Effects of Diacetyl and Carbon Dioxide on Spoilage Microflora in Ground Beef

2002 ◽  
Vol 65 (3) ◽  
pp. 523-527 ◽  
Author(s):  
ANISHA M. WILLIAMS-CAMPBELL ◽  
JAMES M. JAY
Keyword(s):  
Ground Beef ◽  
Plate Count ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Plate Count Agar ◽  
Plate Counts ◽  
Meat Samples ◽  
Spoilage Microflora

The effect of CO2 and diacetyl, alone or in combination, on spoilage microflora in ground beef was determined. Ground beef was treated with 20, 30, or 40% CO2 for 22 days (study I); 20, 50, or 100 μg/g diacetyl for 26 days (study II); or a combination of 20% CO2 and 100 μg/g diacetyl for 40 days (study III). Antimicrobial effectiveness was determined by aerobic plate counts (log10 CFU/g) using plate count agar (total aerobic bacteria), deMan Rogosa Sharpe (MRS) Lactobacillus agar (gram-positive bacteria), MacConkey agar (gram-negative bacteria), pH, and informal organoleptic assessments (by appearance and by odor). In study I, total bacteria and pH increased by day 4 in control meat samples. For all CO2 levels, gram-negative bacteria decreased and gram-positive bacteria increased compared with untreated controls. The pH remained constant for CO2-treated meat. Control samples had an off-odor and a brown appearance, while CO2-treated samples had no off-odor but did have a brown appearance. For samples treated with diacetyl (study II), spoilage was evident by day 7 for samples treated with 0, 20, and 50 μg/g diacetyl for all parameters examined. Ground beef treated with 100 μg/g diacetyl was spoiled on day 12. Diacetyl was detected (by odor) in samples that were treated with 100 μg/g diacetyl and had a brown appearance. Meat samples treated with the combination of CO2 and diacetyl (study III) showed that the addition of diacetyl did not have an additive effect on microbial growth. Combination-treated meat maintained a red appearance and no off-odor. Diacetyl and CO2 could be used in combination to maintain a red color and inhibit spoilage microorganisms.

Antimicrobial Properties of α-Dicarbonyl and Related Compounds

1983 ◽  
Vol 46 (4) ◽  
pp. 325-329 ◽  
Author(s):  
J. M. JAY ◽  
G. M. RIVERS ◽  
W. E. BOISVERT
Keyword(s):  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Broth Culture ◽  
Plate Count ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Plate Count Agar ◽  
Enzyme Substrate

By surface plating on plate count agar, 0.005 M (430 ppm) of the α-dicarbonyl compound, diacetyl, inhibited 28 of 40 organisms with the medium at pH 6 but only 11 at pH 8. Diacetyl was more effective against gram-negative bacteria and yeasts than non-lactic gram-positive bacteria and least effective against lactic acid bacteria. Acetoin, butanedioldiacetate and five butanediol isomers were considerably less effective than diacetyl, although all were more effective at pH 6 than 8. Diacetylmonoxime and diacetyldioxime were more effective than the diols and were less affected by pH of medium than diacetyl. Phenylglyoxal (PG) and 1,2-cyclohexanedione (CHD) ranked closest to diacetyl but, unlike the latter, they were more effective against gram-positive bacteria and less so against fungi and gram-negative bacteria. All 12 compounds were more effective against selected organisms by pour plating and in broth culture than by surface plating. Like diacetyl, CHD and PG are α, α-dicarbonyls and are widely used as arginine reactive agents resulting in the blockage of enzyme-substrate reactions. Although their antimicrobial activity may be due to this property, they apparently affect different enzymes than diacetyl because their antimicrobial spectra were different. The possibility of a class of food-use antimicrobial agents bearing α-dicarbonyl groups is suggested by the findings of this study.

Rapid Estimation of Microbial Numbers in Fresh Ground Beef by Use of the Limulus Test

1981 ◽  
Vol 44 (4) ◽  
pp. 275-278 ◽  
Author(s):  
JAMES M. JAY
Keyword(s):  
Ground Beef ◽  
Gram Negative Bacteria ◽  
Confidence Limits ◽  
Rapid Estimation ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Limulus Amoebocyte Lysate ◽  
Plate Counts ◽  
The Mean ◽  
Microbial Numbers

From 153 samples of fresh ground beef, aerobic plate counts (APC) and counts of viable gram-negative bacteria (GNB) were determined along with ng of endotoxin/g by use of the Limulus amoebocyte lysate (LAL) test. When the 153 meats were grouped by one-half log cycle ranges beginning with samples that contained < log 4.00 GNB/g, they were placed into eight groups. Mean ng endotoxin for these groups increased from 14 for the five samples with GNB < log 4.00 to 52,340 for the 16 samples with log GNB from 7.00 to 7.49. The APC to GNB ratios for the 13 meats with log GNB between 4.00 – 4.49 was 21, but decreased steadily to 2.2 for the 16 with log GNB of 7.00 – 7.49/g, reflecting the progressive decrease in the proportions of gram-positive bacteria and yeasts as total viable counts increased. The mean number of viable GNB/ng of total endotoxin for 148 of these samples was 1900. To calculate the number of GNB in a sample, the latter value was multiplied by the LAL-determined endotoxin in the sample. When GNB/g was multiplied by the respective APC to GNB ratio values, the approximate APC/g was derived. Although the variance and confidence limits of some of the APC and GNB ratio values were wide, use of LAL to estimate APC in 1 h was found to be workable.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

BAKTERI PADA KARANG SCLERACTINIA DI KAWASAN PERAIRAN BUNAKEN, MOROTAI DAN RAJA AMPAT

2020 ◽  
Vol 8 (1) ◽  
pp. 122
Author(s):  
Eghbert Eghbert Elvan Eghbert Elvan Ampou ◽  
Iis Iis Triyulianti ◽  
Nuryani Widagti ◽  
Suciadi Catur Nugroho ◽  
Yuli Pancawati
Keyword(s):  
Scleractinian Coral ◽  
Gram Negative Bacteria ◽  
Hard Coral ◽  
Field Sampling ◽  
Bacterial Isolation ◽  
Gram Positive ◽  
Coral Mucus ◽  
Gram Negative ◽  
Gram Positive Bacteria

Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of gram-positive and gram-negative bacteria. The method used for field sampling is time swim, which is by diving at a depth of 5-10 meters for ± 30 minutes and randomly taking samples of coral mucus using siring or by taking directly on corals (reef branching). Mucus samples were analyzed by bacterial isolation in the laboratory. The result shows that there were differences between gram-positive and gram-negative bacteria in the three research sites and that gram-positive bacteria were higher or dominant. Further research that can identify the bacteria species and explain its relationship to the ecosystem is highly recommended.Keywords: Bacteria, Scleractinian coral, gram-positive and -negative, Bunaken, Morotai, Raja Ampat  AbstrakPenelitian tentang karang keras (Scleractinian coral) yang terkontaminasi bakteri masih belum banyak dilakukan, terutama di perairan Indonesia. Penelitian ini mengambil sampel mucus karang pada tahun 2010 di 3 (tiga) lokasi berbeda, yakni Bunaken (Mei); Morotai (September) dan Raja Ampat (November), yang difokuskan pada analisis bakteri gram postif dan gram negatif. Metode yang digunakan untuk pengambilan sampel di lapangan adalah time swim, yaitu dengan penyelaman pada kedalaman 5-10 meter selama ±30 menit dan mengambil sampel mucus karang secara acak menggunakan siring atau dengan mengambil langsung pada karang (fraksi cabang). Sampel mucus dianalisis dengan cara isolasi bakteri di laboratorium. Hasil analisis menunjukkan bahwa ada perbedaan antara bakteri gram positif dan gram negative di tiga lokasi survei dan bakteri gram positif lebih tinggi atau dominan. Penelitian lebih lanjut yang dapat menentukan jenis bakteri serta menjelaskan hubungannya dengan ekosistem sangat disarankan untuk dilakukan.Kata Kunci : Bakteri, Scleractinian coral, gram positif dan negatif, Bunaken, Morotai, Raja Ampat

scholarly journals N-Doped Carbon Quantum Dots as Fluorescent Bioimaging Agents

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 789
Author(s):  
Shih-Fu Ou ◽  
Ya-Yun Zheng ◽  
Sin-Jen Lee ◽  
Shyi-Tien Chen ◽  
Chien-Hui Wu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Nanomaterials ◽  
Graphene Quantum Dots ◽  
Carbon Quantum Dots ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Fluorescence Characteristics ◽  
And Staphylococcus Aureus

Graphene quantum dots, carbon nanomaterials with excellent fluorescence characteristics, are advantageous for use in biological systems owing to their small size, non-toxicity, and biocompatibility. We used the hydrothermal method to prepare functional N-doped carbon quantum dots (N-CQDs) from 1,3,6-trinitropyrene and analyzed their ability to fluorescently stain various bacteria. Our results showed that N-CQDs stain the cell septa and membrane of the Gram-negative bacteria Escherichia coli, Salmonellaenteritidis, and Vibrio parahaemolyticus and the Gram-positive bacteria Bacillus subtilis, Listeria monocytogenes, and Staphylococcus aureus. The optimal concentration of N-CQDs was approximately 500 ppm for Gram-negative bacteria and 1000 ppm for Gram-positive bacteria, and the exposure times varied with bacteria. N-Doped carbon quantum dots have better light stability and higher photobleaching resistance than the commercially available FM4-64. When excited at two different wavelengths, N-CQDs can emit light of both red and green wavelengths, making them ideal for bioimaging. They can also specifically stain Gram-positive and Gram-negative bacterial cell membranes. We developed an inexpensive, relatively easy, and bio-friendly method to synthesize an N-CQD composite. Additionally, they can serve as a universal bacterial membrane-staining dye, with better photobleaching resistance than commercial dyes.

scholarly journals Gram-positive bacteria cell wall-derived lipoteichoic acid induces inflammatory alveolar bone loss through prostaglandin E production in osteoblasts

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tsukasa Tominari ◽  
Ayumi Sanada ◽  
Ryota Ichimaru ◽  
Chiho Matsumoto ◽  
Michiko Hirata ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bone Loss ◽  
Alveolar Bone ◽  
Osteoclast Differentiation ◽  
Lipoteichoic Acid ◽  
Alveolar Bone Loss ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

AbstractPeriodontitis is an inflammatory disease associated with severe alveolar bone loss and is dominantly induced by lipopolysaccharide from Gram-negative bacteria; however, the role of Gram-positive bacteria in periodontal bone resorption remains unclear. In this study, we examined the effects of lipoteichoic acid (LTA), a major cell-wall factor of Gram-positive bacteria, on the progression of inflammatory alveolar bone loss in a model of periodontitis. In coculture of mouse primary osteoblasts and bone marrow cells, LTA induced osteoclast differentiation in a dose-dependent manner. LTA enhanced the production of PGE2 accompanying the upregulation of the mRNA expression of mPGES-1, COX-2 and RANKL in osteoblasts. The addition of indomethacin effectively blocked the LTA-induced osteoclast differentiation by suppressing the production of PGE2. Using ex vivo organ cultures of mouse alveolar bone, we found that LTA induced alveolar bone resorption and that this was suppressed by indomethacin. In an experimental model of periodontitis, LTA was locally injected into the mouse lower gingiva, and we clearly detected alveolar bone destruction using 3D-μCT. We herein demonstrate a new concept indicating that Gram-positive bacteria in addition to Gram-negative bacteria are associated with the progression of periodontal bone loss.

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

Children ◽  
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.

scholarly journals Enaminone-Derived Pyrazoles with Antimicrobial Activity

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mashooq Ahmad Bhat ◽  
Mohamed A. Al-Omar ◽  
Ahmed M. Naglah ◽  
Abdul Arif Khan
Keyword(s):  
Antimicrobial Activity ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Disc Diffusion ◽  
Initial Screening ◽  
Gram Positive ◽  
Gram Negative ◽  
Disc Diffusion Assay ◽  
Gram Positive Bacteria ◽  
Diffusion Assay

A series of pyrazoles derived from the substituted enaminones were synthesized and were evaluated for antimicrobial activity. All the compounds were characterized by the spectral data and elemental analysis. The synthesized compounds were initially screened for their antimicrobial activity against ATCC 6538, NCTC 10400, NCTC 10418, and ATCC 27853. During initial screening, compounds (P1, P6, and P11) presented significant antimicrobial activity through disc diffusion assay. These compounds were further evaluated for antimicrobial activity at different time points against Gram-positive and Gram-negative bacteria and presented significant activity for 6 hours. The activity was found to be greater against Gram-positive bacteria. In contrast at 24 hours, the activity was found only against Gram-positive bacteria except compound (P11), showing activity against both types of bacteria. Compound (P11) was found to have highest activity against both Gram-positive and Gram-negative bacteria.

scholarly journals In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
The Other ◽  
Vitro Activity ◽  
Gram Negative Bacteria ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.

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