-
1.
Scavenging Bacterial Siderophores with Engineered Lipocalin Proteins as an Alternative Antimicrobial Strategy.
Dauner, M, Skerra, A
Chembiochem : a European journal of chemical biology. 2020;(5):601-606
-
-
Free full text
-
Abstract
Iron acquisition mediated by siderophores, high-affinity chelators for which bacteria have evolved specific synthesis and uptake mechanisms, plays a crucial role in microbiology and in host-pathogen interactions. In the ongoing fight against bacterial infections, this area has attracted biomedical interest. Beyond several approaches to interfere with siderophore-mediated iron uptake from medicinal and immunochemistry, the development of high-affinity protein scavengers that tightly complex the siderophores produced by pathogenic bacteria has appeared as a novel strategy. Such binding proteins have been engineered based on siderocalin-also known as lipocalin 2-an endogenous human scavenger of enterobactin and bacillibactin that controls the systemic spreading of commensal bacteria such as Escherichia coli. By using combinatorial protein design, siderocalin was reshaped to bind several siderophores from Pseudomonas aeruginosa and, in particular, petrobactin from Bacillus anthracis, none of which is recognized by the natural protein. Such engineered versions of siderocalin effectively suppress the growth of corresponding pathogenic bacteria by depriving them of their iron supply and offer the potential to complement antibiotic therapy in situations of acute or persistent infection.
-
2.
Progress and prospects in the management of bacterial infections and developments in Phytotherapeutic modalities.
Akram, M, Riaz, M, Munir, N, Rasul, A, Daniyal, M, Ali Shah, SM, Shariati, MA, Shaheen, G, Akhtar, N, Parveen, F, et al
Clinical and experimental pharmacology & physiology. 2020;(7):1107-1119
Abstract
The advent of antibiotics revolutionized medical care resulting in significantly reduced mortality and morbidity caused by infectious diseases. However, excessive use of antibiotics has led to the development of antibiotic resistance and indeed, the incidence of multidrug-resistant pathogens is considered as a major disadvantage in medication strategy, which has led the scholar's attention towards innovative antibiotic sources in recent years. Medicinal plants contain a variety of secondary metabolites with a wide range of therapeutic potential against the resistant microbes. Therefore, the aim of this review is to explore the antibacterial potential of traditional herbal medicine against bacterial infections. More than 200 published research articles reporting the therapeutic potential of medicinal plants against drug-resistant microbial infections were searched using different databases such as Google Scholar, Science Direct, PubMed and the Directory of Open Access Journals (DOAJ), etc., with various keywords like medicinal plants having antibacterial activities, antimicrobial potentials, phytotherapy of bacterial infection, etc. Articles were selected related to the efficacious herbs easily available to local populations addressing common pathogens. Various plants such as Artocarpus communis, Rheum emodi, Gentiana lutea L., Cassia fistula L., Rosemarinus officinalis, Argemone maxicana L, Hydrastis canadensis, Citrus aurantifolia, Cymbopogon citrates, Carica papaya, Euphorbia hirta, etc, were found to have significant antibacterial activities. Although herbal preparations have promising potential in the treatment of multidrug-resistant bacterial infection, still more research is required to isolate phytoconstituents, their mechanism of action as well as to find their impacts on the human body.
-
3.
Comparison of the effects of Pueraria mirifica gel and of placebo gel on the vaginal microenvironment of postmenopausal women with Genitourinary Syndrome of Menopause (GSM).
Sritonchai, C, Manonai, J, Sophonsritsuk, A, Cherdshewasart, W
Maturitas. 2020;:49-54
Abstract
OBJECTIVE To compare the effects of a 12-week course of 5%Pueraria mirifica gel and placebo gel on the prevalence of bacterial vaginosis, vaginal fungi, vaginal pH, vaginal health index (VHI), and genitourinary symptoms in postmenopausal women. STUDY DESIGN In a randomized, double-blinded, placebo-controlled study (TCTR20160517002), 60 postmenopausal women were randomly assigned to a 12-week course of eitherP. mirifica gel or identical placebo gel. MAIN OUTCOME MEASURE Vaginal Nugent score, fungal culture, pH, VHI, and genitourinary symptoms were evaluated at baseline and after 12 weeks of treatment. RESULTS After 12 weeks of treatment, the proportion of participants with an abnormal Nugent score in the P. mirifica and the placebo groups were 6.7 % (2/30) and 23.3 % (7/30), respectively (p = 0.006). The mean changes in Nugent scores and VHI were significantly higher in the P. mirifica group (p < 0.05). There were no significant decreases in the prevalence of symptoms between the two groups after treatment (p > 0.05). CONCLUSION A 12-week course of treatment with 5 % P. mirifica vaginal gel in postmenopausal women with GSM has been proved to be effective in reducing indicators of bacterial vaginosis compared with placebo gel. Nevertheless, the effect on alleviating genital symptoms was not demonstrated.
-
4.
Interventions to reduce contaminated aerosols produced during dental procedures for preventing infectious diseases.
Kumbargere Nagraj, S, Eachempati, P, Paisi, M, Nasser, M, Sivaramakrishnan, G, Verbeek, JH
The Cochrane database of systematic reviews. 2020;(10):CD013686
-
-
Free full text
-
Abstract
BACKGROUND Many dental procedures produce aerosols (droplets, droplet nuclei and splatter) that harbour various pathogenic micro-organisms and may pose a risk for the spread of infections between dentist and patient. The COVID-19 pandemic has led to greater concern about this risk. OBJECTIVES To assess the effectiveness of methods used during dental treatment procedures to minimize aerosol production and reduce or neutralize contamination in aerosols. SEARCH METHODS Cochrane Oral Health's Information Specialist searched the following databases on 17 September 2020: Cochrane Oral Health's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (in the Cochrane Library, 2020, Issue 8), MEDLINE Ovid (from 1946); Embase Ovid (from 1980); the WHO COVID-19 Global literature on coronavirus disease; the US National Institutes of Health Trials Registry (ClinicalTrials.gov); and the Cochrane COVID-19 Study Register. We placed no restrictions on the language or date of publication. SELECTION CRITERIA We included randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on aerosol-generating procedures (AGPs) performed by dental healthcare providers that evaluated methods to reduce contaminated aerosols in dental clinics (excluding preprocedural mouthrinses). The primary outcomes were incidence of infection in dental staff or patients, and reduction in volume and level of contaminated aerosols in the operative environment. The secondary outcomes were cost, accessibility and feasibility. DATA COLLECTION AND ANALYSIS Two review authors screened search results, extracted data from the included studies, assessed the risk of bias in the studies, and judged the certainty of the available evidence. We used mean differences (MDs) and 95% confidence intervals (CIs) as the effect estimate for continuous outcomes, and random-effects meta-analysis to combine data. We assessed heterogeneity. MAIN RESULTS We included 16 studies with 425 participants aged 5 to 69 years. Eight studies had high risk of bias; eight had unclear risk of bias. No studies measured infection. All studies measured bacterial contamination using the surrogate outcome of colony-forming units (CFU). Two studies measured contamination per volume of air sampled at different distances from the patient's mouth, and 14 studies sampled particles on agar plates at specific distances from the patient's mouth. The results presented below should be interpreted with caution as the evidence is very low certainty due to heterogeneity, risk of bias, small sample sizes and wide confidence intervals. Moreover, we do not know the 'minimal clinically important difference' in CFU. High-volume evacuator Use of a high-volume evacuator (HVE) may reduce bacterial contamination in aerosols less than one foot (~ 30 cm) from a patient's mouth (MD -47.41, 95% CI -92.76 to -2.06; 3 RCTs, 122 participants (two studies had split-mouth design); very high heterogeneity I² = 95%), but not at longer distances (MD -1.00, -2.56 to 0.56; 1 RCT, 80 participants). One split-mouth RCT (six participants) found that HVE may not be more effective than conventional dental suction (saliva ejector or low-volume evacuator) at 40 cm (MD CFU -2.30, 95% CI -5.32 to 0.72) or 150 cm (MD -2.20, 95% CI -14.01 to 9.61). Dental isolation combination system One RCT (50 participants) found that there may be no difference in CFU between a combination system (Isolite) and a saliva ejector (low-volume evacuator) during AGPs (MD -0.31, 95% CI -0.82 to 0.20) or after AGPs (MD -0.35, -0.99 to 0.29). However, an 'n of 1' design study showed that the combination system may reduce CFU compared with rubber dam plus HVE (MD -125.20, 95% CI -174.02 to -76.38) or HVE (MD -109.30, 95% CI -153.01 to -65.59). Rubber dam One split-mouth RCT (10 participants) receiving dental treatment, found that there may be a reduction in CFU with rubber dam at one-metre (MD -16.20, 95% CI -19.36 to -13.04) and two-metre distance (MD -11.70, 95% CI -15.82 to -7.58). One RCT of 47 dental students found use of rubber dam may make no difference in CFU at the forehead (MD 0.98, 95% CI -0.73 to 2.70) and occipital region of the operator (MD 0.77, 95% CI -0.46 to 2.00). One split-mouth RCT (21 participants) found that rubber dam plus HVE may reduce CFU more than cotton roll plus HVE on the patient's chest (MD -251.00, 95% CI -267.95 to -234.05) and dental unit light (MD -12.70, 95% CI -12.85 to -12.55). Air cleaning systems One split-mouth CCT (two participants) used a local stand-alone air cleaning system (ACS), which may reduce aerosol contamination during cavity preparation (MD -66.70 CFU, 95% CI -120.15 to -13.25 per cubic metre) or ultrasonic scaling (MD -32.40, 95% CI - 51.55 to -13.25). Another CCT (50 participants) found that laminar flow in the dental clinic combined with a HEPA filter may reduce contamination approximately 76 cm from the floor (MD -483.56 CFU, 95% CI -550.02 to -417.10 per cubic feet per minute per patient) and 20 cm to 30 cm from the patient's mouth (MD -319.14 CFU, 95% CI - 385.60 to -252.68). Disinfectants ‒ antimicrobial coolants Two RCTs evaluated use of antimicrobial coolants during ultrasonic scaling. Compared with distilled water, coolant containing chlorhexidine (CHX), cinnamon extract coolant or povidone iodine may reduce CFU: CHX (MD -124.00, 95% CI -135.78 to -112.22; 20 participants), povidone iodine (MD -656.45, 95% CI -672.74 to -640.16; 40 participants), cinnamon (MD -644.55, 95% CI -668.70 to -620.40; 40 participants). CHX coolant may reduce CFU more than povidone iodine (MD -59.30, 95% CI -64.16 to -54.44; 20 participants), but not more than cinnamon extract (MD -11.90, 95% CI -35.88 to 12.08; 40 participants). AUTHORS' CONCLUSIONS We found no studies that evaluated disease transmission via aerosols in a dental setting; and no evidence about viral contamination in aerosols. All of the included studies measured bacterial contamination using colony-forming units. There appeared to be some benefit from the interventions evaluated but the available evidence is very low certainty so we are unable to draw reliable conclusions. We did not find any studies on methods such as ventilation, ionization, ozonisation, UV light and fogging. Studies are needed that measure contamination in aerosols, size distribution of aerosols and infection transmission risk for respiratory diseases such as COVID-19 in dental patients and staff.
-
5.
Recent Advances in Oral Nano-Antibiotics for Bacterial Infection Therapy.
Wu, ZL, Zhao, J, Xu, R
International journal of nanomedicine. 2020;:9587-9610
Abstract
Bacterial infections are the main infectious diseases and cause of death worldwide. Antibiotics are used to treat various infections ranging from minor to life-threatening ones. The dominant route to administer antibiotics is through oral delivery and subsequent gastrointestinal tract (GIT) absorption. However, the delivery efficiency is limited by many factors such as low drug solubility and/or permeability, gastrointestinal instability, and low antibacterial activity. Nanotechnology has emerged as a novel and efficient tool for targeting drug delivery, and a number of promising nanotherapeutic strategies have been widely explored to overcome these obstacles. In this review, we explore published studies to provide a comprehensive understanding of the recent progress in the area of orally deliverable nano-antibiotic formulations. The first part of this article discusses the functions and underlying mechanisms by which nanomedicines increase the oral absorption of antibiotics. The second part focuses on the classification of oral nano-antibiotics and summarizes the advantages, disadvantages and applications of nanoformulations including lipid, polymer, nanosuspension, carbon nanotubes and mesoporous silica nanoparticles in oral delivery of antibiotics. Lastly, the challenges and future perspective of oral nano-antibiotics for infection disease therapy are discussed. Overall, nanomedicines designed for oral drug delivery system have demonstrated the potential for the improvement and optimization of currently available antibiotic therapies.
-
6.
[Efficiency of immunomodulatotors for complex therapy of chronic recurrent cystitis in women].
Kuzmenko, AV, Kuzmenko, VV, Gyaurgiev, TA
Urologiia (Moscow, Russia : 1999). 2019;(2):9-14
Abstract
INTRODUCTION Currently, chronic recurrent cystitis is one of the most important problems in urology. Considering the role of immune status disorders in the pathogenesis of inflammatory diseases, the use of immunocorrective drugs as part of the complex therapy is of particular relevance. AIM: to study the efficiency of therapy for chronic recurrent bacterial cystitis in combination with immunomodulators (Galavit). MATERIALS AND METHODS A total of 60 women with acute stage of chronic recurrent bacterial cystitis were examined. The patients were randomized into 2 groups of 30 patients. In the control group, standard antibiotic therapy was administered. In the treatment group, patients received Galavit in combination with standard therapy. All patients were followed-up on the 1st, 5th and 10th day. Voiding diaries, chronobiological status and pain severity using a 5-point scale were evaluated. In addition, complete blood count, urinalysis, urine culture and enzyme immunoassay for determination of serum level of interleukin (IL) 1, IL-6, tumor necrosis factor (TNF-) were analyzed. A number of recurrences after 3 months of therapy was assessed. RESULTS Complex therapy in combination with Galavit in women with acute stage of chronic bacterial cystitis allows to decrease in desynchronosis by 20%, reduce pain by 2.5 times, frequency of urination by 1.7 times, the number of urgent voids and night urination by 2.4 and 5 times, respectively, by the 5th day of therapy. In the group of patients receiving immunomodulators a significantly more pronounced decrease in the level of IL-1, IL-6, TNF- and CRP was noted. During 3 months of follow-up, there were 2 recurrences in the control group and no recurrences in treatment group (10%). CONCLUSION The use of Galavit in the treatment of women with chronic recurrent bacterial cystitis has pathogenetic basis. A clear advantage of the drug is more rapid relief of symptoms, normalization of laboratory parameters, recovery of chronorhythms and the achievement of clinical remission.
-
7.
A review on anti-adhesion therapies of bacterial diseases.
Asadi, A, Razavi, S, Talebi, M, Gholami, M
Infection. 2019;(1):13-23
Abstract
BACKGROUND Infections caused by bacteria are a foremost cause of morbidity and mortality in the world. The common strategy of treating bacterial infections is by local or systemic administration of antimicrobial agents. Currently, the increasing antibiotic resistance is a serious and global problem. Since the most important agent for infection is bacteria attaching to host cells, hence, new techniques and attractive approaches that interfere with the ability of the bacteria to adhere to tissues of the host or detach them from the tissues at the early stages of infection are good therapeutic strategies. METHODS All available national and international databanks were searched using the search keywords. Here, we review various approaches to anti-adhesion therapy, including use of receptor and adhesion analogs, dietary constituents, sublethal concentrations of antibiotics, and adhesion-based vaccines. RESULTS Altogether, the findings suggest that interference with bacterial adhesion serves as a new means to fight infectious diseases. CONCLUSION Anti-adhesion-based therapies can be effective in prevention and treatment of bacterial infections, but further work is needed to elucidate underlying mechanisms.
-
8.
Efficacy of Probiotics and Prebiotics in Prevention of Infectious Complications Following Hepatic Resections: Systematic Review and Meta-Analysis.
Gan, Y, Su, S, Li, B, Fang, C
Journal of gastrointestinal and liver diseases : JGLD. 2019;:205-211
Abstract
BACKGROUND AND AIMS Infections occurring after hepatic resection cause significant morbidity, mortality, and prolonged hospitalization. Probiotics and prebiotics are considered to offer protection against post-operative infections. We aimed to determine the effect of probiotics and prebiotics on the post-operative infection rate after hepatic resection by conducting a systematic review and a meta-analysis. METHOD We searched various databases, namely, the PubMed, Medline, Embase, and Cochrane Controlled Trials Registry (CENTRAL), for randomized controlled trials evaluating the effect of probiotics and/or prebiotics on the infection rate following hepatic resection. Extracted data were pooled and subsequently used in a meta-analysis with a random-effects model. Review was reported following the PRISMA guidelines. RESULTS A total of 4 studies comprising 205 patients were included for our meta-analysis. The infection rates in the probiotic group and placebo group were 11.7% and 30.3%, respectively (p<0.001). The pooled risk ratio (RR) was 0.41 (95% confidence interval [CI]: 0.128-0.730). Subgroup analysis indicated that the wound infection rate in the probiotic group (5.3%) was significantly lower than that in the placebo group (RR: 0.387, 95% CI: 0.155-0.970, p=0.043). Furthermore, probiotics/prebiotics decreased the duration of hospital stay (-0.57 days; 95% CI: -0.861 to -0.274; p<0.001) and antibiotic use (mean difference: -3.89 days, 95% CI: -4.17 to -3.60; p<0.001). There was no significant statistical heterogeneity. CONCLUSION Our findings show that administration of probiotics and/or prebiotics prior to operation day decreases the infection rate post-liver resection and could shorten the duration of hospitalization and antibiotics use.
-
9.
The Use of a Combination of Vaccinium Macracarpon, Lycium barbarum L. and Probiotics (Bifiprost®) for the Prevention of Chronic Bacterial Prostatitis: A Double-Blind Randomized Study.
Chiancone, F, Carrino, M, Meccariello, C, Pucci, L, Fedelini, M, Fedelini, P
Urologia internationalis. 2019;(4):423-426
Abstract
INTRODUCTION To evaluate the efficacy of Bifiprost® + Serenoa Repens 320 mg versus Serenoa Repens 320 mg alone for the prevention of chronic bacterial prostatitis (CBP) due to enterobacteriaceae. METHODS Between September 2016 and September 2018, 120 patients with CBP at the National Institutes of Health (NIH type II) with recurrent infections due to enterobacteriaceae (Escherichia Coli and Enterococcus faecalis) were enrolled and randomized into 2 groups each to receive Bifiprost® + Serenoa Repens 320 mg (Group A) or Serenoa Repens 320 mg alone (Group B) daily for 24 weeks (after receiving a proper antibiotic treatment with subsequent culture negativization). The primary endpoint was the reduction in the episodes of prostatitis. The secondary endpoint evaluated was the score of the NIH-Chronic Prostatitis Symptom Index (NIH-CPSI). Evaluation was performed at baseline and at 12, 24, and 36 weeks. RESULTS The patients of the Group A experienced a significantly larger reduction in the prostatitis episodes than the Group B at 24 and 36 weeks, but they did not experience a significantly larger reduction at 12 weeks. After 12 weeks of treatment, the mean NIH-CPSI score was reduced in both groups compared with baselines, but no significant differences were seen between the Group A and Group B. On the contrary, we observed a significant difference in the mean NIH-CPSI score between the 2 groups at 24 and 36 weeks. CONCLUSION The association of Bifiprost® and Serenoa Repens 320 mg improves the prevention of the episodes of CBP due to enterobacteriaceae and ameliorates prostatitis-related symptoms after 6 months of therapy. The long-term impact on the entero-urinary route was also seen 3 months after the end of the treatment.
-
10.
Antibiotic Killing of Diversely Generated Populations of Nonreplicating Bacteria.
McCall, IC, Shah, N, Govindan, A, Baquero, F, Levin, BR
Antimicrobial agents and chemotherapy. 2019;(7)
Abstract
Nonreplicating bacteria are known to be (or at least commonly thought to be) refractory to antibiotics to which they are genetically susceptible. Here, we explore the sensitivity to killing by bactericidal antibiotics of three classes of nonreplicating populations of planktonic bacteria: (i) stationary phase, when the concentration of resources and/or nutrients are too low to allow for population growth; (ii) persisters, minority subpopulations of susceptible bacteria surviving exposure to bactericidal antibiotics; and (iii) antibiotic-static cells, bacteria exposed to antibiotics that prevent their replication but kill them slowly if at all, the so-called bacteriostatic drugs. Using experimental populations of Staphylococcus aureus Newman and Escherichia coli K-12 (MG1655) and, respectively, nine and seven different bactericidal antibiotics, we estimated the rates at which these drugs kill these different types of nonreplicating bacteria. In contrast to the common belief that bacteria that are nonreplicating are refractory to antibiotic-mediated killing, all three types of nonreplicating populations of these Gram-positive and Gram-negative bacteria are consistently killed by aminoglycosides and the peptide antibiotics daptomycin and colistin, respectively. This result indicates that nonreplicating cells, irrespectively of why they do not replicate, have an almost identical response to bactericidal antibiotics. We discuss the implications of these results to our understanding of the mechanisms of action of antibiotics and the possibility of adding a short-course of aminoglycosides or peptide antibiotics to conventional therapy of bacterial infections.