand for new antimicrobial agents hasincreased along with the evolution of microbial resistance mechanisms.Natural products produced by bacteria,such as phenazines,have been recognized as an important source for the development of new antimicrobial agents,through the exploitation of their capacity to increase oxidative stress in other organisms.Phenazines are a large groupof nitrogen-containing heterocyclic compounds and are essential for several cellular processes including iron acquisition,signaling events,enzymatic processes,and biofilm formation.Phenazine-inspired antibiotics(i.e.,2-bromo-1-hydroxyphenazine,2,4-dibromo-1-hydroxyphenazine,bromophenazine-21,phenazine-13,and phenazine-14)are veryactive against a wide range of gram-positive and gram-negative bacteria,including those associated with severe infections.In this study,mechanisms of phenazine-inspired antibiotics in the cellular processes of planktonic and sessilebacteria are reviewed.Moreover,the application of phenazine-inspired antibiotics for the eradication of multidrugresistant planktonic and biofilm bacterial infections is also reviewed.

Observing antimicrobial process with traceable gold nanodusters

Understanding the interaction of nanomaterials with biological systems has always been of high concern and interest.An emerging type of nanomaterials,ultrasmall metal nanoclusters(NCs,<2 nm in size),are promising in this aspect due to their well-defined molecular formulae and structures,as well as unique physical and chemical properties that are distinctly different from their larger counterparts(metal nanoparticles).For example,metal NCs possess intrinsic strong luminescence,which can be used for real-time tracking of their interactions with biological systems.Herein,luminescent gold(Au)NCs were used as traceable antimicrobial agents to study their interactions with the bacteria and tofurther understand their underlining antimicrobial mechanism.It is shown for the first time that the Au NCs would first attach on the bacterial membrane,penetrate,and subsequently accumulate inside the bacteria.Thereafter,the internalized Au NCs would induce reactive oxygen species(ROS)generation and damage the bacterial membrane,resulting in the leakage of bacterial contents,which can finally kill the bacteria.Traceable Au NCs(or other metal NCs)provide a promising platform to study the antimicrobial mechanisms as well as other fundamentals on the interfacing of functional nanomaterials with the biological systems,further increasing their acceptance in various biomedical applications.

Evaluation of in vitro antioxidant, antiglycation and antimicrobial potential of indigenous Myanmar medicinal plants

Objective： Myanmar has a long history of using medicinal plants for treatment of various diseases. To the best of our knowledge there are no previous reports on antiglycation activities of medicinal plants from Myanmar. Therefore, this study was aimed to evaluate the antioxidant, antiglycation and antimicrobial properties of 20 ethanolic extracts from 17 medicinal plants indigenous to Myanmar. Methods： In vitro scavenging assays of 2,2-diphenyl-l-picrylhydrazyl （DPPH）, nitric oxide （NO）, superoxide （SO） radicals were used to determine the antioxidant activities. Folin-Ciocalteu＇s method was performed to determine the total phenolic content. Antiglycation and antimicrobial activities were detected by bovine serum albumin-fluorescent assay and agar well diffusion method. Results： Terminalia cbebula Retz. （Fruit）, containing the highest total phenolic content, showed high antioxidant activities with inhibition of 77.98% ± 0.92% 88.95% ± 2.42%, 88.56% ±1.87% and 70.74% ±2.57% for DPPH, NO, SO assays and antiglycation activity respectively. It also showed the antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Escherichia coil, Pseudomonas aeruginosa and Candida albicans with inhibition zone of 19, 18, 17, 25 and 15 ram, respectively. Garcinia mangostana Linn. showed the strongest activities for SO and antiglycation assays with inhibition of 93.68% ± 2.63% and 82.37%± 1.78%. Bark of Melia sp. was the best NO radical scavenger with inhibition rate of 89.39%± 0.60%. Conclusion： The results suggest that these plants are potential sources of antioxidants with free radical-scavenging and antiglycation activities and could be useful for decreasing the oxidative stress and glycation end-product formation in glycation-related diseases.

An efficient one-pot three-component synthesis and antimicrobial evaluation of tetra substituted thiophene derivatives

A convenient one-pot three-component method for the preparation of tetra-substituted thiophene derivatives has been developed. Reaction ofacetyl acetone 1, phenyl isothiocynate 2 and 2-chloromethyI derivatives 3a-3c in the presence of potassium carbonate afforded the target compounds, namely ethyl 2-（4-acetyl-3-methyl-5-（phenylamino）thiophen-2-yl）-2-oxoacetate derivatives 4a-4e, ethyl 3-（4- acetyl-3-methyl-5-（phenylamino）thiophen-2-yl）-3-oxopropanoate derivatives 4f-4i, di（（4-acetyl-3- methyl-5-phenylamino）thiophen-2-yl）ketone derivatives 4j-4n in reasonable overall yields. The synthesized compounds were screened for antirnicrobial activity. The detailed synthesis, spectroscopic data and antimicrobial activities of synthesized compounds were reported.

Overcoming bacterial physical defenses with molecule-like ultrasmall antimicrobial gold nanoclusters

The size of metal nanoparticles(NPs)is crucial in their biomedical applications.Although abundant studies on the size effects of metal NPs in the range of 2-100 nm have been conducted,the exploration of the ultrasmall metal nanoclusters(NCs)of~1 nm in size with unique features is quite limited.We synthesize three different sized gold(Au)NCs of different Au atom numbers and two bigger sized Au NPs protected by the same ligand to study the size influence on antimicrobial efficacy.The ultrasmall Au NCs can easily traverse the cell wall pores to be internalized inside bacteria,inducing reactive oxygen species generation to oxidize bacterial membrane and disturb bacterial metabolism.This explains why the Au NCs are antimicrobial while the Au NPs are non-antimicrobial,suggesting the key role of size in antimicrobial ability.Moreover,in contrast to the widely known size-dependent antimicrobial properties,the Au NCs of different atom numbers demonstrate molecule-like instead of size-dependent antimicrobial behavior with comparable effectiveness,indicating the unique molecule-like feature of ultrasmall Au NCs.Overcoming the bacterial defenses at the wall with ultrasmall Au NCs changes what was previously believed to harmless to the bacteria instead to a highly potent agent against the bacteria.