Antibiotic resistance: a primer and call to action

Evaluation of the Knowledge, Attitudes and Practice of Veterinary Professionals and Senior Animal Health Students in Central Gondar Zone, Gondar, Ethiopia: Antimicrobial Use and Resistance Perspectives

BACKGROUND

Antimicrobial resistance (AMR) poses a worldwide challenge to the well-being of animals and humans. The emergence of AMR is largely attributed to the improper utilization and overuse of antimicrobials. In order to combat this issue and promote responsible antimicrobial use (AMU), it is imperative for veterinary professionals and graduating students to possess extensive knowledge, maintain positive attitudes, and adhere to good practices regarding AMU and AMR.

OBJECTIVE

To assess the knowledge, attitude and practices (KAPs) of veterinary professionals and senior animal health students' towards veterinary AMU and AMR.

METHODS

A cross-sectional study design was conducted on purposefully selected 200 participants (60 of them were veterinary professionals from the districts and towns, and the remaining 140 were senior animal health university students). A self-administered, structured questionnaire was used to collect the necessary data, and descriptive statistics were used to summarize the data.

RESULTS

The study revealed that, overall, study participants' KAP were not satisfactory. From veterinary professionals, about 56.7% of respondents scored average knowledge, whereas 66.7% and 61.66% of them had negative attitudes and poor practices, respectively, on AMU and AMR. The study found that 56% of the participants' think the previous knowledge they acquired regarding AMU and AMR was not sufficient, and the internet was used as a source of drug information by the majority of participants. The majority (72%) of them were not taking special training on AMU and AMR. Regarding senior animal health students, this study indicated that 52% and 69.2% of the respondents had poor knowledge and a negative attitude, respectively, towards AMU and AMR.

CONCLUSION

Overall, veterinary professionals in the central Gondar zone have average knowledge, a negative attitude and poor practices. Poor knowledge and a negative attitude were also observed among senior animal health students towards AMU and AMR. Therefore, to fill the observed gaps, activities that enhance the skills of veterinary professionals and students should be implemented. Ingreted measures with animicrobial stewardship program and Nationwide studies are highly suggested to evaluate the overall status of veterinary professionals towards AMU and AMR.

Impact of Veterinary Feed Directive Rules Changes on the Prevalence of Antibiotic Resistance Bacteria Isolated from Cecal Samples of Food-Producing Animals at US Slaughterhouses

This study examined the impact of the 2017 Veterinary Feed Directive (VFD) rule changes on the prevalence of tetracycline-resistant and erythromycin-resistant bacteria (Salmonella spp., Campylobacter spp., and Escherichia coli) in cecal samples of food animals (cattle, swine, chicken, and turkey) at US slaughterhouses. Multivariable logistic regression was used to analyze 2013-2019 cecal samples of food-producing animals surveillance data from the National Antimicrobial Resistance Monitoring System (NARMS) in the U.S. The variables included year (used to evaluate VFD rule changes), host, and quarter of year. The analysis of surveillance data showed that the VFD rule changes have varying effects on tetracycline-resistant and erythromycin-resistant bacteria in food animals. For example, the odds of detecting tetracycline-resistant Salmonella spp. decreased in cattle but increased in chickens following the implementation of the VFD rule changes. Similarly, the odds of detecting tetracycline-resistant Escherichia coli decreased in chickens but increased in swine after the VFD rule changes. The odds of detecting erythromycin-resistant Campylobacter spp. increased in cattle but decreased in chickens after the VFD rule changes. In conclusion, the implementation of VFD rule changes has been beneficial in reducing the odds of detecting tetracycline-resistant Escherichia coli and erythromycin-resistant Campylobacter spp. in chickens, as well as tetracycline-resistant Salmonella spp. in cattle at US slaughterhouses.

Triton X-100 counteracts antibiotic resistance of Enterococcus faecalis: An in vitro study

OBJECTIVES

The high prevalence of antibiotic-resistant bacteria poses a threat to the global public health. The appropriate use of adjuvants to restore the antimicrobial activity of antibiotics against resistant bacteria could be an effective strategy for combating antibiotic resistance. In this study, we investigated the counteraction of Triton X-100 (TX-100) and the mechanisms underlying the antibiotic resistance of Enterococcus faecalis (E. faecalis).

METHODS

Standard, wild-type (WT), and induced antibiotic-resistant E. faecalis strains were used in this study. In vitro antibacterial experiments were conducted to evaluate the antimicrobial activities of gentamicin sulfate and ciprofloxacin hydrochloride in the presence and absence of 0.02 % TX-100 against both planktonic and biofilm bacteria. Transcriptomic and untargeted metabolomic analyses were performed to explore the molecular mechanisms of TX-100 as an antibiotic adjuvant. Additionally, membrane permeability, membrane potential, glycolysis-related enzyme activity, intracellular adenosine triphosphate (ATP), and expression levels of virulence genes were assessed. The biocompatibility of different drug combinations was also evaluated.

RESULTS

A substantially low TX-100 concentration improved the antimicrobial effects of gentamicin sulfate or ciprofloxacin hydrochloride against antibiotic-resistant E. faecalis. Mechanistic studies demonstrated that TX-100 increased cell membrane permeability and dissipated membrane potential. Moreover, antibiotic resistance and pathogenicity of E. faecalis were attenuated by TX-100 via downregulation of the ABC transporter, phosphotransferase system (PTS), and ATP supply.

CONCLUSIONS

TX-100 enhanced the antimicrobial activity of gentamicin sulfate and ciprofloxacin hydrochloride at a low concentration by improving antibiotic susceptibility and attenuating antibiotic resistance and pathogenicity of E. faecalis.

CLINICAL SIGNIFICANCE

These findings provide a theoretical basis for developing new root canal disinfectants that can reduce antibiotic resistance.

DIVE: a reference-free statistical approach to diversity-generating and mobile genetic element discovery

Diversity-generating and mobile genetic elements are key to microbial and viral evolution and can result in evolutionary leaps. State-of-the-art algorithms to detect these elements have limitations. Here, we introduce DIVE, a new reference-free approach to overcome these limitations using information contained in sequencing reads alone. We show that DIVE has improved detection power compared to existing reference-based methods using simulations and real data. We use DIVE to rediscover and characterize the activity of known and novel elements and generate new biological hypotheses about the mobilome. Building on DIVE, we develop a reference-free framework capable of de novo discovery of mobile genetic elements.

Predicting Extended-Spectrum Beta-Lactamase and Carbapenem Resistance in Enterobacteriaceae Bacteremia: A Diagnostic Model Systematic Review and Meta-Analysis

Enterobacteriaceae bacteremia, particularly when associated with antimicrobial resistance, can result in increased mortality, emphasizing the need for timely effective therapy. Clinical risk prediction models are promising tools, stratifying patients based on their risk of resistance due to ESBL and carbapenemase-producing Enterobacteriaceae in bloodstream infections (BSIs) and, thereby, improving therapeutic decisions. This systematic review and meta-analysis synthesized the literature on the performance of these models. Searches of PubMed and EMBASE led to the identification of 10 relevant studies with 6106 unique patient encounters. Nine studies concerned ESBL prediction, and one focused on the prediction of carbapenemases. For the two ESBL model derivation studies, the discrimination performance showed sensitivities of 53-85% and specificities of 93-95%. Among the four ESBL model derivation and validation studies, the sensitivities were 43-88%, and the specificities were 77-99%. The sensitivity and specificity for the subsequent external validation studies were 7-37% and 88-96%, respectively. For the three external validation studies, only two models were evaluated across multiple studies, with a pooled AUROC of 65-71%, with one study omitting the sensitivity/specificity. Only two studies measured clinical utility through hypothetical therapy assessments. Given the limited evidence on their interventional application, it would be beneficial to further assess these or future models, to better understand their clinical utility and ensure their safe and impactful implementation.

Effect of veterinary feed directive rule changes on tetracycline-resistant and erythromycin-resistant bacteria (Salmonella, Escherichia, and Campylobacter) in retail meats in the United States

BACKGROUND

Antimicrobial-resistant bacteria are a growing public health threat. In 2017 the U.S. Food and Drug Administration implemented Veterinary Feed Directive (VFD) rules changes to limit medically important antimicrobial use in food-producing animals, combating antimicrobial-resistant bacteria. The effect of the VFD rule changes on the occurrence of bacteria resistant to medically-important antimicrobials in retail meats is yet to be investigated in the U.S. This study investigates whether the VFD rule changes affected the occurrence of tetracycline-resistant and erythromycin-resistant bacteria (Salmonella, Escherichia, and Campylobacter) in retail meats in the U.S.

METHODS

Multivariable mixed effect logistic regression models were used to analyze 2002-2019 retail meats surveillance data from the National Antimicrobial Resistance Monitoring System (NARMS) in the U.S. Variables included VFD rule changes, meat type, quarter of year, and raising claims. A potential association between these variables and the occurrence of tetracycline-resistant and erythromycin-resistant bacteria (Salmonella, Escherichia, and Campylobacter) in retail meats was estimated.

RESULTS

Analysis included data regarding tetracycline-resistant Salmonella (n = 8,501), Escherichia (n = 20, 283), Campylobacter (n = 9,682), and erythromycin-resistant Campylobacter (n = 10,446) in retail meats. The odds of detecting tetracycline-resistant Escherichia (OR = 0.60), Campylobacter (OR = 0.89), and erythromycin-resistant Campylobacter (OR = 0.43) in chicken breast significantly decreased after the VFD rule changes, compared to the pre-VFD rule change period. The odds of detecting tetracycline-resistant Salmonella (0.66), Escherichia (OR = 0.56), and Campylobacter (OR = 0.33) in ground turkey also significantly decreased. However, the odds of detecting tetracycline-resistant Salmonella (OR = 1.49) in chicken breast and erythromycin-resistant Campylobacter (OR = 4.63) in ground turkey significantly increased. There was no significant change in the odds of detecting tetracycline-resistant Salmonella and Escherichia in ground beef or pork chops.

CONCLUSIONS

The implementation of VFD rule changes had a beneficial effect by reducing the occurrence of tetracycline-resistant and erythromycin-resistant bacteria in chicken and ground turkey. Ongoing surveillance of antimicrobial resistance and antimicrobial use could complement the implementation of stewardship such as VFD rule in food-producing animals in the U.S.

Effects of thyme (Thymus vulgaris L.) essential oil supplementation on the microbiological quality of raw milk of lactating dairy cows

This study aimed to evaluate the supplementation of lactating cows with thyme (Thymus vulgaris L.) essential oil (TEO) on the centesimal composition and microbiological quality of raw milk. Twenty-four lactating cows (400 ± 42.9 kg initial body weight, 50 ± 10 days in milk, and 22.05 ± 4.34 kg/d milk production, second lactation) from an experimental farm in the region of Ribeirão Preto/SP, Brazil were used, divided randomly assigned to two groups: Control- 8 mL/d soybean oil (as placebo), and Treatment- 8 mL/d TEO, per cow/day. Both oils were offered encapsulated and administered daily via esophageal tube, for 21 days. On d 21, milk was collected from each animal, fractionated into 50 mL bottles. The microbiological quality of the raw was analyzed for standard plate count (SPC), milk composition (protein, fat, lactose, and solids non fat (SNF)), and thymol concentration. The treated group had significantly lower mean values for SPC after 168 h under refrigeration, and no differences were observed in the milk composition. The supplementation of lactating dairy cows with 8 mL/d TEO represents a promising alternative to controlling microbial spoilage in raw milk, allowing the reduction of economic losses in the milk chain, in addition to providing consumers with a safer product. However, further research should be conducted to better assess the effect of TEO supplementation on milk quality, such as sensory and toxicity studies, in addition to evaluating the effect of milk processing on oil activity and the effect on consumer health.

CRISPR-Cas9 System: A Prospective Pathway toward Combatting Antibiotic Resistance

Antibiotic resistance is rising to dangerously high levels throughout the world. To cope with this problem, scientists are working on CRISPR-based research so that antibiotic-resistant bacteria can be killed and attacked almost as quickly as antibiotic-sensitive bacteria. Nuclease activity is found in Cas9, which can be programmed with a specific target sequence. This mechanism will only attack pathogens in the microbiota while preserving commensal bacteria. This article portrays the delivery methods used in the CRISPR-Cas system, which are both viral and non-viral, along with its implications and challenges, such as microbial dysbiosis, off-target effects, and failure to counteract intracellular infections. CRISPR-based systems have a lot of applications, such as correcting mutations, developing diagnostics for infectious diseases, improving crops productions, improving breeding techniques, etc. In the future, CRISPR-based systems will revolutionize the world by curing diseases, improving agriculture, and repairing genetic disorders. Though all the drawbacks of the technology, CRISPR carries great potential; thus, the modification and consideration of some aspects could result in a mind-blowing technique to attain all the applications listed and present a game-changing potential.

Synthesis, Antimicrobial, and Antibiofilm Activities of Some Novel 7-Methoxyquinoline Derivatives Bearing Sulfonamide Moiety against Urinary Tract Infection-Causing Pathogenic Microbes

A new series of 4-((7-methoxyquinolin-4-yl) amino)-N-(substituted) benzenesulfonamide 3(a-s) was synthesized via the reaction of 4-chloro-7-methoxyquinoline 1 with various sulfa drugs. The structural elucidation was verified based on spectroscopic data analysis. All the target compounds were screened for their antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, and unicellular fungi. The results revealed that compound 3l has the highest effect on most tested bacterial and unicellular fungal strains. The highest effect of compound 3l was observed against E. coli and C. albicans with MIC = 7.812 and 31.125 µg/mL, respectively. Compounds 3c and 3d showed broad-spectrum antimicrobial activity, but the activity was lower than that of 3l. The antibiofilm activity of compound 3l was measured against different pathogenic microbes isolated from the urinary tract. Compound 3l could achieve biofilm extension at its adhesion strength. After adding 10.0 µg/mL of compound 3l, the highest percentage was 94.60% for E. coli, 91.74% for P. aeruginosa, and 98.03% for C. neoformans. Moreover, in the protein leakage assay, the quantity of cellular protein discharged from E. coli was 180.25 µg/mL after treatment with 1.0 mg/mL of compound 3l, which explains the creation of holes in the cell membrane of E. coli and proves compound 3l's antibacterial and antibiofilm properties. Additionally, in silico ADME prediction analyses of compounds 3c, 3d, and 3l revealed promising results, indicating the presence of drug-like properties.

Prediction of ciprofloxacin resistance in hospitalized patients using machine learning

BACKGROUND

Ciprofloxacin is a widely used antibiotic that has lost efficiency due to extensive resistance. We developed machine learning (ML) models that predict the probability of ciprofloxacin resistance in hospitalized patients.

METHODS

Data were collected from electronic records of hospitalized patients with positive bacterial cultures, during 2016-2019. Susceptibility results to ciprofloxacin (n = 10,053 cultures) were obtained for Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus. An ensemble model, combining several base models, was developed to predict ciprofloxacin resistant cultures, either with (gnostic) or without (agnostic) information on the infecting bacterial species.

RESULTS

The ensemble models' predictions are well-calibrated, and yield ROC-AUCs (area under the receiver operating characteristic curve) of 0.737 (95%CI 0.715-0.758) and 0.837 (95%CI 0.821-0.854) on independent test-sets for the agnostic and gnostic datasets, respectively. Shapley additive explanations analysis identifies that influential variables are related to resistance of previous infections, where patients arrived from (hospital, nursing home, etc.), and recent resistance frequencies in the hospital. A decision curve analysis reveals that implementing our models can be beneficial in a wide range of cost-benefits considerations of ciprofloxacin administration.

CONCLUSIONS

This study develops ML models to predict ciprofloxacin resistance in hospitalized patients. The models achieve high predictive ability, are well calibrated, have substantial net-benefit across a wide range of conditions, and rely on predictors consistent with the literature. This is a further step on the way to inclusion of ML decision support systems into clinical practice.

Knowledge, Attitudes and Practice Regarding Antibiotic Prescription by Medical Interns: A Qualitative Study in Spain

Antibiotic resistance is an issue of growing importance in the public health sphere. Medical interns are of great relevance when it comes to the source of this problem. This study therefore sought to ascertain which factors influence the management of antibiotic therapy by this population, in order to pinpoint the possible causes of misprescribing habits. We conducted a qualitative study based on focus group techniques, with groups consisting of medical interns from the Santiago de Compostela Clinical University Teaching Hospital. Our study identified factors which the participants considered to be determinants of antibiotic use and their relationship with the appearance of resistance. The single most repeated factor was the influence of the attending physician’s judgement; other factors included a high healthcare burden or prescribing inertia. This stage is an opportunity to correct misprescribing habits, by implementing educational interventions aimed at modifying the identified factors.

Antibiotic stewardship with upper respiratory tract infection patients at student health centers: Providers' communication experiences and strategies

BACKGROUND

Effective provider-patient communication can improve antibiotic stewardship in primary care, but providers find it challenging to discuss antibiotics with patients. This study, focused on college student health centers, examines patients' tactics for obtaining antibiotics for upper respiratory tract infections and providers' communication strategies for improving patient understanding and reducing demand.

METHODS

Health care providers (N = 103) employed at student health centers on large and primarily residential college campuses in the U.S. completed an online survey.

RESULTS

Providers perceived patients as wanting antibiotics in approximately 50% of upper respiratory tract infection visits and noted multiple patient tactics to obtain them, including reports of prior prescribing, suggested diagnoses, and direct requests. Providers used multiple strategies to manage patient demand, including explanation of the diagnosis, antibiotic utility and risks, and treatment plan.

DISCUSSION

This study extends prior research indicating that patients exercise a range of influence tactics to obtain antibiotics, and thereby create discomfort for providers. The study also elucidates providers' efforts to counter these influence tactics and steward antibiotics by educating patients.

CONCLUSIONS

Additional research is needed to specify the most effective ways for providers to respond to patients' influence tactics, including the best approaches to explaining diagnosis, treatment, and antibiotic resistance.

Emergent crisis of antibiotic resistance: A silent pandemic threat to 21st century

Antibiotic resistance has become an indispensably alarming menace to the global community. The primary factors are overuse and abuse of antibiotics, lack of novel medicines under development, the health care industry's focus on profit, and the absence of diagnostic testing prior to the prescription of antibiotics. Additionally, over the past few decades, the main factors contributing to the global spread of antibiotic resistance have been the overuse of antibiotics in livestock and other animals, drug efficacy, development of fewer new vaccines, environmental toxicity, transmission through travel, and lack of funding for healthcare research and development. These factors have accelerated resistance in microorganisms through structural and functional modifications in bacteria such as reduced drug permeability, increased efflux pumps, enzymatic antibiotic modification, and change in drug target, intracellular infection, and biofilm creation. There has been an increase in resistance during the pandemic and among cancer patients due to improper prescriptions. A number of modern therapeutic alternatives have been developed to curb widespread antibiotic resistance such as nanoparticle, bacteriophage, and antimicrobial biochemical approaches. It is high time to explore new alternatives to curtail enormous increase in resistant pathogens which could be an incurable global confrontation. This review highlights the complete insight on the global drivers of resistance along with the modes of action and impacts, finally discussing the latest therapeutic alternatives.

Antibiotic Prescription for Dental Procedures in Type 1 Diabetic Children

In diabetic patients, maintaining blood glucose levels as close to normal as possible is an objective in dental management especially in pediatric ones. Patients with poorly controlled diabetes are at greater risk of developing infections. Therefore, the prescription of antibiotics may be necessary for some dental procedures.

Aim

The aim is to optimize the benefit and minimize the risk of antibiotics in dental treatments performed in diabetic children.

Materials and methods

A cross-sectional approach was conducted on 155 type 1 diabetic children (72 controlled and 83 uncontrolled). The types of dental acts held for the study were pulpotomies, pulpectomies, pediatric crowns, scaling, and extraction. For the balanced diabetic patients, no antibiotics were prescribed except for infected teeth. In the unbalanced diabetic group, for the acts causing bleeding, prophylactic antibiotics were administered. In presence of dental infection, antibiotics were administered for at least 5 days.

Results

The analysis of data was carried out using Statistical Package for the Social Sciences Computer Software (SPSS 21.0, Inc., Chicago, Illinois, USA). A probability value of <0.05 was regarded as statistically significant. Around 126 acts in the balanced group and 145 in the unbalanced ones were performed. In balanced diabetic children, 125 successes and one failure were noted. In the unbalanced group, 142 successes and three failures were recorded. The comparison between variables did not show any statistical significance (p-value = 0.382).

Conclusion

This study demonstrated that working with diabetic young patients is possible and safe as long as some measures are considered. It is crucial to identify the dental acts that necessitate antibiotics administration and to differentiate between balanced and unbalanced diabetic children for the same dental procedure.

How to cite this article

Nassif N, Noueiri B. Antibiotic Prescription for Dental Procedures in Type 1 Diabetic Children. Int J Clin Pediatr Dent 2023;16(1):60-63.

Multidrug-Resistant Gram-Negative Bacteria Contaminating Raw Meat Sold in Accra, Ghana

BACKGROUND

Efforts to combat antimicrobial resistance (AMR) should be based on the One Health approach, involving human health, animal health, and the environment. In Ghana, previous studies on AMR have given little attention to animal source food, a major route of transmission of antibiotic-resistant zoonotic pathogens. The aim of this study was to investigate the occurrence of multidrug-resistant (MDR) bacteria in meat sold in Accra.

METHODS

This was a cross-sectional study in which 270 meat samples (90 each of beef, goat meat, and chicken) were collected, and investigated for contamination with multidrug-resistant bacteria. The bacteria were subjected to susceptibility testing against amikacin (30 µg), ampicillin (10 µg), amoxicillin-clavulanate (20/10 µg), cefuroxime (30 µg), ceftriaxone (30 µg), ceftazidime (30 µg), cefepime (30 µg), ciprofloxacin (5 µg), trimethoprim-sulfamethoxazole (1.25/23.75 µg), ertapenem (10 µg), meropenem (10 µg), imipenem (10 µg), tigecycline (15 µg), and gentamicin (10 µg).

RESULTS

Thirty-two different types of bacteria, totalling 558, were isolated, the predominant being Escherichia coli (44.6%), Aeromonas hydrophila (19.9%), Vibrio cholerae (3.4%), Aeromonas veronii (3.2%), and Klebsiella pneumoniae (3.1%). The prevalence of MDR among the contaminating bacteria was 14.9%. The MDR distribution among the predominant bacteria was Escherichia coli (18.7%), Aeromonas hydrophila (11.1%), Vibrio cholerae and Aeromonas veronii (0.0% each), and K. pneumoniae (5.6%). Moreover, 2.0% of the contaminating bacteria were extended-spectrum beta-lactamase (ESBL) producers, all of which occurred in the chicken samples, and their distribution was: Escherichia coli (1.3%), Klebsiella pneumoniae, Pantoea spp., Enterobacter cloacae, and Serratia plymuthica (0.2% each).

CONCLUSIONS

The meat samples were heavily contaminated with Escherichia coli and Aeromonas hydrophila, and less frequently, with Vibrio cholerae, Klebsiella pneumoniae, and other organisms. The prevalence of multidrug-resistant bacteria was moderate (14.9%), while that of ESBL producers was low (2%).

Metagenomic Characterization of Resistance Genes in Deception Island and Their Association with Mobile Genetic Elements

Antibiotic resistance genes (ARGs) are undergoing a remarkably rapid geographic expansion in various ecosystems, including pristine environments such as Antarctica. The study of ARGs and environmental resistance genes (ERGs) mechanisms could provide a better understanding of their origin, evolution, and dissemination in these pristine environments. Here, we describe the diversity of ARGs and ERGs and the importance of mobile genetic elements as a possible mechanism for the dissemination of resistance genes in Antarctica. We analyzed five soil metagenomes from Deception Island in Antarctica. Results showed that detected ARGs are associated with mechanisms such as antibiotic efflux, antibiotic inactivation, and target alteration. On the other hand, resistance to metals, surfactants, and aromatic hydrocarbons were the dominant ERGs. The taxonomy of ARGs showed that Pseudomonas, Psychrobacter, and Staphylococcus could be key taxa for studying antibiotic resistance and environmental resistance to stress in Deception Island. In addition, results showed that ARGs are mainly associated with phage-type mobile elements suggesting a potential role in their dissemination and prevalence. Finally, these results provide valuable information regarding the ARGs and ERGs in Deception Island including the potential contribution of mobile genetic elements to the spread of ARGs and ERGs in one of the least studied Antarctic ecosystems to date.

Fecal carriage of vanB antibiotic resistance gene affects adipose tissue function under vancomycin use

Detrimental consequences of antibiotic treatment may include long-lasting disruption of the gut microbiota. Previous studies found no negative effects of antibiotics on metabolic health, although individualized responses were observed. Here, we aimed to investigate the subject-specific response to vancomycin use in tissue-specific insulin sensitivity by stratifying individuals based on the presence of antibiotic resistance genes (ARGs) or opportunistic pathogens (OPs) in the baseline fecal microbiota. Quantitative Polymerase Chain Reaction (qPCR) was used to detect ARGs and OPs in DNA isolated from fecal samples of 56 males with overweight/obesity (Body Mass Index: 25-35 kg/m²) and impaired glucose metabolism (fasting plasma glucose ≥5.6 mmol/L and/or 2-hour glucose 7.8-11.1 mmol/L). A two-step hyperinsulinemic-euglycemic clamp was performed to determine tissue-specific insulin sensitivity. Abdominal subcutaneous adipose tissue (AT) gene expression was assessed using Affymetrix microarray. Gut microbial composition was determined using the Human Intestinal Tract Chip (HITChip) microarray. At baseline, the vancomycin resistance gene vanB was present in 60% of our population. In individuals that were vanB-negative at baseline, AT insulin sensitivity (insulin-mediated suppression of plasma free fatty acids) improved during vancomycin use, while it decreased among vanB-positive individuals (% change post versus baseline: 14.1 ± 5.6 vs. -6.7 ± 7.5% (p = .042)). The vancomycin-induced increase in AT insulin sensitivity was accompanied by downregulation of inflammatory pathways and enrichment of extracellular matrix remodeling pathways in AT. In the vanB-positive group, well-known vanB-carrying bacteria, Enterococcus and Streptococcus, expanded in the gut microbiome. In conclusion, microbiome composition and adipose tissue biology were differentially affected by vancomycin treatment based on fecal vanB carriage.

Photodynamic therapy and combinatory treatments for the control of biofilm-associated infections

The advent of antimicrobial resistance has added considerable impact to infectious diseases both in the number of infections and healthcare costs. Furthermore, the relentless emergence of multidrug-resistant bacteria, particularly in the biofilm state, has made mandatory the discovery of new alternative antimicrobial therapies that are capable to eradicate resistant bacteria and impair the development of new forms of resistance. Amongst the therapeutic strategies for treating biofilms, antimicrobial photodynamic therapy (aPDT) has shown great potential in inactivating several clinically relevant micro-organisms, including antibiotic-resistant 'priority bacteria' declared by the WHO as critical pathogens. Its antimicrobial effect is centred on the basis that harmless low-intensity light stimulates a non-toxic dye named photosensitizer, triggering the production of reactive oxygen species upon photostimulation. In addition, combination therapies of aPDT with other antimicrobial agents (e.g. antibiotics) have also drawn considerable attention, as it is a multi-target strategy. Therefore, the present review highlights the recent advances of aPDT against biofilms, also covering progress on combination therapy.

Novel benzothiazole‒urea hybrids: Design, synthesis and biological activity as potent anti-bacterial agents against MRSA

Novel benzothiazole‒urea hybrids were designed, synthesized and evaluated their anti-bacterial activity. They only exhibited anti-bacterial activity against Gram-positive bacteria, including clinical methicillin-resistant S. aureus (MRSA), compounds 5f, 5i, 8e, 8k and 8l exhibited potent activity (MIC = 0.39 and 0.39/0.78 μM against SA and MRSA, respectively). Crystal violet assay showed that compounds 5f, 8e and 8l not only inhibited the formation of biofilms but also eradicated preformed biofilms. Compound 8l had membrane disruption, little propensity to induce resistance, benign safety and in vivo anti-MRSA efficacy in a mouse model of abdominal infection. Therefore, our data demonstrated the potential to advance benzothiazole‒urea hybrids as a new class of antibiotics.

The highly diverse Antarctic Peninsula soil microbiota as a source of novel resistance genes

The rise of multiresistant bacterial pathogens is currently one of the most critical threats to global health, encouraging a better understanding of the evolution and spread of antimicrobial resistance. In this regard, the role of the environment as a source of resistance mechanisms remains poorly understood. Moreover, we still know a minimal part of the microbial diversity and resistome present in remote and extreme environments, hosting microbes that evolved to resist harsh conditions and thus a potentially rich source of novel resistance genes. This work demonstrated that the Antarctic Peninsula soils host a remarkable microbial diversity and a widespread presence of autochthonous antibiotic-resistant bacteria and resistance genes. We observed resistance to a wide array of antibiotics among isolates, including Pseudomonas resisting ten or more different compounds, with an overall increased resistance in bacteria from non-intervened areas. In addition, genome analysis of selected isolates showed several genes encoding efflux pumps, as well as a lack of known resistance genes for some of the resisted antibiotics, including colistin, suggesting novel uncharacterized mechanisms. By combining metagenomic approaches based on analyzing raw reads, assembled contigs, and metagenome-assembled genomes, we found hundreds of widely distributed genes potentially conferring resistance to different antibiotics (including an outstanding variety of inactivation enzymes), metals, and biocides, hosted mainly by Polaromonas, Pseudomonas, Streptomyces, Variovorax, and Burkholderia. Furthermore, a proportion of these genes were found inside predicted plasmids and other mobile elements, including a putative OXA-like carbapenemase from Polaromonas harboring conserved key residues and predicted structural features. All this evidence indicates that the Antarctic Peninsula soil microbiota has a broad natural resistome, part of which could be transferred horizontally to pathogenic bacteria, acting as a potential source of novel resistance genes.

Antibiofilm and anticancer activities of unripe and ripe Azadirachta indica (neem) seed extracts

BACKGROUND

Antibiotic resistances of pathogens and breast cancer warrant the search for new alternative strategies. Phytoextracts can eradicate microbe-borne diseases as well as cancer with lower side effects compared to conventional antibiotics.

AIM

Unripe and ripe Azadirachta indica (neem) seed extracts were explored as potential antibiofilm and anticancer agents in combating multidrug-resistant infectious bacteria as well as anticancer agents against the MDR breast cancer cell lines.

METHODS

Shed-dried neem seeds (both unripe and ripe) were pulverized and extracted using methanol. The chemical components were identified with FTIR and gas chromatography - mass spectrometry. Antibiofilm activity of neem seed extracts were assessed in terms of minimum biofilm inhibitory concentration (MBIC), minimum biofilm eradication concentration (MBEC), and fluorescence microscopic studies on Staphylococcus aureus and Vibrio cholerae. Bacterial cells were studied by fluorescence microscopy using acridine orange/ethidium bromide as the staining agents. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were evaluated to observe the antibacterial activities. Cytotoxicity of the extracts against human blood lymphocytes and the anticancer activity against drug-resistant breast cancer cell lines were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and fluorescence-activated cell sorting (FACS) studies.

RESULTS

4-Ethyl-2-hydroxy-2-cyclopentene-1-one, phthalic acid, and 2-hexyl-tetrahydro thiophane were the major compounds in unripe neem seed, whereas 3,5-dihydroxy-6-methyl-2,3-dihydro-4-H-pyran-4-one and 4-ethylbenzamide were predominant in ripe neem seed. Triazine derivatives were also common for both the extracts. MBIC values of unripe and ripe neem seed extracts for S. aureus are 75 and 100 µg/mL, respectively, and for V. cholerae, they are 100 and 300 µg/mL, respectively. MBEC values of unripe and ripe seed extracts are 500 and 300 µg/mL, respectively for S. aureus and for V. cholerae the values are 700 and 500 µg/mL, respectively. Fluorescence microscopic studies at 16 and 24 h, after bacterial culture, demonstrate enhanced antibiofilm activity for the ripe seed extract than that of the unripe seeds for both the bacteria. MTT assay reveals lower cytotoxicity of both the extracts towards normal blood lymphocytes, and anticancer activity against breast cancer cell line (MDA-MB-231) with superior activity of ripe seed extract. FACS studies further supported higher anticancer activity for ripe seed extract.

CONCLUSIONS

Methanolic extract of neem seeds could substantially inhibit and eradicate biofilm along with their potent antibacterial and anticancer activities. Both the extracts showed higher antibiofilm and antibacterial activity against S. aureus (gram-positive) than V. cholerae (gram-negative). Moreover, ripe seed extract showed higher antibiofilm and anticancer activity than unripe extracts.

Synergistic In Vitro Antimicrobial Activity of Triton X-100 and Metformin against Enterococcus faecalis in Normal and High-Glucose Conditions

The prevention and treatment of oral diseases is more difficult in diabetic patients with poorly controlled blood glucose levels. This study aims to explore an effective, low-cytotoxicity medication for root canal treatment in diabetic patients. The antibacterial effect of the combination of Triton X-100 (TX-100) and metformin (Met) on Enterococcus faecalis (E. faecalis) was evaluated by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration required to kill 99% bacteria (MBC₉₉) and by conducting dynamic time-killing assays. While the antibiofilm activity was measured by crystal violet (CV) assay, field emission scanning electron microscope (FE-SEM), confocal laser scanning microscope (CLSM) and colony-forming unit (CFU) counting assays. The expression of relative genes was evaluated by real-time quantitative polymerase chain reaction (RT-qPCR), and the cytotoxicity of the new combination on MC3T3-E1 cell was also tested. Results showed that the antibacterial and antibiofilm activities of Met could be significantly enhanced by very low concentrations of TX-100 in both normal and high-glucose conditions, with a much lower cytotoxicity than 2% chlorhexidine (CHX). Thus, the TX-100 + Met combination may be developed as a promising and effective root canal disinfectant for patients with diabetes.

Antibacterial, Antibiofilm and Anti-Virulence Activity of Biactive Fractions from Mucus Secretion of Giant African Snail Achatina fulica against Staphylococcus aureus Strains

Staphylococcus aureus is an important etiological agent that causes skin infections, and has the propensity to form biofilms, leading to significant mortality and morbidity in patients with wounds. Mucus secretion from the Giant African snail Achatina fulica is a potential source of biologically active substances that might be an important source for new drugs to treat resistant and biofilm-forming bacteria such as S. aureus. This study evaluated the effect of semi-purified fractions from the mucus secretion of A. fulica on the growth, biofilm formation and virulence factors of S. aureus. Two fractions: FMA30 (Mw >30 kDa) and FME30 (Mw 30−10 kDa) exhibited antimicrobial activity against S. aureus with a MIC₅₀ of 25 and 125 µg/mL, respectively. An inhibition of biofilm formation higher than 80% was observed at 9 µg/mL with FMA30 and 120 µg/mL with FME30. Furthermore, inhibition of hemolytic and protease activity was determined using a concentration of MIC₂₀, and FME30 showed a strong inhibitory effect in the formation of clots. We report for the first time the effect of semi-purified fractions of mucus secretion of A. fulica on biofilm formation and activity of virulence factors such as α-hemolysin, coagulase and proteases produced by S. aureus strains.

Antibiotics for Fever Among Children: Findings From the Surveillance for Enteric Fever in India Cohorts

Background

Acute febrile illness in children is frequently treated with antibiotics. However, the inappropriate use of antibiotics has led to the emergence of multidrug-resistant pathogens.

Methods

We measured use of antibiotics for fever in 4 pediatric cohorts that were part of the Surveillance for Enteric Fever in India (SEFI) network. In this network, 24 062 children were followed up weekly, capturing information on fever and other morbidity between October 2017 and December 2019.

Results

An antibiotic was given in 27 183 of the 76 027 (35.8%) episodes of fever. The incidence of fever-related antibiotic use was 58.0 (95% confidence interval [CI], 57.2–58.6) per 100 child-years. The median time to initiation of antibiotics was 4 days, and in 65% of those who received an antibiotic it was initiated by the second day. Antibiotics were continued for &lt;3 days in 24% of the episodes. Higher temperature, younger age, male sex, joint family, higher education, internet access, and availability of personal conveyance were associated with antibiotic treatment for fever.

Conclusions

In developing countries where antibiotic use is not regulated, broad-spectrum antibiotics are initiated early, and often inappropriately, in febrile illness. Frequent and inappropriate use of antibiotics may increase risk of antimicrobial resistance.

Nanotechnology-Based Delivery Systems for Antimicrobial Peptides

Antimicrobial resistance (AMR) is a significant threat to global health. The conventional antibiotic pool has been depleted, forcing the investigation of novel and alternative antimicrobial strategies. Antimicrobial peptides (AMPs) have shown potential as alternative diagnostic and therapeutic agents in biomedical applications. To date, over 3000 AMPs have been identified, but only a fraction of these have been approved for clinical trials. Their clinical applications are limited to topical application due to their systemic toxicity, susceptibility to protease degradation, short half-life, and rapid renal clearance. To circumvent these challenges and improve AMP’s efficacy, different approaches such as peptide chemical modifications and the development of AMP delivery systems have been employed. Nanomaterials have been shown to improve the activity of antimicrobial drugs by providing support and synergistic effect against pathogenic microbes. This paper describes the role of nanotechnology in the targeted delivery of AMPs, and some of the nano-based delivery strategies for AMPs are discussed with a clear focus on metallic nanoparticle (MNP) formulations.

PREVALENCE AND ANTIMICROBIAL RESISTANCE PATTERNS OF SALMONELLA SPP. IN TWO FREE-RANGING POPULATIONS OF EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA)

Salmonellosis is an important zoonotic infection, and exposure to pet reptiles has been implicated in several human outbreaks. Although several studies report a low prevalence of salmonellae in free-ranging chelonians, they may serve as a reservoir. In spring and summer of 2013 and 2019, free-ranging eastern box turtles (Terrapene carolina carolina) from populations in Illinois (rural) and Tennessee (urban) were collected through canine and visual search. Cloacal swab samples were collected from each turtle, selectively enriched with tetrathionate broth, then plated on selective and differential media to isolate Salmonella spp. Genus was confirmed via MALDI-TOF MS and antibiotic sensitivities were performed. Isolates were serotyped by the National Veterinary Services Laboratory. Of the 341 turtles sampled, Salmonella spp. were detected in nine individuals (2.64%; 95% CI: 1.2-5.0%). The isolates included five different serovars: Anatum (n = 2), Newport (n = 2), Thompson (n = 1), Bareilly (n = 2), and Hartford (n = 2). Salmonella spp. were detected from six animals in 2013 (3.19%, 95% CI: 1.2-6.8%) and three in 2019 (1.96%, 95% CI: 0.4-5.6%). There was no significant difference in prevalence between state, (P = 0.115), Illinois locations (P = 0.224), season (P = 0.525), year (P = 0.297), sex (P = 0.435), or age class (P = 0.549). The health of Salmonella-positive and -negative turtles was not significantly different, as assessed through hematology and plasma biochemistry (P > 0.05), indicating asymptomatic carrier status. The low prevalence detected in this study likely concludes that free-ranging eastern box turtles play a minimal role in the spread of salmonellae. However, the identified serotypes are potentially human- and animal-pathogenic. Documenting the prevalence of Salmonella serotypes in animal indicators furthers our understanding of their spread between humans, animal agriculture, and the environment.

National Antibiotics Utilization Trends for Human Use in Tanzania from 2010 to 2016 Inferred from Tanzania Medicines and Medical Devices Authority Importation Data

Antimicrobial use (AMU) is one of the major drivers of emerging antimicrobial resistance (AMR). The surveillance of AMU, which is a pillar of AMR stewardship (AMS), helps devise strategies to mitigate AMR. This descriptive, longitudinal retrospective study quantified the trends in human antibiotics utilization between 2010 and 2016 using data on all antibiotics imported for systemic human use into Tanzania’s mainland. Regression and time series analyses were used to establish trends in antibiotics use. A total of 12,073 records for antibiotics were retrieved, totaling 154.51 Defined Daily Doses per 1000 inhabitants per day (DID), with a mean (±standard deviation) of 22.07 (±48.85) DID. The private sector contributed 93.76% of utilized antibiotics. The top-ranking antibiotics were amoxicillin, metronidazole, tetracycline, ciprofloxacin, and cefalexin. The DIDs and percentage contribution of these antibiotics were 53.78 (34.81%), 23.86 (15.44), 20.53 (13.29), 9.27 (6.0) and 6.94 (4.49), respectively. The time series model predicted a significant increase in utilization (p-value = 0.002). The model forecasted that by 2022, the total antibiotics consumed would be 89.6 DIDs, which is a 13-fold increase compared to 2010. Government intervention to curb inappropriate antibiotics utilization and mitigate the rising threat of antibiotic resistance should focus on implementing AMS programs in pharmacies and hospitals in Tanzania.

Assessment of the Knowledge and Approach of General Dentists Who Treat Children and Pediatric Dentists Regarding the Proper Use of Antibiotics for Children

Background: Antibiotics are widely used in dentistry. Dentists often provide antibiotics unnecessarily. Excessive use can induce resistant bacterial strains. There are certain indications for the proper use of antibiotics for pediatric dentistry according to the European and American Pediatric Dentistry (EAPD and AAPD). Very often dentists do not follow these guidelines. Objectives: This study aims to examine the level of knowledge among general dentists (who also treat children) and pediatric dentists on proper use of antibiotics. In addition, we examined whether there is unjustified use of antibiotics, if dentists are aware of the new and conservative approach of administering antibiotics to patients, and whether there is a relationship between years of professional seniority and dentist's knowledge level of proper use of antibiotics. Methods: One hundred general dentists (GD) who treat children in addition to 100 pediatric dentists (PD) completed the study questionnaires which measured knowledge, practice and attitudes regrading using antibiotics during dental treatment among children. Results: The general average of level of knowledge on proper use of antibiotics among general dentists was relatively low for both GD (60.7%) and PDs (65%). PDs demonstrated a relatively greater knowledge of correct use of antibiotics, especially in cases of endodontics and trauma. PDs also showed higher awareness to latest guidelines for the admission of "prophylactic antibiotics" according to the American Association (AAPD) and/or the European Union (EAPD) compared with GDs (86.2% vs. 66.3%). Conclusion: The level of knowledge of both general dentists and pediatric dentists is poor, with a large percentage of dentists from both groups not knowing whether antibiotics are needed in a specific dental case or not. Compliance with the EAPD/AAPD guidelines is also low and inadequate. The method of prescribing antibiotics given by dentists can be improved by increasing awareness, educational initiatives, and postgraduate courses among dentists regarding the recommended indications.

The Case against Antibiotics and for Anti-Virulence Therapeutics

Although antibiotics have been indispensable in the advancement of modern medicine, there are downsides to their use. Growing resistance to broad-spectrum antibiotics is leading to an epidemic of infections untreatable by first-line therapies. Resistance is exacerbated by antibiotics used as growth factors in livestock, over-prescribing by doctors, and poor treatment adherence by patients. This generates populations of resistant bacteria that can then spread resistance genes horizontally to other bacterial species, including commensals. Furthermore, even when antibiotics are used appropriately, they harm commensal bacteria leading to increased secondary infection risk. Effective antibiotic treatment can induce bacterial survival tactics, such as toxin release and increasing resistance gene transfer. These problems highlight the need for new approaches to treating bacterial infection. Current solutions include combination therapies, narrow-spectrum therapeutics, and antibiotic stewardship programs. These mediate the issues but do not address their root cause. One emerging solution to these problems is anti-virulence treatment: preventing bacterial pathogenesis instead of using bactericidal agents. In this review, we discuss select examples of potential anti-virulence targets and strategies that could be developed into bacterial infection treatments: the bacterial type III secretion system, quorum sensing, and liposomes.

Inhibition of Class A β-Lactamase (TEM-1) by Narrow Fractions of Humic Substances

Antimicrobial resistance is a global threat. The use of biologically active natural products alone or in combination with the clinically proven antimicrobial agents might be a useful strategy to fight the resistance. The scientific hypotheses of this study were twofold: (1) the natural humic substances rich in dicarboxyl, phenolic, heteroaryl, and other fragments might possess inhibitory activity against β-lactamases, and (2) this inhibitory activity might be linked to the molecular composition of the humic ensemble. To test these hypotheses, we used humic substances (HS) from different sources (coal, peat, and soil) and of different fractional compositions (humic acids, hymatomelanic acids, and narrow fractions from solid-phase extraction) for inhibiting serine β-lactamase TEM-1. Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) was used to characterize the molecular composition of all humic materials used in this study. The kinetic assay with chromogenic substrate CENTA was used for assessment of inhibitory activity. The inhibition data have shown that among all humic materials tested, a distinct activity was observed within apolar fractions of hymatomelanic acid isolated from lignite. The decrease in the hydrolysis rate in the presence of most active fractions was 42% (with sulbactam-87%). Of particular importance is that these very fractions caused a synergistic effect (2-fold) for the combinations with sulbactam. Linking the observed inhibition effects to molecular composition revealed the preferential contribution of low-oxidized aromatic and acyclic components such as flavonoid-, lignin, and terpenoid-like molecules. The binding of single low-molecular-weight components to the cryptic allosteric site along with supramolecular interactions of humic aggregates with the protein surface could be considered as a major contributor to the observed inhibition. We believe that fine fractionation of hydrophobic humic materials along with molecular modeling studies on the interaction between humic molecules and β-lactamases might contribute to the development of novel β-lactamase inhibitors of humic nature.

Antimicrobial guidelines in clinical practice: incorporating the ethical perspective

Introduction

Guidelines on antimicrobial therapy are subject to periodic revision to anticipate changes in the epidemiology of antimicrobial resistance and new scientific knowledge. Changing a policy to a broader spectrum has important consequences on both the individual patient level (e.g. effectiveness, toxicity) and population level (e.g. emerging resistance, costs). By combining both clinical data evaluation and an ethical analysis, we aim to propose a comprehensive framework to guide antibiotic policy dilemmas.

Methods

A preliminary framework for decision-making on antimicrobial policy was constructed based on existing literature and panel discussions. Antibiotic policy themes were translated into specific elements that were fitted into this framework. The adapted framework was evaluated in two moral deliberation groups. The moral deliberation sessions were analysed using ATLAS.ti statistical software to categorize arguments and evaluate completeness of the final framework.

Results

The final framework outlines the process of data evaluation, ethical deliberation and decision-making. The first phase is a factual data exploration. In the second phase, perspectives are weighed and the policy of moral preference is formulated. Judgments are made on three levels: the individual patient, the patient population and society. In the final phase, feasibility, implementation and re-evaluation are addressed.

Conclusions

The proposed framework facilitates decision-making on antibiotic policy by structuring existing data, identifying knowledge gaps, explicating ethical considerations and balancing interests of the individual and current and future generations.

Antibiotic-Dispensing Practice in Community Pharmacies: Results of a Cross-Sectional Study in Italy

Inappropriate use of antibiotics in the community contributes to the development of antibiotic resistance (ABR), one of the most concerning issues in modern medicine. The objectives of the study were to investigate the knowledge and attitudes regarding ABR and dispensing antibiotics without prescription (DAwP) and to assess the extent of the practice of DAwP among Italian community pharmacists (CPs). A nationwide cross-sectional study using an anonymous, structured, validated, and pilot-tested questionnaire was conducted. The five sections gathered data on demographic and professional characteristics, knowledge and attitudes toward ABR and DAwP, practices regarding dispensing antibiotics with or without prescription and their reasons, counselling on the potential antibiotic side effects and the importance of adherence to medication regimen, and the information sources used to update the knowledge about ABR. About 4 in 10 CPs (37.1%) reported being involved in DAwP, although 93.7% knew that it is illegal in Italy. The vast majority affirmed to have always/often asked clients about their drug allergies (95.5%) and about their medication history (82.5%). Two-thirds (66.2%) warned their clients about the potential side effects of the drugs, and 55% informed them about the importance of completing the full course of antibiotics. Complacency with clients who found it difficult to consult the physician was the most significant predictor of DAwP. A considerable proportion of DAwP was described, so it could be easy for patients to misuse these drugs. Future policies need to enhance the enforcement of existing prescription-only regulations and to develop monitoring strategies to ensure their establishment in real-life practices.

Antimicrobial stewardship solutions with a smart innovative tool

BACKGROUND

Antimicrobial consumption has been increasing lately. Hence, effective strategies are required to control antimicrobial use and decrease the development of antimicrobial resistance.

OBJECTIVE

To evaluate the impact of the use of a mobile app on the implementation of antimicrobial stewardship program (ASP) interventions.

METHODS

This was a longitudinal study conducted at El-Nile Badrawi Hospital in Cairo, Egypt, on inpatients receiving antimicrobials from January 2018 to December 2019. The study included 2 phases: the preimplementation phase, which included a paper-based ASP developed according to the Centers for Disease Control and Prevention Core Elements of Hospital Antibiotic Stewardship Programs 2014, and the mobile app phase where the MEDIcare Pro mobile app was developed and used in ASP intervention implementation. The study outcomes were antimicrobial consumption and cost, length of hospital and intensive care unit (ICU) stay, 30-day mortality rate and readmission rate, and detection of drug-related problems (DRPs).

RESULTS

The mobile app statistically significantly decreased antimicrobial consumption from 75.1 defined daily dose (DDD)/100 bed-days in the preimplementation phase to 64.65 DDD/100 bed-days in the mobile app phase, with a total cost savings of E£1,237,476. There was a significant reduction in the length of ICU stay, with a mean difference of 1.63 days between the 2 phases, but no significance was detected regarding length of hospital stay or readmission rate. There was a statistically significant decrease in mortality rate from 1.17% in the preimplementation phase to 0.83% in the mobile app phase (P = 0.02). The frequency of DRPs detected by pharmacists statistically significantly increased from 0.54/100 bed-days in the preimplementation phase to 3.23/100 bed-days in the mobile app phase.

CONCLUSION

The use of a mobile app was found to be effective, applicable, and usable in guiding health professionals on rational antimicrobial use.

Electrochemically controlled solid phase microextraction based on a conductive polyaniline-graphene oxide nanocomposite for extraction of tetracyclines in milk and water

BACKGROUND

Tetracycline antibiotics are employed for human and animal health and for speeding up growth rates. However, their presence in food products and environmental waters has been a concern for some years. Therefore, a variety of sample preparation methods have been developed for the analysis of tetracycline residues in these matrices.

RESULTS

An electrochemically controlled solid phase microextraction based on a modified copper electrode with polyaniline/graphene oxide (PANI/GO) conductive nanocomposite was developed for the extraction of oxytetracycline, tetracycline and doxycycline before high-performance liquid chromatography-UV analysis. PANI/GO was synthesized by in situ chemical oxidative polymerization, characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy, and bound on the electrode using high purity conductive double-sided adhesive carbon glue. The significant factors affecting the performance of microextraction were investigated and optimized. Under the optimized conditions [sample, 15 mL; sorbent, 10 mg; pH, 3.0; electroextraction voltage, -0.9 V; electroextraction time, 20 min; eluent (MeOH/NH₃ ), 500 μL; and desorption time, 5 min], the limits of detection for target analytes were in the ranges 0.32-1.01 and 2.42-7.59 μg L^-1 in water and milk samples, respectively. The linear ranges were 1.06-750 μg L^-1 for water and 8.05-750 μg L^-1 for milk samples. The intra-day and inter-day precisions were 2.32-3.80 and 3.29-4.25, respectively. The method was applied to the determination of analytes in milk and water samples with different fat contents, and the recoveries were obtained in the range 71-104%.

CONCLUSION

The developed electro-microextraction method provides a facile, rapid, cost-effective, sensitive and efficient promising procedure for the extraction of antibiotics in complex matrices. © 2020 Society of Chemical Industry.

Simultaneous elucidation of antibiotic mechanism of action and potency with high-throughput Fourier-transform infrared (FTIR) spectroscopy and machine learning

The low rate of discovery and rapid spread of resistant pathogens have made antibiotic discovery a worldwide priority. In cell-based screening, the mechanism of action (MOA) is identified after antimicrobial activity. This increases rediscovery, impairs low potency candidate detection, and does not guide lead optimization. In this study, high-throughput Fourier-transform infrared (FTIR) spectroscopy was used to discriminate the MOA of 14 antibiotics at pathway, class, and individual antibiotic level. For that, the optimal combinations and parametrizations of spectral preprocessing were selected with cross-validated partial least squares discriminant analysis, to which various machine learning algorithms were applied. This coherently resulted in very good accuracies, independently of the algorithms, and at all levels of MOA. Particularly, an ensemble of subspace discriminants predicted the known pathway (98.6%), antibiotic classes (100%), and individual antibiotics (97.8%) with exceptional accuracy, and similar results were obtained for simulated novel MOA. Even at very low concentrations (1 μg/mL) and growth inhibition (15%), over 70% pathway and class accuracy was achieved, suggesting FTIR spectroscopy can probe the grey chemical matter. Prediction of inhibitory effect was also examined, for which a squared exponential Gaussian process regression yielded a root mean square error of 0.33 and a R² of 0.92, indicating that metabolic alterations leading to growth inhibition are intrinsically reflected on FTIR spectra beyond cell density. KEY POINTS: • Antibiotic MOA and potency estimated with high-throughput FTIR spectroscopy • Sub-inhibitory MOA identification suggests ability to explore grey chemical matter • Data analysis optimization improved MOA identification at antibiotic level by 38.

The Not-So-Strange Case of Dr. Jekyll and Mr. Hyde in Antibiotic Research: An Interdisciplinary Opportunity

Literary-rhetorical devices like figurative language and analogy can help explain concepts that exceed our capacity to grasp intuitively. It is not surprising these devices are used to discuss virulence, pathogenesis, and antibiotics. Allusions to Robert Louis Stevenson’s Strange Case of Dr. Jekyll and Mr. Hyde seem to be used with particular frequency in research pertaining to pathogens, especially in studies contemporary with our evolving understanding of antibiotic resistance. More recent references to the text have appeared in research parsing definitions of virulence and acknowledging the role of anti-virulence in future therapeutics. While it is obvious that scientists invoke Stevenson’s story for stylistic purposes, its use could go beyond the stylistic—and might even generate rhetorical and imaginative possibilities for framing research. This perspective discusses the first published allusion to Jekyll and Hyde in reference to virulence and pathogenesis; comments on a select number of specific instances of Jekyll and Hyde in contemporary scientific literature; briefly contextualizes the novel; and concludes with the implications of a more productive engagement with humanistic disciplines in the face of antibiotic resistance.

Antimicrobial Resistance in Pathogens Isolated from Blood Cultures: A Two-Year Multicenter Hospital Surveillance Study in Italy

Background: Antimicrobial resistance (AMR) is one of the most concerning issues in medicine today. The objectives of this study were to investigate the AMR distribution of the blood-borne pathogens isolated over a two-year period in an Italian region. Methods: A retrospective electronic record review of laboratory-confirmed bloodstream infections (BSIs) was done, and data from three major diagnostic laboratories were used. Twelve invasive clinically important bacteria species were included in the sample. Results: During the study period, 1228 positive BSIs were collected. The most common pathogens were Coagulase-negative Staphylococcus (CoNS) (29.7%), Staphylococcus aureus (19.1%) and Escherichia coli (15.9%). With regard to the AMR pattern, 31.7% of CoNS and 28.1% of Staphylococcus aureus were oxacillin-resistant, and almost half of the Enterococci showed resistance to high-level gentamicin. Among Gram-negative species, 11.7% of Escherichia coli and 39.5% of Klebsiella pneumoniae were carbapenem-resistant. Among the non-fermentative Gram-negative bacteria, the most frequently combined AMR pattern was aminoglycosides and fluoroquinolones (48.4% in A. baumannii and 14.6% in P. aeruginosa). Conclusion: The results display an alarming prevalence of AMR among hospital isolated pathogens, consistently higher than the European average. Information from surveillance systems to better characterize the trend in the incidence of AMR at local and national levels is needed.

Investigating the relationship between extended spectrum β-lactamase producing Escherichia coli in the environment and food chains with the presence of this infection in people suspected of septicemia: Using the fuzzy set qualitative comparative analysis

PROPOSE

Among antibiotic resistance cases, resistance to β-lactam antibiotics is a major concern for the treatment of microbial infections. Furthermore, the prevalence of extended-spectrum β-lactamases (ESBL) Escherichia coli (E. coli) in environment, food, and human resources of Iran has increased over the past few years. This study aimed to predict the relationship between the prevalence of ESBL E. coli in the environment and the food chains with the presence of this infection in people suspected of septicemia using fuzzy set qualitative comparative analysis model.

METHODS

In this analytical cross sectional study samples were collected from the environment (hospital sewage, downstream and upstream urban sewage, and slaughterhouse sewage), food (chicken), and human chains (people suspected of septicemia) in Tehran province, Iran. This study was conducted from September to February 2019 and the prevalence of ESBL E. coli was calculated in each resource. Then, the relationship between the prevalence of ESBL E. coli in the environment and food chains and its prevalence in the human chain was predicted using the fuzzy set qualitative comparative analysis.

RESULTS

The results showed the prevalence of ESBL E. coli in those suspected of septicemia in September, October, November, December, January and February was 58.1%, 60%, 33.3%, 100%, 43%, and 57.8%, respectively. Also, the results of the fuzzy set qualitative comparative analysis indicated hospital wastewater and chicken contamination with ESBL E. coli were the main causes of contamination with ESBL E. coli in people suspected of septicemia.

CONCLUSIONS

According to the results of this study, if there is a contamination of hospital wastewater and chickens in an area, it can be claimed that people suspected of septicemia are infected with ESBL E. coli, and the percentage of this contamination can be high. On the other hand, controlling ESBL E. coli in hospital wastewater (environmental chain) and chickens (food chain) can prevent contamination in people with suspected septicemia.

Effects of Antibiotics upon the Gut Microbiome: A Review of the Literature

The human gastrointestinal tract carries a large number of microorganisms associated with complex metabolic processes and interactions. Although antibiotic treatment is crucial for combating infections, its negative effects on the intestinal microbiota and host immunity have been shown to be of the utmost importance. Multiple studies have recognized the adverse consequences of antibiotic use upon the gut microbiome in adults and neonates, causing dysbiosis of the microbiota. Repeated antibiotic treatments in clinical care or low-dosage intake from food could be contributing factors in this issue. Researchers in both human and animal studies have strived to explain this multifaceted relationship. The present review intends to elucidate the axis of the gastrointestinal microbiota and antibiotics resistance and to highlight the main aspects of the issue.

The Impact of an Antibiotic Stewardship Program on the Consumption of Specific Antimicrobials and Their Cost Burden: A Hospital-wide Intervention

Background

Inappropriate use of antimicrobials (AM) is a major concern worldwide that leads to the propagation of antimicrobial resistance (AMR). In addition to its clinical implications, AMR imposes an economic burden on communities, especially developing countries with more infectious diseases and less available resources. Antimicrobial stewardship programs (ASPs) have been found to be effective in reducing AMR. This study was designed to evaluate the effect of implementing an ASP in reducing AM consumption, its economic burden, and AMR as a consecutive result.

Materials and Methods

Consumption of caspofungin, amphotericin B, voriconazole, colistin, linezolid, vancomycin, and carbapenems was compared in a prospective cross-sectional study between two time periods introduced as pre- and post-ASP. Drug use density presented as anatomical therapeutic chemical (ATC)/defined daily doses (DDD) and normalized per 1000 bed days, cost savings, and AMR patterns were evaluated.

Results

A total of 9400 AM prescriptions were analyzed during a 2-year period. Consumption measured in DDD/1000 bed days dropped by 24.8, 25.0, 35.3, 47.0, 39.2, 10.5, and 23.2 percent for amphotericin B, caspofungin, colistin, voriconazole, meropenem, imipenem, and vancomycin, respectively. Linezolid consumption increased by 26.8% after implementing ASP. The expenditure of target AMs in the average value of USD decreased by 41.3% after the intervention compared to the time before using ASP (P-value=0.001). Implementing ASP also increased AM susceptibility of Pseudomonas aeruginosa, while the susceptibility of methicillin-resistant Staphylococcus aureus did not change significantly.

Conclusion

The results of this study suggest that establishment of ASP can lead to a reduction in improper administration of AMs and their expenditure resulting in economic benefit and lowering AMR at hospitals with minimum resources. Clinical pharmacists' role was critical to the success of this ASP and was uniquely empowered at our center.

Antibiotic Prescribing in Primary Care for Urinary Tract Infections (UTIs) in Pregnancy: An Audit Study

Urinary tract infections (UTIs) are associated with negative pregnancy outcomes and are treated with antibiotics. Although beneficial, antibiotic use causes antimicrobial resistance (AMR), and therefore their use needs to be carefully balanced. Antimicrobial guidelines are developed to facilitate appropriate prescribing of antibiotics. This study assessed antibiotic prescribing for UTIs in pregnancy against the National Institute for Health and Care Excellence (NICE) guideline NG109. Fifty antibiotic prescribing records dated from 1st October 2018 to 1st July 2019 were identified from three London-based GP practices. The results show that a mid-stream sample of urine, which is important for the review and tailoring of antibiotic treatment, was collected in 77.6% of cases. Prescribing the first-line antibiotic is important for adequate treatment and good antimicrobial stewardship and results show that 44% of prescriptions were for the first-choice antibiotic. Most prescriptions (56%) were for a second-line or non-recommended antibiotic. Providing self-care advice is key to empowering pregnant women in managing their own health but only 16% of records documented provision of self-care advice. This study highlights important areas of concern in the management of UTIs in pregnancy. However, due to the retrospective design, future work is needed to evaluate the role of AMR in the prescriber’s treatment decision-making process.

Perceptions of Responsibility for Antibiotic Resistance: Implications for Stewardship Campaigns

Widespread public engagement with antibiotic stewardship is essential to stem the rising incidence of antibiotic-resistant infections; however, campaigns that focus on increasing knowledge have not been effective. Beliefs about who is responsible for causing and solving antibiotic resistance (AR) likely influences engagement in antibiotic stewardship behaviors. This study assesses the U.S. public's AR causal and solution responsibility attributions and the capacity for changing these attributions to inform future antibiotic stewardship campaigns. U.S. participants (N= 1,014) diverse across race, education, and geographic region were surveyed on their beliefs about responsibility for AR for themselves, the general public, healthcare providers, scientists, and drug companies. Substantial percentages of participants held causal and solution beliefs about antibiotic resistance that likely inhibit antibiotic stewardship behaviors. Participants' beliefs that they and the general public are responsible for causing and solving AR were lower than their beliefs that healthcare providers, scientists, and drug companies are responsible. Beliefs about causal responsibility for any given person or group were significantly and positively associated with beliefs about solution responsibility for that same person or group. Responsibility beliefs differed by age, education level, and racial/ethnic background. Results highlight the need for antibiotic stewardship campaigns to incorporate responsibility attribution messaging to motivate stewardship.

[Phenotypical antibiotic resistances of bacteriological isolates originating from pet, zoo and falconry birds]

OBJECTIVE

The prevalence of resistant bacteria in pet birds, zoo birds and falconry birds is still largely unknown. Therefore, antibiograms of rapidly-growing aerobic bacteria obtained from these birds were retrospectively evaluated.

MATERIAL AND METHODS

Between 2007 and 2016 a total of 1036 antibiograms were evaluated. The bacteria isolates originated from 811 birds of 20 zoological orders (mostly Psittaciformes [61.8 %] and Passeriformes [14.5 %] and from alive patients or pathological examinations. The birds were primarily kept in Southern Germany. Phenotypic in vitro sensitivity of bacterial isolates to various antibiotics was determined using a standardized agar diffusion test.

RESULTS

The most frequently examined bacteria species were Escherichia coli (n = 386 isolates), Staphylococcus (S.). aureus (n = 150), Enterobacter cloacae (n = 122), Klebsiella pneumoniae (n = 86) and Pseudomonas aeruginosa (n = 64). Resistance to at least one antibiotic agent was detected in 53.1 % of the E. coli isolates, most commonly to doxycycline (50.3 %) and ampicillin (46.1 %), as well as in 95.9 % of Enterococcus faecalis isolates and 78.0 % of Staphylococcus aureus isolates. Multidrug resistance to 3 or more antibiotic groups was frequent in S. aureus (37.3 % of isolates). Resistance rates were higher in isolates from pet birds and captive birds of prey than in isolates from zoo birds.Resistant isolates were more common in Psittaciformes than in Passeriformes. An increasing resistance rate for fluoroquinolones in E. coli (a minimum of 0 % in 2005 and a maximum of 27.3 % in 2011) and decreasing resistance rates for tetracyclines in S. aureus (a maximum of 38.2 % in 2007 and lowest values of 0 % in 2014 and 2015) were observed over the examined period.

CONCLUSION AND CLINICAL RELEVANCE

The detected resistance rates of bacteria in pet birds, zoo birds and falconry birds must be considered as being problematic. They indicate the importance of microbial sensitivity testing for a conscientious therapy of pet birds, zoo birds and falconry birds. Critical treatment situations may arise from infections with S. aureus.

Communicating Antibiotic Stewardship: Emotional Responses and Their Impact on Adherence

Although watchful watching has been recommended as a means of reducing unnecessary use of antibiotics, nonadherence has frequently been observed. Drawing from appraisal theories of emotion, this study (n = 579) examined (a) the factors that shape pediatric caregivers' emotional experiences in the medical contexts and (b) the influence of emotions on (non)adherence behavioral intentions. Caregivers reported more intense negative emotions and less intense positive emotions following watchful waiting advice versus receiving an antibiotic prescription. The differences were mostly driven by false beliefs about antibiotics' effectiveness. Emotional responses predicted intentions to adhere to watchful waiting advice (e.g., counterargue and seek another healthcare provider), with anger being the most consistent determinant of these outcomes. Improving antibiotic stewardship can be achieved by educational efforts to correct false beliefs and by training healthcare providers to manage caregiver emotions.

Quantitative Determination of Dark and Light-Activated Antimicrobial Activity of Poly(Phenylene Ethynylene), Polythiophene, and Oligo(Phenylene Ethynylene) Electrolytes

Much recent effort has been directed toward the development of novel antimicrobial materials able to defeat new and antibiotic resistant pathogens. In this report, we study the efficacy of cationic poly(phenylene ethynylene), polythiophene, and oligo(phenylene ethynylene) electrolytes against laboratory strains of Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus epidermidis. The focus of the study is to quantitatively evaluate the speed and extent of dark and light-activated antimicrobial activity. Using cell plating with serial dilutions, we determined that planktonic bacteria suspensions exposed to the antimicrobials (at 10 μg/mL) result in several log kills at 10 min both in the dark and under UV irradiation (360 nm) for all eight synthetic antimicrobials. However, there are significant differences in the ease of killing the different pathogens. In most trials, there is significantly greater killing under light-irradiation, indicating these materials may be used as versatile disinfectants.

Targeting Perceptions of Risk from Injudicious Antibiotic Use: An Application of the Risk Information Seeking and Processing Model

Enhancing knowledge about antibiotic-associated risks is key to reducing injudicious antibiotic use and slowing antibiotic resistance. Using the Risk Information Seeking and Processing (RISP) model, the study identified predictors of individuals' seeking and avoidance of information about antibiotic risks and tested the effectiveness of exposure to a RISP-informed video intervention against exposure to a CDC-produced video and a control group. In a national sample (N = 1000), risk judgment led to greater negative affect toward risks of antibiotics and lower positive affect toward antibiotic usefulness. In turn, positive and negative affect shaped information insufficiency, which interacted with perceived information gathering capacity to influence risk information seeking and avoidance. In addition, informational subjective norms and affective responses directly shaped individuals' information behavior. Results showed that relative to the control group, participants viewing the RISP-informed video had greater risk judgment, perceived current knowledge about antibiotic risks, perceived information gathering capacity, and informational subjective norms, as well as lower levels of positive affect toward antibiotics. The RISP-informed video and CDC-produced video performed equivalently well. Implications of the findings for the design of antibiotic stewardship messages are discussed.

Precise Persuasion: Investigating Incentive Appeals for the Promotion of Antibiotic Stewardship with Message-induced Transitions

Two different lines of research-interpersonal resistance and public campaign design-lead us to consider the use of incentive appeals to motivate behavior change, with a call for greater attention to and use of positive incentives. This study tests the potential to promote antibiotic stewardship through microbiome benefits. In addition, multiple analyses were used: A causal analysis allowed us to identify what moved (e.g., which beliefs and intentions), a latent transition analysis allowed us to reveal who moved (targets, nontargets, or both), and a Markov model allowed us to estimate the stable state of these moves or, in other words, where and how the repetition of the messages would ultimately lead in terms of transitions from state to state. An experiment (N = 298), grounded in the context of antibiotic stewardship, showed that incentive appeals moved people with problematic patterns of past behavior (categorized as Persuaders, Stockers, and Dissenters) to positive patterns of behavioral intentions (categorized as Stewards). The causal analysis, latent class analysis, and equilibrium values for the separate transition matrices showed the relative benefit for a message that highlighted the health and wellness benefits of the microbiome. Implications for persuasion theory and practice are discussed.

Diastereopure Synthesis of Novel Cyclohexane-Ring-Based Constrained Lanthionine and α-Methyllanthionine through an SN2 Reaction with a β-Bromoalanine as a Key Step

Here we report the diastereopure synthesis of a novel protected lanthionine derivative substituted with a cyclohexane ring as well as the diastereopure synthesis of an α-methyllanthionine derivative. By starting from enantiopure α,β-cyclohexane-substituted cystine, or α-methylcysteine, we designed a straightforward route that permits the preparation of orthogonally protected modified lanthionines in diastereopure form. The key step of the methodology is the formation of a thioether bond through the use of an β-bromoalanine derivative. The strategy developed should be valuable in the preparation of a wide range of modified constrained lanthionines that might be finally attached to a peptide sequence, which would be especially useful in the syntheses of novel lantibiotics.

Prevention of antibiotic resistance - an epidemiological scoping review to identify research categories and knowledge gaps

BACKGROUND

Antibiotics have become the cornerstone for the treatment of infectious diseases and contributed significantly to the dramatic global health development during the last 70 years. Millions of people now survive what were previously life-threatening infections. But antibiotics are finite resources and misuse has led to antibiotic resistance and reduced efficacy within just a few years of introduction of each new antibiotic. The World Health Organization rates antibiotic resistance as a 'global security threat' impacting on global health, food security and development and as important as terrorism and climate change.

OBJECTIVES

This paper explores, through a scoping review of the literature published during the past 20 years, the magnitude of peer-reviewed and grey literature that addresses antibiotic resistance and specifically the extent to which "prevention" has been at the core. The ultimate aim is to identify know-do gaps and strategies to prevent ABR.

METHODS

The review covers four main data bases, Web of Science, Medline, Scopus and Ebsco searched for 2000-17. The broader research field "antibiotic OR antimicrobial resistance" gave 431,335 hits. Narrowing the search criteria to "Prevention of antibiotic OR antimicrobial resistance" resulted in 1062 remaining titles. Of these, 622 were unique titles. After screening of the 622 titles for relevance, 420 abstracts were read, and of these 282 papers were read in full. An additional 53 references were identified from these papers, and 64 published during 2018 and 2019 were also included. The final scoping review database thus consisted of 399 papers.

RESULTS

A thematic structure emerged when categorizing articles in different subject areas, serving as a proxy for interest expressed from the research community. The research area has been an evolving one with about half of the 399 papers published during the past four years of the study period. Epidemiological modelling needs strengthening and there is a need for more and better surveillance systems, especially in lower- and middle-income countries. There is a wealth of information on the local and national uses and misuses of antibiotics. Educational and stewardship programmes basically lack evidence. Several studies address knowledge of the public and prescribers. The lessons for policy are conveyed in many alarming reports from national and international organizations.

CONCLUSIONS

Descriptive rather than theoretical ambitions have characterized the literature. If we want to better understand and explain the antibiotic situation from a behavioural perspective, the required approaches are lacking. A framework for an epidemiological causal web behind ABR is suggested and may serve to identify entry points for potential interventions.