Epidemiology of extended-spectrum β-lactamase-producing Escherichia coli in Sweden 2007-2011

Extended-spectrum β-lactamase (ESBL) -producing Enterobacteriaceae have been notifiable according to the Swedish Communicable Disease Act since 2007. A major increase in the number of cases has been observed, with 2099 cases in 2007 and 7225 cases in 2012. The majority of the isolates are Escherichia coli. Additionally, Swedish data on the prevalence of ESBL-producing invasive isolates of E. coli are available through EARS-Net, and through biannual point prevalence studies, where molecular characterization of isolates from the entire country is carried out. This paper describes major trends in the Swedish epidemiology of ESBL-producing E. coli in the period 2007-2012. Isolates from the point prevalence studies were subjected to antimicrobial susceptibility testing, ESBL genotyping, pulsed-field gel electrophoresis, multi-locus sequence typing and phylogenetic grouping with PCR. The distribution of sequence types, resistance genes and susceptibility levels were all stable over the three study periods. The dominating resistance gene conferring ESBL was blaCTX -M-15 , found in 54-58% of the isolates. ST131 represented 34-38% of the isolates. Other major sequence types were ST38, ST69, ST405, ST617 and ST648, each representing 2-6% of the isolates. Phylogenetic group B2 was the most common, and was observed in 41-47% of the isolates. However, among ST131 isolates the B2 phylogenetic group represented 90-98% of the isolates. The most important epidemiological difference seen over time was that the median age of infected women decreased from 62 to 52 years (p <0.0001) and infected men from 67 to 64 years. A potential explanation might be the shift towards a higher proportion of community-acquired infections in individuals lacking comorbidities.

Alarming spread of vancomycin resistant enterococci in Sweden since 2007

The total number of persons infected or colonised with vancomycin-resistant enterococci mandatorily reported to the Swedish Institute for Infectious Disease Control increased dramatically during 2007 and 2008. During a period of twenty months from 1 July 2007 to 28 February 2009, a total of 760 cases were reported compared with 194 cases reported during the entire period from 2000 to 2006. This rise was mainly attributed to a wide dissemination of vancomycin resistant enterococci which started in a number of hospitals in Stockholm in the autumn of 2007 and was followed by dissemination in various healthcare facilities (hospitals and homes for the elderly) in a further two Swedish counties in 2008. The majority of the cases (97%) were acquired in Sweden and among these, healthcare-acquired E. faecium vanB dominated (n=634). The majority of these isolates had identical or closely related pulsed-field gel electrophoresis patterns indicating clonal dissemination in the affected counties. The median minimum inhibitory concentration of vancomycin was 32 mg/L (ranging from 4 to >128 mg/L) and of teichoplanin 0.12 mg/L (ranging from 0.06 to 0.25 mg/L). Particular emphasis was placed on countermeasures such as screening, contact tracing, cleaning procedures, education in accurate use of infection control practices as well as increasing awareness of hygiene among patients and visitors. With these measures the dissemination rate decreased substantially, but new infections with the E. faecium vanB strain were still detected.

Emergence and spread of Chlamydia trachomatis variant, Sweden

A variant of Chlamydia trachomatis that had escaped detection by commonly used systems was discovered in Sweden in 2006. In a nationwide study, we found that it is now prevalent across Sweden, irrespective of the detection system used. Genetic analysis by multilocus sequence typing identified a predominant variant, suggesting recent emergence.

A new beclomethasone dipropionate multidose powder inhaler in the treatment of bronchial asthma

The clinical efficacy, tolerability and acceptability of a new multidose powder inhaler (MDPI) containing beclomethasone dipropionate (BDP) were compared with those of a BDP aerosol administered with a large volume spacer (MDI-spacer) among adult asthmatics currently receiving from 500 to 1,000 microgram/day of an inhaled corticosteroid. During the study, the dosage of BDP from both devices was 400 microgram twice daily. Ninety-one patients were randomized to the MDPI group and 42 to the MDI-spacer group. The trial was performed as an open, randomized, parallel group multicenter study. The duration of the treatment period was 12 weeks, and the study was preceded by a 2-week run-in period. During the run-in period, the mean morning peak expiratory flow (PEF) was 487 and 466 1/min in the MDPI and MDI-spacer groups, respectively. After the 12-week treatment, the morning PEF was 491 1/min in the MDPI group and 463 1/min in the MDI-spacer group. The evening values were 500 and 479 1/min during the run-in period and 496 and 476 1/min after the 12-week treatment, respectively. Asthma symptom scores and the use of rescue medication were low in both groups, indicating good efficacy of the preparations tested. The median dose of histamine required to decrease forced expiratory volume in 1 s by 15% increased during the study from 800 to 1,098 microgram in the MDPI group and from 795 to 960 microgram in the MDI-spacer group. The most frequent adverse events in both groups were hoarseness and sore throat. There were no statistically significant differences between the treatment groups in serum cortisol values or in the number of patients with thrush. Seventy-two percent of the patients regarded the MDPI easier to use while 95% considered it more portable. Over 80% of the patients felt that the MDPI was also easier to clean and as easy or easier to learn to use than the MDI-spacer. To conclude, the novel powder inhaler is well tolerated and at least equally effective as the conventional MDI-spacer combination in the treatment of asthma with BDP. However, in everyday use, patients clearly favored the powder inhaler.

Alpha-haemolysin of uropathogenic E. coli induces Ca2+ oscillations in renal epithelial cells

Pyelonephritis is one of the most common febrile diseases in children. If not treated appropriately, it causes irreversible renal damage and accounts for a large proportion of end stage renal failures. Renal scarring can occur in the absence of inflammatory cells, indicating that bacteria may have a direct signalling effect on renal cells. Intracellular calcium ([Ca2+]i) oscillations can protect cells from the cytotoxic effects of prolonged increases in intracellular calcium. However, no pathophysiologically relevant protein that induces such oscillations has been identified. Here we show that infection by uropathogenic Escherichia coli induces a constant, low-frequency oscillatory [Ca2+]i response in target primary rat renal epithelial cells induced by the secreted RTX (repeats-in-toxin) toxin alpha-haemolysin. The response depends on calcium influx through L-type calcium channels as well as from internal stores gated by inositol triphosphate. Internal calcium oscillations induced by alpha-haemolysin in a renal epithelial cell line stimulated production of cytokines interleukin (IL)-6 and IL-8. Our findings indicate a novel role for alpha-haemolysin in pyelonephritis: as an inducer of an oscillating second messenger response in target cells, which fine-tunes gene expression during the inflammatory response.

High pleural fluid hyaluronan concentrations in rheumatoid arthritis

Previous studies have shown that high pleural fluid (Pf) hyaluronan (HYA) concentrations may be due not only to malignant mesothelioma but also to inflammatory diseases. The objective of this study was to evaluate Pf-HYA in various nonmalignant inflammatory pleural disorders. A radiometric assay was used to determine HYA in Pf and serum (S) of 126 patients, 12 of whom had rheumatoid arthritis (RA), 22 tuberculosis, 22 pneumonia, 41 lung cancer, 10 malignant mesothelioma and 19 congestive heart failure. Pf-HYA values were correlated with values for Pf-tumour necrosis factor (TNF)-alpha and Pf-interleukin (IL)-1beta, as determined by radioimmunoassay. The highest median Pf-HYA (125.6 mg x L(-1), range 0.04-386.5 mg x L(-1)) occurred in patients with malignant mesothelioma. Among patients with nonmalignant inflammatory diseases, significantly higher median Pf-HYA were observed in those with rheumatoid arthritis (64.2 mg x L(-1), range 25.8-106.9 mg x L(-1)) than in those with tuberculosis (25.5 mg x L(-1), range 14.9-57.1 mg x L(-1), p<0.0005) or pneumonia (20.9 mg x L(-1), range 9.5-129.4 mg x L(-1), p<0.005). There was no correlation between Pf-HYA and S-HYA. Pf-HYA correlated positively with Pf-TNF-alpha (r=0.62) and Pf-IL-1beta (r=0.52). High pleural fluid hyaluronan occurs not only in malignant mesothelioma, but also in certain nonmalignant inflammatory diseases, especially rheumatoid arthritis. One explanation for the increase in pleural fluid hyaluronan may be local production of proinflammatory cytokines, such as tumour necrosis factor-alpha and interleukin-1beta.

Pleural fluid interferon-gamma and tumour necrosis factor-alpha in tuberculous and rheumatoid pleurisy

Tuberculous and rheumatoid pleural effusions show features suggesting a strong local cellular immune response. Pleural fluid (Pf) from patients with tuberculosis, rheumatoid arthritis (RA) and other diseases were compared with respect to interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha). Immunoassays were used to determine Pf-IFN-gamma and Pf-TNF-alpha in 102 patients, including 11 with RA, 31 with verified tuberculosis, 23 with suspected tuberculosis, 11 with pneumonia, 14 with lung cancer and 12 with congestive heart failure. Measurable Pf-IFN-gamma occurred exclusively in patients with verified (median 1.8 ng x mL-1; 95% confidence interval (95% CI) 0.63-4.0 ng x mL-1) or suspected (0.37 ng x mL-1; 95%CI 0-0.7 ng x mL-1) tuberculosis. The highest median Pf-IFN-gamma was observed in those patients who showed a positive pleural fluid culture for Mycobacterium tuberculosis. In pleural effusions due to other diseases, including RA, IFN-gamma was undetectable. The highest Pf-TNF-alpha occurred in verified tuberculosis (median 198 ng x L-1; 95% CI 169-222 ng x L-1) and RA (210 ng x L-1; 95% CI 147-231 ng x L-1). Pleural fluid interferon-gamma is a highly useful marker for diagnosing tuberculous pleurisy. Although tuberculous and rheumatoid pleural effusions share several biochemical features, they are strikingly different with respect to interferon-gamma.

Neurone-specific enolase levels in pleural effusions in patients with rheumatoid arthritis

BACKGROUND

High pleural fluid levels of neurone-specific enolase (NSE) have been reported, not only in patients with small cell lung cancer but also in those with chronic inflammatory diseases.

METHODS

NSE concentrations were determined in pleural fluid and serum from 342 patients with pleural effusions including 17 with rheumatoid arthritis.

RESULTS

The median NSE concentration in pleural fluid was higher in rheumatoid effusions than in any other condition studied. The median pleural fluid:serum NSE ratio was highest in patients with rheumatoid arthritis (11.6) and about unity in all other diseases including small cell lung cancer (0.9). In patients with rheumatoid arthritis pleural fluid concentrations of NSE correlated inversely with pleural fluid glucose concentrations and the pH of the pleural fluid.

CONCLUSIONS

A high pleural fluid:serum NSE ratio was found consistently in pleural effusions from patients with rheumatoid disease.

Pleural fluid beta-2-microglobulin and angiotensin-converting enzyme concentrations in rheumatoid arthritis and tuberculosis

Concentrations of beta 2-microglobulin (B2M) and angiotensin-converting enzyme (ACE) were measured in pleural fluid (Pf) and serum (S) of 364 patients with pleural effusions. Eleven patients had rheumatoid arthritis (RA), 36 verified tuberculosis (TB), 15 suspected TB, 120 cancer, 21 empyema, 34 pneumonia, 33 various defined diseases, 67 effusions of unknown aetiology and 27 congestive heart failure. The median concentrations of Pf-B2M and Pf-ACE were significantly higher in patients with RA than in patients with any other disease (p < 0.005). Tuberculous effusions contained higher Pf-ACE concentrations than any other type of non-rheumatoid effusion (p < 0.05). With sensitivities of 91%, the specificity of Pf-B2M and Pf-ACE for the diagnosis of RA was 86% and 55%, respectively. Local cellular immune events probably account for the abundance of B2M and ACE in rheumatoid and tuberculous pleural effusions. Pf-B2M and Pf-ACE determinations may aid in the differentiation of rheumatoid and tuberculous pleurisy from other types of pleural disease.

Pleural fluid soluble interleukin 2 receptor in rheumatoid arthritis and systemic lupus erythematosus

OBJECTIVE

To study local cellular immune reactions in the pleural fluid of patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

METHODS

Using an immunoenzymometric assay, the concentration of soluble interleukin 2 receptor (sIL-2R) was measured in the pleural fluid of 13 patients with RA, 6 patients with SLE and 72 patients with pleural effusions of other etiologies, including tuberculosis, cancer, pneumonia and congestive heart failure.

RESULTS

The mean pleural fluid sIL-2R concentration was significantly higher in patients with RA (593 pM, range 252-1558) than in patients with SLE (145 pM, range 94-236; p < 0.005), cancer (224 pM, range 98-521, p < 0.01), pneumonia (177 pM, range 60-343, p < 0.005) and congestive heart failure (139 pM, range 56-228, p < 0.005), but as high in patients with tuberculous pleurisy (mean 390 pM, range 151-512). The highest mean pleural fluid to serum sIL-2R ratios were observed in patients with RA and with tuberculosis.

CONCLUSION

Measurement of sIL-2R in pleural fluid is useful for the differentiation of pleural effusions in RA from those occurring in SLE. High levels of sIL-2R associated with a local T cell mediated immune reaction may serve an immunoregulatory purpose in rheumatoid pleurisy.