High-frequency conjugal plasmid transfer from gram-negative Escherichia coli to various gram-positive coryneform bacteria.

Pyelonephritis (PN) represents an important cause of morbidity in the pediatric population, especially in uropathic patients. The aim of the study is to demonstrate differences between PNs of uropathic patients and PNs acquired in community in terms of uropathogens involved and antibiotic sensitivity; moreover, to identify a proper empiric therapeutic strategy. A retrospective study was conducted on antibiograms on urine cultures from PNs in vesicoureteral reflux (VUR) patients admitted to pediatric surgery department and from PNs in not VUR patients admitted to Pediatric Emergency Unit between 2010 and 2020. We recorded 58 PNs in 33 patients affected by VUR and 112 PNs in the not VUR group. The mean age of not VUR patients at the PN episode was 1.3 ± 2.6 years (range: 20 days of life–3 years), and almost all the urine cultures, 111 (99.1%), isolated Gram-negative bacteria and rarely, 1 (0.9%), Gram-positive bacteria. The Gram-negative uropathogens isolated were Escherichia coli (97%), Proteus mirabilis (2%), and Klebsiella spp. (1%). The only Gram-positive bacteria isolated was an Enterococcus faecalis. As regards the antibiograms, 96% of not VUR PNs responded to beta-lactams, 99% to aminoglycosides, and 80% to sulfonamides. For the VUR group, mean age was 3.0 years ± 3.0 years (range: 9 days of life–11 years) and mean number of episodes per patient was 2.0 ± 1.0 (range: 1–5); 83% of PNs were by Gram-negatives bacteria vs. 17% by Gram-positive: the most important Gram-negative bacteria were Pseudomonas aeruginosa (44%), Escherichia coli (27%), and Klebsiella spp. (12%), while Enterococcus spp. determined 90% of Gram-positive UTIs. Regimen ampicillin/ceftazidime (success rate: 72.0%) was compared to ampicillin/amikacin (success rate of 83.0%): no statistically significant difference was found (p = 0.09). The pathogens of PNs in uropathic patients are different from those of community-acquired PNs, and clinicians should be aware of their peculiar antibiotic susceptibility. An empiric therapy based on the association ampicillin + ceftazidime is therefore suggested.

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Microbial Kinetics of Drug Action against Gram-Positive and Gram-Negative Organisms I: Effect of Lincomycin on Staphylococcus aureus and Escherichia coli

Journal of Pharmaceutical Sciences ◽

10.1002/jps.2600630709 ◽

1974 ◽

Vol 63 (7) ◽

pp. 1077-1084 ◽

Cited By ~ 9

Author(s):

Samuel M. Heman-Ackah

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Drug Action ◽

Gram Positive ◽

Gram Negative ◽

Microbial Kinetics ◽

Gram Negative Organisms ◽

Kinetics Of

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A New Prenylated Flavanoid with Antibacterial Activity from Propolis Collected in Egypt

Natural Product Communications ◽

10.1177/1934578x1000500111 ◽

2010 ◽

Vol 5 (1) ◽

pp. 1934578X1000500 ◽

Cited By ~ 5

Author(s):

Ashraf El-Bassuony ◽

Sameh AbouZid

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Bacillus Cereus ◽

Spectroscopic Methods ◽

Gram Positive ◽

Gram Negative

A novel prenylated flavanoid, isonymphaeol-D (1), together with two known compounds, isonymphaeol-B (2) and nymphaeol-B (3), were isolated from Egyptian propolis. The structures of the isolated compounds were determined by various spectroscopic methods. 1 exhibited antibacterial activity against Gram-positive (Bacillus cereus, Staphylococcus aureus) and Gram-negative strains (Serratia sp., Pseudomonos sp., Escherichia coli).

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Microbial Flora of Preseasoned Comminuted Turkey Meat

Journal of Food Protection ◽

10.4315/0362-028x-40.5.322 ◽

1977 ◽

Vol 40 (5) ◽

pp. 322-324 ◽

Cited By ~ 1

Author(s):

LINDA S. GUTHERTZ ◽

JOHN T. FRUIN ◽

JAMES L. FOWLER

Keyword(s):

Escherichia Coli ◽

Microbial Contamination ◽

Microbial Flora ◽

Plate Count ◽

Gram Positive ◽

Gram Negative ◽

Turkey Meat ◽

Standard Plate Count ◽

Standard Plate

Preseasoned comminuted turkey meat, prepared at the retail level, was examined and revealed the following levels of microbial contamination per gram: mean standard plate count 2.2 × 108, mean coliform plate count 2.0 × 105, Escherichia coli count 8.7. Gram-positive and gram-negative microbial flora were isolated and identified.

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Inactivation of Escherichia coli and Staphyloccocus aureus in Litchi Juice by Dimethyl Dicarbonate (DMDC) Combined With Nisin

Journal of Food Research ◽

10.5539/jfr.v3n3p1 ◽

2014 ◽

Vol 3 (3) ◽

pp. 1 ◽

Cited By ~ 4

Author(s):

Yuanshan Yu ◽

Yujuan Xu ◽

Jijun Wu ◽

Gengsheng Xiao ◽

Jing Wen ◽

...

Keyword(s):

Escherichia Coli ◽

Synergistic Effect ◽

Ph Value ◽

Inactivation Rate ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Complete Inactivation ◽

Staphyloccocus Aureus ◽

Addition Level

Inactivation of Gram-negative Escherichia coli and Gram-positive Staphyloccocus aureus in litchi juice by DMDC combined with nisin was individually investigated. A 1.66 log cycles reduction of E. coli and 2.03 log cycles reduction of S. aureus in litchi juice (pH 4.5) added without nisin was achieved as exposed to 150 mg/l DMDC at 30 °C for 1 h, and the inactivation rate of E. coli and S. aureus during initial 1 h was far greater than during the remaining 5 h. As exposed to 150 mg/l DMDC at 30 °C for 1 h, the inactivation of E. coli and S. aureus in the litchi juice showed a trend toward increase with increasing of nisin addition level in the range from 0 to 200 IU/ml. Moreover, DMDC and nisin exhibited a synergistic effect on the inactivation of E. coli and S. aureus in litchi juice, and the inactivation of E. coli and S. aureus in the litchi juice also depends on the temperature of litchi juice, pH value of litchi juice and DMDC concentration when treated with DMDC and nisin. In addition, E. coli showed higher resistance to nisin as comparing with S. aureus. After E. coli and S. aureus in the litchi juice of pH 4.0 were individually treated with 150 mg/l DMDC combined with 200 IU/ml nisin at 30 °C for 1 h, a complete inactivation of S. aureus (6.59 log cycles) was achieved, but only 3.52 log cycles reduction of E. coli was observed.

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Antibacterial Activity of Amine-Functionalized Zeolite NaY against Staphylococcus aureus ATCC6538 and Escherichia coli ATCC11229

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.761.402 ◽

2015 ◽

Vol 761 ◽

pp. 402-406 ◽

Cited By ~ 3

Author(s):

Siti Aishah Mohd Hanim ◽

Nik Ahmad Nizam Nik Malek ◽

Zaharah Ibrahim ◽

Mashitah Mad Salim ◽

Nur Isti'anah Ramli ◽

...

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Inhibition Zone ◽

Antibacterial Activities ◽

Gram Positive ◽

Gram Negative ◽

Zeolite Nay ◽

Amine Functionalized ◽

Diffusion Technique

The antibacterial activity of functionalized zeolite NaY (CBV100) with different concentrations of 3-aminopropyltriethoxysilane (APTES) (0.01, 0.05, 0.20 and 0.40 M) was studied against Staphylococcus aureus ATCC 6538 (Gram positive) and Escherichia coli ATCC 11229 (Gram negative) through disc diffusion technique (DDT). The characterization of functionalized zeolite NaY with fourier transform infrared (FTIR) spectroscopy indicated the attachment of APTES on zeolite NaY. Through DDT, the inhibition zone of functionalized zeolite NaY increased proportionally to the amount of the amine-functional group attached onto zeolite NaY. Functionalized zeolite NaY showed higher antibacterial activity against Gram-positive compared to Gram-negative bacteria. It can be concluded from this study that amine-functionalized zeolite NaY shows evidence of antibacterial activities.

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Survival of some non-starter bacteria in naturally ripened and enzyme-accelerated Cheddar cheese

Journal of Dairy Research ◽

10.1017/s0022029900033380 ◽

1988 ◽

Vol 55 (4) ◽

pp. 597-602 ◽

Cited By ~ 5

Author(s):

Lydia Bautista ◽

Rohan G. Kroll

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Enterococcus Faecalis ◽

Enzyme System ◽

Cheddar Cheese ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Ripening Period ◽

Gram Positive Bacteria

SummaryEffects of the addition of a proteinase (Neutrase 1–5S) and a peptidase (aminopeptidase DP-102) as agents for accelerating the ripening of Cheddar cheese on the survival of some non-starter bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coliand aSalmonellasp.) were studied throughout a 4-month ripening period. The enzymes were found to have no significant effect on the survival of the Gram-positive bacteria but some significant effects were observed, at some stages of the ripening period, with the Gram-negative bacteria in that lower levels were recovered from cheeses treated with the enzyme system.

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Different Modes of Action of Naphthyridones in Gram-Positive and Gram-Negative Bacteria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.1.385-387.2006 ◽

2006 ◽

Vol 50 (1) ◽

pp. 385-387 ◽

Cited By ~ 16

Author(s):

Ed T. Buurman ◽

Kenneth D. Johnson ◽

Roxanne K. Kelly ◽

Kathy MacCormack

Keyword(s):

Escherichia Coli ◽

Haemophilus Influenzae ◽

Mode Of Action ◽

Bacterial Pathogens ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Modes Of Action

ABSTRACT Naphthyridones that were recently described as a class of translation inhibitors in gram-positive bacteria mediate their mode of action via GyrA in Haemophilus influenzae and Escherichia coli. These are the first examples of compounds in which modes of action in different bacterial pathogens are mediated through widely different targets.

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Antimicrobial activity of silver-coated hollow poly(methylmethacrylate) microspheres for water decontamination

Environmental Sciences Europe ◽

10.1186/s12302-021-00463-5 ◽

2021 ◽

Vol 33 (1) ◽

Author(s):

Dhiraj Dutta ◽

Swagata Goswami ◽

Rama Dubey ◽

Sanjai K. Dwivedi ◽

Amrit Puzari

Keyword(s):

Escherichia Coli ◽

Antimicrobial Activity ◽

Bacillus Subtilis ◽

Water Solution ◽

Water Disinfection ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Negative ◽

Antimicrobial Materials ◽

Vis Spectroscopy

Abstract Background Growing microbial resistance towards the existing antimicrobial materials appears as the greatest challenge for the scientific community and development of new antimicrobial materials has become an important research objective. Results In this work, antimicrobial activity of silver-coated hollow poly(methylmethacrylate) microspheres (PMB) having a diameter of 20–80 µm was evaluated against two bacterial strains, Gram-positive Bacillus subtilis (MTCC 1305) and Gram-negative Escherichia coli (MTCC 443). The polymeric PMMA microspheres were synthesized by solvent evaporation technique and were further coated with silver (Ag) under microwave irradiation on their outer surface using an electroless plating technique. It was observed that Ag was uniformly coated on the surface of microspheres. Characterization of the coated microspheres was performed using optical microscope (OMS), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), UV–Vis spectroscopy, FTIR spectroscopy and thermogravimetric analysis (TGA) techniques. We have shown that the silver-coated microspheres were potent bactericidal material for water as they are highly active against the tested microorganisms. The results of the antibacterial tests indicated that APMB particles showed enhanced inhibition rate for both Gram-positive and Gram-negative bacteria and also exhibited dose-dependent antibacterial ability. The diameters of zone of inhibition were14.3 ± 0.2 mm against B. subtilis and 15.2 ± 0.9 mm against E. coli at a concentration of 8 mg. At this concentration, total removal of both Bacillus subtilis and Escherichia coli was observed. The results of shake flask technique for a concentration of 8 mg showed no bacterial presence after 24 h in both the cases. In other words, the material acted efficiently in bringing down the bacterial count to zero level for the tested strains. During the experiments, we have also confirmed that use of this material for water disinfection does not cause leaching of silver ion in to the water solution. The material can be successfully regenerated by backwashing with water. Conclusions Considering the cost-effective synthesis, ability to regenerate and very low level of leaching of the material, it can be projected as an advanced material for water disinfection and antimicrobial application.

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Asymmetric one-pot synthesis of cyclopropanes

Macedonian Journal of Chemistry and Chemical Engineering ◽

10.20450/mjcce.2016.835 ◽

2016 ◽

Vol 35 (1) ◽

pp. 45

Author(s):

Naoufel Ben Hamadi ◽

Ahlem Guesmi ◽

Wided Nouira

Keyword(s):

Escherichia Coli ◽

Water Soluble ◽

Gram Negative Bacteria ◽

Protecting Group ◽

Gram Positive ◽

One Pot ◽

Gram Negative ◽

Activity Screening ◽

High Yields

Cycloaddition of the diazoalkanes to electron-deficient olefins (in situ) affords polysubstituted cyclopropanes in high yields (up to 85%). Deprotection of the ketal protecting group provided water-soluble cyclopropane-bearing carbohydrate in good yields. Antimicrobial activity screening of the synthesized compounds 8 and 9, utilizing a variety of Gram-positive (Staphylococcus aureus and Enterococcus fecalis), Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and yeast (Candida albicans), exhibited that all the prepared analogues acquire promising activities against both Gram-positive and Gram-negative bacteria especially compounds 9b and 9c (antimicrobial active agents against Gram-negative bacteria).

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