CAPSULAR POLYSACCHARIDES OF ESCHERICHIA COLI, TYPES K28A AND K34A

1958 ◽  
Vol 4 (5) ◽  
pp. 505-516 ◽  
Author(s):  
Bill B. Wiley ◽  
Henry W. Scherp

Examination of Escherichia coli isolates from 100 diagnostic stool, urine, or blood cultures yielded 13 mucoid strains, identified by strict biochemical criteria. Specific capsular and agglutination reactions identified four strains as K28A (O group 8), four as K34A (O group 9), and two as K42A, whereas three strains were serologically distinct from each other and from the recorded A types.Polysaccharides, identified as the respective capsular materials by inhibition of the specific capsular reactions, were isolated from a K28A strain and a K34A strain, grown in a chemically defined medium. The serological individuality of these polysaccharides correlated with a difference in their component monosaccharides, as determined by chromatography and colorimetry. Both contained galactose, glucose, mannose, and from 10 to 14% of a hexuronic acid, but the K28A polysaccharide contained in addition 13% of fucose.Normal human sera collected in the Rochester area contained antibodies to the K28A and K34A polysaccharides very infrequently and in very low titer. On the other hand, two thirds of such sera contained O group 8 antibody and the other third contained O group 9 antibody, both in much higher titer.

1980 ◽  
Vol 84 (1) ◽  
pp. 1-10 ◽  
Author(s):  
B. Adler ◽  
S. Faine

SUMMARYLeptospires (Leptospira interrogausserovarpomona) grown in chemically defined medium were immunogenic when given intradermally in humans if the leptospires were killed with formalin but not if they were boiled. Boiled leptospires were immunogenic for rabbits and hamsters and protected hamsters from challenge infection. On the other hand, boiled leptospires of thebiflexacomplex, serovarpatoc, did retain some immunogenicity in humans, but the antisera did not protect hamsters against challenge with serovar pomona.


2020 ◽  
Vol 47 (12) ◽  
pp. 1117-1132
Author(s):  
Katharina Novak ◽  
Juliane Baar ◽  
Philipp Freitag ◽  
Stefan Pflügl

AbstractThe aim of this study was to establish isobutanol production on chemically defined medium in Escherichia coli. By individually expressing each gene of the pathway, we constructed a plasmid library for isobutanol production. Strain screening on chemically defined medium showed successful production in the robust E. coli W strain, and expression vector IB 4 was selected as the most promising construct due to its high isobutanol yields and efficient substrate uptake. The investigation of different aeration strategies in combination with strain improvement and the implementation of a pulsed fed-batch were key for the development of an efficient production process. E. coli W ΔldhA ΔadhE Δpta ΔfrdA enabled aerobic isobutanol production at 38% of the theoretical maximum. Use of cheese whey as raw material resulted in longer process stability, which allowed production of 20 g l−1 isobutanol. Demonstrating isobutanol production on both chemically defined medium and a residual waste stream, this study provides valuable information for further development of industrially relevant isobutanol production processes.


1983 ◽  
Vol 104 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Paul V. Holmes ◽  
Per O. Janson ◽  
Jan Sogn ◽  
Björn Källfelt ◽  
William J. LeMaire ◽  
...  

Abstract. Both ovaries of 31 rabbits were perfused with a chemically defined medium in vitro in a recirculation system. In one series of experiments, hCG (100 IU) was injected iv 5–6 h prior to anaesthesia and surgery. Approximately 1 h later the perfusion was started. One ovary was perfused as control while the other ovary was perfused with 5 μg/ml indomethacin or with indomethacin and 1 μg/ml PGF2α. In another series of experiments the rabbits received no pretreatment prior to operation. Instead, bovine LH was added to the perfusion medium of both control and experimental ovaries. The experimental side also received either indomethacin or indomethacin and PGF2α. Finally, the effect of PGF2α in the absence of LH was compared to the control ovary receiving only LH. After injection of hCG in vivo, ovulations occurred in 4 of 5 control ovaries. Indomethacin completely blocked ovulation in 4 of the 5 ovaries treated, while PGF2α restored ovulations in all the experimental ovaries. In the group of experiments where LH was added in vitro, ovulations were induced in all ovaries treated with varying LH doses. Furthermore, indomethacin blocked ovulation in 5 out of 7 ovaries, and PGF2α restored ovulation in all ovaries. Fifty per cent of the ovaries treated only with PGF2α (in the absence of LH) also ovulated. The pattern of steroid release did not differ between control ovaries, indomethacin treated ovaries, and indomethacin + PGF2α treated ovaries. Ovaries treated in perfusion with PGF2α alone had very low steroid levels compared to the ovaries treated with LH. This study confirms that indomethacin blocks ovulation in the perfused rabbit ovary and that this blockade can be overcome by exogenous PGF2α. Indomethacin and PG-treatments after ovulation induction did not affect ovarian steroidogenesis. Furthermore, while PGF2α was able to induce ovulations in these perfused oestrous ovaries in the absence of LH, it did not stimulate steroidogenesis.


1965 ◽  
Vol 6 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Susan Hollom ◽  
R. H. Pritchard

From studies involving inhibition of DNA synthesis in Hfr strains ofEscherichia coliK12, either by thymine starvation (Pritchard, 1963) or amino-acid starvation (Suit, Matney, Doudney & Billen, 1964), during mating withF−strains, it has been concluded that transfer of DNA from males to females can occur in the absence of DNA synthesis. This conclusion is at variance with the hypothesis (Jacob, Brenner & Cuzin, 1963) that the energy required for transfer is derived from the process of DNA replication. On the other hand, a second prediction from this hypothesis, that one polynucleotide chain of the DNA transferred during mating will have been synthesized during transfer, is strongly supported by recent experiments (Ptashne, 1965; Blinkova, Bresler & Lanzov, 1965; Gross & Caro, 1965).


2018 ◽  
Vol 6 (11) ◽  
pp. 2023-2029 ◽  
Author(s):  
Sayed Yousef Mojtahedi ◽  
Aliakbar Rahbarimanesh ◽  
Leila Khedmat ◽  
Anahita Izadi

AIM: The objective of this study was to evaluate the frequency of risk factors for bacteremia in children less than 15 years of age was determined in Bahrami Hospital during 2013-2016. METHODS: This study conducted on 84 children aged 3 months’ to15 years old, who hospitalised in the pediatrics ward and the PICU in Bahrami Hospital from 2012 to 2016. Our study consisted of 46 boys (54.2%) and 38 girls. Moreover, 24.1% of subjects (20 patients) were entered in the study as young as three months old, followed by three months to three years (49.4 %; 41 subjects), and 3 to 15 years of age (26.5%; 22 individuals). RESULTS: The average hospitalization duration was determined to be 15.30 ± 8.75 days. Moreover, our results revealed that a history of blood transfusion in 11.2% of patients. On the other hand, 35.7% of cases were determined to be positive for blood cultures. The microorganisms reported from positive blood cultures include Enterobacter (81.48%), Escherichia coli (11.11%) and Klebsiella (3.70%). Also, 50% of patients were hospitalised in the internal ward, 12% received immunosuppressive drugs, and 96.4% of the patients had a history of vaccination. CONCLUSION: Pediatric severe sepsis remains a burdensome public health problem, with prevalence, morbidity, and mortality rates similar to those reported in critically ill adult populations. International clinical trials targeting children with severe sepsis are warranted.


2020 ◽  
pp. 73-79

This is the first study that investigated the microbial factor as biomarker in autistic children and discuss roles of this factor in the pathogenesis of autism. The participants in current study were 145 persons, only 50 sample of stool could collected (35 autistic children and 15 healthy children). Autistic children were attended to autism unit at Disabled Hospital in Thi-Qar province, Iraq during the period from January to November 2016. The results showed males (81%) more than female (19%) with ratio 4:1 and also results explain the age group of 3-5 years recorded the highest percentage (41.05%). Distribution of autistic children according to sibling showed six were brotherly with occurrence rate 6.3%. Stool samples were subjected to examination and culture. The total aerobic count of isolated bacteria was 140 isolates. Gram-negative isolates were identified by API Enterobacteriaceae system. The results were Escherichia coli, Enterobacter cloacae, Klebsiella pneumonia, Pseudomonas aeruginosa and Proteus mirabilis with percentage 38.5%, 19.23%, 11.53%,7.69%, and 3.84% respectively. On the other hand, gram positive cocci isolates included Enterococcus faecalis, Staphylococcus aureus and Staph. epidermidis with percentage 11.53%, 4.80% and 2.88% respectively. A significant difference (P≤0.05) was recorded between bacterial isolates. Quantity and quality of isolated bacteria (colony/g *104) were done. E.coli isolates were the highest count with 261*104 colony/g while, Staphylococci epidermidis were recorded the worse colony count with 30*104 colony/g. The quality results showed Escherichia coli the most common gram negative bacterial isolates (38.46%). On the other hand, the highest gram positive cocci isolates were included Enterococcus faecalis (11.53%), with significant difference (P≤0.05) between bacterial isolates. The ability of bacterial isolates to produce histidine decarboxylase was examined on Niven medium. The positive result include colonies with purple halo around them. Only 10 isolates (25%) from all isolates were produce histidine belong to E.coli. On other hand, result of parasite examination explain no parasite in all samples. From this study can conclusion the altered gut microflora may play an essential role in the pathogenesis of autism. Despite the accurate evidence, this etiological heterogeneity is still not recognized by autism researchers, and most studies fail to take it into account.


2010 ◽  
Vol 25 (9) ◽  
pp. 1761-1770 ◽  
Author(s):  
Abdul-Majeed Azad ◽  
Ryan Hershey ◽  
Saqib Ali ◽  
Vijay Goel

This paper reports the development of nonwoven nanofibers of pure and iron-doped titanium dioxide (TiO2) and evaluation of their antimicrobial attributes for using them as disinfectant gauze for wound healing upon brief activation by ultraviolet/infrared (UV/IR) illumination. It was found that the fibers exhibited superior bactericidal affinity when exposed briefly (3–12 s) to either multiphoton laser or infrared radiations. On the other hand, exposure to a UV beam for up to 20 min was not effective in mitigating the bacterial colonization of the Escherichia coli.


1991 ◽  
Vol 23 (1-3) ◽  
pp. 261-270 ◽  
Author(s):  
Goen E. Ho ◽  
Robyn A. Gibbs ◽  
Kuruvilla Mathew

Column experiments were conducted to determine the improvement in the removal of Escherichia coli, Salmonella adelaide and poliovirus-1 through sands by amendment with bauxite refining residue. The residue (red mud) was neutralized using 5 % gypsum and incorporated to form 30% of the amended sands. In 65 cm long soil columns the removal of the three organisms in the amended sand columns was excellent with over seven orders of magnitude reduction in concentration. Removal in unamended sands was poor. From breakthrough curves in unamended sand columns filtration, die-off and adsorption all appear to play a role in organism removal. The results also show that E. coli can be used as an indicator for contamination, though S.adelaide was less efficiently removed than E. coli. Poliovirus was on the other hand better removed than E. coli.


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