scholarly journals Effects of reducing beta-lactam antibiotic pressure on intestinal colonization of antibiotic-resistant gram-negative bacteria

2009 ◽  
Vol 36 (3) ◽  
pp. 512-519 ◽  
Author(s):  
Saskia Nijssen ◽  
Ad Fluit ◽  
David van de Vijver ◽  
Janetta Top ◽  
Rob Willems ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Intestinal Colonization ◽  
Beta Lactam ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Beta Lactam Antibiotic ◽  
Lactam Antibiotic

scholarly journals Colonization With Antibiotic-Resistant Gram-Negative Bacteria in Population-Based Hospital and Community Settings in Chile

2020 ◽  
Vol 41 (S1) ◽  
pp. s175-s176
Author(s):  
Rafael Araos Bralic ◽  
Anne Peters ◽  
Felipe Sanchez ◽  
Danilo Alvares ◽  
Lina Rivas ◽  
...  
Keyword(s):  
Risk Factors ◽  
Community Setting ◽  
Population Based ◽  
Community Dwelling ◽  
Gram Negative Bacteria ◽  
Intestinal Colonization ◽  
Community Settings ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
High Burden

Background: Estimating the burden of intestinal colonization with antibiotic-resistant gram-negative bacteria (AR-GNB) is critical to understanding their global epidemiology and spread. We aimed to determine the prevalence of, and risk factors for, intestinal colonization due to AR-GNB in population-based hospital and community settings in Chile. Methods: Between December 2018 and May 2019, we enrolled randomly selected hospitalized adults in 4 tertiary-care public hospitals (Antofagasta, Santiago, Curico and Puerto Montt), and adults residing in a community-based cohort in the rural town of Molina. Following informed consent, we collected rectal swabs and epidemiological information through a standardized questionnaire. Swabs were plated onto MacConkey agar with 2 µg/mL ciprofloxacin or ceftazidime. All recovered morphotypes were identified, and antibiotic susceptibility testing was performed via disk diffusion. The primary outcome was the prevalence of colonization with fluoroquinolone (FQ)- or third-generation cephalosporin (3GC)–resistant GNB. The secondary outcome was the prevalence of colonization with multidrug-resistant (MDR) GNB, defined as GNB resistant to ≥3 antibiotic classes. Categories were not mutually exclusive. Bivariate and multivariate analyses were performed to describe risk factors for colonization with these categories. Results: In total, 775 hospitalized adults and 357 community participants were enrolled, with a median age of 60 years (IQR, 42–72) and 55 years (IQR, 48–62) years, respectively. Among hospitalized participants, the prevalence of colonization with FQ- or 3GC-resistant GNB was 47% (95% CI, 43%–50%) and 41% (95% CI, 38%–45%), respectively, whereas the prevalence of MDR-GNB colonization was 27% (95% CI, 24%–31%). In the community setting, the prevalence of colonization with either FQ-, 3GC-resistant GNB, or MDR-GNB was 40% (95% CI, 34%–45%), 29% (95% CI, 24%– 34%), and 5% (95% CI, 3%–8%), respectively. Independent risk factors for hospital MDR-GNB colonization included the hospital of admission, unit of hospitalization (intensive care units carried the highest risk), in-hospital antimicrobial exposure, comorbidities (Charlson index), and length of stay. In the community setting, recent antibiotic exposure (<3 months) predicted colonization with either FQ- or 3GC-resistant GNB, and alcohol consumption was inversely associated with MDR GNB colonization. Conclusions: A high burden of colonization with AR-GNB was observed in this sample of hospitalized and community-dwelling adults in Chile. The high burden of colonization with GNB resistant to commonly used antibiotics such as FQ and 3GC found in community dwellers, suggests that the community may be a relevant source of antibiotic resistance. Efforts to understand relatedness between resistant strains circulating in the community and the hospital are needed.Funding: NoneDisclosures: None

scholarly journals The time course of hydrolysis of a β-lactam antibiotic by intact gram-negative bacteria possessing a periplasmic β-lactamase

1987 ◽  
Vol 244 (3) ◽  
pp. 509-513 ◽  
Author(s):  
W W Nichols
Keyword(s):  
Time Course ◽  
Decay Constant ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Beta Lactam ◽  
Intact Cells ◽  
Gram Negative ◽  
First Order ◽  
Lactam Antibiotic ◽  
Hydrolysis Of

An equation is derived from first principles for describing the change in concentration with time of a beta-lactam antibiotic in the presence of intact Gram-negative bacteria possessing a beta-lactamase located in the periplasmic space. The equation predicts a first-order decline in beta-lactam concentration of the form [S] = [Si]e lambda t, where [S] is the exogenous concentration of beta-lactam, [Si] is the value of [S] at time zero, t is the time from mixing of cells and antibiotic and lambda (less than 0) is the decay constant. The value of lambda is exactly described by the theory in terms of experimentally measurable quantities. Quantitative data concerning cephaloridine hydrolysis by intact cells of Haemophilus influenzae agreed well with the theory, as did data concerning the uptake of 2-nitrophenyl galactoside by intact cells of Escherichia coli. Cephalosporin C hydrolysis by intact cells of Pseudomonas aeruginosa did not progress as predicted by the theory. The theory is applicable to any substrate which is acted on by an enzyme that is located solely in the periplasmic space and that obeys the Michaelis-Menten equation of enzyme kinetics.

scholarly journals OMN6 a novel bioengineered peptide for the treatment of multidrug resistant Gram negative bacteria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shira Mandel ◽  
Janna Michaeli ◽  
Noa Nur ◽  
Isabelle Erbetti ◽  
Jonathan Zazoun ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Antimicrobial Agents ◽  
Cyclic Peptide ◽  
Safety Margin ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Development Of Resistance ◽  
Cecropin A

AbstractNew antimicrobial agents are urgently needed, especially to eliminate multidrug resistant Gram-negative bacteria that stand for most antibiotic-resistant threats. In the following study, we present superior properties of an engineered antimicrobial peptide, OMN6, a 40-amino acid cyclic peptide based on Cecropin A, that presents high efficacy against Gram-negative bacteria with a bactericidal mechanism of action. The target of OMN6 is assumed to be the bacterial membrane in contrast to small molecule-based agents which bind to a specific enzyme or bacterial site. Moreover, OMN6 mechanism of action is effective on Acinetobacter baumannii laboratory strains and clinical isolates, regardless of the bacteria genotype or resistance-phenotype, thus, is by orders-of-magnitude, less likely for mutation-driven development of resistance, recrudescence, or tolerance. OMN6 displays an increase in stability and a significant decrease in proteolytic degradation with full safety margin on erythrocytes and HEK293T cells. Taken together, these results strongly suggest that OMN6 is an efficient, stable, and non-toxic novel antimicrobial agent with the potential to become a therapy for humans.

scholarly journals Effect of a bacterial lipopolysaccharide on biliary excretion of a beta- lactam antibiotic, cefoperazone, in rats

1995 ◽  
Vol 39 (10) ◽  
pp. 2258-2261 ◽  
Author(s):  
S. Haghgoo ◽  
T. Hasegawa ◽  
M. Nadai ◽  
L. Wang ◽  
T. Nabeshima ◽  
...  
Keyword(s):  
Biliary Excretion ◽  
Bacterial Lipopolysaccharide ◽  
Beta Lactam ◽  
Beta Lactam Antibiotic ◽  
Lactam Antibiotic
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