Interaction in vitro entre l'association ampicilline–colistine et Escherichia coli resistant à l'ampicilline

1983 ◽  
Vol 29 (12) ◽  
pp. 1650-1652
Author(s):  
M. Coste ◽  
L. Escoula
Keyword(s):  
Escherichia Coli ◽  
Proteus Mirabilis ◽  
Lower Layer ◽  
Superficial Layer ◽  
Beta Lactamases ◽  
E Coli ◽  
Agar Media ◽  
Potential Interactions

In this work, the authors studied in vitro potential interactions between bacteria and antibiotics. Colistin and ampicillin were introduced to ampicillin-resistant Escherichia coli and ampicillin activity was measured. Two layers of agar media were used. The lower layer contained E. coli and colistin. The superficial layer was sown with indicating bacteria (ampicillin-sensitive Proteus mirabilis). Ampicillin activity was evaluated on the upper layer with impregnated disks. By this technique, it was ascertained that ampicillin degradation increased with colistin concentration. In this case, colistin may favour interactions of intracellular beta-lactamases on ampicillin.

scholarly journals Inhibitory Effect of Methanolic and Methanolic-Aqueous Mixture Extract of Leaves of Plectranthus neochilus Schltr (Lamiaceae) and Bauhinia rufescens Lam (Fabaceae) on Two Strains of Enterobacteria Producing Beta-lactamases

2020 ◽  
pp. 11-20
Author(s):  
Mamoudou Hamadou ◽  
Bakari Daoudou ◽  
Baane Martin- Paul ◽  
Salamatou Mohamadou ◽  
Djoulde Darman Roger
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Proteus Mirabilis ◽  
Inhibitory Effect ◽  
Beta Lactams ◽  
Beta Lactamases ◽  
Aqueous Mixture ◽  
Almost All ◽  
Multiresistant Strain

The objective of the study was to evaluate in vitro inhibitory effect of methanolic and methanolic-aqueous mixture extracts of Plectranthus neochilus Schltr (P. neochilus) and Bauhinia rufescens Lam (B. rufescens) on the growth of Escherichia coli 25922 and Proteus mirabilis. A phytochemical screening was carried out to highlight compounds (phenolic compounds, flavonoids, alkaloids) with antibacterial activity. Then, an antibiogram was Carried out to investigate the enzymes rendering the resistance. Finally, the E-test was used to evaluate the antibacterial activity of the extract mixture. The Screening results showed that both plants contain total phenolics, flavonoids and alkaloids compounds. The antibiogram has made it possible to establish the sensitivity profile of the strains tested with regard to certain antibiotics. The extract mixture showed antibacterial activity on both strains tested. In the present work, the different mixtures of extracts showed an inhibitory effect on Escherichia coli 25922 [a strain sensitive to almost all the antibiotics tested, in particular the three classes: beta-lactams (Ceftazidine, Ceftriaxone, Meropenem), quinolones (Levofloxacin, Ciprofloxacin) and aminoglycosides (Gentamicin, Amikacin)] and on Proteus mirabilis (a multiresistant strain with almost all the antibiotics tested).

scholarly journals Occurrence and Detection of AmpC Beta-Lactamases among Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis Isolates at a Veterans Medical Center

2000 ◽  
Vol 38 (5) ◽  
pp. 1791-1796 ◽  
Author(s):  
Philip E. Coudron ◽  
Ellen S. Moland ◽  
Kenneth S. Thomson
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Isoelectric Focusing ◽  
Proteus Mirabilis ◽  
Medical Center ◽  
Three Dimensional ◽  
Beta Lactamase ◽  
True Rate ◽  
Beta Lactamases ◽  
E Coli

AmpC beta-lactamases are cephalosporinases that confer resistance to a wide variety of β-lactam drugs and that may thereby create serious therapeutic problems. Although reported with increasing frequency, the true rate of occurrence of AmpC beta-lactamases inEscherichia coli, Klebsiella pneumoniae, andProteus mirabilis remains unknown. We tested a total of 1,286 consecutive, nonrepeat isolates of these three species and found that, overall, 45 (3.5%) yielded a cefoxitin zone diameter less than 18 mm (screen positive) and that 16 (1.2%) demonstrated AmpC bands by isoelectric focusing. Based on the species, of 683 E. coli, 371 K. pneumoniae, and 232 P. mirabilisisolates tested, 13 (1.9%), 28 (7.6%), and 4 (1.7%), respectively, demonstrated decreased zone diameters and 11 (1.6%), 4 (1.1%), and 1 (0.4%), respectively, demonstrated AmpC bands. Cefoxitin resistance was transferred for all but 8 (E. coli) of the 16 AmpC producers. We also describe a three-dimensional extract test, which was used to detect phenotypically isolates that harbor AmpC beta-lactamase. Of the 45 cefoxitin-resistant isolates, the three-dimensional extract test accurately identified all 16 AmpC producers and 28 of 29 (97%) isolates as non-AmpC producers. Interestingly, most (86%) isolates in the latter group were K. pneumoniae isolates. These data confirm that, at our institution, E. coli, K. pneumoniae, and P. mirabilis harbor plasmid-mediated AmpC enzymes.

scholarly journals Infecções comunitárias do trato urinário: prevalência e susceptibilidade aos antimicrobianos na cidade de Florianópolis

2016 ◽  
Vol 11 (38) ◽  
pp. 1-12 ◽  
Author(s):  
Débora Monteiro dos Santos Alves ◽  
Marcos Krahe Edelweiss ◽  
Lúcio José Botelho
Keyword(s):  
Escherichia Coli ◽  
Proteus Mirabilis ◽  
E Coli

Objetivo: Determinar a frequência de isolamento dos uropatógenos e avaliar o perfil de sensibilidade antimicrobiana in vitro das bactérias isoladas em uroculturas de pacientes ambulatoriais atendidos em Florianópolis no ano de 2014, correlacionando tais dados com sexo e idade do paciente. Métodos: Estudo observacional, descritivo do tipo transversal, que incluiu uroculturas positivas de pacientes ambulatoriais realizadas em um único laboratório seguindo a mesma metodologia. Realizaram-se análises de estatísticas descritivas e testes de associação entre as variáveis classificatórias: sexo, idade, agente etiológico e sensibilidade aos antimicrobianos. Resultados: Foram registradas 1035 uroculturas positivas, das quais 89,66% de pacientes femininas. Microrganismos Gram-negativos foram os patógenos mais isolados, com destaque para a Escherichia coli (77,10%), principal agente causal. Proteus mirabilis foi significativamente mais prevalente no sexo masculino e o principal microrganismo isolado nas uroculturas dos meninos de 1 a 5 anos. A E. coli foi significativamente mais prevalente no sexo feminino e apresentou o perfil mais amplo de resistência. Evidenciaram-se diferenças estatisticamente significativas nas resistências às fluoroquinolonas entre os gêneros, com maiores prevalências de resistência em homens e entre as faixas etárias, com maior resistência entre idosos. Conclusões: Idade e sexo são variáveis determinantes na frequência de isolamento dos uropatógenos e na prevalência da susceptibilidade antimicrobiana; e os microrganismos mais prevalentes já não respondem satisfatoriamente a parte dos antimicrobianos amplamente utilizados. É fundamental que o médico considere tais informações no momento da decisão terapêutica e preze pelo uso racional dos antimicrobianos, sobretudo aqueles de largo espectro como as fluoroquinolonas.

scholarly journals Susceptibilidade Antimicrobiana de Bactérias Ocorrentes em Úlceras Crônicas aos Extratos Brutoss de Prosopis Juliflora

2015 ◽  
Vol 8 (3) ◽  
pp. 493
Author(s):  
Renata Soares Da Silva ◽  
Karla Maria Santos De Oliveira ◽  
Giani Maria Cavalcante
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Proteus Mirabilis ◽  
Prosopis Juliflora ◽  
E Coli

Úlceras crônicas são suscetíveis à infecção devido à perda estéril da função de barreira inata da pele e dos anexos cutâneos, facilitando o desenvolvimento de comunidades microbianas. O objetivo do estudo foi investigar a suscetibilidade de bactérias associadas a úlceras crônicas aos extratos brutos de Prosopis juliflora. Os testes in vitro foram realizados com extratos brutos das folhas e casca do caule contra as estirpes de Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923) e Proteus mirabilis (ATCC 7002), por meio de ensaio de difusão em agar com poço e determinação da Concentrações Inibitórias Mínimas (MIC). Os resultados mostraram que as estirpes de E. coli, P. aeruginosa, S. aureus e P. mirabilis foram mais susceptíveis aos extratos brutos da folha, com diâmetro de zona de inibição de 21,0; 33,0; 20,0; 21,0 mm, respectivamente, enquanto, E. coli e S. aureus foram mais susceptíveis aos extratos brutos da casca do caule, com diâmetro da zona de inibição de 21,5 e 20,0 mm, respectivamente. Os melhores valores de CIM foram registrados para EBF de P. juliflora. Estudo químico para a extração e o isolamento de compostos ativos é recomendado para realização de ensaios in vitro para investigar a atividade antimicrobiana destes compostos.

scholarly journals In vitro and in vivo efficacy study of cefepime, doripenem, tigecycline, and tetracycline against extended-spectrum beta-lactamases Escherichia coli in chickens

2020 ◽  
Vol 13 (3) ◽  
pp. 446-451
Author(s):  
Yaser Hamadeh Tarazi ◽  
Ehab A. Abu-Basha ◽  
Zuhair Bani Ismail ◽  
Rawan A. Tailony
Keyword(s):  
Escherichia Coli ◽  
Clinical Signs ◽  
Control Group ◽  
In Vivo Efficacy ◽  
Beta Lactamases ◽  
E Coli ◽  
Extended Spectrum Beta Lactamases ◽  
Gross Lesions

Background and Aim: At present, there are no data about the efficacy of some recent antibiotics on Escherichia coli in broiler chickens in the study area. This study was designed to evaluate the in vitro and in vivo efficacy of cefepime, doripenem, tigecycline, and tetracycline against multidrug-resistant-extended-spectrum beta-lactamases (MDR-ESBLs) producing E. coli in broiler chicks. Materials and Methods: A total of 34 MDR-ESBLs E. coli isolates were used in this study. In vitro evaluation of the antibacterial efficacy of cefepime, doripenem, tigecycline, and tetracycline were performed using disk diffusion and minimum inhibitory concentration (MIC) assays. In vivo evaluation of the efficacy of the antibiotics was perfumed using 180, 2-week-old chicks challenged with MDR-ESBL-producing E. coli strain O78. Chicks were divided into six groups (30 chicks each) according to the treatment regimen. Treatment was administered to chicks in Groups 3-6 intravenously, twice per day for 1 week using one antibiotic per group at concentration 10 times the determined MIC. Chicks in the positive control (Group 1) were challenged and received 0.2 ml of sterile Tryptone Soy Broth (TSB), while those in the negative control (Group 2) were not challenged and received 0.2 ml of sterile TSB. The severity of clinical signs, gross lesions, and mortality rate was scored and compared between groups. Results: All E. coli isolates were sensitive to doripenem and tigecycline, while 88% were sensitive to cefepime and only 23% were sensitive to tetracycline. In vivo antibiotic efficacy evaluation in challenged chicks revealed a significant reduction in the severity of clinical signs, gross lesions, and mortality (3%) in chicks treated with cefepime compared to non-treated chicks (55%). There was no significant effect on the severity of clinical signs, gross lesions, and mortality in chicks treated with doripenem, tigecycline, and tetracycline compared to non-treated chicks. The mortality rates of chicks treated with doripenem, tigecycline, and tetracycline were 57%, 50%, and 90%, respectively. Conclusion: The results of this study indicate that most MDR-ESBLs producing E. coli isolates were sensitive to doripenem, tigecycline, and cefepime. However, in vivo study indicated that only cefepime was effective and resulted in a significant reduction in clinical signs, gross lesions, and mortality in infected chicks. Therefore, cefepime could be used to treat naturally infected chickens with MDR-ESBLs producing strains of E. coli.

scholarly journals Definitive Cefazolin Therapy for Stabilized Adults with Community-Onset Escherichia coli, Klebsiella Species, and Proteus mirabilis Bacteremia: MIC Matters

2020 ◽  
Vol 9 (1) ◽  
pp. 157 ◽  
Author(s):  
Chih-Chia Hsieh ◽  
Po-Lin Chen ◽  
Chung-Hsun Lee ◽  
Chao-Yung Yang ◽  
Ching-Chi Lee ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Treatment Failure ◽  
Proteus Mirabilis ◽  
Primary Treatment ◽  
Klebsiella Species ◽  
E Coli ◽  
Crude Mortality ◽  
Definitive Therapy ◽  
Community Onset

Background: Cefazolin is in vitro active against wild isolates of Escherichia coli, Klebsiella species, and Proteus mirabilis (EKP), but clinical evidence supporting the contemporary susceptibility breakpoint issued by the Clinical and Laboratory Standards Institute (CLSI) are limited. Methods: Between 2010 and 2015, adults with monomicrobial community-onset EKP bacteremia with definitive cefazolin treatment (DCT) at two hospitals were analyzed. Cefazolin minimum inhibitory concentrations (MICs) were correlated with clinical outcomes, including primary (treatment failure of DCT) and secondary (30-day mortality after bacteremia onset, recurrent bacteremia, and mortality within 90 days after the end of DCT) outcomes. Results: Overall, 466 bacteremic episodes, including 340 (76.2%) episodes due to E. coli, 90 (20.2%) Klebsiella species, and 16 (3.6%) P. mirabilis isolates, were analyzed. The mean age of these patients was 67.8 years and female-predominated (68.4%). A crude 15- and 30-day mortality rate was 0.7% and 2.2%, respectively, and 11.2% experienced treatment failure of DCT. A significant linear-by-linear association of cefazolin MICs, with the rate of treatment failure, 30-day crude mortality, recurrent bacteremia or 90-day mortality after the DCT was present (all γ = 1.00, p = 0.01). After adjustment, the significant impact of cefazolin MIC breakpoint on treatment failure and 30-day crude mortality was most evident in 2 mg/L (>2 mg/L vs. ≤2 mg/L; adjusted hazard ratio, 3.69 and 4.79; p < 0.001 and 0.02, respectively). Conclusion: For stabilized patients with community-onset EKP bacteremia after appropriate empirical antimicrobial therapy, cefazolin might be recommended as a definitive therapy for cefazolin-susceptible EKP bacteremia, based on the contemporary CLSI breakpoint.

Antagonistic activity of Bacillus subtilis strains isolated from various sources

2018 ◽  
Vol 8 (2) ◽  
pp. 354-364
Author(s):  
A. N. Irkitova ◽  
A. V. Grebenshchikova ◽  
A. V. Matsyura
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Wild Strain ◽  
Fish Farming ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
E Coli ◽  
Long Period ◽  
Test Culture ◽  
Agar Media

<p>An important link in solving the problem of healthy food is the intensification of the livestock, poultry and fish farming, which is possible only in the adoption and rigorous implementation of the concept of rational feeding of animals. In the implementation of this concept required is the application of probiotic preparations. Currently, there is an increased interest in spore probiotics. In many ways, this can be explained by the fact that they use no vegetative forms of the bacilli and their spores. This property provides spore probiotics a number of advantages: they are not whimsical, easily could be selected, cultivated, and dried. Moreover, they are resistant to various factors and could remain viable during a long period. One of the most famous spore microorganisms, which are widely used in agriculture, is <em>Bacillus subtilis</em>. Among the requirements imposed to probiotic microorganisms is mandatory – antagonistic activity to pathogenic and conditional-pathogenic microflora. The article presents the results of the analysis of antagonistic activity of collection strains of <em>B. subtilis</em>, and strains isolated from commercial preparations. We studied the antagonistic activity on agar and liquid nutrient medias to trigger different antagonism mechanisms of <em>B. subtilis</em>. On agar media, we applied three diffusion methods: perpendicular bands, agar blocks, agar wells. We also applied the method of co-incubating the test culture (<em>Escherichia coli</em>) and the antagonist (or its supernatant) in the nutrient broth. Our results demonstrated that all our explored strains of <em>B. subtilis</em> have antimicrobial activity against a wild strain of <em>E. coli</em>, but to varying degrees. We identified strains of <em>B. subtilis</em> with the highest antagonistic effect that can be recommended for inclusion in microbial preparations for agriculture.</p><p><em><br /></em><em></em></p>

Substituted 4-Formyl-2H-chromen-2-ones: Their Reaction with N-(2,3,4,6-Tetra-Oacetyl- β-D-galactopyranosyl)thiosemicarbazide, Antibacterial and Antifungal Activity of Their Thiosemicarbazone Products

2020 ◽  
Vol 24 (19) ◽  
pp. 2272-2282
Author(s):  
Vu Ngoc Toan ◽  
Nguyen Minh Tri ◽  
Nguyen Dinh Thanh
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Selenium Dioxide ◽  
Antibacterial And Antifungal Activity ◽  
E Coli ◽  
Antibacterial And Antifungal Activities ◽  
Alkyl Ethers ◽  
Antibacterial And Antifungal

Several 6- and 7-alkoxy-2-oxo-2H-chromene-4-carbaldehydes were prepared from corresponding alkyl ethers of 6- and 7-hydroxy-4-methyl-2-oxo-2H-chromen-2-ones by oxidation using selenium dioxide. 6- and 7-Alkoxy-4-methyl-2H-chromenes were obtained with yields of 57-85%. Corresponding 4-carbaldehyde derivatives were prepared with yields of 41-67%. Thiosemicarbazones of these aldehydes with D-galactose moiety were synthesized by reaction of these aldehydes with N-(2,3,4,6-tetra-O-acetyl-β-Dgalactopyranosyl) thiosemicarbazide with yields of 62-74%. These thiosemicarbazones were screened for their antibacterial and antifungal activities in vitro against bacteria, such as Staphylococcus aureus, Escherichia coli, and fungi, such as Aspergillus niger, Candida albicans. Several compounds exhibited strong inhibitory activity with MIC values of 0.78- 1.56 μM, including 8a (against S. aureus, E. coli, and C. albicans), 8d (against E. coli and A. niger), 9a (against S. aureus), and 9c (against S. aureus and C. albicans).

Procaryotic Expression of Single-Chain Variable-Fragment (scFv) Antibodies: Secretion in L-Form Cells of Proteus mirabilis Leads to Active Product and Overcomes the Limitations of Periplasmic Expression in Escherichia coli

1998 ◽  
Vol 64 (12) ◽  
pp. 4862-4869 ◽  
Author(s):  
Jörg F. Rippmann ◽  
Michaela Klein ◽  
Christian Hoischen ◽  
Bodo Brocks ◽  
Wolfgang J. Rettig ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Proteus Mirabilis ◽  
Binding Activity ◽  
Host Cells ◽  
Heterologous Proteins ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
E Coli ◽  
Active Product ◽  
Periplasmic Expression

ABSTRACT Recently it has been demonstrated that L-form cells ofProteus mirabilis (L VI), which lack a periplasmic compartment, can be efficiently used in the production and secretion of heterologous proteins. In search of novel expression systems for recombinant antibodies, we compared levels of single-chain variable-fragment (scFv) production in Escherichia coliJM109 and P. mirabilis L VI, which express four distinct scFvs of potential clinical interest that show differences in levels of expression and in their tendencies to form aggregates upon periplasmic expression. Production of all analyzed scFvs in E. coli was limited by the severe toxic effect of the heterologous product as indicated by inhibition of culture growth and the formation of insoluble aggregates in the periplasmic space, limiting the yield of active product. In contrast, the L-form cells exhibited nearly unlimited growth under the tested production conditions for all scFvs examined. Moreover, expression experiments with P. mirabilis L VI led to scFv concentrations in the range of 40 to 200 mg per liter of culture medium (corresponding to volume yields 33- to 160-fold higher than those with E. coli JM109), depending on the expressed antibody. In a translocation inhibition experiment the secretion of the scFv constructs was shown to be an active transport coupled to the signal cleavage. We suppose that this direct release of the newly synthesized product into a large volume of the growth medium favors folding into the native active structure. The limited aggregation of scFv observed in the P. mirabilis L VI supernatant (occurring in a first-order-kinetics manner) was found to be due to intrinsic features of the scFv and not related to the expression process of the host cells. The P. mirabilis L VI supernatant was found to be advantageous for scFv purification. A two-step chromatography procedure led to homogeneous scFv with high antigen binding activity as revealed from binding experiments with eukaryotic cells.

scholarly journals In vitro activity of antimicrobial peptide CDP-B11 alone and in combination with colistin against colistin-resistant and multidrug-resistant Escherichia coli

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaitlin S. Witherell ◽  
Jason Price ◽  
Ashok D. Bandaranayake ◽  
James Olson ◽  
Douglas R. Call
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptide ◽  
Membrane Integrity ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
E Coli ◽  
Minimal Media

AbstractMultidrug-resistant bacteria are a growing global concern, and with increasingly prevalent resistance to last line antibiotics such as colistin, it is imperative that alternative treatment options are identified. Herein we investigated the mechanism of action of a novel antimicrobial peptide (CDP-B11) and its effectiveness against multidrug-resistant bacteria including Escherichia coli #0346, which harbors multiple antibiotic-resistance genes, including mobilized colistin resistance gene (mcr-1). Bacterial membrane potential and membrane integrity assays, measured by flow cytometry, were used to test membrane disruption. Bacterial growth inhibition assays and time to kill assays measured the effectiveness of CDP-B11 alone and in combination with colistin against E. coli #0346 and other bacteria. Hemolysis assays were used to quantify the hemolytic effects of CDP-B11 alone and in combination with colistin. Findings show CDP-B11 disrupts the outer membrane of E. coli #0346. CDP-B11 with colistin inhibits the growth of E. coli #0346 at ≥ 10× lower colistin concentrations compared to colistin alone in Mueller–Hinton media and M9 media. Growth is significantly inhibited in other clinically relevant strains, such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In rich media and minimal media, the drug combination kills bacteria at a lower colistin concentration (1.25 μg/mL) compared to colistin alone (2.5 μg/mL). In minimal media, the combination is bactericidal with killing accelerated by up to 2 h compared to colistin alone. Importantly, no significant red blood hemolysis is evident for CDP-B11 alone or in combination with colistin. The characteristics of CDP-B11 presented here indicate that it can be used as a potential monotherapy or as combination therapy with colistin for the treatment of multidrug-resistant infections, including colistin-resistant infections.

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