scholarly journals Uji Daya Hambat Ekstrak Daun Sawo terhadap Bakteri Escherichia coli secara In Vitro

2017 ◽  
Vol 6 (2) ◽  
pp. 289
Author(s):  
Nastasha Mufti ◽  
Elizabeth Bahar ◽  
Dessy Arisanti
Keyword(s):  
Escherichia Coli ◽  
Coli Strain ◽  
Manilkara Zapota ◽  
E Coli

Daun sawo merupakan bagian dari tanaman sawo (Manilkara zapota) yang sering digunakan masyarakat sebagai obat antidiare. Daun sawo mengandung senyawa saponin, tanin, dan flavonoid yang dapat bersifat sebagai antibakteri sehingga diduga mampu menghambat pertumbuhan bakteri penyebab diare. Tujuan penelitian ini adalah menentukan daya hambat ekstrak daun sawo terhadap bakteri Escherichia coli (E. coli) strain patogen secara in-vitro. Jenis penelitian adalah eksperimental laboratorium menggunakan 6 bakteri uji E. coli berbeda dengan 2 kali pengulangan menggunakan metode difusi. Penelitian dilakukan di Laboratorium Kimia Organik FMIPA dan Laboratorium Mikrobiologi FK UNAND pada bulan Agustus 2016 sampai April 2017. Sampel yang digunakan adalah daun sawo yang telah dilakukan proses ekstraksi maserasi menggunakan etanol. Hasil penelitian menunjukkan ekstrak daun sawo dengan konsentrasi 15%, 30%, 45%, 60%, dan 100% memiliki daya hambat yang berbeda-beda terhadap bakteri uji E. coli. Konsentrasi ekstrak daun sawo yang paling efektif yaitu konsentrasi 100%. Dari penelitian ini disimpulkan bahwa ekstrak daun sawo mempunyai sifat antibakteri terhadap bakteri uji Escherichia coli strain patogen.

scholarly journals Uji Daya Hambat Ekstrak Daun Sawo terhadap Bakteri Escherichia coli secara In Vitro

2017 ◽  
Vol 6 (2) ◽  
pp. 289
Author(s):  
Nastasha Mufti ◽  
Elizabeth Bahar ◽  
Dessy Arisanti
Keyword(s):  
Escherichia Coli ◽  
Coli Strain ◽  
Manilkara Zapota ◽  
E Coli

Daun sawo merupakan bagian dari tanaman sawo (Manilkara zapota) yang sering digunakan masyarakat sebagai obat antidiare. Daun sawo mengandung senyawa saponin, tanin, dan flavonoid yang dapat bersifat sebagai antibakteri sehingga diduga mampu menghambat pertumbuhan bakteri penyebab diare. Tujuan penelitian ini adalah menentukan daya hambat ekstrak daun sawo terhadap bakteri Escherichia coli (E. coli) strain patogen secara in-vitro. Jenis penelitian adalah eksperimental laboratorium menggunakan 6 bakteri uji E. coli berbeda dengan 2 kali pengulangan menggunakan metode difusi. Penelitian dilakukan di Laboratorium Kimia Organik FMIPA dan Laboratorium Mikrobiologi FK UNAND pada bulan Agustus 2016 sampai April 2017. Sampel yang digunakan adalah daun sawo yang telah dilakukan proses ekstraksi maserasi menggunakan etanol. Hasil penelitian menunjukkan ekstrak daun sawo dengan konsentrasi 15%, 30%, 45%, 60%, dan 100% memiliki daya hambat yang berbeda-beda terhadap bakteri uji E. coli. Konsentrasi ekstrak daun sawo yang paling efektif yaitu konsentrasi 100%. Dari penelitian ini disimpulkan bahwa ekstrak daun sawo mempunyai sifat antibakteri terhadap bakteri uji Escherichia coli strain patogen.

scholarly journals Novel Plasmid-Mediated 16S rRNA m1A1408 Methyltransferase, NpmA, Found in a Clinically Isolated Escherichia coli Strain Resistant to Structurally Diverse Aminoglycosides

2007 ◽  
Vol 51 (12) ◽  
pp. 4401-4409 ◽  
Author(s):  
Jun-ichi Wachino ◽  
Keigo Shibayama ◽  
Hiroshi Kurokawa ◽  
Kouji Kimura ◽  
Kunikazu Yamane ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
16S Rrna ◽  
Recombinant Plasmid ◽  
Coli Strain ◽  
Methyltransferase Activity ◽  
Ribosomal Subunits ◽  
E Coli ◽  
Rrna Molecule ◽  
A Site

ABSTRACT We have isolated a multiple-aminoglycoside-resistant Escherichia coli strain, strain ARS3, and have been the first to identify a novel plasmid-mediated 16S rRNA methyltransferase, NpmA. This new enzyme shared a relatively low level of identity (30%) to the chromosomally encoded 16S rRNA methyltransferase (KamA) of Streptomyces tenjimariensis, an actinomycete aminoglycoside producer. The introduction of a recombinant plasmid carrying npmA could confer on E. coli consistent resistance to both 4,6-disubstituted 2-deoxystreptamines, such as amikacin and gentamicin, and 4,5-disubstituted 2-deoxystreptamines, including neomycin and ribostamycin. The histidine-tagged NpmA elucidated methyltransferase activity against 30S ribosomal subunits but not against 50S subunits and the naked 16S rRNA molecule in vitro. We further confirmed that NpmA is an adenine N-1 methyltransferase specific for the A1408 position at the A site of 16S rRNA. Drug footprinting data indicated that binding of aminoglycosides to the target site was apparently interrupted by methylation at the A1408 position. These observations demonstrate that NpmA is a novel plasmid-mediated 16S rRNA methyltransferase that provides a panaminoglycoside-resistant nature through interference with the binding of aminoglycosides toward the A site of 16S rRNA through N-1 methylation at position A1408.

scholarly journals 611. Fosfomycin Resistance of Multidrug-Resistant Escherichia coli and Mechanisms of Fosfomycin Resistance

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S285-S285
Author(s):  
Hyeri Seok ◽  
Ji Hoon Jeon ◽  
Hee Kyoung Choi ◽  
Won Suk Choi ◽  
Dae Won Park ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Coli Strain ◽  
Resistant Bacteria ◽  
E Coli ◽  
Broth Microdilution Method ◽  
Fosfomycin Resistance

Abstract Background Fosfomycin is one of the antibiotics that may be a candidate for the next-generation antimicrobial agents againt multidrug-resistant bacteria. To date, it is known that the resistance rate is not high for Escherichia coli. However, it is necessary to update the fosfomycin resistance rates in E. coli according to the studies that extended spectrum β-lactamase (ESBL) producing E. coli strains are highly resistance to fosfomycin. We evaluated the resistance rate of fosfomycin, the resistant mechanism of fosfomycin in E. coli, and the activity of fosfomycin against susceptible and resistant strains of E. coli. Methods A total of 283 clinical isolates was collected from patients with Escherichia coli species during the period of January 2018 to June 2018, in three tertiary hospitals of Republic of Korea. In vitro antimicrobial susceptibility tests were performed in all E. coli isolates using the broth microdilution method according to the Clinical and Laboratory Standard Institute (CLSI). Multilocus sequence typing (MLST) of the Oxford scheme was conducted to determine the genotypes of E. coli isolated. Fosfomycin genes were investigated for all fosfomycin-resistant E. coli strains. Results The overall resistance rate to fosfomycin was 10.2%, compared with 53.4%, 46.3%, 41.3%, 31.1%, 10.6%, 2.5%, and 2.1% for ciprofloxacin, cefixime, cefepime, piperacillin/tazobactam, colistin, ertapenem, and amikacin, respectively. The 29 fosfomycin-resistant isolates did not show a clonal pattern on the phylogenetic tree. MurA and glp genes were identified in all strains. FosA3 were identified in two strains and uhp gene were identified in 4 strains. In time-kill curve studies, fosfomycin was more bactericidal than cefixime against all sensitive E. coli strain. Morever, fosfomycin was more bactericidal than piperacillin/tazobactam against ESBL-producing E. coli strain. Conclusion The resistant rate of fosfomycin to E. coli is still low. Fosfomycin was active against E. coli including ESBL producing strains. Disclosures All authors: No reported disclosures.

scholarly journals Virulence Potential of a Multidrug-Resistant Escherichia coli Strain Belonging to the Emerging Clonal Group ST101-B1 Isolated from Bloodstream Infection

2020 ◽  
Vol 8 (6) ◽  
pp. 827 ◽  
Author(s):  
Ana Carolina M. Santos ◽  
Rosa M. Silva ◽  
Tiago B. Valiatti ◽  
Fernanda F. Santos ◽  
José F. Santos-Neto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Bloodstream Infection ◽  
Galleria Mellonella ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
Pathogenic Potential ◽  
E Coli ◽  
Antimicrobial Resistance Genes

Escherichia coli EC121 is a multidrug-resistant (MDR) strain isolated from a bloodstream infection of an inpatient with persistent gastroenteritis and T-zone lymphoma that died due to septic shock. Despite causing an extraintestinal infection, previous studies showed that it did not have the usual characteristics of an extraintestinal pathogenic E. coli. Instead, it belonged to phylogenetic group B1 and harbored few known virulence genes. To evaluate the pathogenic potential of strain EC121, an extensive genome sequencing and in vitro characterization of various pathogenicity-associated properties were performed. The genomic analysis showed that strain EC121 harbors more than 50 complete virulence genetic clusters. It also displays the capacity to adhere to a variety of epithelial cell lineages and invade T24 bladder cells, as well as the ability to form biofilms on abiotic surfaces, and survive the bactericidal serum complement activity. Additionally, EC121 was shown to be virulent in the Galleria mellonella model. Furthermore, EC121 is an MDR strain harboring 14 antimicrobial resistance genes, including blaCTX-M-2. Completing the scenario, it belongs to serotype O154:H25 and to sequence type 101-B1, which has been epidemiologically linked to extraintestinal infections as well as to antimicrobial resistance spread. This study with E. coli strain EC121 shows that clinical isolates considered opportunistic might be true pathogens that go underestimated.

Protective effects of indigenous Escherichia coli against a pathogenic E. coli challenge strain in pigs

2017 ◽  
Vol 8 (5) ◽  
pp. 779-783 ◽  
Author(s):  
W. Vahjen ◽  
T. Cuisiniere ◽  
J. Zentek
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Coli Strain ◽  
Protective Effects ◽  
Macconkey Agar ◽  
Challenge Strain ◽  
E Coli ◽  
Pathogenic Factors

To investigate the inhibitory effect of indigenous enterobacteria on pathogenic Escherichia coli, a challenge trial with postweaning pigs was conducted. A pathogenic E. coli strain was administered to all animals and their health was closely monitored thereafter. Faecal samples were taken from three healthy and three diarrhoeic animals. Samples were cultivated on MacConkey agar and isolates were subcultured. A soft agar overlay assay was used to determine the inhibitory activity of the isolates. A total of 1,173 enterobacterial isolates were screened for their ability to inhibit the E. coli challenge strain. Colony forming units of enterobacteria on MacConkey agar were not different between healthy and diarrhoeic animals in the original samples. Furthermore, numbers of isolates per animal were also not significantly different between healthy (482 isolates) and diarrhoeic animals (691 isolates). A total of 43 isolates (3.7%) with inhibitory activity against the pathogenic E. coli challenge strain were detected. All inhibitory isolates were identified as E. coli via MALDI-TOF. The isolates belonged to the phylotypes A, C and E. Many isolates (67.4%) were commensal E. coli without relevant porcine pathogenic factors, but toxin- and fimbrial genes (stx2e, fae, estIb, elt1a, fas, fan) were detected in 14 inhibitory isolates. Healthy animals showed significantly (P=0.003) more inhibitory isolates (36 of 482 isolates; 7.5%) than diseased animals (7 of 691 isolates; 1.0%). There were no significant correlations regarding phylotype or pathogenic factors between healthy and diseased animals. This study has shown that a small proportion of indigenous E. coli is able to inhibit in vitro growth of a pathogenic E. coli strain in pigs. Furthermore, healthy animals possess significantly more inhibitory E. coli strains than diarrhoeic animals. The inhibition of pathogenic E. coli by specific indigenous E. coli strains may be an underlying principle for the containment of pathogenic E. coli in pigs.

scholarly journals Human Neutrophil Chemotaxis Is Modulated by Capsule and O Antigen from an Extraintestinal Pathogenic Escherichia coli Strain

2003 ◽  
Vol 71 (11) ◽  
pp. 6435-6445 ◽  
Author(s):  
Thomas A. Russo ◽  
Bruce A. Davidson ◽  
Diana M. Topolnycky ◽  
Ruth Olson ◽  
Stacy A. Morrill ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ex Vivo ◽  
Specific Antigen ◽  
Lavage Fluid ◽  
Coli Strain ◽  
Neutrophil Chemotaxis ◽  
Gram Negative ◽  
E Coli ◽  
O Antigen

ABSTRACT Gram-negative enteric bacilli, such as Escherichia coli, are common causes of nosocomial pneumonia. The interaction between pulmonary neutrophils and the infecting pathogen is a critical step in determining the outcome. Previous studies from our laboratory, for which a rat model of pneumonia was used, established that pulmonary neutrophil recruitment was modulated by the E. coli virulence factors capsule and O-specific antigen. To begin to understand the mechanism by which this recruitment occurs, we conducted in vitro and ex vivo chemotaxis assays, for which we used a clinically relevant E. coli isolate (CP9) and isogenic derivatives that were deficient in only the O antigen (CP921) or capsule (CP9.137) as chemoattractants with or without the high-affinity N-formylmethionyl-leucyl-phenylalanine receptor antagonist N-tert-butoxycarbonyl-methionine-leucine-phenylalanine (N-t-BOC). Given that only live E. coli was used for the initial in vitro chemotaxis assays, it was predicted that only N-t-BOC-sensitive chemotaxis would occur. However, both N-t-BOC-sensitive and -insensitive chemotaxis was observed. N-t-BOC-insensitive chemotaxis was mediated in part by interleukin 8, which was produced by neutrophils that had migrated toward E. coli. N-t-BOC-insensitive chemotaxis was only observed when live E. coli bacteria, not cell-free E. coli culture supernatants, were used as chemoattractants, suggesting that a direct E. coli-neutrophil interaction was necessary. The presence of both capsule and O antigen diminished total, N-t-BOC-sensitive, and N-t-BOC-insensitive neutrophil chemotaxis in vitro. The presence of capsule significantly decreased total, N-t-BOC-sensitive, and N-t-BOC-insensitive neutrophil chemotaxis ex vivo when cell-free bronchoalveolar lavage fluid from infected rats was used as the source of chemotactic factors. These effects of E. coli capsule and O antigen on neutrophil chemotaxis are novel, and they expand our understanding of the mechanisms by which these virulence traits contribute to the pathogenesis of gram-negative pneumonia and other extraintestinal infections.

scholarly journals Ciprofloxacin Treatment Failure in a Murine Model of Pyelonephritis Due to an AAC(6′)-Ib-cr-Producing Escherichia coli Strain Susceptible to CiprofloxacinIn Vitro

2013 ◽  
Vol 57 (12) ◽  
pp. 5830-5835 ◽  
Author(s):  
T. Guillard ◽  
E. Cambau ◽  
F. Chau ◽  
L. Massias ◽  
C. de Champs ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Murine Model ◽  
Resistance Mechanism ◽  
Bacterial Count ◽  
Coli Strain ◽  
Content Type ◽  
E Coli ◽  
Fixed Concentration

ABSTRACTAAC(6′)-Ib-cr is a plasmid-mediated quinolone resistance mechanism described worldwide forEscherichia coli. Since it confersin vitroonly a low level of resistance to ciprofloxacin, we evaluated its impact on thein vivoactivity of ciprofloxacin. Isogenic strains were obtained by transferring plasmid p449, harboringaac(6′)-Ib-cr, into the quinolone-susceptible strainE. coliCFT073-RR and its D87GgyrAmutant. MICs were 0.015, 0.06, 0.25, and 0.5 μg/ml againstE. colistrains CFT073-RR, CFT073-RR/p449, CFT073-RR GyrAr, and CFT073-RR GyrAr/p449, respectively. Bactericidal activity was reduced at 1× the MIC for the three resistant derivatives, while at a fixed concentration of 0.5 μg/ml, 99.9% killing was observed for all strains exceptE. coliCFT073-RR GyrAr/p449. In the murine model of pyelonephritis, an optimal regimen of ciprofloxacin (10 mg/kg of body weight twice a day [b.i.d.]) significantly decreased the bacterial count in the kidneys of mice infected withE. coliCFT073 (1.6 versus 4.3 log10CFU/g of kidney compared to untreated controls;P= 0.0001), while no significant decrease was observed forE. coliCFT073-RR/p449 (2.7 versus 3.1 log10CFU/g;P= 0.84),E. coliCFT073-RR GyrAr(4.2 versus 4.1 log10CFU/g;P= 0.35), orE. coliCFT073-RR GyrAr/p449 (2.9 versus 3.6 log10CFU/g;P= 0.47). While pharmacokinetic and pharmacodynamic (PK/PD) parameters accounted for ciprofloxacin failure againstgyrA-containing mutants, this was not the case for theaac(6′)-Ib-cr-containing strains, suggesting anin situhydrolysis of ciprofloxacin in the latter case.

scholarly journals Demonstration of the Pre–Emergency Use Authorization Path Using 3 Minor Groove Binder–Hydrolysis Probe Assays to Detect Escherichia coli O104:H4

2015 ◽  
Vol 61 (11) ◽  
pp. 1391-1398 ◽  
Author(s):  
Laurie J Hartman ◽  
Megan L Heinrich ◽  
Ashley M Zovanyi ◽  
Michael F Ingram ◽  
J Peyton Hobson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Department Of Defense ◽  
Emergency Preparedness ◽  
Coli Strain ◽  
Minor Groove Binder ◽  
E Coli ◽  
Us Government ◽  
In Vitro Diagnostic ◽  
Public Health Emergency Preparedness

Abstract BACKGROUND The Department of Defense (DoD) and the Food and Drug Administration (FDA) have collaboratively worked on a pre–Emergency Use Authorization (pre-EUA) process for in vitro diagnostic (IVD) devices, using FDA's regulatory flexibilities under the EUA authorities. The pre-EUA process enables FDA review of data in anticipation of a request for an EUA, advancing US government public health emergency preparedness efforts. METHODS The IVD device developed to detect Escherichia coli O104:H4, for which an EUA has not been issued, serves as an example to illustrate that process. Specifically, DoD designed real-time PCR assays to target the virulent E. coli strain O104:H4 (etiological agent of the 2011 German outbreak) including: fliC (flagellin), Agg3C (AAF), and rfb (wbwC) on the basis of the published sequences. RESULTS After development and optimization of these 3 specific assays, a defined protocol was followed to determine and document the sensitivity and specificity of each assay analytically. CONCLUSIONS FDA reviewed these data and returned commentary on additional required experiments to complete the pre-EUA process and expedite the use of the device should there be an emergency need for an IVD device to detect this virulent E. coli strain before such a test is cleared by FDA.

scholarly journals Sub-lethal Concentrations of Phytochemicals (Carvacrol and Oregano) Select for Reduced Susceptibility Mutants of Escherichia coli O23:H52

2020 ◽  
Vol 69 (1) ◽  
pp. 121-125
Author(s):  
AFNAN A. AL-MNASER ◽  
MARTIN J. WOODWARD
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Coli Strain ◽  
Whole Genome ◽  
Avian Pathogenic Escherichia Coli ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Survival Mechanisms

In vitro studies aimed at studying the mechanism of action of carvacrol and oregano as natural anti-bacterial agents to control multiple antibiotic-resistant avian pathogenic Escherichia coli (APEC) strain O23:H52 isolated from chicken were performed. Derivatives with increased minimum inhibitory concentrations (MIC) to the phytochemicals were selected after growing Escherichia coli (E. coli) strain O23:H52 at sub-lethal concentrations of carvacrol and oregano for a period of 60 days. Whole-genome sequencing (WGS) of two derivatives revealed a missense mutation in cadC and marR: the genes responsible for survival mechanisms and antibiotic resistance by efflux, respectively.

scholarly journals Citrate synthase from Mycobacterium smegmatis. Cloning, sequence determination and expression in Escherichia coli

1991 ◽  
Vol 278 (1) ◽  
pp. 225-234 ◽  
Author(s):  
M David ◽  
S Lubinsky-Mink ◽  
A Ben-Zvi ◽  
M Suissa ◽  
S Ulitzur ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Binding Site ◽  
Mycobacterium Smegmatis ◽  
Citrate Synthase ◽  
Coli Strain ◽  
Ribosome Binding Site ◽  
E Coli ◽  
Ribosome Binding ◽  
Lac Promoter

A Mycobacterium smegmatis PstI library was constructed by cloning these fragments downstream from the lac promoter of the expression vector pHG171. Three identically sized clones were isolated by complementation of an Escherichia coli strain (chi 2338) deficient in citrate synthase. One insert (pBL265) was used in hybridization experiments with DNA from E. coli and M. smegmatis and it was demonstrated that the clones were indeed from M. smegmatis. The transcription of the M. smegmatis citrate synthase gene in E. coli relied upon the lac promoter. In translation experiments performed in vitro pBL265 gave rise to a novel protein of about 42 kDa. This band was not seen in ‘opposite-orientation’ subclones. Various subclones in which the 5′-end was shortened nevertheless complement E. coli chi 2338 and produce the 42 kDa protein. This demonstrates that the M. smegmatis citrate synthase gene uses its own ribosome-binding site in E. coli. The relevant 1.8 kb of the 2.8 kb insert was sequenced. A consensus E. coli ribosome-binding site was found centred precisely 10 bp upstream of the methionine codon. Other interesting features revealed by the sequence are discussed. Citrate synthase activity was assayed in vitro and the mycobacterial enzyme was found to be similar to those of the Gram-positive bacteria.

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