Effective Antimicrobial Therapy Research Articles

Antimicrobial susceptibility of enterobacterales causing bloodstream infection in United States medical centres: comparison of aztreonam-avibactam with beta-lactams active against carbapenem-resistant enterobacterales

BackgroundBloodstream infection (BSI) is associated with poor outcomes especially when effective antimicrobial therapy and control of infection source are delayed. As the frequency of Enterobacterales producing metallo-β-lactamases (MBL) and/or OXA-48–like carbapenemases is increasing in some United States (US) medical centres, effective antimicrobials to treat the infections caused by these organisms are urgently needed. Aztreonam-avibactam is under clinical development for treatment of infections caused by Gram-negative bacteria, including MBL producers.ObjectivesTo evaluate the antimicrobial susceptibility of Enterobacterales causing BSI in US medical centres and compare the activity of aztreonam-avibactam with ceftazidime-avibactam, meropenem-vaborbactam, imipenem-relebactam, cefiderocol, and other antimicrobials used to treat BSI.Methods4,802 Enterobacterales were consecutively collected (1/patient) from 72 US medical centres in 2020–2022 and susceptibility tested by broth microdilution. Aztreonam-avibactam was tested with avibactam at a fixed concentration of 4 mg/L. A pharmacokinetic/pharmacodynamic susceptible breakpoint of ≤ 8 mg/L was applied for aztreonam-avibactam for comparison. Carbapenem-resistant Enterobacterales (CRE) isolates were tested for β-lactamase–encoding genes using Next-generation sequencing.ResultsAztreonam-avibactam was highly active against Enterobacterales; only 2 isolates showed aztreonam-avibactam MICs > 8 mg/L: 1 meropenem-susceptible E. coli and 1 K. aerogenes (CRE). All carbapenemase producers and 98.0% of CRE were inhibited at an aztreonam-avibactam MIC of ≤ 8 mg/L. CRE susceptibility rates were 81.6% for ceftazidime-avibactam, 65.3% for meropenem-vaborbactam, 61.2% for imipenem-relebactam, and 87.8% for cefiderocol. Aztreonam-avibactam retained activity (MIC, ≤ 8 mg/L) against all (100.0%) meropenem-vaborbactam nonsusceptible (n = 17), 99.5% of imipenem-relebactam nonsusceptible (n = 206), and 90.0% of ceftazidime-avibactam nonsusceptible (n = 10) isolates. The most common carbapenemases were KPC-2/3 (57.1% of CREs), OXA-48–like (16.3%), and NDM (14.3%). A carbapenemase gene was not observed in 12.3% of CREs. Ceftazidime-avibactam and meropenem-vaborbactam were active against 100.0% of KPC producers, but ceftazidime-avibactam showed limited activity against MBL producers and meropenem-vaborbactam showed limited activity against OXA-48–like and MBL producers. The most active non–β-lactam comparators against CRE were gentamicin (49.0% susceptible) and amikacin (44.9% susceptible).ConclusionsAztreonam-avibactam demonstrated potent activity against a large collection of Enterobacterales isolated from patients with BSI in US hospitals, including CRE, MBL producers, and isolates resistant to recently approved β-lactamase inhibitor combinations.

The Time Course of Catecholamine Dose Reduction in Septic Shock as a Predictor of Bacterial Susceptibility to Empiric Antimicrobial Therapy: A Retrospective Observational Study.

Background/Objectives: The 28-day mortality rate for septic shock is high, necessitating rapid and effective empiric antimicrobial therapy. In this study, we investigate whether the rate of catecholamine dose reduction in septic shock can indicate bacterial susceptibility to initial antimicrobial therapy or not. Methods: This retrospective observational study involved 108 adult patients with bacteraemia and septic shock admitted to the intensive care unit of Nihon University Itabashi Hospital between January 2017 and December 2023. They were classified into the Susceptible or Resistant groups based on the bacteria's susceptibility to the initial empiric antimicrobial therapy. Catecholamine dosages were converted to norepinephrine equivalent (NEE) scores, with the time course from the peak to the end of administration measured at NEE reductions. Results: Of the 108 patients, 94 were in the Susceptible group and 14 in the Resistant group. The Susceptible group showed faster reductions in catecholamine doses: the time to reduce the dose from the maximum NEE to 25% was 19 vs. 49.5 h (p = 0.0057), and to 0%, it was 29 vs. 54 h (p = 0.0475). The time to reduce the dose from the maximum NEE to 75% was 8 vs. 12.5 h (p = 0.0733), and to 50% it was 13 vs. 21.5 h (p = 0.1081). Conclusions: In septic shock with bacteraemia, a faster catecholamine dose reduction indicates bacterial susceptibility to the initial empiric antibiotics. This reduction rate can serve as an early clinical indicator of the appropriate initial empiric therapy.

EVALUATION OF THE ROLE OF SELECTIVE DIGESTIVE TRACT DECONTAMINATION IN PREVENTION OF VENTILATOR ASSOCIATED PNEUMONIA IN INTENSIVE CARE UNIT PATIENTS

Ventilator-associated pneumonia (VAP) is a significant nosocomial infection in critically ill patients, contributing to increased morbidity, mortality, and healthcare costs. The incidence of VAP in intensive care units (ICUs) ranges from 7% to 40%, with mortality rates potentially exceeding 50%1. Recent studies highlight that VAP affects approximately 27% of all critically ill patients, with 86% of these infections associated with mechanical ventilation. The attributable mortality of VAP varies, with some studies reporting an increase in mortality of up to 27%3. Pathogens such as Pseudomonas aeruginosa, Acinetobacter, and Stenotrophomonas maltophilia are linked to higher mortality rates4. Beyond mortality, VAP significantly extends ICU length of stay and increases healthcare costs5. The gastrointestinal tract plays a crucial role in VAP pathogenesis, as it often becomes colonized with Gram-negative bacteria during critical illness6. Interventions such as selective decontamination of the digestive tract (SDD), stress ulcer prophylaxis with sucralfate, and enteral feeding strategies are employed to reduce VAP incidence. While SDD has been shown to decrease VAP incidence and may positively impact mortality, it also poses a risk of promoting Gram-positive bacterial infections. SDD involves the use of non-absorbable antibiotics applied topically to the oropharynx and through a nasogastric tube, often supplemented with systemic antibiotics during the initial days of ICU admission. Recent guidelines and systematic reviews continue to emphasize the importance of accurate VAP diagnosis and effective antimicrobial therapy to improve patient outcomes and reduce healthcare burdens.

Immunomodulatory activity of omadacycline in vitro and in a murine model of acute lung injury.

Cystic fibrosis (CF) is characterized by chronic airway obstruction, infection, and inflammation leading to progressive loss of lung function and eventual respiratory failure. Omadacycline, a tetracycline antibiotic, demonstrates in vitro activity against key CF pathogens, substantial lung penetration, and increasing clinical evidence for the treatment of lung infections in people with CF (PwCF). Preliminary in vitro data demonstrate that omadacycline exhibits anti-inflammatory activity. This study aims to determine the anti-inflammatory effects of omadacycline in vitro and in a murine model of lipopolysaccharide (LPS)-induced lung neutrophilia. In vitro, THP-1-derived macrophages were treated with omadacycline (20-100 µg/mL) 30 minutes prior to LPS stimulation. Pro-inflammatory cytokine (TNF-α, IL-1β/6), chemokine (CXCL-1/2), and MMP-9 levels were analyzed after 24 hours by ELISA. Omadacycline's effects on IL-8-induced human neutrophil chemotaxis were also investigated. In vivo, omadacycline (2.5-30 mg/kg), comparators dexamethasone (1 mg/kg), and azithromycin (30 mg/kg) were administered 1 hour before and 6 hours after intranasal LPS challenge, respectively. Leukocyte counts and differentials in bronchoalveolar lavage fluid (BALF), inflammatory mediator levels in BALF and lung homogenates, pulmonary edema markers, and the severity of lung injury were evaluated 24 hours or 48 hours post-challenge. Treatment with omadacycline in vitro resulted in significant, dose-dependent reductions in IL-6, CXCL-1, and MMP-9 expression and inhibition of IL-8-induced neutrophil chemotaxis. In vivo, omadacycline yielded protective and therapeutic effects by reducing the production of proinflammatory cytokines and chemokines and neutrophil infiltration into the lungs, along with modestly improving lung injury severity. These preclinical results suggest that omadacycline may provide dual anti-bacterial and anti-inflammatory activities relevant to chronic lung infection treatment in PwCF.IMPORTANCENontuberculous mycobacteria, particularly Mycobacterium abscessus complex (MABSC), are a major concern for people with cystic fibrosis (PwCF) due to their association with deteriorating lung function. A substantial barrier to effective treatment is the limited number of safe and effective antibiotics. Omadacycline offers a potential advancement in managing MABSC infections in cystic fibrosis due to its activity, effective penetration into pulmonary secretions, improved tolerability, and good oral bioavailability as shown in healthy volunteers. Our study is the first to explore omadacycline's effects in a model of sterile lung inflammation and acute lung injury. We found that omadacycline not only has potent anti-bacterial properties but also exhibits anti-inflammatory effects, reducing lung inflammation and injury in our preclinical models. These findings underscore omadacycline's potential as a dual-action therapy for lung infections in PwCF, indicating significant potential to improve patient outcomes and guide more effective antimicrobial therapy decisions.

Antibacterial Therapy and Prevention of Infectious Endocarditis in Modern Conditions

The problem of infectious endocarditis (IE) still retains its importance due to high mortality rates and the development of severe complications. Modern IE is a polyethological disease, the occurrence and development of which can be caused by pathogens that make up an extremely extensive list, which is updated almost annually. At the same time, serious obstacles standing in the way of effective antimicrobial therapy are both the increasing resistance of IE pathogens to antibiotics and the increasing etiological role of infectious agents that were previously very rare. This article presents the basic principles of treatment and prevention of IE, taking into account the latest recommendations of the experts of the European Society of Cardiology in 2023.

Establishment of a platform based on dual RPA combined with CRISPR/Cas12a for the detection of Klebsiella pneumoniae and its KPC resistance gene.

Carbapenem resistant Klebsiella pneumoniae (CRKP) can cause serious hospital- and community-acquired infections. Treatment for CRKP infection is limited, resulting in prolonged hospitalization and high consultation costs. The KPC genotype has the highest detection rate of CRKP, and its mortality rate is higher than the overall mortality rate of CRKP. However, traditional testing methods have disadvantages such as long time and reliance on complex and sophisticated instruments, which are not conducive to rapid screening for CRKP. Therefore, this study aimed to establish a detection platform for early screening of CRKP so that effective antimicrobial therapy could be administered promptly to prevent the widespread spread of CRKP. We integrated dual RPA with CRISPR/Cas12a to establish a dual platform for the detection of K. pneumoniae (Kp) rcsA-specific gene and KPC resistance gene. Four result reading methods were established, including fluorescence detection (FD), blue light irradiation detection (BLID), ultraviolet irradiation detection (UID), and lateral flow test strips (LFTS). For the rcsA gene, the LOD of FD was 1 × 10pg/μL, and the other three methods could detect 1 × 101pg/μL of bacterial DNA. As for the KPC gene, four resultant readout methods were able to detect 1 × 102pg/μL of bacterial DNA. In 59 clinical strains tested, the dual RPA-CRISPR/Cas12a detection of the rcsA had 100% sensitivity, specificity, and accuracy compared to the culture method. Compared with the drug sensitivity test, the sensitivity of dual RPA-CRISPR/Cas12a detection for the KPC was 85.71%, the specificity was 100%, and the accuracy was 94.92%. In summary, our dual RPA-CRISPR/Cas12a platform proved to be rapid, precise, and convenient for the efficient detection of Kp with KPC in the laboratory or at the point of care.

Impact of direct identification of bacteria in blood culture–positive specimens by matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry on physician selection of antimicrobial therapy

BackgroundRapid identification of the causative organism in blood stream infections is essential for early initiation of appropriate antimicrobial therapy. Direct identification of bacteria in positive blood culture bottles using matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry is a promising application. A variety of direct identification methods have been reported; however, few studies have evaluated the impact of these methods on physician decision making regarding antimicrobial therapy. MethodsWe developed a simple method for direct bacterial identification and applied it to daily clinical practice to investigate the impact of direct identification of bacteria in positive blood culture bottles on physicians’ choice of antimicrobial agents for treatment. ResultsFrom January 2016 to December 2022, we attempted direct identification in 98 cases and successfully acquired identification results in 88 cases. In three cases, no empiric antimicrobial agents were initiated at the time of venipuncture for blood culture but later initiated based on the direct identification results. In the remaining 85 cases, empiric antimicrobial therapy was initiated at the time blood cultures were performed, and in 29 cases, empiric antimicrobial therapy was changed after direct identification. In 17 of these 29 cases, the antimicrobial therapy was changed based on the direct identification of bacterial genus/species, resulting in a change to an effective antimicrobial therapy before the antimicrobial susceptibility testing results were available. ConclusionsDirect identification of bacteria from positive blood culture bottles could contribute to earlier selection of or changes to antimicrobial therapies by attending physicians.

Fighting A New Front On An Old Battlefield: Examining the Development of Topical Antimicrobial Care to Control Burn Wound Sepsis.

Recognition of invasive burn wound sepsis as a major cause of morbidity and mortality in burn injured patients has profoundly changed the management of burn wounds and its associated complications. The development of effective topical antimicrobial therapy is one of the last major developments of modern burn care and has been driven by major world events and scientific breakthroughs. Topical antimicrobial burn care has evolved from the use of anecdotal remedies to scientific breakthroughs such as Moyer's successful dilution of silver nitrate solution, Fox's described benefit of silver sulfadiazine use in animal models, and Pruitt's dramatic improvement in post-burn mortality using topical mafenide acetate in burn wounds. The objective of this manuscript is to review the definition of burn wound sepsis and highlight the major developments and breakthroughs in topical burn wound care throughout history. This includes historical events like major wars or domestic fires that have influenced or impacted the understanding and treatment of burn wounds. Newer advances in topical antimicrobial care such as nanosilvers and dressing technologies that improve the morbidity and mortality associated with burn wound sepsis and novel approaches to management will also be discussed. To improve burn care, it is prudent to look to the past and learn from the experiences of those who contributed to the control of burn wound sepsis.

Third Kuwaiti Multicenter Survey of Antibiotic Susceptibility of Anaerobic Bacteria: A Comparative Analysis of 20-Year Data.

Objective: This study aimed to evaluate antibiotic susceptibility and antimicrobial resistance trends among clinically significant anaerobes in Kuwait hospitals from 2013 to 2022, comparing these findings with data from 2002 to 2012. Methods: The study prospectively collected 2,317 anaerobic isolates from various body sites across four Kuwaiti hospitals between January 2013 and December 2022. The minimum inhibitory concentrations for 11 antianaerobic antibiotics were determined using E-test methodology. The study analyzed trends and resistance rates across two periods: 2013-2017 and 2018-2022, using statistical analysis for resistance comparison. Results: Of the 2,317 isolates, most were from wounds (42.2%), fluids (28.0%), and tissues (20.5%). Bacteroides fragilis was the most common pathogen (34.0%), followed by Prevotella bivia (13.4%). Over 90% of isolates were susceptible to imipenem, meropenem, tigecycline, and metronidazole, whereas lower susceptibility was observed for penicillin, amoxicillin-clavulanic acid, and clindamycin. Notable differences in resistance profiles since 2002 were observed, especially in amoxicillin-clavulanic acid, piperacillin, piperacillin-tazobactam, and clindamycin. Conclusion: Owing to detected resistance to all antibiotics, susceptibility testing for anaerobic isolates is recommended in severe infections to ensure effective antimicrobial therapy. Continuous surveillance is crucial for developing antibiotic policies to manage invasive anaerobic infections.

Fe-doped herbal medicine-based carbon dots nanozyme as safe and effective antimicrobial and wound healing agent

Bacterial infections pose a serious worldwide public health concern and play an important role in slowing or dramatically delaying wound healing. However, traditional antibiotics are faced with obstacles such as bacterial resistance and unsatisfactory biocompatibility, which has impeded further clinical translation. In recent years, antimicrobial nanomaterials have emerged as viable alternatives for combating bacterial infections, and carbon dots (CDs) have received particularly widespread attention due to their superior characteristics. In this work, a simple and eco-friendly one-step hydrothermal method was employed using the natural herbal medicine Eucommia ulmoides as a biomass carbon source to synthesize an Fe-doped CDs nanozyme (Fe-CDs) with good peroxidase-like (POD-like) activity, high biocompatibility, and strong antimicrobial activity for safe and effective antimicrobial therapy and the promotion of wound healing. L929 cells co-cultured with Fe-CDs did not show significant cytotoxicity and favored cell proliferation at appropriate concentrations. In addition, Fe-CDs catalyzed the decomposition of low-concentration H2O2 to ·OH, leading to enhanced antimicrobial activity. Both in vitro and in vivo experiments demonstrated that Fe-CDs exhibit potent antibacterial properties, the ability to promote cell migration and angiogenesis, and significant potential for promoting the healing of infected wounds. In summary, a green and safe antimicrobial nanozyme based on a biomass herbal medicine was developed in this work, offering promising insight into the development of novel antimicrobial materials and tissue regeneration engineering.

Late-onset sepsis in newborns caused by Bacillus Cereus: a case report and literature review

Bacillus cereus is a bacterium capable of causing late-onset neonatal sepsis. By analyzing 11 cases, this study investigates the diagnosis, treatment, and prognosis of Bacillus cereus infections, aiming to provide insights into clinical diagnosis and therapy. The study scrutinized 11 instances of late-onset neonatal sepsis, including two fatalities attributable to Bacillus cereus, one accompanied by cerebral hemorrhage. An examination and analysis of these cases’ symptoms, signs, laboratory tests, and treatment processes, along with a review of related literature from 2010 to 2020, revealed a high mortality rate of 41.38% in non-gastrointestinal infections caused by Bacillus cereus. Our findings underscore the critical importance of rapid diagnosis and effective antimicrobial therapy in reducing mortality rates. Once the source of infection is identified, implementing effective infection control measures is essential.

Rapid Classification and Differentiation of Sepsis-Related Pathogens Using FT-IR Spectroscopy.

Sepsis is a life-threatening condition arising from a dysregulated host immune response to infection, leading to a substantial global health burden. The accurate identification of bacterial pathogens in sepsis is essential for guiding effective antimicrobial therapy and optimising patient outcomes. Traditional culture-based bacterial typing methods present inherent limitations, necessitating the exploration of alternative diagnostic approaches. This study reports the successful application of Fourier-transform infrared (FT-IR) spectroscopy in combination with chemometrics as a potent tool for the classification and discrimination of microbial species and strains, primarily sourced from individuals with invasive infections. These samples were obtained from various children with suspected sepsis infections with bacteria and fungi originating at different sites. We conducted a comprehensive analysis utilising 212 isolates from 14 distinct genera, comprising 202 bacterial and 10 fungal isolates. With the spectral analysis taking several weeks, we present the incorporation of quality control samples to mitigate potential variations that may arise between different sample plates, especially when dealing with a large sample size. The results demonstrated a remarkable consistency in clustering patterns among 14 genera when subjected to principal component analysis (PCA). Particularly, Candida, a fungal genus, was distinctly recovered away from bacterial samples. Principal component discriminant function analysis (PC-DFA) allowed for distinct discrimination between different bacterial groups, particularly Gram-negative and Gram-positive bacteria. Clear differentiation was also observed between coagulase-negative staphylococci (CNS) and Staphylococcus aureus isolates, while methicillin-resistant S. aureus (MRSA) was also separated from methicillin-susceptible S. aureus (MSSA) isolates. Furthermore, highly accurate discrimination was achieved between Enterococcus and vancomycin-resistant enterococci isolates with 98.4% accuracy using partial least squares-discriminant analysis. The study also demonstrates the specificity of FT-IR, as it effectively discriminates between individual isolates of Streptococcus and Candida at their respective species levels. The findings of this study establish a strong groundwork for the broader implementation of FT-IR and chemometrics in clinical and microbiological applications. The potential of these techniques for enhanced microbial classification holds significant promise in the diagnosis and management of invasive bacterial infections, thereby contributing to improved patient outcomes.

A case of recurrent peritoneal dialysis-related peritonitis caused by Stenotrophomonas maltophilia during ongoing antibiotic treatment for Enterococcus faecalis-induced peritonitis.

Recurrent peritonitis is a serious complication of peritoneal dialysis (PD), which could result in PD withdrawal and mortality. However, cases of recurrent peritonitis occurring during ongoing antimicrobial therapy are rarely reported. Herein, we present a 71-year-old man who experienced initial peritonitis due to Enterococcus faecalis. Despite effective antimicrobial therapy, he developed recurrent peritonitis while on antimicrobial therapy. PD fluid culture analysis yielded Stenotrophomonas maltophilia (S. maltophilia). He was treated with multiple antimicrobials, and the peritoneal catheter was removed. To the best of our knowledge, this is the first case of recurrent peritonitis caused by S. maltophilia, which was developed during antimicrobial treatment. Our report findings suggest the importance of considering S. maltophilia infection in an atypical case of very early recurrent peritonitis.

Exploring Microbiological Quality Assessment Techniques and Antibiotic Sensitivity: A Comprehensive Review

Microbiological quality assessment and antibiotic sensitivity testing are crucial components of ensuring public health safety, food quality, and effective antimicrobial therapy and provides a comprehensive overview of the methodologies, challenges, and recent advancements in microbiological quality assessment and antibiotic sensitivity testing. It covers various techniques employed in microbiological quality assessment, including culture-based methods, molecular techniques, and rapid detection methods. Additionally, it explores the principles and methodologies of antibiotic sensitivity testing, focusing on disk diffusion, broth microdilution, and automated systems. Furthermore, the article discusses emerging trends and technologies in the field, such as whole-genome sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and understanding these techniques and their applications is essential for researchers, healthcare professionals, and policymakers to combat microbial infections effectively and safeguard public health.

Whole genome sequencing of uropathogenic E. coli from Ireland reveals diverse resistance mechanisms and strong correlation with phenotypic (EUCAST) susceptibility testing

Urinary tract infections (UTI) caused by uropathogenic Escherichia coli (UPEC) pose a global health concern. Resistance mechanisms, including genetic mutations in antimicrobial target genes, efflux pumps, and drug deactivating enzymes, hinder clinical treatment. These resistance factors often spread through mobile genetic elements. Molecular techniques like whole genome sequencing (WGS), multilocus sequence typing (MLST), and phylotyping help decode bacterial genomes and categorise resistance genes.In this study, we analysed 57 UPEC isolates from different UTI patients following EUCAST guidelines. A selection of 17 representative strains underwent WGS, phylotyping, MLST, and comparative analysis to connect laboratory susceptibility data with predictive genomics based on key resistance genes and chromosomal mutations in antimicrobial targets.Trimethoprim resistance consistently correlated with dfr genes, with six different alleles detected among the isolates. These dfr genes often coexisted with class 1 integrons, with the most common gene cassette combining dfr and aadA. Furthermore, 52.9% of isolates harboured the blaTem-1 gene, rendering resistance to ampicillin and amoxicillin. Ciprofloxacin-resistant strains exhibited mutations in GyrA, GyrB and ParC, plasmid-mediated quinolone resistance genes (qnrb10), and aac(6′)-Ib-cr5. Nitrofurantoin resistance in one isolate stemmed from a four amino acid deletion in NfsB.These findings illustrate the varied strategies employed by UPEC to resist antibiotics and the correlation between clinical susceptibility testing and molecular determinants. As molecular testing gains prominence in clinical applications, understanding key resistance determinants becomes crucial for accurate susceptibility testing and guiding effective antimicrobial therapy.

Treatment planning for photodynamic therapy of abscess cavities using patient-specific optical properties measured prior to illumination

Photodynamic therapy (PDT) is an effective antimicrobial therapy that we used to treat human abscess cavities in a Phase 1 clinical trial. This trial included pre-PDT measurements of abscess optical properties, which affect light dose (light fluence) at the abscess wall and PDT response. This study simulated PDT treatment planning for 13 subjects that received optical spectroscopy prior to clinical PDT, to determine the impact of measured optical properties on ability to achieve fluence rate targets in 95% of the abscess wall. Retrospective treatment plans were evaluated for 3 conditions: (1) clinically delivered laser power and assumed, homogeneous optical properties, (2) clinically delivered laser power and measured, homogeneous optical properties, and (3) with patient-specific treatment planning using measured, homogeneous optical properties. Treatment plans modified delivered laser power, intra-cavity Intralipid (scatterer) concentration, and laser fiber type. Using flat-cleaved laser fibers, the proportion of subjects achieving 95% abscess wall coverage decreased significantly relative to assumed optical properties when using measured values for 4 mW cm−2 (92% versus 38%, p = 0.01) and 20 mW cm−2 (62% versus 15%, p = 0.04) thresholds. When measured optical properties were incorporated into treatment planning, the 4 mW cm−2 target was achieved for all cases. After treatment planning, optimal Intralipid concentration across subjects was 0.14 ± 0.09%, whereas 1% was used clinically. Required laser power to achieve the 4 mW cm−2 target was significantly correlated with measured abscess wall absorption (ρ = 0.7, p = 0.008), but not abscess surface area (ρ = 0.2, p = 0.53). When using spherical diffuser fibers for illumination, both optimal Intralipid concentration (p = 0.0005) and required laser power (p = 0.0002) decreased compared to flat cleaved fibers. At 0% Intralipid concentration, the 4 mW cm−2 target could only be achieved for 69% of subjects for flat-cleaved fibers, compared to 100% for spherical diffusers. Based on large inter-subject variations in optical properties, individualized treatment planning is essential for abscess photodynamic therapy. (Clinical Trial Registration: The parent clinical trial from which these data were acquired is registered on ClinicalTrials.gov as ‘Safety and Feasibility Study of Methylene Blue Photodynamic Therapy to Sterilize Deep Tissue Abscess Cavities,’ with ClinicalTrials.gov identifier NCT02240498).

Extended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae: Risk Factors and Economic Burden Among Patients with Bloodstream Infections.

Although Extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EK) significantly contribute to bloodstream infections, their economic repercussions remain largely unquantified. We performed a retrospective analysis of inpatients diagnosed with Escherichia coli or Klebsiella pneumoniae bacteremia in a tertiary hospital from January 2020 to December 2022 in Guangzhou, China. We employed the chi-square test to examine ESBL risk factors and utilized propensity score matching (PSM) to negate baseline confounding factors, assessing economic burden through disability-adjusted life years (DALYs), hospital costs and productivity losses. We employed mediation analysis to eliminate confounding factors and better identify ESBL sources of burden related. We found 166 ESBL-EC/KP BSI patients (52.2% of the total examined 318 patients). Post-PSM analysis revealed that ESBL-producing EC/KP will reduce the effectiveness of empirical medication by 19.8%, extend the total length of hospitalization by an average of 3 days, and increase the patient's financial burden by US$2047. No significant disparity was found in overall mortality and mean DALYs between the groups. Mediation analysis showed that the link between ESBL and hospital costs is predominantly, if not entirely, influenced by the appropriateness of empirical antibiotic treatment and length of hospital stay. Patients with BSI due to ESBL-producing ESBL-EK incur higher costs compared to those with non-ESBL-EK BSI. This cost disparity is rooted in varying rates of effective empirical antimicrobial therapy and differences in hospital stay durations. A nuanced approach, incorporating a thorough understanding of regional epidemiological trends and judicious antibiotic use, is crucial for mitigating the financial impact on patients.

Evaluation of the Types and Drug Sensitivity Patterns of Bacterial Isolates from Patients with Eye Discharge at Abia State University Teaching Hospital, Aba, Nigeria

This study aimed to evaluate the types and drug sensitivity patterns of bacterial isolates from patients with eye discharge at the Abia State University Teaching Hospital (ABSUTH), Aba, Nigeria. A total of 100 samples were collected, with the most prevalent bacterial isolates being Staphylococcus aureus (26%) and Coagulase-negative Staphylococci (21%), while no bacterial growth was reported in 42% of samples. In terms of patient demographics, a significant proportion of the patients were females (64%) aged between 61-70 years. In relation to contact lens use, a high percentage (97%) of the bacterial isolates were detected in patients who did not use contact lenses. An occupational distribution analysis revealed that bacterial isolates were more frequent in farmers and traders compared to students and retirees. Antimicrobial sensitivity testing of the bacterial isolates showed varying degrees of resistance, with significant resistance observed against Erythromycin, Ciprofloxacin, and Perfloxacin. In contrast, higher sensitivity was noted towards Chloramphenicol and Gentamycin. The findings underscore the importance of regular microbiological evaluation and sensitivity testing in patients presenting with eye discharges to guide effective antimicrobial therapy. These findings could guide the selection of empiric antibiotics for treating ocular infections in this region and suggest the need for routine microbiological surveillance to monitor and guide antibiotic prescription to mitigate against antibiotic resistance.

Устойчивость к противомикробным препаратам и роль пробиотиков в ее преодолении

The concept of risk management and the ideology of microbiocenosis-oriented therapy can be one of the simple and understandable approaches to the formation of modern ideas about the possibilities of integrated use of antibiotics and probiotics as components of effective antimicrobial therapy. In addition to traditional bacterial probiotics, Saccharomyces boulardii CNCM I-745, which has a number of advantages for the realization of such a therapy strategy, are widely used in real practice. The affiliation of S. boulardii CNCM I-745 to fungi makes it possible to use them in any regimen of complex therapy, including antibacterial drugs. This approach improves treatment compliance, ultimate efficacy of therapy and reduces the likelihood of adverse drug reactions. S. boulardii CNCM I-745 are able to reduce the number of genes encoding antimicrobial resistance (ARG) by modulating the intestinal microbiota and controlling the number of bacteria actively forming the pool of ARG, activation of the immune system, which allows to implement antimicrobial effects against pathogens at early stages of the infectious process, production of saturated fatty acids that have antimicrobial properties and have synergistic effects with other antimicrobial drugs. Key words: antibiotic, antimicrobial resistance, resistome, Saccharomyces boulardii, mycobiome

Salmonella contamination in raw chicken meat in Kabul city: Occurrence and antibiotic resistance patterns

Objective: Food-borne illnesses pose a significant risk to public health on a global scale and are a major contributing factor to illness and death rates worldwide. Salmonella strains found in chicken meat and its related products may be the likely source of a multi-country outbreak. Research is scarce regarding the occurrence of antimicrobial-resistant Salmonella in chicken meat within Afghanistan; therefore, in the present study, the aim was to identify Salmonella found in uncooked chicken meat in the local markets of Kabul city and ascertain their susceptibility to commonly used antibiotics. Materials and Methods: One hundred raw chicken meats were gathered from four districts of Kabul city from May 2022 until April 2023; the isolates were then identified using culture, biochemical tests, and the analytical profile index; an examination of antimicrobial susceptibility was conducted utilizing the disk diffusion technique. Results: Out of 100 samples, only 8 (8%) tested positive for Salmonella spp. The disk diffusion results from Salmonella-positive samples showed multidrug resistance; maximum resistance was against ampicillin (100%) followed by norfloxacin (75%), nalidixic acid (62.5%), cefoxitin (62.5%), tetracycline, and ciprofloxacin (50%). Conclusion: The global occurrence of foodborne infections and antibiotic resistance has increased and preserved public health concerns around the world. Identifying zoonotic bacteria and their antimicrobial resistance patterns is critical for controlling their transmission and facilitating effective antimicrobial therapy in both humans and animals.