The impact of antibiotic use on transmission of resistant bacteria in hospitals: Insights from an agent-based model

Nanoemulsions of essential oils against multi-resistant microorganisms: An integrative review

Microbial resistance to drugs continues to be a global public health issue that demands substantial investment in research and development of new antimicrobial agents. Essential oils (EO) have demonstrated satisfactory and safe antimicrobial action, being used in pharmaceutical, cosmetic, and food formulations. In order to improve solubility, availability, and biological action, EO have been converted into nanoemulsions (NE). This review identified scientific evidence corroborating the antimicrobial action of nanoemulsions of essential oils (NEEO) against antibiotic-resistant pathogens. Using integrative review methodology, eleven scientific articles evaluating the antibacterial or antifungal assessment of NEEO were selected. The synthesis of evidence indicates that NEEO are effective in combating multidrug-resistant microorganisms and in the formation of their biofilms. Factors such as NE droplet size, chemical composition of essential oils, and the association of NE with antibiotics are discussed. Furthermore, NEEO showed satisfactory results in vitro and in vivo evaluations against resistant clinical isolates, making them promising for the development of new antimicrobial and antivirulence drugs.

Healthcare as a driver, reservoir and amplifier of antimicrobial resistance: opportunities for interventions

Antimicrobial resistance (AMR) is a global health challenge that threatens humans, animals and the environment. Evidence is emerging for a role of healthcare infrastructure, environments and patient pathways in promoting and maintaining AMR via direct and indirect mechanisms. Advances in vaccination and monoclonal antibody therapies together with integrated surveillance, rapid diagnostics, targeted antimicrobial therapy and infection control measures offer opportunities to address healthcare-associated AMR risks more effectively. Additionally, innovations in artificial intelligence, data linkage and intelligent systems can be used to better predict and reduce AMR and improve healthcare resilience. In this Review, we examine the mechanisms by which healthcare functions as a driver, reservoir and amplifier of AMR, contextualized within a One Health framework. We also explore the opportunities and innovative solutions that can be used to combat AMR throughout the patient journey. We provide a perspective on the current evidence for the effectiveness of interventions designed to mitigate healthcare-associated AMR and promote healthcare resilience within high-income and resource-limited settings, as well as the challenges associated with their implementation.

Using contact network dynamics to implement efficient interventions against pathogen spread in hospital settings: A modelling study

BACKGROUND

Long-term care facilities (LTCFs) are hotspots for pathogen transmission. Infection control interventions are essential, but the high density and heterogeneity of interindividual contacts within LTCF may hinder their efficacy. Here, we explore how the patient-staff contact structure may inform effective intervention implementation.

METHODS AND FINDINGS

Using an individual-based model (IBM), we reproduced methicillin-resistant Staphylococcus aureus colonisation transmission dynamics over a detailed contact network recorded within a French LTCF of 327 patients and 263 staff over 3 months. Simulated baseline cumulative colonisation incidence was 21 patients (prediction interval: 11, 31) and 35 staff (prediction interval: 19, 54). We examined the potential impact of 3 types of interventions against transmission (reallocation reducing the number of unique contacts per staff, reinforced contact precautions, and hypothetical vaccination protecting against acquisition), targeted towards specific populations. All 3 interventions were effective when applied to all nurses or healthcare assistants (median reduction in MRSA colonisation incidence up to 35%), but the benefit did not exceed 8% when targeting any other single staff category. We identified "supercontactor" individuals with most contacts ("frequency-based," overrepresented among nurses, porters, and rehabilitation staff) or with the longest cumulative time spent in contact ("duration-based," overrepresented among healthcare assistants and patients in elderly care or persistent vegetative state (PVS)). Targeting supercontactors enhanced interventions against pathogen spread in the LTCF. With contact precautions, targeting frequency-based staff supercontactors led to the highest incidence reduction (20%, 95% CI: 19, 21). Vaccinating a mix of frequency- and duration-based staff supercontactors led to a higher reduction (23%, 95% CI: 22, 24) than all other approaches. Although based on data from a single LTCF, when varying epidemiological parameters to extend to other pathogens, our results suggest that targeting supercontactors is always the most effective strategy, indicating this approach could be applied to prevent transmission of other nosocomial pathogens.

CONCLUSIONS

By characterising the contact structure in hospital settings and identifying the categories of staff and patients more likely to be supercontactors, with either more or longer contacts than others, interventions against nosocomial spread could be more effective. We find that the most efficient implementation strategy depends on the intervention (reallocation, contact precautions, vaccination) and target population (staff, patients, supercontactors). Importantly, both staff and patients may be supercontactors, highlighting the importance of including patients in measures to prevent pathogen transmission in LTCF.

Impact of withholding early antibiotic therapy in nonseptic surgical patients with suspected nosocomial infection: a retrospective cohort analysis

BACKGROUND

Systemic inflammatory responses mimicking infectious complications are often present in surgical patients.

METHODS

The objective was to assess the association between withholding early antimicrobial therapy while investigating alternative diagnoses and worse outcomes in nonseptic patients with suspected nosocomial infection in a retrospective cohort of critically ill surgical patients. The initiation of antibiotic therapy within 24 h of the suspicion of infection was defined as the Early Empirical Antibiotic strategy (EEA) group and the initiation after 24 h of suspicion or not prescribed was defined as the Conservative Antibiotic strategy (CA) group. Primary outcome was composite: death, sepsis, or septic shock within 14 days. Main exclusion criteria were sepsis or an evident source of infection at inclusion.

RESULTS

Three hundred and forty patients were eligible for inclusion (74% trauma patients). Age, sex, reason for hospital admission, SAPS3 score, SOFA score, and use of vasopressors or mechanical ventilation were not different between the groups. Within 14 days of inclusion, 100% (130/130) of EEA patients received antibiotics compared to 57% (120/210) of CA patients. After adjusting for confounding variables, there was no association between primary outcome and the groups. In a post hoc subgroup analysis including only patients with a posteriori confirmed infection (by microbiological cultures), delay in initiation of adequate antimicrobial therapy was independently associated with the primary outcome (Odds Ratio = 1.19 per day of delay; 95% CI 1.05-1.37).

CONCLUSIONS

Withholding early empiric antibiotic therapy was not associated with progression of organ dysfunction within 14 days in nonseptic surgical patients with suspected nosocomial infection without an obvious source.

An agent-based model on antimicrobial de-escalation in intensive care units: Implications on clinical trial design

Antimicrobial de-escalation refers to reducing the spectrum of antibiotics used in treating bacterial infections. This strategy is widely recommended in many antimicrobial stewardship programs and is believed to reduce patients' exposure to broad-spectrum antibiotics and prevent resistance. However, the ecological benefits of de-escalation have not been universally observed in clinical studies. This paper conducts computer simulations to assess the ecological effects of de-escalation on the resistance prevalence of Pseudomonas aeruginosa-a frequent pathogen causing nosocomial infections. Synthetic data produced by the models are then used to estimate the sample size and study period needed to observe the predicted effects in clinical trials. Our results show that de-escalation can reduce colonization and infections caused by bacterial strains resistant to the empiric antibiotic, limit the use of broad-spectrum antibiotics, and avoid inappropriate empiric therapies. Further, we show that de-escalation could reduce the overall super-infection incidence, and this benefit becomes more evident under good compliance with hand hygiene protocols among health care workers. Finally, we find that any clinical study aiming to observe the essential effects of de-escalation should involve at least ten arms and last for four years-a size never attained in prior studies. This study explains the controversial findings of de-escalation in previous clinical studies and illustrates how mathematical models can inform outcome expectations and guide the design of clinical studies.

Characterization of the resistome and predominant genetic lineages of Gram-positive bacteria causing keratitis

Bacterial keratitis is a vision-threatening infection mainly caused by Gram-positive bacteria (GPB). Antimicrobial therapy is commonly empirical using broad-spectrum agents with efficacy increasingly compromised by the emergence of antimicrobial resistance. We used a combination of phenotypic tests and genome sequencing to identify the predominant lineages of GPB causing keratitis and to characterize their antimicrobial resistance patterns. A total of 161 isolates, including Staphylococcus aureus (n = 86), coagulase-negative staphylococci (CoNS; n = 34), Streptococcus spp. (n = 34), and Enterococcus faecalis (n = 7), were included. The population of S. aureus isolates consisted mainly of clonal complex 5 (CC5) (30.2%). Similarly, the population of Staphylococcus epidermidis was homogenous with most of them belonging to CC2 (78.3%). Conversely, the genetic population of Streptococcus pneumoniae was highly diverse. Resistance to first-line antibiotics was common among staphylococci, especially among CC5 S. aureus. Methicillin-resistant S. aureus was commonly resistant to fluoroquinolones and azithromycin (78.6%) and tobramycin (57%). One-third of the CoNS were resistant to fluoroquinolones and 53% to azithromycin. Macrolide resistance was commonly caused by erm genes in S. aureus, mphC and msrA in CoNS, and mefA and msr(D) in streptococci. Aminoglycoside resistance in staphylococci was mainly associated with genes commonly found in mobile genetic elements and that encode for nucleotidyltransferases like ant(4')-Ib and ant(9)-Ia. Fluroquinolone-resistant staphylococci carried from 1 to 4 quinolone resistance-determining region mutations, mainly in the gyrA and parC genes. We found that GPB causing keratitis are associated with strains commonly resistant to first-line topical therapies, especially staphylococcal isolates that are frequently multidrug-resistant and associated with major hospital-adapted epidemic lineages.

Review of antibiotic-resistant bacteria and antibiotic resistance genes within the one health framework

Background: The interdisciplinary One Health (OH) approach recognizes that human, animal, and environmental health are all interconnected. Its ultimate goal is to promote optimal health for all through the exploration of these relationships. Antibiotic resistance (AR) is a public health challenge that has been primarily addressed within the context of human health and clinical settings. However, it has become increasingly evident that antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) that confer resistance are transmitted and circulated within humans, animals, and the environment. Therefore, to effectively address this issue, antibiotic resistance must also be considered an environmental and livestock/wildlife problem. Objective: This review was carried out to provide a broad overview of the existence of ARB and ARGs in One Health settings. Methods: Relevant studies that placed emphasis on ARB and ARGs were reviewed and key findings were accessed that illustrate the importance of One Health as a measure to tackle growing public and environmental threats. Results: In this review, we delve into the complex interplay of the three components of OH in relation to ARB and ARGs. Antibiotics used in animal husbandry and plants to promote growth, treat, and prevent infectious diseases lead to the development of antibiotic-resistant bacteria in animals. These bacteria are transmitted from animals to humans through food and environmental exposure. The environment plays a critical role in the circulation and persistence of antibiotic-resistant bacteria and genes, posing a significant threat to human and animal health. This article also highlights how ARGs are spread in the environment through the transfer of genetic material between bacteria. This transfer can occur naturally or through human activities such as the use of antibiotics in agriculture and waste management practices. Conclusion: It is important to integrate the One Health approach into the public health system to effectively tackle the emergence and spread of ARB and genes that code for resistance to different antibiotics.

Potential Causes of Spread of Antimicrobial Resistance and Preventive Measures in One Health Perspective-A Review

Antimicrobial resistance, referring to microorganisms' capability to subsist and proliferate even when there are antimicrobials is a foremost threat to public health globally. The appearance of antimicrobial resistance can be ascribed to anthropological, animal, and environmental factors. Human-related causes include antimicrobial overuse and misuse in medicine, antibiotic-containing cosmetics and biocides utilization, and inadequate sanitation and hygiene in public settings. Prophylactic and therapeutic antimicrobial misuse and overuse, using antimicrobials as feed additives, microbes resistant to antibiotics and resistance genes in animal excreta, and antimicrobial residue found in animal-origin food and excreta are animals related contributive factors for the antibiotic resistance emergence and spread. Environmental factors including naturally existing resistance genes, improper disposal of unused antimicrobials, contamination from waste in public settings, animal farms, and pharmaceutical industries, and the use of agricultural and sanitation chemicals facilitatet its emergence and spread. Wildlife has a plausible role in the antimicrobial resistance spread. Adopting a one-health approach involving using antimicrobials properly in animals and humans, improving sanitation in public spaces and farms, and implementing coordinated governmental regulations is crucial for combating antimicrobial resistance. Collaborative and cooperative involvement of stakeholders in public, veterinary and ecological health sectors is foremost to circumvent the problem effectively.

Antimicrobial consumption surveillance in Uganda: Results from an analysis of national import data for the human health sector, 2018-2021

BACKGROUND

The surveillance of antimicrobial consumption (AMC) is critical to developing appropriate antimicrobial stewardship interventions. It is a key component of World Health Organization's (WHO) Global Action Plan on Antimicrobial Resistance and the Uganda Antimicrobial Resistance National Action Plan 2018-2023. Our study's objective was to determine the national consumption of all antimicrobials.

METHODS

Data on all imported antimicrobials were retrieved from paper-based records and entered in the web-based National Drug Authority (NDA) management information system from 2021. The import data for the year is a proxy for nationwide consumption because they account for 95% of all medical products. The NDA authorizes all imports to the country regardless of final distribution in the supply chain. The data were analyzed in accordance with WHO Anatomical Therapeutic Chemical codes and defined daily dose (DDD) methodology. We also retrieved consumption data for 2018, 2019, and 2020 that were previously submitted by Uganda to WHO's Global Antimicrobial Resistance and Use Surveillance System.

RESULTS

In 2021, the average DDD per 1000 inhabitants was 29.02 for all antimicrobials; 80.7% of antimicrobials consumed were oral. Penicillins (27.6%) were the most consumed antimicrobial class, followed by sulfonamides and trimethoprim (15.5%). Based on WHO's Access, Watch, and Reserve (AWaRe) antibiotic classification, 62.91% of AMC was from the access class, with watch class averaging 14.51% in the period 2018-2021. Watch class AMC spiked in 2021 (34.2%) during COVID-19 pandemic compared to 2020 (24.29%). Azithromycin and ciprofloxacin were the most consumed watch class antimicrobials in 2021.

CONCLUSIONS

The relatively high consumption of injectable antimicrobials and year over year increase in watch class AMC requires urgent stewardship interventions. Further work is needed to establish a system for longitudinal AMC surveillance that is well resourced and funded to overcome the challenges of estimation and provide more accurate data on consumption and use patterns.

Novel Iron Chelators, Super-Polyphenols, Show Antimicrobial Effects against Cariogenic Streptococcus mutans

Dental caries are an oral infectious disease that can affect human health both orally and systemically. It remains an urgent issue to establish a novel antibacterial method to prevent oral infection for a healthy life expectancy. The aim of this study was to evaluate the inhibitory effects of novel iron chelators, super-polyphenols (SPs), on the cariogenic bacterium Streptococcus mutans, in vitro. SPs were developed to reduce the side effects of iron chelation therapy and were either water-soluble or insoluble depending on their isoforms. We found that SP6 and SP10 inhibited bacterial growth equivalent to povidone-iodine, and viability tests indicated that their effects were bacteriostatic. These results suggest that SP6 and SP10 have the potential to control oral bacterial infections such as Streptococcus mutans.

Modelling antimicrobial resistance transmission to guide personalized antimicrobial stewardship interventions and infection control policies in healthcare setting: a pilot study

Infection control programs and antimicrobial stewardship have been proven effective in reducing the burden of diseases due to multidrug-resistant organisms, but quantifying the effect of each intervention is an open issue. For this aim, we propose a model to characterize the effect of interventions at single ward level. We adapted the Ross-Macdonald model to describe hospital cross-transmission dynamics of carbapenem resistant Klebsiella pneumoniae (CRKP), considering healthcare workers as the vectors transmitting susceptible and resistant pathogens among admitted patients. The model parameters were estimated from a literature review, further adjusted to reproduce observed clinical outcomes, and validated using real life data from a 2-year study in a university hospital. The model has been further explored through extensive sensitivity analysis, in order to assess the relevance of single interventions as well as their synergistic effects. Our model has been shown to be an effective tool to describe and predict the impact of interventions in reducing the prevalence of CRKP colonisation and infection, and can be extended to other specific hospital and pathological scenarios to produce tailored estimates of the most effective strategies.

Most hospital patients at risk for bacterial infection undergo an anesthetic: implications for infection control practices related to the anesthesia workspace

PURPOSE

Even with nearly 100% compliance with prophylactic antibiotic protocols, many surgical patients (> 5%) develop surgical site infections, some caused by pathogens transmitted from the anesthesia workspace (e.g., anesthesia machine), including multidrug-resistant Staphylococcus aureus. Reducing contamination of the anesthesia workspace substantively reduces the risk of surgical site infections. We estimated the percentage of hospital patients at risk for health care-associated infections who may benefit from the application of basic preventive measures under the control of anesthesia practitioners (e.g., their hand hygiene).

METHODS

We conducted a retrospective cohort study which included every patient admitted to the University of Miami Health System from April 2021 through March 2022 for hospitalization, surgery, emergency department visits, or outpatient visits. Lists were created for the start date and times of every parenteral antibiotic administered and every anesthetic.

RESULTS

Among 28,213 patient encounters including parenteral antibiotic(s), more than half (64.3%) also included an anesthetic (99% confidence interval, 62.2 to 66.6). The hypothesis that most antibiotics were administered during encounters when a patient underwent an anesthetic was accepted (P < 0.001). This observation may seem counterintuitive because parenteral antibiotics were administered for fewer than half of the 53,235 anesthetics (34.2%). The result was a consequence of most anesthetics (63.5%) at the health system being conducted in nonoperating room locations, and only 7.2% of such patients received a parenteral antibiotic.

CONCLUSIONS

Because approximately two-thirds of patients who receive an intravenous antibiotic also undergo an anesthetic, greater use of effective infection control measures in the anesthesia operating room workspace has the potential to substantively reduce overall rates of hospital infections.

Antimicrobial Resistance Patterns and Risk Factors Associated with ESBL-Producing and MDR Escherichia coli in Hospital and Environmental Settings in Lusaka, Zambia: Implications for One Health, Antimicrobial Stewardship and Surveillance Systems

Antimicrobial resistance (AMR) is a public health problem threatening human, animal, and environmental safety. This study assessed the AMR profiles and risk factors associated with Escherichia coli in hospital and environmental settings in Lusaka, Zambia. This cross-sectional study was conducted from April 2022 to August 2022 using 980 samples collected from clinical and environmental settings. Antimicrobial susceptibility testing was conducted using BD PhoenixTM 100. The data were analysed using SPSS version 26.0. Of the 980 samples, 51% were from environmental sources. Overall, 64.5% of the samples tested positive for E. coli, of which 52.5% were from clinical sources. Additionally, 31.8% were ESBL, of which 70.1% were clinical isolates. Of the 632 isolates, 48.3% were MDR. Most clinical isolates were resistant to ampicillin (83.4%), sulfamethoxazole/trimethoprim (73.8%), and ciprofloxacin (65.7%) while all environmental isolates were resistant to sulfamethoxazole/trimethoprim (100%) and some were resistant to levofloxacin (30.6%). The drivers of MDR in the tested isolates included pus (AOR = 4.6, CI: 1.9-11.3), male sex (AOR = 2.1, CI: 1.2-3.9), and water (AOR = 2.6, CI: 1.2-5.8). This study found that E. coli isolates were resistant to common antibiotics used in humans. The presence of MDR isolates is a public health concern and calls for vigorous infection prevention measures and surveillance to reduce AMR and its burdens.

Early Discontinuation of Antibiotics in Patients Admitted With Clinically Suspected Serious Infection but Negative Cultures: Retrospective Cohort Study of Practice Patterns and Outcomes at 111 US Hospitals

Background

The optimal duration for antibiotics in patients hospitalized with culture-negative serious infection (CNSI) is unknown. We compared outcomes in patients with CNSI treated with 3 or 4 vs ≥5 days of antibiotics.

Methods

CNSI was identified among adults admitted to 111 US hospitals between 2009 and 2014 via electronic health record data, defined as suspected serious infection (blood cultures drawn and ≥3 days of antibiotics) and negative culture- and nonculture-based tests for infection. Patients treated with antibiotics on their last hospital day and patients with diagnosis codes for sepsis-mimicking conditions were excluded. Among patients without fevers/hypothermia or vasopressors by day 3, we calculated odds ratios for in-hospital mortality or discharge to hospice associated with 3 or 4 vs ≥5 days of antibiotics, adjusting for confounders.

Results

Antibiotics were discontinued in 3 or 4 days in 1862 (9%) of 20 714 patients with CNSI. Early discontinuation was not associated with higher mortality odds overall (adjusted odds ratio [aOR], 1.27; 95% CI, .98-1.65), in patients presenting with (1.39; .88-2.22) and without sepsis (1.17; .81-1.69), and in those with pulmonary (1.23; .65-2.34) and nonpulmonary CNSI (1.30; .99-1.72). Early discontinuation appeared detrimental with propensity score weighting (aOR, 1.36; 95% CI, 1.03-1.80) and when retaining patients with sepsis mimics (1.38; 1.16-1.65), but it was protective (0.48; .37-.64]) when retaining patients who received antibiotics on their last hospital day.

Conclusions

Early discontinuation of antibiotics in CNSI was not associated with significant harm in our primary analysis, but different conclusions based on alternative analytic decisions, as well as risk of residual confounding, indicate that randomized controlled trials are needed.

Preparation and Characterization of Polycaprolactone (PCL) Antimicrobial Wound Dressing Loaded with Pomegranate Peel Extract

In recent years, medicinal plant extracts have received remarkable attention due to their wound-healing properties. In this study, polycaprolactone (PCL) electrospun nanofiber membranes incorporated with different concentrations of pomegranate peel extract (PPE) were prepared. The results of the SEM and FTIR experiments demonstrated that the morphology of nanofiber is smooth, fine, and bead-free, and the PPE was well introduced into the nanofiber membranes. Moreover, the outcomes of the mechanical property tests demonstrated that the nanofiber membrane made of PCL and loaded with PPE exhibited remarkable mechanical characteristics, indicating that it could fulfill the essential mechanical requisites for wound dressings. The findings of the in vitro drug release investigations indicated that PPE was instantly released within 20 h and subsequently released gradually over an extended period by the composite nanofiber membranes. Meanwhile, the DPPH radical scavenging test confirmed that the nanofiber membranes loaded with PPE exhibited significant antioxidant properties. Antimicrobial experiments showed higher PPE loading, and the nanofiber membranes showed higher antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans. The results of the cellular experiments showed that the composite nanofiber membranes were nontoxic and promoted the proliferation of L929 cells. In summary, electrospun nanofiber membranes loaded with PPE can be used as a wound dressing.

Antimicrobial resistance in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

Frequent use of antibiotics in patients with COVID-19 threatens to exacerbate antimicrobial resistance. We aimed to establish the prevalence and predictors of bacterial infections and antimicrobial resistance in patients with COVID-19.

METHODS

We did a systematic review and meta-analysis of studies of bacterial co-infections (identified within ≤48 h of presentation) and secondary infections (>48 h after presentation) in outpatients or hospitalised patients with COVID-19. We searched the WHO COVID-19 Research Database to identify cohort studies, case series, case-control trials, and randomised controlled trials with populations of at least 50 patients published in any language between Jan 1, 2019, and Dec 1, 2021. Reviews, editorials, letters, pre-prints, and conference proceedings were excluded, as were studies in which bacterial infection was not microbiologically confirmed (or confirmed via nasopharyngeal swab only). We screened titles and abstracts of papers identified by our search, and then assessed the full text of potentially relevant articles. We reported the pooled prevalence of bacterial infections and antimicrobial resistance by doing a random-effects meta-analysis and meta-regression. Our primary outcomes were the prevalence of bacterial co-infection and secondary infection, and the prevalence of antibiotic-resistant pathogens among patients with laboratory-confirmed COVID-19 and bacterial infections. The study protocol was registered with PROSPERO (CRD42021297344).

FINDINGS

We included 148 studies of 362  976 patients, which were done between December, 2019, and May, 2021. The prevalence of bacterial co-infection was 5·3% (95% CI 3·8-7·4), whereas the prevalence of secondary bacterial infection was 18·4% (14·0-23·7). 42 (28%) studies included comprehensive data for the prevalence of antimicrobial resistance among bacterial infections. Among people with bacterial infections, the proportion of infections that were resistant to antimicrobials was 60·8% (95% CI 38·6-79·3), and the proportion of isolates that were resistant was 37·5% (26·9-49·5). Heterogeneity in the reported prevalence of antimicrobial resistance in organisms was substantial (I2=95%).

INTERPRETATION

Although infrequently assessed, antimicrobial resistance is highly prevalent in patients with COVID-19 and bacterial infections. Future research and surveillance assessing the effect of COVID-19 on antimicrobial resistance at the patient and population level are urgently needed.

FUNDING

WHO.

Probiotic lactic acid bacteria as a means of preventing in vitro urinary catheter colonization and biofilm formation

BACKGROUND

Catheter-associated urinary tract infections (CAUTIs) are the most common infections found in healthcare facilities. Urinary catheters predispose the development of CAUTIs by destroying natural barriers and providing a source for infection and biofilm formation (BF). This study aimed to evaluate probiotic lactic acid bacteria (LAB) as a means of preventing in vitro urinary catheter colonization and BF.

METHODS

Cross-sectional screening, followed by an experimental study, was conducted on 120 catheterized patients admitted to the urology department in a tertiary care hospital for 7 months. The isolated and identified uropathogens were tested for their antimicrobial susceptibility patterns by the disk diffusion method according to Clinical and Laboratory Standards Institute recommendations and examined for their ability to produce biofilms using a microtiter plate (MtP) assay. Five LAB (Lactobacillus acidophilus (L. acidophilus), Bifidobacterium bifidum (B. bifidum), L. paracasei, L. pentosus, and L. plantarum) were identified and examined for preventing in vitro colonization and BF of some isolated uropathogens on Foley urinary catheter surfaces.

RESULTS

Of the 120 samples collected, 32.5% were found to be associated with CAUTIs. Of isolated organisms, 74.4% were gram-negative bacilli, while gram-positive cocci represented 14%, and only 11.6% were of the Candida species. About two-thirds of isolated uropathogens were biofilm formers. All five probiotic strains had inhibitory effects on the growth of all the uropathogens tested but with varying intensities according to the duration of application after 2, 4, and 6 days.

CONCLUSIONS

The prevalence of CAUTIs was high, and the predominant bacterial isolates were gram-negative bacilli. Many of the studied uropathogens were biofilm formers. The bacterial isolates had a higher prevalence of resistance to commonly prescribed antimicrobial agents. Probiotics have the potential to prevent in vitro urinary catheter colonization and inhibit BF. Pre-coating urinary catheters with probiotics is recommended after ensuring the safety of probiotics' use in vivo by carrying out further large-scale studies.

Validating agent-based simulation model of hospital-associated Clostridioides difficile infection using primary hospital data

As agent-based models (ABMs) are increasingly used for modeling infectious diseases, model validation is becoming more crucial. In this study, we present an alternate approach to validating hospital ABMs that focuses on replicating hospital-specific conditions and proposes a new metric for validating the social-environmental network structure of ABMs. We adapted an established ABM representing Clostridioides difficile infection (CDI) spread in a generic hospital to a 426-bed Midwestern academic hospital. We incorporated hospital-specific layout, agent behaviors, and input parameters estimated from primary hospital data into the model, referred to as H-ABM. We compared the predicted CDI rate against the observed rate from 2013-2018. We used colonization pressure, a measure of nearby infectious agents, to validate the socio-environmental agent networks in the ABM. Finally, we conducted additional experiments to compare the performance of individual infection control interventions in the H-ABM and the generic model. We find that the H-ABM is able to replicate CDI trends during 2013-2018, including a roughly 46% drop during a period of greater infection control investment. High CDI burden in socio-environmental networks was associated with a significantly increased risk of C. difficile colonization or infection (Risk ratio: 1.37; 95% CI: [1.17, 1.59]). Finally, we found that several high-impact infection control interventions have diminished impact in the H-ABM. This study presents an alternate approach to validation of ABMs when large-scale calibration is not appropriate for specific settings and proposes a new metric for validating socio-environmental network structure of ABMs. Our findings also demonstrate the utility of hospital-specific modeling.

Antibiotic consumption in secondary and tertiary hospitals in Colombia: national surveillance from 2018-2020

Objective

To assess the compliance in secondary and tertiary level hospitals with monthly reporting of antibiotic consumption to the Colombian National Public Health Surveillance System (SIVIGILA-INS), and to describe reported antibiotic consumption during 2018-2020.

Methods

This study involved a secondary analysis of antibiotic consumption data reported to SIVIGILA-INS. Frequency of hospital reporting was assessed and compared against expected reports, disaggregated by intensive care units (ICU)/non-ICU wards and geographical regions. Consumption was expressed as defined daily dose (DDD) per 100 occupied beds for seven antibiotics.

Results

More than 70% of hospitals reported antibiotic consumption at least once in each of the three years (79% in ICU and 71% in non-ICU wards). Of these, ICU monthly reporting was complete (12 monthly reports per year) for 59% in the period 2018-2019 but only 4% in 2020. Non-ICU reporting was complete for 52% in 2019 and for 2% in 2020. Most regions had an overall decrease in reporting in 2020. Analysis of antibiotic consumption showed an increase for piperacillin/tazobactam, ertapenem, and cefepime from 2019 to 2020.

Conclusions

There were gaps in the consistency and frequency of reporting. Efforts are needed to improve compliance with monthly reporting, which declined in 2020, possibly due to the COVID-19 pandemic. Non-compliance on reporting and data quality issues should be addressed with the hospitals to enable valid interpretation of antibiotic consumption trends.

Cost-effectiveness of strategies to control the spread of carbapenemase-producing Enterobacterales in hospitals: a modelling study

Background

Spread of resistant bacteria causes severe morbidity and mortality. Stringent control measures can be expensive and disrupt hospital organization. In the present study, we assessed the effectiveness and cost-effectiveness of control strategies to prevent the spread of Carbapenemase-producing Enterobacterales (CPE) in a general hospital ward (GW).

Methods

A dynamic, stochastic model simulated the transmission of CPE by the hands of healthcare workers (HCWs) and the environment in a hypothetical 25-bed GW. Input parameters were based on published data; we assumed the prevalence at admission of 0.1%. 12 strategies were compared to the baseline (no control) and combined different prevention and control interventions: targeted or universal screening at admission (TS or US), contact precautions (CP), isolation in a single room, dedicated nursing staff (DNS) for carriers and weekly screening of contact patients (WSC). Time horizon was one year. Outcomes were the number of CPE acquisitions, costs, and incremental cost-effectiveness ratios (ICER). A hospital perspective was adopted to estimate costs, which included laboratory costs, single room, contact precautions, staff time, i.e. infection control nurse and/or dedicated nursing staff, and lost bed-days due to prolonged hospital stay of identified carriers. The model was calibrated on actual datasets. Sensitivity analyses were performed.

Results

The baseline scenario resulted in 0.93 CPE acquisitions/1000 admissions and costs 32,050 €/1000 admissions. All control strategies increased costs and improved the outcome. The efficiency frontier was represented by: (1) TS with DNS at a 17,407 €/avoided CPE case, (2) TS + DNS + WSC at a 30,700 €/avoided CPE case and (3) US + DNS + WSC at 181,472 €/avoided CPE case. Other strategies were dominated. Sensitivity analyses showed that TS + CP might be cost-effective if CPE carriers are identified upon admission or if the cases have a short hospital stay. However, CP were effective only when high level of compliance with hand hygiene was obtained.

Conclusions

Targeted screening at admission combined with DNS for identified CPE carriers with or without weekly screening were the most cost-effective options to limit the spread of CPE. These results support current recommendations from several high-income countries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01149-0.

Isolation and characterisation of carbapenem-resistant Pseudomonas aeruginosa from hospital environments in tertiary care hospitals in Dhaka, Bangladesh

OBJECTIVES

Increasing evidence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) infection in healthcare facilities poses an alarming threat to public health. There is little evidence on the occurrence of this organism in Bangladeshi hospitals.

METHODS

We collected 117 environmental swab samples from two tertiary care hospitals in Dhaka, Bangladesh and tested for Pseudomonas species by nonselective enrichment of swabs followed by plating on Cetrimide agar. We confirmed the isolates as P. aeruginosa by API 20NE test and polymerase chain reaction Polymerase Chain Reaction (PCR) for 16S rRNA gene. We analysed P. aeruginosa isolates for susceptibility against 15 clinically important antibiotics and tested the carbapenem-resistant isolates for metallo β-lactamase (MBL). All CRPA isolates were characterised for carbapenem-resistant genes, virulence genes and biofilm formation genes.

RESULTS

Of 117 swab samples, 82 (70%) were tested positive for P. aeruginosa. All P. aeruginosa isolates were multidrug-resistant, and 39% (n = 32) of isolates were CRPA. Around 56% (n = 18) of CRPA were MBL-producing; 22% (n = 7) of isolates were positive for carbapenemase gene bla_NDM followed by 16% (n = 5) for bla_VIM and 13% (n = 4) for bla_IMP. Sequencing identified these genes as bla_NDM-1, bla_IMP-13, bla_VIM-2 variants. Based on optical density values, 94% (n = 30) of CRPA isolates were capable of producing biofilms. All CRPA isolates (n = 32) were positive for at least 1 of 6 biofilm-associated genes and 4 of 12 virulence genes tested in the study.

CONCLUSION

Hospital environments in Bangladesh are contaminated with highly virulent CRPA, which might be a potential source of hospital-acquired infections, accentuating the need for strengthening hospital infection control programs.

Genomic, morphological, and biochemical analyses of a multi-metal resistant but multi-drug susceptible strain of Bordetella petrii from hospital soil

Contamination of soil by antibiotics and heavy metals originating from hospital facilities has emerged as a major cause for the development of resistant microbes. We collected soil samples surrounding a hospital effluent and measured the resistance of bacterial isolates against multiple antibiotics and heavy metals. One strain BMCSI 3 was found to be sensitive to all tested antibiotics. However, it was resistant to many heavy metals and metalloids like cadmium, chromium, copper, mercury, arsenic, and others. This strain was motile and potentially spore-forming. Whole-genome shotgun assembly of BMCSI 3 produced 4.95 Mb genome with 4,638 protein-coding genes. The taxonomic and phylogenetic analysis revealed it, to be a Bordetella petrii strain. Multiple genomic islands carrying mobile genetic elements; coding for heavy metal resistant genes, response regulators or transcription factors, transporters, and multi-drug efflux pumps were identified from the genome. A comparative genomic analysis of BMCSI 3 with annotated genomes of other free-living B. petrii revealed the presence of multiple transposable elements and several genes involved in stress response and metabolism. This study provides insights into how genomic reorganization and plasticity results in evolution of heavy metals resistance by acquiring genes from its natural environment.

Predictive Factors, Treatment, and Outcomes of Coagulase-Negative Staphylococcal Peritonitis in Malaysian Peritoneal Dialysis Patients: A Single-Center Study

Aims

Coagulase-negative Staphylococci (CoNS) are frequently isolated in peritoneal dialysis (PD)-related peritonitis with a high rate of relapse and repeat peritonitis after initial response to antimicrobials. The optimal treatment regimen for CoNS peritonitis remains debatable. Hence, this study aimed to describe the clinical and microbiologic characteristics of CoNS peritonitis in a PD center and determine predictive factors influencing the outcomes.

Methods

All cases of CoNS peritonitis in Selayang Hospital between 2011 and 2019 were reviewed retrospectively.

Results

A total of 906 episodes of peritonitis were recorded; 140 episodes (15%) in 98 patients were caused by CoNS. The oxacillin and gentamicin resistance rates were 47% and 46%, respectively. The overall primary response rate was 90%, and the complete cure rate was 79%. Patients with concomitant exit-site infection (odds ratio (OR) 0.06, 95% confidence interval (CI) 0.01 to 0.40, P < 0.01) and history of recent systemic antibiotic use (OR 0.04, 95% CI 0.01 to 0.82, P=0.04) were less likely to achieve primary response. CoNS episodes that were treated with beta-lactam-based or vancomycin-based therapy had a similar primary response rate and complete cure rate. The rates of relapse and repeat were 12% and 16%, respectively. Relapsed episodes (OR 0.35, 95% CI 0.13 to 0.97, P=0.04) had a significantly lower complete cure rate than the first episodes.

Conclusion

Relapsed CoNS peritonitis was common and was associated with worse outcomes than the first episode of CoNS peritonitis. Oxacillin resistance was common, but the treatment outcome remained favourable when a beta-lactam-based regimen was used as empirical therapy.

Modelling of the transmission dynamics of carbapenem-resistant Klebsiella pneumoniae in hospitals and design of control strategies

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a major threat to global public health. Epidemiological and infection controls associated with CRKP are challenging because of several potential elements involved in a complicated cycle of transmission. Here, we proposed a comprehensive mathematical model to investigate the transmission dynamics of CRKP, determine factors affecting the prevalence, and evaluate the impact of interventions on transmission. The model includes the essential compartments, which are uncolonized, asymptomatic colonized, symptomatic colonized, and relapsed patients. Additionally, symptomatic colonized and relapsed patients were further classified into subpopulations according to their number of treatment failures or relapses. We found that the admission of colonized patients and use of antibiotics significantly impacted the endemic transmission in health care units. Thus, we introduced the treatment efficacy, defined by combining the treatment duration and probability of successful treatment, to characterize and describe the effects of antibiotic treatment on transmission. We showed that a high antibiotic treatment efficacy results in a significantly reduced likelihood of patient readmission in the health care unit. Additionally, our findings demonstrate that CRKP transmission with different epidemiological characteristics must be controlled using distinct interventions.

Factors Associated With Prolonged Antibiotic Use in the Setting of Suspected Pneumonia and Negative Bronchoalveolar Lavage Cultures

Background: Diagnostic criterion for pneumonia includes clinical data and bronchoalveolar lavage cultures (BALCx) to identify pathogens. Although ~60% of BALCx are negative, there may be reluctance to discontinue antibiotics, leading to prolonged antibiotic use (PAU). Objective: The purpose of this study is to compare outcomes of subjects with negative BALCx with PAU versus without prolonged antibiotic use (nPAU). Methods: A retrospective cohort study was conducted including subjects admitted to the intensive care unit (ICU), with suspected pneumonia, and negative BALCx. Data were compared based on length of exposure to antibiotics, PAU (antibiotics >4 days) versus nPAU (antibiotics <4 days). Results: A total of 128 subjects were included, 57 in the PAU group and 71 in the nPAU group. Baseline demographics were similar between groups. Severity of illness measured by multiple organ dysfunction scores at time of bronchoalveolar lavage (BAL) collection to final result showed a statistically significant decrease in the PAU group but not in the nPAU group. No differences were found in ICU days, ventilator-free days, or mortality; however, length of stay was longer for PAU (23 vs. 17, p = .04). In the PAU group, there were fewer BALCx results of "no growth" (23% vs. 45%, p = .04), more positive gram stains (83% vs. 60%, p = .01) and more positive non-BALCx (40% vs. 14%, p = .01). In a multivariate analysis, factors associated with PAU were positive BAL gram stains (adjusted odds ratio [aOR] 3.1, p = .037) and positive non-BALCx (aOR 4.7, p = .002). Conclusion: For subjects with suspected pneumonia and negative BALCx, positive non-BALCx and positive BALCx gram stain influenced the length of exposure of antibiotics.

Antibiotic resistance in microbes: History, mechanisms, therapeutic strategies and future prospects

Antibiotics have been used to cure bacterial infections for more than 70 years, and these low-molecular-weight bioactive agents have also been used for a variety of other medicinal applications. In the battle against microbes, antibiotics have certainly been a blessing to human civilization by saving millions of lives. Globally, infections caused by multidrug-resistant (MDR) bacteria are on the rise. Antibiotics are being used to combat diversified bacterial infections. Synthetic biology techniques, in combination with molecular, functional genomic, and metagenomic studies of bacteria, plants, and even marine invertebrates are aimed at unlocking the world's natural products faster than previous methods of antibiotic discovery. There are currently only few viable remedies, potential preventive techniques, and a limited number of antibiotics, thereby necessitating the discovery of innovative medicinal approaches and antimicrobial therapies. MDR is also facilitated by biofilms, which makes infection control more complex. In this review, we have spotlighted comprehensively various aspects of antibiotics viz. overview of antibiotics era, mode of actions of antibiotics, development and mechanisms of antibiotic resistance in bacteria, and future strategies to fight the emerging antimicrobial resistant threat.

Carriage Prevalence of Extended-Spectrum β-Lactamase Producing Enterobacterales in Outpatients Attending Community Health Centers in Blantyre, Malawi

Antimicrobial resistance due to extended-spectrum β-lactamase (ESBL) production by Enterobacterales is a global health problem contributing to increased morbidity and mortality, particularly in resource-constrained countries. We aimed to determine the prevalence of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) in community patients in Blantyre, Malawi. Clinical samples were collected from 300 patients and screened for ESBL-E using a CHROMagar^TM ESBL medium. Confirmation of ESBL production was done by a combination disk test (CDT). The prevalence of community-acquired ESBL-E was 16.67% (50/300, 95% CI = 12.43–20.91%). The most common ESBL-E species isolated was Escherichia coli (66%). All ESBL-E isolates were resistant to Trimethoprim-Sulfamethoxazole except for 2% of E. coli. Besides this, all ESBL-E were susceptible to Imipenem and only 4% were resistant to Meropenem. No patients with a positive ESBL-E phenotype had a history of hospital admission in the last three months, and the carriage of ESBL-E was neither associated with the demographic nor the clinical characteristics of participants. Our findings reveal a low presence of ESBL-E phenotypes in community patients. The low prevalence of ESBL-E in the community settings of Blantyre can be maintained if strong infection and antimicrobial use-control strategies are implemented.

Bacterial co-infection in patients with SARS-CoV-2 in the Kingdom of Bahrain

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic presents a significant challenge to the medical profession, increasing in the presence of microbial co-infection. Bacterial and Fungal co-infections increase the risk of morbidity and mortality in patients with COVID-19.

AIM

To study the bacterial profile in patients with COVID-19 who needed admission to receive treatment in the main centres concerned with managing COVID-19 disease in the Kingdom of Bahrain.

METHODS

The study was a retrospective observational analysis of the bacterial profile and the bacterial resistance in patients with confirmed COVID-19 disease who needed admission to receive treatment in the main centres assigned to manage patients with COVID-19 disease in the Kingdom of Bahrain from February to October 2020. We used the electronic patients' records and the microbiology laboratory data to identify patients' demographics, clinical data, microbial profile, hospital or community-acquired, and the outcomes.

RESULTS

The study included 1380 patients admitted with confirmed COVID-19 disease during the study period. 51% were admitted from February to June, and 49% were admitted from July to October 2020, with a recurrence rate was 0.36%. There was a significant increase in bacterial and fungal co-infection in the second period compared to the first period. The most common isolated organisms were the gram-negative bacteria (mainly Klebsiella pneumoniae, Pseudomonas aeruginosa, multi-drug resistant Acinetobacter baumannii, and Escherichia coli), the gram-positive bacteria (mainly coagulase negative Staphylococci, Enterococcus faecium, Enterococcus faecalis, Staphylococcus aureus) and fungaemia (Candida galabrata, Candida tropicalis, Candida albicans, Aspergillus fumigatus, Candida parapsilosis, Aspergillus niger). The hospital-acquired infection formed 73.8%, 61.6%, 100% gram-negative, gram-positive and fungaemia. Most of the hospital-acquired infection occurred in the second period with a higher death rate than community-acquired infections.

CONCLUSION

Bacterial and fungal co-infections in patients admitted with confirmed COVID-19 disease pose higher morbidity and mortality risks than those without co-infections. We should perform every effort to minimize these risks.

Bacterial co-infection in patients with SARS-CoV-2 in the Kingdom of Bahrain

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic presents a significant challenge to the medical profession, increasing in the presence of microbial co-infection. Bacterial and Fungal co-infections increase the risk of morbidity and mortality in patients with COVID-19.

AIM

To study the bacterial profile in patients with COVID-19 who needed admission to receive treatment in the main centres concerned with managing COVID-19 disease in the Kingdom of Bahrain.

METHODS

The study was a retrospective observational analysis of the bacterial profile and the bacterial resistance in patients with confirmed COVID-19 disease who needed admission to receive treatment in the main centres assigned to manage patients with COVID-19 disease in the Kingdom of Bahrain from February to October 2020. We used the electronic patients’ records and the microbiology laboratory data to identify patients’ demographics, clinical data, microbial profile, hospital or community-acquired, and the outcomes.

RESULTS

The study included 1380 patients admitted with confirmed COVID-19 disease during the study period. 51% were admitted from February to June, and 49% were admitted from July to October 2020, with a recurrence rate was 0.36%. There was a significant increase in bacterial and fungal co-infection in the second period compared to the first period. The most common isolated organisms were the gram-negative bacteria (mainly Klebsiella pneumoniae, Pseudomonas aeruginosa, multi-drug resistant Acinetobacter baumannii, and Escherichia coli), the gram-positive bacteria (mainly coagulase negative Staphylococci, Enterococcus faecium, Enterococcus faecalis, Staphylococcus aureus) and fungaemia (Candida galabrata, Candida tropicalis, Candida albicans, Aspergillus fumigatus, Candida parapsilosis, Aspergillus niger). The hospital-acquired infection formed 73.8%, 61.6%, 100% gram-negative, gram-positive and fungaemia. Most of the hospital-acquired infection occurred in the second period with a higher death rate than community-acquired infections.

CONCLUSION

Bacterial and fungal co-infections in patients admitted with confirmed COVID-19 disease pose higher morbidity and mortality risks than those without co-infections. We should perform every effort to minimize these risks.

National Antimicrobial Consumption: Analysis of Central Warehouses Supplies to In-Patient Care Health Facilities from 2017 to 2019 in Uganda

Antimicrobial consumption (AMC) surveillance at global and national levels is necessary to inform relevant interventions and policies. This study analyzed central warehouse antimicrobial supplies to health facilities providing inpatient care in Uganda. We collected data on antimicrobials supplied by National Medical Stores (NMS) and Joint Medical Stores (JMS) to 442 health facilities from 2017 to 2019. Data were analyzed using the World Health Organization methodology for AMC surveillance. Total quantity of antimicrobials in defined daily dose (DDD) were determined, classified into Access, Watch, Reserve (AWaRe) and AMC density was calculated. There was an increase in total DDDs distributed by NMS in 2019 by 4,166,572 DDD. In 2019, Amoxicillin (27%), Cotrimoxazole (20%), and Metronidazole (12%) were the most supplied antimicrobials by NMS while Doxycycline (10%), Amoxicillin (19%), and Metronidazole (10%) were the most supplied by JMS. The majority of antimicrobials supplied by NMS (81%) and JMS (66%) were from the Access category. Increasing antimicrobial consumption density (DDD per 100 patient days) was observed from national referral to lower-level health facilities. Except for NMS in 2019, total antimicrobials supplied by NMS and JMS remained the same from 2017 to 2019. This serves as a baseline for future assessments and monitoring of stewardship interventions.

Laboratory medicine: The exemplar for value-based healthcare

Value-Based Healthcare (VBHC) aims to improve the overall quality, safety, and sustainability of healthcare while reducing delivery costs of more effective care. Despite advantages associated with VBHC transformation, the road to its adoption has been lengthy. Laboratory Medicine (LM) is in a prime position to lead the transition to VBHC because of its key role in diagnosis and treatment of patients. Laboratory medicine results inform/influence 50% to 70% of all clinical decisions. This article summarizes some issues associated with adoption of VBHC and related healthcare innovations and suggests potential approaches using LM-specific examples to help accelerate adoption. Laboratory medicine is both a useful model for VBHC implementation and facilitator for related innovation adoption by helping to target patient populations that would benefit most from specific interventions. The critical value of rapidly adopted diagnostic technologies used during the COVID-19 pandemic and economic recovery provide important insights about the need to embrace and accelerate VBHC implementation.

The effect of prophylaxis with ertapenem versus cefuroxime/metronidazole on intestinal carriage of carbapenem-resistant or third-generation-cephalosporin-resistant Enterobacterales after colorectal surgery

OBJECTIVES

Compared to cephalosporin-based prophylaxis, ertapenem prophylaxis lowers the risk of surgical site infection among carriers of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PEs) undergoing colorectal surgery. We aimed to determine whether ertapenem prophylaxis leads to increased postoperative colonization with carbapenem-resistant Enterobacterales (CREs) and third-generation-cephalosporin-resistant Enterobacterales (3GCR-Es).

METHODS

This study was nested within a quality improvement study of prophylaxis for ESBL-PE carriers undergoing colorectal surgery. Patients were screened 4-6 days after surgery for carriage of ESBL-PEs or other 3GCR-Es and CREs. When CREs were detected, pre- and postsurgical clones were compared using Fourier-transform infrared (FT-IR) spectroscopy.

RESULTS

The sample consisted of 56 patients who carried ESBL-PEs before surgery and received cefuroxime/metronidazole prophylaxis (Group 1), 66 who carried ESBL-PEs before surgery and received ertapenem (Group 2), and 103 ESBL-PE non-carriers who received cefuroxime/metronidazole prophylaxis (Group 3). CRE carriage was detected postoperatively in one patient (1.5%) in Group 2 versus eight patients (14.3%) in Group 1 (RD -12.8%; 95%CI -22.4% to -3.1%). For seven out of nine patients, preoperative ESBL-PE and postoperative CRE isolates were compared; in five of them, the pre- and postoperative clones were identical. Postoperative 3GCR-E carriage was detected in 37 patients (56.1%) in Group 2 versus 46 patients in Group 1 (82.1%) (aRD -20.7%, 95%CI -37.3% to -4.1%).

CONCLUSIONS

Among ESBL-PE carriers undergoing colorectal surgery, detection of short-term postsurgical colonization by CREs and 3GCR-Es was significantly lower among patients who received ertapenem prophylaxis than those who received cephalosporin-metronidazole prophylaxis. Resistance development in a colonizing bacterial clone, rather than carbapenemase acquisition, was the major mechanism of carbapenem resistance.

The Role of Uniform Meropenem Usage in Acinetobacter baumannii Clone Replacement

The dominant carbapenem resistant Acinetobacter baumannii harboring bla_OXA-23-like carbapenemase was replaced by bla_OXA-40-like carriers in a Hungarian tertiary-care center with high meropenem but relatively low imipenem use. We hypothesized that alterations in antibiotic consumption may have contributed to this switch. Our workgroup previous study examined the relation between resistance spiral and the antibiotic consumption, and the results suggest that the antibiotic usage provoked the increasing resistance in case of A. baumannii. We aimed at measuring the activity of imipenem and meropenem to compare the selection pressure exerted by the different carbapenems in time-kill assays. Strain replacement was confirmed by whole genome sequencing, core-genome multilocus sequence typing (cgMLST), and resistome analysis. Based on results of the time-kill assays, we found a significant difference between two different sequence-types (STs) in case of meropenem, but not in case of imipenem susceptibility. The newly emerged ST636 and ST492 had increased resistance level against meropenem compared to the previously dominant ST2 and ST49. On the other hand, the imipenem and colistin resistance profiles were similar. These results suggest, that the uniform meropenem usage may have contributed to A. baumannii strain replacement in our setting.

Total antibiotic use in a state-wide area and resistance patterns in Brazilian hospitals: an ecologic study

INTRODUCTION

Use of antibiotic and bacterial resistance is the result of a complex interaction not completely understood.

OBJECTIVES

To evaluate the impact of entire antimicrobial use (community plus hospitals) on the incidence of bloodstream infections in intensive care units adjusted by socioeconomic factors, quality of healthcare, and access to the healthcare system.

DESIGN

Ecologic study using a hierarchical spatial model.

SETTING

Data obtained from 309 hospitals located in the state of São Paulo, Brazil from 2008 to 2011.

PARTICIPANTS

Intensive care units located at participant hospitals.

OUTCOME

Hospital acquired bloodstream infection caused by MDRO in ICU patients was our primary outcome and data were retrieved from São Paulo Health State Department. Socioeconomic and healthcare indexes data were obtained from IBGE (Brazilian Foundation in charge of national decennial census) and SEADE (São Paulo Planning and Development Department). Information on antimicrobial sales were obtained from IMS Brazil. We divided antibiotics into four different groups (1-4).

RESULTS

We observed a direct association between the use of group 1 of antibiotics and the incidences of bloodstream infections caused by MRSA (1.12; 1.04-1.20), and CR-Acinetobacter sp. (1.19; 1.10-1.29). Groups 2 and 4 were directly associated to VRE (1.72; 1.13-2.39 and 2.22; 1.62-2.98, respectively). Group 2 was inversely associated to MRSA (0.87; 0.78-0.96) and CR-Acinetobacter sp. (0.79; 0.62-0.97). Group 3 was inversely associated to Pseudomonas aeruginosa (0.69; 0.45-0.98), MRSA (0.85; 0.72-0.97) and VRE (0.48; 0.21-0.84). No association was observed for third generation cephalosporin-resistant Klebsiella pneumoniae and Escherichia coli.

CONCLUSIONS

The association between entire antibiotic use and resistance in ICU was poor and not consistent for all combinations of antimicrobial groups and pathogens even after adjusted by socioeconomic indexes. Selective pressure exerted at the community level seemed not to affect the incidences of MDRO infection observed in intensive care setting.

Patients with Sore Throat: A Survey of Self-Management and Healthcare-Seeking Behavior in 13 Countries Worldwide

Background

Acute sore throat is one of the most common problems for which patients consult their general practitioner and is a key area for inappropriate antibiotic prescribing. The objective of this study was to investigate patients’ attitudes related to healthcare-seeking behavior and self-management of sore throat.

Methods

We conducted an observational, questionnaire-based study across 13 countries (Australia, Brazil, China, France, Germany, Italy, the Philippines, Russia, Saudi Arabia, South Africa, Thailand, the UK and the USA) on respondents who reported having had a sore throat in the previous 12 months. Data were collected on their experiences, contact with healthcare professionals, treatment practices and opinions about antibiotics.

Results

A total of 5196 respondents (approximately 400 per country) completed the survey. Over 80% of respondents sought advice for a sore throat, with 30% consulting a general practitioner. The desire to limit the worsening of symptoms was the main reason for seeking treatment. Other reasons concerned resolving persistent symptoms and reducing the impact on daily life/sleep. Self-management for sore throat was mainly medicated sore throat remedies. “Wanting an antibiotic” was rated much lower (55%) than most other reasons for visiting a doctor, but this differed greatly between countries. The percentage of respondents using antibiotics varied widely, for example, 10% in the UK and 45% in Saudi Arabia. There was considerable variation in the proportion of respondents who thought that antibiotics would be effective against sore throat (from 24% in France to 94% in Saudi Arabia).

Conclusions

Our findings suggest that knowledge of effective treatments for sore throat varied widely. The results of this study should enable healthcare professionals to better anticipate patients’ needs. This will support healthcare professionals in their role as antibiotic stewards, helping to reduce the misuse of antibiotics, and further guiding patients towards symptomatic self-management of sore throat.

Organic and inorganic antibacterial approaches in combating bacterial infection for biomedical application

In spite of antibiotics, antibacterial agents or specifically known as antiseptics are actively explored for the prevention of infection-associated medical devices. Antibacterial agents are introduced to overcome the complication of bacterial resistance which devoted by antibiotics. It can be classified into inorganic and organic, that prominently have impacted bacterial retardation in their own killing mechanism patterns. Therefore, this review paper aimed to provide information on most common used inorganic and organic antibacterial agents which have potential to be utilized in biomedical applications, thus, classifying the trends of antibacterial mechanism on Gram-negative and Gram-positive bacteria. In the beginning, infectious diseases and associated biomedical infections were stated to expose current infection scenarios on medical devices. The general view, application, susceptible bacteria and activation mechanism of inorganic (silver, copper, gold and zinc) and organic (chlorhexidine, triclosan, polyaniline and polyethylenimine) antibacterial agents that are widely proposed for biomedical area, were then gathered and reviewed. In the latter part of the study, the intact mechanisms of inorganic and organic antibacterial agents in retarding bacterial growth were classified and summarized based on its susceptibility on Gram-negative and Gram-positive bacteria. Most of inorganic antibacterial agents are in the form of metal, which release its ions to retard prominently Gram-negative bacteria. While organic antibacterial agents are susceptible to Gram-positive bacteria through organelle modification and disturbance of bio-chemical pathway. However, the antibacterial effects of each antibacterial agent are also depending on its effective mechanism and the species of bacterial strain. These compilation reviews and classification mechanisms are beneficial to assist the selection of antibacterial agents to be incorporated on/within biomaterials, based on its susceptible bacteria. Besides, the combination of several antibacterial agents with different susceptibilities will cover a wide range of antibacterial spectrum.

Impact of microbiome-based interventions on gastrointestinal pathogen colonization in the intensive care unit

In the intensive care unit (ICU), colonization of the gastrointestinal tract by potentially pathogenic bacteria is common and often precedes clinical infection. Though effective in the short term, traditional antibiotic-based decolonization methods may contribute to rising resistance in the long term. Novel therapies instead focus on restoring gut microbiome equilibrium to achieve pathogen colonization resistance. This review summarizes the existing data regarding microbiome-based approaches to gastrointestinal pathogen colonization in ICU patients with a focus on prebiotics, probiotics, and synbiotics.

Impact of antimicrobial therapy on the gut microbiome

The gut microbiome is now considered an organ unto itself and plays an important role in health maintenance and recovery from critical illness. The commensal organisms responsible for the framework of the gut microbiome are valuable in protection against disease and various physiological tasks. Critical illness and the associated interventions have a detrimental impact on the microbiome. While antimicrobials are one of the fundamental and often life-saving modalities in septic patients, they can also pave the way for subsequent harm because of the resulting damage to the gut microbiome. Contributing to many of the non-specific signs and symptoms of sepsis, the balance between the overuse of antimicrobials and the clinical need in these situations is often difficult to delineate. Given the potency of antimicrobials utilized to treat septic patients, the effects on the gut microbiome are often rapid and long-lasting, in which case full recovery may never be observed. The overgrowth of opportunistic pathogens is of significant concern as they can lead to infections that become increasingly difficult to treat. Continued research to understand the disturbances within the gut microbiome of critically ill patients and their outcomes is essential to help develop future therapies to circumvent damage to, or restore, the microbiome. In this review, we discuss the impact of the antimicrobials often used for the treatment of sepsis on the gut microbiota.

Economics of Public Antibiotics Development

Issuing monetary incentives, such as market entry rewards, to stimulate private firm engagement has been championed as a solution to our urgent need for new antibiotics, but we ask whether it is economically rational to simply take public ownership of antibiotics development instead. We show that the cost of indirectly funding antibiotics development through late phase policy interventions, such as market entry rewards may actually be higher than simple direct funding. This result is reached by running a Monte Carlo simulation comparing the cost of increasing the ratio of investment go-decisions at the outset of pre-clinical development, to the cost of directly funding the same antibiotics under various levels of operational inefficiency. We simulate costs for hypothetical antibiotics targeting six different indications, using data from previous studies. We conclude that while indirect funding may be necessary for the current pipeline we may want to prefer direct funding as a cost effective long-term solution for future antibiotics.

Photo-inactivation of bacteria in hospital effluent via thiolated iron-doped nanoceria

Hospital wastewater is a major contributor of disease-causing microbes and the emergence of antibiotic resistant bacteria. In this study, thiolated iron-doped nanoceria was synthesised and tested for killing of microbes from hospital effluent. These particles were designed to inhibit the efflux pumps of the bacteria found in hospital effluent with further ability to activate in visible light via iron doping thus generating tunable amount of reactive oxygen species (ROS). The quantum yield of the ROS generated by the nanoceria was 0.67 while the ROS types produced were singlet oxygen (36%), hydroxyl radical (31%) and hydroxyl ions (32%), respectively. The particles were initially synthesised through green route using Foeniculum vulgare seeds extract and were annealed at 200°C and further coated with thiolated chitosan to enhance the solubility and efflux pump inhibition. X-ray diffraction confirmed the polycrystalline nature of nanoparticles and uniform spherical shape with 30 nm size, confirmed by scanning electron microscope. The nanoparticles exhibited 100% bactericidal activity at 100 µg/mL against all the isolated bacteria. The enhanced bactericidal effect of iron-doped nanoceria could be attributed to efflux inhibition via thiolated chitosan as well as the production of ROS upon illumination in visible light, causing oxidative stress against microbes found in hospital effluent.

Raman-activated sorting of antibiotic-resistant bacteria in human gut microbiota

The antibiotic‐resistant bacteria (ARB) and antibiotic‐resistant genes (ARGs) in human gut microbiota have significant impact on human health. While high throughput metagenomic sequencing reveals genotypes of microbial communities, the functionality, phenotype and heterogeneity of human gut microbiota are still elusive. In this study, we applied Raman microscopy and deuterium isotope probing (Raman–DIP) to detect metabolic active ARB (MA‐ARB) in situ at the single‐cell level in human gut microbiota from two healthy adults. We analysed the relative abundances of MA‐ARB under different concentrations of amoxicillin, cephalexin, tetracycline, florfenicol and vancomycin. To establish the link between phenotypes and genotypes of the MA‐ARB, Raman‐activated cell sorting (RACS) was used to sort MA‐ARB from human gut microbiota, and mini‐metagenomic DNA of the sorted bacteria was amplified, sequenced and analysed. The sorted MA‐ARB and their associated ARGs were identified. Our results suggest a strong relation between ARB in human gut microbiota and personal medical history. This study demonstrates that the toolkit of Raman–DIP, RACS and DNA sequencing can be useful to unravel both phenotypes and genotypes of ARB in human gut microbiota at the single‐cell level.

Agent-Based Modeling: A Method for Investigating Challenging Research Problems

BACKGROUND

For all our successes, many urgent health problems persist, and although some of these problems may be explored with established research methods, others remain uniquely challenging to investigate-maybe even impossible to study in the real world because of practical and pragmatic obstacles inherent to the nature of the research question.

OBJECTIVES

The purpose of this review article is to introduce agent-based modeling (ABM) and simulation and demonstrate its value and potential as a novel research method applied in nursing science.

METHODS

An introduction to ABM and simulation is described. Examples of current research literature on the subject are provided. A case study example of community nursing and opioid dependence is presented.

RESULTS

The use of ABM and simulation in human health research has increased dramatically over the past decade, and meaningful research is now commonly found published widely in respected, peer-reviewed journals. Absent from this list is innovative ABM and simulation research published by nurse researchers in nursing-specific journals.

DISCUSSION

ABM and simulation is a powerful method with tremendous potential in nursing research. It is vital that nursing embrace and adopt innovative and advanced research methods if we are to remain a progressive voice in health research, practice, and policy.

Antimicrobial and antibiofilm effects of abietic acid on cariogenic Streptococcus mutans

Dental caries is a type of oral microbiome dysbiosis and biofilm infection that affects oral and systemic conditions. For healthy life expectancy, natural bacteriostatic products are ideal for daily and lifetime use as anti-oral infection agents. This study aimed to evaluate the inhibitory effects of abietic acid, a diterpene derived from pine rosin, on the in vitro growth of cariogenic bacterial species, Streptococcus mutans. The effective minimum inhibitory concentration of abietic acid was determined through observation of S. mutans growth, acidification, and biofilm formation. The inhibitory effects of abietic acid on the bacterial membrane were investigated through the use of in situ viability analysis and scanning electron microscopic analysis. Cytotoxicity of abietic acid was also examined in the context of several human cell lines using tetrazolium reduction assay. Abietic acid was found to inhibit key bacterial growth hallmarks such as colony forming ability, adenosine triphosphate activity (both planktonic and biofilm), acid production, and biofilm formation. Abietic acid was identified as bacteriostatic, and this compound caused minimal damage to the bacterial membrane. This action was different from that of povidone-iodine or cetylpyridinium chloride. Additionally, abietic acid was significantly less cytotoxic compared to povidone-iodine, and it exerted lower toxicity towards epithelial cells and fibroblasts compared to that against monocytic cells. These data suggest that abietic acid may prove useful as an antibacterial and antibiofilm agent for controlling S. mutans infection.

A conceptual framework for the environmental surveillance of antibiotics and antibiotic resistance

Environmental surveillance of antibiotics and antibiotic resistance could contribute toward the protection of human, animal and ecosystem health. However, justification for the choice of markers and sampling sites that informs about different risk scenarios is often lacking. Here, we define five fundamentally different objectives for surveillance of antibiotics and antibiotic resistance in the environment. The first objective is (1) to address the risk of transmission of already antibiotic-resistant bacteria to humans via environmental routes. The second is (2) to address the risk for accelerating the evolution of antibiotic resistance in pathogens through pollution with selective agents and bacteria of human or animal origin. The third objective is (3) to address the risks antibiotics pose for aquatic and terrestrial ecosystem health, including the effects on ecosystem functions and services. The two final objectives overlap with those of traditional clinical surveillance, namely, to identify (4) the population-level resistance prevalence and (5) population-level antibiotic use. The latter two environmental surveillance objectives have particular potential in countries where traditional clinical surveillance data and antibiotic consumption data are scarce or absent. For each objective, the levels of evidence provided by different phenotypic and genotypic microbial surveillance markers, as well as antibiotic residues, are discussed and evaluated on a conceptual level. Furthermore, sites where monitoring would be particularly informative are identified. The proposed framework could be one of the starting points for guiding environmental monitoring and surveillance of antibiotics and antibiotic resistance on various spatiotemporal scales, as well as for harmonizing such activities with existing human and animal surveillance systems.

Trends and Drivers of Inpatient Antibiotic Consumption among 89 China Tertiary General Hospitals from 2011Q1 to 2015Q4

Antibacterial surveillance is an essential measure for strengthening the management of clinical antibiotic use. This study aimed to determine the trends and drivers of inpatient antibiotic consumption in China. A sample of 89 hospitals with complete data from 2011Q1 to 2015Q4 was included. Accumulative defined daily doses (DDDs), antibiotic use density (AUD), and drug variety were calculated to evaluate antibiotic consumption. From 2011Q1 to 2015Q4, the median values of DDDs, AUD, and drug variety dropped by 10.49%, 39.19%, and 27.96%, respectively. Panel regression results showed, for each additional quarter, DDDs reduced by 6.714 DDDs, AUD reduced by 0.013 DDDs per 100 inpatients per day, and drug variety reduced by 0.012 types (p < 0.001). National hospitals were more likely to use antibiotics, with the highest number of DDDs (106 709 DDDs) and AUD (60 DDDs per 100 inpatients per day) and a large number of drug variety (71 types of drug) all reported from national hospitals. Overall, a downward trend of inpatient antibiotic consumption was observed in competitive tertiary general hospitals in China. However, antibiotic use in China, especially in national hospitals, continues to exceed the guidelines set forth by the nationwide antibiotic stewardship program. China must continue to improve surveillance of antibiotic consumption by constructing a more comprehensive, continuous, and targeted stewardship program. Policy interventions in China should be made in consideration of unbalanced regional development and the consequences this may have on antibiotic consumption.

The Infinity War: How to Cope with Carbapenem-resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are now spread worldwide. In Korea, the number of CRE isolation is rapidly increasing, and impending endemicity is a concern. To cope well with CRE, thorough infection control, such as active surveillance, early detection, strict contact precaution, cleaning the environment, and antibiotic stewardship is very important. Therapeutic options include polymyxin, tigecycline, fosfomycin or the combination of them with carbapenem, which is currently the mainstay of treatment. In addition, various combination regimens with new carbapenemase inhibitors such as avibactam, vaborbactam, or relebactam, and other classes of antimicrobials such as plazomicin and siderophore cephalosporin are in the process of evaluation.