Microbial isolates and antibiotic sensitivity in patients hospitalized with odontogenic infections at a tertiary center over 10 years

Objectives

This study investigated causative strains and their antibiotic sensitivity in patients who were hospitalized for maxillofacial odontogenic infections at a tertiary center in South Korea over the past 10 years with the aim of providing guidelines for the selection of appropriate empirical antibiotics.

Materials and Methods

Patients with head and neck fascial space abscesses due to odontogenic infections who underwent incision and drainage surgery with pus culture tests between 2013 and 2022 at the Department of Oral and Maxillofacial Surgery, Dankook University Hospital were included. The bacterial isolates and antibiotic sensitivity of each strain were analyzed for 2013-2022, 2013-2017, and 2018-2022. The affected fascial spaces were classified into primary, secondary, and deep neck spaces.

Results

In the 192 patients included in this study, 302 strains were detected. Viridans streptococcus had the highest frequency (51.7%), followed by Prevotella spp. (16.9%), Staphylococcus spp. (5.6%), and Klebsiella pneumoniae (4.6%). The identification rate of viridans streptococcus significantly increased from 41.8% in 2013-2017 to 60.9% in 2018-2022. Viridans streptococcus showed an antibiotic sensitivity of 80.5% to ampicillin; the sensitivity to penicillin antibiotics decreased over the study period. Antibiotic susceptibility was approximately 94% for third-generation cephalosporins. K. pneumoniae, which was identified at a high percentage in patients with deep neck space infection, showed increasing antibiotic resistance to most antibiotics over the study period.

Conclusion

Viridans streptococcus was identified in head and neck fascial space abscesses with the highest frequency. Empirical antibiotics should be effective against this strain; penicillin antibiotics are considered inappropriate. For effective treatment of deep neck space abscesses, bacterial culture and antibiotic sensitivity tests performed as soon as possible are essential.

Review of knockout technology approaches in bacterial drug resistance research

Gene knockout is a widely used method in biology for investigating gene function. Several technologies are available for gene knockout, including zinc-finger nuclease technology (ZFN), suicide plasmid vector systems, transcription activator-like effector protein nuclease technology (TALEN), Red homologous recombination technology, CRISPR/Cas, and others. Of these, Red homologous recombination technology, CRISPR/Cas9 technology, and suicide plasmid vector systems have been the most extensively used for knocking out bacterial drug resistance genes. These three technologies have been shown to yield significant results in researching bacterial gene functions in numerous studies. This study provides an overview of current gene knockout methods that are effective for genetic drug resistance testing in bacteria. The study aims to serve as a reference for selecting appropriate techniques.

[New antibiotics for the treatment of urinary tract infections]

Urinary tract infections (UTIs) are among the most common bacterial infections. The clinical phenotypes of UTIs are heterogeneous, ranging from rather benign uncomplicated infections to complicated UTIs and pyelonephritis to severe urosepsis. Antibiotics have become indispensable in modern medicine, but the development of resistance is threatening clinical effectiveness. Antimicrobial resistance rates are locally high in UTIs, however can vary significantly depending on the population studied and the type of study. In addition, between 1990 and 2010, there was a discovery void in the development of new antibiotics that is still having an impact today. In recent years, UTIs have emerged as an infection model for research into novel antibiotics. In the last 10 years, novel gram-negative active drugs have been explored in these groups. On the one hand, novel beta-lactam/beta-lactamase inhibitor combinations were investigated, and there has also been further development of cephalosporins and aminoglycosides.

Outbreak investigations after identifying carbapenem-resistant Pseudomonas aeruginosa: a systematic review

BACKGROUND

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) are a serious cause of healthcare-associated infections. Part of the infection prevention and control measures are outbreak investigations (OI) of patients, healthcare workers (HCW), and the environment after identifying a CRPA in order to identify carriers and environmental reservoirs, so that targeted actions can be taken to prevent further transmission. However, little is known on when and how to perform such OI. Therefore, this systematic review aims to summarize OI performed after detection of CRPA in the endemic and epidemic hospital setting.

MAIN TEXT

Articles related to our research question were identified through a literature research in multiple databases (Embase, Medline Ovid, Cochrane, Scopus, Cinahl, Web of Science, and Google Scholar) until January 12, 2022 (Prospero registration number CRD42020194165). Hundred-twenty-six studies were included. In both the endemic and the epidemic setting, a median number of two out of seven predefined components of OI were identified. In the endemic setting, the most frequent component of OI was screening of the environment (28 studies, 62.2%). In the epidemic setting, screening of the environment (72 studies, 88.9%), and screening of patients during hospitalization (30 studies, 37%) were most frequently performed. Only 19 out of 126 studies (15.1%) reported screening of contact patients, and 37 studies reported screening of healthcare workers (HCW, 29.4%).

CONCLUSION

Due to probable underreporting of OI in the literature, the available evidence for the usefulness of the individual components of OI is scarce. This could lead to inhomogeneous performance of OI after detection of CRPA in the healthcare setting, and with this, potential under- or overscreening. While we could show evidence for the usefulness for environmental screening in order to identify the mode of transmission, evidence for HCW screening is scarce and might not lead to the identification of modes of transmission. Further studies are needed to better understand CI in different settings and, finally, develop guidance on when and how to best perform OI.

Eurasian griffon vultures carry widespread antimicrobial resistant Salmonella and Campylobacter of public health concern

The global emergence of antimicrobial-resistant (AMR) strains of Salmonella and Campylobacter is a serious public health concern. Both bacteria are leading causes of human gastrointestinal foodborne infections and the two most reported zoonoses in the European Union. By feeding on livestock carcasses, especially from intensive farming, as well as on landfill sites, obligate avian scavengers can become infected with zoonotic pathogens and AMR strains, and can be considered large-scale sentinels of the environmental burden. In this study, we assessed the occurrence and AMR of Salmonella spp. and Campylobacter spp. in 218 Eurasian griffon vultures (Gyps fulvus) captured in north-eastern Spain. We isolated Salmonella from 8.1 % of individuals and Campylobacter lari from 4.7 %. Among the 10 different Salmonella serovars found, monophasic S. Typhimurium was the most frequent. Genotyping analysis revealed same strains of monophasic S. Typhimurium shared by gulls, livestock and humans. Isolates from both bacterial species presented AMR to important antimicrobials (tetracyclines, fluoroquinolones and β-lactams). In conclusion, this study shows that Eurasian griffon vultures in north-eastern Spain are carriers of widespread AMR zoonotic Salmonella and Campylobacter. More comprehensive analyses are still needed to understand the potential risk of spill-over from those wild birds to humans.

Antibiotic resistance among bacteria isolated from war-wounded patients at the Weapon Traumatology Training Center of the International Committee of the Red Cross from 2016 to 2019: a secondary analysis of WHONET surveillance data

Background

A substantial body of evidence has recently emphasized the risks associated with antibiotic resistance (ABR) in conflicts in the Middle East. War-related, and more specifically weapon-related wounds can be an important breeding ground for multidrug resistant (MDR) organisms. However, the majority of available evidence comes from the military literature focused on risks and patterns of ABR in infections from combat-related injuries among military personnel. The overall aim of this study is to contribute to the scarce existing evidence on the burden of ABR among patients, including civilians with war-related wounds in the Middle East, in order to help inform the revision of empirical antibiotic prophylaxis and treatment protocols adopted in these settings. The primary objectives of this study are to: 1) describe the microbiology and the corresponding resistance profiles of the clinically relevant bacteria most commonly isolated from skin, soft tissue and bone biopsies in patients admitted to the WTTC; and 2) describe the association of the identified bacteria and corresponding resistance profiles with sociodemographic and specimen characteristics.

Methods

We retrospectively evaluated the antibiograms of all consecutive, non-duplicate isolates from samples taken from patients admitted to the ICRC WTTC between 2016 and 2019, limited to skin and soft tissue samples and bone biopsies. We collected data on socio-demographic characteristics from patient files and data on specimens from the WHONET database. We ran univariate and multivariable logistic regression models to test the association between bacterial and resistance profiles with sociodemographic and specimen characteristics.

Results

Patients who were admitted with war-related trauma to the ICRC reconstructive surgical project in Tripoli, Lebanon, from 2016 to 2019, presented with high proportion of MDR in the samples taken from skin and soft tissues and bones, particularly Enterobacterales (44.6%), MRSA (44.6%) and P. aeruginosa (7.6%). The multivariable analysis shows that the odds of MDR isolates were higher in Iraqi patients (compared to Syrian patients) and in Enterobacterales isolates (compared to S. aureus isolates).

Conclusions

Our findings stress the importance of regularly screening patients who present with complex war-related injuries for colonization with MDR bacteria, and of ensuring an antibiotic-sensitivity testing-guided antimicrobial therapeutic approach.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07253-1.

A Retrospective, Longitudinal External Study of the robustness and reproducibility of National Antibacterial Prescribing Survey Data

BACKGROUND

Point prevalence surveys are used internationally to audit antibacterial use as well as the impact of interventions on improving prescribing and resistance rates. The annual National Antibacterial Prescribing Survey provides data on the appropriateness of antibacterial agent prescribing in Australian hospitals. Assessing the survey's robustness and result reproducibility is essential to its role in improving antibacterial prescribing practice.

AIM

To evaluate the reproducibility of internal assessments of antibacterial agent prescribing of both guideline compliance and appropriateness from a Western Australian hospital.

METHOD

Census data of 1051 prescriptions from 2013 to 2017 surveys were independently assessed for compliance based on Australian Therapeutic Guidelines - Antibiotics, and appropriateness, based on agent selection, therapy duration and microbiological test results. Concordance of these findings with internal hospital assessments was analysed.

RESULTS

This external study did not reproduce internal hospital audit results for compliance with guideline parameters. Non-compliant prescribing rate was significantly (p < 0.001) higher externally at 50.7% (533/1051) than internal assessment at 34.9% (367/1051). External analysis also found a significantly smaller proportion of prescriptions to be appropriate (551/1051, 52.4%) compared to internal analysis (745/1051, 70.9%) p < 0.001. Cohen's Kappa analysis found a moderate agreement for compliance (0.49) and appropriateness (0.50) between the external and internal evaluations.

CONCLUSION

The lack of adequate reproducibility of compliance and appropriateness assessments may limit the generalisability of the audit's results. Validating point prevalence surveys that assess antibacterial agent prescribing can increase confidence and improve reproducibility of their findings; as they provide important data for antimicrobial stewardship programs.

Efficacy and safety of daptomycin in Japanese pediatric participants with complicated skin and soft tissue infections or bacteremia caused by gram-positive cocci

INTRODUCTION

Complicated skin and soft tissue infections (cSSTIs) and bacteremia caused by Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), are common causes of infection for children worldwide. Here, the safety and efficacy of daptomycin in Japanese pediatric participants are reported.

METHODS

This open-label, single-arm phase 2 study (NCT03643952) enrolled Japanese pediatric participants (age 1-17 years) with cSSTI or bacteremia caused by gram-positive cocci. Participants received age-adjusted doses of intravenous daptomycin for 5 to up to 14 days (cSSTI) or 5 to up to 42 days (bacteremia). The primary objective was safety and tolerability; efficacy among participants with infections caused by MRSA was a secondary objective.

RESULTS

A total of 18 participants (cSSTI, n = 14; bacteremia, n = 4) were enrolled across 12 study sites in Japan. The most common pathogen was S. aureus (15/18 [83.3%]), including methicillin-susceptible and -resistant isolates. Adverse events (AE) were reported in 42.9% (6/14) of participants with cSSTI and 100% (4/4) of participants with bacteremia. No deaths, serious AEs, discontinuations of study medication due to an AE, or events of clinical interest occurred in the study. In participants with infections caused by MRSA, 87.5% [7/8] achieved favorable clinical response at test of cure (TOC) visit (cSSTI, 85.7% [6/7]; bacteremia, 100% [1/1]). In this population, favorable microbiological response at TOC was achieved by 71.4% (5/7) of participants with cSSTI and 100% (1/1) of participants with bacteremia.

CONCLUSIONS

Daptomycin was well tolerated, exhibited a favorable safety profile, and was effective for the treatment of cSSTI or bacteremia in Japanese children.

Rapid identification of the resistance of urinary tract pathogenic bacteria using deep learning-based spectroscopic analysis

The resistance of urinary tract pathogenic bacteria to various antibiotics is increasing, which requires the rapid detection of infectious pathogens for accurate and timely antibiotic treatment. Here, we propose a rapid diagnosis strategy for the antibiotic resistance of bacteria in urinary tract infections (UTIs) based on surface-enhanced Raman scattering (SERS) using a positively charged gold nanoparticle planar solid SERS substrate. Then, an intelligent identification model for SERS spectra based on the deep learning technique is constructed to realize the rapid, ultrasensitive, and non-labeled detection of pathogenic bacteria. A total of 54,000 SERS spectra were collected from 18 isolates belonging to 6 species of common UTI bacteria in this work to realize identification of bacterial species, antibiotic sensitivity, and multidrug resistance (MDR) via convolutional neural networks (CNN). This method significantly simplify the Raman data processing processes without background removing and smoothing, however, achieving 96% above classification accuracy, which was significantly greater than the 85% accuracy of the traditional multivariate statistical analysis algorithm principal component analysis combined with the K-nearest neighbor (PCA-KNN). This work clearly elucidated the potential of combining SERS and deep learning technique to realize culture-free identification of pathogenic bacteria and their associated antibiotic sensitivity.

Repositioning of non-antibiotic drugs as an alternative to microbial resistance: a systematic review

The global spread of microbial resistance coupled with high costs and slow pace in the discovery of a new antibiotic have made drug repositioning an attractive and promising alternative in the treatment of infections caused by multidrug resistant (MDR) microorganisms. The reuse involves the production of compounds with lower costs and development time, using diversified production technologies. The present systematic review aimed to present a selection of studies published in the last 20 years, which report the antimicrobial activity of non-antibiotic drugs that are candidates for repositioning, which could be used against the current microbial multidrug resistance. A search was performed in the PubMed, SciELO and Google Scholar databases using the following search strategies: [(drug repurposing) OR (drug repositioning) OR (repositioning) AND (non-antibiotic) AND (antibacterial activity) AND (antimicrobial activity)]. Overall, 112 articles were included, which explored the antimicrobial activity in antidepressants, antihypertensives, anti-inflammatories, antineoplastics, hypoglycemic agents, among other drugs. It was concluded that they have significant antimicrobial activity in vitro and in vivo, against standard strain and clinical isolates (Gram-negative and Gram-positive) and fungi. When associated with antibacterials, most of these drugs had their antibacterial activity enhanced. It was also a consensus of the studies included in this review that the presence of aromatic rings in the molecular structure contributes to antimicrobial activity. This review highlights the potential repositioning of several classes of non-antibiotic drugs as promising candidates for repositioning in the treatment of severe bacterial infections of MDR bacteria, extensively resistant (XDR) and pan-resistant (PDR) to drugs.

Infections and antimicrobial resistance in intensive care units in lower-middle income countries: a scoping review

Background

Intensive care units (ICUs) in lower-middle income countries (LMICs) are suspected to constitute a special risk for patients of acquiring infection due to multiple antibiotic resistant organisms. The aim of this systematic scoping review was to present the data published on ICU-acquired infections and on antimicrobial resistance observed in ICUs in LMICs over a 13-year period. A systematic scoping review was conducted according to the PRISMA extension guideline for scoping reviews and registered in the Open Science Framework.

Main body of the abstract

Articles were sought that reported on ICU-acquired infection in LMICs between 2005 and 2018. Two reviewers parallelly reviewed 1961 titles and abstracts retrieved from five data banks, found 274 eligible and finally included 51. Most LMICs had not produced reports in Q1 or Q2 journals in this period, constituting a large gap in knowledge. However, from the reported evidence it is clear that the rate of ICU-acquired infections was comparable, albeit approximately 10% higher, in LMICs compared to high income countries. In contrast, ICU mortality was much higher in LMICs (33.6%) than in high income countries (< 20%). Multidrug-resistant Gram-negative species, especially Acinetobacter baumannii and Pseudomonas aeruginosa, and Klebsiella pneumoniae played a much more dominant role in LMIC ICUs than in those in high income countries. However, interventions to improve this situation have been shown to be feasible and effective, even cost-effective.

Conclusions

Compared to high income countries the burden of ICU-acquired infection is higher in LMICs, as is the level of antimicrobial resistance; the pathogen distribution is also different. However, there is evidence that interventions are feasible and may be quite effective in these settings.

Protocol Registration The protocol was registered with Open Science Framework (https://osf.io/c8vjk)

[Antibiotic therapy in Bielefeld (AnTiB)-a local project for the promotion of rational antibiotic prescribing in the outpatient pediatric sector]

BACKGROUND

Antimicrobial resistance is an increasing problem - a consequence of uncritical use, especially of "last-resort" antibiotics. Approaches towards a more rational use of antibiotics have so far focused on the inpatient sector, whereas the majority of antibiotics are prescribed in the outpatient sector. Therefore, there is demand for innovative approaches for the latter sector. The project Antibiotic Therapy in Bielefeld ("AnTiB"), founded in 2016 by pediatricians active in the outpatient pediatric sector, developed respective structures and measures at the local level.

OBJECTIVES

The development of local recommendations, suitable for everyday practice, for antibiotic prescription in frequent infectious conditions, are described.

MATERIALS AND METHODS

In order to develop these recommendations, evidence from the literature and practice guidelines was collected. In a structured process, mainly via quality circles, the contents were consented locally and then put under external expert review. Together with the Association of Statutory Health Insurance Physicians of Westphalia-Lippe (KVWL), antibiotic prescription data were collected exemplarily for 2016.

RESULTS

The first version of the respective pediatric recommendations was published in January 2017. Meanwhile, comparable recommendations for outpatient gynecologists and adult GPs were released. Antibiotic prescription data from 2016 show an important spread of antibiotic prescription prevalences in general as well as with respect to single agent classes.

CONCLUSIONS

Locally consented practical recommendations may contribute to a local "culture" of antibiotic prescription behavior. The pediatric recommendations locally have so far gained good coverage and high acceptance. Transfer to other regions or medical disciplines seems possible and reasonable. In the future, the effects of such projects on the prescription behavior will be measurable by the comparison of prescription data.

Use of ceragenins as a potential treatment for urinary tract infections

BACKGROUND

Urinary tract infections (UTIs) are one of the most common bacterial infections. High recurrence rates and the increasing antibiotic resistance among uropathogens constitute a large social and economic problem in current public health. We assumed that combination of treatment that includes the administration ceragenins (CSAs), will reinforce the effect of antimicrobial LL-37 peptide continuously produced by urinary tract epithelial cells. Such treatment might be an innovative approach to enhance innate antibacterial activity against multidrug-resistant E. coli.

METHODS

Antibacterial activity measured using killing assays. Biofilm formation was assessed using crystal violet staining. Viability of bacteria and bladder epithelial cells subjected to incubation with tested agents was determined using MTT assays. We investigated the effects of chosen molecules, both alone and in combinations against four clinical strains of E. coli, obtained from patients diagnosed with recurrent UTI.

RESULTS

We observed that the LL-37 peptide, whose concentration increases at sites of urinary infection, exerts increased bactericidal effect against E. coli when combined with ceragenins CSA-13 and CSA-131.

CONCLUSION

We suggest that the employment of combination of natural peptide LL-37 with synthetic analogs might be a potential solution to treat urinary tract infections caused by drug-resistant bacteria.

Detection of antibiotic resistance is essential for gonorrhoea point-of-care testing: a mathematical modelling study

BACKGROUND

Antibiotic resistance is threatening to make gonorrhoea untreatable. Point-of-care (POC) tests that detect resistance promise individually tailored treatment, but might lead to more treatment and higher levels of resistance. We investigate the impact of POC tests on antibiotic-resistant gonorrhoea.

METHODS

We used data about the prevalence and incidence of gonorrhoea in men who have sex with men (MSM) and heterosexual men and women (HMW) to calibrate a mathematical gonorrhoea transmission model. With this model, we simulated four clinical pathways for the diagnosis and treatment of gonorrhoea: POC test with (POC+R) and without (POC-R) resistance detection, culture and nucleic acid amplification tests (NAATs). We calculated the proportion of resistant infections and cases averted after 5 years, and compared how fast resistant infections spread in the populations.

RESULTS

The proportion of resistant infections after 30 years is lowest for POC+R (median MSM: 0.18%, HMW: 0.12%), and increases for culture (MSM: 1.19%, HMW: 0.13%), NAAT (MSM: 100%, HMW: 99.27%), and POC-R (MSM: 100%, HMW: 99.73%). Per 100 000 persons, NAAT leads to 36 366 (median MSM) and 1228 (median HMW) observed cases after 5 years. Compared with NAAT, POC+R averts more cases after 5 years (median MSM: 3353, HMW: 118). POC tests that detect resistance with intermediate sensitivity slow down resistance spread more than NAAT. POC tests with very high sensitivity for the detection of resistance are needed to slow down resistance spread more than by using culture.

CONCLUSIONS

POC with high sensitivity to detect antibiotic resistance can keep gonorrhoea treatable longer than culture or NAAT. POC tests without reliable resistance detection should not be introduced because they can accelerate the spread of antibiotic-resistant gonorrhoea.

Investigation and control of a suspected nosocomial outbreak of pan-drug resistant Acinetobacter baumannii in an intensive care unit

Acinetobacter baumannii, a non-fermenting Gram-negative bacterium, is a common pathogen in intensive care units (ICU) that is easily spread through contact and can cause nosocomial outbreaks. This study investigated the risk factors associated with outbreaks of pan-drug resistant Acinetobacter baumannii (PDR-Ab) infection by studying a suspected nosocomial outbreak in a comprehensive ICU in a teaching hospital in China, and discusses the effectiveness of current prevention and control measures. Pathogen detection methods involving pulsed field gel electrophoresis (PFGE) were employed to survey patients infected or colonized with PDR-Ab. An epidemiological investigation was conducted to determine the risk factors for infection or colonization with PDR-Ab between 1 October 2014 and 16 January 2015. The rate of PDR-Ab infection in the ICU was higher during the period from 1 October 2014 to 16 January 2015 than it was between 1 October 2013 and 16 January 2014. Only two cases were confirmed to have the same genotype. Risk factors were explored and the rate of infection was found to be controlled by interventions targeting these risk factors. A decrease in the number of infections was observed after multiple prevention and control measures were implemented, preventing the outbreak of a nosocomial infection.

Antibiotic Control Policies in South Korea, 2000-2013

Antibiotic stewardship is a key strategy for limiting antibiotic resistance. Over the last decade the South Korean government has implemented a series of healthcare policies directed to this end, consisting of legislative separation of drug prescribing and dispensing, antibiotic utilization reviews, healthcare quality assessment, and public reporting. As a result, the proportion of antibiotic prescriptions for acute upper respiratory tract infections in primary healthcare facilities decreased from 72.9% in 2002 to 42.7% in 2013. However, no significant decrease in antibiotic resistance occurred over the same period in clinically important bacteria such as Streptococcus pneumoniae. These government-driven policies played a pivotal role in improving antibiotic use for outpatients and surgical patients in South Korea. However, to achieve long-lasting successful outcomes, coordinated efforts and communications among the stakeholders, including physicians and medical societies, are needed.