Microchip system for monitoring microbial physiological behaviour under drug influences

2009 ◽  
Vol 223 (6) ◽  
pp. 777-786 ◽  
Author(s):  
S Arora ◽  
C S Lim ◽  
J Y Foo ◽  
M K Sakharkar ◽  
P Dixit ◽  
...  
Keyword(s):  
Laboratory Tests ◽  
Single Step ◽  
Adaptive Mutation ◽  
Cell Behaviour ◽  
Effective Screening ◽  
E Coli ◽  
Similar Work ◽  
Drug Concentrations ◽  
Microbiological Laboratory

Single-step real-time high-throughput monitoring of drug influences on bacterial cell behaviour has become important with growing interests in personalized therapy and medication. Conventional microchip assemblies to perform similar work do exist. However, most of these devices have complex set-ups incorporating micromixers, separators, pumps, or valves. These microcomponents can sometimes damage the entities being monitored because of the creation of unfavourable biological environments. This paper presents a microchip-based system that enables single-step mixing of two solutions in various ratios, without the need for additional microcomponents such as mixers and pumps, in order to screen effectively their combinatory effects on cell outcomes. In this work, in-vitro experiments were carried out using ampicillin at various concentrations to investigate their effects on Escherichia coli ( E. coli). Results showed that the microchip provided effective screening, which yielded useful results such as effective dosages, ineffective dosages, and other possible outcomes; for instance, in this case, the occurrence of adaptive mutation of the bacteria at certain drug concentrations. Comparative microbiological laboratory tests were carried out as standard for confirmation of the results.

scholarly journals Mutant Prevention Concentration Siprofloksasin Terhadap Escherichia coli Patogen dari Kloaka Broiler Secara In Vitro

2021 ◽  
Vol 39 (1) ◽  
pp. 20
Author(s):  
Maria Fatima Palupi ◽  
Eli Nugraha ◽  
Meutia Hayati ◽  
Neneng Atikah
Keyword(s):  
Escherichia Coli ◽  
Bacterial Infections ◽  
Single Step ◽  
In Vitro Test ◽  
Mutant Selection ◽  
E Coli ◽  
Wide Range ◽  
Mutant Prevention Concentration ◽  
Production Animals

Mutant prevention concentration (MPC) is an in vitro test used to determine the lowest drug concentration needed to inhibit the growth of a single-step-mutant bacterial subpopulation. The purpose of this study was to determine the MPC value of ciprofloxacin against pathogenic Escherichia coli to obtained the range of mutant selection windows (MSW) of ciprofloxacin. Ciprofloxacin is a quinolone group that is included in the Highest Priority Critically Important Antimicrobials for Human Medicine but is also used for the treatment of bacterial infections in production animals. Twenty-four of pathogenic E. coli isolates sensitive to ciprofloxacin were tested to obtain MPC values and minimum inhibitory concentration (MIC) values. Test the MPC and MIC values to get the MSW range is done by the method of agar dilution. Mueller-Hinton agar containing standard ciprofloxacin was inoculated with 1010 cfu E. coli for the MPC test and 104 for the MIC test. Based on the MPC test results, the MPC value of ciprofloxacin was 4-64 μg / mL (22.96 ± 19.07 μg / mL) and there was one isolate which had an MPC> 256 μg / mL. These results give a wide range of MSW with a lower limit of the MIC value of 0.25 - 2 µg / mL (0.55 ± 0.37 µg / mL) to the upper limit of the MPC value of 4-64 µg / mL (22.96 ± 19.07 μg / mL). Based on the results of this MPC assessment it can be concluded that the dose of ciprofloxacin in production animals has a wide range of MSW that is allow for single-step mutants.

scholarly journals Antibiotic resistance in Escherichia coli causing generalized infections in chickens in the UK in 1982: the relationship between the results of in vitro and in vivo furazolidone sensitivity tests

1984 ◽  
Vol 93 (3) ◽  
pp. 445-453 ◽  
Author(s):  
H. Williams Smith ◽  
M. A. Lovell
Keyword(s):  
Escherichia Coli ◽  
Laboratory Tests ◽  
Tetracycline Resistance ◽  
E Coli ◽  
Sensitivity Tests ◽  
Similar Survey ◽  
The Uk ◽  
The Relationship

SummaryCompared with a similar survey conducted ten years previously, a survey conducted in 1982, eleven years after the implementation of legislation forbidding the routine use of feeds containing ‘therapeutic’ antibiotics, revealed a decreased incidence of resistance to tetracyclines, furazolidone and sulphonamides in Escherichia coli strains causing generalized infections in chickens in the UK; the decrease was particularly marked in the case of tetracycline resistance, 17·9% of strains in 1982 being resistant to this antibiotic compared with 31·2% in 1972.Giving furazolidone to groups of chickens inoculated intramuscularly with O2:K1 strains of E. coli of differing degrees of furazolidone sensitivity indicated that great care is required in the performance and interpretation of laboratory tests for sensitivity to this antibiotic. Infections caused by strains that required as little as 1·25 μg/ml of furazolidone to inhibit their multiplication in laboratory tests responded poorly to furazolidone treatment; those that were inhibited by less responded well, better than to treatment with tetrac3rcline, chloramphenicol. ampicillin or trimethoprim.

scholarly journals Comparative Mutant Prevention Concentrations of Pradofloxacin and Other Veterinary Fluoroquinolones Indicate Differing Potentials in Preventing Selection of Resistance

2005 ◽  
Vol 49 (10) ◽  
pp. 4166-4173 ◽  
Author(s):  
H.-G. Wetzstein
Keyword(s):  
Bacterial Infections ◽  
Bacterial Populations ◽  
E Coli ◽  
Staphylococcus Intermedius ◽  
Drug Concentrations ◽  
Animal Medicine ◽  
Species Being ◽  
Selection Of ◽  
Selection Of Resistance

ABSTRACT Pradofloxacin (PRA) is an 8-cyano-fluoroquinolone (FQ) being developed to treat bacterial infections in dogs and cats. Its mutant prevention concentrations (MPC) were determined for Escherichia coli ATCC 8739 at 0.225 μg/ml, and for Staphylococcus aureus ATCC 6538 at 0.55 μg/ml. At drug concentrations equal to or above the MPC, growth (implying selective clonal expansion) of first-step FQ-resistant variants, naturally present in large bacterial populations, was inhibited. MPC90 derived from 10 clinical isolates each of E. coli and Staphylococcus intermedius, the latter species being of greater clinical relevance than S. aureus in companion-animal medicine, amounted to 0.2 to 0.225 and 0.30 to 0.35 μg/ml, respectively. MPCs of other veterinary FQs were assessed to determine relative in vitro potencies. The MPCs of marbofloxacin, enrofloxacin, danofloxacin, sarafloxacin, orbifloxacin, and difloxacin were 1.2-, 1.4-, 2.3-, 2.4-, 5-, and 7-fold higher than the MPC of PRA for E. coli ATCC 8739, and 6-, 6-, 19-, 15-, 15-, and 31-fold higher than the MPC of PRA for S. aureus ATCC 6538, respectively. MPC curves revealed a pronounced heterogeneity in susceptibility within populations of ≥4 × 109 CFU employed, extending to 10-fold above the MICs. The duration of incubation and, for S. aureus, inoculum density profoundly affected the MPCs. With appropriate dosing, PRA may combine high therapeutic efficacy with a high potential for restricting the selection for FQ resistance under field conditions in the species analyzed.

scholarly journals Direct purification of CRISPR/Cas ribonucleoprotein from E. coli in a single step

2018 ◽  
Author(s):  
Siyu Lin ◽  
Jie Qiao ◽  
Lixin Ma ◽  
Yi Liu
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Cost Effective ◽  
Nuclease Activity ◽  
Single Step ◽  
Simple Method ◽  
E Coli ◽  
Purification System

AbstractCRISPR/Cas ribonucleoprotein (RNP) complexes have been recently used as promising biological tools with plenty of applications, however, there are by far no efficient methods to prepare them at large scale and low cost. Here, we present a simple method to directly produce and purify Cas RNP, including the widely used Cas9 and Cas12a nuclease, from E.coli in a single step using an ultra-high-affinity CL7/Im7 purification system. The prepared Cas RNP shows high stability, solid nuclease activity in vitro, and profound genome editing efficiency in vivo. Our method is convenient, cost-effective, and applicable to prepare other CRISPR associated nucleases.

scholarly journals Cefoxitin as an Alternative to Carbapenems in a Murine Model of Urinary Tract Infection Due to Escherichia coli Harboring CTX-M-15-Type Extended-Spectrum β-Lactamase

2012 ◽  
Vol 56 (3) ◽  
pp. 1376-1381 ◽  
Author(s):  
Raphaël Lepeule ◽  
Etienne Ruppé ◽  
Patrick Le ◽  
Laurent Massias ◽  
Françoise Chau ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Murine Model ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
Drug Concentrations ◽  
Tract Infections

ABSTRACTWe investigated the efficiency of the cephamycin cefoxitin as an alternative to carbapenems for the treatment of urinary tract infections (UTIs) due toEscherichia coliproducing CTX-M-type extended-spectrum β-lactamases. The susceptible, UTI-inducingE. coliCFT073-RR strain and its transconjugant CFT073-RR Tc (pblaCTX-M-15), harboring ablaCTX-M-15carrying-plasmid, were used for all experiments. MICs of cefoxitin (FOX), ceftriaxone (CRO), imipenem (IMP), and ertapenem (ETP) for CFT073-RR and CFT073-RR Tc (pblaCTX-M-15) were 4 and 4, 0.125 and 512, 0.5 and 0.5, and 0.016 and 0.032 μg/ml, respectively. Bactericidal activity was similarly achievedin vitroagainst the two strains after 3 h of exposure to concentrations of FOX, IMI, and ETP that were 2 times the MIC, whereas CRO was not bactericidal against CFT073-RR Tc (pblaCTX-M-15). The frequencies of spontaneous mutants of the 2 strains were not higher for FOX than for IMP or ETP. In the murine model of UTIs, mice infected for 5 days were treated over 24 h. Therapeutic regimens in mice (200 mg/kg of body weight every 3 h or 4 h for FOX, 70 mg/kg every 6 h for CRO, 100 mg/kg every 2 h for IMP, and 100 mg/kg every 4 h for ETP) were chosen in order to reproduce the percentage of time that free-drug concentrations above the MIC are obtained in humans with standard regimens. All antibiotic regimens produced a significant reduction in bacterial counts (greater than 2 log10CFU) in kidneys and bladders for both strains (P< 0.001) without selecting resistant mutantsin vivo, but the reduction obtained with CRO against CFT073-RR Tc (pblaCTX-M-15) in kidneys was significantly lower than that obtained with FOX. In conclusion, FOX appears to be an effective therapeutic alternative to carbapenems for the treatment of UTIs due to CTX-M-producingE. coli.

Purification of Urokinase from Complex Mixtures Using Immobilized Monoclonal Antibody Against Urokinase Light Chain

1983 ◽  
Vol 49 (01) ◽  
pp. 024-027 ◽  
Author(s):  
David Vetterlein ◽  
Gary J Calton
Keyword(s):  
Monoclonal Antibody ◽  
Light Chain ◽  
Culture Media ◽  
Biological Fluids ◽  
Single Step ◽  
High Yield ◽  
Step Method ◽  
Commercial Preparation ◽  
E Coli ◽  
Tissue Culture Media

SummaryThe preparation of a monoclonal antibody (MAB) against high molecular weight (HMW) urokinase light chain (20,000 Mr) is described. This MAB was immobilized and the resulting immunosorbent was used to isolate urokinase starting with an impure commercial preparation, fresh urine, spent tissue culture media, or E. coli broth without preliminary dialysis or concentration steps. Monospecific antibodies appear to provide a rapid single step method of purifying urokinase, in high yield, from a variety of biological fluids.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

Антимикробная активность лиофилизированного водного извлечения Caragana jubata (Pall.) Poir.

2020 ◽  
Vol 54 (3) ◽  
pp. 42-44
Author(s):  
Павел Алексеевич Какорин ◽  
Татьяна Владимировна Фатеева ◽  
Ольга Ивановна Терешкина ◽  
Ирина Борисовна Перова ◽  
Галина Владиславовна Раменская ◽  
...  
Keyword(s):  
E Coli

На основании ранее проведенных исследований установлен профиль флавоноидов лиофилизированного водного извлечения, полученного из побегов C. jubata. В связи с тем, что, согласно данным литературы, флавоноиды являются потенциальными ингибиторами микроорганизмов, проведено изучение антимикробной активности лиофилизата в опытах in vitro с использованием скринигового метода определения антимикробной активности для препаратов растительного происхождения. При изучении бактериостатической и фунгистатической активности в опытах in vitro использовали метод двукратного серийного разведения препаратов в жидких питательных средах. В результате исследования лиофилизированного водного извлечения караганы гривастой установлено наличие умеренной антимикробной активности в отношении всех изученных штаммов патогенных микроорганизмов: грамположительных и грамотрицательных бактерий (S. aureus, E. coli, P. vulgaris, P. aeruginosa), дрожжеподобных и мицелиальных грибов (C. albicans, M. canis). Полученные данные позволяют рекомендовать лиофилизированное водное извлечение караганы гривастой для создания на его основе лекарственных форм наружного применения для лечения заболеваний кожи и слизистых оболочек, связанных с бактериальным воспалительным процессом.

Влияние in vitro изолированного и сочетанного с антибактериальными средствами применения бовгиалуронидазы азоксимер на целостность бактериальной биопленки и жизнеспосоность микроорганизмов

2020 ◽  
Vol 83 (2) ◽  
pp. 38-44
Author(s):  
Е. Ю. Тризна ◽  
Д. Р. Байдамшина ◽  
Александр А. Виницкий ◽  
А. Р. Каюмов
Keyword(s):  
E Coli

Исследована способность лиофилизата бовгиалуронидазы азоксимера («Лонгидаза») разрушать бактериальные биопленки S. aureus, E. faecalis, E. coli, а также сочетанное действие препарата с антибактериальными средствами. Показано, что 2 ч инкубации бовгиалуронидазы азоксимер в концентрации 750 – 1500 МЕ/мл вызывает двукратное снижение биомассы матрикса зрелых биопленок E. faecalis и E. coli, и на 60 % — S. aureus. Данный ферментный препарат не влияет на образование бактериальных биопленок. При сочетанном применении с антибактериальными средствами препарат повышает их эффективность в отношении бактерий в составе биопленок. Так, концентрация ципро-флоксацина и амоксициллина, необходимая для снижения количества КОЕ на 3 порядка в биопленке E. faecalis, в присутствии бовгиалуронидазы азоксимера снижается в 16 раз (p < 0,05). В присутствии фермента в 16 раз меньшие концентрации цефуроксима, фосфомицина, ципрофлоксацина и амикацина достаточны для снижения количества КОЕ на 3 порядка в биопленке E. coli (p < 0,05), и в значительно меньшей концентрации цефуроксим оказывает бактерицидное действие на клетки в биопленке S. aureus (p < 0,05). Вероятно, бовгиалуронидаза азоксимер увеличивает проникновение антибактериальных средств к клеткам бактерий в биопленке, что обеспечивает потенцирование их антибактериального эффекта. Такое действие ферментного препарата позволяет снизить дозу и повысить безопасность антибактериальных средств при сохранении их эффективности.

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