Acid-Sensitive Enteric Pathogens Are Protected from Killing under Extremely Acidic Conditions of pH 2.5 when They Are Inoculated onto Certain Solid Food Sources

1998 ◽  
Vol 64 (10) ◽  
pp. 3882-3886 ◽  
Author(s):  
Scott R. Waterman ◽  
P. L. C. Small
Keyword(s):  
Food Source ◽  
Survival Rates ◽  
Ground Beef ◽  
Genetically Engineered ◽  
Enteric Pathogens ◽  
Food Sources ◽  
High Survival ◽  
Modes Of Transmission ◽  
Food Borne ◽  
Acidic Conditions

ABSTRACT Gastric acidity is recognized as the first line of defense against food-borne pathogens, and the ability of pathogens to resist this pH corresponds to their oral infective dose (ID). Naturally occurring and genetically engineered acid-sensitive enteric pathogens were examined for their ability to survive under acidic conditions of pH 2.5 for 2 h at 37°C when inoculated onto ground beef. Each of the strains displayed significantly high survival rates under these normally lethal conditions. The acid-sensitive pathogensCampylobacter jejuni and Vibrio cholerae, which were protected at lower levels from acid-induced killing by ground beef under these conditions, were sensitive to killing in acidified media at pH 5.0 but survived at pH 6.0. Salmonella inoculated onto the surface of preacidified ground beef could not survive if the pH on the surface of the beef was 2.61 or lower but was viable if the surface pH was 3.27. This implies that the pH of the microenvironment occupied by the bacteria on the surface of the food source is critical for their survival. Salmonella was also shown to be protected from killing when inoculated onto boiled egg white, a food source high in protein and low in fat. These results may explain whySalmonella species have a higher oral ID of approximately 105 cells when administered under defined conditions but have been observed to cause disease at doses as low as 50 to 100 organisms when consumed as part of a contaminated food source. They may also help explain why some pathogens are associated primarily with food-borne modes of transmission rather than fecal-oral transmission.

scholarly journals Room-temperature Storage of Lyophilized Engineered Bacteria using Tardigrade Intrinsically Disordered Proteins

2021 ◽  
Author(s):  
Yixian Yang ◽  
Zhandong Jiao ◽  
Shao Zhang ◽  
Mingjian Shan ◽  
Sizhe Duan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Intrinsically Disordered Proteins ◽  
Survival Rates ◽  
Genetically Engineered ◽  
Disordered Proteins ◽  
High Survival ◽  
Room Temperature Storage ◽  
Intrinsically Disordered ◽  
Engineered Bacteria ◽  
Temperature Storage

Tardigrades, which live in transiently wet environments such as moss, are well-known for their extreme resistance to desiccation. Tardigrade intrinsically disordered proteins (TDPs) have been reported to also protect bacteria and yeast under desiccation. In this study, we utilized lyophilization to achieve room-temperature storage of engineered bacteria. By using TDPs, engineered bacteria are protected under lyophilization and their original functions are preserved. This study shows that TDPs can be expressed in the Escherichia coli (E. coli) BL21 and DH5α, and bacteria treated with Cytosolic-abundant heat soluble protein (CAHS) 106094 displayed the highest survival rate after lyophilization. Moreover, this study shows that the co-expression of TDPs can improve the preservation of bacteria and maintain high survival rates after prolonged room temperature storage. Additionally, the TDPs can be expressed using different vectors, which means that they can be used in different types of engineered bacteria. This study offers a new storage method that not only improves the storage of biological material for industrial and daily usage, but also for future iGEM (International Genetically Engineered Machine Competition) teams to store and use their engineered bacteria in different applications.

scholarly journals Probiotic Properties of Bacillus Strains Isolated from Stingless Bee (Heterotrigona itama) Honey Collected across Malaysia

2019 ◽  
Vol 17 (1) ◽  
pp. 278 ◽  
Author(s):  
Fatin Aina Zulkhairi Amin ◽  
Suriana Sabri ◽  
Maznah Ismail ◽  
Kim Wei Chan ◽  
Norsharina Ismail ◽  
...  
Keyword(s):  
Survival Rates ◽  
Lactobacillus Rhamnosus ◽  
Probiotic Strain ◽  
Stingless Bee ◽  
Bacillus Species ◽  
High Survival ◽  
Probiotic Properties ◽  
Gram Staining ◽  
Significant Difference ◽  
Acidic Conditions

This study aimed to isolate, identify, and evaluate the probiotic properties of Bacillus species from honey of the stingless bee Heterotrigona itama. Bacillus spp. were isolated from five different H. itama meliponicultures, and the isolates were characterized through Gram-staining and a catalase test. Tolerance to acidic conditions and bile salt (0.3%), hydrophobicity, and autoaggregation tests were performed to assess the probiotic properties of the selected isolates, B. amyloliquefaciens HTI-19 and B. subtilis HTI-23. Both Bacillus isolates exhibited excellent antimicrobial activity against both Gram-positive and Gram-negative bacteria and possessed significantly high survival rates in 0.3% bile solution for 3 h. Their survival rates in acidic conditions were also comparable to a commercial probiotic strain, Lactobacillus rhamnosus GG. Interestingly, the hydrophobicity and autoaggregation percentage showed no significant difference from L. rhamnosus GG, a commercial probiotic strain. The results from this study suggest that B. amyloliquefaciens HTI-19 and B. subtilis HTI-23 isolated from stingless bee honey have considerably good probiotic properties. Therefore, more studies should be done to investigate the effects of these bacteria cultures on gastrointestinal health.

scholarly journals In Silico Characterization of Toxin-Antitoxin Systems in Campylobacter Isolates Recovered from Food Sources and Sporadic Human Illness

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 72
Author(s):  
Bishoy Wadie ◽  
Mohamed A. Abdel-Fattah ◽  
Alshymaa Yousef ◽  
Shaimaa F. Mouftah ◽  
Mohamed Elhadidy ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
In Silico ◽  
Antimicrobial Agents ◽  
Food Sources ◽  
Model Organisms ◽  
Food Borne ◽  
Food Borne Illness ◽  
Human Illness ◽  
Clonal Population Structure ◽  
In Silico Characterization

Campylobacter spp. represents the most common cause of gastroenteritis worldwide with the potential to cause serious sequelae. The ability of Campylobacter to survive stressful environmental conditions has been directly linked with food-borne illness. Toxin-antitoxin (TA) modules play an important role as defense systems against antimicrobial agents and are considered an invaluable strategy harnessed by bacterial pathogens to survive in stressful environments. Although TA modules have been extensively studied in model organisms such as Escherichia coli K12, the TA landscape in Campylobacter remains largely unexplored. Therefore, in this study, a comprehensive in silico screen of 111 Campylobacter (90 C.jejuni and 21 C.coli) isolates recovered from different food and clinical sources was performed. We identified 10 type II TA systems belonging to four TA families predicted in Campylobacter genomes. Furthermore, there was a significant association between the clonal population structure and distribution of TA modules; more specifically, most (12/13) of the Campylobacter isolates belonging to ST-21 isolates possess HicB-HicA TA modules. Finally, we observed a high degree of shared synteny among isolates bearing certain TA systems or even coexisting pairs of TA systems. Collectively, these findings provide useful insights about the distribution of TA modules in a heterogeneous pool of Campylobacter isolates from different sources, thus developing a better understanding regarding the mechanisms by which these pathogens survive stressful environmental conditions, which will further aid in the future designing of more targeted antimicrobials.

scholarly journals Cognitive decline in patients with prostate cancer: study protocol of a prospective cohort, NEON-PC

BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e043844
Author(s):  
Natalia Araujo ◽  
Samantha Morais ◽  
Ana Rute Costa ◽  
Raquel Braga ◽  
Ana Filipa Carneiro ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cognitive Decline ◽  
Cognitive Performance ◽  
Androgen Deprivation Therapy ◽  
Survival Rates ◽  
Cardiovascular Complications ◽  
Androgen Deprivation ◽  
High Survival ◽  
The Impact

IntroductionProstate cancer is the most prevalent oncological disease among men in industrialised countries. Despite the high survival rates, treatments are often associated with adverse effects, including metabolic and cardiovascular complications, sexual dysfunction and, to a lesser extent, cognitive decline. This study was primarily designed to evaluate the trajectories of cognitive performance in patients with prostate cancer, and to quantify the impact of the disease and its treatments on the occurrence of cognitive decline.MethodsParticipants will be recruited from two main hospitals providing care to approximately half of the patients with prostate cancer in Northern Portugal (Portuguese Institute of Oncology of Porto and São João Hospital Centre), and will comprise a cohort of recently diagnosed patients with prostate cancer proposed for different treatment plans, including: (1) radical prostatectomy; (2) brachytherapy and/or radiotherapy; (3) radiotherapy in combination with androgen deprivation therapy and (4) androgen deprivation therapy (with or without chemotherapy). Recruitment began in February 2018 and is expected to continue until the first semester of 2021. Follow-up evaluations will be conducted at 1, 3, 5, 7 and 10 years. Sociodemographic, behavioural and clinical characteristics, anxiety and depression, health literacy, health status, quality of life, and sleep quality will be assessed. Blood pressure and anthropometrics will be measured, and a fasting blood sample will be collected. Participants’ cognitive performance will be evaluated before treatments and throughout follow-up (Montreal Cognitive Assessment and Cube Test as well as Brain on Track for remote monitoring). All participants suspected of cognitive impairment will undergo neuropsychological tests and clinical observation by a neurologist.Ethics and disseminationThe study was approved by the Ethics Committee of the hospitals involved. All participants will provide written informed consent, and study procedures will be developed to ensure data protection and confidentiality. Results will be disseminated through publication in peer-reviewed journals and presentation in scientific meetings.

scholarly journals Bone marrow niche crosses paths with BMPs: a road to protection and persistence in CML

2019 ◽  
Vol 47 (5) ◽  
pp. 1307-1325 ◽  
Author(s):  
Caroline Busch ◽  
Helen Wheadon
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Bone Morphogenetic Proteins ◽  
Kinase Inhibitor ◽  
Survival Rates ◽  
High Survival ◽  
Bone Marrow Niche ◽  
Matrix Deposition ◽  
Bmp Receptors ◽  
Number Of Patients

Abstract Chronic myeloid leukaemia (CML) is a paradigm of precision medicine, being one of the first cancers to be treated with targeted therapy. This has revolutionised CML therapy and patient outcome, with high survival rates. However, this now means an ever-increasing number of patients are living with the disease on life-long tyrosine kinase inhibitor (TKI) therapy, with most patients anticipated to have near normal life expectancy. Unfortunately, in a significant number of patients, TKIs are not curative. This low-level disease persistence suggests that despite a molecularly targeted therapeutic approach, there are BCR-ABL1-independent mechanisms exploited to sustain the survival of a small cell population of leukaemic stem cells (LSCs). In CML, LSCs display many features akin to haemopoietic stem cells, namely quiescence, self-renewal and the ability to produce mature progeny, this all occurs through intrinsic and extrinsic signals within the specialised microenvironment of the bone marrow (BM) niche. One important avenue of investigation in CML is how the disease highjacks the BM, thereby remodelling this microenvironment to create a niche, which enables LSC persistence and resistance to TKI treatment. In this review, we explore how changes in growth factor levels, in particular, the bone morphogenetic proteins (BMPs) and pro-inflammatory cytokines, impact on cell behaviour, extracellular matrix deposition and bone remodelling in CML. We also discuss the challenges in targeting LSCs and the potential of dual targeting using combination therapies against BMP receptors and BCR-ABL1.

scholarly journals Survival Rate of 1008 Short Dental Implants with 21 Months of Average Follow-Up: A Retrospective Study

2020 ◽  
Vol 9 (12) ◽  
pp. 3943
Author(s):  
João Caramês ◽  
Ana Catarina Pinto ◽  
Gonçalo Caramês ◽  
Helena Francisco ◽  
Joana Fialho ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Survival Rate ◽  
Dental Implants ◽  
Cox Regression ◽  
Survival Rates ◽  
High Survival ◽  
Implant Survival ◽  
Posterior Maxilla ◽  
Clinical Records

This retrospective study evaluated the survival rate of short, sandblasted acid-etched surfaced implants with 6 and 8 mm lengths with at least 120 days of follow-up. Data concerning patient, implant and surgery characteristics were retrieved from clinical records. Sandblasted and acid-etched (SLA)-surfaced tissue-level 6 mm (TL6) or 8 mm (TL8) implants or bone-level tapered 8 mm (BLT8) implants were used. Absolute and relative frequency distributions were calculated for qualitative variables and mean values and standard deviations for quantitative variables. A Cox regression model was performed to verify whether type, length and/or width influence the implant survival. The cumulative implant survival rate was assessed by time-to-event analyses (Kaplan–Meier estimator). In all, 513 patients with a mean age of 58.00 ± 12.44 years received 1008 dental implants with a mean follow-up of 21.57 ± 10.77 months. Most implants (78.17%) presented a 4.1 mm diameter, and the most frequent indication was a partially edentulous arch (44.15%). The most frequent locations were the posterior mandible (53.97%) and the posterior maxilla (31.55%). No significant differences were found in survival rates between groups of type, length and width of implant with the cumulative rate being 97.7% ± 0.5%. Within the limitations of this study, the evaluated short implants are a predictable option with high survival rates during the follow-up without statistical differences between the appraised types, lengths and widths.

Overstory treatment and planting season affect survival of replacement tree species in emerald ash borer threatened Fraxinus nigra forests in Minnesota, USA

2015 ◽  
Vol 45 (12) ◽  
pp. 1728-1738 ◽  
Author(s):  
Christopher E. Looney ◽  
Anthony W. D’Amato ◽  
Brian J. Palik ◽  
Robert A. Slesak
Keyword(s):  
Tree Species ◽  
Group Selection ◽  
Survival Rates ◽  
Emerald Ash Borer ◽  
Species Selection ◽  
Ecosystem Functions ◽  
Control Group ◽  
High Survival ◽  
Fraxinus Nigra ◽  
Black Ash

Fraxinus nigra Marsh. (black ash) wetland forests in northern Minnesota, USA, are threatened by the invasive insect, emerald ash borer (Agrilus planipennis Fairmaire (EAB)). A potential management option is promoting regeneration of tree species that are not EAB hosts to maintain ecosystem functions. Using an operational-scale field experiment, we examined the survival of 12 alternative tree species in response to different canopy treatments. We planted the seedlings in 1.6 ha plots assigned to four replicated canopy treatments: untreated control, group selection (0.04 ha gaps, 20% of stand), black ash girdling to emulate EAB-induced mortality, and clearcut. Fall and spring plantings were used to compare the effects of spring ponding. Control (32.9%), group selection (34.5%), and girdling (33.3%) treatments had comparable overall seedling survival. Survival in the clear-cut treatments was significantly lower (22%). Species selection, overstory treatment, and season of planting together resulted in survival rates ranging from 0.08% to 94.1%. Conifer species had low overall rates of survival (10.7%), whereas some species with native ranges not presently overlapping with northern F. nigra forests, e.g., Quercus bicolor Willd. (75.5%), had high survival rates. If growth is light-limited, group selection may be effective in promoting recruitment and supporting a larger variety of species.

RED JUNGLE FOWL HAVE MORE CONTRAFREELOADING THAN WHITE LEGHORN LAYERS: EFFECT OF FOOD DEPRIVATION AND CONSEQUENCES FOR INFORMATION GAIN

Behaviour ◽  
2002 ◽  
Vol 139 (9) ◽  
pp. 1195-1209 ◽  
Author(s):  
Per Jensen ◽  
Karin Schütz ◽  
Christina Lindqvist
Keyword(s):  
Food Deprivation ◽  
Food Source ◽  
Information Gain ◽  
High Gain ◽  
Alternative Food ◽  
Food Sources ◽  
Production Environment ◽  
White Leghorn ◽  
Wood Shavings ◽  
Red Jungle Fowl

AbstractContrafreeloading (CFL), i.e. choosing food which requires work over free food, occurs at a higher rate in red jungle fowl (Gallus gallus) compared to White Leghorn layers. We examined whether this difference between breeds was altered by food deprivation and whether it affected the information gained about alternative food sources. In a first experiment, twenty birds of each breed were deprived for zero, three and six hours and then allowed a choice of feeding from freely available food or food mixed with wood shavings. In both breeds, CFL tended to decrease after deprivation, but jungle fowl consistently showed more CFL than Leghorns also after food deprivation. This shows that differences in CFL between breeds were not altered by food deprivation, and the larger CFL in jungle fowl may represent a genetically based difference in feeding strategy. In a second experiment, we examined whether the differences in CFL affected how the birds acquired information about alternative food sites of different quality. Twenty birds of each breed were allowed to forage during three 10 min sessions in a four armed maze, where symbols in each end of the arms indicated the location of four different quality food sources; 'high gain' (freely available food), 'medium gain' (70% food, 30% wood shavings), 'low gain' (30% food), and 'no gain' (100% wood shavings). Each bird was then tested in the same maze when the 'high gain' food source and its symbol had been removed, and the other three sources contained only the symbols and wood shavings. Jungle fowl chose the symbol indicating the best available food source significantly more often than the Leghorns. The results indicate that Leghorn gain less information during foraging, which may have consequences for their adaptation capacity in a production environment. This could either be a consequence of Leghorns showing less CFL, or a generally impaired learning capacity of Leghorns compared to jungle fowl.

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