Plasmid replication and partition in E. coli, and sex pheromones and plasmid transfer in Streptococcus faecalis.

Transfer by mobilization of a pBR derivative recombinant plasmid lacking transfer functions (oriT+, tra−, mob−) from one E. coli K12 strain to another was investigated in seven sterile microcosms corresponding to different environments. These microcosms were chosen as representative of environments that genetically engineered microorganisms (GEMOs) encounter after accidental release, namely attached biomass in aquatic environments (biofilm), soil, seawater, freshwater, wastewater, mouse gut, and mussel gut. GEMOs survived in the same way as the host strains in all microcosms. Recombinant DNA mobilization occurred in the mouse gut, in sterile soil, and in biofilm. The plasmid transfer rates principally reflected the environmental conditions encountered in each microcosm.Key words: recombinant DNA, plasmid transfer, mobilization, conjugation, microcosm.

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Growth and Death of Selected Microorganisms in Ultrafiltered Milk

Journal of Food Protection ◽

10.4315/0362-028x-49.3.233 ◽

1986 ◽

Vol 49 (3) ◽

pp. 233-235 ◽

Cited By ~ 6

Author(s):

PATRICIA HAGGERTY ◽

NORMAN N. POTTER

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Skim Milk ◽

Laboratory Scale ◽

The Other ◽

Streptococcus Faecalis ◽

E Coli ◽

Milk Samples ◽

D Values ◽

D Value

Studies were made to compare the growth and death of Staphylococcus aureus, Streptococcus faecalis and Escherichia coli in skim milk concentrated by ultrafiltration to that in unconcentrated skim milk. Skim milk was volume concentrated to 2× in laboratory-scale stirred UF cells. Behavior of the organisms was analyzed in four inoculated milk samples: 2× retentate, 1× water-diluted retentate, milk equivalent (retentate plus permeate) and unconcentrated skim milk. Growth of each organism and of total aerobes did not vary in the four milk samples at either 7 or 13°C. For S. faecalis and E. coli, D-values for samples heated to 62.7°C did not significantly differ in the four milk samples (p>0.01). The D-value of S. aureus in water-diluted retentate was slightly but significantly lower than those in the other three milk samples (p<0.01), possibly due to the lowered lactose level in this sample.

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SOME OBSERVATIONS OF THE EFFECT OF FILTRATES OF SEVERAL REPRESENTATIVE CONCOMITANT BACTERIA ON CLOSTRIDIUM BOTULINUM TYPE A

Canadian Journal of Microbiology ◽

10.1139/m61-072 ◽

1961 ◽

Vol 7 (4) ◽

pp. 633-639 ◽

Cited By ~ 7

Author(s):

F. D. Crisley ◽

G. E. Helz

Keyword(s):

Escherichia Coli ◽

Phosphate Buffer ◽

Clostridium Botulinum ◽

Type A ◽

Complete Medium ◽

Clostridium Sporogenes ◽

Streptococcus Faecalis ◽

E Coli ◽

Botulinum Type ◽

High Concentrations

Filtrates of growing cultures of Bacillus sphacricus, Clostridium sporogenes, Escherichia coli, and Streptococcus faecalis inhibited germination of spores of Clostridium botulinum type A. Of the four filtrates only that of E. coli was inactive at low (1:8) concentrations, and all were inhibitory at high (1:2) levels. Only filtrates of B. sphaericus and C. sporogenes affected lysis (increased) of washed cells of C. botulinum, and only S. faecalis filtrate altered botulinal toxigenicity in a complete medium. S. faecalis filtrate enhanced the final toxicity when present in high concentrations in the presence of phosphate buffer.

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Sex pheromones and plasmid transfer in Enterococcus faecalis

Plasmid ◽

10.1016/0147-619x(89)90041-3 ◽

1989 ◽

Vol 21 (3) ◽

pp. 175-184 ◽

Cited By ~ 61

Author(s):

Don B. Clewell ◽

Keith E. Weaver

Keyword(s):

Enterococcus Faecalis ◽

Sex Pheromones ◽

Plasmid Transfer

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Evaluation of Live Bacterial Prophylactics to Decrease IncF Plasmid Transfer and Association With Intestinal Small RNAs

Frontiers in Microbiology ◽

10.3389/fmicb.2020.625286 ◽

2021 ◽

Vol 11 ◽

Author(s):

Graham A. J. Redweik ◽

Mary Kate Horak ◽

Ryley Hoven ◽

Logan Ott ◽

Melha Mellata

Keyword(s):

Virulence Genes ◽

Positive Association ◽

Multidrug Resistant ◽

Plasmid Transfer ◽

Siderophore Production ◽

Causal Mechanism ◽

Bacterial Gene ◽

E Coli ◽

Bacterial Gene Expression

Chicken intestinal Escherichia coli are a reservoir for virulence and antimicrobial resistance (AMR) genes that are often carried on incompatibility group F (IncF) plasmids. The rapid transfer of these plasmids between bacteria in the gut contributes to the emergence of new multidrug-resistant and virulent bacteria that threaten animal agriculture and human health. Thus, the aim of the present study was to determine whether live bacterial prophylactics could affect the distribution of large virulence plasmids and AMR in the intestinal tract and the potential role of smRNA in this process. In this study, we tested ∼100 randomly selected E. coli from pullet feces (n = 3 per group) given no treatment (CON), probiotics (PRO), a live Salmonella vaccine (VAX), or both (P + V). E. coli isolates were evaluated via plasmid profiles and several phenotypic (siderophore production and AMR), and genotypic (PCR for virulence genes and plasmid typing) screens. P + V isolates exhibited markedly attenuated siderophore production, lack of AMR and virulence genes, which are all related to the loss of IncF and ColV plasmids (P < 0.0001). To identify a causal mechanism, we evaluated smRNA levels in the ceca mucus and found a positive association between smRNA concentrations and plasmid content, with both being significantly reduced in P + V birds compared to other groups (P < 0.01). To test this positive association between IncF plasmid transfer and host smRNA concentration, we evenly pooled smRNA per group and treated E. coli mating pairs with serial concentrations of smRNA in vitro. Higher smRNA concentrations resulted in greater rates of IncF plasmid transfer between E. coli donors (APEC O2 or VAX isolate IA-EC-001) and recipient (HS-4) (all groups; P < 0.05). Finally, RNAHybrid predictive analyses detected several chicken miRNAs that hybridize with pilus assembly and plasmid transfer genes on the IncF plasmid pAPEC-O2-R. Overall, we demonstrated P + V treatment reduced smRNA levels in the chicken ceca, which was associated with a reduction in potentially virulent E. coli. Furthermore, we propose a novel mechanism in which intestinal smRNAs signal plasmid exchange between E. coli. Investigations to understand the changes in bacterial gene expression as well as smRNAs responsible for this phenomenon are currently underway.

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PENGARUH SPESIES BAKTERI DAN RATIO SPERMATOZOA/BAKTERI TERHADAP VITALITAS SPERMATOZOA MANUSIA SECARA IN VITRO

Journal of Biological Researches ◽

10.23869/bphjbr.7.1.20015 ◽

2001 ◽

Vol 7 (1) ◽

pp. 41-46

Author(s):

Sukarjati Sukarjati ◽

Hamdani Lunardhi

Keyword(s):

Detrimental Effect ◽

Enterobacter Aerogenes ◽

Negative Influence ◽

Percoll Gradient ◽

Streptococcus Faecalis ◽

E Coli ◽

Infertile Men ◽

Column Method ◽

Fluid Culture

The effect of some pecies of bacteria and sperm/bacteria ratio on sperm vitality has been studied. Four species of bacteria were used in this study: Stapylococcus epidermidis, Streptococcus faecalis, Enterobacter aerogenes were obtained from semen culture of infertile men and E. coli was obtained from prostaltic fluid culture from men with prostat and urinary system disturbances. Five semen samples fulfilling the WHO criteri (1992) were used in this study. After preparation by Percoll gradient-column method, sperm were inoculated in a microplate with Stapylococcus epidermidis, Streptococcus faecalis, Enterobacter aerogenes and E. coli under the sperm/bacteria ratio 1:10 and 1:1000. Sperm vitality was observed immediately, 3 and 6 hours after inoculation. At the second experiment, the detrimental influence of bacteria on sperm was prevented by adding penicillin. Result of this study indicated that Stapylococcus epidermidis, Streptococcus faecalis, and Enterobacter aerogenes were not affected on the sperm vitality. The effect of E. coli on sperm vitality occurred at the ratio of sperm/bacteria 1:10 after 3 and 6 hours incubation and at the ratio of sperm/bacteria 1:1000 occurred after 6 hours incubation. It might be concluded that the negative influence of bacteria on sperm vitality in vitro, is dependent in species of bacteria, bacteria concentration, and time of incubation. The most detrimental effect on sperm vitality was shown by E. coli at the ratio of sperm/bacteria 1:10 after 6 hours incubation. The detrimental effecr was not prevented bt the addition of penicillin.

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Conjugation dynamics of self-transmissible and mobilisable plasmids intoE. coliO157:H7 onArabidopsis thalianarosettes

10.1101/375402 ◽

2018 ◽

Cited By ~ 4

Author(s):

Mitja N.P. Remus-Emsermann ◽

Cosima Pelludat ◽

Pascal Gisler ◽

David Drissner

Keyword(s):

Antibiotic Resistance ◽

Pathogenic Bacteria ◽

Antibiotic Resistance Genes ◽

Laboratory Strain ◽

Time Frame ◽

Plasmid Transfer ◽

Intermediate Hosts ◽

E Coli ◽

Plant Parts ◽

Human Pathogenic Bacteria

AbstractMany antibiotic resistance genes present in human pathogenic bacteria are believed to originate from environmental bacteria and conjugation of antibiotic resistance conferring plasmids is considered to be one of the major reasons for the increasing prevalence of antibiotic resistances. A hotspot for plasmid-based horizontal gene transfer is the phyllosphere,i.e.the surfaces of aboveground plant parts. Bacteria in the phyllosphere might serve as intermediate hosts with transfer capability to human pathogenic bacteria. In this study, the exchange of mobilisable and self-transmissible plasmids via conjugation was evaluated. The conjugation from the laboratory strainE. coliS17-1, the model phyllosphere colonizerPantoea eucalypti299R, and the model pathogenE. coliO157:H7∆stxto the recipient strainE. coliO157:H7∷MRE1O3∆stxin the phyllosphere ofArabidopsis thalianawas determined. The results suggest that short-term occurrence of a competent donor is sufficient to fix plasmids in a recipient population ofE. coliO157:H7∷MRE1O3∆stx. The spread of self-transmissible plasmids was limited after initial steep increases of transconjugants that contributed up to 10% of the total recipient population. The here-presented data of plasmid transfer will be important for future modelling approaches to estimate environmental spread of antibiotic resistance in agricultural production environments.ImportanceThis study investigated the transfer of antibiotic resistance conferring plasmids to enteropathogenicE. colion plant leaf surfaces. The results indicate that plasmid transfer may be high within the first 24 hours after inoculation. Transconjugant populations are maintained and stable for a considerable time frame on plant leaves, but invasion of the plasmid to the recipient population is limited.

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COMPARISON OF ESCHERICHIA COLI AND STREPTOCOCCUS FAECALIS AS A TEST ORGANISM TO DETERMINE THE SANITARY QUALITY OF FOOD1 PART I

Journal of Milk and Food Technology ◽

10.4315/0022-2747-17.7.204 ◽

1954 ◽

Vol 17 (7) ◽

pp. 204-218 ◽

Cited By ~ 1

Author(s):

C. H. Allen ◽

F. W. Fabian

Keyword(s):

Escherichia Coli ◽

Pathogenic Bacteria ◽

Intestinal Tract ◽

Bacterial Contamination ◽

Test Organism ◽

Enteric Bacteria ◽

Streptococcus Faecalis ◽

E Coli ◽

Suitable Organism

Since the discovery of the role that bacteria play in disease, a search has been made for a suitable organism that would be indicative of dangerous bacterial contamination in food. Early work with pathogenic bacteria indicated that they would not be suitoble to serve this purpose since they were hard to isolate, were too fastidious, and died off quickly under conditions favorable for keeping food. For these and other reasons the search turned to other bacteria associated with pathogenic bacteria but which were hardier and easier to work with and identify. Fullfilling these requirements were two organisms, E. coli and Strept. faecalis, normal inhabitants of the intestinal tract and associated with many pathogenic bacteria especiallv the enteric bacteria which ore responsible for many food outbreaks. Today the presence of moderate numbers of these organisms is not considered a sure sign of dangerous contamination but rather of possible contamination. Their presence indicates that a search for the cause of the contamination should be made.

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