Survival of Listeria monocytogenes Strain H7762 and Resistance to Simulated Gastric Fluid following Exposure to Frankfurter Exudate†

2004 ◽  
Vol 67 (6) ◽  
pp. 1170-1176 ◽  
Author(s):  
LAURA D. WONDERLING ◽  
DARRELL O. BAYLES
Keyword(s):  
Listeria Monocytogenes ◽  
Brain Heart Infusion ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Time Of Death ◽  
Nonlinear Regression Analysis ◽  
Underlying Distribution ◽  
Acid Sensitivity ◽  
The Mean ◽  
Mean Time

Listeria monocytogenes strain H7762, a frankfurter isolate, was tested to determine whether it was able to survive at 4°C in frankfurter pack fluid (exudate) and to determine whether food exposure affects its acid sensitivity. Cultures were sampled and tested for acid sensitivity by challenge with simulated gastric fluid (SGF). SGF challenges performed immediately after inoculation revealed that between 20 and 26% of the cells survived the full 30 min of SGF challenge regardless of whether the cells were inoculated into brain heart infusion broth (BHI) or exudate. After 2 days of incubation, cells exposed to both exudate and BHI had significantly decreased SGF resistance; however, the cells exposed to exudate were significantly more SGF resistant than cells exposed to BHI (after 15 min of SGF treatment, 33% of the exudate-exposed cells survived and 12% of the BHI-exposed cells survived). L. monocytogenes exposed to exudate had greater SGF resistance at all challenge times compared with BHI-exposed cells from day 2 through day 4. From days 8 to 15, exudate-exposed cells continued to have greater SGF resistance than BHI-exposed cells up to 10 min of SGF challenge but were as sensitive as the BHI-exposed cells at 20 to 30 min of challenge. By day 25, cells exposed to exudate were significantly more sensitive to SGF challenge than BHI-exposed cells. The survivor data generated from SGF challenges were modeled by a nonlinear regression analysis to calculate the underlying distribution of SGF resistance found in the challenged populations. These analyses indicated that L. monocytogenes exposed to exudate at 48C had a broader distribution of resistance to SGF compared with cells exposed to BHI at 4°C. In addition, the mean time of death during SGF treatment was greater after exposure to exudate, indicating that cells exposed to exudate were more resistant to killing by SGF. These data suggest that exposure to frankfurter exudate might render L. monocytogenes more able to survive the stomach environment during the initial stages of infection.

scholarly journals TREATMENT OF VIBRIOSIS DISEASE (Vibrio harveyi) IN VANAME SHRIMP (Litopenaeus vannamei, Boone 1931) USING Avicennia alba LEAVES EXTRACT

2019 ◽  
Vol 7 (2) ◽  
pp. 909
Author(s):  
Dian Rusadi ◽  
Wardiyanto Wardiyanto ◽  
Rara Diantari
Keyword(s):  
Survival Rate ◽  
Clinical Symptoms ◽  
Vibrio Harveyi ◽  
Time Of Death ◽  
Mangrove Plant ◽  
Vibrio Infection ◽  
The Mean ◽  
Avicennia Alba ◽  
Mean Time ◽  
Better Than

Avicennia alba is a mangrove plant that often ued by coastal society as a traditional medecine, it is potential to be dveloped as the sources of pharmaceutical. The aim of the research is to examine the effect of Avicennia alba leaves extract various concentrations to Vibrio harveyi infection on vaname shrimp. The addition of the extract is thought to be used as an antibacterial so that it can give effect to the attack of V. harveyi in vaname shrimp. Vaname shrimps (total of 120 shrimps) with a weight of 10±2g/ind were injected intramuscularly with V. harveyi bacteria in 107 CFU/ml density. After the occurrences of clinical symptoms, the shrimps were immersed into A. alba leaves extract with concentration 0 ppm, 150 ppm, 250 ppm, and 350 ppm for 21 days. The results showed that the addition leaves extract can increase shrimp’s survival rate as much as 46.67% and increase the shrimp’s ability to prevent (RPS) V. harveyi infection untill of 70±15%. The mean time of death (MTD) was 106±18.33 hours, it caused there ar active compounds contained such as saponin, tannin, and steroid be suspected antibacterial so that they can protect shrimp from the effect of Vibrio infection damage. Giving a concentration of 250 ppm Avicennia alba leaves extract can treat vaname shrimp which was attacked by V. harveyi better than other treatments.

Effect of Acid Adaptation on Growth during Storage at 10°C and Resistance to Simulated Gastric Fluid of Listeria monocytogenes Inoculated onto Bologna Formulated with or without Antimicrobials

2007 ◽  
Vol 70 (1) ◽  
pp. 65-69 ◽  
Author(s):  
GIOVANNI FORMATO ◽  
IFIGENIA GEORNARAS ◽  
IOANNA M. BARMPALIA ◽  
PANAGIOTIS N. SKANDAMIS ◽  
KEITH E. BELK ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Acid Adaptation ◽  
Treatment Groups ◽  
Cell Numbers ◽  
Product Formulation ◽  
Inhibition Of Growth ◽  
Control Samples

The fate of acid-adapted and nonadapted Listeria monocytogenes inoculated onto bologna slices (formulated with or without antimicrobials) was examined during storage and after exposure to in vitro gastric challenge. Bologna slices formulated with no antimicrobials (control), 3% sodium lactate (SL), or 1.8% SL plus 0.25% sodium diacetate (SD) were inoculated (2 log CFU/cm2) with a 10-strain composite of acid-adapted or nonadapted L. monocytogenes strains. Growth or survival of the two inocula on bologna was evaluated during vacuum-packaged storage (10°C) for up to 36 days. Survival of previously acid-adapted or nonadapted L. monocytogenes on stored bologna exposed to simulated gastric fluid (adjusted to pH 1.0 with HCl) for 20, 40, and 60 min also was determined. As expected, inclusion of antimicrobials in the product formulation inhibited growth of L. monocytogenes during storage of vacuum-packaged bologna compared with growth on control samples. Acid adaptation of L. monocytogenes prior to product inoculation did not affect subsequent survival or growth on bologna or resistance to simulated gastric fluid (P > 0.05). Survival of L. monocytogenes exposed to simulated gastric fluid during storage increased with product age, growth phase of the cells, and possibly age of the cells, particularly for control samples (no antimicrobials), in which the pathogen grew uninhibited to approximately 6 log CFU/cm2 by day 8 of storage. Inhibition of L. monocytogenes growth on product formulated with antimicrobials was associated with only sporadic and small numbers of survivors following exposure of these samples to simulated gastric fluid, especially in samples stored longer. However, cell numbers in these treatment groups before the gastric challenge did not exceed 3.8 log CFU/cm2. Inhibition of growth on product with antimicrobials precluded detection of survivors resistant to the effects of simulated gastric fluid.

scholarly journals Listeria monocytogenes Strains Underrepresented during Selective Enrichment with an ISO Method Might Dominate during Passage through Simulated Gastric Fluid andIn VitroInfection of Caco-2 Cells

2016 ◽  
Vol 82 (23) ◽  
pp. 6846-6858 ◽  
Author(s):  
Evangelia Zilelidou ◽  
Christina-Vasiliki Karmiri ◽  
Georgia Zoumpopoulou ◽  
Eleni Mavrogonatou ◽  
Dimitris Kletsas ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Simultaneous Exposure ◽  
Relative Population ◽  
Content Type ◽  
Selective Enrichment ◽  
Outbreak Investigations ◽  
Multiple Strains

ABSTRACTVariousListeria monocytogenesstrains may contaminate a single food product, potentially resulting in simultaneous exposure of consumers to multiple strains. However, due to bias in strain recovery,L. monocytogenesstrains isolated from foods by selective enrichment (SE) might not always represent those that can better survive the immune system of a patient. We investigated the effect of cocultivation in tryptic soy broth with 0.6% yeast extract (TSB-Y) at 10°C for 8 days on (i) the detection ofL. monocytogenesstrains during SE with the ISO 11290-1:1996/Amd 1:2004 protocol and (ii) thein vitrovirulence of strains toward the Caco-2 human colon epithelial cancer cell line following exposure to simulated gastric fluid (SGF; pH 2.0)-HCl (37°C). We determined whether the strains which were favored by SE would be effective competitors under the conditions of challenges related to gastrointestinal passage of the pathogen. Interstrain competition ofL. monocytogenesin TSB-Y determined the relative population of each strain at the beginning of SE. This in turn impacted the outcome of SE (i.e., favoring survival of competitors with better fitness) and the levels exposed subsequently to SGF. However, strong growth competitors could be outcompeted after SGF exposure and infection of Caco-2 cells by strains outgrown in TSB-Y and underdetected (or even missed) during enrichment. Our data demonstrate a preferential selection of certainL. monocytogenesstrains during enrichments, often not reflecting a selective advantage of strains during infection. These findings highlight a noteworthy scenario associated with the difficulty of matching the source of infection (food) with theL. monocytogenesisolate appearing to be the causative agent during listeriosis outbreak investigations.IMPORTANCEThis report is relevant to understanding the processes involved in selection and prevalence of certainL. monocytogenesstrains in different environments (i.e., foods or sites of humans exposed to the pathogen). It highlights the occurrence of multiple strains in the same food as an important aspect contributing to mismatches between clinical isolates and infection sources during listeriosis outbreak investigations.

Resistance of Listeria monocytogenes F2365 Cells to Synthetic Gastric Fluid Is Greater following Growth on Ready-to-Eat Deli Turkey Meat Than in Brain Heart Infusion Broth

2007 ◽  
Vol 70 (11) ◽  
pp. 2589-2595 ◽  
Author(s):  
LUKE D. PETERSON ◽  
NANCY G. FAITH ◽  
CHARLES J. CZUPRYNSKI
Keyword(s):  
Listeria Monocytogenes ◽  
Gastrointestinal Tract ◽  
High Risk ◽  
Stationary Phase ◽  
Brain Heart Infusion ◽  
Gastric Fluid ◽  
Brain Heart Infusion Broth ◽  
Early Stationary Phase ◽  
Turkey Meat ◽  
Enhanced Resistance

Ready-to-eat (RTE) deli meats have been categorized as high-risk foods for contraction of foodborne listeriosis. Several recent listeriosis outbreaks have been associated with the consumption of RTE deli turkey meat. In this study, we examined whether the growth of Listeria monocytogenes F2365 on commercially prepared RTE deli turkey meat causes listerial cells to become more resistant to inactivation by synthetic gastric fluid (SGF). Listerial cells grown on turkey meat to late logarithmic–early stationary phase were significantly more resistant to SGF at pH 7.0, 5.0, or 3.5 than listerial cells grown in brain heart infusion (BHI) broth. The pH was lower in the fluid in packages of turkey meat than in BHI broth (6.5 versus 7.5). However, listerial cells grown in BHI broth adjusted to a lower pH (6.0) did not exhibit enhanced resistance to SGF. The lesser resistance to SGF of listerial cells grown in BHI broth may be due, in part, to the presence of glucose (0.2%). This study indicates the environment presented by the growth of L. monocytogenes on deli turkey meat affects its ability to survive conditions it encounters in the gastrointestinal tract.

scholarly journals Listeria monocytogenes Grown at 7°C Shows Reduced Acid Survival and an Altered Transcriptional Response to Acid Shock Compared to L. monocytogenes Grown at 37°C

2012 ◽  
Vol 78 (11) ◽  
pp. 3824-3836 ◽  
Author(s):  
R. A. Ivy ◽  
M. Wiedmann ◽  
K. J. Boor
Keyword(s):  
Listeria Monocytogenes ◽  
Stationary Phase ◽  
Growth Phase ◽  
Transcriptional Response ◽  
Brain Heart Infusion ◽  
Gastric Fluid ◽  
Food Storage ◽  
Content Type ◽  
Acid Shock ◽  
Temperature And Growth

ABSTRACTSurvival of the food-borne pathogenListeria monocytogenesin acidic environments (e.g., in the human stomach) is vital to its transmission. Refrigerated, ready-to-eat foods have been sources of listeriosis outbreaks. The purpose of this study was to determine whether growth at a low temperature (i.e., 7°C) affectsL. monocytogenessurvival or gene transcription after exposure to a simulated gastric environment (i.e., acid shock at 37°C).L. monocytogenescells grown at 7°C were less resistant to artificial gastric fluid (AGF) or acidified brain heart infusion broth (ABHI) than bacteria grown at higher temperatures (i.e., 30°C or 37°C). ForL. monocytogenesgrown at 7°C, stationary-phase cells were more resistant to ABHI than log-phase cells, indicating that both temperature and growth phase affect acid survival. Microarray transcriptomic analysis revealed that the number and functional categories of genes differentially expressed after acid shock differed according to both growth temperature and growth phase. The acid response ofL. monocytogenesgrown to log phase at 37°C involved stress-related transcriptional regulators (i.e., σB, σH, CtsR, and HrcA), some of which have been implicated in adaptation to the intracellular environment. In contrast, for bacteria grown at 7°C to stationary phase, acid exposure did not result in differential expression of the stress regulons examined. However, two large operons encoding bacteriophage-like proteins were induced, suggesting lysogenic prophage induction. The adaptive transcriptional response observed in 37°C-grown cells was largely absent in 7°C-grown cells, suggesting that temperatures commonly encountered during food storage and distribution affect the ability ofL. monocytogenesto survive gastric passage and ultimately cause disease.

Feline Melanoma: A Comparative Study of Ocular, Oral, and Dermal Neoplasms

1988 ◽  
Vol 25 (2) ◽  
pp. 105-112 ◽  
Author(s):  
A. K. Patnaik ◽  
S. Mooney
Keyword(s):  
Comparative Study ◽  
Cutaneous Melanoma ◽  
Ciliary Body ◽  
Spindle Cell ◽  
Time Of Death ◽  
Oral Melanoma ◽  
Intraocular Tumors ◽  
The Mean ◽  
Mean Time

Melanomas diagnosed in 29 cats over an 11 year period included 19 ocular (16 intraocular, three palpebral), five oral, and five dermal melanomas. Intraocular melanomas involved the ciliary body and iris in 12; the whole eye was involved in four. The average age of cats with intraocular melanomas was 11 years; the female:male ratio was 9:7. Histologically, eight intraocular tumors were mixed, six were epithelioid, and two were spindle cell. Ten of 16 cats (62.5%) with intraocular melanomas were killed because of the tumor at a mean of 156 days; four arc living with no evidence of disease (average, 255 days). The mean time of death in cats with palpebral melanoma was 409 days. Metastasis occurred in 63% of cats with intraocular melanoma and all cats with palpebral melanoma. Four cats with oral melanoma were killed at a mean of 61 days; all had metastasis. Of five cats with cutaneous melanoma, one was killed with metastasis at 90 days; three cats were alive without evidence of recurrence or metastasis >365 days after surgery. Results of this study indicate that in the cat, ocular melanomas are more common than oral and dermal melanomas, and ocular and oral melanomas arc more malignant than dermal melanomas, with higher rates of mortality and metastasis.

scholarly journals Metarhizium brunneum Petch Fungi is Effective as a Bioinsecticide Against Coptotermes curvignathus Holmgren Termite Pests in the Laboratory

Elkawnie ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 259
Author(s):  
Muhammad Sayuthi ◽  
Teguh Santoso ◽  
Iswadi Iswadi
Keyword(s):  
Economic Value ◽  
Observation Time ◽  
Distilled Water ◽  
Time Of Death ◽  
Randomized Design ◽  
The Mean ◽  
Completely Randomized Design ◽  
And Control ◽  
Mean Time ◽  
Density Treatment

Abstract: Nutmeg is a plantation crop and has high economic value. Currently, the cultivation of nutmeg is experiencing many obstacles. One of them is termite pests. So far, the control is carried out using chemical insecticides and hurts the environment. Therefore it is necessary to control other environmentally friendly ways, and one of them is by using the fungi M. brunneum as an ecologically friendly bioinsecticide. The purpose of this study was to analyze the effectiveness of M. brunneum as a bioinsecticide against the termite C. curvignathus as an essential pest in nutmeg plantations. This research using a completely randomized design (CRD). The results showed that the mean percentage viability of M. brunneum conidia at each observation time was classified as useful. The germination of conidia increased to 89.78 % after 72 hours of observation. Conidia density 103/ mL distilled water. The highest mortality rate of C. curvignathus was found at a density of 1010 conidia/ mL of distilled water. The mean time of death for C. curvignathus after application of conidia density treatment of 1010/ mL of distilled water was 2.15 days and the death of C. curvignathus was 3.35 days using conidia density treatment 103/ mL of distilled water. 1 day after application reaches 33.20 % and increases to observation at 5 days after application reaches 100 %. The highest food inhibition occurred in treatment 1010/ mL distilled water (65.81 %) which was significantly different from treatment 105/ mL distilled water (43.23 %), and 103/ mL distilled water (41.61 %) and control (0.00).Abstrak: Pala merupakan tanaman perkebunan dan bernilai ekonomi tinggi. Pada saat ini budidayanya mengalami banyak hambatan. Satu diantaranya adalah serangan hama rayap. Selama ini  pengendalian hama rayap dilakukan dengan menggunakan insektisida kimia dan berpengaruh negatif terhadap lingkungan. Oleh karenanya perlu pengendalian cara lain yang ramah lingkungan dan satu diantaranya dengan menggunakan cendawan M. brunneum sebagai bioinsektisida yang ramah lingkungan. Tujuan dari penelitian ini adalah menganalisis efektivitas M. brunneum sebagai bioinsektisida terhadap hama rayap C. curvignathus. Penelitian ini dilaksanakan di Laboratorium Hama Tanaman dan Laboratorium Dasar Proteksi Tanaman Program Studi Proteksi Tanaman Fakultas Pertanian Universitas Syiah Kuala, sejak bulan Februari hingga September 2018, dengan menggunakan Rancangan Acak Lengkap (RAL). Hasil penelitian menunjukkan bahwa persentase viabilitas rata-rata dari konidia M. brunneum pada setiap waktu pengamatan tergolong efektif. Perkecambahan konidia semakin meningkat hingga mencapai 89,78 % setelah diamati pada jam yang ke 72. Rata-rata waktu kematian rayap C. curvignathus setelah aplikasi perlakuan kerapatan konidia 1010/ mL akuades adalah 2,15 hari dan terjadi kematian rayap C. curvignathus 3.35 hari dengan menggunakan perlakuan kerapatan konidia 103/ mL akuades. Rata-rata mortalitas tertinggi rayap C. curvignathus ditemukan pada perlakuan kerapatan konidia 1010/mL aquades. 1 HSA mencapai 33,20% dan meningkat hingga pengamatan pada 5 HSA mencapai 100%. Daya hambat makan tertinggi terjadi pada perlakuan 1010/ mL aquades (65,81%) yang berbeda nyata dengan perlakuan 105/mL aquades (43,23%) dan 103/ mL aquades (41,61%) serta kontrol (0,00%).

scholarly journals Recovery of yeast from vented blood culture bottles

1975 ◽  
Vol 2 (1) ◽  
pp. 18-20
Author(s):  
G D Roberts ◽  
C Horstmeier ◽  
M Hall ◽  
J A Washington
Keyword(s):  
Blood Culture ◽  
Clinical Studies ◽  
Brain Heart Infusion ◽  
Blood Cultures ◽  
Time Interval ◽  
Time Intervals ◽  
The Mean ◽  
Mean Time ◽  
Brain Heart Infusion Medium

Rates of isolation of yeasts from blood cultures were significantly enhanced by venting vacuum blood culture bottles in studies of both stimulated and patients' blood cultures; however, the time interval to detection of positivity of yeasts in the clinical studies was significantly (P less than 0.01) shorter in a vented bottle with biphasic brain heart infusion medium than in a vented bottle with soybean-casein digest broth. The mean time intervals to detection of positivity were 2.6 days in the former and 5.2 days in the latter.

Sign in / Sign up

Export Citation Format

Share Document