RELATIONSHIP BETWEEN FOOD CONTACT TIME TO THE EFFECT ON TRANSFER OF MICROBES FROM CERAMIC FLOOR USING THE FIVE-SECOND RULE

Eosin-Methylene Blue (EMB) in order to isolate gram-negative bacteria (Escherichia coli) as the contamination level indicator. Microbes identified with gram staining and observed under a light microscope. The result reported into 5 categories: microbes were founded or not in the petri dishes, determine whether lactose fermentation/acid production can be observed, grade the microbes concentration founded in the petri dishes (grade 1-6), classify the level of contamination (low-high), describing colonies shape in EMB agar and identifying the microbes with gram staining. The results was at the student center’s canteen 3 of 5 samples under 5 seconds are positive and 5 of 7 samples until 300 seconds are positive. The level of contamination was inconsistent with increasing time. Whereas in the diagnostic center’s canteen 12 of 12 samples were all positives, regardless of time. In conclusion, the five-second rule is a significant oversimplification of what actually happens when bacteria transfer from a surface to food. Risk of transfer of contamination is constantly present regardless of time.

Download Full-text

Kualitas Air Sumur Bor dan Air Swadaya Berdasarkan Total Coliform dengan Cemaran Escherichia coli di Desa Rarowatu Kabupaten Bombana

BioWallacea : Jurnal Penelitian Biologi (Journal of Biological Research) ◽

10.33772/biowallacea.v6i1.8745 ◽

2019 ◽

Vol 6 (1) ◽

Author(s):

Angriani Fusvita ◽

Susanti Susanti ◽

Bobi Anggriawan

Keyword(s):

Escherichia Coli ◽

Methylene Blue ◽

Water Samples ◽

Total Coliform ◽

Most Probable Number ◽

Biochemical Tests ◽

Probable Number ◽

Gram Negative ◽

Gram Staining ◽

Quality Of Water

Penelitian ini bertujuan untuk mengetahui kualitas Air di Desa Rarowatu Kabupaten Bombana. Pemeriksaan coliform pada air sumur bor dan air swadaya masyarakat menggunakan Metode Most Probable Number (MPN). Pada perlakuan ini terdiri dari presumptive test yang menggunakan media Lactose Broth (LB) dengan metode 3 seri tabung, Tahap berikutnya confirmative test dengan menggunakan media Brillian Green Lactose Broth (BGLB). Pada identifikasi Escherichia coli menggunakan media Eosin Methylene Blue Agar, pewarnaan Gram dan media uji biokimia. Hasil penelitian menunjukkan sampel yang terdiri dari 7 sampel air sumur bor dan I sampel air swadaya masyarakat berdasarkan uji MPN mencapai 2400/100 ml. Hasil identifikasi menggunakan media EMBA menunjukkan koloni yang berwarna hijau metalik pada sampel air swadaya serta dilakukan pewarnaan Gram menunjukkan bentuk basil pendek dan gram negative. Hasil uji biokimia menunjukkan hasil uji indol positif, methyl red positif, voges proskauer negatif dan uji sitrat negatif. Uji IMViC dapat disimpulkan bahwa bakteri pada kode sampel D memiliki sifat yang sama terhadap bakteri E. coli. Kata kunci : Coliform, Identifikasi, Escherichia coli, BombanaABSTRACTThis study aims to determine the quality of water in Rarowatu Village, Bombana Regency. Coliform examination in borehole water and community self-water using the Most Probable Number (MPN) Method. This treatment consists of a presumptive test that uses Lactose Broth (LB) media with the tube 3 series method. The next stage is the confirmative test using Brilliant Green Lactose Broth (BGLB) media. The identification of Escherichia coli using Eosin Methylene Blue Agar media, Gram staining, and biochemical test media. The results of the study showed that samples consisting of 7 samples of bore well water and I community self-water samples based on the MPN test reached 2400/100 ml. The identification results using EMBA media showed that metallic green colonies in self-help water samples and Gram staining performed showed short and gram-negative bacilli forms. The results of biochemical tests showed that swadaya water samples were Escherichia coli species.Keywords: Coliform, Identification, Escherichia coli, Bombana

Download Full-text

Dual stain kit for the microscopic gram classification of ocular infection bacteria

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100147089 ◽

1993 ◽

Vol 51 ◽

pp. 248-249

Author(s):

Jacob S. Hanker ◽

Dale N. Holdren ◽

Kenneth L. Cohen ◽

Beverly L. Giammara

Keyword(s):

Contact Lenses ◽

Ocular Infection ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Gram Staining ◽

Ocular Infections ◽

Different Types ◽

Culture Positive ◽

Increased Susceptibility

Keratitis and conjunctivitis (infections of the cornea or conjunctiva) are ocular infections caused by various bacteria, fungi, viruses or parasites; bacteria, however, are usually prominent. Systemic conditions such as alcoholism, diabetes, debilitating disease, AIDS and immunosuppressive therapy can lead to increased susceptibility but trauma and contact lens use are very important factors. Gram-negative bacteria are most frequently cultured in these situations and Pseudomonas aeruginosa is most usually isolated from culture-positive ulcers of patients using contact lenses. Smears for staining can be obtained with a special swab or spatula and Gram staining frequently guides choice of a therapeutic rinse prior to the report of the culture results upon which specific antibiotic therapy is based. In some cases staining of the direct smear may be diagnostic in situations where the culture will not grow. In these cases different types of stains occasionally assist in guiding therapy.

Download Full-text

Antimicrobial and cytotoxic activity of Macrophomina phaseolina isolated from gummosis infected citrus reticulata

Chittagong University Journal of Biological Sciences ◽

10.3329/cujbs.v5i1.13378 ◽

2013 ◽

pp. 125-133

Author(s):

Rubal C Das ◽

Rajib Banik ◽

Robiul Hasan Bhuiyan ◽

Md Golam Kabir

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Brine Shrimp ◽

Inhibitory Concentration ◽

Lethal Dose ◽

Macrophomina Phaseolina ◽

Chloroform Extract ◽

Citrus Reticulata ◽

Gram Negative Bacteria ◽

Gram Negative

Macrophomina phaseolina is one of the pathogenic organisms of gummosis disease of orange tree (Citrus reticulata). The pathogen was identified from the observation of their colony size, shape, colour, mycelium, conidiophore, conidia, hyaline, spore, and appressoria in the PDA culture. The crude chloroform extracts from the organism showed antibacterial activity against a number of Gram positive and Gram-negative bacteria. The crude chloroform extract also showed promising antifungal activity against three species of the genus Aspergillus. The minimum inhibitory concentration (MIC) of the crude chloroform extract from M. phaseolina against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Shigella sonnie were 128 ?gm, 256 ?gm, 128 ?gm and 64 ?gm/ml respectively. The LD50 (lethal dose) values of the cytotoxicity assay over brine shrimp of the crude chloroform extract from M. phaseolina was found to be 51.79 ?gm/ml. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13378 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):125-133, 2010

Download Full-text

Endotoxin of the gram-negative bacteria (Escherichia coli) as a trigger factor in development of HLA-B27 associated anterior uveitis

Oftalmologicheskii Zhurnal ◽

10.31288/oftalmolzh201052023 ◽

2010 ◽

Vol 27 (5) ◽

pp. 20-23

Author(s):

A. I Kopayenko ◽

Keyword(s):

Escherichia Coli ◽

Anterior Uveitis ◽

Trigger Factor ◽

Gram Negative Bacteria ◽

Hla B27 ◽

Gram Negative

Download Full-text

Protein secretion in gram-negative bacteria. The extracellular metalloprotease B from Erwinia chrysanthemi contains a C-terminal secretion signal analogous to that of Escherichia coli alpha-hemolysin.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)44877-0 ◽

1990 ◽

Vol 265 (28) ◽

pp. 17118-17125 ◽

Cited By ~ 4

Author(s):

P Delepelaire ◽

C Wandersman

Keyword(s):

Escherichia Coli ◽

Protein Secretion ◽

Erwinia Chrysanthemi ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Secretion Signal ◽

Alpha Hemolysin

Download Full-text

Proteomic response of Escherichia coli to a membrane lytic and iron chelating truncated Amaranthus tricolor defensin

BMC Microbiology ◽

10.1186/s12866-021-02176-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Tessa B. Moyer ◽

Ashleigh L. Purvis ◽

Andrew J. Wommack ◽

Leslie M. Hicks

Keyword(s):

Escherichia Coli ◽

Antibacterial Activity ◽

Antimicrobial Peptides ◽

Mechanism Of Action ◽

Gram Negative Bacteria ◽

Amaranthus Tricolor ◽

Core Motif ◽

Gram Negative ◽

E Coli ◽

Membrane Lysis

Abstract Background Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. Results Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. Conclusions This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.

Download Full-text

MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa

International Journal of Molecular Sciences ◽

10.3390/ijms22105328 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5328

Author(s):

Miao Ma ◽

Margaux Lustig ◽

Michèle Salem ◽

Dominique Mengin-Lecreulx ◽

Gilles Phan ◽

...

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Cell Division ◽

Membrane Proteins ◽

Outer Membrane ◽

Efflux Pump ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Active Efflux

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.

Download Full-text

Pyelonephritis in Pediatric Uropathic Patients: Differences from Community-Acquired Ones and Therapeutic Protocol Considerations. A 10-Year Single-Center Retrospective Study

Children ◽

10.3390/children8060436 ◽

2021 ◽

Vol 8 (6) ◽

pp. 436

Author(s):

Giovanni Parente ◽

Tommaso Gargano ◽

Stefania Pavia ◽

Chiara Cordola ◽

Marzia Vastano ◽

...

Keyword(s):

Escherichia Coli ◽

Retrospective Study ◽

Success Rate ◽

Pediatric Population ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Significant Difference ◽

Klebsiella Spp

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.

Download Full-text

A High-Throughput Approach To Identify Compounds That Impair Envelope Integrity in Escherichia coli

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00537-16 ◽

2016 ◽

Vol 60 (10) ◽

pp. 5995-6002 ◽

Cited By ~ 7

Author(s):

Kristin R. Baker ◽

Bimal Jana ◽

Henrik Franzyk ◽

Luca Guardabassi

Keyword(s):

Escherichia Coli ◽

High Throughput ◽

High Throughput Screening ◽

Gram Negative Bacteria ◽

Chromogenic Substrate ◽

Intrinsic Resistance ◽

Gram Negative ◽

Content Type ◽

E Coli ◽

Screening Platform

ABSTRACTThe envelope of Gram-negative bacteria constitutes an impenetrable barrier to numerous classes of antimicrobials. This intrinsic resistance, coupled with acquired multidrug resistance, has drastically limited the treatment options against Gram-negative pathogens. The aim of the present study was to develop and validate an assay for identifying compounds that increase envelope permeability, thereby conferring antimicrobial susceptibility by weakening of the cell envelope barrier in Gram-negative bacteria. A high-throughput whole-cell screening platform was developed to measureEscherichia colienvelope permeability to a β-galactosidase chromogenic substrate. The signal produced by cytoplasmic β-galactosidase-dependent cleavage of the chromogenic substrate was used to determine the degree of envelope permeabilization. The assay was optimized by using known envelope-permeabilizing compounds andE. coligene deletion mutants with impaired envelope integrity. As a proof of concept, a compound library comprising 36 peptides and 45 peptidomimetics was screened, leading to identification of two peptides that substantially increased envelope permeability. Compound 79 reduced significantly (from 8- to 125-fold) the MICs of erythromycin, fusidic acid, novobiocin and rifampin and displayed synergy (fractional inhibitory concentration index, <0.2) with these antibiotics by checkerboard assays in two genetically distinctE. colistrains, including the high-risk multidrug-resistant, CTX-M-15-producing sequence type 131 clone. Notably, in the presence of 0.25 μM of this peptide, both strains were susceptible to rifampin according to the resistance breakpoints (R> 0.5 μg/ml) for Gram-positive bacterial pathogens. The high-throughput screening platform developed in this study can be applied to accelerate the discovery of antimicrobial helper drug candidates and targets that enhance the delivery of existing antibiotics by impairing envelope integrity in Gram-negative bacteria.

Download Full-text