| 1. |
- Jacobsson, Gunnar, 1960, et al.
(författare)
-
Antibody responses in patients with invasive Staphylococcus aureus infections.
- 2010
-
Ingår i: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. - : Springer Science and Business Media LLC. - 1435-4373 .- 0934-9723. ; 29:6, s. 715-25
-
Tidskriftsartikel (refereegranskat)abstract
- Correlation between antibody response and clinical outcome in Staphylococcus aureus bacteremia has yielded conflicting results. Immunization schedules have failed in clinical trials. Is the humoral response toward S. aureus of protective nature? A prospective study was performed in patients with invasive S. aureus (ISA) infections during the period 2003-2005. The antibody levels were determined at the beginning and at the end of treatment and one month later (n = 96, n = 71, and n = 51, respectively). As controls, 115 healthy individuals were used. A quantitative enzyme-linked immunosorbent assay (ELISA) against eight purified antigens was performed. Bacterial isolates were grouped as to the production of alpha-toxin, agr type, and pulsed-field gel electrophoresis (PFGE) type. Large variations were seen in the antibody levels. The levels in the second sample were the highest. A correlation between agr group, PFGE group, alpha-toxin production, and initial antibody levels was observed. Patients with fatal outcome displayed lower initial antibody levels to all antigens and significantly so in regard to teichoic acid, lipase, enterotoxin A, and scalded skin syndrome toxin. In episodes with complicated bacteremia, initial significantly low levels to teichoic acid and lipase were registered. Low initial antibody levels against several antigens were associated with increased mortality and complicated bacteremia in invasive S. aureus infections. Bacterial properties, strain, and toxin production affected the antibody response.
|
|
| 2. |
|
|
| 3. |
- Bark, Tor, et al.
(författare)
-
Bacterial translocation after non-lethal hemorrhage in the rat
- 1993
-
Ingår i: Circulatory Shock. - : John Wiley & Sons. - 0092-6213. ; 41:1, s. 60-65
-
Tidskriftsartikel (refereegranskat)abstract
- Translocation of enteric bacteria has been suggested to compromise patients in severe catabolic stress. Mechanisms for this route of infection are not known. In this study, ratswere subjected to hemorrhage without reinfusion during 60 min, total blood loss was 3.28 +/- 0.14 ml/100 g BW. Control groups consisted of sham-operated animals without bleeding, and rats not operated at all. The mean number of viable bacteria found in mesenteric lymph nodes (MLN) of bled animals was 168 +/- 45 colony forming units (c.f.u./MLN), significantly higher compared to sham operated (5 +/- 3 c.f.u./MLN) and not operated (0 +/- 0 c.f.u./MLN) controls (P < 0.01). Cultures from MLN were positive in 7/9 rats after bleeding, in 3/9 of sham operated, and in 0/6 of non-instrumented control animals. No positive blood cultures were isolated. Escherichia coli was the dominant species found in MLN. A biochemical fingerprinting method (the PhP system) was used to identify translocating strains of E. coli among strains found in cecum. The method was also used to compare translocating strains between different animals. Our findings reveal that bacteria translocate to MLN after hemorrhage. Some phenotypes of E. coli strains translocate more frequently than others, suggesting that they have properties facilitating translocation.
|
|
| 4. |
- Bark, Tor, et al.
(författare)
-
Glutamine supplementation does not prevent bacterial translocation after non-lethal haemorrhage in rats
- 1995
-
Ingår i: European Journal of Surgery. - : Taylor & Francis Scandinavia. - 1102-4151 .- 1741-9271. ; 161:1, s. 3-8
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:To find out whether supplementation of an enteral diet with glutamine would reduce translocation of bacteria to mesenteric lymph nodes or blood after major haemorrhage in rats.DESIGN:Open randomised study.SETTING:University departments of surgery and microbiology, Sweden.MATERIAL:49 Sprague-Dawley rats.INTERVENTIONS:Rats were fed enterally for 7 days on diets supplemented with either glutamine or an isonitrogenous amount of non-essential amino acids. After feeding, 8 experimental and 8 control rats underwent sham operation; 9 and 7, respectively, underwent moderate haemorrhage (to 65 mm Hg); and 9 and 8, respectively, underwent severe haemorrhage (50 mm Hg) without reinfusion.MAIN OUTCOME MEASURES:Microbiological analyses of samples of blood and mesenteric lymph nodes taken 24 hours after haemorrhage.RESULTS:The median (interquartile) number of colony forming units/mesenteric lymph nodes after moderate haemorrhage in animals who were given glutamine supplementation was 11 (0-34) and in control animals 20 (0-178). After severe haemorrhage the corresponding figures were 199 (10-310) and 22 (0-187). No pathogens were isolated from blood cultures.CONCLUSION:Glutamine supplementation before haemorrhage did not reduce bacterial translocation to mesenteric lymph nodes in this rat model.
|
|
| 5. |
|
|
| 6. |
- Katouli, Mohammad, et al.
(författare)
-
Composition and diversity of intestinal coliform flora influence bacterial translocation in rats after hemorrhagic stress
- 1994
-
Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 2:11, s. 4768-4774
-
Tidskriftsartikel (refereegranskat)abstract
- Coliform bacteria are the most frequently reported bacteria to translocate afterhemorrhage. We investigated the correlation between composition and diversity of the cecal coliform flora and the degree of translocation in a rat model of hemorrhagic stress. Two groups of nine rats each were bled to 60 and 50 mm Hg mean arterial blood pressure, respectively. A sham-operated group without bleeding (n = 9) and a noninstrumented group (n = 6) served as controls. From each rat, 40 coliform isolates from the cecum and up to 16 from positive mesenteric lymph node (MLN) cultures were tested with an automated biochemical fingerprinting method. The phenotypic diversity of coliforms in each cecal sample was calculated as Simpson's diversity index (DI), and similarities between bacterial types in different samples were calculated as population similarity coefficients. Three rats in the sham-operated group and seven in each of the bled groups showed bacterial translocation. Of the different biochemical phenotypes (BPTs) found in the cecum of bled rats (mean, 6.5 BPTs), only a few were detected in MLNs (mean, 1.9 BPTs per MLN), with Escherichia coli being the dominant species. The translocating E. coli strains were mainly of two BPTs. Rats showing no translocation either did not carry these strains or had a high diversity of coliforms in the cecum. Furthermore, translocation of these coliform types was independent of their proportion in the cecum. In bled rats, the diversityof coliforms (mean DI, 0.53) was significantly higher than that in control groups (mean DI, 0.30; P = 0.004), suggesting that hemorrhage stimulates an increase in diversity of cecal coliforms. Rats with similar coliform flora and subjected to the same treatment showed similar patterns of translocation. Our results suggest that the composition of the coliformflora is an important factor in translocation and that certain coliform strains have the ability to translocate and survive in MLNs more easily than others.
|
|
| 7. |
- Katouli, Mohammad, et al.
(författare)
-
Selective translocation of coliform bacteria adhering to caecal epithelium of rats during catabolic stress
- 1997
-
Ingår i: Journal of Medical Microbiology. - : The Microbiology Society. - 0022-2615 .- 1473-5644. ; 46:7, s. 571-578
-
Tidskriftsartikel (refereegranskat)abstract
- Adult conventional rats were starved for 48 h with or without haemorrhage at 24 h, and translocation of caecal coliforms to mesenteric lymph nodes (MLNs) was measured. Translocation was detected in three of 11 rats without haemorrhage, in 6 of 11 starved and sham-operated rats and in 12 of 22 rats after haemorrhage. In contrast, only one of 13 non-instrumented and fed control rats showed translocation. Translocation was associated with more coliforms adhering to caecal epithelium in rats. Coliform isolates from caecum, caecal epithelium and MLNs were characterised and grouped into different biochemical phenotypes (BPTs) by a biochemical fingerprinting method. Of 291 BPTs detected in the caecum of all rats, 108 were also found on caecal epithelium; 36 BPTs were detected in MLNs, of which 17 were not detected either in the caecum or on the caecal epithelium of the corresponding rats. One isolate from each of these 36 BPTs was selected and compared to the others. Four common (C) BPTs (i.e., C1-C4) were identified among them. Strains of C1 formed the majority of isolates from the caecum (79%), caecal epithelium(71%) and MLNs (91%). In contrast, C2-C4 had a significantly lower incidence both in the caecum and on the caecal epithelium, but not in the MLNs. These findings indicate that not all caecal coliforms adhere to the epithelium during catabolic stress and that for translocation to occur, other bacterial properties besides adhesion are needed. It is also concluded that coliforms with a low incidence in the caecum can translocate with the same efficiency as those with a high incidence.
|
|
| 8. |
- Katouli, M, et al.
(författare)
-
Virulence characteristics of Escherichia coli strains causing acute cystitis in young adults in Iran.
- 2005
-
Ingår i: The Journal of infection. - : Elsevier BV. - 0163-4453. ; 50:4, s. 312-21
-
Tidskriftsartikel (refereegranskat)abstract
- Escherichia coli strains that cause cystitis posses virulence properties that facilitate their colonisation and persistence in the bladder. In Iran, despite the high number of the urinary tract infections, very few studies has been done to determine the role of these virulence properties in the pathogenesis of E. coli cyctitis.
|
|
| 9. |
- Nettelbladt, Carl Gustaf, et al.
(författare)
-
Bulking fibre prevents translocation of an efficiently translocating Escherichia coli strain in rats
- 1998
-
Ingår i: Clinical Nutrition. - : Elsevier. - 0261-5614 .- 1532-1983. ; 17:4, s. 185-190
-
Tidskriftsartikel (refereegranskat)abstract
- Background: starvation for 24 h prior to experimental haemorrhage increases bacterial translocation in rats. Forty-eight hours starvation alone causes pronounced microbiological changes in caecal contents and a marked increase in bacterial adherence to caecal epithelium. The aim of the present study was to examine whether bulking fibre prevents these microbiological changes induced by starvation, i.e. mucosal adherence and/or bacterial translocationwith and without haemorrhage in rats. Methods: 32 rats were inoculated with the translocating Escherichia cell strain KI-C1. Groups of these rats were then starved for 48 h with or without access to bulking fibre. An additional group of rats was given bulking fibre and subjected to haemorrhage. A control group was untreated and given regular food. Samples were taken from caecal contents, caecal epithelium, mesenteric lymph nodes and blood. A biochemical fingerprinting method was used to characterize and compare E. coil strains in all samples. Results: ingestion of bulking fibre alone for 48 h significantly reduced the frequency of KI-C1 both in caecal contents and on caecal epithelium and completely prevented translocation of the strain, compared to starvation without bulking fibre for 48 h. Enforced stress (haemorrhage) increased bacterial translocation to the same level as starvation for 48 h. E. coli phenotypes found in mesenteric lymph nodes were also found adhering to the caecal epithelium. Conclusions: the presence of bulking fibre in gut lumen, by unknown mechanisms, reduces the frequency of an inoculated translocating strain of E. coil in caecal contents and on caecal epithelium and prevents its translocationto mesenteric lymph nodes.
|
|
| 10. |
|
|
| 11. |
- Nettelbladt, C. G., et al.
(författare)
-
Starvation increases the number of coliform bacteria in ceacum and induces bacterial adherence to caecal epithelium in rats
- 1997
-
Ingår i: European Journal of Surgery. - Stockholm, Sweden : Taylor & Francis. - 1102-4151 .- 1741-9271. ; 163:2, s. 135-142
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the impact of starvation for 24 and 48 h on the number of coliform bacteria in the caecal contents, on the mucosal adherence of coliform bacteria, and on bacterial translocation in rats.Design: Open prospective study.Setting: University departments of surgery and microbiology, Sweden.Material: 46 adult male Sprague-Dawley rats.Interventions: 19 rats served as controls, and were fed until samples were taken. Six animals were starved for 24 h and another 15 for 48 h, with free access to water, and then anaesthetised before blood, mesenteric lymph nodes (MLN), caecum, and caecal contents were sampled. To verify bacterial translocation in this strain of rats, another six rats underwent controlled haemorrhage for 60 min to reduce the blood pressure to 55 mm Hg mean arterial pressure (MAP). These rats had free access to food and water before haemorrhage but were allowed only water until samples were taken 24 h after haemorrhage.Main Outcomes Measures: Presence and number of coliform bacteria in samples taken from caecal contents, caecal epithelium, MLN, and blood.Results: Starvation for 24 h increased the number of coliform bacteria (colony forming units (CFU)/g) in the caecal contents 25-fold (p < 0.05). Starvation for 48 h further increased the number by a factor of 100. The number of coliform bacteria that adhered to the caecal epithelium increased 3,000 times in rats that had been starved for 48 h (p < 0.001). There was no significant difference in translocation (as indicated by cultures from MLN) between rats that had been fed and those that had been starved for 48 h. In 4 of the 6 rats that were bled and then starved for 24 h there were signs of bacterial translocation, which was significantly more than the 1/19 in fed rats (p < 0.05).Conclusion: Starvation increases the number of bacteria in the caecal contents and increases bacterial adherence to the caecal epithelium. These changes may contribute to the previously reported increase in bacterial translocation in starved compared wit fed rats that were subjected to stress. The same changes in the gut were observed in animals subjected to haemorrhagic stress in addition to starvation, and in which bacterial translocation was evident.
|
|
| 12. |
- Winberg, J, et al.
(författare)
-
The PapG-adhesin at the tip of P-fimbriae provides Escherichia coli with a competitive edge in experimental bladder infections of cynomolgus monkeys.
- 1995
-
Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 182:6, s. 1695-702
-
Tidskriftsartikel (refereegranskat)abstract
- Human urinary tract infection is an infectious disease that depends on a series of host-microbial interactions. The bacteria first colonize the colon and then the periurethral/vaginal areas; they ascend to and infect first the bladder and then the kidneys. Expression of Escherichia coli P-fimbriae constitutes the strongest correlation to renal pathogenicity, but is also related to first-time cystitis in children. The role of P-fimbriae in the preceding steps in the infectious process is unknown. To examine this, we constructed, from a P-fimbriated E. coli strain with a class II G-adhesin preferentially binding to globoside, one isogenic mutant lacking the G-adhesin and another isogenic mutant in which we replaced the papG class II allele with a class III adhesin preferentially binding to the Forssman antigen. We report here the comparison of the adhesin knockout mutant (DS17-8) and the class-switch mutant (DS17-1) with the wild-type (DS17) for in vivo colonization of the gut, vagina, and bladder of cynomolgus monkeys. It was recently shown that the class II tip G-adhesin is a prerequisite for acute pyelonephritis to occur in the monkey model in the absence of other kidney-specific adhesins or obstruction of the urinary flow. Here we show that it is not required for bladder infection but gives a competitive advantage in mixed infections. In the vagina and colon, the G-adhesin gives no competitive advantage.
|
|
| 13. |
- Zabarovska, Veronika, et al.
(författare)
-
NotI passporting to identify species composition of complex microbial systems
- 2003
-
Ingår i: Nucleic Acids Research. - Oxford, United Kingdom : Oxford University Press. - 0305-1048 .- 1362-4962. ; 31:2, s. E5-5
-
Tidskriftsartikel (refereegranskat)abstract
- We describe here a new method for large-scale scanning of microbial genomes on a quantitative and qualitative basis. To achieve this aim we propose to create NotI passports: databases containing NotI tags. We demonstrated that these tags comprising 19 bp of sequence information could be successfully generated using DNA isolated from intestinal or fecal samples. Such NotI passports allow the discrimination between closely related bacterial species and even strains. This procedure for generating restriction site tagged sequences (RSTS) is called passporting and can be adapted to any other rare cutting restriction enzyme. A comparison of 1312 tags from available sequenced Escherichia coli genomes, generated with the NotI, PmeI and SbfI restriction enzymes, revealed only 219 tags that were not unique. None of these tags matched human or rodent sequences. Therefore the approach allows analysis of complex microbial mixtures such as in human gut and identification with high accuracy of a particular bacterial strain on a quantitative and qualitative basis.
|
|
| 14. |
|
|
| 15. |
- Zabarovsky, Eugene R, et al.
(författare)
-
Restriction site tagged (RST) microarrays : a novel technique to study the species composition of complex microbial systems
- 2003
-
Ingår i: Nucleic Acids Research. - Oxford, United Kingdom : Oxford University Press. - 0305-1048 .- 1362-4962. ; 31:16, s. e95-
-
Tidskriftsartikel (refereegranskat)abstract
- We have developed a new type of microarray, restriction site tagged (RST), for example NotI, microarrays. In this approach only sequences surrounding specific restriction sites (i.e. NotI linking clones) were used for generating microarrays. DNA was labeled using a new procedure, NotI representation, where only sequences surrounding NotI sites were labeled. Due to these modifications, the sensitivity of RST microarrays increases several hundred-fold compared to that of ordinary genomic microarrays. In a pilot experiment we have produced NotI microarrays from Gram-positive and Gram-negative bacteria and have shown that even closely related Escherichia coli strains can be easily discriminated using this technique. For example, two E.coli strains, K12 and R2, differ by less than 0.1% in their 16S rRNA sequences and thus the 16S rRNA sequence would not easily discriminate between these strains. However, these strains showed distinctly different hybridization patterns with NotI microarrays. The same technique can be adapted to other restriction enzymes as well. This type of microarray opens the possibility not only for studies of the normal flora of the gut but also for any problem where quantitative and qualitative analysis of microbial (or large viral) genomes is needed.
|
|
