Olle Aspevall

Performance of Four Chromogenic Urine Culture Media after One or Two Days of Incubation Compared with Reference Media

ABSTRACT Four chromogenic urine culture media were compared to culture on blood agar, MacConkey agar, and CLED (cysteine-, lactose-, and electrolyte-deficient) agar for detection of uropathogens in 1,200 urine specimens. After 2 nights of incubation, 96% of all isolates were recovered on blood agar, 96% were recovered on CLED agar, 92% were recovered on CPS ID2, 96% were recovered on CHROMagar Orientation from BBL, 95% were recovered on CHROMagar Orientation from The CHROMagar Company, and 95% were recovered on Chromogenic UTI Medium.

Activation of Extracellular Signal-Regulated Kinase Mediates Apoptosis Induced by Uropathogenic Escherichia coli Toxins via Nitric Oxide Synthase: Protective Role of Heme Oxygenase-1

Pyelonephritis is a risk factor for renal tubular epithelial cell damage in children. The inter- and intracellular regulator nitric oxide (NO) plays a role in the modulation of cellular viability in urinary tract infections, but the role of the NO pathway in renal proximal tubular-cell death remains unclear. The present study demonstrates that, in renal epithelial cells undergoing death mediated by Escherichia coli strain ARD6 serotype O6K13H1 (O6), levels of the phosphorylated extracellular signal-regulated kinase (ERK) 1/2 and inducible NO synthase (iNOS) proteins are up-regulated, but levels of endothelial NO synthase are down-regulated. When NO synthase (NOS) activity is inhibited by the specific inhibitor of NOS or mitogen-activated protein kinase kinase, cells are prevented from death. Moreover, down-regulating protein 53 (p53) does not prevent the cells from dying, although p53 is up-regulated in O6-exposed cells. Up-regulation of heme oxygenase (HO)-1 by sodium nitroprusside or by the specific activator hemin inhibits cell death. In conclusion, the activation of ERK mediates O6 toxin-mediated renal cell death via induction of iNOS. Stimulation of HO-1 protects cells against death.

Meningitis due to gemella haemolysans after neurosurgical treatment of trigeminal neuralgia

We report a case of meningitis due to Gemella haemolysans. An 82-year-old man with trigeminal neuralgia and senile dementia developed signs of meningitis 24 h after retrogasserian glycerol injection. Cerebrospinal fluid cultures grew G. haemolysans. Initial treatment with ampicillin and cefotaxime followed by benzylpenicillin was successful.

Carbon monoxide prevents apoptosis induced by uropathogenic Escherichia coli toxins

Urinary tract infections (UTIs) are often caused by Escherichia coli (E. coli). Previous studies have demonstrated that up-regulation of heme oxygenase-1 (HO-1) may trigger a survival mechanism against renal cell death induced by E. coli toxins. The present study analyses the role of carbon monoxide (CO), an end product of HO-1, in the survival mechanism. Moreover, we identified hemolysin as a putative pro-apoptotic toxin in the E. coli supernatant. Tubular cells were incubated with CO in the presence or absence of E. coli toxins. Uropathogenic or transformants of non-pathogenic strains expressing hemolysin were used. We found that the survival pathway during E. coli infection might be activated by HO-1-derived production of CO. The protection by CO was also associated with up-regulation of p21 protein expression. Furthermore, we found that in children with pyelonephritis, all the E. coli strains expressing hemolysin induced apoptosis. In E. coli strains not expressing hemolysin, only 45% of the strains could induce apoptosis. In conclusion, generation of CO elicited by HO-1 could promote survival signaling in renal cells. Hemolysin is one of the secreted toxins that are involved in inducing apoptosis during UTI.

Performance of Uricult Trio assessed by a comparison method and external control panels in primary healthcare

Using the comparison method, we have evaluated the technical performance of Uricult Trio® by culturing on Uricult Trio® and agar plates. Urine samples (477) from patients in primary healthcare were cultured in parallel in a microbiology laboratory. The result for Uricult Trio® evaluated using the comparison method was incorrect in 32% of the cultures. We also studied the performance of Uricult Trio® when used in primary healthcare by using external control panels. External control panels consisting of Uricult Trio®, inoculated with known concentrations of certain bacterial strains, were used to assess the performance of Uricult Trio® in primary healthcare during the period 1993-7. Aberrations in reports of concentration have ranged from 10% to 33%, failure in reporting of mixed culture from 0% to 91% and reporting of E. coli from 15% to 86%. There has been no sign of improvement over the years. The results indicate that Uricult Trio® is unsuitable for indications other than exclusion of urinary tract infection or diagnosis of urinary tract infection caused by E. coli. Further, there is need for quality assurance and training activities at primary healthcare laboratories, probably best carried out in collaboration with local clinical microbiology laboratories.

Difficulties for primary health care staff in interpreting bacterial findings on a device for simplified urinary culture.

The reliability of interpretations of findings from dip‐slide devices for culturing urine was investigated in a national Swedish external quality assessment (EQA) programme. Also investigated was the extent of improvement in the examination procedure achieved through personnel training programmes and information. According to Swedish national recommendations, dip‐slide should only be used in primary health care (PHC) in cases of uncomplicated urinary tract infection (UTI) in females of childbearing age. The recommendations also define six possible outcomes of a dip‐slide examination, outcomes that have formed the basis for the EQA programme since 2001. No improvement in ability to classify readings correctly into the six categories was noted for the period 2001 to 2006. Preparations containing ‘mixed flora’ presented participants with the greatest difficulty, with only 28 % correct reports. The EQA programme, with educational components and voluntary participation, has not improved quality. The disappointing results might be a reflection of the limited effort and resources allocated by clinical microbiology laboratories for training and for sustaining proficiency in the evaluation of dip‐slides. For these reasons, we cannot at present recommend the dip‐slide technique for use in PHC settings.

Terms used to describe urinary tract infections--the importance of conceptual clarification.

Inaccuracies in medical language are detrimental to communication and statistics in medicine, and thereby to clinical practice, medical science and public health. The purpose of this article is to explore inconsistencies in the use of some medical terms: urinary tract infection, bacteriuria and urethral syndrome. The investigated literature was collected from medical dictionaries, textbooks, and articles indexed in Medline®. We found various practices regarding how the medical terms should be defined, and had great difficulty in interpreting the status of the statements under the heading of ‘definition’. The lesson to be learned, besides a reminder of the importance of clearly defined medical concepts, is that it must be explicitly stated whether what is presented as a definition is to be considered as defining criterion, as recognising criterion or as characteristic of the disease entity.

Evaluation of two methods for improving quality of diagnosis of bacteriuria by culture in primary healthcare

This study evaluates the effect of training on the results from Uricult Trio® and an established urine culture when used at primary healthcare laboratories in two Swedish counties, Uppsala and Värmland. Urine cultures and dipslides, Uricult Trio®, performed at these laboratories were interpreted a second time at central laboratories. Interpretation errors at the primary healthcare laboratories were calculated. Primary healthcare laboratories also received external control panels with urine cultures and dipslides. There was one study period each year for 3 years in Uppsala and for 2 years in Värmland. A training programme was completed between study periods in Värmland. In Uppsala, primary healthcare laboratory results could be reviewed, as interpretations by the central laboratory were returned to them. The main outcome measures were the percentage of interpretation errors which, in the first study period, was 33-39%. This dropped to 15-19% in the second study period. In the results from the external control panels there were no striking differences between the studied areas and Sweden as a whole, except that Uppsala showed a better result in reporting E. coli and failed in 10% compared to Sweden 46%. A method for both quality assessment and education is to ask the primary healthcare laboratories to send cultures to the central laboratory for interpretation requesting their return to the primary healthcare laboratory with the interpretation from the central laboratory attached.

Building a concept system to structure the contents of a decision support system- a grounded theory study of concepts in the knowledge domain of urinary tract infection

In this study we present a concept system for the knowledge domain of urinary tract infections. The system was constructed using grounded theory methods, sampling from Swedish reference texts and patient records from consultations for urinary tract infections. The concept system is intended for use as an aid in the construction of a decision support system (DSS) for urinary tract infections, and as a search module in the mentioned DSS. In total 561 concepts were categorized in four major, and 58 subordinate categories. Relationships between the more important categories were developed, and the frequency of use of the most common concepts is presented. Using the presented categorical structure as domain model a prototype DSS for dipslide urine cultures has been developed.In this study we present a concept system for the knowledge domain of urinary tract infections. The system was constructed using grounded theory methods, sampling from Swedish reference texts and patient records from consultations for urinary tract infections. The concept system is intended for use as an aid in the construction of a decision support system (DSS) for urinary tract infections, and as a search module in the mentioned DSS. In total 561 concepts were categorized in four major, and 58 subordinate categories. Relationships between the more important categories were developed, and the frequency of use of the most common concepts is presented. Using the presented categorical structure as domain model a prototype DSS for dipslide urine cultures has been developed.

Using the MEDLINE® database to study the concept of urinary tract infections in different domains of medicine

As a way of exploring differences between medical domains regarding management of urinary tract infections, we investigated the MEDLINE® database for differences in indexing patterns. Further, our intention was to assess the MEDLINE® database as a source for studying medical domains. We examined the use of main headings, subheadings and the level of main headings in six medical domains that manage urinary tract infections. Many intuitive but also some counterintuitive results were found indicating that the MEDLINE® database is difficult to use for studying medical domains mainly due to unclear semantics both in the headings and the indexing process, which results in variability in indexing. This variability probably hides significant results. We also conclude that the differences found indicate that in addition to differences between domains, there are also large variations within domains.