Sensitivity of 341 non-fermentative gram-negative bacteria to seven beta-lactam antibiotics

1982 ◽  
Vol 1 (3) ◽  
pp. 159-165 ◽  
Author(s):  
P. C. Appelbaum ◽  
J. Tamim ◽  
J. Stavitz ◽  
R. C. Aber ◽  
G. A. Pankuch
Keyword(s):  
Gram Negative Bacteria ◽  
Beta Lactam ◽  
Gram Negative ◽  
Beta Lactam Antibiotics

scholarly journals Combination antibiotic therapy versus monotherapy in the treatment of acute exacerbations of chronic obstructive pulmonary disease: an open-label randomized trial

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Phuong Nguyen Thi Thu ◽  
Minh Ngo Thị Huong ◽  
Ngan Tran Thi ◽  
Hoi Nguyen Thanh ◽  
Khue Pham Minh
Keyword(s):  
Clinical Success ◽  
Chronic Obstructive ◽  
Gram Negative Bacteria ◽  
Beta Lactam ◽  
Open Label ◽  
Obstructive Pulmonary Disease ◽  
Gram Negative ◽  
Copd Exacerbations ◽  
Beta Lactam Antibiotics ◽  
Acute Exacerbations

Abstract Background The role of antibiotics in the treatment of chronic obstructive pulmonary disease (COPD) exacerbations and their effectiveness in combination have not been clearly established. To determine whether using a combination of fluoroquinolones and beta-lactams improves the clinical and microbiological efficacy of antibiotics on day 20 of treatment, we conducted an open-label randomized trial based on clinical outcomes, microbiological clearance, spirometry tests, and signs of systemic inflammation in patients hospitalized with acute exacerbations of COPD. Methods We enrolled 139 subjects with COPD exacerbations, defined as acute worsening of respiratory symptoms leading to additional treatment. Patients were divided randomly into two groups: 79 patients using beta-lactam antibiotics alone and 60 using beta-lactam antibiotics plus fluoroquinolones. Clinical and microbiological responses, spirometry tests, symptom scores, and serum C-reactive protein (CRP) levels were evaluated. Results Clinical success, lung function, and symptoms were similar in patients with or without fluoroquinolone administration on days 10 and 20. Combination therapy was superior in terms of microbiological outcomes and reduction in serum CRP value. Although equivalent to monotherapy in terms of clinical success, the combination showed superiority in terms of microbiological success and a decrease in CRP. The combination therapy group had a higher microbiological success rate with gram-negative bacteria than the monotherapy group with Pseudomonas aeruginosa (100% vs. 33.3%, respectively) and Acinetobacter baumanii (100% vs. 20%, respectively) (P < 0.05). Conclusions Concomitant use of fluoroquinolone and beta-lactam antibiotics for bacterial infections during COPD exacerbations caused by gram-negative bacteria appear to be effective and should be applied in clinical practice.

scholarly journals Clinical Relevance of Antibiotic Susceptibility Profiles for Screening Gram-negative Microorganisms Resistant to Beta-Lactam Antibiotics

2020 ◽  
Vol 8 (10) ◽  
pp. 1555 ◽  
Author(s):  
Francisco Montiel-Riquelme ◽  
Elisabeth Calatrava-Hernández ◽  
Miguel Gutiérrez-Soto ◽  
Manuela Expósito-Ruiz ◽  
José María Navarro-Marí ◽  
...  
Keyword(s):  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Gram Negative ◽  
Extended Spectrum Beta Lactamase ◽  
Beta Lactam Antibiotics ◽  
Clinical Laboratories ◽  
Phenotypic Methods ◽  
Susceptibility Profiles

The increasing resistance to antibiotics is compromising the empirical treatment of infections caused by resistant bacteria. Rapid, efficient, and clinically applicable phenotypic methods are needed for their detection. This study examines the phenotypic behavior of β-lactam-resistant Gram-negative bacteria grown on ChromID ESBL medium with ertapenem, cefoxitin, and cefepime disks, reports on the coloration of colonies, and establishes a halo diameter breakpoint for the detection of carbapenemase-producing bacteria. We studied 186 β-lactam-resistant Gram-negative microorganisms (77 with extended spectrum beta lactamase (ESBL), 97 with carbapenemases, and 12 with AmpC β-lactamases (AmpC)). Susceptibility profiles of Gram-negative bacteria that produced ESBL, AmpC, and carbapenemases were similar to the expected profiles, with some differences in the response to cefepime of ESBL-producing microorganisms. Coloration values did not differ from those described by the manufacturer of ChromID ESBL medium. In the screening of carbapenemase production, inhibition halo diameter breakpoints for antibiotic resistance were 18 mm for Enterobacterales and ertapenem, 18 mm for Pseudomonas and cefepime, and 16 mm for Acinetobacter baumannii and cefepime. This innovative phenotypic approach is highly relevant to clinical laboratories, combining susceptibility profiles with detection by coloration of high-priority resistant microorganisms such as carbapenemase-producing A. baumannii, carbapenemase-producing Pseudomonas spp., and ESBL and/or carbapenemase-producing Enterobacterales.

scholarly journals In vitro evaluation of BO-3482, a novel dithiocarbamate carbapenem with activity against methicillin-resistant staphylococci.

1997 ◽  
Vol 41 (10) ◽  
pp. 2282-2285 ◽  
Author(s):  
Y Adachi ◽  
K Nakamura ◽  
Y Kato ◽  
N Hazumi ◽  
T Hashizume ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clostridium Difficile ◽  
Proteus Mirabilis ◽  
Gram Negative Bacteria ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Beta Lactam Antibiotics

BO-3482, a dithiocarbamate carbapenem, inhibited clinical isolates of methicillin-resistant staphylococci (MRS) at 6.25 microg/ml (MIC at which 90% of isolates tested are inhibited [MIC90]), while the MIC90 of imipenem was > 100 microg/ml. BO-3482 was generally less active than imipenem against methicillin-susceptible Staphylococcus aureus, streptococci, enterococci, and gram-negative bacteria, although BO-3482 showed better activity (MIC90) than imipenem against Enterococcus faecium, Haemophilus influenzae, Proteus mirabilis, and Clostridium difficile. The affinities (50% inhibitory concentrations) of BO-3482 for penicillin-binding protein (PBP) PBP 2' of MRS and PBP 5 of E. faecium (both PBPs have low affinities for ordinary beta-lactam antibiotics) were 3.8 and 20 microg/ml, respectively, reflecting the greater activity of BO-3482 against MRS than against E. faecium.

Characterization of eight beta-lactamases of Gram-negative bacteria

1982 ◽  
Vol 152 (2) ◽  
pp. 567-571
Author(s):  
T Sawai ◽  
M Kanno ◽  
K Tsukamoto
Keyword(s):  
Assay Method ◽  
Gram Negative Bacteria ◽  
Beta Lactam ◽  
Ph Optimum ◽  
Gram Negative ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
R Plasmids ◽  
Ph Stat ◽  
Species Specific

Eight kinds of beta-lactamases produced by gram-negative bacteria were characterized by the following properties: molecular weight, isoelectric point, pH optimum, molecular activity, immunochemical reactivity, and kinetic parameters with respect to twelve kinds of common beta-lactam antibiotics. These beta-lactamases included two types of penicillinases mediated by R plasmids and six kinds of species-specific cephalosporinases. To determine a reliable value of the kinetic parameter, Km, we introduced a continuous and acidimetric assay method of beta-lactamase activity with a pH stat.

scholarly journals Monitoring of gram-negative bacteria and antibiotic resistance in osteomyelitis

2020 ◽  
Vol 26 (4) ◽  
pp. 544-547
Author(s):  
I.V. Shipitsyna ◽  
◽  
E.V Osipova ◽  
D.S. Leonchuk ◽  
A.S. Sudnitsyn ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Clinical Isolates ◽  
Gram Negative Bacteria ◽  
Beta Lactam ◽  
Gram Negative ◽  
Regular Monitoring ◽  
Beta Lactam Antibiotics ◽  
Bacterial Morphology ◽  
Acinetobacter Sp ◽  
Drug Resistant Strains

Introduction There is an urgent need for a surveillance system of regular monitoring of specific bacteria inducing various types of osteomyelitis to identify resistant isolates and optimize the use of antibiotics. Objective: monitoring of specific gram-negative bacteria and analysis of the antibiotic resistance of the strains isolated from osteomyelitis patients over a three-year period. Results and discussion P. aeruginosa was the first most common pathogen among gram-negative microorganisms isolated from the patients between 2017 and 2019. Prevalence of the isolates identified in 2019 decreased by 9.6 % as compared to 2017. Next frequently encountered clinical isolates were Enterobacter sp., Acinetobacter sp., Klebsiella sp. There was a twofold increase in K. pneumoniae strains isolated in 2019. Analysis of antibiotic susceptibility testing data revealed multiresistance of the Acinetobacter sp. strains in 2019 despite the total decrease in resistant isolates in 2017 and 2018. Among non-fermenting gram-negative rods, the species being resistant to imipenem were shown to increase by 5.4 times. Overall antibiotic resistance was on rise. Increased antimicrobial resistance to beta-lactam antibiotics also combined with BLaC inhibitors was observed in Enterobacteriaceae population. Meropenem was found to be effective against most bacteria with growing drug resistance observed as compared with recent years. The antibiotic resistance profiles of Klebsiella sp. strains appeared to be high at antimicrobial testing. Conclusion Diverse bacterial morphology of gram-negative species and increasing proportion of drug-resistant strains isolated in osteomyelitis cases have necessitated regular monitoring of multiresistant clinical isolates for adjustment of empirical antibiotic therapies.

Detection of Escherichia coli O157:H7 and Salmonella enterica serotype Typhimurium based on cell elongation induced by beta-lactam antibiotics

The Analyst ◽  
2019 ◽  
Vol 144 (15) ◽  
pp. 4505-4512 ◽  
Author(s):  
Min Jia ◽  
Zhaochen Liu ◽  
Chuanchen Wu ◽  
Zhen Zhang ◽  
Luyao Ma ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Elongation ◽  
Membrane Filtration ◽  
Detection Method ◽  
Bacteria Detection ◽  
Escherichia Coli O157 ◽  
Gram Negative Bacteria ◽  
Beta Lactam ◽  
Gram Negative ◽  
Beta Lactam Antibiotics

A novel Gram-negative bacteria detection method based on cell elongation combined with membrane filtration and magnetic separation was established.

scholarly journals Identification of MupP as a New Peptidoglycan Recycling Factor and Antibiotic Resistance Determinant in Pseudomonas aeruginosa

mBio ◽  
2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Coralie Fumeaux ◽  
Thomas G. Bernhardt
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Opportunistic Pathogen ◽  
Gram Negative Bacteria ◽  
Beta Lactam ◽  
Gram Negative ◽  
Beta Lactam Antibiotics ◽  
Cell Wall Biogenesis ◽  
Cell Wall Recycling

ABSTRACT Peptidoglycan (PG) is an essential cross-linked polymer that surrounds most bacterial cells to prevent osmotic rupture of the cytoplasmic membrane. Its synthesis relies on penicillin-binding proteins, the targets of beta-lactam antibiotics. Many Gram-negative bacteria, including the opportunistic pathogen Pseudomonas aeruginosa, are resistant to beta-lactams because of a chromosomally encoded beta-lactamase called AmpC. In P. aeruginosa, expression of the ampC gene is tightly regulated and its induction is linked to cell wall stress. We reasoned that a reporter gene fusion to the ampC promoter would allow us to identify mutants defective in maintaining cell wall homeostasis and thereby uncover new factors involved in the process. A library of transposon-mutagenized P. aeruginosa was therefore screened for mutants with elevated ampC promoter activity. As an indication that the screen was working as expected, mutants with transposons disrupting the dacB gene were isolated. Defects in DacB have previously been implicated in ampC induction and clinical resistance to beta-lactam antibiotics. The screen also uncovered murU and PA3172 mutants that, upon further characterization, displayed nearly identical drug resistance and sensitivity profiles. We present genetic evidence that PA3172, renamed mupP, encodes the missing phosphatase predicted to function in the MurU PG recycling pathway that is widely distributed among Gram-negative bacteria. IMPORTANCE The cell wall biogenesis pathway is the target of many of our best antibiotics, including penicillin and related beta-lactam drugs. Resistance to these therapies is on the rise, particularly among Gram-negative species like Pseudomonas aeruginosa, a problematic opportunistic pathogen. To better understand how these organisms resist cell wall-targeting antibiotics, we screened for P. aeruginosa mutants defective in maintaining cell wall homeostasis. The screen identified a new factor, called MupP, involved in the recycling of cell wall turnover products. Characterization of MupP and other components of the pathway revealed that cell wall recycling plays important roles in both the resistance and the sensitivity of P. aeruginosa to cell wall-targeting antibiotics. IMPORTANCE The cell wall biogenesis pathway is the target of many of our best antibiotics, including penicillin and related beta-lactam drugs. Resistance to these therapies is on the rise, particularly among Gram-negative species like Pseudomonas aeruginosa, a problematic opportunistic pathogen. To better understand how these organisms resist cell wall-targeting antibiotics, we screened for P. aeruginosa mutants defective in maintaining cell wall homeostasis. The screen identified a new factor, called MupP, involved in the recycling of cell wall turnover products. Characterization of MupP and other components of the pathway revealed that cell wall recycling plays important roles in both the resistance and the sensitivity of P. aeruginosa to cell wall-targeting antibiotics.

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