Survival of Salmonella dublin and Salmonella typhimurium in Lebanon Bologna

1975 ◽  
Vol 38 (3) ◽  
pp. 150-154 ◽  
Author(s):  
J. L. SMITH ◽  
S. A. PALUMBO ◽  
J. C. KISSINGER ◽  
C. N. HUHTANEN
Keyword(s):  
Salmonella Typhimurium ◽  
Starter Culture ◽  
Viable Cell ◽  
Salmonella Dublin ◽  
Aging Period ◽  
Cell Counts ◽  
Natural Flora

Survival and destruction of Salmonella dublin and S. typhimurium added to Lebanon bologna was studied during manufacture of this sausage. During the aging period of salted cubed beef at 5 C, viable cell counts of S. dublin did not change over a 10-day period. Cell counts of S. Dublin were reduced 3 to 4 log cycles during the 4-day fermentation at 35 C; further reduction in the viable Salmonella count occurred during mellowing of the bolognas at 5 C. The number of S. typhimurium was usually reduced to an undetectible level before the end of the fermentation. Salmonella typhimurium was consistently more sensitive to the acid conditions of Lebanon bologna than was S. dublin. Introduction of an optional cooking step indicated that heating of bolognas to 51.7 C or above led to destruction of salmonellae. Unaged beef which was not inoculated with starter culture did not ferment and there was very little reduction in numbers of added salmonellae. Salmonellae were destroyed more rapidly in Lebanon bologna made from unaged beef with starter culture than in bologna made from aged beef (natural flora fermentation). Smoking also appeared to contribute to destruction of salmonellae. Four commercial Lebanon bolognas were tested for the presence of salmonellae but none were detected.

scholarly journals The impact of different commercial probiotic cultures with starters on technological, physicochemical and sensorial properties of a traditional yogurt-based appetizer “Cacık”

2019 ◽  
Vol 69 (3) ◽  
pp. 193-205
Author(s):  
Seda Altuntas ◽  
Mihriban Korukluoglu
Keyword(s):  
Bifidobacterium Longum ◽  
Starter Culture ◽  
Lactobacillus Rhamnosus ◽  
Storage Period ◽  
Viable Cell ◽  
Probiotic Bacteria ◽  
Fermentation Time ◽  
Cell Counts ◽  
Sensorial Attributes ◽  
The Impact

The selection of proper probiotic culture is essential for maintaining adequate numbers of viable cells until consumption since potential adverse interaction between selected strain and starter culture. This study examined the suitability of Cacık as a potential probiotic carrier including Lactobacillus acidophilus 74-2, Lactobacillus rhamnosus Howaru HN001TM and Bifidobacterium longum BB536 in different combinations. The presence of three probiotic strains caused higher post acidification and shorter fermentation time associated to higher counts of L. bulgaricus. Except for certain combinations containing B. longum BB536, the counts of individual probiotic bacteria were higher than 6 log g-1 for all probiotic supplemented Cacık samples. Results showed that bacterial interaction was decisive for survival over 21 days of storage. Probiotic products containing only B. longum BB536 or B. longum BB536 with L. acidophilus 74-2 did not accomplish in terms of the technological point, since the viable cell counts decerased for 2.45 log and 1.95 log per g, respecitevly, throughout the storage period. In three of totally four combinations included L. rhamnosus Howaru HN001TM alone or combined with other probiotic bacteria, the viable cell counts of L. rhamnosus Howaru HN001TM remained at the inoculated level, while the counts significantly increased in co-culture with L. acidophilus 74-2. Considering the overall sensorial attributes and survival of probiotics, Cacık supplemented with L. rhamnosus Howaru HN001TM alone, combinations of B. longum BB536 and L. rhamnosus Howaru HN001TM or L. acidophilus 74-2 and L. rhamnosus Howaru HN001TM or by all of the three tested probiotics, were suggested as suitable for further production.

scholarly journals Fermented Cranberry Fortified Buckwheat Product—Phenolic Composition, Antioxidant and Microbiological Properties

2021 ◽  
Vol 11 (19) ◽  
pp. 9241
Author(s):  
Anna Mikulajová ◽  
Zuzana Matejčeková ◽  
Silvia Mošovská ◽  
Zlatica Kohajdová ◽  
Ľubomír Valík ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Positive Impact ◽  
Starter Culture ◽  
Lactobacillus Rhamnosus ◽  
Storage Period ◽  
Probiotic Strain ◽  
Experimental Period ◽  
Viable Cell ◽  
Total Phenolic ◽  
Cell Counts

This study determined the effect of fermentation by Fresco DVS 1010 starter culture with added probiotic strain Lactobacillus rhamnosus GG and potentially probiotic isolate Lactobacillus plantarum HM1, at fermentation times (0, 8 h) and cold storage period (24 h, 4th day, 7th day, 14th day), on microbial parameters, pH changes, total phenolic content, phenolic compounds profile, and antioxidant activity of buckwheat water- and milk-based mashes, flavored with cranberries and unflavored. The tested starter Fresco culture effectively fermented the buckwheat products and the viable cell counts of potentially probiotic bacteria were sufficient to demonstrate the health-promoting properties of final products. Lactic acid bacteria had a positive impact on total phenolic compound content, total flavonoid content, and antioxidant activity of buckwheat mashes, whereby final values (14 days) were higher by about 16.9–130.8%, 13.4–37.7%, and 14.5–145.9%, respectively, in comparison to initial values (0 h). Seven phenolic acids (gallic, protocatechuic, vanillic, syringic, caffeic, p-coumaric, and ferulic) and two flavonoids (rutin and quercetin) in buckwheat mashes were measured during the experimental period. The content of quercetin, gallic, and protocatechuic acids increased and, conversely, p-coumaric acid decreased, in all products. Prepared buckwheat fermented products have the potential to meet the criteria for potentially functional foods.

scholarly journals 1250. Novel Boronic Acid Transition State Analogs (BATSI) with in vitro inhibitory activity against class A, B and C β-lactamases

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S643-S643
Author(s):  
Maria F Mojica ◽  
Christopher Bethel ◽  
Emilia Caselli ◽  
Magdalena A Taracila ◽  
Fabio Prati ◽  
...  
Keyword(s):  
Active Site ◽  
Inhibitory Activity ◽  
Covalent Bond ◽  
Thiol Group ◽  
Viable Cell ◽  
Free Thiol ◽  
Transition State Analogs ◽  
Cell Counts ◽  
Free Thiol Group

Abstract Background Catalytic mechanisms of serine β-lactamases (SBL; classes A, C and D) and metallo-β-lactamases (MBLs) have directed divergent strategies towards inhibitor design. SBL inhibitors act as high affinity substrates that -as in BATSIs- form a reversible, dative covalent bond with the conserved active site Ser. MBL inhibitors bind the active-site Zn2+ ions and displace the nucleophilic OH-. Herein, we explore the efficacy of a series of BATSI compounds with a free-thiol group at inhibiting both SBL and MBL. Methods Exploratory compounds were synthesized using stereoselective homologation of (+) pinandiol boronates to introduce the amino group on the boron-bearing carbon atom, which was subsequently acylated with mercaptopropanoic acid. Representative SBL (KPC-2, ADC-7, PDC-3 and OXA-23) and MBL (IMP-1, NDM-1 and VIM-2) were purified and used for the kinetic characterization of the BATSIs. In vitro activity was evaluated by a modified time-kill curve assay, using SBL and MBL-producing strains. Results Kinetic assays revealed that IC50 values ranged from 1.3 µM to >100 µM for this series. The best compound, s08033, demonstrated inhibitory activity against KPC-2, VIM-2, ADC-7 and PDC-3, with IC50 in the low μM range. Reduction of at least 1.5 log10-fold of viable cell counts upon exposure to sub-lethal concentrations of antibiotics (AB) + s08033, compared to the cells exposed to AB alone, demonstrated the microbiological activity of this novel compound against SBL- and MBL-producing E. coli (Table 1). Table 1 Conclusion Addition of a free-thiol group to the BATSI scaffold increases the range of these compounds resulting in a broad-spectrum inhibitor toward clinically important carbapenemases and cephalosporinases. Disclosures Robert A. Bonomo, MD, Entasis, Merck, Venatorx (Research Grant or Support)

scholarly journals The immunity produced by a rough Salmonella dublin variant against Salmonella typhimurium and Salmonella choleraesuis infection in guinea-pigs

1966 ◽  
Vol 64 (3) ◽  
pp. 357-359 ◽  
Author(s):  
H. Williams Smith ◽  
Sheila Halls
Keyword(s):  
Salmonella Typhimurium ◽  
Guinea Pigs ◽  
Harmful Effect ◽  
Salmonella Dublin ◽  
Salmonella Choleraesuis

Vaccination with a rough variant of Salmonella dublin had no observable harmful effect on guinea-pigs. It conferred a good immunity against S. typhimurium and S. choleraesuis var kunzendorf infections.

scholarly journals Survival Strategy of Erwinia amylovora against Copper: Induction of the Viable-but-Nonculturable State

2006 ◽  
Vol 72 (5) ◽  
pp. 3482-3488 ◽  
Author(s):  
M�nica Ordax ◽  
Ester Marco-Noales ◽  
Mar�a M. L�pez ◽  
Elena G. Biosca
Keyword(s):  
Pathogenic Bacteria ◽  
Erwinia Amylovora ◽  
Control Plant ◽  
Viable Cell ◽  
Epifluorescence Microscopy ◽  
Survival Strategy ◽  
Vbnc State ◽  
Tetrazolium Chloride ◽  
Viable But Nonculturable ◽  
Cell Counts

ABSTRACT Copper compounds, widely used to control plant-pathogenic bacteria, have traditionally been employed against fire blight, caused by Erwinia amylovora. However, recent studies have shown that some phytopathogenic bacteria enter into the viable-but-nonculturable (VBNC) state in the presence of copper. To determine whether copper kills E. amylovora or induces the VBNC state, a mineral medium without copper or supplemented with 0.005, 0.01, or 0.05 mM Cu2+ was inoculated with 107 CFU/ml of this bacterium and monitored over 9 months. Total and viable cell counts were determined by epifluorescence microscopy using the LIVE/DEAD kit and by flow cytometry with 5-cyano-2,3-ditolyl tetrazolium chloride and SYTO 13. Culturable cells were counted on King's B nonselective solid medium. Changes in the bacterial morphology in the presence of copper were observed by scanning electron microscopy. E. amylovora entered into the VBNC state at all three copper concentrations assayed, much faster when the copper concentration increased. The addition of different agents which complex copper allowed the resuscitation (restoration of culturability) of copper-induced VBNC cells. Finally, copper-induced VBNC cells were virulent only for the first 5 days, while resuscitated cells always regained their pathogenicity on immature fruits over 9 months. These results have shown, for the first time, the induction of the VBNC state in E. amylovora as a survival strategy against copper.

scholarly journals The dynamic balance of import and export of zinc in Escherichia coli suggests a heterogeneous population response to stress

2015 ◽  
Vol 12 (106) ◽  
pp. 20150069 ◽  
Author(s):  
Hiroki Takahashi ◽  
Taku Oshima ◽  
Jon L. Hobman ◽  
Neil Doherty ◽  
Selina R. Clayton ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Zinc Concentration ◽  
Systems Approach ◽  
Model Simulation ◽  
Dynamic Balance ◽  
Model Fitting ◽  
Viable Cell ◽  
Population Heterogeneity ◽  
Cell Counts ◽  
Import And Export

Zinc is essential for life, but toxic in excess. Thus all cells must control their internal zinc concentration. We used a systems approach, alternating rounds of experiments and models, to further elucidate the zinc control systems in Escherichia coli . We measured the response to zinc of the main specific zinc import and export systems in the wild-type, and a series of deletion mutant strains. We interpreted these data with a detailed mathematical model and Bayesian model fitting routines. There are three key findings: first, that alternate, non-inducible importers and exporters are important. Second, that an internal zinc reservoir is essential for maintaining the internal zinc concentration. Third, our data fitting led us to propose that the cells mount a heterogeneous response to zinc: some respond effectively, while others die or stop growing. In a further round of experiments, we demonstrated lower viable cell counts in the mutant strain tested exposed to excess zinc, consistent with this hypothesis. A stochastic model simulation demonstrated considerable fluctuations in the cellular levels of the ZntA exporter protein, reinforcing this proposal. We hypothesize that maintaining population heterogeneity could be a bet-hedging response allowing a population of cells to survive in varied and fluctuating environments.

In Vitro Anti-Biofilm Activity of Hydrogen-Peroxide Generating Electrochemical Bandage Against Yeast Biofilms

2021 ◽  
Author(s):  
Yash S. Raval ◽  
Abdelrhman Mohamed ◽  
Jayawant N. Mandrekar ◽  
Cody Fisher ◽  
Kerryl E. Greenwood-Quaintance ◽  
...  
Keyword(s):  
Membrane Damage ◽  
Microscopic Analysis ◽  
Viable Cell ◽  
Wound Infections ◽  
Unique Challenge ◽  
Cell Membrane Damage ◽  
Cell Counts ◽  
Extensive Cell ◽  
Fluorescence Microscopic Analysis

Wound infections are caused by bacteria and/or fungi. The presence of fungal biofilms in wound beds presents a unique challenge, as fungal biofilms may be difficult to eradicate. The goal of this work was to assess the in vitro anti-biofilm activity of a H 2 O 2 -producing electrochemical bandage (e-bandage) against 15 yeast isolates representing commonly-encountered species. Time-dependent decreases in viable biofilm CFU counts of all isolates tested were observed, resulting in no visible colonies with 48 hours of exposure by plate culture. Fluorescence microscopic analysis showed extensive cell membrane damage of biofilm cells after e-bandage treatment. Reductions in intracellular ATP levels of yeast biofilm cells were recorded post e-bandage treatment. Our results suggest that exposure to H 2 O 2 -producing e-bandages reduce in vitro viable cell counts of yeast biofilms, making this a potential new topical treatment approach for fungal wound infections.

scholarly journals Evaluation of WGS-subtyping methods for epidemiological surveillance of foodborne salmonellosis.

2020 ◽  
Author(s):  
Manal Mohammed ◽  
Salina Thapa
Keyword(s):  
Salmonella Typhimurium ◽  
Multilocus Sequence Typing ◽  
Bacterial Infections ◽  
Outbreak Investigation ◽  
Whole Genome Sequence ◽  
Epidemiological Surveillance ◽  
Whole Genome ◽  
Salmonella Dublin ◽  
Source Of Infection ◽  
Investigation Methods

Abstract Background: Salmonellosis is one of the most common foodborne diseases worldwide. Although human infection by non-typhoidal Salmonella (NTS) enterica subspecies enterica is associated primarily with a self-limiting diarrhoeal illness, invasive bacterial infections (such as septicaemia, bacteraemia and meningitis) were also reported. Human outbreaks of NTS were reported in several countries all over the world including developing as well as high-income countries. Conventional laboratory methods such as pulsed field gel electrophoresis (PFGE) do not display adequate discrimination and have their limitations in epidemiological surveillance. It is therefore very crucial to use accurate, reliable and highly discriminative subtyping methods for epidemiological characterisation and outbreak investigation. Methods: Here, we used different whole genome sequence (WGS)-based subtyping methods for retrospective investigation of two different outbreaks of Salmonella Typhimurium and Salmonella Dublin that occurred in 2013 in UK and Ireland respectively. Results: Single nucleotide polymorphism (SNP)-based cluster analysis of Salmonella Typhimurium genomes revealed well supported clades, that were concordant with epidemiologically defined outbreak and confirmed the source of outbreak is due to consumption of contaminated mayonnaise. SNP-analyses of Salmonella Dublin genomes confirmed the outbreak however the source of infection could not be determined. The core genome multilocus sequence typing (cgMLST) was discriminatory and separated the outbreak strains of Salmonella Dublin from the non-outbreak strains that were concordant with the epidemiological data however cgMLST could neither discriminate between the outbreak and non-outbreak strains of Salmonella Typhimurium nor confirm that contaminated mayonnaise is the source of infection, On the other hand, other WGS-based subtyping methods including multilocus sequence typing (MLST), ribosomal MLST (rMLST), whole genome MLST (wgMLST), clustered regularly interspaced short palindromic repeats (CRISPRs), prophage sequence profiling, antibiotic resistance profile and plasmid typing methods were less discriminatory and could not confirm the source of the outbreak. Conclusions: Foodborne salmonellosis is an important concern for public health therefore, it is crucial to use accurate, reliable and highly discriminative subtyping methods for epidemiological surveillance and outbreak investigation. In this study, we showed that SNP-based analyses do not only have the ability to confirm the occurrence of the outbreak but also to provide definitive evidence of the source of the outbreak in real-time.

scholarly journals Statistical Study of the Spot-Plate Technique for Viable-Cell Counts

1963 ◽  
Vol 11 (4) ◽  
pp. 305-309
Author(s):  
A. F. Gaudy ◽  
F. Abu-Niaaj ◽  
E. T. Gaudy
Keyword(s):  
Statistical Study ◽  
Viable Cell ◽  
Plate Technique ◽  
Cell Counts
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