Pseudomonas aeruginosa populations in the cystic fibrosis lung lose susceptibility to newly applied β-lactams within 3 days

ConclusionsWe show that CF-associatedP. aeruginosa populations can quickly respond to antibiotic therapy and that responses are patient specific. Thus, resistance evolution can be a direct consequence of treatment, and drug efficacy can be lost much faster than usually assumed. The consideration of these patient-specific rapid resistance shifts can help to improve treatment of CF-associated infections, for example by deeper sampling of bacteria for diagnostics, repeated monitoring of pathogen susceptibility and switching between drugs.
Source: Journal of Antimicrobial Chemotherapy - Category: Microbiology Source Type: research

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Abstract Patient-derived isolates of the opportunistic pathogen Pseudomonas aeruginosa are frequently resistant to antibiotics due to the presence of sequence variants in resistance-associated genes. However, the frequency of antibiotic resistance and of resistance-associated sequence variants in environmental isolates of P. aeruginosa has not been well studied. Antimicrobial susceptibility testing (ciprofloxacin, ceftazidime, meropenem, tobramycin) of environmental (n=50) and cystic fibrosis (n=42) P. aeruginosa isolates was carried out. Following whole genome sequencing of all isolates, 25 resistance-associated ...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research
The development of therapies that modulate or prevent pathogen virulence may be a key strategy for circumventing antimicrobial resistance. Toward that end, we examined the production of pyoverdine, a key virulence determinant, in ~70 Pseudomonas aeruginosa isolates from pediatric cystic fibrosis patients. Pyoverdine production was heterogeneous and showed a clear correlation with pathogenicity in Caenorhabditis elegans and an acute murine pneumonia model. Examination showed pyoverdine accumulation in host tissues, including extrapharyngeal tissues of C. elegans and lung tissues of mice, where accumulation correlated with h...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Conclusion: Biofilm formation ability and relatively high frequency of exoS may contribute to the persistence of bacteria within lungs of CF patients. Some characteristics of isolates recovered from a single patient after several sampling procedures were similar, while others lacked resemblance. PMID: 31341563 [PubMed]
Source: Iranian Journal of Microbiology - Category: Microbiology Tags: Iran J Microbiol Source Type: research
Source: Journal of Cystic Fibrosis - Category: Respiratory Medicine Authors: Tags: Orals Sessions Source Type: research
Source: Journal of Cystic Fibrosis - Category: Respiratory Medicine Authors: Tags: Posters Sessions Source Type: research
In this study, the full-length PcrV was divided into four domains with the guidance of its structure, and the Nter domain (Met1-Lys127) and H12 domain (Leu251-Ile294) were found to be immunodominant. Subsequently, Nter and H12 were combined with a flexible linker to generate an artificial PcrV derivative (PcrVNH). PcrVNH was successfully produced in E. coli and behaved as a homogenous monomer. Moreover, immunization with PcrVNH elicited a multifactorial immune response and conferred broad protection in an acute PA pneumonia model and was equally effective to full-length PcrV. In addition, passive immunization with anti-Pcr...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
ConclusionEvaluation of hypersusceptible mutants identified the association betweenlptG and a hypersusceptible phenotype. Modifications in lipopolysaccharide profiles suggests LptG modification interferes with lipopolysaccharide transport and contributes to hypersusceptibility.
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: SPECIAL ISSUE: ANTIMICROBIAL RESISTANCE Source Type: research
Raquel Ferrer-Espada1,2, Xiaojing Liu1,2, Xueping Sharon Goh1,2 and Tianhong Dai1,2* 1Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States 2Vaccine &Immunotherapy Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States Polymicrobial biofilms, in which mixed microbial species are present, play a significant role in persistent infections. Furthermore, polymicrobial biofilms promote antibiotic resistance by allowing interspecies transfer of antibiotic resistance genes. In the present study, we investigated the effec...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Antimicrobial susceptibility testing (AST) is a mainstay in the management of cystic fibrosis (CF) bacterial lung infections (both acute and chronic), although more recently its clinical utility in CF has come into question [1]. In this issue of JCF, Somayaji et al., on behalf of the Antimicrobial Resistance in CF Working Group, performed a thoughtful and thorough systematic review of published studies on AST in CF and its association with clinical response [2]. This systematic review, which included a mixture of retrospective and prospective observational studies as well as randomized controlled trials, utilized the PICO ...
Source: Journal of Cystic Fibrosis - Category: Respiratory Medicine Authors: Tags: Editorial Source Type: research
Antimicrobial susceptibility testing (AST) is a cornerstone of infection management. Cystic fibrosis (CF) treatment guidelines recommend AST to select antimicrobial treatments for CF airway infection but its utility in this setting has never been objectively demonstrated.
Source: Journal of Cystic Fibrosis - Category: Respiratory Medicine Authors: Tags: Original Article Source Type: research
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