scholarly journals Inoculum size effects in blaIMP-6 and plasmid-mediated quinolone resistance gene-positive Enterobacteriaceae in Japan

2019 ◽  
Author(s):  
Yoshihiko Ogawa ◽  
Ryuichi Nakano ◽  
Kei Kasahara ◽  
Tomoki Mizuno ◽  
Nobuyasu Hirai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Klebsiella Pneumoniae ◽  
Size Effect ◽  
Resistance Gene ◽  
Size Effects ◽  
Antimicrobial Agents ◽  
Inoculum Size ◽  
Experimental Strains

AbstractThe aim of this study was to examine the resistance genes in clinical isolates which produced IMP-6 type metallo-β-lactamase lactamase (MBL) and had mildly reduced susceptibilities to levofloxacin and/or amikacin. The inoculum size effect was also assessed. A total of 14 Enterobacteriaceae isolates (2 Escherichia coli and 12 Klebsiella pneumoniae) which produced IMP-6 MBL, and had mild increases in their MICs for levofloxacin and amikacin were examined. Thirteen out of 14 isolates harbored CTX-M-2, with the remaining isolate co-harboring CTX-M-2 and CTX-M-1 as ESBLs. All isolates carried one or more PMQRs; aac(6′)-Ib-cr was the most prevalent (92.8%), followed by oqxA (64.3%), qnrS (42.9%), oqxAB (21.4%), and qnrB (14.3%). The inoculum size effects were significant in all strains for meropenem, 13 for imipenem, 7 for levofloxacin, and 3 for amikacin. Conjugation was successfully performed with 8 isolates and 11 strains were obtained. Eleven of the experimental strains (100%), and 8 strains (72.7%) showed inoculum size effects for meropenem and imipenem, respectively. No inoculum size effect was seen for levofloxacin. Four strains harbored qnr genes and 2 strains harbored qnr genes and QRDR mutations concurrently. blaIMP-6 positive Enterobacteriaceae with mildly reduced susceptibilities to levofloxacin and/or amikacin also harbored at least one plasmid-mediated drug resistance gene. These represent an unrecognized threat, capable of compromising the in vitro activity of many classes of antimicrobial agents. We conclude that IMP-6 MBL plays an important role in decreasing the MIC for carbapenems, whereas qnr does not for levofloxacin.

scholarly journals In vitro activity of three different antimicrobial agents against ESBL producing Escherichia coli and Klebsiella pneumoniae blood isolates

2005 ◽  
Vol 160 (2) ◽  
pp. 135-140 ◽  
Author(s):  
Ahmet Kizirgil ◽  
Kutbettin Demirdag ◽  
Mehmet Ozden ◽  
Yasemin Bulut ◽  
Yusuf Yakupogullari ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Agents ◽  
Vitro Activity ◽  
In Vitro Activity

scholarly journals Antimicrobial agents active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae isolates in Lebanon

2018 ◽  
Vol 12 (03) ◽  
pp. 164-170 ◽  
Author(s):  
George Farah Araj ◽  
Aline Z Avedissian ◽  
Lina Y Itani ◽  
Jowana A Obeid
Keyword(s):  
Escherichia Coli ◽  
Retrospective Study ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Agents ◽  
Medical Center ◽  
In Vitro Activity ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Promising Treatment

Introduction: It is not yet clear which antimicrobial agents should be used to treat the ominously increasing infections with carbapenem-resistant (CR) bacteria. We therefore investigated the activity of different antimicrobial agents against CR Escherichia coli and Klebsiella pneumoniae in Lebanon. Methodology: This retrospective study assessed the minimum inhibitory concentrations (MICs) of three carbapenems (by Etest), as well as the in vitro activity of eight other antimicrobials (by disk diffusion) against CR E. coli (n = 300) and K. pneumoniae (n = 232) isolates recovered at a major University Medical Center in Lebanon. Results: Higher percentages of isolates showing carbapenem MICs of ≤ 8 µg/mL were noted among the CR E. coli compared to the CR K. pneumoniae for ertapenem (48% vs 27%), imipenem (74 % vs 58%) and meropenem (82% vs 63%). Among the eight other antimicrobials, activity was generally higher when the MICs for the three carbapenems were ≤ 8 µg/mL. Regardless of the MIC level of the three carbapenems, very low susceptibility rates (≤ 33%) were noted for ciprofloxacin, trimethoprim-sulfamethoxazole and aztreonam against both E. coli and K. pneumoniae isolates. With Amikacin, higher susceptibility rates were seen against E. coli isolates (81%-97%) than against K. pneumoniae isolates (55%-86%), also reflecting higher activity than gentamicin (44%-54%). The best activity (66%-100%) was observed for tigecycline, colistin and fosfomycin against both CR species. Conclusions: Based on the in vitro findings in this study, the combination of a carbapenem showing an MIC of ≤ 8 µg/mL together with an active colistin, tigecycline, or fosfomycin, would offer a promising treatment option for patients infected with CR E. coli or K. pneumoniae.

scholarly journals PREVALENCE OF BLATEM, BLASHV, AND BLACTX-M GENES AMONG ESBL-PRODUCING KLEBSIELLA PNEUMONIAE AND ESCHERICHIA COLI ISOLATED FROM THALASSEMIA IN ERBIL, IRAQ

2019 ◽  
Vol 11 (1) ◽  
pp. e2019041 ◽  
Author(s):  
Pishtiwan Ahmad Hamad ◽  
Khalil Mustafa Khadija
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistance Pattern ◽  
Molecular Characteristics ◽  
E Coli ◽  
Multiplex Pcr Assay ◽  
To Come

Due to the recent appearance of organisms that are resistant to several drugs (multidrug-resistant) like Enterobacteriaceae that produce extended-spectrum β-lactamase (ESBL, concerns have remarkably increased regarding the suitable treatment of infections. The present study was an investigation into ESBL molecular characteristics among clinical isolates of Klebsiella pneumoniae and Escherichia coli resulting in UTIs and their pattern of antimicrobial resistance in order to come up with helpful information on the epidemiology of these infections and risk factors accompanied with them. In order to conduct the study, 20 K. pneumoniae and 48 E. coli were isolated and retrieved from thalassemia center in Erbil, Iraq during July 2016 and September 2016. The collected strains were analyzed and the profile of their antimicrobial susceptibility was specified. In order to spot β-lactamase genes (i.e. blaTEM, blaSHV, and blaCTX-M), polymerase chain reaction was conducted. The results obtained from multiplex PCR assay showed that out of the collected strains of ESBL-producing E. coli, 37 had 81% blaTEM, 16.2% blaSHV, and 32.4% blaCTX-M genes. Similarly, 64.7% blaTEM, 35.2% blaSHV, and 41.1% blaCTX-M genes existed in the isolates of K. pneumoniae. It was found that antibiotic resistance pattern of E. coli and K. pneumoniae isolates to 20 antibiotics varied widely. It was also concluded that the majority of the K. pneumoniae and E. coli isolates were multi-drug resistant (MDR). Moreover, 75% and 87.5% of respectively K. pneumoniae and E. coli isolates showed the MDR phenotypes. TEM prevalence was high among other types of ESBLs. Over all, the most active antimicrobial agents in vitro remained to be the carbapenems.

Activité antibactérienne de l’huile essentielle de Pelargonium x asperum et son potentiel synergique avec la nisine

2019 ◽  
Vol 17 (3) ◽  
pp. 140-148 ◽  
Author(s):  
A. Ouelhadj ◽  
L. Ait Salem ◽  
D. Djenane
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Nous Avons ◽  
Activité Antibactérienne

Ce travail vise l’étude de l’activité antibactérienne de l’huile essentielle (HE) de Pelargoniumx asperum et de la bactériocine, la nisine seul et en combinaison vis-à-vis de six bactéries dont quatre sont multirésistantes d’origine clinique. L’activité antibactérienne in vitro a été évaluée par la méthode de diffusion sur gélose. La concentration minimale inhibitrice (CMI) est aussi déterminée pour HE. Les résultats ont révélé une activité antibactérienne significative exercée par HE visà-vis de Staphylococcus aureus (ATCC 43300), Staphylococcus aureus et Escherichia coli avec des diamètres d’inhibition de 36,00 ; 22,50 et 40,00 mm, respectivement. Cependant, l’HE de Pelargonium asperum a montré une activité antibactérienne supérieure par rapport à la nisine. Les valeurs des CMI rapportées dans cette étude sont comprises entre 1,98–3,96 μl/ml. Les combinaisons réalisées entre HE et la nisine ont montré un effet additif vis-à-vis de Escherichia coli (ATCC 25922) avec (50 % HE Pelargonium asperum + 50 % nisine). Par contre, nous avons enregistré une synergie vis-à-vis de Klebsiella pneumoniae avec (75 % HE Pelargonium asperum + 25 % nisine) et contre Pseudomonas aeruginosa avec les trois combinaisons testées. Les résultats obtenus permettent de dire que l’HE de Pelargonium asperum possède une activité antibactérienne ainsi que sa combinaison avec la nisine pourrait représenter une bonne alternative pour la lutte contre l’antibiorésistance.

scholarly journals Bactericidal Activities of Meropenem and Ertapenem against Extended-Spectrum-β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in a Neutropenic Mouse Thigh Model

2007 ◽  
Vol 51 (4) ◽  
pp. 1481-1486 ◽  
Author(s):  
C. Andrew DeRyke ◽  
Mary Anne Banevicius ◽  
Hong Wei Fan ◽  
David P. Nicolau
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Infection Model ◽  
Bacterial Reduction ◽  
Efficacy Analysis ◽  
Percent Time ◽  
Extended Spectrum ◽  
Wide Range

ABSTRACT The purpose of this study was to examine the in vivo efficacies of meropenem and ertapenem against extended-spectrum-β-lactamase (ESBL)-producing isolates with a wide range of MICs. Human-simulated dosing regimens in mice were designed to approximate the free drug percent time above the MIC (fT>MIC) observed for humans following meropenem at 1 g every 8 h and ertapenem at 1 g every 24 h. An in vivo neutropenic mouse thigh infection model was used to examine the bactericidal effects against 31 clinical ESBL Escherichia coli and Klebsiella pneumoniae isolates and 2 non-ESBL isolates included for comparison at a standard 105 inoculum. Three isolates were examined at a high 107 inoculum as well. Meropenem displayed greater in vitro potency, with a median MIC (range) (μg/ml) of 0.125 (0.03 to 32), than did ertapenem, with 0.5 (0.012 to 128). Seven of the 31 ESBL isolates were removed from the efficacy analysis due to their inability to establish infection in the mouse model. When MICs were ≤1.5 μg/ml for ertapenem (≤0.5 μg/ml for meropenem), similar reductions in CFU (≈ 2-log kill) were observed for both ertapenem (fT>MIC ≥ 23%) and meropenem (fT>MIC ≥ 75%). Ertapenem showed bacterial regrowth for seven of eight isolates, with MICs of ≥2 μg/ml (fT>MIC ≤ 20%), while meropenem displayed antibacterial potency that varied from a static effect to a 1-log bacterial reduction in these isolates (fT>MIC = 30 to 65%). At a 107 inoculum, both agents eradicated bacteria due to adequate exposures (fT>MIC = 20 to 45%). Due to low MICs, no difference in bacterial kill was noted for the majority of ESBL isolates tested. However, for isolates with raised ertapenem MICs of ≥2 μg/ml, meropenem displayed sustained efficacy due to its greater in vitro potency and higher resultant fT>MIC.

scholarly journals Comparison of the effects of aztreonam and tigemonam against Escherichia coli and Klebsiella pneumoniae in vitro and in vivo.

1991 ◽  
Vol 35 (3) ◽  
pp. 417-422 ◽  
Author(s):  
M L van Ogtrop ◽  
H Mattie ◽  
H F Guiot ◽  
E van Strijen ◽  
B R Sekh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae

scholarly journals Efeito antimicrobiano do extrato de Cranberry sobre micro-organismos causadores de infecção urinária

2016 ◽  
Vol 11 (31) ◽  
pp. 113-122
Author(s):  
Carla Franco Porto Belmont Souza ◽  
Luiz Eduardo Souza da Silva Irineu ◽  
Renan Silva De Souza ◽  
Renato da Silva Teixeira ◽  
Ivina Sanches Pereira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Proteus Mirabilis ◽  
Enterococcus Faecium ◽  
Vaccinium Macrocarpon ◽  
Mueller Hinton

A resistência microbiana tem se mostrado um problema de proporções mundiais, causando estado de morbidade e mortalidade em diversos pacientes. Em vista disso, tem crescido a busca por métodos alternativos naturais de profilaxia. A investigação clínica sugere que o Extrato de Cranberry está entre as melhores propostas de prevenção natural. O Cranberry (Vaccinium macrocarpon) é um fruto que tem crescido comercialmente pelo sabor e propriedades benéficas à saúde. Dentre as formas comercializadas estão: o suco, o chá e as cápsulas contendo o extrato seco. A ação desta planta está relacionada ao tratamento de doenças do trato urinário, por possuir substâncias que inibem a adesão bacteriana ao epitélio do trato urinário, dificultando sua proliferação e reprodução. Dentre todas as infecções relacionadas à assistência a saúde, a Infecção do Trato Urinário é a mais frequentemente associada a procedimentos invasivos. Se não for tratada, pode resultar em complicações como pielonefrite aguda, bacteremia e pionefrose. Portanto, cranberry pode ser uma nova alternativa para o combate das infecções uroepiteliais, por ser um produto natural de preço acessível, e com formas de comercialização diversificada, ao contrário dos antimicrobianos convencionais, que por sua vez são caros e podem acabar causando resistência nos micro-organismos. Este trabalho teve como objetivo avaliar in vitro a atividade antimicrobiana do extrato de Cranberry, adquirido em farmácia de manipulação, sobre 8 micro-organismos isolados de infecções urinárias. As cepas utilizadas, adquiridas da coleção da FIOCRUZ, foram: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Serratia marscecens, Staphylococcus aureus, Enterococcus faecalis e Enterococcus faecium. No estudo, foram utilizados o caldo Mueller Hinton (MH), Extrato de Cranberry e as bactérias patogênicas. O ensaio foi realizado em triplicata, com o uso de um controle de crescimento dos micro-organismos e o experimento para avaliação do crescimento bacteriano na presença do extrato. A turbidez foi medida com o auxílio de um espectrofotômetro, no comprimento de onda de 600 nm, antes e após 24 horas de incubação à 37 ºC. O procedimento forneceu a Densidade Ótica, do qual possibilitou a identificação da inibição microbiana. Para análise estatística foi utilizado o Teste t de Student. O Extrato de Cranberry apresentou atividade antimicrobiana sobre as bactérias Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Serratia marscecens e Enterococcus faecalis (p < 0,05), confirmando seu efeito benéfico em infecções urinárias. No entanto, não teve efeito inibitório significativo sobre Pseudomonas aeruginosa, Proteus mirabilis e Enterococcus faecium (p > 0,05).

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