New antibiotics for Gram-negative pneumonia

Rapid antibiotic biosensors based on multiple molecular recognition elements

The extensive use of antibiotics poses significant public health concerns, including the increase in drug-resistant bacteria and environmental pollution, underscoring the urgent need for rapid, sensitive, and specific antibiotic detection methods. Most current reviews on antibiotic detection primarily focus on categorizing antibiotics based on their types or the classification of sensors used, such as electrochemical, optical, or colorimetric sensors. In contrast, this review proposes a novel and systematic theoretical framework for the detection of antibiotics using sensors using seven popular molecular recognition elements-antibodies, aptamers, microorganisms, cells, peptides, molecularly imprinted polymers (MIPs), metal-organic frameworks (MOFs) and direct recognition modalities and briefly discusses the mechanism of molecular recognition elements and antibiotic recognition. Additionally, it explores biosensors developed using these elements, offering a detailed analysis of their strengths and limitations in terms of sensitivity, specificity, and practicality. The review concludes by addressing current challenges and future directions, providing a comprehensive perspective essential for enhancing food safety and protecting public health.

Synthetic approaches and therapeutic applications of FDA-approved antibacterial agents: A comprehensive review from 2003 to 2023

The increasing threat of antibiotic resistance has necessitated the development of new antibacterial agents. 33 novel antibacterial agents have been approved by the U.S. Food and Drug Administration (FDA) within the two-decade timeframe from 2003 to 2023. These novel antibacterial agents included new chemical classes, such as lipopeptides, 18-membered macrolides, diaromatic quinolones, and nitroimidazoles, as well as modified existing classes, such as quinolones, tetracyclines, β-lactams, macrolides, oxazolidinones, and aminoglycosides. Nonetheless, during these twenty years, approval for new antibiotics was notably absent in 6 different years, and the total number of antibiotics approved was considerably less than that of other drug classes, including anticancer drugs. In this review, we provide an extensive analysis of the synthetic approaches and therapeutic applications of these approved antibacterial agents. We believe that this review will help further research on potential antibacterial agents for clinical use and development of next generation of antibacterial agents.

Antimicrobial Resistance in ESKAPE Pathogens: A Retrospective Epidemiological Study at the University Hospital of Palermo, Italy

BACKGROUND

Antimicrobial resistance (AMR) is an escalating global health threat, projected to cause over 40 million deaths by 2050. ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are major contributors to nosocomial infections and AMR. We evaluated the epidemiology and AMR prevalence of ESKAPE pathogens at the University Hospital in Palermo between January 2018 and July 2023, analyzing factors associated with mortality in patients with positive blood cultures.

METHODS

Microbiological data from all specimen types were collected using the Business Intelligence system Biwer, excluding duplicates. We assessed the prevalence and trends of ESKAPE isolates and AMR over time. Clinical data from hospital discharge forms were used to evaluate factors associated with mortality in patients with ESKAPE-positive blood cultures. Differences in AMR prevalence between blood and non-blood isolates were examined.

RESULTS

A total of 11,607 specimens from 4916 patients were analyzed. Most patients were admitted to Internal Medicine (19.4%), the ICU (13.2%), and General Surgery (9.9%). Additionally, 21.5% of the specimens were collected from ICU-admitted patients. Blood cultures accounted for 14.3% of the specimens, urine for 25.3%, respiratory secretions for 22.1%, and skin and mucosal swabs for 20.9%. The prevalence of all isolates increased progressively, peaking in 2021. The vancomycin-resistant E. faecium prevalence was 19.4%, with a significant upward trend, while oxacillin-resistant S. aureus prevalence was 35.0%, showing a significant decline. A. baumannii exhibited high resistance to all antibiotics tested except for colistin and cefiderocol. Carbapenemase resistance was 55.0% in K. pneumoniae, 20.4% in P. aeruginosa, and 4.6% in Enterobacter spp. P. aeruginosa showed a significant decrease in meropenem resistance. K. pneumoniae and A. baumannii bloodstream infections were linked to higher mortality risk.

Acinetobacter baumannii Complex Infections: New Treatment Options in the Antibiotic Pipeline

Acinetobacter baumannii complex (ABC) can result in a panoply of severe syndromes, including pneumonia and septic shock. Options available for treating infections caused by ABC and, more importantly, by carbapenem-resistant ABC (CRAB) are limited because of the increasing prevalence of antimicrobial resistance. Furthermore, many older agents, such as polymyxin and colistin, have limited lung penetration and are associated with significant toxicities. These factors underscore the urgent need for new paradigms to address ABC and CRAB. Two agents, cefiderocol and sulbactam-durlobactam, are now available to treat CRAB infections. In addition, several anti-infectives that target CRAB are in later-stage clinical trials. In order to place these newer molecules in context and to help clinicians appreciate the emerging potential drug development pipeline, we describe the in vitro activity, mechanisms of action, and clinical trial data not only for the commercially now available alternatives, such as cefiderocol and sulbactam-durlobactam, but also review these topics for molecules undergoing phase II and III clinical trials. Specifically, we discuss and analyze data related to four novel drugs from ABC: BV-100, cefepime-zidebactam, zosurabalpin, and OMN6.

Azithromycin inhibits the intracellular persistence of Acinetobacter baumannii by inducing host cell autophagy in human bronchial epithelial cells

The invasion of host cells by bacteria, leading to intracellular infections, is a major cause of infection recurrence. Drug-resistant Acinetobacter baumannii (A. baumannii) is one of the most challenging public health issues worldwide, with very limited clinical treatment options available. A. baumannii has been found to be able to invade host cells and proliferate within them in recent studies. In addition to the direct antimicrobial effect of antibiotics, the activation of host autophagic flux also plays an important role in eliminating intracellular pathogens. Herein, this study aimes to evaluate the clearance effect of antibiotics on intracellular A. baumannii both in vivo and in vitro, and explore the relationship between this effect and autophagy. The results showed that intracellular pathogens resulted in a significant increase in the minimum bactericidal concentration, while azithromycin can significantly eliminate intracellular A. baumannii in vitro and in vivo. Notably, 60 μg/mL azithromycin demonstrated intracellular clearance against multidrug-resistant A. baumannii and markedly induced autophagosomes in BEAS-2B cells with a mild stimulation of autophagosomes degradation. These findings indicated that azithromycin can significantly clear intracellular A. baumannii and its ability to clear intracellular A. baumannii may be related to the stimulation of autophagosome formation and the induction of host autophagy, which has important implications for the clinical treatment of A. baumannii infections, especially when intracellular infections are present.

Blue light-activated 5,10,15,20-tetrakis(4-bromophenyl)porphyrin for photodynamic eradication of drug-resistant Staphylococcus aureus

Photodynamic therapy (PDT) has emerged as an effective way to deal with drug-resistant bacterial infections. Especially, blue light (BL) mediated PDT (BL-PDT) presents unique advantages in the treatments of skin infection due to the strong light absorption of superficial skin, weak penetration of BL and little damage to deep tissues. However, the photosensitizers used for BL-PDT are very limited, and the ongoing development of novel BL photosensitizers is indispensable. Porphyrins are good sources for developing efficient photosensitizers. Herein, for developing more effective BL photosensitizers, five porphyrin derivatives that can be excited by BL [5,10,15,20-tetraphenylporphyrin (TPP), 5,10,15,20-tetrakis(4-bromophenyl)porphyrin (TBPP), 5,10,15,20-tetrakis(4-chlorophenyl)porphyrin (TCPP), 5,10,15,20-tetrakis(4-fluorophenyl)porphyrin (TFPP), 5,10,15,20-tetrakis(4-iodophenyl)porphyrin (TIPP)] are subjected to the investigation of PDT against MRSA (methicillin resistant Staphylococcus aureus). The results reveal that TBPP-mediated BL-PDT shows outstanding bactericidal effects. Mechanism studies show that TBPP + BL can induce reactive oxygen species (ROS) up-regulated in MRSA, rupture cell membrane, inhibit ATP (adenosine triphosphate) production and virulence factor expression. Furthermore, TBPP + BL effectively eliminates MRSA form biofilms, inhibits biofilm formation and disintegrates mature biofilms. More importantly, TBPP-PDT significantly accelerate mouse skin wound healing in a biofilm infection model. Our work offers new insights into the development of novel BL photosensitizers.

Ceftolozane/Tazobactam treatment for patients with hospital-acquired and ventilatory-associated bacterial pneumonia in Canada in 2022-2024: results from the CLEAR registry

BACKGROUND

We report results from the national CLEAR (Canadian Leadership on Antimicrobial Real-Life Usage) registry on the usage of ceftolozane/tazobactam in Canada from 2022 to 2024.

RESEARCH DESIGN AND METHODS

The authors reviewed the final data using the national ethics approved CLEAR study. Thereafter, the literature is surveyed regarding the usage of ceftolozane/tazobactam to treat patients with HABP and VABP via PubMed (up to May 2024).

RESULTS

Ceftolozane/tazobactam was primarily used as directed therapy to treat HABP and VABP caused by Pseudomonas aeruginosa. It was primarily used alone, or in combination with another agent, to treat resistant and multidrug-resistant (MDR) P. aeruginosa infections. Despite primarily being used to treat severely ill patients in intensive care units, its use was associated with relatively high microbiological/clinical cure rates, along with an excellent safety profile. Several reports attest to the microbiological/clinical efficacy and safety of using ceftolozane/tazobactam to treat HABP and VABP.

CONCLUSIONS

In Canada, ceftolozane/tazobactam is primarily used as directed therapy alone, or in combination, to treat MDR P. aeruginosa infections. Though mostly used to treat severely ill patients in the ICU, ceftolozane/tazobactam use in HABP and VABP is associated with relatively high microbiological/clinical cure rates and an excellent safety profile.

Efficacy of Ambroxol Combined with Loquat Syrup on Bacterial Pneumonia in Mice

Purpose

Bacterial pneumonia is a prevalent respiratory disease and a primary cause of death among hospitalized patients. Ambroxol and loquat syrup are widely utilized pharmaceuticals for managing respiratory infections in China. This study investigates the potential application and efficacy of combining ambroxol with loquat syrup for treating bacterial pneumonia.

Methods

In this study, mice with P. aeruginosa-induced bacterial pneumonia were used to evaluate the therapeutic effects of ambroxol, loquat syrup, and their combination. A bacterial plate coating assay was performed to measure the P. aeruginosa content in saliva, lung tissue, and bronchoalveolar lavage fluid (BALF). A plate colony counting assay was conducted to assess the antibacterial activity of ambroxol and loquat syrup. Serum, BALF, and lung tissues were analyzed using qPCR, ELISA, immunohistochemistry, and hematoxylin-eosin staining to evaluate disease severity.

Results

In this study, the experimental results demonstrate that, compared to treatment with ambroxol and/or loquat syrup alone, the combined administration of ambroxol and loquat syrup significantly increases the volume of saliva expectorated by mice infected with bacteria, concurrently augmenting bacterial presence in saliva while diminishing bacterial burden in the lungs, with significant differences observed (p<0.05). Furthermore, the combined therapy of ambroxol and loquat syrup achieved better therapeutic effects on P. aeruginosa pneumonia compared to ambroxol and/or loquat syrup alone (p<0.05), as evidenced by significantly reduced P. aeruginosa-induced lung injury, improved lung permeability, decreased inflammatory cell infiltration, and lower expression of inflammatory cytokines.

Conclusion

These findings suggest that the combination therapy of ambroxol and loquat syrup presents a safe and feasible new treatment strategy for bacterial pneumonia, offering promising benefits for ameliorating lung tissue damage and inflammation.

Impact of adequate empirical combination therapy on mortality in septic shock due to Pseudomonas aeruginosa bloodstream infections: a multicentre retrospective cohort study

OBJECTIVES

To determine the association of adequate empirical combination therapy (AECT) with 30-day all-cause mortality in patients with septic shock due to Pseudomonas aeruginosa bloodstream infections (BSI).

METHODS

This multicentre, retrospective cohort study analysed data from 14 public hospitals in Italy, including all consecutive adult patients admitted during 2021-2022 with septic shock due to P. aeruginosa BSI. We compared the outcomes of patients receiving AECT to those on adequate empirical monotherapy (AEMT) using Cox regression analyses.

RESULTS

Of the 98 patients who received adequate empirical antibiotic treatment for septic shock due to P. aeruginosa BSI, 24 underwent AECT and 74 were given AEMT. AECT was associated with a lower 30-day all-cause mortality (25%, six out of 24) compared to AEMT (56.8%, 42 out of 74; P = 0.007). Multivariate Cox regression analysis indicated AECT as the only factor significantly associated with improved survival (aHR 0.30; 95% CI 0.12-0.71; P = 0.006). By contrast, the use of monotherapy or combination therapy in the definitive regimen did not influence mortality (aHR 0.73; 95% CI 0.25-2.14; P = 0.568).

CONCLUSIONS

AECT may be associated with reduced mortality compared to monotherapy in septic shock patients due to P. aeruginosa BSI. However, the administration of definitive adequate monotherapy or combination therapy yields similar outcomes, suggesting that once susceptibility is documented, switching to a single active in vitro drug is safe and feasible. Further studies are recommended to validate these findings.

In-vitro activities of essential antimicrobial agents including aztreonam/avibactam, eravacycline, colistin and other comparators against carbapenem-resistant bacteria with different carbapenemase genes: A multi-centre study in China, 2021

OBJECTIVE

Carbapenem-resistant bacteria (CRB), including carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa (CRPA) and carbapenem-resistant Enterobacterales (CRE), pose a considerable threat to public health in China. Eravacycline, aztreonam/avibactam and colistin are important antimicrobial agents for the treatment of serious infections caused by CRB. This study aimed to evaluate the prevalence of CRB strains, and the susceptibility of commonly used clinical antimicrobial agents against strains with different carbapenemase genes.

METHODS

In total, 7194 gram-negative bacteria strains were collected from different regions of China, and 924 carbapenem-resistant strains were identified. All strains were from confirmed infections. Antimicrobial susceptibility testing, covering 21 antimicrobial agents including aztreonam/avibactam, eravacycline, colistin and other comparators, was performed using the broth microdilution method. Carbapenemase genes (blaKPC, blaNDM, blaOXA, blaIMP and blaVIM) were screened using polymerase chain reaction amplification and sequence analysis. All statistical analyses were performed using Statistical Package for the Social Sciences Version 23.0.

RESULTS

The isolation rates of CRE, CRAB and CRPA were 6.31% (332/5265), 62.95% (440/699) and 15.20% (152/1000), respectively. The predominant carbapenemase in carbapenem-resistant Escherichia coli (CRECO) was NDM, while in carbapenem-resistant Klebsiella pneumoniae (CRKP), it was KPC. All CRAB produced OXA-23, and 85.52% of CRPA did not produce any of the following carbapenemases: NDM, KPC, VIM, IMP and OXA. Aztreonam/avibactam, colistin and eravacycline exhibited high antimicrobial activity against different species producing various carbapenemases. Compared with ceftazidime/avibactam, aztreonam/avibactam demonstrated superior antimicrobial activity, particularly pronounced in CRECO and strains producing metallo-beta-lactamases. In comparisons between tigecycline and eravacycline, the latter maintained higher antimicrobial activity across different species. Antimicrobial agents exhibited varying levels of activity against strains with different resistance mechanisms.

CONCLUSIONS

Using aztreonam/avibactam, eravacycline and colistin to treat infections caused by CRB offers significant advantages. These findings will guide clinical practice and optimize antimicrobial administration.

Agents Targeting the Bacterial Cell Wall as Tools to Combat Gram-Positive Pathogens

The cell wall is an indispensable element of bacterial cells and a long-known target of many antibiotics. Penicillin, the first discovered beta-lactam antibiotic inhibiting the synthesis of cell walls, was successfully used to cure many bacterial infections. Unfortunately, pathogens eventually developed resistance to it. This started an arms race, and while novel beta-lactams, either natural or (semi)synthetic, were discovered, soon upon their application, bacteria were developing resistance. Currently, we are facing the threat of losing the race since more and more multidrug-resistant (MDR) pathogens are emerging. Therefore, there is an urgent need for developing novel approaches to combat MDR bacteria. The cell wall is a reasonable candidate for a target as it differentiates not only bacterial and human cells but also has a specific composition unique to various groups of bacteria. This ensures the safety and specificity of novel antibacterial agents that target this structure. Due to the shortage of low-molecular-weight candidates for novel antibiotics, attention was focused on peptides and proteins that possess antibacterial activity. Here, we describe proteinaceous agents of various origins that target bacterial cell wall, including bacteriocins and phage and bacterial lysins, as alternatives to classic antibiotic candidates for antimicrobial drugs. Moreover, advancements in protein chemistry and engineering currently allow for the production of stable, specific, and effective drugs. Finally, we introduce the concept of selective targeting of dangerous pathogens, exemplified by staphylococci, by agents specifically disrupting their cell walls.

Rapid Molecular Diagnostics of Pneumonia Caused by Gram-Negative Bacteria: A Clinician's Review

With approximately half a billion events per year, lower respiratory tract infections (LRTIs) represent a major challenge for the global public health. Among LRTI cases, those caused by Gram-negative bacteria (GNB) are associated with a poorer prognostic. Standard-of-care etiologic diagnostics is lengthy and difficult to establish, with more than half of cases remaining microbiologically undocumented. Recently, syndromic molecular diagnostic panels became available, enabling simultaneous detection of tens of pathogen-related and antimicrobial-resistance genetic markers within a few hours. In this narrative review, we summarize the available data on the performance of molecular diagnostics in GNB pneumonia, highlighting the main strengths and limitations of these assays, as well as the main factors influencing their clinical utility. We searched MEDLINE and Web of Science databases for relevant English-language articles. Molecular assays have higher analytical sensitivity than cultural methods, and show good agreement with standard-of-care diagnostics regarding detection of respiratory pathogens, including GNB, and identification of frequent patterns of resistance to antibiotics. Clinical trials reported encouraging results on the usefulness of molecular assays in antibiotic stewardship. By providing early information on the presence of pathogens and their probable resistance phenotypes, these assays assist in the choice of targeted therapy, in shortening the time from sample collection to appropriate antimicrobial treatment, and in reducing unnecessary antibiotic use.

Combinations of Antibiotics Effective against Extensively- and Pandrug-Resistant Acinetobacter baumannii Patient Isolates

Infections due to drug-resistant Acinetobacter baumannii strains are increasing and cause significant morbidity and mortality, especially in hospitalized and critically ill patients. A. baumannii rapidly develops resistance to numerous antibiotics, and antibiotics traditionally used against this deadly pathogen have been failing in recent years, highlighting the need to identify new treatment strategies. Treatment options that have shown promise include revisiting common antibiotics not typically used against A. baumannii, evaluating new antibiotics recently introduced to market, and identifying combinations of antibiotics that display synergistic interactions. In this study, we characterized the antibiotic susceptibility profiles of extensively (XDR) and pandrug-resistant (PDR) A. baumannii patient isolates. We examined the potency of 22 standard-of-care antibiotics and the newer antibiotics eravacycline, omadacycline, and plazomicin against these strains. Furthermore, we examined combinations of these antibiotics against our collection to identify synergistic effects. We found that this collection is highly resistant to most or all standard-of-care antibiotics, except for minocycline and rifampin. We show that eravacycline and omadacycline are effective against these strains based on minimum inhibitory concentrations. We also identified two highly effective combinations, cefepime and amikacin and cefepime and ampicillin-sulbactam, which exhibited high rates of synergy against this collection. This information is valuable in our battle against highly drug resistant and virtually untreatable A. baumannii infections.

Hospital-acquired bacterial pneumonia in critically ill patients: from research to clinical practice

INTRODUCTION

Hospital-acquired pneumonia (HAP) represents a significant cause of mortality among critically ill patients admitted to Intensive Care Units (ICUs). Timely and precise diagnosis is imperative to enhance therapeutic efficacy and patient outcomes. However, the diagnostic process is challenged by test limitations and a wide-ranging list of differential diagnoses, particularly in patients exhibiting escalating oxygen requirements, leukocytosis, and increased secretions.

AREAS COVERED

This narrative review aims to update diagnostic modalities, facilitating the prompt identification of nosocomial pneumonia while guiding, developing, and assessing therapeutic interventions. A comprehensive literature review was conducted utilizing the MEDLINE/PubMed database from 2013 to April 2024.

EXPERT OPINION

An integrated approach that integrates clinical, microbiological, and imaging tools is paramount. Progress in diagnostic techniques, including novel molecular methods, the expanding utilization and accuracy of bedside ultrasound, and the emergence of Artificial Intelligence, coupled with an improved comprehension of lung microbiota and host-pathogen interactions, continues to enhance our capability to accurately and swiftly identify HAP and its causative agents. This advancement enables the refinement of treatment strategies and facilitates the implementation of precision medicine approaches.

Reduce susceptibility to cefiderocol in gram negative bacteria in children: Is hope already lost before it's even arrived?

BACKGROUND

In last years the diffusion of carbapenem resistance in Gram-negative bacteria (CR-GNB) is increasing worldwide, mainly due to the expression of carbapenemases. Cefiderocol has molecular characteristics that ideally confers activity against all CR-GNB, but resistant strains have already been identified. We describe cefiderocol susceptibility profile among multi-drug resistant Gram-negative isolated from pediatric patients.

METHODS

Prospective, single pediatric center study, 1st January 2020-15th June 2023. All GNB carbapenemases producers or phenotypically carbapenem-resistant isolated in the study period were tested for cefiderocol susceptibility. Clinical and microbiological data were collected. A descriptive analysis was performed, comparing the groups of cefiderocol-resistant vs. cefiderocol-susceptible Enterobacterales and non-fermenting Gram-negative bacteria (NF-GNB).

RESULTS

Forty-seven GNB were tested for cefiderocol susceptibility; 38% were cefiderocol-resistant: 16/30 (52%) among Enterobacterales and 2/17 (12%) among NF-GNB. None of the patients were previously exposed to cefiderocol. Looking at Enterobacterales, resistance to ceftazidime/avibactam was higher among cefiderocol-resistant vs. cefiderocol-susceptible strains (62% vs 36%, respectively), as MBL expression (67% vs. 36%, respectively). Too few NF-GNB were cefiderocol-resistance to draw any conclusion. No difference in ICU admission and mortality was identified comparing cefiderocol-resistant vs. susceptible strains. Patients colonized/infected by cefiderocol-resistant strains had been previously hospitalized more frequently.

CONCLUSION

In our cohort cefiderocol resistance was mostly registered among Enterobacterales, and especially among MBL producers' strains (that were alongside resistant to ceftazidime/avibactam). This could be explained by the known possible cross resistance mechanism among ceftazidime/avibactam and cefiderocol. Also, correlation of cefiderocol-resistance with previous hospitalization could be associated with horizontal resistance transmission. Looking at our data, we believe that cefiderocol should be use cautiously, especially empirically and in monotherapy, due to the high resistance rate.

Synergistic Antibacterial Activity of Gallic Acid Based Chalcone Indl 2 by Inhibiting Efflux Pump Transporters

As a part of novel discovery of drugs from natural resources, present study was undertaken to explore the antibacterial potential of chalcone Indl-2 in combination with different group of antibiotics. MIC of antibiotics was reduced up to eight folds against the different cultures of E. coli by both chalcones. Among the two compounds, the i. e. 1-(3', 4,'5'-trimethoxyphenyl)-3-(3-Indyl)-prop-2-enone (6, Indl-2), a chalcone derivative of gallic acid (Indl-2) was better along with tetracycline (TET) worked synergistically and was found to inhibit efflux transporters as obvious by ethidium bromide efflux confirmed by ATPase assays and docking studies. In combination, Indl-2 kills the MDREC-KG4 cells, post-antibiotic effect (PAE) of TET was prolonged and mutant prevention concentration (MPC) of TET was also decreased. In-vivo studies revealed that Indl-2 reduces the concentration of TNF-α. In acute oral toxicity study, Indl-2 was non-toxic and well tolerated up-to dose of 2000 mg/kg. Perhaps, the study is going to report gallic acid derived chalcone as synergistic agent acting via inhibiting the primary efflux pumps.

Treatment Failure and Clinical Stability in Severe Community-Acquired Pneumonia

Treatment failure and clinical stability are important outcomes in community-acquired pneumonia (CAP). It is essential to know the causes and risk factors for treatment failure and delay in reaching clinical stability in CAP. The study of both as well as the associated underlying mechanisms and host response are key to improving outcomes in pneumonia.

Insights into the eradication of drug resistant Staphylococcus aureus via compound 6-nitrobenzo[cd]indole-2(1H)-ketone

6-Nitrobenzo[cd]indole-2(1H)-ketone (compound C2) exhibits an excellent germicidal effect against methicillin-resistant Staphylococcus aureus (MRSA). Mechanism studies show that C2 induces ROS over-production, cell membrane damage, and ATP and virulence factor down-regulation in bacteria. More importantly, C2 can inhibit biofilm formation and accelerate wound healing in a mouse infection model induced by MRSA.

Trends and patterns of antibiotics use in Serbia from 2006 to 2021: Pre-COVID-19 period versus COVID-19 pandemic

BACKGROUND

Global rise in antibiotic utilization has been strongly associated with the resistance of bacteria to antibiotics. The COVID-19 saw an increase in the use of antibiotics in some countries. The aim of this study was to evaluate antibiotic utilization from 2006 to 2021 in the Republic of Serbia.

METHODS

Data on antibiotic use were retrieved from the national annual reports on the official website of the Medicines and Medical Devices Agency of Serbia during the period 2006 to 2021. To evaluate trends in the use of antibiotics in Serbia, linear, and joint regression analyses were performed.

RESULTS

The analysis of the antibiotics use over a sixteen-year period included a total of 50 antibiotics. A significant increase during the COVID-19 pandemic was observed for glycylcyclines that is, new-generation tetracyclines (tigecycline), third-generation cephalosporins (ceftazidime, ceftriaxone, and cefixime), respiratory fluoroquinolones (levofloxacin and moxifloxacin), carbapenems (ertapenem), and oxazolidinones (linezolid) utilization. Moreover, an almost negligible use of new β-lactam/β-lactamase inhibitors during the prepandemic period increased significantly during the COVID-19 pandemic period.

CONCLUSIONS

A significant increasing trend in the use of specific antibiotics classified as the "Watch" and "Reserve" antibiotics during the pandemic period was observed.

Risk Factors for 30-Day Mortality in Patients with Bacteremic Pneumonia Caused by Escherichia coli and Klebsiella pneumoniae: A Retrospective Study

Objective

Escherichia coli and Klebsiella pneumoniae are prevalent Gram-negative microorganisms responsible for pneumonia, as well as the primary Enterobacteriaceae pathogens causing bacteremic pneumonia. The objective of this research is to analyze the risk factors associated with bacteremic pneumonia caused by these pathogens and develop a predictive model.

Patients and Methods

This retrospective investigation encompassed a cohort of 252 patients diagnosed with Escherichia coli or Klebsiella pneumoniae-induced bacteremic pneumonia between 2018 and 2022. The primary endpoint was 30-day mortality, which was analyzed using multifactorial logistic regression, nomogram construction, and Bootstrap validation.

Results

Among the 252 patients diagnosed with Escherichia coli and Klebsiella pneumoniae, 65 succumbed to the disease while 187 survived. The overall 30-day mortality was found to be 25.8%. A multifactorial logistic regression analysis revealed that diastolic blood pressure, cerebrovascular diseases/transient ischemic attacks (TIA), immunosuppression, blood urea nitrogen, Pitt score, and CURB-65 score were statistically significant factors. The Nomogram model demonstrated an AUC of 0.954, which closely aligns with the Bootstrap-derived mean AUC of 0.953 (95% CI: 0.952-0.954).

Conclusion

In patients with bacteremic pneumonia caused by Escherichia coli and Klebsiella pneumoniae, Low diastolic blood pressure (≤61 mmHg), pre-existing cerebrovascular disease/ transient ischemic attacks (TIA), immunosuppression status, elevated blood urea nitrogen levels (≥8.39 mmol/L), high Pitt score (≥3), and a high CURB-65 score (≥2) are all independent risk factors for Escherichia coli and Klebsiella pneumoniae bacteremic pneumonia, among which the first three warrant particular attention.

Harvesting phosphorus-containing moieties for their antibacterial effects

Clinically manifested resistance of bacteria to antibiotics has emerged as a global threat to society and there is an urgent need for the development of novel classes of antibacterial agents. Recently, the use of phosphorus in antibacterial agents has been explored in quite an unprecedent manner. In this comprehensive review, we summarize the use of phosphorus-containing moieties (phosphonates, phosphonamidates, phosphonopeptides, phosphates, phosphoramidates, phosphinates, phosphine oxides, and phosphoniums) in compounds with antibacterial effect, including their use as β-lactamase inhibitors and antibacterial disinfectants. We show that phosphorus-containing moieties can serve as novel pharmacophores, bioisosteres, and prodrugs to modify pharmacodynamic and pharmacokinetic properties. We further discuss the mechanisms of action, biological activities, clinical use and highlight possible future prospects.

Real-world in vitro activity of newer antibiotics against Enterobacterales and Pseudomonas aeruginosa, including carbapenem-non-susceptible and multidrug-resistant isolates: a multicenter analysis

IMPORTANCE

Newer antibiotics against Gram-negative pathogens provide important treatment options, especially for antibiotic-resistant bacteria, but little is known about their use during routine clinical care. To use these agents appropriately, clinicians need to have access to timely susceptibility data. We evaluated 27,531 facility-reported susceptibility results from the BD Insights Research Database to gain a better understanding of real-world testing practices and susceptibility rates for six newer antibiotics. Escherichia coli was the most frequently tested potential pathogen, and ceftazidime-avibactam and ceftolozane-tazobactam had the greatest numbers of susceptibility results. For cefiderocol, eravacycline, imipenem-relabactam, and meropenem-vaborbactam, susceptibility data were available for fewer than 2% of isolates. Susceptibility comparisons should be considered with caution. Ceftazidime-avibactam had the highest susceptibility rates for Enterobacterales while cefiderocol had the highest susceptibility rates for Pseudomonas aeruginosa. New antibiotics have the potential to improve the management of Gram-negative infections, but their use may be hampered by the absence of susceptibility data.

Antibiotic therapy for nonfermenting Gram-negative bacilli infections: future perspectives

PURPOSE OF REVIEW

Serious infections caused by nonfermenting Gram-negative bacteria (NF-GNB) pose a significant challenge for clinicians due to the limited treatment options available, which are frequently associated with issues of toxicity and unfavourable pharmacokinetic profiles. The aim of this review is to provide a brief overview of the existing data concerning the ongoing development of antiinfective agents targeting NF-GNB.

RECENT FINDINGS

Several agents exhibiting efficacy against NF-GNB are under clinical investigation. Durlobactam-sulbactam and cefepime-taniborbactam emerge as promising therapeutic avenues against carbapenem-resistant Acinetobacter baumanii . Cefepime-zidebactam may serve as a suitable treatment option for urinary tract infections caused by a wide range of NF-GNB. Cefepime-enmetazobactam demonstrates potent in vitro activity against various NF-GNB strains; however, its role as an anti- Pseudomonal agent is inadequately substantiated by available data. Xeruborbactam is a wide β-lactamase inhibitor that can be associated with a range of agents, enhancing in-vitro activity of these against many NF-GNB, including those resistant to newer, broader spectrum options. Lastly, murepavadin appears to be a potential pathogen-specific solution for severe Pseudomonas infections; however, additional investigation is necessary to establish the safety profile of this compound.

SUMMARY

Each of the novel molecules reviewed possesses an interesting range of in-vitro activity against NF-GNB. In addition, some of them have already been proved effective in vivo, underscoring their potential as future treatment options.