Antibiotic selection pressure and resistance in Streptococcus pneumoniae and Streptococcus pyogenes

Distribution of antibiotic resistance genes on chromosomes, plasmids and phages in aerobic biofilm microbiota under antibiotic pressure

The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes (ARGs) for blocking their environmental dissemination. The distribution of ARGs in chromosomes, plasmids, and phages for understanding their respective contributions to the development of antimicrobial resistance in aerobic biofilm consortium under increasing stresses of oxytetracycline, streptomycin, and tigecycline were revealed based on metagenomics analysis. Results showed that the plasmids harbored 49.2 %-83.9 % of resistomes, which was higher (p < 0.001) than chromosomes (2.0 %-35.6 %), and no ARGs were detected in phage contigs under the strict alignment standard of over 80 % identity used in this study. Plasmids and chromosomes tended to encode different types of ARGs, whose abundances all increased with the hike of antibiotic concentrations, and the variety of ARGs encoded by plasmids (14 types and 64 subtypes) was higher than that (11 types and 27 subtypes) of chromosomes. The dosing of the three antibiotics facilitated the transposition and recombination of ARGs on plasmids, mediated by transposable and integrable transfer elements, which increased the co-occurrence of associated and unassociated ARGs. The results quantitatively proved that plasmids dominate the proliferation of ARGs in aerobic biofilm driven by antibiotic selection, which should be a key target for blocking ARG dissemination.

Antibiotic-perturbed microbiota and the role of probiotics

The disruptive effect of antibiotics on the composition and function of the human microbiota is well established. However, the hypothesis that probiotics can help restore the antibiotic-disrupted microbiota has been advanced, with little consideration of the strength of evidence supporting it. Some clinical data suggest that probiotics can reduce antibiotic-related side effects, including Clostridioides difficile-associated diarrhoea, but there are no data that causally link these clinical effects to microbiota protection or recovery. Substantial challenges hinder attempts to address this hypothesis, including the absence of consensus on the composition of a 'normal' microbiota, non-standardized and evolving microbiome measurement methods, and substantial inter-individual microbiota variation. In this Review, we explore these complexities. First, we review the known benefits and risks of antibiotics, the effect of antibiotics on the human microbiota, the resilience and adaptability of the microbiota, and how microbiota restoration might be defined and measured. Subsequently, we explore the evidence for the efficacy of probiotics in preventing disruption or aiding microbiota recovery post-antibiotic treatment. Finally, we offer insights into the current state of research and suggest directions for future research.

In Silico Identification of Potential Clovibactin-like Antibiotics Binding to Unique Cell Wall Precursors in Diverse Gram-Positive Bacterial Strains

The rise in multidrug-resistant bacteria highlights the critical need for novel antibiotics. This study explores clovibactin-like compounds as potential therapeutic agents targeting lipid II, a crucial component in bacterial cell wall synthesis, using in silico techniques. A total of 2624 clovibactin analogs were sourced from the PubChem database and screened using ProTox 3.0 software based on their ADME-Tox properties, prioritizing candidates with favorable pharmacokinetic profiles and minimal toxicity. Molecular docking protocols were then employed to assess the binding interactions of the selected compounds with lipid II. Our analysis identified Compound 22 as a particularly promising candidate, exhibiting strong binding affinity, stable complex formation, and high selectivity for the target. Binding energy analysis, conducted via molecular dynamics simulations, revealed a highly negative value of -25.50 kcal/mol for Compound 22, surpassing that of clovibactin and underscoring its potential efficacy. In addition, Compound 22 was prioritized due to its exceptional binding affinity to lipid II and its favorable ADME-Tox properties, suggesting a lower likelihood of adverse effects. These characteristics position Compound 22 as a promising candidate for further pharmacological development. While our computational results are encouraging, experimental validation is essential to confirm the efficacy and safety of these compounds. This study not only advances our understanding of clovibactin analogs but also contributes to the ongoing efforts to combat antimicrobial resistance through innovative antibiotic development.

Structural basis for the ligand promiscuity of the hydroxamate siderophore binding protein FtsB from Streptococcus pyogenes

Pathogenic bacteria must secure the uptake of nutritional metals such as iron for their growth, making their import systems attractive targets for the development of new antimicrobial modalities. In the pathogenic bacterium Streptococcus pyogenes, the iron uptake system FtsABCD transports iron encapsulated by siderophores of the hydroxamate class. However, the inability of S. pyogenes to produce these metabolites makes the biological and clinical relevance of this route unresolved. Herein, we demonstrated that the periplasmic binding protein FtsB recognizes not only the hydroxamate siderophore ferrichrome, as previously documented, but also ferrioxamine E (FOE), ferrioxamine B (FOB), and bisucaberin (BIS), each of them with high affinity (nM level). Up to seven aromatic residues in the binding pocket accommodate the variable backbones of the different siderophores through CH-π interactions, explaining ligand promiscuity. Collectively, our observations revealed how S. pyogenes exploits the diverse xenosiderophores produced by other microorganisms as iron sources to secure this precious nutrient.

Affinity of cefditoren for penicillin-binding proteins in bacteria and its relationship with antibiotic sensitivity

Penicillin-binding proteins (PBPs) are the targets of β-lactam antibiotics; however, changes in the affinity of PBPs for beta-lactam antibiotics often affect the susceptibility of bacteria to antibiotics. The purpose of this study was to elucidate the mechanism by which cefditoren, an oral third-generation cephalosporin, binds PBPs. The minimal inhibitory concentration (MIC), bactericidal curves, and inhibition zone comparisons were assessed to evaluate the antibacterial activity of cefditoren. PBP1A and PBP2X proteins from Streptococcus pneumoniae were purified, and their ability to bind to cefditoren was investigated via microscale thermophoresis. The Kd of cefditoren toward PBP1A was 0.005 ± 0.004 µM, which was lower than those of other cephalosporins (cefcapene, cefixime and cefdinir). In contrast, the Kd of cefditoren toward PBP2X of S. pneumoniae was 9.70 ± 8.24 µM, which was lower than that of cefixime but higher than those of cefcapene and cefdinir. Additionally, the biotinylated ampicillin (BIO-AMP) method was employed to evaluate the affinity of cefditoren toward PBPs of Haemophilus influenzae, and the results demonstrated that cefditoren and PBP3A/B had the lowest IC50 values (0.060 ± 0.002 µM). These findings indicate that cefditoren has a strong affinity for PBP1A of H. influenzae. Cefditoren has a high affinity toward the PBP1As of S. pneumoniae and PBP1A and PBP3A/B of H. influenzae, which may contribute to the effective antibacterial effects of cefditoren against clinical strains and its low propensity for inducing resistance. The data presented in this article help elucidate the mechanism by which cefditoren, an oral third-generation cephalosporin, binds to PBPs and provide theoretical support for the wider use of cefditoren as an antibiotic therapy.

Incidence and variability in receipt of phenotype-desirable antimicrobial therapy for Enterobacterales bloodstream infections among hospitalized United States patients

Background

Using a large, geographically diverse, hospital-based database in the United States (Premier PINC AI Healthcare Database), we aimed to describe the proportion and characteristics of patients receiving phenotype-desirable antimicrobial therapy (PDAT) among those hospitalized with Enterobacterales bloodstream infections.

Methods

Adult patients with an admission between January 1, 2017 and June 30, 2022 with ≥1 blood culture positive for Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, or Proteus mirabilis and receiving an empiric antibiotic therapy on blood culture collection (BCC) Days 0 or 1 were included. Receiving PDAT (defined as receipt of any antimicrobial categorized as "desirable" for the respective phenotype) on BCC Days 0-2 was defined as receiving early PDAT.

Results

Among 35,880 eligible patients, the proportion of patients receiving PDAT increased (from 6.8% to 22.8%) from BCC Day 0-4. Patients who received PDAT (8,193, 22.8%) were more likely to visit large (500 + beds, 36% vs 31%), teaching (45% vs 39%), and urban (85% vs 82%) hospitals in the Northeast (22% vs 13%) compared to patients not receiving PDAT (all P <. 01). Among patients receiving PDAT, 61.4% (n = 5,033) received it early; they had a lower mean comorbidity score (3.2 vs 3.6), were less likely to have severe or extreme severity of illness (71% vs 79%), and were less likely to have a pathogen susceptible to narrow-spectrum β-lactams (31% vs 71%) compared to patients in the delayed PDAT group (all P < .01).

Conclusions

The proportion of patients receiving desirable therapy increased between BCC Day 0 and 4. Receipts of PDAT and early PDAT were associated with hospital, clinical, and pathogen characteristics.

Impact of a package of point-of-care diagnostic tests, a clinical diagnostic algorithm and adherence training on antibiotic prescriptions for the management of non-severe acute febrile illness in primary health facilities during the COVID-19 pandemic in Burkina Faso

OBJECTIVE

To assess the impact of an intervention package on the prescription of antibiotic and subsequently the rate of clinical recovery for non-severe acute febrile illnesses at primary health centers.

METHODS

Patients over 6 months of age presenting to primary health care centres with fever or history of fever within the past 7 days were randomized to receive either the intervention package constituted of point-of-care tests including COVID-19 antigen tests, a diagnostic algorithm and training and communication packages, or the standard practice. The primary outcomes were antibiotic prescriptions at Day 0 (D0) and the clinical recovery at Day 7 (D7). Secondary outcomes were non-adherence of participants and parents/caregivers to prescriptions, health workers' non-adherence to the algorithm, and the safety of the intervention.

RESULTS

A total of 1098 patients were enrolled. 551 (50.2%) were randomized to receive the intervention versus 547 (49.8%) received standard care. 1054 (96.0%) completed follow-up and all of them recovered at D7 in both arms. The proportion of patients with antibiotic prescriptions at D0 were 33.2% (183/551) in the intervention arm versus 58.1% (318/547) under standard care, risk difference (RD) -24.9 (95% CI -30.6 to -19.2, p < 0.001), corresponding to one more antibiotic saved every four (95% CI: 3 to 5) consultations. This reduction was also statistically significant in children from 6 to 59 months (RD -34.5; 95% CI -41.7 to -27.3; p < 0.001), patients over 18 years (RD -35.9; 95%CI -58.5 to -13.4; p = 0.002), patients with negative malaria test (RD -46.9; 95% CI -53.9 to -39.8; p < 0.001), those with a respiratory diagnosis (RD -48.9; 95% CI -56.9 to -41.0, p < 0.001) and those not vaccinated against COVID-19 (-24.8% 95%CI -30.7 to -18.9, p-value: <0.001). A significant reduction in non-adherence to prescription by patients was reported (RD -7.1; 95% CI -10.9 to -3.3; p < 0.001).

CONCLUSION

The intervention was associated with significant reductions of antibiotic prescriptions and non-adherence, chiefly among patients with non-malaria fever, those with respiratory symptoms and children below 5 years of age. The addition of COVID-19 testing did not have a major impact on antibiotic use at primary health centers.

TRIAL REGISTRATION

Clinitrial.gov; NCT04081051 registered on 06/09/2019.

Antibiotic resistance and nanotechnology: A narrative review

The rise of antibiotic resistance poses a significant threat to public health worldwide, leading researchers to explore novel solutions to combat this growing problem. Nanotechnology, which involves manipulating materials at the nanoscale, has emerged as a promising avenue for developing novel strategies to combat antibiotic resistance. This cutting-edge technology has gained momentum in the medical field by offering a new approach to combating infectious diseases. Nanomaterial-based therapies hold significant potential in treating difficult bacterial infections by circumventing established drug resistance mechanisms. Moreover, their small size and unique physical properties enable them to effectively target biofilms, which are commonly linked to resistance development. By leveraging these advantages, nanomaterials present a viable solution to enhance the effectiveness of existing antibiotics or even create entirely new antibacterial mechanisms. This review article explores the current landscape of antibiotic resistance and underscores the pivotal role that nanotechnology plays in augmenting the efficacy of traditional antibiotics. Furthermore, it addresses the challenges and opportunities within the realm of nanotechnology for combating antibiotic resistance, while also outlining future research directions in this critical area. Overall, this comprehensive review articulates the potential of nanotechnology in addressing the urgent public health concern of antibiotic resistance, highlighting its transformative capabilities in healthcare.

C-reactive protein point-of-care testing in primary care-broader implementation needed to combat antimicrobial resistance

This study presents the perspective of an international group of experts, providing an overview of existing models and policies and guidance to facilitate a proper and sustainable implementation of C-reactive protein point-of-care testing (CRP POCT) to support antibiotic prescribing decisions for respiratory tract infections (RTIs) with the aim to tackle antimicrobial resistance (AMR). AMR threatens to render life-saving antibiotics ineffective and is already costing millions of lives and billions of Euros worldwide. AMR is strongly correlated with the volume of antibiotics used. Most antibiotics are prescribed in primary care, mostly for RTIs, and are often unnecessary. CRP POCT is an available tool and has been proven to safely and cost-effectively reduce antibiotic prescribing for RTIs in primary care. Though established in a few European countries during several years, it has still not been implemented in many European countries. Due to the complexity of inappropriate antibiotic prescribing behavior, a multifaceted approach is necessary to enable sustainable change. The effect is maximized with clear guidance, advanced communication training for primary care physicians, and delayed antibiotic prescribing strategies. CRP POCT should be included in professional guidelines and implemented together with complementary strategies. Adequate reimbursement needs to be provided, and high-quality, and primary care-friendly POCT organization and performance must be enabled. Data gathering, sharing, and discussion as incentivization for proper behaviors should be enabled. Public awareness should be increased, and healthcare professionals' awareness and understanding should be ensured. Impactful use is achieved when all stakeholders join forces to facilitate proper implementation.

Non-Canonical Aspects of Antibiotics and Antibiotic Resistance

The understanding of antibiotic resistance, one of the major health threats of our time, is mostly based on dated and incomplete notions, especially in clinical contexts. The "canonical" mechanisms of action and pharmacodynamics of antibiotics, as well as the methods used to assess their activity upon bacteria, have not changed in decades; the same applies to the definition, acquisition, selective pressures, and drivers of resistance. As a consequence, the strategies to improve antibiotic usage and overcome resistance have ultimately failed. This review gathers most of the "non-canonical" notions on antibiotics and resistance: from the alternative mechanisms of action of antibiotics and the limitations of susceptibility testing to the wide variety of selective pressures, lateral gene transfer mechanisms, ubiquity, and societal factors maintaining resistance. Only by having a "big picture" view of the problem can adequate strategies to harness resistance be devised. These strategies must be global, addressing the many aspects that drive the increasing prevalence of resistant bacteria aside from the clinical use of antibiotics.

Mechanism of Action and Design of Potent Antibacterial Block Copolymer Nanoparticles

Self-assembled polymer nanoparticles are promising antibacterials, with nonspherical morphologies of particular interest as recent work has demonstrated enhanced antibacterial activity relative to their spherical counterparts. However, the reasons for this enhancement are currently unclear. We have performed a multifaceted analysis of the antibacterial mechanism of action of 1D nanofibers relative to nanospheres by the use of flow cytometry, high-resolution microscopy, and evaluations of the antibacterial activity of pristine and tetracycline-loaded nanoparticles. Low-length dispersity, fluorescent diblock copolymer nanofibers with a crystalline poly(fluorenetrimethylenecarbonate) (PFTMC) core (length = 104 and 472 nm, height = 7 nm, width = 10-13 nm) and a partially protonated poly(dimethylaminoethyl methacrylate) (PDMAEMA) corona (length = 12 nm) were prepared via seeded growth living crystallization-driven self-assembly. Their behavior was compared to that of analogous nanospheres containing an amorphous PFTMC core (diameter of 12 nm). While all nanoparticles were uptaken into Escherichia coli W3110, crystalline-core nanofibers were observed to cause significant bacterial damage. Drug loading studies indicated that while all nanoparticle antibacterial activity was enhanced in combination with tetracycline, the enhancement was especially prominent when small nanoparticles (ca. 15-25 nm) were employed. Therefore, the identified differences in the mechanism of action and the demonstrated consequences for nanoparticle size and morphology control may be exploited for the future design of potent antibacterial agents for overcoming antibacterial resistance. This study also reinforces the requirement of morphological control over polymer nanoparticles for biomedical applications, as differences in activity are observed depending on their size, shape, and core-crystallinity.

Self-medication with antibiotics in Georgian population

Background: Self-medication with antibiotics is a global phenomenon and a potential contributor to human pathogen resistance to antibiotics. It involves obtaining medication without a prescription, taking medicines based on the advice of friends and relatives, or previous treatment experience. Self-medication is common in both developed and developing countries; however, the prevalence of self-medication is higher in developing countries. The aim of this study was to determine the characteristics of antimicrobial self-medication in Georgia and its potential to influence the overall situation regarding antimicrobial consumption in the country. Methods: We conducted a cross-sectional study using a random sampling method and developed a self-administered questionnaire to collect the data. The survey was conducted via the Internet using the Google Forms platform. Results: The overall number of respondents was 742 adults living in Georgia. The results showed that 23.8% (n = 177) of adults had consumed antibiotics without a doctor's prescription, and 12.7% (n = 94) confirmed the use of antibiotics by their own decision to treat minor family members. The total prevalence of self-medication was 32.6%. The data analysis revealed a correlation between factor F1 ("personal experience") and gender (p = 0.042, F = 2.6), and between age and factor F2 ("lack of trust in medical practitioners") (p = 0.047, F = 2.691). The correlation was stronger among young adults (aged 18-24) and senior adults (aged 60+). The correlation between the level of education and factor F2 was stronger (p = 0.00; F1 = 7.9) than with factor F1 (p = 0.04; F = 2.2). Conclusion: Self-medication is prevalent in Georgia; pharmacies are the main sources of antimicrobials. No correlation was found between factor F2, pertaining to "lack of trust in medical practitioners" and gender, between age and factor F1, linked to "personal experience." The study uncovered a lack of knowledge about self-medication with antibiotics and emphasized the importance of public awareness campaigns and implementing effective interventions to regulate the sales of antibiotics without a doctor's prescription.

Antimicrobial peptide-conjugated phage-mimicking nanoparticles exhibit potent bactericidal action against Streptococcus pyogenes in murine wound infection models

Streptococcus pyogenes is a causative agent for strep throat, impetigo, and more invasive diseases. The main reason for the treatment failure of streptococcal infections is increased antibiotic resistance. In recent years, infectious diseases caused by pyogenic streptococci resistant to multiple antibiotics have been rising with a significant impact on public health and the veterinary industry. The development of antibiotic resistance and the resulting emergence of multidrug-resistant bacteria have become primary threats to the public health system, commonly leading to nosocomial infections. Many researchers have turned their focus to developing alternative classes of antibacterial agent based on various nanomaterials. We have developed an antibiotic-free nanoparticle system inspired by naturally occurring bacteriophages to fight antibiotic-resistant bacteria. Our phage-mimicking nanoparticles (PhaNPs) display structural mimicry of protein-turret distribution on the head structure of bacteriophages. By mimicking phages, we can take advantage of their evolutionary constant shape and high antibacterial activity while avoiding the immune reactions of the human body experienced by biologically derived phages. We describe the synthesis of hierarchically arranged core-shell nanoparticles, with a silica core conjugated with silver-coated gold nanospheres to which we have chemisorbed the synthetic antimicrobial peptide Syn-71 on the PhaNPs surface, and increased the rapidity of the antibacterial activity of the nanoparticles (PhaNP@Syn71). The antibacterial effect of the PhaNP@Syn71 was tested in vitro and in vivo in mouse wound infection models. In vitro, results showed a dose-dependent complete inhibition of bacterial growth (>99.99%). Cytocompatibility testing on HaCaT human skin keratinocytes showed minimal cytotoxicity of PhaNP@Syn71, being comparable to the vehicle cytotoxicity levels even at higher concentrations, thus proving that our design is biocompatible with human cells. There was a minimum cutoff dosage above which there was no evolution of resistance after prolonged exposure to sub-MIC dosages of PhaNP@Syn71. Application of PhaNP@Syn71 to a mouse wound infection model exhibited high biocompatibility in vivo while showing immediate stabilization of the wound size, and infection free wound healing. Our results suggest the robust utility of antimicrobial peptide-conjugated phage-mimicking nanoparticles as a highly effective antibacterial system that can combat bacterial infections consistently while avoiding the emergence of resistant bacterial strains.

Assessment of public knowledge and attitude toward antibiotics use and resistance: a community pharmacy-based survey

BACKGROUND

Antimicrobial resistance is a public health challenge affecting all aspects of healthcare systems. Policies to reduce antimicrobial resistance should be implemented and monitored in community pharmacies, because they are patients' first point of care. Public awareness of relevant knowledge and attitudes on antimicrobials is a feasible strategy to mitigate the spread of antimicrobial resistance by exploiting the relationship between pharmacists and patients in the community pharmacy setting. The study evaluated and determined predictors of antibiotic knowledge and attitudes toward antibiotic use and resistance in community pharmacy patients.

METHODS

A cross-sectional design was used to retrieve data in five randomly selected community pharmacies in Lagos and Abuja using a self-administered questionnaire. Descriptive and inferential statistics were utilized for characterizing and determining the associations between predictors and outcomes at p < 0.05. Logistic regression was used to identify predictors of patients' knowledge and attitude to antibiotic use.

RESULTS

A total of 964 clients participated in the study: 526(54.7%) were females, and 358(37.3%) were aged 25-34. chlorpheniramine-maleate and levonorgestrel were wrongly identified as antibiotics by 621 (64%) and 490 (50%) respondents, respectively. Many respondents, 448(46.5%), strongly agree that antibiotic creams should be mixed with body creams. The result of the multivariable logistic regression showed secondary education [Odds Ratio (OR): 0.31, 95% CI 0.10-0.97, p value: 0.044], urban residence (OR: 1.45, 95% CI 1.01-2.08, p value: 0.043) and age 34 (OR: 1.55, 95% CI 1.01-2.37, p value: 0.045) were strong predictors of knowledge on antibiotics, while community pharmacy location (OR: 5.48, 95% CI 3.45-8.70, p value: ≤ 0.001), urban residence (OR: 2.57, 95% CI 1.67-3.96, p value: ≤ 0.001), and antibiotic recommender (OR: 0.55, 95% CI 0.35-0.85, p value: 0.008) were predictors of respondents' attitude to antibiotic use.

CONCLUSIONS

The study established that sociodemographic factors could impact community pharmacy clients' knowledge and attitude toward antibiotic use and resistance and should be considered when developing policies to curb the spread of resistant microbes. Community pharmacies should educate community pharmacy clients on the dangers associated with the misuse of antibiotics with stringent antibiotic stewardship programs and restrict access to antibiotics over-the-counter.

Antibiotic Use, Awareness of Antimicrobial Resistance and Residue in Veterinary Professionals and Farmers in Selected Districts of Kellem Wollega Zone, Ethiopia

Background

Antimicrobials have a crucial role in reducing mortality and morbidity in animals, but misuse of them may cause antimicrobial resistance and residues which are challenging in animal production and public health. These problems are mostly aggravated in developing countries including Ethiopia.

Objective

Assessment of antibiotic use, awareness of antimicrobial resistance and antimicrobial residue in veterinary professionals and farmers.

Methods

A cross-sectional study was conducted from September 2021 to August 2022 in three districts (Seyo, Hawa Gelan, and Dale Sadi) of the Kellem Wollega zone, selected by purposive sampling. The study population was farmers and veterinary professionals. Data was collected from a total of 312 respondents; 230 farmers and 82 veterinary professionals using interviews and questionnaires, respectively.

Results

Out of 312 total respondents, 230 (73.71%) were farmers and 82 (26.28%) were veterinary professionals. From the farmer respondents, 127 (55.22%), 153 (66.52%), and 142 (61.74%) had an awareness of antibiotics and their usage, antimicrobial resistance, and withdrawal period, respectively. Out of 82 veterinary professional respondents, 92.68% practice dose calculation during animal treatment, 79.27% diagnose systemic infections by tentative diagnosis, 85.37% have no laboratory facility for bacterial disease, and 81.71% give broad-spectrum antibiotics for undifferentiated cases. The income type of respondents looks to have a strong association (P < 0.05) with awareness of antibiotics (OR: 3.427, SE: 1.404, CI: 1.535-7.654), antimicrobial resistance (OR: 3.536, SE: 1.339, CI: 1.683-7.430) and withdrawal periods (OR: 3.297, SE: 1.267, CI: 1.552-7.004).

Conclusion

This study shows most farmers have awareness about antibiotics and their use, antimicrobial resistance, and residue but inappropriate use of antimicrobials in farmers and lack of laboratory facilities in most veterinary professionals observed.

Serotype distribution and antibiogram of Streptococcus parauberis isolated from fish in South Korea

Streptococcus parauberis is the dominant etiological agent of streptococcosis, the most devastating bacterial disease in the olive flounder farming industry in South Korea. In this study, the distribution of serotypes, antimicrobial susceptibility, and presence of antimicrobial resistance genes (ARGs) in S. parauberis isolates obtained between 1999 and 2021 was thoroughly investigated to gain insight into the dynamics of their presence and the relationship between serotypes and antimicrobial resistance. Disk diffusion testing of 103 isolates against 10 antimicrobial agents was performed, and epidemiological cut-off values generated through normalized resistance interpretation analysis were used to classify wild-type (WT) and non-wild-type (NWT) populations. Principal component analysis and hierarchical clustering were implemented to achieve an understanding on the relationship between serotypes and antimicrobial resistance patterns. PCR-based serotyping showed that serotype Ia (67.1%) was the most prevalent in South Korea, followed by serotypes Ib/Ic (25.2%) and II (7.7%). The highest proportion of isolates was assigned to NWT against amoxicillin (80.6%), followed by oxytetracycline (77.7%) and erythromycin (48.5%). The time-scale data showed that recently obtained serotypes Ib/Ic and II isolates tended to be categorized as NWT populations resistant to more antibiotics, possibly due to microbial adaptation to antibiotic pressure. ARGs responsible for resistance to oxytetracycline and erythromycin were found only in NWT populations in serotype Ia [tet(S) and erm(B), respectively], and serotype II [tet(M) and mef(J)-msr(I), respectively]. We also found that the mef-msr gene pair in S. parauberis serotype II might be involved in low-level resistance to erythromycin. IMPORTANCE This study presents serotype distribution and antimicrobial susceptibility data along with the antimicrobial resistance genes (ARGs) of Streptococcus parauberis, which is an important bacterial fish pathogen worldwide. In particular, almost all oxytetracycline and erythromycin non-wild-type (NWT) populations harbored tet(S) or tet(M), and erm(B) or mef(J)-msr(I), respectively. Interestingly, these ARGs were distributed in a highly serotype-dependent manner, resulting in a clear correlation between the antibiogram and serotype distribution. Moreover, recent isolates belonging to serotypes Ib/Ic and II tended to be more frequently categorized as NWT against antimicrobials, including amoxicillin and cefalexin compared to old isolates, while a dramatic decrease in erythromycin and clindamycin NWT frequencies was observed in recent serotype Ia isolates, which lacked erm(B). These variations might be attributed to shifts in the antibiotics employed in South Korean aquaculture over time. The overall findings would provide important background knowledge for understanding the epidemiology of S. parauberis infection in aquaculture.

"Handing out non-prescribed antibiotics is storing up trouble for the next generation!" Unpacking multistakeholder views of drivers and potential solutions in Ethiopia

BACKGROUND

Antibiotic resistance is a global health crisis, with inappropriate antibiotic use often being linked to non-prescribed antibiotic dispensing practices. This study aimed to examine the perspectives of multiple stakeholders on the drivers and potential solutions for non-prescribed antibiotic dispensing in Ethiopian community drug retail outlets (CDROs). Despite the prescription only use policies, the practice remains prevalent in Ethiopia. Many factors are thought to contribute to this issue, although little research is available for non-urban settings.

METHODS

A phenomenological qualitative study was conducted. Pharmacy professionals (owners or employees) working in non-urban towns CDROs were selected through a simulated client study, which identified CDROs that had dispensed antibiotics without a prescription. Some high-level decision makers in the Ethiopian health system were also purposively selected. Interviews were conducted in-person and over the phone or via Zoom. The interview data were transcribed verbatim, translated to English, and thematically analysed. NVivo 12 software was used to assist with coding.

RESULTS

CDRO pharmacy professionals (n = 18) and five decision makers were interviewed. Most professionals (61%) were pharmacists working in drug stores, with one to 11 years of work experience. Several contributing factors were identified at the level of patients, CDRO staff, and the healthcare system. These included economic interests, inadequate knowledge and inappropriate attitudes about antibiotic use or supply, and issues within the healthcare system included inaccessibility and insufficient capacity, absence of or a weak enforcement of prescription-only regulations or service supervision. Additionally, patient-related factors included a lack of knowledge and inappropriate attitudes about antibiotics use and their supply, previous successful treatment experience and a culture of seeking out antibiotics.

CONCLUSIONS

A complex set of modifiable factors related to patients, CDRO staff and healthcare system were identified that contribute to the non-prescribed supply of antibiotics. Due to this complexity, a single solution will not resolve the issues. Therefore, a range of multifaceted solutions have been suggested, including stricter regulation, increasing availability and accessibility of healthcare services, collaboration, and local consensus-building among CDROs, regular training for CDRO staff, and using community social events to educate the public about responsible use of antibiotics.

Antibiotic treatment durations for common infectious diseases in Switzerland: comparison between real-life and local and international guideline recommendations

OBJECTIVES

Shortening the duration of antibiotic therapy (DAT) for common infectious diseases may be an effective strategy to tackle antimicrobial resistance. Shorter DAT has been proven safe and effective for community-acquired pneumonia (CAP), cellulitis, and cholangitis.

METHODS

In a retrospective multicentre quality-control study, medical records of 770 patients hospitalized with CAP, cellulitis, and cholangitis at three tertiary care hospitals in Switzerland during 2017-2018 were randomly selected. Appropriateness of antibiotic treatment duration was assessed according to international and local guidelines.

RESULTS

Records of 271, 260, and 239 patients with CAP, cellulitis, and cholangitis were included, respectively. Median DAT was seven days (interquartile range [IQR] 6-9), ten days (IQR 8-13), and nine days (IQR 6-13) in CAP, cellulitis, and cholangitis, respectively. DAT longer than recommended by local and international guidelines was observed in 32% and 37% of CAP patients, 23% and 70% of cellulitis patients, and 33% and 37% of cholangitis patients, respectively. Positive blood cultures (odds ratio [OR] = 2.42 (95% confidence interval [CI] 1.33-4.34]), infectious diseases consultation (OR = 1.79 [95% CI 1.05-2.78]), impaired renal function (OR = 0.99 [95% CI 0.98-1.00] per 1 ml/min / 1.73 m² increase in estimated glomerular filtration rate) and a higher degree of inflammation on admission (OR = 1.0 [95% CI 1.001-1.005] per 10 mg/L increase in C-reactive protein) were independently associated with a DAT longer than recommended in international guidelines.

CONCLUSIONS

DAT exceeded recommendations in a significant proportion of patients with mostly community-acquired infections.

A new approach to overcoming antibiotic-resistant bacteria: Traditional Chinese medicine therapy based on the gut microbiota

With the irrational use of antibiotics and the increasing abuse of oral antibiotics, the drug resistance of gastrointestinal pathogens has become a prominent problem in clinical practice. Gut microbiota plays an important role in maintaining human health, and the change of microbiota also affects the activity of pathogenic bacteria. Interfering with antibiotic resistant bacteria by affecting gut microbiota has also become an important regulatory signal. In clinical application, due to the unique advantages of traditional Chinese medicine in sterilization and drug resistance, it is possible for traditional Chinese medicine to improve the gut microbial microenvironment. This review discusses the strategies of traditional Chinese medicine for the treatment of drug-resistant bacterial infections by changing the gut microenvironment, unlocking the interaction between microbiota and drug resistance of pathogenic bacteria.

An Overview of Macrolide Resistance in Streptococci: Prevalence, Mobile Elements and Dynamics

Streptococcal infections are usually treated with beta-lactam antibiotics, but, in case of allergic patients or reduced antibiotic susceptibility, macrolides and fluoroquinolones are the main alternatives. This work focuses on studying macrolide resistance rates, genetic associated determinants and antibiotic consumption data in Spain, Europe and also on a global scale. Macrolide resistance (MR) determinants, such as ribosomal methylases (erm(B), erm(TR), erm(T)) or active antibiotic efflux pumps and ribosomal protectors (mef(A/E)-mrs(D)), are differently distributed worldwide and associated with different clonal lineages and mobile genetic elements. MR rates vary together depending on clonal dynamics and on antibiotic consumption applying selective pressure. Among Streptococcus, higher MR rates are found in the viridans group, Streptococcus pneumoniae and Streptococcus agalactiae, and lower MR rates are described in Streptococcus pyogenes. When considering different geographic areas, higher resistance rates are usually found in East-Asian countries and milder or lower in the US and Europe. Unfortunately, the availability of data varies also between countries; it is scarce in low- and middle- income countries from Africa and South America. Thus, surveillance studies of macrolide resistance rates and the resistance determinants involved should be promoted to complete global knowledge among macrolide resistance dynamics.

Aminated Quinolinequinones as Privileged Scaffolds for Antibacterial Agents: Synthesis, In Vitro Evaluation, and Putative Mode of Action

Our previous studies have revealed that the aminated 1,4-quinone scaffold can be used for the development of novel antibacterial and/or antifungal agents. In this study, the aminated quinolinequinones (AQQ1-9) were designed, synthesized, and evaluated for their antimicrobial activity against a panel of seven bacterial strains (three Gram-positive and four Gram-negative bacteria) and three fungal strains. The structure-activity relationship (SAR) for the QQs was also summarized. The antibacterial activity results indicated that the two aminated QQs (AQQ6 and AQQ9) were active against Enterococcus faecalis (ATCC 29212) with a MIC value of 78.12 μg/mL. Besides, the two aminated QQs (AQQ8 and AQQ9) were active against Staphylococcus aureus (ATCC 29213) with MIC values of 4.88 and 2.44 μg/mL, respectively. The most potent aminated QQs (AQQ8 and AQQ9) were identified as promising lead molecules to further explore their mode of action. The selected QQs (AQQ8 and AQQ9) were further evaluated in vitro to assess their potential antimicrobial activity against each of 20 clinically obtained methicillin-resistant S. aureus isolates, antibiofilm activity, and bactericidal activity using time-kill curve assay. We found that the molecules prevented adhesion of over 50% of the cells in the biofilm. Molecular docking studies were performed to predict the predominant binding mode(s) of the ligands. We believe that the molecules need further investigation, especially against infections involving biofilm-forming microbes.

The influence of gastric atrophy on Helicobacter pylori antibiotics resistance in therapy-naïve patients

BACKGROUND

Antibiotic susceptibility of Helicobacter pylori to antibiotics may vary among different niches of the stomach. The progression of chronic H. pylori gastritis to atrophy changes intragastric physiology that may influence selection of resistant strains.

AIM

To study the antibiotic resistance of H. pylori taking the severity of atrophic gastritis in antrum and corpus into account.

METHODS

Helicobacter pylori-positive patients (n = 110, m = 32, mean age 52.6 ± 13.9 years) without prior H. pylori eradication undergoing upper gastrointestinal (GI) endoscopy for dyspeptic symptoms were included in a prospective study. Patients were stratified into three groups depending on the grade of atrophy: no atrophy (OLGA Stage 0), mild atrophy (OLGA Stage I-II) and moderate/severe atrophy (OLGA Stage III-IV). Two biopsies each from the antrum and the corpus and one from the angulus were taken and assessed according to the updated Sydney system. H. pylori strains were isolated from antrum and corpus biopsies and tested for antibiotic susceptibility (AST) for amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin by the agar dilution methods. A Chi-square test of independence with a 95% confidence interval was used to detect differences in the proportion of patients with susceptible and resistant H. pylori strains.

RESULTS

Among 110 patients, primary clarithromycin resistance (R) was 30.0%, both in the antrum and corpus; metronidazole resistance accounted for 36.4 and 34.5% in the antrum and corpus; and levofloxacin was 19.1 and 22.7% in the antrum and corpus, respectively. Resistance rates to amoxicillin, tetracycline, and rifampicin were below 5%. Dual antibiotic resistance rate was 21.8%, and triple resistance rate was 9.1%. There was a significant difference in the resistance rate distribution in antrum (p < 0.0001) and corpus (p < 0.0001). With increasing severity of atrophy according to OLGA stages, there was a significant increase in clarithromycin-R and metronidazole-R.

CONCLUSION

In treatment-naïve patients, antibiotic resistance and heteroresistance were related to the severity of atrophy. The high clarithromycin resistance in atrophic gastritis suggests that H. pylori antibiotic susceptibility testing should always be performed in this condition before selecting the eradication regimen.

Myths and Misconceptions around Antibiotic Resistance: Time to Get Rid of Them

The antibiotic resistance arena is fraught with myths and misconceptions, leading to wrong strategies to combat it. It is crucial to identify them, discuss them in light of current evidence, and dispel those that are unequivocally wrong. This article proposes some concepts that may qualify as misconceptions around antibiotic resistance: the susceptible-resistant dichotomy; that incomplete antibiotic courses cause resistance; that resistance "emerges" in patients and hospitals; that antibiotics are mostly abused clinically; that resistance is higher in countries that use more antibiotics; that reducing antibiotic usage would reduce resistance; that financial incentives would "jumpstart" research and development of antibiotics; that generic and "original" antibiotics are the same; and that new anti-infective therapies are just around the corner. While some of these issues are still controversial, it is important to recognize their controversial status, instead of repeating them in specialized literature and lectures and, especially, in the planning of strategies to cope with resistance.

Epidemiologic and clinical characteristics of human bocavirus infection in children hospitalized for acute respiratory tract infection in Qingdao, China

Persistent infection and prolonged shedding of human bocavirus 1 (HBoV1) in children have been reported, and the role of HBoV1 as a sole causative pathogen in acute respiratory infection (ARI) is yet to be established. While the reported prevalence of HBoV infection varies due to different detection methods and sampling criteria, determining the viral and bacterial etiology of HBoV infection using multiplex real-time PCR is yet to be reported. Herein, we aimed to further explore the pathogenicity of HBoV in patients with ARI by screening the viral and bacterial infections in children with ARI in Qingdao and comparing the epidemiological, clinical characteristics, and etiological results. Human bocavirus was identified in 28.1% of the samples, and further sequencing analysis of the detected HBoV confirmed 96.4% as HBoV1. The rate of HBoV as a single viral infection was 75%, and the rate of coinfection with bacteria was 66.1%, suggesting the need for continued monitoring of HBoV in children with ARIs. Clinical characterization suggested that HBoV infection may affect the function of organs, such as the liver, kidney, and heart, and the blood acid–base balance. Additionally, it is essential to promote awareness about the importance of disinfection and sterilization of the hospital environment and standardizing operations. The interactions between HBoV and other pathogens remain to be investigated in further detail in the future.

Antimicrobial Resistance Development Pathways in Surface Waters and Public Health Implications

Human health is threatened by antibiotic-resistant bacteria and their related infections, which cause thousands of human deaths every year worldwide. Surface waters are vulnerable to human activities and natural processes that facilitate the emergence and spread of antibiotic-resistant bacteria in the environment. This study evaluated the pathways and drivers of antimicrobial resistance (AR) in surface waters. We analyzed antibiotic resistance healthcare-associated infection (HAI) data reported to the CDC's National Healthcare Safety Network to determine the number of antimicrobial-resistant pathogens and their isolates detected in healthcare facilities. Ten pathogens and their isolates associated with HAIs tested resistant to the selected antibiotics, indicating the role of healthcare facilities in antimicrobial resistance in the environment. The analyzed data and literature research revealed that healthcare facilities, wastewater, agricultural settings, food, and wildlife populations serve as the major vehicles for AR in surface waters. Antibiotic residues, heavy metals, natural processes, and climate change were identified as the drivers of antimicrobial resistance in the aquatic environment. Food and animal handlers have a higher risk of exposure to resistant pathogens through ingestion and direct contact compared with the general population. The AR threat to public health may grow as pathogens in aquatic systems adjust to antibiotic residues, contaminants, and climate change effects. The unnecessary use of antibiotics increases the risk of AR, and the public should be encouraged to practice antibiotic stewardship to decrease the risk.

[Practice-guided Presentation of the German S3 Guideline "Strategies to Warrant Rational In-hospital Use of Antibiotics"]

The current S3 guideline entitled "Strategies to warrant rational in-hospital use of antibiotics" summarizes evidence-based antibiotic stewardship (ABS) measures that aim to improve clinical outcomes and prevent development and spread of microbial resistance in German hospitals. Most important prerequisite for efficiency and safety of ABS programs is sufficient staffing capacity as well as reliably operating surveillance of (i) pathogens, (ii) antimicrobial resistance and (iii) consumption of antimicrobials. ABS teams require authorization by hospital institutions as units exclusively responsible for antimicrobial audits and implementation of anti-infective interventions. Clinicians should be regularly granted access to in-hospital training programs delivered by ABS experts. Finally yet importantly, the current S3 guideline also highlights future goals, e.g., the structured involvement for nurses in ABS-guided infection management or the promotion of ABS programs in the outpatient sector and in veterinary medicine.

Isolation, Identification, and Susceptibility Profile of E. coli, Salmonella, and S. aureus in Dairy Farm and Their Public Health Implication in Central Ethiopia

A cross-sectional study was conducted from November 2018 to May 2019 in Bishoftu and Dukem in central part of Ethiopia. The objectives of the present study were to isolate and identify S. aureus, E. coli, and Salmonella from dairy cattle, personnel, and equipment at farms. In addition to this, antimicrobial resistance profiles of the isolates were determined. A total of 607 samples consisting of fresh cow milk (125), fecal sample (211), nasal swab (211), pooled milkers' hand swabs (20), pooled floor swabs (20), and tank milk (20) samples were collected from 20 dairy farms, which included 211 animals. Structured questionnaire was designed and administered to dairy farm owners and dairy food consumers to assess their consumption behavior and antibiotics usage. The samples were examined for the presence of S. aureus, E. coli, and Salmonella following standard techniques and procedures outlined by the International Organization for Standardization. Subsequently, 62 (15.7%) of S. aureus were isolated from 396 of the totals analyzed samples for S. aureus. Out of the 62 isolated S. aureus, 35/211(16.7%), 19/125(15.2%), 6/20(30%), 2/20(10%), and 0/20(0%) were from nasal swabs, udder milk, bulk milk, pooled hand swab, and floor swabs, respectively. On the other hand, 30 (7.6%) of E. coli were isolated from 396 of the totals analyzed samples for E. coli. Out of the 30 isolated E. coli, 17/211(8.1%), 12/125(9.6%), 0/20(0%), 0/20(0%), and 1/20(5%) were from faeces, udder milk, bulk milk, pooled hand swab, and floor swabs, respectively. In line with this, 13 (4.8%) of Salmonella were isolated from 271 of the totals analyzed samples for Salmonella. Out of the 13 isolated Salmonella, 10/211(4.7%), 2/20(10%), 0/20(0%), and 1/20(5%) were from faeces, bulk milk, pooled hand swab, and floor swabs, respectively. Subsequently, 62 of S. aureus, 30 of E. coli, and 13 of Salmonella isolates were subjected to antimicrobial susceptibility testing, and all isolates were resistant to at least one or more antimicrobials tested. Penicillin, methicillin, and trimethoprim/sulfamethoxazole are drugs to which a large proportion of isolated S. aureus were highly resistant, which range from 90% to 100%. From 30 tested E. coli, they showed (83%) resistance to Tetracycline and 80% to Vancomycin. The resistance level of 13 isolated Salmonella was 69% to Nalidixic acid and 54% to Vancomycin. Multiple drug resistance was detected in high (98.4%) for S. aureus, (56.7%) for E. coli, and (53.9%) for Salmonella. High proportion of multiple drug resistant in the dairy farm alerts concern for animal and public health as these drugs are used widely for treatment and prophylaxis in animals and humans.

Prevalence and antimicrobial susceptibility pattern of urinary tract infection among pregnant women attending Hargeisa Group Hospital, Hargeisa, Somaliland

The aim of this study was to determine the prevalence, antimicrobial susceptibility pattern and associated factors of urinary tract infection (UTI) among pregnant women attending Hargeisa Group Hospital (HGH), Hargeisa, Somaliland. A cross-sectional study was conducted at HGH, Hargeisa, Somaliland and participants were selected by systematic random sampling technique. Clean catch midstream urine samples were collected from 422 participants and cultured and antimicrobial susceptibility pattern was determined for the isolates. Univariable and multivariable logistic regression analyses were utilized to identify the independent risk factors for UTI. The prevalence of UTI was 16.4% (95% CI 13.3-19.9). The predominant bacteria isolate was E. coli (43.5%) followed by Coagulase negative staphylococcus (CoNS) 11(16%), S. aureus 9(13%), K. pneumonia 6(8.7%), Pseudomonas aeruginosa 5(7.2%), Proteus mirabilis 4(5.8%), Citrobacter spp 3(4.4%) and M. morganii 1(1.5%) Gram negative bacilli were resistant to ampicillin (96%) and tetracycline (71.4%) and Gram-positive cocci were also resistant to ampicillin (90%), tetracycline (55%). Multidrug resistance was observed in 85.5% of bacterial isolated. No formal education participants, previous history of catheterization and previous history of UTI had 3.18, 3.22 and 3.73 times respectively more likely to develop UTI than their counterparts. Culture and susceptibility test is vital for appropriate management of UTI in the study area.

Analysis of Antimicrobial Use and the Presence of Antimicrobial-Resistant Bacteria on Austrian Dairy Farms-A Pilot Study

The assumed link between high levels of antimicrobial use on farms and selection for antimicrobial-resistant (AMR) bacteria on that farm remains difficult to prove. In the pilot study presented here, we analysed total antimicrobial use on 50 dairy farms in Austria and also collected environmental samples to ascertain whether specific AMR bacteria were present. Antimicrobial use (AMU) analysis was based on electronic veterinary treatment records over a one-year period. Faecal samples for the assessment of extended-spectrum beta-lactamase (ESBL)-producing E. coli were collected from cowsheds, calf pens, and youngstock housing areas, as well as dust samples from barns, to isolate methicillin-resistant Staphylococcus aureus (MRSA). Bacteriological cultures were carried out on selective agar. Farms were split into groups of 25 of the highest antimicrobial users and 25 of the lowest users. Overall, samples from 13/50 (26.0%) farms were found to be positive for the presence of ESBL-producing E. coli. Of these, eight farms were in the low user group and five were in the high user group. Only one farm was confirmed to harbour MRSA. Statistical analyses demonstrated that there was no significant difference in this study population between high or low antimicrobial use with respect to the presence of ESBL-producing E. coli on farms (p = 0.33). In conclusion, the presence of specific AMR bacteria on farms in this study population was not found to have a statistically proven relationship with their level of antimicrobial use.

Perceptions of primary health care physicians about the prescription of antibiotics in Saudi Arabia: Based on the model of Theory of planned behaviour

Introduction

Knowledge of different factors that influence physician decision-making in general practice for prescribing antibiotics is vital for successfully implementing antimicrobial stewardship interventions. The Theory of planned behaviour (TPB) is an established model that describes how cognitions drive human behaviour.

Objectives

The present study was performed to identify the socio-cultural and behavioural determinants that affect antibiotics prescription behaviour among primary care physicians and estimate the awareness about antibiotic resistance of public health importance.

Methodology

The questionnaire was divided into three sections: Section-I, which contained demographic content. Section-II contained 21 question items measuring attitudes, subjective norms, perceived behavioural control, and behavioural intentions of the prescribers. Section III had 12 questions related to knowledge about antibiotic resistance. As determined by Cronbach's α for each set of measured constructs of questionnaire scale, the internal consistency was good (α ≥ 0.7). The participants' socio-cultural and behavioural determinants were graded in 3 categories depending upon the mean score, while frequencies were used to estimate antibiotic resistance awareness. The data was analyzed by calculating the one-way ANOVA and by post-hoc Tukey-Kramer HSD multiple comparison test.

Results

Four hundred thirty-four primary health care physicians responded to the questionnaire, and data was statistically investigated. Participants' knowledge of antibiotic-resistant bacteria was poor with greater behavioural intentions to prescribe antibiotics, but a positive attitude and acceptable perceived social pressure towards antibiotics.

Conclusion

Our study showed that awareness towards antibiotic-resistant bacteria among primary care physicians of Saudi Arabia stands insufficient but favourable attitude and satisfactory social pressure towards antibiotics with greater behavioural intentions to prescribe antibiotics. The continued medical education (CME) and frequent training interventions can increase these parameters of rational prescribing practice for antibiotics.

Antibiotic Stewardship und chronische Lungenerkrankungen

Hintergrund

Ziel dieser Arbeit

Material und Methoden

Ergebnisse und Diskussion

A systems thinking approach for antimicrobial stewardship in primary care

INTRODUCTION

The establishment of antimicrobial stewardship (AMS) in primary care is central to substantially reduce the antimicrobial use and the associated risk of resistance. This perspective piece highlights the importance of systems thinking to set up and facilitate AMS programs in primary care.

AREAS COVERED

The challenges that primary care faces to incorporate AMS programmes is multifactorial: an implementation framework, relevant resources, team composition, and system structures remain under-researched, and these issues are often overlooked and/or neglected in most parts of the world. Progress in the field remains slow in developed countries but potentially limited in low- and middle-income countries.

EXPERT OPINION

The key AMS strategies to optimize antimicrobial use in primary care are increasingly known; however, health system components that impact effective implementation of AMS programs remain unclear. We highlight the importance of systems thinking to identify and understand the resource arrangements, system structures, dynamic system behaviors, and intra- and interprofessional connections to optimally design and implement AMS programs in primary care. An AMS systems thinking systemigram (i.e. a visual representation of overall architecture of a system) could be a useful tool to foster AMS implementation in primary care.

Viral burden and diversity in acute respiratory tract infections in hospitalized children in wet and dry zones of Sri Lanka

The present study was done to identify the viral diversity, seasonality and burden associated with childhood acute respiratory tract infection (ARTI) in Sri Lanka. Nasopharyngeal aspirates (NPA) of hospitalized children (1 month-5 years) with ARTI were collected in 2 centers (wet and dry zones) from March 2013 to August 2014. Respiratory viral antigen detection by immunofluorescence assay (IFA) was used to identify the infecting viruses. IFA negative 100 NPA samples were tested for human metapeumovirus (hMPV), human bocavirus and corona viruses by polymerase chain reaction. Of the 443 and 418 NPAs, 37.2% and 39.4% were positive for any of the 8 different respiratory viruses tested from two centers studied. Viral co-infection was detected with respiratory syncytial virus (RSV) in both centers. Peak viral detection was noted in the wet zone from May-July 2013 and 2014 and in the dry zone from December-January 2014 suggesting a local seasonality for viral ARTI. RSV showed a clear seasonality with a direct correlation of monthly RSV infections with rainy days in the wet zone and an inverse correlation with temperature in both centers. The case fatality rate was 2.7% for RSV associated ARTI. The overall disability adjusted life years was 335.9 and for RSV associated ARTI it was 241.8. RSV was the commonly detected respiratory virus with an annual seasonality and distribution in rainy seasons in the dry and wet zones of Sri Lanka. Identifying the virus and seasonality will contribute to employ preventive measures and reduce the empirical use of antibiotics in resource limited settings.

Hyaluronic Acid Derivative Molecular Weight-Dependent Synthesis and Antimicrobial Effect of Hybrid Silver Nanoparticles

Silver nanoparticles (Ag NPs) appeared as promising antimicrobial candidates to face the development of antibiotic resistance. Although reported as toxic towards mammalian cells, their combination with biomolecules have shown reduced toxicity, while maintaining the antimicrobial function. Herein, hyaluronic acid (HA) with low (40 kDa), medium (200 and 600 kDa) and high (2 MDa) molecular weight (Mw) was modified with adipic acid dihydrazide (ADH) and used as reducing and capping agents to synthesise antimicrobial hybrid Ag NPs. The Mw of the polymer played a crucial role in the morphology, size and antibacterial activity of the Ag NPs. The 600 and 200 kDa HA-ADH-Ag NPs were able to reduce the Escherichia coli and Staphylococcus aureus concentration by more than 3 logs, while the 40 kDa NPs reached ~2 logs reduction. The 2 MDa HA-ADH failed to form homogenous NPs with strong bactericidal activity. A mechanistic study of the interaction with a model bacterial membrane using Langmuir isotherms confirmed the greater interaction between bacteria and higher Mw polymers and the effect of the NP’s morphology. The nanocomposites low toxicity to human skin cells was demonstrated in vitro, showing more than 90% cell viability after incubation with the NPs.

Global antibiotic consumption and usage in humans, 2000-18: a spatial modelling study

BACKGROUND

Antimicrobial resistance (AMR) is a serious threat to global public health. WHO emphasises the need for countries to monitor antibiotic consumption to combat AMR. Many low-income and middle-income countries (LMICs) lack surveillance capacity; we aimed to use multiple data sources and statistical models to estimate global antibiotic consumption.

METHODS

In this spatial modelling study, we used individual-level data from household surveys to inform a Bayesian geostatistical model of antibiotic usage in children (aged <5 years) with lower respiratory tract infections in LMICs. Antibiotic consumption data were obtained from multiple sources, including IQVIA, WHO, and the European Surveillance of Antimicrobial Consumption Network (ESAC-Net). The estimates of the antibiotic usage model were used alongside sociodemographic and health covariates to inform a model of total antibiotic consumption in LMICs. This was combined with a single model of antibiotic consumption in high-income countries to produce estimates of antibiotic consumption covering 204 countries and 19 years.

FINDINGS

We analysed 209 surveys done between 2000 and 2018, covering 284 045 children with lower respiratory tract infections. We identified large national and subnational variations of antibiotic usage in LMICs, with the lowest levels estimated in sub-Saharan Africa and the highest in eastern Europe and central Asia. We estimated a global antibiotic consumption rate of 14·3 (95% uncertainty interval 13·2-15·6) defined daily doses (DDD) per 1000 population per day in 2018 (40·2 [37·2-43·7] billion DDD), an increase of 46% from 9·8 (9·2-10·5) DDD per 1000 per day in 2000. We identified large spatial disparities, with antibiotic consumption rates varying from 5·0 (4·8-5·3) DDD per 1000 per day in the Philippines to 45·9 DDD per 1000 per day in Greece in 2018. Additionally, we present trends in consumption of different classes of antibiotics for selected Global Burden of Disease study regions using the IQVIA, WHO, and ESAC-net input data. We identified large increases in the consumption of fluoroquinolones and third-generation cephalosporins in North Africa and Middle East, and south Asia.

INTERPRETATION

To our knowledge, this is the first study that incorporates antibiotic usage and consumption data and uses geostatistical modelling techniques to estimate antibiotic consumption for 204 countries from 2000 to 2018. Our analysis identifies both high rates of antibiotic consumption and a lack of access to antibiotics, providing a benchmark for future interventions.

FUNDING

Fleming Fund, UK Department of Health and Social Care; Wellcome Trust; and Bill & Melinda Gates Foundation.

Pneumococcal Extracellular Serine Proteases: Molecular Analysis and Impact on Colonization and Disease

The pathobiont Streptococcus pneumoniae causes life-threatening diseases, including pneumonia, sepsis, meningitis, or non-invasive infections such as otitis media. Serine proteases are enzymes that have been emerged during evolution as one of the most abundant and functionally diverse group of proteins in eukaryotic and prokaryotic organisms. S. pneumoniae expresses up to four extracellular serine proteases belonging to the category of trypsin-like or subtilisin-like family proteins: HtrA, SFP, PrtA, and CbpG. These serine proteases have recently received increasing attention because of their immunogenicity and pivotal role in the interaction with host proteins. This review is summarizing and focusing on the molecular and functional analysis of pneumococcal serine proteases, thereby discussing their contribution to pathogenesis.

Association of pneumococcal serotype with susceptibility to antimicrobial drugs: a systematic review and meta-analysis

BACKGROUND

Pneumococcal serotypes differ in antimicrobial susceptibility. However, patterns and causes of this variation are not comprehensively understood.

METHODS

We undertook a systematic review of epidemiologic studies of pneumococci isolated from carriage or invasive disease among children globally from 2000-2019. We evaluated associations of each serotype with nonsusceptibility to penicillin, macrolides, and trimethoprim/sulfamethoxazole. We evaluated differences in the prevalence of nonsusceptibility to major antibiotic classes across serotypes using random effects meta-regression models, and assessed changes in prevalence of nonsusceptibility after implementation of pneumococcal conjugate vaccines (PCVs). We also evaluated associations between biological characteristics of serotypes and their likelihood of nonsusceptibility to each drug.

RESULTS

We included data from 129 studies representing 32,187 isolates across 52 countries. Within serotypes, the proportion of nonsusceptible isolates varied geographically and over time, in settings using and those not using PCVs. Factors predicting enhanced fitness of serotypes in colonization as well as enhanced pathogenicity were each associated with higher likelihood of nonsusceptibility to penicillin, macrolides, and trimethoprim/sulfamethoxazole. Increases in prevalence of nonsusceptibility following PCV implementation were evident among non-PCV serotypes including 6A, 6C, 15A, 15B/C, 19A, and 35B; however, this pattern was not universally evident among non-PCV serotypes. Post-vaccination increases in nonsusceptibility for serotypes 6A and 19A were attenuated in settings that implemented PCV13.

CONCLUSIONS

In pneumococci, nonsusceptibility to penicillin, macrolides, and trimethoprim/sulfamethoxazole is associated with more frequent opportunities for antibiotic exposure during both prolonged carriage episodes and when serotypes cause disease. These findings suggest multiple pathways leading to resistance selection in pneumococci.

BactoSpin: Novel Technology for Rapid Bacteria Detection and Antibiotic Susceptibility Testing

Inappropriate use of antibiotics is one of the leading causes of the increasing numbers of resistant bacteria strains, resulting in 700,000 deaths worldwide each year. Reducing unnecessary use of antibiotics and choosing the most effective antibiotics instead of broad-spectrum drugs will slow the arms race between germs and humans. Urinary tract infections (UTIs) are among the most common bacterial infections. Currently, accurate diagnosis of UTI requires approximately 48 h from the time of urine sample collection until antibiotic susceptibility test (AST) results. This work presents a rapid bacterial detection device that integrates a centrifuge, microscope, and incubator. Two disposable microfluidic chips were developed. The first chip was designed for bacteria concentration, detection, and medium exchange. A second multi-channel chip was developed for AST. This chip contains superhydrophobic and hydrophilic coatings to ensure liquid separation between the channels without the need for valves. The designed chips supported the detection of E. coli at a concentration as low as 5 × 10³ cells/mL within 5 min and AST in under 2 h. AST was also successfully performed with Klebsiella pneumonia isolated from a human urine sample. In addition, machine-learning-based image recognition was shown to reduce the required time for AST and to provide results within 1 h for E. coli cells. Thus, the BactoSpin device can serve as an efficient and rapid platform for UTI diagnostics and AST.

Desirability of Outcome Ranking for the Management of Antimicrobial Therapy (DOOR MAT): A Framework for Assessing Antibiotic Selection Strategies in the Presence of Drug Resistance

The complexities of antibiotic resistance mean that successful stewardship must consider both the effectiveness of a given antibiotic and the spectrum of that therapy to minimize imposing further selective pressure. To meet this challenge, we propose the Desirability of Outcome Ranking approach for the Management of Antimicrobial Therapy (DOOR MAT), a flexible quantitative framework that evaluates the desirability of antibiotic selection. Herein, we describe the steps required to implement DOOR MAT and present examples to illustrate how the desirability of treatment selection can be evaluated using resistance information. While treatments and the scoring of treatment selections must be adapted to specific clinical settings, the principle of DOOR MAT remains constant: The most desirable antibiotic choice effectively treats the patient while exerting minimal pressure on future resistance.

Antimicrobial stewardship in rural and remote primary health care: a narrative review

BACKGROUND

Antimicrobial resistance is an emerging problem worldwide and poses a significant threat to human health. Antimicrobial stewardship programmes are being implemented in health systems globally, primarily in hospitals, to address the growing threat of antimicrobial resistance. Despite the significance of primary health care services in providing health care to communities, antimicrobial stewardship programmes are not well established in this sector, especially in rural and remote settings. This narrative review aims to identify in rural and remote primary health care settings the (1) correlation of antimicrobial resistance with antibiotic prescribing and volume of antibiotic use, (2) appropriateness of antimicrobial prescribing, (3) risk factors associated with inappropriate use/prescribing of antibiotics, and (4) effective antimicrobial stewardship strategies.

METHODS

The international literature was searched for English only articles between 2000 and 2020 using specified keywords. Seven electronic databases were searched: Scopus, Cochrane, Embase, CINAHL, PubMed, Ovid Medline and Ovid Emcare. Publication screening and analysis were conducted using Joanna Briggs Institute systematic review tools.

RESULTS

Fifty-one eligible articles were identified. Inappropriate and excessive antimicrobial prescribing and use directly led to increases in antimicrobial resistance. Increasing rurality of practice is associated with disproportionally higher rates of inappropriate prescribing compared to those in metropolitan areas. Physician knowledge, attitude and behaviour play important roles in mediating antimicrobial prescribing, with strong intrinsic and extrinsic influences including patient factors. Antimicrobial stewardship strategies in rural and remote primary health care settings focus on health care provider and patient education, clinician support systems, utility of antimicrobial resistance surveillance, and policy changes. Results of these interventions were generally positive with decreased antimicrobial resistance rates and improved appropriateness of antimicrobial prescribing.

CONCLUSIONS

Inappropriate prescribing and excessive use of antimicrobials are an important contributor to the increasing resistance towards antimicrobial agents particularly in rural and remote primary health care. Antimicrobial stewardship programmes in the form of education, clinical support, surveillance, and policies have been mostly successful in reducing prescribing rates and inappropriate prescriptions. The narrative review highlighted the need for longer interventions to assess changes in antimicrobial resistance rates. The review also identified a lack of differentiation between rural and remote contexts and Indigenous health was inadequately addressed. Future research should have a greater focus on effective interventional components and patient perspectives.

The role of antimicrobial stewardship in preventing KPC-producing Klebsiella pneumoniae

Antimicrobial stewardship programmes are widely considered to be a core component of the response to the antimicrobial resistance threat. However, a positive impact of these interventions in terms of microbiological outcomes remains difficult to demonstrate, especially when focusing on specific resistant phenotypes. The first part of this review aims to explore the complex relationship between antibiotic exposure and resistance development in KPC-producing Klebsiella pneumoniae. In the second part we aim to summarize published examples of antimicrobial stewardship interventions intended to impact on the epidemiology of KPC-producing K. pneumoniae. For this purpose, a literature search was performed and seven studies were included in the review. Both restrictive and non-restrictive interventions were associated with an overall reduction in antibiotic consumption, and a decrease in carbapenem resistance rates was observed in five studies. The overall quality of the evidence was low, mainly due to the poor reporting of microbiological outcomes, lack of a control group and suboptimal study design. Although the link between antibiotic use and resistance development is supported by strong evidence, demonstrating the impact of antimicrobial stewardship interventions on microbiological outcomes remains difficult. Studies with adequate design and appropriate outcome measures are needed to further promote antimicrobial stewardship and elucidate which interventions are more successful for controlling the spread of KPC-producing K. pneumoniae.

Correlation between Antibiotic Consumption and Resistance of Invasive Streptococcus pneumoniae

There is a lack of long-term studies that correlate different metrics of antibiotic consumption and resistance of invasive S. pneumoniae. The present study aims to investigate the correlation between national outpatients total antibiotic, penicillin and broad spectrum penicillins consumption expressed in daily doses per 1000 inhabitants per day (DID) with the ATC/DDDs, WHO version of 2019 (new version) and 2018 (old version), number of prescriptions per 1000 inhabitants per year (RxIDs) and number of packages per 1000 inhabitant per day (PIDs) with the resistance of invasive S. pneumoniae in Slovenia in the period from 2000 to 2018. The prevalence of penicillin resistance of invasive S. pneumoniae decreased by 47.13%, from 19.1% to 10.1%. Decline of resistance showed the highest correlation (R = 0.86) between RxIDs followed by PID (R = 0.85) and resistance of S. pneumoniae. Higher correlation between total use of antibiotics expressed in DID WHO version 2019 (R = 0.80) than for WHO version 2018 (R = 0.78) was found. Very high (R = 0.84) correlation between use of β-lactams expressed in PID, and RxIDs (R = 0.82) and reasonable (R = 0.59) correlation expressed in DIDs version 2019 was shown as well. The consumption of broad -spectrum penicillins (J01CA and J01CR02) expressed in PID (R = 0.72) and RxIDs (0.57) correlated significantly with the resistance of S. pneumoniae as well. A new finding of this study is that RxIDs correlated better with the resistance of S. pneumoniae than total consumption of antibiotics expressed in DID and significant correlations exist between use of broad-spectrum penicillins expressed in PID and RxIDs.

Factors Related to Antibiotic Supply without a Prescription for Common Infections: A Cross-Sectional National Survey in Sri Lanka

Inappropriate antibiotic use is a problem in Sri Lanka. We investigated pharmacy staff’s attitudes towards antibiotic supply for common infections in Sri Lanka. A self-reported cross-sectional survey was conducted among a random sample (n = 369) of pharmacies. We assessed staff’s beliefs and attitudes to antibiotic supplying for common infections (common cold and cough, sore throat, diarrhoea, wound and urinary tract infections (UTI)). Pharmacists (n = 210; 79%) and pharmacy assistants (n = 55: 21%) responded. About 30% (80/265) had supplied antibiotics without a prescription for common infections, including common cold (15.8%), sore throat (13.6%) and diarrhoea (10.2%). Overall, pharmacists were less likely to supply than non-pharmacists. Pharmacy staff with more positive beliefs about their professional competency to supply and monitor antibiotic use were more likely to supply antibiotics without a prescription for common cold (Adj.OR = 1.08; 95% CI: 1.01–1.15; p = 0.032), wound infections (Adj. OR = 1.06; 95% CI: 1.00–1.13; p = 0.059), and UTI (Adj.OR = 1.07; 95% CI: 0.99–1.15; p = 0.097). Pharmacy staff who believed in the effectiveness of antibiotics against common infections were more likely to supply antibiotics for common infections. Supply of antibiotics without a prescription was associated with staff’s beliefs about antibiotics’ effectiveness and their professional competency. Our findings could be used to strengthen regulatory strategies to improve practice.

Arriving at no: Patient pressure to prescribe antibiotics and physicians' responses

While the vast majority of Acute Respiratory Infections (ARIs) are viral, between a quarter and a third of adults presenting with ARIs are given an antibiotic, making antibiotic prescribing for ARIs a major contributor to the inappropriate prescribing problem. We argue that inappropriate prescribing persists because of the interplay between physicians and patients in the medical visit. Relying on a convenience sample of 68 video recordings of primary care medical visits drawn from corpora collected in 2003-2004 and 2015-2016 in the US, we show that although few patients are "demanding" or "requesting" antibiotics, many convey subtle forms of pressure through priming physicians for a bacterial diagnosis in their problem presentations; nudging towards a bacterial diagnosis during information gathering; and resisting non-antibiotic recommendations during the counseling phase. We find that patient priming, nudging, and resisting are effective strategies to influence clinical prescribing behavior. However, we also identify two ways that physicians can counter patient pressure by working to manage patient expectations through foreshadowing a non-antibiotic outcome and using persuasion when confronted with resistance. These, we show, are effective means of countering patient pressure. We argue for the dual importance of how physicians communicate and when they communicate.

Biofabricated silver nanoparticles exhibit broad-spectrum antibiofilm and antiquorum sensing activity against Gram-negative bacteria

The emergence and spread of antimicrobial resistance (AMR) among bacterial pathogens have created a global threat to human health and the environment. Targeting the quorum sensing (QS) linked virulent traits of bacteria is considered to be a novel approach for addressing the problem of AMR. In this study, green synthesized silver nanoparticles (AgNPs-MK) were evaluated for the inhibition of the formation of biofilms and quorum sensing controlled virulence factors against three Gram negative bacteria. Remarkable inhibition (>80%) of QS-mediated violacein production was recorded in C. violaceum 12472. Up to 90% inhibition of the QS-mediated virulent traits of S. marcescens MTCC 97 was observed. The virulence factors of P. aeruginosa PAO1 also decreased in a dose dependent manner in the presence of AgNPs-MK. Moreover, the development of biofilms of C. violaceum 12472, S. marcescens MTCC 97, and P. aeruginosa PAO1 was reduced by 87.39, 81.54, and 71.34%, respectively. Biofilms on glass surfaces were remarkably reduced, with less aggregation of bacterial cells and the reduced formation of extra polymeric substances. The findings clearly show the efficacy of AgNPs-MK against the development of biofilms and the QS mediated virulent traits of Gram negative bacterial pathogens. AgNPs-MK may be further exploited for the development of alternative antimicrobial agents after careful scrutiny in animal models for the management of bacterial infections, especially for topical applications.

Rising Pneumococcal Antibiotic Resistance in the Post-13-Valent Pneumococcal Conjugate Vaccine Era in Pediatric Isolates From a Primary Care Setting

BACKGROUND

Antibiotic-resistant Streptococcus pneumoniae strains may cause infections that fail to respond to antimicrobial therapy. Results reported from hospitalized patients with invasive, bacteremic infections may not be the same as those observed in a primary care setting where young children receive care for noninvasive infections. Young children experience the highest burden of pneumococcal disease. The aim of this study was to determine the antibiotic susceptibility of S. pneumoniae strains isolated from children in a primary care setting in the post-13-valent pneumococcal conjugate vaccine (PCV13) era.

METHODS

This was a prospective collection of 1201 isolates of S. pneumoniae from 2006 through 2016 in a primary care setting. Antibiotic susceptibility testing to 16 different antibiotics of 10 classes was performed. Participants were children aged 6-36 months. Nasopharyngeal swabs were obtained from patients during acute otitis media (AOM) visits and routine healthy visits. Middle ear fluid was obtained by tympanocentesis.

RESULTS

After introduction of PCV13, antibiotic susceptibility of pneumococci, especially to penicillin, initially improved largely due to disappearance of serotype 19A, included in PCV13. However, beginning in 2013, antibiotic susceptibility among pneumococcal strains began decreasing due to new serotypes not included in PCV13. In addition to reduced susceptibility to penicillin, the most recent isolates show reduced susceptibility to third-generation cephalosporins, fluoroquinolones, and carbapenems, antibiotics commonly used to treat life-threatening, invasive pneumococcal diseases.

CONCLUSIONS

In recent years, pneumococcal nasopharyngeal and AOM isolates from children exhibit reduced susceptibility to penicillin, third-generation cephalosporin, fluoroquinolone, and carbapenem antibiotics. The new strains have a different profile of resistance compared to the pre-PCV13 era.