Effective Antimicrobial Treatment Research Articles

Targeted antimicrobial regimens for Gram-negative prosthetic joint infections: a prospective multicenter study.

Fluoroquinolones (FQs) are considered the most effective antimicrobial treatment for Gram-negative prosthetic joint infection (GN-PJI). Alternatives are needed due to increasing FQ resistance and side effects. We aimed to compare different targeted antimicrobial strategies for GN-PJI managed by debridement, antibiotics, and implant retention (DAIR) or one-stage revision surgery (1SR) and to review the literature of oral treatment options for GN-PJI. In this prospective, multicenter, registry-based study, all consecutive patients with a PJI caused by a Gram-negative microorganism (including mixed infections with Gram-positive microorganisms), managed with DAIR or 1SR from 2015 to 2020, were included. Minimum follow-up was 1 year. Patients underwent targeted therapy with oral FQ, oral cotrimoxazole, or intravenous or oral β-lactams. Survival analysis was performed with use of Kaplan-Meier and Cox proportional hazards models to identify factors potentially associated with treatment failure. Seventy-four patients who received either FQ (n = 47, 64%), cotrimoxazole (n = 13, 18%), or β-lactams (n = 14, 18%) were included. Surgical strategy consisted of DAIR (n = 72) or 1SR (n = 2). Median follow-up was 449 days (interquartile range 89-738 days). Failure free survival did not differ between the FQ (72%) and cotrimoxazole (92%) groups (log rank, P = 0.13). This outcome did not change when excluding all pseudomonal PJI in the FQ group. Cotrimoxazole is a potential effective targeted antimicrobial therapy for patients with GN-PJI. A randomized controlled trial is needed to confirm the findings of this study.

Microbial Trends and their Drug Resistance Responsible for Bloodstream Infections in a Superspeciality Transplant Hospital

Background & Objective: Bloodstream infections (BSIs) are critical healthcare-associated infections that lead to high morbidity and mortality, requiring rapid diagnosis and effective antimicrobial treatment. The increasing prevalence of multidrug-resistant organisms (MDROs) exacerbates this issue, particularly in developing countries. The purpose of this study is to assess the bacteriological profile and antimicrobial susceptibility trends of BSIs to establish an antibiogram for effective empirical treatment. Materials and Methods: This study was conducted retrospectively on 3,300 blood culture samples from a multispecialty hospital over 15 months. Cultures were performed using Bactec FX and identification and antibiotic susceptibility determined by Vitek2 and Kirby-Bauer methods following CLSI guidelines. Results: Overall, the positivity rate was (14.3%) with 473 isolates: (400 bacterial and 73 fungal). Gram-negative bacteria were predominant, led by Klebsiella pneumoniae (113 isolates) and Escherichia coli (100 isolates). Among the Gram-negative bacteria, antimicrobial susceptibility was found to be low for Cephalosporins (21%sensitivity) and Fluoroquinolones (19.3% sensitivity), with moderate susceptibility to Carbapenems (51.3%). Sensitivity was high for Colistin (98.9%), Amikacin (91.05%), Tigecycline (100%), Fosfomycin (100%) and Ceftazidime-avibactum Aztreonam (97.7%). Among Gram-positive bacteria, Coagulase-negative Staphylococcal Species (CONS) and Staphylococcus aureus were the most common. The overall sensitivity of Gram-positive bacteria to antibiotics tested was high compared to the Gram-negative bacteria. Sensitivity to antibiotics such as Linezolid was found to be 94.5% and Vancomycin was found to be 93.5%. Conclusion: The high incidence of MDROs especially among the Gram-negative bacteria highlights the need for continuous monitoring and antibiotic stewardship programs. Empirical therapy must consider local resistance patterns, and a multidisciplinary approach is essential to mitigate antimicrobial resistance.

A comparative study of a rapid phenotypic antimicrobial susceptibility testing system directly from positive blood cultures to the disk diffusion and VITEK 2 methods

BackgroundSepsis is a life-threatening condition that impacts 49 million people annually and causes 11 million deaths worldwide. Surviving bloodstream infections (BSIs) depends on the rapid administration of effective antimicrobial treatment, underscoring a need for rapid antimicrobial susceptibility testing (AST). AimTo evaluate the performance of Quantamatrix's dRAST v2.5 system (Seoul, South Korea) for AST directly from positive blood cultures as compared to the Disk-Diffusion (DD) and VITEK 2 methods. MethodsThe study included 191 positive blood cultures from clinical samples and spiked blood culture bottles. Following Gram staining and species-level identification, AST was performed by VITEK 2 and standard DD methods using CLSI (2021) interpretation. ResultsdRAST demonstrated very good AST performance for a Gram-negative isolate, and good performance for Gram-positive isolates, meeting CLSI criteria for the acceptance of a new method. Antimicrobials that were not considered verified compared to VITEK 2 and DD were cefazolin, ceftazidime, meropenem, and trimethoprim/sulfamethoxazole for Gram-negatives and clindamycin, erythromycin, penicillin, and oxacillin for Gram-positives. dRAST ESBL detection results were strongly correlated with the ESBL phenotypes obtained with other methods. Additional resistance mechanisms were in concordance with traditional tests. ConclusionsdRAST demonstrated good AST performance, meeting CLSI criteria for most relevant antibiotics. dRAST was associated with a significant reduction in time-to-results, labor, and the subjectivity of result analyses, making it a valuable addition to efforts supporting the treatment of patients with bacteremia.AST (antimicrobial susceptibility test), blood culture, dRAST, rapid methods, sepsis, turnaround time (TAT).

Mini Review: Antimicrobial Agents Based on Natural Compounds: The Key to Solving the Current Crisis

Context: The rapid development of resistance mechanisms by bacteria has led to the loss of effectiveness of many commonly used antibiotics, posing a serious threat to global public health. Therefore, the objective of this study is to provide further insights into combating antibiotic resistance and addressing the urgent need for additional effective antimicrobial treatments as alternatives. Methods: In this narrative review, natural compounds derived from plants, fungi, and other sources were evaluated for their antimicrobial properties based on clinical trials and in vitro studies. These compounds have gained attention due to their potential to serve as alternative or adjunctive therapies. Results: We briefly reviewed and introduced antibacterial agents derived from natural substances and extracts as an alternative solution to the current crisis. Many natural sources, such as antimicrobial peptides (AMPs), nanoparticles, enzyme disruption of acylhomoserine lactones (AHLs), Mur enzymes, lysocine E, plant-derived natural products, polyphenols, nanozymes, antimicrobial peptidomimetics, and antimicrobials of fungal origin (such as penicillin, griseofulvin, amphotericin B, echinocandins, and statins), produce a wide range of secondary metabolites with the potential to exhibit antibacterial activity. Moreover, natural products often possess complex chemical structures, which can target multiple bacterial pathways, enhancing their ability to inhibit or kill bacteria. Conclusions: This study contributes new knowledge and perspectives on combating antibiotic resistance by exploring alternative treatments and natural products, which represent an important area of research. It may offer new solutions to address the urgent need for effective antimicrobial treatments. Further research is necessary to isolate, identify, and characterize the active compounds, study their mechanisms of action, optimize their efficacy and safety, and evaluate their potential for clinical use.

Sonodynamic inactivation of gram-negative and gram-positive bacteria in the presence of phenothiazine compounds toluidine blue and azurin A

BackgroundSonodynamic antimicrobial chemotherapy (SACT) is an effective antimicrobial treatment that can avoid the production of drug-resistant bacteria. Design and development of new high-efficiency sonosensitizers play a key role in the practical application of SACT. MethodsThe bacteriostatic effects of two phenothiazine compounds, toluidine blue (TB) and azure A (AA) combined with ultrasonic (US) on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were studied, and the sonodynamic antibacterial activities of TB and AA were compared. The reactive oxygen species (ROS) and the types of ROS produced in the sonodynamic system were detected and the sonodynamic mechanisms of TB and AA were proposed. ResultsThe sonodynamic bacteriostasis mediated by TB and AA increased with the increasing concentration of sonosensitizer, the extension of sonication time and the increase of reaction temperature. The production of ROS was the main reason that TB and AA had excellent sonodynamic antibacterial performance. Singlet oxygen (1O2) and hydroxyl radical (•OH) were the main ROS types in the sonodynamic antibacterial system. The ROS produced by the combined action of AA and US was higher than that of TB. ConclusionBoth TB and AA displayed excellent sonodynamic antibacterial activities. Moreover, AA had a higher sonodynamic activity than TB. The electron donation effect and steric hindrance effect of the methyl group of phenothiazine parent nucleus of TB might be the cause of the decrease of its sonodynamic activity. These results would provide a valuable reference for the further study of phenothiazines sonosensitizers and their clinical application in SACT.

Comparison of the Results of BAL and ETA Culture in Intubated COVID-19 Patients.

The isolation of pathogens using bronchoalveolar lavage (BAL) culture or endotracheal aspirate (ETA) culture may enhance the treatment success for secondary pneumonia due to COVID-19, thereby reducing the risk of morbidity and mortality. This study aimed to retrospectively analyze the results of BAL and ETA cultures in intubated COVID-19 patients and to determine whether BAL has an advantage over ETA. We routinely perform BAL culture via bronchoscopy or ETA culture within the first 48 h after intubation. We retrospectively reviewed cases that underwent BAL and ETA. The patients were divided into two groups: Group B (BAL) and Group E (ETA). Various parameters were evaluated and compared between the two groups. The demographic data and blood test results were similar between the two groups. However, ICU stay, duration of intubation, and culture positivity were significantly higher in Group B. Although not statistically significant, the mortality rate was higher in Group E. The most commonly isolated microorganisms were Candida species. The observed mortality rates were consistent with the existing literature. Since the microorganism isolation rate is higher with BAL, leading to more effective antimicrobial treatment, early deaths were prevented, and ICU stay durations were prolonged. Conversely, these durations were shorter in the ETA group due to higher mortality. In intubated COVID-19 patients, a more effective treatment process can be achieved by clearing the airway with fiberoptic bronchoscopy and tailoring the treatment based on BAL culture results. This approach may positively impact prognosis and mortality rates.

Intracranial dissemination of Klebsiella pneumoniae originating from pulmonary infection: a case report

BackgroundMetastatic brain abscesses caused by Klebsiella pneumoniae are extremely rare but life-threatening conditions. To depict a unique case of the middle-aged hypertensive man with an unusual presentation of metastatic brain abscesses originating from a pleural abscess caused by Klebsiella pneumoniae and subsequently leading to loss of consciousness (LOC).Case reportA 52-year-old Iranian man with a history of hypertension presented to the emergency department with a five-day history of worsening cough, high-grade fever, shortness of breath, chest pain, fatigue, and a productive cough. Laboratory tests revealed leukocytosis, elevated C-reactive protein, and respiratory alkalosis. A chest computed tomography scan confirmed pneumonia, and a brain scan revealed multiple hypodense lesions. Despite antibiotic therapy, the patient's condition worsened, leading to confusion, disorientation, and loss of consciousness. Magnetic resonance imaging revealed multiple ring-enhancing lesions, suggesting an abscess formation. Bronchial washings and BAL samples confirmed a lower respiratory tract infection. Cultures from the bronchial washings grew Klebsiella pneumoniae.ConclusionsMetastatic brain abscesses caused by Klebsiella pneumoniae are exceedingly rare but life-threatening conditions. Timely diagnosis and effective antimicrobial treatment are critical for patient outcomes. This case underscores the significance of recognizing atypical presentations of bacterial infections, as early detection and appropriate management can significantly impact patient outcomes.

Anti-Microbial, Thermal, Mechanical, and Gas Barrier Properties of Linear Low-Density Polyethylene Extrusion Blow-Molded Bottles.

Microbial contamination can occur on the surfaces of blow-molded bottles, necessitating the development and application of effective anti-microbial treatments to mitigate the hazards associated with microbial growth. In this study, new methods of incorporating anti-microbial particles into linear low-density polyethylene (LLDPE) extrusion blow-molded bottles were developed. The anti-microbial particles were thermally embossed on the external surface of the bottle through two particle deposition approaches (spray and powder) over the mold cavity. The produced bottles were studied for their thermal, mechanical, gas barrier, and anti-microbial properties. Both deposition approaches indicated a significant enhancement in anti-microbial activity, as well as barrier properties, while maintaining thermal and mechanical performance. Considering both the effect of anti-microbial agents and variations in tensile bar weight and thickness, the statistical analysis of the mechanical properties showed that applying the anti-microbial agents had no significant influence on the tensile properties of the blow-molded bottles. The external fixation of the particles over the surface of the bottles would result in optimum anti-microbial activity, making it a cost-effective solution compared to conventional compounding processing.

Clinical Utility of Follow-Up Blood Cultures Among Adult Cancer Patients with Gram-Negative Bacilli Bacteremia

Background: Gram-negative bacilli (GNB) bacteremia is a common and potentially fatal infection with mortality rates estimated to be 14-34%, despite effective antimicrobial treatments. Follow-up blood cultures (FUBCs) are blood cultures that are repeated after an initial positive culture and are indicated in certain clinical scenarios, such as in candidemia or Staphylococcus aureus bacteremia to ensure clearance of the bloodstream infection. FUBCs are used in bacteremia to assess the appropriateness and duration of antimicrobial therapy. Currently, there are no guidelines in place regarding the use of FUBC for GNB bacteremia. Furthermore, the utility of FUBCs is not well-studied in adults living with cancer. The purpose of this study is to identify risk factors associated with persistent GNB bacteremia in adult patients with cancer. Methods: We conducted a single-center, retrospective study in patients aged ≥18 years, hospitalized during calendar year 2022, living with cancer, and with laboratory confirmed GNB bloodstream infection. FUBC was defined as a blood culture performed within 7 days of the initial positive blood culture. Patients were grouped as having the same organism on FUBC (+/same), FUBC with no growth (NG) (+/NG), and different organism on FUBC (+/Different). Patients with a different organism on FUBC were excluded from analysis. We gathered demographic information, suspected source of bacteremia, type of malignancy, identified organisms, presence of antimicrobial resistance, and comorbidities (eg. presence of central venous catheters, urinary catheters, end-stage renal disease). Categorical variables were compared using Chi-square or Fisher’s exact test. Continuous variables were compared using Wilcoxon rank sum tests. Logistic regression analysis was used to identify the independent predictors of persistent GNB bacteremia. Results: 356 unique patients with FUBC were identified after inclusion/exclusion criteria. 93/356 (26%) of patients had persistent GNB bacteremia (+/same). Multivariate analysis identified history of bacteremia within the preceding year (OR 2.95, 95% CI [1.6-5.6]) and Achromobacter spp. bacteremia (OR 10.03, 95% CI [1.59-63.23] as independent risk factors for persistence. Organisms with multidrug resistance such as extended-spectrum beta-lactamase (OR 2.47, 95% CI [1.21-5.07]) and carbapenem-resistant organisms (OR 3.35, 95% CI [1.04-10.81]) were also associated with persistent GNB bacteremia. Conclusions: This is the first study to specifically identify risk factors for persistent GNB bacteremia in patients living with cancer. FUBC may be useful in GNB bacteremia with less common organisms and/or if they exhibit multidrug resistance on susceptibility testing. The utility of FUBC should be further explored in patients with cancer with certain risk factors.

Antibiotic Resistance Pattern of Bacteria Isolated from Clinical Specimens: A Hospital-Based Cross-sectional Study in Kathmandu, Nepal

Antibiotics are vital in combating infectious diseases, yet their increasing use fosters resistance. Antimicrobial resistance (AMR) is rising in Nepal due to factors such as indiscriminate, inappropriate, and inadequate antibiotic usage. This study aims to explore the association between demographic factors and the prevalence of specific bacterial strains within the surveyed population. Additionally, it seeks to determine the antibiotic resistance patterns of these bacteria. Antibiotic susceptibility or resistance data were retrieved from the Medical Records Department (MRD) of the Manmohan Memorial Medical College and Teaching Hospital (MMMCTH) in Kathmandu. Samples from patients with certain types of bacterial infections were included, with 56 from sputum reports, 46 from urine, and 8 from blood samples out of 110 retrieved. Analysis revealed that sputum samples were mostly from older males, while urine samples were mostly from females. Yet, gender did not significantly influence bacterial presence across sample types. Overall, Escherichia coli was the most prevalent bacterium (74%), followed by Salmonella typhi (25%), Staphylococcus aureus (25%), and Klebsiella pneumoniae (23%) isolated from different type of clinical samples. Altogether, 6-15 antibiotics were assessed for sensitivity, with 2–6 antibiotics showing sensitivity to blood bacteria, 1-6 antibiotics demonstrating sensitivity to sputum bacteria, and 3–8 antibiotics exhibiting sensitivity to urine bacteria. Many investigated antibiotics were resistant, only gentamicin exhibited sensitivity for all types of bacteria found in blood, sputum and urine. These findings underscore the importance of discerning bacterial resistance patterns for effective antimicrobial treatment selection.

KHÁNG KHÁNG SINH CỦA Streptococcus agalactiae GÂY BỆNH TRÊN CÁ RÔ PHI (Oreochromis sp.) Ở MIỀN BẮC VIỆT NAM

Antimicrobial resistance (AMR) is a threat to animal and human health globally. Antimicrobials are used in aquaculture to control different bacterial diseases. However, inappropriate use of antimicrobials can accelerate the emergence of AMR. This study was conducted to determine antimicrobial resistance in Streptococcus agalactiae, which affects and causes diseases with high mortality in tilapia. A total of 26 S. agalactiae isolates were streaked from kidney/brain/liver samples of diseased farmed tilapia from 2017 to 2021 at Hai Duong, Bac Ninh, Hoa Binh, Yen Bai provinces. The sensitivity of the isolates to 7 antimicrobials was established by disc diffusion (Oxiod). The results showed that levels of resistance vary from S. agalactiae to DOX (34.4%), RIF (64.1%), TET (45.0%), ERY (64.8%), TMPSMX (70%), FLO (35.3%), and AMP (75%). The resistance rate to DOX was significantly different (p<0.05) compared to ERY. S. agalactiae has the highest resistance to 2 types of antibiotics at 19.2%, followed by resistance to 3 types (15.4%), and resistance to 6 and 7 types of antibiotics at a rate of 11.5%. The resistance in 1 type, 4 types, and 5 types of antibiotics was observed lowest at 7.7%. Vietnamese tilapia farmers need guidelines for effective antimicrobial treatment and wwider take up of vaccine or sustainable farming technology to prevent infections caused by S. agalactiae and reduce emergence of AMR

Genetic basis of clarithromycin resistance in Bacillus anthracis.

The high-consequence pathogen Bacillus anthracis causes human anthrax and often results in lethal infections without the rapid administration of effective antimicrobial treatment. Antimicrobial resistance profiling is therefore critical to inform post-exposure prophylaxis and treatment decisions, especially during emergencies such as outbreaks or where intentional release is suspected. Whole-genome sequencing using a rapid long-read sequencer can uncover antimicrobial resistance patterns if genetic markers of resistance are known. To identify genomic markers associated with antimicrobial resistance, we isolated B. anthracis derived from the avirulent Sterne strain with elevated minimal inhibitory concentrations to clarithromycin. Mutants were characterized both phenotypically through broth microdilution susceptibility testing and observations during culturing, as well as genotypically with whole-genome sequencing. We identified two different in-frame insertions in the L22 ribosomal protein-encoding gene rplV, which were subsequently confirmed to be involved in clarithromycin resistance through the reversion of the mutant gene to the parent (drug-susceptible) sequence. Detection of the rplV insertions was possible with rapid long-read sequencing, with a time-to-answer within 3 h. The mutations associated with clarithromycin resistance described here will be used in conjunction with known genetic markers of resistance for other antimicrobials to strengthen the prediction of antimicrobial resistance in B. anthracis.IMPORTANCEThe disease anthrax, caused by the pathogen Bacillus anthracis, is extremely deadly if not treated quickly and appropriately. Clarithromycin is an antibiotic recommended for the treatment and post-exposure prophylaxis of anthrax by the Centers for Disease Control and Prevention; however, little is known about the ability of B. anthracis to develop resistance to clarithromycin or the mechanism of that resistance. The characterization of clarithromycin-resistant isolates presented here provides valuable information for researchers and clinicians in the event of a release of the resistant strain. Additionally, knowledge of the genetic basis of resistance provides a foundation for susceptibility prediction through rapid genome sequencing to inform timely treatment decisions.

The association between Dioscorea sansibarensis and Orrella dioscoreae as a model for hereditary leaf symbiosis.

Hereditary, or vertically-transmitted, symbioses affect a large number of animal species and some plants. The precise mechanisms underlying transmission of functions of these associations are often difficult to describe, due to the difficulty in separating the symbiotic partners. This is especially the case for plant-bacteria hereditary symbioses, which lack experimentally tractable model systems. Here, we demonstrate the potential of the leaf symbiosis between the wild yam Dioscorea sansibarensis and the bacterium Orrella dioscoreae (O. dioscoreae) as a model system for hereditary symbiosis. O. dioscoreae is easy to grow and genetically manipulate, which is unusual for hereditary symbionts. These properties allowed us to design an effective antimicrobial treatment to rid plants of bacteria and generate whole aposymbiotic plants, which can later be re-inoculated with bacterial cultures. Aposymbiotic plants did not differ morphologically from symbiotic plants and the leaf forerunner tip containing the symbiotic glands formed normally even in the absence of bacteria, but microscopic differences between symbiotic and aposymbiotic glands highlight the influence of bacteria on the development of trichomes and secretion of mucilage. This is to our knowledge the first leaf symbiosis where both host and symbiont can be grown separately and where the symbiont can be genetically altered and reintroduced to the host.

Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia.

In Ethiopia, milk production and handling practices often lack proper hygiene measures, leading to the potential contamination of milk and milk products with Staphylococcus aureus (S. aureus), including methicillin-resistant strains,posing significant public health concerns. This study aimed to investigate the occurrence, antimicrobial susceptibility profiles and presence of resistance genes in S. aureus strains isolated from milk and milk products. A cross-sectional study was conducted in the Arsi highlands, Oromia, Ethiopia from March 2022 to February 2023. A total of 503 milk and milk product samples were collected, comprising 259 raw milk, 219 cottage cheese, and 25 traditional yogurt samples. S. aureus isolation and coagulase-positive staphylococci enumeration were performed using Baird-Parker agar supplemented with tellurite and egg yolk. S. aureus was further characterized based on colony morphology, Gram stain, mannitol fermentation, catalase test, and coagulase test. Phenotypic antimicrobial resistance was assessed using the Kirby-Bauer disc diffusion method, while the polymerase chain reaction (PCR) was employed for confirming the presence of S. aureus and detecting antimicrobial resistance genes. S. aureus was detected in 24.9% of the milk and milk products, with the highest occurrence in raw milk (40.9%), followed by yogurt (20%), and cottage cheese (6.4%). The geometric mean for coagulase-positive staphylococci counts in raw milk, yogurt, and cottage cheese was 4.6, 3.8, and 3.2 log10 CFU/mL, respectively. Antimicrobial resistance analysis revealed high levels of resistance to ampicillin (89.7%) and penicillin G (87.2%), with 71.8% of the isolates demonstrating multidrug resistance. Of the 16 S. aureus isolates analyzed using PCR, all were found to carry the nuc gene, with the mecA and blaZ genes detected in 50% of these isolates each. This study revealed the widespread distribution of S. aureus in milk and milk products in the Arsi highlands of Ethiopia. The isolates displayed high resistance to ampicillin and penicillin, with a concerning level of multidrug resistance. The detection of the mecA and blaZ genes in selected isolates is of particular concern, highlighting a potential public health hazard and posing a challenge to effective antimicrobial treatment. These findings highlight the urgent need to enhance hygiene standards in milk and milk product handling and promote the rational use of antimicrobial drugs. Provision of adequate training for all individuals involved in the dairy sector can help minimize contamination. These measures are crucial in addressing the threats posed by S. aureus, including methicillin-resistant strains, and ensuring the safety of milk and its products for consumers.

Antimicrobial Resistance in Gonorrhea.

Antimicrobial resistance is a global public health emergency. The World Health Organization recently highlighted the growing number of new sexually transmitted infections such as gonorrhea, syphilis, and Chlamydia, which are resistant to common antibiotics. The phenomenon is also on the rise due to increasing intercontinental travel. Emerging antibiotic-resistant strains of gonorrhea are particularly associated with international spread from Southeast Asian travelers. Infection with Neisseria gonorrhoeae can cause a wide spectrum of associated diseases such as dermatitis, arthritis and septic arthritis, and pelvic inflammatory disease, and can even lead to serious health consequences for the individual. Natural infection confers no immunity, and vaccination is not available currently, although in several countries, it has been reported that the antimeningococcal vaccine may protect against gonorrhea. Implementing all necessary preventive measures is crucial, as well as appropriate and timely diagnostic methods and effective antimicrobial therapeutic treatments in the correct modalities to avoid the increase of forms of gonorrhea that are resistant to common antibiotics and difficult to eradicate.

Wearable Light Sources for Antimicrobial Photodynamic Therapy

SignificanceOrganic light emitting diodes (OLEDs) are desirable light sources for ambulatory photodynamic therapy (PDT) due to their compact size, light weight, and the possibility to be fabricated on a flexible substrate. Herein, we demonstrate the effectiveness of using red OLEDs as light sources for killing Staphylococcus aureus. ApproachFirstly, large area flexible OLEDs were fabricated. Then the efficacy of OLEDs for killing bacteria was tested on 96-well plates using different concentrations of methylene blue as a photosensitizer. Samples were illuminated for 1, 3 and 6 hours at an irradiance of 6 mW/cm2. The growth of live bacteria was monitored using a microplate reader. ResultsOur results showed that OLED-PDT can kill more than 99% of bacteria which provides effective antimicrobial treatment. ConclusionsThis work shows the great potential of OLEDs as new wearable light sources for antimicrobial treatment of Staphylococcus aureus.

Mussel‐Inspired Recombinant Adhesive Protein‐Based Functionalization for Consistent and Effective Antimicrobial Treatment in Chronic Inflammatory Skin Diseases (Adv. Therap. 4/2024)

Mussel‐Inspired Recombinant Adhesive Protein‐Based Functionalization for Consistent and Effective Antimicrobial Treatment in Chronic Inflammatory Skin Diseases (Adv. Therap. 4/2024)

Tigecycline as Salvage Therapy in a Neonate with Multidrug-resistant Klebsiella pneumoniae Meningitis and Ventriculitis – Case Report and Literature Review

Multi drug resistant (MDR) infections especially in paediatric population, with already limited treatment options, often leave clinicians at loss for an effective antimicrobial treatment making us as helpless as in pre-antibiotic era. Tigecycline is an ‘immature’ antibiotic for children. According to FDA, tigecycline is only indicated in patients 18 years of age and older for the treatment of complicated MDR infection. According to the published literature, the youngest patient on whom Tigecycline treatment has been attempted was 73 day old baby born at 27 weeks gestation with a birth weight of 1028 grams having Acinetobacter baumanii ventriculitis . Here, we discuss use of Tigecycline in a neonate with MDR Klebsiella Pneumoniae meningitis and ventriculitis who presented to us on day 12 of life. Child was born preterm at 34 weeks and 3 days by Lower Segment Caesarean Section in view of foetal distress, maternal preeclampsia and gestational hypothyroidism in a private hospital. On 12thday of life the baby presented to our hospital after being referred with complaints of abnormal body movements, lethargy, difficulty in taking feeds and difficulty in breathing. The complaints had been documented to be present since birth but were increasing over time. Aerobic culture of CSF led to isolation of multi-drug resistant (MDR) Klebsiella pneumoniae resistant to most empirical antibiotics, with intermediate susceptibility to Amikacin susceptibility to Colistin and Tigecycline. We found our isolate produced both NDM and OXA-48 contributing to the increased virulence and resistance of the strain. Considering the paucity of knowledge of Tigecycline’s efficacy and safety in children less than 8 years, lack of FDA approval and the fact that CSF bioavailability is considered low, Tigecycline therapy was deferred and infant was continued on injection Meropenem and injection Amikacin. Condition of child did not improve and marginal weight gain was documented over next 10 days. CSF culture from repeat LP again grew Klebsiella pneumoniae with same susceptibility pattern. On day 23 due adverse affects, and injection Tigecycline was added. A total of 42 days of Meropenem and 21 days of Tigecycline were completed and child was discharged after 42 days of hospital stay. Child was gaining weight, taking feeds orally and no abnormal body movements were present. The child is being followed up for long term sequelae of HIE 2 and meningitis on OPD basis

Survival of Listeria Strains and Shelf Life Determination of Fresh Blueberries (Vaccinium corymbosum) Treated with Cold Atmospheric Plasma.

Fresh blueberries are delicate, hand-picked, packaged, and refrigerated fruits vulnerable to spoilage and contamination. Cold atmospheric plasma (CAP) is a promising antimicrobial technology; therefore, this study evaluated the CAP treatment effect on acid-tolerant Listeria innocua and Listeria monocytogenes and evaluated changes in the quality of the treated fruit. Samples were spot-inoculated with pH 5.5 and 6.0 acid-adapted Listeria species. Samples were treated with gliding arc CAP for 15, 30, 45, and 60 s and evaluated after 0, 1, 4, 7, and 11 days of storage at 4 °C and 90% humidity for the following quality parameters: total aerobic counts, yeast and molds, texture, color, soluble solids, pH, and titratable acidity. CAP treatments of 30 s and over demonstrated significant reductions in pathogens under both the resistant strain and pH conditions. Sixty-second CAP achieved a 0.54 Log CFU g-1 reduction in L. monocytogenes (pH 5.5) and 0.28 Log CFU g-1 for L. monocytogenes (pH 6.0). Yeast and mold counts on day 0 showed statistically significant reductions after 30, 45, and 60 s CAP with an average 2.34 Log CFU g-1 reduction when compared to non-CAP treated samples. Quality parameters did not show major significant differences among CAP treatments during shelf life. CAP is an effective antimicrobial treatment that does not significantly affect fruit quality.

KPC-2 allelic variants in Klebsiella pneumoniae isolates resistant to ceftazidime-avibactam from Argentina: blaKPC-80, blaKPC-81, blaKPC-96 and blaKPC-97.

The emergence of ceftazidime-avibactam (CZA) resistance poses a significant threat to the efficacy of this life-saving therapy against carbapenem-resistant bacteria, particularly Klebsiella pneumoniae-producing KPC enzymes. This study investigates four clinical isolates exhibiting resistance to CZA, revealing novel allelic variants of the key resistance gene, blaKPC-2. The mutations identified in hotspots surrounding the active site of KPC, such as K269_D270insPNK, del_I173, Y241N and V277_I278insNSEAV, prove the adaptability of these pathogens. Intriguingly, low-level resistance to imipenem and disruptions in porin genes were observed, emphasizing the complexity of the resistance mechanisms. Interestingly, three of four isolates belonged to clonal complex 11. This research not only sheds light on the clinical significance of CZA resistance but also shows the urgency for comprehensive surveillance and molecular studies to inform effective antimicrobial treatment strategies in the face of evolving bacterial resistance.