Colistin and S. Maltophilia

WCK 5222 (cefepime-zidebactam, 2 g + 1g, every 8 h [q8h]) is in clinical development for the treatment of infections caused by carbapenem-resistant and multidrug-resistant (MDR) Gram-negative bacilli. We determined the in vitro susceptibility of 1,385 clinical isolates of non-carbapenem-susceptible Enterobacterales , MDR Pseudomonas aeruginosa (also non-carbapenem susceptible), Stenotrophomonas maltophilia , and Burkholderia spp. collected worldwide (49 countries) from 2014 to 2016 to cefepime-zidebactam (1:1 ratio), ceftazidime-avibactam, imipenem-relebactam, ceftolozane-tazobactam, and colistin using the CLSI broth microdilution method...

Due to the rapid increase of antimicrobial resistance with ensuring therapeutic failures, the purpose of this study was to identify novel synthetic molecules as alternatives to conventional available, but presently ineffective antibiotics. Variously structured cationic dendrimers previously reported have provided promising outcomes. However, the problem of their cytotoxicity towards eukaryotic cells has not been completely overcome. We have now investigated the antibacterial activities of three not cytotoxic cationic dendrimers (G5Ds: G5H, G5K, and G5HK) against several multidrug-resistant (MDR) clinical strains...

Stenotrophomonas maltophilia is an aerobic, oxidase-negative and catalase-positive bacillus. S. maltophilia is a recognized opportunistic pathogen. Due to the advancements in invasive medical procedures, organ transplantation and chemotherapy of malignant illnesses, the relevance of this pathogen increased significantly. The therapy of S. maltophilia infections is challenging, as these bacteria show intrinsic resistance to multiple classes of antibiotics, the first-choice drug is sulfamethoxazole/trimethoprim...

The pathogenicity of Stenotrophomonas maltophilia is regulated in part by its quorum sensing (QS) system. The main QS signaling molecule in S. maltophilia is known as diffusible signal factor (DSF), and the rpf gene cluster is responsible for its synthesis and perception. Two cluster variants have been previously described, rpf -1 and rpf -2, which differ basically in the conditions under which DSF is produced. Here, correlations between the rpf variant and antibiotic susceptibility, LPS electrophoretic profiles and virulence-related phenotypes were evaluated for a collection of 78 geographically and genetically diverse clinical strains of S...

BACKGROUND: Cefiderocol is a novel siderophore cephalosporin, developed for activity against MDR Gram-negative bacilli (MDR-GNB). OBJECTIVES: To assess the in vitro antibacterial activity of cefiderocol against a collection of MDR-GNB clinical isolates from hospitals in southern Spain. METHODS: Two hundred and thirty-one isolates of successful clones were tested: 125 Enterobacterales (121 ESBL- and/or carbapenemase-producing Klebsiella pneumoniae and 4 carbapenemase-producing Enterobacter cloacae), 80 Acinetobacter baumannii, 6 Pseudomonas aeruginosa and 20 Stenotrophomonas maltophilia...

BACKGROUND: POL7306 belongs to a new class of peptidomimetic outer-membrane-protein-targeting antibiotics with a novel mechanism of action. POL7306 is in development for the treatment of infections caused by antimicrobial-resistant Gram-negative bacteria and has demonstrated low cytotoxicity and nephrotoxicity. METHODS: A total of 891 isolates were collected by the SENTRY Antimicrobial Surveillance Program from 134 medical centres in Europe (n = 424; 41 centres in 18 nations), the USA (n = 411 isolates from 67 centres), the Asia-Pacific region (n = 24; 15 centres in 6 nations) and Latin America (n = 32; 11 centres in 9 nations) and included 558 Enterobacterales, 310 non-fermenters and 23 fastidious organisms...

Objectives: Stenotrophomonas maltophilia has emerged as an important opportunistic nosocomial pathogen due to its intrinsic and acquired resistance to a wide range of antimicrobial agents. The present study aimed to investigate the occurrence of antibiotic resistance and resistance mechanisms among clinical isolates of S. maltophilia from Iranian patients. Materials and Methods: This cross-sectional study was performed on 44 S. maltophilia isolates that were recovered from different clinical specimens in 2015 and 2016...

BACKGROUND: Levofloxacin has been considered as an alternative treatment for Stenotrophomonas maltophilia infection. However, levofloxacin-resistant S. maltophilia (LRSM) are emerging worldwide. AIM: To investigate LRSM risk factors in hospitalized patients and to determine antibiotic susceptibility patterns of LRSM isolates. METHODS: In a retrospective matched case-control-control study, LRSM patients (the case group) were compared with two control groups: levofloxacin-susceptible S...

Background: Since the 1980s, Stenotrophomonas maltophilia has emerged as an important pathogen associated with significant mortality in pneumonia and bacteremia of severely immunocompromised, hospitalized patients. The drug of choice in S maltophilia infections is sulfamethoxazole-trimethoprim (SMX/TMP); SMX/TMP resistance is a serious concern in clinical practice. The aim of this study was to assess the prevalence of S maltophilia in lower respiratory tract (LRTI) samples at a tertiary-care university hospital...

OBJECTIVE: Changes in the composition of the lung microbiome influence many lung diseases, including idiopathic pulmonary fibrosis (IPF), with a demonstrated association between the progression of IPF and the assessed pulmonary microbial community. A hypothesis to explain the pathogenesis of IPF is that an oxidant-antioxidant imbalance causes repeated epithelial cell injury and endogenous and exogenous antioxidants/redox modulators influence fibrogenesis, protect the lung against fibrosis, and prevent its progression...

Stenotrophomonas maltophilia is an emerging global opportunistic pathogen, responsible for a wide range of human infections, including respiratory tract infections. Intrinsic multidrug resistance and propensity to form biofilms make S. maltophilia infections recalcitrant to treatment. Colistin is among the second-line options in case of difficult-to-treat S. maltophilia infections, with the advantage of being also administrable by nebulization. We investigated the potential synergism of colistin in combination with N-acetylcysteine (NAC) (a mucolytic agent with antioxidant and anti-inflammatory properties) against S...

Stenotrophomonas maltophilia has been recognized as an emerging nosocomial pathogen in invasive infections of immunocompromised, severely debilitated patients with significant underlying illnesses. The first-choice drug in these infections is sulfamethoxazole-trimethoprim (SMX/TMP), and resistance to this antimicrobial is a daunting challenge for clinicians. The aim of this study was to assess the prevalence of S. maltophilia bacteremia and SMX/TMP-resistance levels at a tertiary-care university hospital. A total of 175 episodes of S...

Background: Acinetobacter calcoaceticus-A. baumannii ( Acb ) complex and Stenotrophomonas maltophilia represent frequent causes of hospital-acquired infections. We evaluated the frequency and resistance rates of Acb complex and S. maltophilia isolates from medical centers enrolled in the SENTRY Program. Methods: A total of 13 752 Acb complex and 6467 S. maltophilia isolates were forwarded to a monitoring laboratory by 259 participating sites from the Asia-Pacific region, Latin America, Europe, and North America between 1997 and 2016...

The polymyxin antibiotic colistin shows in vitro activity against Stenotrophomonas maltophilia . However, an increased incidence of colistin-resistant isolates has been recently observed. In addition, in vitro evaluation of colistin susceptibility for this organism has been problematic. The aims of this study were to investigate the colistin-resistance phenotypes displayed by S. maltophilia and their potential association with the challenging determination of colistin susceptibilities for this organism by even the recommended method...

Objectives: We investigated the in vitro activities of cefiderocol, ceftazidime/avibactam, ceftolozane/tazobactam and other related drugs against imipenem-resistant Pseudomonas aeruginosa, imipenem-resistant Acinetobacter baumannii and Stenotrophomonas maltophilia isolates. Methods: Non-duplicated bacteraemia isolates (n = 300) of imipenem-resistant P. aeruginosa (n = 100), imipenem-resistant A. baumannii (n = 100) and S. maltophilia (n = 100) were evaluated...

Non-fermenting Gram-negative bacteria (NFGNB) are increasingly cultured in respiratory samples from cystic fibrosis (CF) patients. This study determined the antimicrobial susceptibility of clinical CF respiratory isolates from distinct geographical regions. A total of 286 isolates (106 Stenotrophomonas maltophilia, 100 Burkholderia spp., 59 Achromobacter spp., 12 Pandoraea spp., 9 Ralstonia spp.) from the Netherlands, Northern Ireland, Spain, USA and Australia were tested. MIC50/90 values and susceptibility categorisation were determined...

Background: Treatment of infections in the ICU represents a great challenge, especially infections caused by Gram-negative organisms. Rapid introduction of appropriate antimicrobial therapy is crucial to reduce mortality, and resistance rates in the ICU can be elevated due to antimicrobial selection pressure. Objectives: To evaluate the frequency and antimicrobial susceptibility of Gram-negative bacteria isolated from patients with pneumonia hospitalized in ICUs...

OBJECTIVES: Pulmonary exacerbations in patients with cystic fibrosis (CF) caused by chronic Gram-negative bacterial infections are associated with reduced survival. These pathogens are usually treated with repeated courses of systemic antimicrobial agents. However, there is associated emergence of multidrug-resistant (MDR) pathogens. Ceftolozane/tazobactam (C/T) is a novel cephalosporin/β-lactamase inhibitor combination that has been demonstrated to have good activity against MDR Pseudomonas aeruginosa...

OBJECTIVES: The emergence of colistin resistance has been detected worldwide in recent years. Whilst colistin susceptibility has been tested in carbapenem resistant Enterobacteriaceae as well as multidrug-resistant Pseudomonas spp. and Acinetobacter spp. during routine laboratory practice, the overall rate of colistin resistance was unknown in our centre. The aim of this retrospective study was to reveal the prevalence of colistin resistance among clinically significant blood culture isolates in two different periods (2010-2011 and 2016) in our laboratory...

BACKGROUND: Recently, Stenotrophomonas maltophilia has increasingly been reported as an important nosocomial opportunistic pathogen. Limited therapeutic options of S. maltophilia infections demand early identification and knowledge about the probable risk factors for controlling its spread. STUDY DESIGN: The present study aimed to investigate the risk factors and trend of antibiotic susceptibility, along with genetic analysis in bacteraemia cases at pediatric intensive care units (PICUs)...