Sensitivities of Foodborne Pathogens to Pressure Changes

2006 ◽  
Vol 69 (1) ◽  
pp. 130-136 ◽  
Author(s):  
HAIQIANG CHEN ◽  
DONGSHENG GUAN ◽  
DALLAS G. HOOVER
Keyword(s):  
Foodborne Pathogens ◽  
Treatment Time ◽  
Shigella Flexneri ◽  
Gram Positive ◽  
Clear Trend ◽  
Gram Negative ◽  
Serovar Typhimurium ◽  
Ultrahigh Temperature ◽  
Pressure Resistance ◽  
Pressure Changes

Eight foodborne pathogens were suspended in ultrahigh-temperature whole milk and treated at pressure levels of 0.1 to 690 MPa at 21.5°C for 10 min. There was no clear trend in pressure resistance between gram-negative and gram-positive organisms. The order of the single strains tested, from most to least pressure sensitive, was Vibrio parahaemolyticus < Yersinia enterocolitica < Listeria monocytogenes < Salmonella enterica serovar Typhimurium < S. enterica serovar Enteritidis < Escherichia coli O157:H7 ≃ Staphylococcus aureus < Shigella flexneri. For each organism there existed a pressure range in which log(number of survivors) had a near linear relationship when plotted versus treatment pressure level. In this study, a decimal reduction pressure (DP) value was defined and used to measure the sensitivity of these pathogens to pressure changes. L. monocytogenes and V. parahaemolyticus were most sensitive to pressure changes, and S. flexneri was most resistant. The DP values were 16.3 MPa for L. monocytogenes, 21.7 MPa for V. parahaemolyticus, and 127.0 MPa for S. flexneri. The most pressure-resistant gram-negative bacterium, S. flexneri, and most pressure-resistant gram-positive bacterium, S. aureus, were treated at 50°C and pressures of 0.1 to 650 MPa for 10 min. High temperature considerably enhanced pressure inactivation of these two organisms and affected their sensitivities to pressure changes. The effect of treatment time on the DP values of L. monocytogenes and V. parahaemolyticus was also determined, and it was found that it did not significantly affect their DP values.

scholarly journals Potensi Ekstrak Kasar Teripang Holothuria atra, Jaeger, 1833 (Holothuroidea : Holothuriidae) Dari Pulau Panjang, Jepara

2019 ◽  
Vol 8 (3) ◽  
pp. 262-268
Author(s):  
Sonny Rieldo Damanik ◽  
Bambang Yulianto ◽  
Subagiyo Subagiyo
Keyword(s):  
Antibacterial Activity ◽  
Foodborne Pathogens ◽  
Sea Cucumber ◽  
Sampling Method ◽  
Gram Positive ◽  
Meat Extract ◽  
Gram Negative ◽  
Paper Disk ◽  
Activity Unit ◽  
Holothuria Atra

Aktivitas antibakteri yang terdapat dalam Holothuria atra dapat dimanfaatkan sebagai makanan fungsional yang dapat mengendalikan mikroflora dalam saluran pencernaan. Tujuan dari penelitian ini adalah untuk mengetahui potensi aktivitas antibakteri dari teripang H. atra terhadap bakteri B. cereus (gram positif) dan V. alginolyticus (gram negatif) sebagai foodborne pathogens. Sampel teripang H. atra diambil dari ekosistem lamun perairan Pulau Panjang dengan metode purposive sampling method untuk mengambil teripang berukuran panjang > 16 cm sebanyak 1 kg. Sampel H. atra dibersihkan lalu dipisahkan antara daging dan jeroannya, kemudian di maserasi menggunakan pelarut etil asetat dengan perbandingan 1:3 (w:v) selama 1x24 jam. Hasil maserasi diuapkan dengan rotary evaporator pada suhu 38o C. Ekstrak daging dan jeroan yang diperoleh adalah 669,8 mg dan 625,2 mg. Uji aktivitas antibakteri dilakukan dengan metode paper disk diameter 6 mm dengan konsentrasi 500 µg/disk, 1000 µg/disk, 2000 µg/disk, dan 4000 µg/disk. Aktivitas antibakteri yang diperoleh dari perbedaan konsentrasi yang diberikan berbeda secara nyata  dengan adanya peningkatan Activity Unit (AU) di setiap kenaikan konsentrasi. Aktivitas antibakteri terbesar yang diperoleh dari ekstrak daging H. atra pada konsentrasi 4000 µg/disk terhadap bakteri V. alginolyticus  (gram negatif) dan B. cereus (gram positif) masing-masing adalah 14214,08 mm2/ml dan 10508,62 mm2/ml. Aktivitas antibakteri terbesar yang diperoleh dari ekstrak jeroan H. atra pada konsentrasi  4000 µg/disk terhadap bakteri V. alginolyticus  (gram negatif) dan B. cereus (gram positif) masing-masing adalah 7858,72 mm2/ml dan 4919,68 mm2/ml. Berdasarkan penelitian ini, daging dan jeroan teripang H. atra keduanya memiliki aktivitas antibakteri terhadap bakteri B. cereus (gram positif) dan V. alginolyticus (gram negatif). The antibacterial activity contained in the bioactive compounds of sea cucumber Holothuria atra can be used as functional foods that can control microflora in the digestive tract. The purpose of this study was to determine the potential antibacterial activity of sea cucumber H. atra against B. cereus (gram positive) and V. alginolyticus (gram negative) as foodborne pathogens. The samples of H. atra in this study were taken from the seagass ecosystem of Panjang Island waters using the purposive sampling method so that the sea cucumbers taken were > 16 cm long. The obtained sea cucumber samples were cleaned and separated between the meat and the viscera, then macerated using ethyl acetate with a ration of 1:3 (w/v) for 24 hours. The solvent was evaporated using rotary evaporator at 38o C. The obtained meat and viscera extract of H. atra in this study were 669,8 mg and 625,2 mg. The antibacterial activity test was carried out using the diffusion method with a 6 mm paper disk (Kirby-Bauer Method), and the concentrations of each extract are 500 µg/disk, 1000 µg/disk, 2000 µg/disk, and 4000 µg/disk. The antibacterial activity of extracts from different concentrations were significantly different in line with the increasing results of activity unit (AU) at each increased concentration.  The largest activity unit was obtained from meat extract at a concentration of 4000 µg/disk. The antibacterial activity unit from meat extract against V. alginolyticus (gram-negative) and B. cereus (gram-positive) are 14214,08 mm2 / ml and 10508,62 mm2 / ml. The largest antibacterial activity unit of viscera extract against V. alginolyticus and B. cereus are 7858,72 mm2 / ml and 4919,68 mm2 / ml. Based on this study, meat and viscera extracts from H. atra both have antibacterial activity against B. cereus (gram-positive) and V. alginolyticus (gram-negative).

SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF NEW DERIVATIVES OF 2-OXO-2,5-DIHYDROFURANS CONTAINING AN OXOTHIAZOLIDINYLIDENE RING

2020 ◽  
Vol 54 (1 (251)) ◽  
pp. 12-16
Author(s):  
G.G. Tokmajyan ◽  
L.V. Karapetyan ◽  
R.V. Paronikyan ◽  
H.M. Stepanyan
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Shigella Flexneri ◽  
Antibacterial Activities ◽  
Gram Positive ◽  
Gram Negative ◽  
Esherichia Coli ◽  
Derivatives Of

ring were successfully synthesized based on thiosemicarbazones of 3-acetyl-2-oxo-2,5-dihydrofurans. The synthesized compounds exhibited moderate to defined antibacterial activities against Gram-positive (Staphylococcus aureus 209P and 1) and Gram-negative (Shigella Flexneri 6858, Esherichia coli 0–55) bacteria compared to furazolidone.

scholarly journals Expanding the Use of a Fluorogenic Method to Determine Activity and Mode of Action ofBacillus thuringiensisBacteriocins Against Gram-Positive and Gram-Negative Bacteria

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Norma M. de la Fuente-Salcido ◽  
J. Eleazar Barboza-Corona ◽  
A. N. Espino Monzón ◽  
R. D. Pacheco Cano ◽  
N. Balagurusamy ◽  
...  
Keyword(s):  
Shigella Flexneri ◽  
Correlation Coefficients ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Proteus Vulgaris ◽  
Gram Positive ◽  
Gram Negative ◽  
Clinically Significant ◽  
Mexican Strains ◽  
Crucial Parameter

Previously we described a rapid fluorogenic method to measure the activity of five bacteriocins produced by Mexican strains ofBacillus thuringiensisagainstB. cereus183. Here we standardize this method to efficiently determine the activity of bacteriocins against both Gram-positive and Gram-negative bacteria. It was determined that the crucial parameter required to obtain reproducible results was the number of cells used in the assay, that is,~4 × 108 cell/mL and~7 × 108 cell/mL, respectively, for target Gram-positive and Gram-negative bacteria. Comparative analyses of the fluorogenic and traditional well-diffusion assays showed correlation coefficients of 0.88 to 0.99 and 0.83 to 0.99, respectively, for Gram-positive and Gram-negative bacteria. The fluorogenic method demonstrated that the five bacteriocins ofB. thuringiensishave bacteriolytic and bacteriostatic activities against all microorganisms tested, including clinically significant bacteria such asListeria monocytogenes, Proteus vulgaris,andShigella flexnerireported previously to be resistant to the antimicrobials as determined using the well-diffusion protocol. These results demonstrate that the fluorogenic assay is a more sensitive, reliable, and rapid method when compared with the well-diffusion method and can easily be adapted in screening protocols for bacteriocin production by other microorganisms.

scholarly journals Sonodynamic Excitation of Rose Bengal for Eradication of Gram-Positive and Gram-Negative Bacteria

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Faina Nakonechny ◽  
Michael Nisnevitch ◽  
Yeshayahu Nitzan ◽  
Marina Nisnevitch
Keyword(s):  
Rose Bengal ◽  
Treatment Time ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Effective Form ◽  
Medical Instruments ◽  
First Time ◽  
The Rose ◽  
Inactivation Of Bacteria

Photodynamic antimicrobial chemotherapy based on photosensitizers activated by illumination is limited by poor penetration of visible light through skin and tissues. In order to overcome this problem, Rose Bengal was excited in the dark by 28 kHz ultrasound and was applied for inactivation of bacteria. It is demonstrated, for the first time, that the sonodynamic technique is effective for eradication of Gram-positiveStaphylococcus aureusand Gram-negativeEscherichia coli. The net sonodynamic effect was calculated as a 3-4 log10reduction in bacteria concentration, depending on the cell and the Rose Bengal concentration and the treatment time. Sonodynamic treatment may become a novel and effective form of antimicrobial therapy and can be used for low-temperature sterilization of medical instruments and surgical accessories.

scholarly journals Draft Genome Sequence of Bacillus velezensis OSY-GA1, Which Encodes Multiple Antimicrobial Metabolites and Expresses Antimicrobial Activity against Foodborne Pathogens

2019 ◽  
Vol 8 (7) ◽  
Author(s):  
Ahmed G. Abdelhamid ◽  
Walaa E. Hussein ◽  
Michelle M. Gerst ◽  
Ahmed E. Yousef
Keyword(s):  
Antimicrobial Activity ◽  
Genome Sequence ◽  
Foodborne Pathogens ◽  
Draft Genome ◽  
Soil Bacterium ◽  
Bacillus Velezensis ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Antimicrobial Metabolites

Bacillus velezensis OSY-GA1 is a Gram-positive soil bacterium that exhibits antagonistic activities against Gram-positive and Gram-negative foodborne pathogens. Here, we present the strain’s draft genome, which is 4,009,999 bp long with an average G+C content of 46.2%.

Advances in aPDT based on the combination of a porphyrinic formulation with potassium iodide: Effectiveness on bacteria and fungi planktonic/biofilm forms and viruses

2019 ◽  
Vol 23 (04n05) ◽  
pp. 534-545 ◽  
Author(s):  
Cátia Vieira ◽  
Adriele Santos ◽  
Mariana Q. Mesquita ◽  
Ana T. P. C. Gomes ◽  
M. Graça P. M. S. Neves ◽  
...  
Keyword(s):  
Treatment Time ◽  
Low Cost ◽  
Alternative Methods ◽  
Gram Positive ◽  
Gram Negative ◽  
Potentiation Effect ◽  
Low Concentrations ◽  
Form Alone ◽  
Planktonic Form ◽  
Bacteria And Fungi

The increasing world-wide rate of antibiotic resistance as well as the capacity of microorganisms to form biofilms, have led to a higher incidence of mortal infections that require alternative methods for their control. Antimicrobial photodynamic therapy (aPDT) emerged as an effective solution against resistant strains. The present work aims to evaluate the aPDT efficiency of a photosensitizer (PS) based on a low-cost formulation constituted by five cationic porphyrins (FORM) and its potentiation effect by KI on a broad spectrum of microorganisms under white light (380–700 nm, 25 W/m[Formula: see text]. The aPDT assays were performed with different concentrations of FORM (0.1 to 5.0 [Formula: see text]M) and 100 mM of KI on planktonic and biofilm forms of gram-positive (methicillin resistant Staphylococcus aureus–MRSA) and gram-negative (Escherichia coli resistant to chloramphenicol and ampicillin) bacteria, of the fungi Candida albicans and on a T4-like bacteriophage as a mammalian virus model. The results indicate that the FORM alone is an efficient PS to photoinactivate not only gram-negative and gram-positive bacteria, but also C. albicans, in planktonic and biofilm forms, and T4-like phage at low concentrations (<5.0 [Formula: see text]M). The presence of KI enhanced the photodynamic effect of this FORM for all microorganisms on the planktonic form, allowing the reduction of PS concentration and treatment time. The results also show that the combination FORM/KI is highly efficient in the elimination of already well-established biofilms of E. coli,S. aureus and C. albicans. This effect is probably associated with longer-lived iodine reactive species produced during the aPDT treatment.

scholarly journals TiO2 Application for the Photocatalytical Inactivation of S. enterica, E. coli and M. luteus Bacteria Mixtures

2020 ◽  
Vol 24 (3) ◽  
pp. 418-429
Author(s):  
Neringa Kuliesiene ◽  
Sandra Sakalauskaite ◽  
Simona Tuckute ◽  
Marius Urbonavicius ◽  
Sarunas Varnagiris ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Treatment Time ◽  
Bacterial Pathogens ◽  
Advanced Oxidation ◽  
Gram Positive ◽  
Efficient Treatment ◽  
Gram Negative ◽  
Oxidation Processes ◽  
Photocatalytic Disinfection ◽  
The Impact

AbstractWater contamination by various bacteria, viruses and other pathogens is a great threat to human health. Amongst other Advanced Oxidation Processes TiO2 photocatalysis is considered as one of the most efficient treatment for the polluted wastewater disinfection. Usually, the wastewater produced by higher risk objects, such as hospitals, implicates diverse contaminants, but efficiency of most of the Advanced Oxidation Processes is tested by using only single pathogens and information on inactivation of bacteria mixtures is still limited. In this study, photocatalytical inactivation of three commonly found bacterial pathogens (gram-positive (Micrococcus luteus) and gram-negative (Salmonella enterica, Escherichia coli)) was investigated. Efficiency of traditional photocatalytic disinfection process using single bacterial pathogens was compared to the one observed for their mixtures. The impact of photocatalytical process parameters and treatment time on bacteria disinfection efficiency was studied. Photocatalytic disinfection efficiency testing with bacteria mixtures revealed, that in the presence of TiO2 photocatalyst and UV irradiation tested gram-positive cells were inactivated slower than gram-negative cells. Another important finding was that an overall photocatalytic disinfection efficiency of bacteria mixtures is not a straight forward sum of inactivation rates of individually tested pathogens but has a strong relationship to the properties of their competitive growth.

scholarly journals Gram-negative Versus Gram-positive in Primary Pyogenic Spondylitis and Analysis of Risk Factors for Relapse

2020 ◽  
Author(s):  
Guohua Dai ◽  
Shu Zhong Li ◽  
Chuqiang Yin ◽  
Yuanliang Sun ◽  
Qizun Wang ◽  
...  
Keyword(s):  
Body Temperature ◽  
Independent Risk Factor ◽  
Treatment Time ◽  
Recurrent Infection ◽  
The Body ◽  
Negative Group ◽  
Gram Positive ◽  
Gram Negative ◽  
Positive Group ◽  
Pyogenic Spondylitis

Abstract Purpose：In the present study, we aimed to compare and analyze the clinical features, diagnosis, treatment and prognosis of primary pyogenic spondylitis caused by Gram-positive and Gram-negative bacteria.Methods: A retrospective analysis consisting of 76 cases of primary pyogenic spondylitis with complete clinical information was carried out from January 2013 to January 2020 in our hospital. The patients were divided into two groups according to Gram staining: Gram-negative group (n=33) and Gram-positive group (n=43). The clinical characteristics, diagnosis, treatment and prognosis of the two groups were compared and analyzed.Results: Staphylococcus aureus accounted for the highest proportion of the Gram-positive group, while Escherichia coli accounted for the highest proportion of the Gram-negative group. Before treatment, there were no significant differences in terms of age, gender, affected segment, spinal abscess, diabetes mellitus, course of disease, admission erythrocyte sedimentation rate (ESR), admission C-reactive protein (CRP), and admission white blood cell (WBC) count between the two groups (P>0.05). After treatment, there were no statistically significant differences in discharge ESR, discharge CRP, ESR decline rate, CRP decline rate, surgery, recurrence, follow-up time, hospital stay, and body temperature ≥38℃ between the two groups (P>0.05). The body temperature of the Gram-negative group was higher compared with the Gram-positive group, and the number of patients with urinary tract infection in the Gram-negative group was significantly greater compared with the Gram-positive group (P<0.05). Antibiotic treatment time <6 weeks was an independent risk factor for recurrent infection.Conclusions: The body temperature of the Gram-negative group was higher compared with the Gram-positive group, and there were significantly more cases with urinary tract infection in the Gram-negative group compared with the Gram-positive group (P<0.05). Antibiotic treatment time <6 weeks was an independent risk factor for recurrent infection.

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