Gram-Negative Bacterial Infections - Science topic

Background Ceftazidime/avibactam, launched in the United Kingdom (UK) in March 2017, is an antibiotic against multidrug-resistant Gram-negative pathogens. It was selected for the government’s subscription model pilot, for incentivising new antibiotic development, which began in December 2020. Aim Ahead of the pilot, we assessed ceftazidime/avibact...

Introduction. Healthcare-associated infections (HAIs) are the leading cause of preventable death in neonatal intensive care units (NICUs), particularly among very low birth weight (VLBW) infants. Hypothesis/Gap Statement : VLBW neonates are at higher risk of HAIs, particularly those caused by Gram-negative bacteria (GNB) and fungi, which can negati...

Parachlamydia acanthamoebae is an obligate intracellular bacterium found in free-living Acanthamoeba amoebae. As with other Chlamydiales, P. acanthamoebae has a biphasic lifecycle with an infectious elementary body and a replicative reticulate body. Once inside a host, the elementary body differentiates to the reticulate body to undergo replication...

Background: The rise in multidrug-resistant (MDR) Gram-negative bacteria (GNB) poses a critical threat to global health, exacerbated by the increased use of antibiotics during the SARS-CoV-2 pandemic. Colistin, often considered a last-resort antibiotic, has seen heightened usage, raising concerns about resistance and clinical outcomes. This study i...

Cardiac implantable electronic device (CIED) infections caused by Gram-negative bacteria are uncommon but potentially life-threatening. This study examined patients with Gram-negative CIED infections, investigating the clinical characteristics of patients harboring multidrug-resistant (MDR), versus non-MDR, isolates. A retrospective observational a...

The Australian Group on Antimicrobial Resistance (AGAR) performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric gram-negative pathogens. From 1 January 2023 to 31 December 2023, a total of 57 hospitals across Australia participated in the Australian Gram-negative Surveillance Outcome Program (Gn...

This review provides an overview of recent research and advancements in infection prevention and the treatment of drug-resistant bacterial diseases. Cefiderocol, a novel siderophore cephalosporin, has demonstrated effectiveness against carbapenem-resistant bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii. Clinical trials, includi...

Urinary tract infections caused by Gram-negative bacteria (GNB) are among the most common infections and a significant cause of sepsis. The increasing prevalence of multidrug-resistant (MDR) bacteria poses challenges to empirical treatment. Colistin may be used a last-resort antibiotic for treating MDR infections, but this requires the rapid determ...

Introduction Multidrug resistant (MDR) Gram-negative bacterial infections are considered a major public health threat. The objectives of this study were to describe the epidemiology, potential contributing factors, and antimicrobial resistance patterns associated with infections caused by MDR Gram-negative bacteria (GNB) in non-immunocompromised ch...

Introduction Antimicrobial resistance is an important public health problem with a strong epidemiological, economic, and social impact. The objective of this analysis was to compare the cost effectiveness of imipenem-cilastatin-relebactam (IMI/CIL/REL) therapy with colistin-imipenem for the treatment of hospitalized patients with Gram-negative bact...

Achromobacter xylosoxidans is a rare opportunistic aerobe that has rarely been documented in the literature as a causative agent for osteomyelitis. It can present with antibiotic resistance, making treatment without operative management challenging. We present the case of a 51-year-old male with a past medical history of uncontrolled type 2 diabete...

Introduction: Carbapenems are last-resort antibiotics and are considered the drugs of choice for infections caused by multi-drug-resistant bacteria. During the last several years, there has been an alarming global increase in the detection and spread of Carbapenem-resistant organisms among gram-negative bacteria. Therefore, the main objective of th...

Background: The increased prevalence of antibiotic resistance among Gram-negative bacteria presents a severe public health challenge, leading to increased mortality rates, prolonged hospital stays, and higher medical costs. In Greece, the issue of multidrug-resistant Gram-negative bacteria is particularly alarming, exacerbated by overuse of antibio...

Background Shorter courses of antimicrobial therapy have been shown to be non-inferior to longer durations for the management of several infections. However, data on critically ill patients with severe infections by multidrug-resistant Gram-negative bacteria (MDR-GNB) are scarce. In the duratiOn of theraPy in severe infecTIons by MultIdrug-reSistan...

Background Pomegranate (Punica granatum), fruit rich in bioactive constituents, is used as a feed supplement against bacterial pathogens in aquaculture. Aim This study examined the effects of supplementing the diet of the common carp (Cyprino carpio) infected with Aeromonas veronii on growth and some hematological, biochemical, and immunological h...

Eikenella corrodens is a gram-negative, facultatively anaerobic bacterium typically found in the oropharynx and respiratory tract of humans. It is responsible for various infections, including head-and-neck infections, pericarditis, and abscesses of the deltoid, perirenal tissue, brain, and liver. Increasing antibiotic resistance requires urgent id...

Gram-negative bacteria in the nasopharynx can eventually invade bacteria-limited sites and cause serious illnesses such as meningitis, otitis media, and pneumonia. However, data related to the carriage of these bacteria in children attending outpatient departments in the study area are limited. To assess nasopharyngeal carriage, antibiotic suscepti...

Purpose Compared to conventional photodynamic therapy (PDT), oxygen-affording PDT represents a promising strategy for treating multidrug-resistant (MDR) gram-negative bacterial infections due to its enhanced sensitization ability towards bacteria and amplified therapeutic efficacy. Over the last decade, various nanoplatforms for the co-delivery of...

The common carp (Cyprinus carpio), a major economic freshwater fish, is suffering from a variety of bacterial infectious diseases because of its high-density, factory and intensive farming patterns. Aeromonas veronii is the causative agent of high mortality in common carp, causing severe economic losses in aquaculture. However, the regulatory mecha...

This study aims to determine the characteristics and distribution of pathogenic bacteria in bloodstream infections (BSIs) by gram-negative bacteria in adults. One hundred seventy-one adult patients with BSIs who were treated at the Affiliated Hospital of Chengde Medical College between January 2018 and January 2020 were included in this study. The...

Background/Objectives: The necessity for ground-breaking treatments for Gram-negative infections is evident. The World Health Organization, the Infectious Diseases Society of America, and the European Commission have highlighted the critical insufficiency of efficient antibiotics, urging pharmaceutical businesses to manufacture new antibiotics. The...

Purpose The international PROVE retrospective chart-review study aims to assess the real-world effectiveness and safety of cefiderocol for treatment of patients with carbapenem-resistant Gram-negative infections. Patients and Methods US centers selected hospitalized patients receiving their first cefiderocol treatment for ≥72 hours for a Gram-nega...

Introduction. Sepsis rates are increasing, with Gram-negative organisms representing a large proportion of bloodstream infections. Rapid antibiotic administration, alongside diagnostic investigations, is required for the effective management of these patients. Gap statement. Current diagnostics take ~48 h for a final report; therefore, rapid diagno...

Objective This study investigated the cytotoxic effects of Stenotrophomonas maltophilia on normal human cells. Methods Seven isolates of S. maltophilia were obtained from 120 urine samples collected from prostate and bladder cancer patients, with diagnoses confirmed via Vitek. The cytotoxicity of these bacterial isolates was assessed on normal hum...

Bloodstream infection is one of the most important and increasing complications in patients with severe burns. Most of the species affecting this population are Gram-negative bacilli that exhibit antimicrobial resistance. We conducted this study to determine the antimicrobial susceptibility profile and resistance mechanisms of these bacterial infec...

Purpose The diagnosis of liver abscess (LA) caused by Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB) depends on ultrasonography, but it is difficult to distinguish the overlapping features. Valuable ultrasonic (US) features were extracted to distinguish GPB-LA and GNB-LA and establish the relevant prediction model. Materials and Met...

Colistin is one of the last-resort antibiotics in treating infections caused by multidrug-resistant (MDR) pathogens. Unfortunately, the emergence of colistin-resistant gram-negative strains limit its clinical application. Here, we identify an FDA-approved drug, valnemulin (Val), exhibit a synergistic effect with colistin in eradicating both colisti...

Background Swine dysentery, caused by Brachyspira hyodysenteriae , is a severe pig disease. Resistance to tylosins is common and resistance to tiamulin has been reported since the 1990s. Still, dysentery is not notifiable to authorities. The disease therefore escapes control from an overall population perspective. In Sweden, a program that aimed to...

Background Multidrug-resistant Gram-negative bacterial infections are increasing globally in neonates, infants and children; antibiotic options are limited. Methods This international, multicenter, open-label phase 2 study, investigated the pharmacokinetics, safety and tolerability of single-dose and multiple-dose cefiderocol [as a 3-hour infusion...

Shewanella is an emerging human pathogen. It mostly causes skin and soft tissue infections. Osteosynthesis-associated infection involving Shewanella are rare and in most cases are secondary to direct contamination following open fractures in aquatic environments. Here, we present a rare case of hematogenous osteosynthesis-associated infection invol...

Background Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is a rapidly expanding life-support technique worldwide. The most common indications are severe hypoxemia and/or hypercapnia, unresponsive to conventional treatments, primarily in cases of acute respiratory distress syndrome. Concerning potential contraindications, there is no me...

The Clinical and Laboratory Standards Institute has published epidemiological cut-off values for susceptibility data generated at 22°°C and read after 44-48 h for florfenicol, oxolinic acid and oxytetracycline against Aeromonas salmonicida. The cut-off values for the minimum inhibitory concentration (MIC) and disc diffusion were derived from data o...

This is the first case report of decubitus infection and bacteremia due to Veillonella parvula (V. parvula). A patient in his 70s with pre-existing diabetes mellitus was admitted with decubitus infection, and tazobactam/piperacillin treatment was initiated. Tazobactam/piperacillin-resistant V. parvula was detected in the blood and decubitus site cu...

Multidrug-resistant (MDR) Gram-negative bacterial infections have emerged as a major public health concern. The aim of the present study was to detect the rate of infections due to MDR Gram-negative bacteria (GNB) in a tertiary care hospital, the rate of Carbapenemases and AmpC-β-lactamases production and the Antimicrobial susceptibility test patte...

We present the case of a 71-year-old man who developed sepsis caused by Capnocytophaga canimorsus as a result of being bitten by his own dog. Positive blood cultures were obtained, but due to difficulties in determining the bacterial species, the patient was treated empirically with ceftriaxone and levofloxacin. After using the recommended empirica...

Stenotrophomonas maltophilia was considered to be a low-virulence organism. But it has emerged as a prominent opportunistic pathogen in patients with certain risk factors. This study aimed to describe an outbreak experienced in our hospital with all dynamics while evaluating previous S. maltophilia outbreak reports. S. maltophilia isolates were obt...

Background Among the non-traditional antibacterial agents in development, only a few targets critical Gram-negative bacteria such as carbapenem-resistant Pseudomonas aeruginosa, Acinetobacter baumannii or cephalosporin-resistant Enterobacteriaceae. Endolysins and their genetically modified versions meet the World Health Organization criteria for in...

Background Polymyxin B (PMB)-based combination therapies are used to treat severe carbapenem-resistant gram-negative bacterial (CR-GNB) infections. This observational study investigated the relationship between clinical factors, including PMB concentration, and clinical efficacy and safety. Patients and Methods Polymyxin B regimens were optimized...

Background The optimal administration of polymyxins for treating multidrug-resistant gram-negative bacterial (MDR-GNB) pneumonia remains unclear. This study aimed to systematically assess the efficacy and safety of three polymyxin-containing regimens by conducting a comprehensive network meta-analysis. Methods We comprehensively searched nine data...

A reliable and above all, rapid antimicrobial susceptibility test (AST) is required for the diganostics of blood stream infections (BSI). In this study, resistance testing using DxM MicroScan WalkAway (MicroScan) from a 4-h subculture is compared with the standard overnight culture (18–24 h). Randomly selected positive blood cultures (PBC, n = 102)...

Introduction Recent studies suggested the potential benefits of extended infusion times to optimize the treatment efficacy of ceftazidime/avibactam, which indicated that the current pharmacokinetic/pharmacodynamic (PK/PD) target may not be sufficient, especially for severe infections. The purpose of this study is to assess the adequacy of dosing st...

Objectives The risk factors and outcomes associated with persistent bacteraemia in Gram-negative bloodstream infection (GN-BSI) are not well described. We conducted a follow-on analysis of a retrospective population-wide cohort to characterize persistent bacteraemia in patients with GN-BSI. Methods We included all hospitalized patients >18 years o...

Capnocytophaga canimorsus and Capnocytophaga cynodegmi are commensal bacteria in the oral cavities of dogs. Both are zoonotic pathogens that could infect humans via dog bites. C. canimorsus may cause life-threatening infections in humans, whereas C. cynodegmi infections tend to be milder and more localized. Capsular serovars A–C of C. canimorsus se...

Spiroplasma, belonging to the class Mollicutes, is a small, helical, motile bacterium lacking a cell wall. Its host range includes insects, plants, and aquatic crustaceans. Recently, a few human cases of Spiroplasma infection have been reported. The diseases caused by Spiroplasma have brought about serious economic losses and hindered the healthy d...

We describe an outbreak of Ralstonia pickettii in the United Kingdom, with isolates genetically indistinguishable from a 2023 Australian outbreak linked to internationally distributed saline solutions. Confirmed cases (n = 3) had bacteraemia, clinically relevant infection, indwelling venous lines and frequent healthcare contact. Multi-stakeholder i...

Objective: Hospital-associated multidrug-resistant infections are currently on the rise. Widespread resistance to antibiotics and limited therapeutic options make it a challenge to eradicate these infections. Therefore, the use of different antibiotics was increased in pediatric intensive care (PICU). Fluoroquinolones belong to a class of broad-spe...

Stenotrophomonas maltophilia is a nonfermenting gram-negative bacterium associated with multiple nosocomial outbreaks. Antibiotic resistance increases healthcare costs, disease severity, and mortality. Multidrug-resistant infections (such as S. maltophilia infection) are difficult to treat with conventional antimicrobials. This study aimed to inves...

Zoliflodacin is a spiropyrimidinetrione antibiotic that acts by binding to the GyrB part of the DNA gyrase enzyme in bacteria. Its effectiveness for the treatment of Neisseria gonorrhoeae infections has been investigated extensively. Since antibiotic resistance has been reached an alarming rate worldwide, researches on new antimicrobials are consid...

Introduction. Critically ill COVID-19 patients hospitalized in intensive care units (ICU) are immunosuppressed due to SARSCoV-2-related immunological effects and are administered immunomodulatory drugs. This study aimed to determine whether these patients carry an increased risk of multi-drug resistant (MDR) and especially carbapenem-resistant Gram...

The emergence of antimicrobial resistance represents a serious threat to public health and for infections due to multidrug-resistant (MDR) microorganisms, representing one of the most important causes of death worldwide. The renewal of old antimicrobials, such as colistin, has been proposed as a valuable therapeutic alternative to the emergence of...

Cephalosporins are a class of β-lactam antimicrobials employed in treating a wide array of infections caused by both gram-positive and gram-negative bacteria. The five generations of cephalosporins demonstrate effectiveness in treating conditions such as skin and soft tissue infections, pneumonia, and meningitis. Cefiderocol, a recently approved si...

Solid organ transplant (SOT) recipients are particularly susceptible to infections caused by multidrug-resistant organisms (MDRO) and are often the first to be affected by an emerging resistant pathogen. Unfortunately, their prevalence and impact on morbidity and mortality according to the type of graft is not systematically reported from high-as w...

Background Achromobacter spp. are opportunistic pathogens, mostly infecting immunocompromised patients and patients with cystic fibrosis (CF) and considered as difficult-to-treat pathogens due to both intrinsic resistance and the possibility of acquired antimicrobial resistance. Species identification remains challenging leading to imprecise descri...

Grass Carp Reovirus (GCRV) and Aeromonas hydrophila (Ah) are the causative agents of haemorrhagic disease in grass carp. This study aimed to investigate the molecular mechanisms and immune responses at the miRNA, mRNA, and protein levels in grass carp kidney cells (CIK) infected by Grass Carp Reovirus (GCRV, NV) and Aeromonas hydrophilus (Bacteria,...

We present a case of bilateral endogenous endophthalmitis with an extremely rare etiology of Capnocytophaga canimorsus. A 42-year-old asplenic patient with bilateral deterioration of visual acuity presented to the Emergency Department. The sudden deterioration of visual acuity, which prompted the patient to visit the ophthalmologist, was the first...

Aeromonas spp. are commonly found in the aquatic environment and have been responsible for motile Aeromonas septicemia (MAS) in striped catfish, resulting in significant economic loss. These organisms also cause a range of opportunistic infections in humans with compromised immune systems. Here, we conducted a genomic investigation of 87 Aeromonas...

Gram-negative bacteria (GNB) are a major cause of neonatal sepsis in low- and middle-income countries (LMICs). Although the World Health Organization (WHO) reports that over 80% of these sepsis deaths could be prevented through improved treatment, the efficacy of the currently recommended first- and second-line treatment regimens for this condition...

Innate immune response is the first line of host defense against pathogenic microorganisms, and its excessive or insufficient activation is detrimental to the organism. Many individual microRNAs (miRNAs) have emerged as crucial post-transcriptional regulators of immune homeostasis in Drosophila melanogaster. However, the synergistical regulation of...

C-type lectins in organisms play an important role in the process of innate immunity. In this study, a C-type lectin belonging to the DC-SIGN class of Micropterus salmoides was identified. MsDC-SIGN is classified as a type II transmembrane protein. The extracellular segment of MsDC-SIGN possesses a coiled-coil region and a carbohydrate recognition...

We report a case of Sphingobium yanoikuyae bacteremia in an 89-year-old patient in Japan. No standard antimicrobial regimen has been established for S. yanoikuyae infections. However, ceftriaxone and ceftazidime treatments were effective in this case. Increased antimicrobial susceptibility data are needed to establish appropriate treatments for S....

Aeromonas caviae is an emerging human enteric pathogen. However, the genomic features and virulence genes of A. caviae strains from human gastroenteritis and other sources have not been fully elucidated. Here, we conducted a genomic analysis of 565 global A. caviae strains isolated from different sources, including 261 strains isolated from faecal...

BACKGROUND Peritoneal dialysis (PD) serves as a critical renal replacement therapy for individuals with end-stage renal disease (ESRD), leveraging the peritoneum for fluid and substance exchange. Despite its effectiveness, PD is marred by complications such as peritonitis, which significantly impacts patient outcomes. The novelty of our report lies...

Purpose Since the introduction of ceftazidime–avibactam (CZA) in the Chinese market, accumulating clinical evidence has substantiated its efficacy in the treatment of infections caused by carbapenem-resistant gram-negative bacteria (CR-GNB). Nevertheless, an ongoing debate persists concerning the choice between monotherapy and combination therapy w...

The growing increase in the fish farming sector has favored the establishment of bacterial outbreaks caused by Aeromonas hydrophila in several species. The hexane extract of Hesperozygis ringens (HEHR) (Lamiaceae) leaves increased the survival rate of silver catfish (Rhamdia quelen) experimentally infected by A. hydrophila. However, it is noteworth...

Few studies describe the frequency of antibiotic regimen modification behaviors in the acute care setting. We sought to ascertain patient and treatment characteristics, details of regimen modification, and clinical outcomes with antibiotic modifications. This retrospective study included patients admitted to Hoag Memorial Hospital from 1 January 20...

Compounds that potentiate the activity of clinically available antibiotics provide a complementary solution, except for developing novel antibiotics for the rapid emergence of multidrug-resistant Gram-negative bacteria (GNB). We sought to identify compounds potentiating polymyxin B (PMB), a traditional drug that has been revived as the last line fo...

Shorter courses of antimicrobials have been shown to be non-inferior to longer, “traditional” duration of therapies, including for some severe healthcare-associated infections, with a few exceptions. However, evidence is lacking regarding shorter regimes against severe infections by multidrug-resistant Gram-negative bacteria (MDR-GNB), which are of...

Interleukin-6 (IL-6), a pleiotropic cytokine, plays a crucial role in acute stress induced by bacterial infection and is strongly associated with reactive oxygen species (ROS) production. However, the role of IL-6 in the liver of fish after Aeromonas hydrophila infection remains unclear. Therefore, this study constructed a zebrafish (Danio rerio) i...

Background Intravenous (IV) fosfomycin is increasingly used globally for treatment of infections due to multidrug-resistant Gram-negative bacteria (GNB). This study aimed to determine the optimal dosage of IV fosfomycin for patients with varying degrees of kidney function. Methods Eligible patients were adults ≥ 18 years who were treated with IV f...

Background There are few studies describing the rationale or frequency of empiric or directed therapy treatment modification behaviors among patients with complicated Gram-negative bacterial infections (GNBI). We sought to characterize patient and treatment characteristics, details of regimen modification, and patient outcomes. Methods This retros...

Gram-negative bacterial infections pose a significant challenge due to two major resistance elements, including the impermeability of outer membrane and the overexpression of efflux pumps, which contribute to antibiotic resistance....

Sepsis is a life-threatening complication of an infectious process that results from the excessive and uncontrolled activation of the host's pro-inflammatory immune response to a pathogen. Lipopolysaccharide (LPS), also known as endotoxin, which is a major component of Gram-negative bacteria's outer membrane, plays a key role in the development of...

Surveillance of antimicrobial resistance among gram-negative bacteria (GNB) is of critical importance, but data for Peru are not available. To fill this gap, a non-interventional hospital-based surveillance study was conducted in 15 hospitals across Peru from July 2017 to October 2019. Consecutive unique blood culture isolates of key GNB ( Escheric...

Extensive drug resistance to bacterial infections in hospitalised patients is accompanied by high morbidity and mortality rates due to limited treatment options. This study investigated the clinical outcomes of single and combined antibiotic therapies in extensive (XDR), multidrug-resistant (MDR) and susceptible strains (SS) of hospital-acquired in...

Clinical outcome of Gram negative bacterial infections in patients with HAIs exhibiting XDR, MDR and CRE.

Introduction: Antimicrobial resistance remains a serious and growing threat to public health, both globally and in the UK, leading to diminishing effectiveness of antimicrobials. Despite a clear need for new antimicrobials, the clinical pipeline is insufficient, driven by high research and development costs and limited expected returns on investme...

Introduction Multidrug-resistant bacterial infections limit available therapeutic options. Doxycycline is an old antibiotic from the tetracycline class that exhibits a wide antibacterial action, including Gram-negative bacteria (GNB), and could be an alternative for the treatment of multidrug-resistant (MDR) Enterobacteriaceae . The study aimed to...