Steinar Skrede

Necrotizing soft tissue infections caused by Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis of groups C and G in western Norway

Streptococcus pyogenes (group A streptococcus, GAS) is a major cause of necrotizing soft tissue infection (NSTI). On rare occasions, other β-haemolytic streptococci may also cause NSTI, but the significance and nature of these infections has not been thoroughly investigated. In this study, clinical and molecular characteristics of NSTI caused by GAS and β-haemolytic Streptococcus dysgalactiae subsp. equisimilis of groups C and G (GCS/GGS) in western Norway during 2000-09 are presented. Clinical data were included retrospectively. The bacterial isolates were subsequently emm typed and screened for the presence of genes encoding streptococcal superantigens. Seventy cases were identified, corresponding to a mean annual incidence rate of 1.4 per 100 000. Sixty-one of the cases were associated with GAS, whereas GCS/GGS accounted for the remaining nine cases. The in-hospital case fatality rates of GAS and GCS/GGS disease were 11% and 33%, respectively. The GCS/GGS patients were older, had comorbidities more often and had anatomically more superficial disease than the GAS patients. High age and toxic shock syndrome were associated with mortality. The Laboratory Risk Indicator for Necrotizing Fasciitis laboratory score showed high values (≥6) in only 31 of 67 cases. Among the available 42 GAS isolates, the most predominant emm types were emm1, emm3 and emm4. The virulence gene profiles were strongly correlated to emm type. The number of superantigen genes was low in the four available GCS/GGS isolates. Our findings indicate a high frequency of streptococcal necrotizing fasciitis in our community. GCS/GGS infections contribute to the disease burden, but differ from GAS cases in frequency and predisposing factors.

Invasive group A, C and G streptococcal disease in western Norway: virulence gene profiles, clinical features and outcomes

Invasive group A streptococcal (iGAS) disease is endemic in Norway, but data on invasive group C and group G streptococcal (iGCS/GGS) disease are lacking. We investigated the characteristics of iGAS and iGCS/GGS infections in western Norway from March 2006 to February 2009. Clinical information was retrospectively obtained from medical records. GAS and GCS/GGS isolates were emm typed and screened for the presence of 11 superantigen (SAg) genes and the gene encoding streptococcal phospholipase A₂ (SlaA). GCS/GGS isolates were also subjected to PCR with primers targeting speG(dys) . Sixty iGAS and 50 iGCS/GGS cases were identified, corresponding to mean annual incidence rates of 5.0 per 100,000 and 4.1 per 100,000 inhabitants, respectively. Skin and soft tissue infections were the most frequent clinical manifestations of both iGAS and iGCS/GGS disease, and 14 iGAS patients (23%) developed necrotizing fasciitis. The 30-day case fatality rates of iGAS and iGCS/GGS disease were 10% and 2%, respectively. emm1, emm3 and emm28 accounted for 53% of the GAS isolates, and these types were associated with severe clinical outcome. SAg gene and SlaA profiles were conserved within most of the GAS emm types, although five profiles were obtained within isolates of emm28. stG643 was the most prevalent GCS/GGS emm type, and speG(dys) was identified in 73% of the GCS/GGS isolates. Neither GAS SAg genes nor SlaA were detected in GCS/GGS. Our findings indicate a considerable burden of both iGAS and iGCS/GGS disease and a high frequency of necrotizing fasciitis caused by GAS in our community.

Massive Parallel Sequencing Provides New Perspectives on Bacterial Brain Abscesses

ABSTRACT Rapid development within the field of massive parallel sequencing (MPS) is about to bring this technology within reach for diagnostic microbiology laboratories. We wanted to explore its potential for improving diagnosis and understanding of polymicrobial infections, using bacterial brain abscesses as an example. We conducted a prospective nationwide study on bacterial brain abscesses. Fifty-two surgical samples were included over a 2-year period. The samples were categorized as either spontaneous intracerebral, spontaneous subdural, or postoperative. Bacterial 16S rRNA genes were amplified directly from the specimens and sequenced using Ion Torrent technology, with an average of 500,000 reads per sample. The results were compared to those from culture- and Sanger sequencing-based diagnostics. Compared to culture, MPS allowed for triple the number of bacterial identifications. Aggregatibacter aphrophilus, Fusobacterium nucleatum, and Streptococcus intermedius or combinations of them were found in all spontaneous polymicrobial abscesses. F. nucleatum was systematically detected in samples with anaerobic flora. The increased detection rate for Actinomyces spp. and facultative Gram-negative rods further revealed several species associations. We suggest that A. aphrophilus, F. nucleatum, and S. intermedius are key pathogens for the establishment of spontaneous polymicrobial brain abscesses. In addition, F. nucleatum seems to be important for the development of anaerobic flora. MPS can accurately describe polymicrobial specimens when a sufficient number of reads is used to compensate for unequal species concentrations and principles are defined to discard contaminant bacterial DNA in the subsequent data analysis. This will contribute to our understanding of how different types of polymicrobial infections develop.

emm gene diversity, superantigen gene profiles and presence of SlaA among clinical isolates of group A, C and G streptococci from western Norway

In order to investigate molecular characteristics of beta-hemolytic streptococcal isolates from western Norway, we analysed the entire emm gene sequences, obtained superantigen gene profiles and determined the prevalence of the gene encoding streptococcal phospholipase A2 (SlaA) of 165 non-invasive and 34 contemporary invasive group A, C and G streptococci (GAS, GCS and GGS). Among the 25 GAS and 26 GCS/GGS emm subtypes identified, only emm3.1 was significantly associated with invasive disease. M protein size variation within GAS and GCS/GGS emm types was frequently identified. Two non-invasive and one invasive GGS possessed emm genes that translated to truncated M proteins as a result of frameshift mutations. Results suggestive of recombinations between emm or emm-like gene segments were found in isolates of emm4 and stG485 types. One non-invasive GGS possessed speC, speG, speH, speI and smeZ, and another non-invasive GGS harboured SlaA. speA and SlaA were over-represented among invasive GAS, probably because they were associated with emm3. speGdys was identified in 83% of invasive and 63% of non-invasive GCS/GGS and correlated with certain emm subtypes. Our results indicate the invasive potential of isolates belonging to emm3, and show substantial emm gene diversity and possible lateral gene transfers in our streptococcal population.

Etiology of cellulitis and clinical prediction of streptococcal disease: A prospective study

This prospective study of cellulitis identified β-hemolytic streptococci as the dominating cause in all investigated subgroups. Group C/G streptococci were more frequently detected than group A streptococci. No single clinical feature substantially increased the probability of confirmed streptococcal etiology.

Severe malaria and artesunate treatment, Norway.

To the Editor: Approximately 8,000 cases of imported falciparum malaria are reported in Europe each year (1). In a study from Belgium of 1,743 persons with fever acquired in the Tropics, only falciparum malaria resulted in deaths (2). Until recently, the standard treatment of severe malaria was intravenous quinine (3). Frequent adverse effects, however, and reports of limited clinical efficacy in some falciparum malaraia–endemic areas preclude its usefulness (4). In contrast, artesunate, a water-soluble artemisinin derivate extracted from the plant Artemesia annua (quinghao), is considered safe and highly efficacious (4,5). Artesunate has the advantage of rapidly killing malaria parasites only a few hours after invading the erythrocyte, and it also reduces cytoadherance (4). Resistance to artesunate at the Cambodia–Thailand border has been reported, but until now artesunate resistance has not been considered a problem in most malaria–endemic regions (5,6). On the basis of 6 randomized controlled trials comparing artesunate and quinine, a recent Cochrane review recommended artesunate as the first-line treatment in adults with severe malaria in such areas (7). Similar recommendations were issued by the World Health Organization (WHO) in 2006 (8). Also, the European surveillance network, TropNetEurope, and the Advisory Committee on Malaria Prevention in UK Travelers advocate artesunate as the first-line treatment for severe falciparum malaria in travelers (9,10). However, the manufacturers of intravenous (IV) artesunate have not achieved Good Manufacturing Practice certification; currently, the drug is not widely used outside Asia. In March 2008, an inquiry for patients treated with IV artesunate for severe falciparum malaria was mailed to all major departments of infectious diseases in Norway. All departments responded, and 9 patients treated from February 2006 to May 2008 were identified at 3 centers: 7 at Haukeland University Hospital in Bergen, 1 at Akershus University Hospital in Nordbyhagen, and 1 at Ulleval University Hospital in Oslo. Clinical and laboratory features were retrospectively obtained from the medical records. Artesunate was produced by Guilin Pharmaceutical, Guangxi, China, and provided from IDIS Pharmaceutical, Weybridge, United Kingdom. With the exception of 1 patient who had become infected while in Myanmar, all patients acquired falciparum malaria in West Africa (Table). Four patients were Norwegian tourists or businessmen; 4 patients were visiting friends and relatives and had lived in Norway for 2, 15, 20, and 40 years, respectively. One patient was a pregnant (third trimester) immigrant. None of the patients had used antimalarial chemoprophylaxis. The patients’ symptoms fulfilled up to 5 of the WHO criteria for severe malaria: 1 patient had cerebral malaria, 5 impaired consciousness, 5 jaundice, 2 shock, 2 renal failure, 2 hemoglobinuria, 1 hematemesis, and 8 hyperparasitemia (Table). The initial treatment consisted of IV artesunate plus doxycycline (n = 7), IV artesunate monotherapy (n = 1), or IV artesunate plus clindamycin (n = 1). The dosing of artesunate was 2.4 mg/kg at 0 h, 12 h, and 24 h and then daily thereafter. Patient 6 received a 1,200-mg loading dose of quinine before transfer to one of the study hospitals (Table). None of the patients needed exchange transfusions. No adverse effects were attributed to artesunate, and the pregnant patient delivered a healthy child at term. The parasitemia level fell below 1% in all patients within 1–2 days. Treatment was changed to oral antimalarial drugs (artemether–lumefantrine, mefloquine, proguanil–atovaquone, or quinine) within 2.1 days (mean); all patients recovered uneventfully and were discharged from the hospital within 4.2 days (mean) (Table). No episodes of recrudescence were documented posttreatment at 4 weeks follow-up; 7 patients had a negative malaria slide and 2 patients were not examined for parasites but had no clinical recrudescense at follow-up. Table Epidemiologic, clinical, and laboratory data from 9 patients with severe falciparum malaria treated with intravenous artesunate, Norway, 2006–2008* Our findings support those of several randomized controlled trials performed in Asia and indicate that therapy with IV artesunate is safe, induces rapid parasite clearing, and usually results in swift clinical cure. Blood exchange transfusion, a labor-intensive and potentially hazardous procedure, was initially considered for 2 of our patients but was deemed unnecessary because of the rapid improvement after artesunate treatment. Artemisinins have short half-lives, and there is an increased risk for recrudescence if used alone. We gave concurrent IV doxycycline or clindamycin to all but 1 of our patients; all patients were treated with an oral drug after IV artesunate, and recrudescence was not noted. A major obstacle for the use of IV artesunate is its poor availability outside Asia and the fact that its use is not approved in many countries. However, in the United States, artesunate for infusion may now be obtained as an investigational drug from the Centers for Disease Control and Prevention (www.cdc.gov/malaria/features/artesunate_now_available.htm), and in the European Union, artesunate recently received the Orphan Medicinal Drug Designation from the European Medicines Agency (www.emea.europa.eu/pdfs/human/comp/opinion/48693207en.pdf) and may be obtained from IDIS Pharma (www.idispharma.com). If falciparum malaria is acquired at the Cambodia–Thailand border region, artesunate resistance should be considered; except for this region, where mefloquine resistance also is a problem, artesunate is considered to be an efficacious drug with limited reports of resistance. In conclusion, the current case series suggests that IV artesunate is an efficacious and safe treatment option in travelers returning from West Africa with severe falciparum malaria.

Two Unusual Cases of Severe Soft Tissue Infection Caused by Streptococcus dysgalactiae subsp. equisimilis

ABSTRACT We present two cases of invasive infection caused by Streptococcus dysgalactiae subsp. equisimilis, one that showed rapidly developing necrotizing fasciitis in a previously healthy man and one that showed severe cellulitis and septic shock even though the bacterium possessed a mutated emm gene, predicted to encode a truncated M protein.

Molecular epidemiological investigation of an outbreak of invasive β‐haemolytic streptococcal infection in western Norway

During a decade-long, high endemic situation with severe group A streptococcal disease in western Norway, a cluster of 16 patients with invasive streptococcal disease was hospitalized during a period of 11 weeks. A study including clinical characteristics and molecular epidemiology of the outbreak was initiated. Relevant clinical information was obtained from the medical records of the patients. Nine of the 16 patients had soft tissue infection, and seven of these had streptococcal toxic shock syndrome (STSS). Mortality, both overall and among those with STSS, was 25%. Streptococcal isolates from these patients were characterized by serogrouping and emm sequence typing. The emm amplicons were further characterized by sequence analysis and restriction fragment length polymorphism (emm RFLP) analysis. The streptococci were identified as group A streptococcus (GAS) in 11 patients and group G streptococcus (GGS) in four patients. The patients with GGS infection were older than the patients with GAS infection, and all patients infected with GGS had predisposing comorbidities. Isolates from 13 patients were available for emm gene analysis and found to belong to nine different emm types. Similar differentiation was obtained with emm RFLP in GAS. Hence, the outbreak was polyclonal. Results suggestive of horizontal gene transfer and recombination between the emm genes of GAS, group C streptococcus and GGS were found in the isolates from seven patients. Such genetic recombination events suggest a possible role in pathogenesis.

Improved prognosis in Norwegian patients with glomerulonephritis associated with anti-neutrophil cytoplasmic antibodies

Background Glomerulonephritis associated with anti-neutrophil cytoplasmic antibodies (ANCA) is associated with increased mortality and a high risk of end-stage renal disease (ESRD). Here, we investigated whether the prognosis has improved over the last 25 years. Methods Patients were identified in the Norwegian Kidney Biopsy Registry. We included all patients with pauci-immune crescentic glomerulonephritis and a positive ANCA test from 1988 to 2012. Deaths and ESRD in the cohort were identified through record linkage with the Norwegian Population Registry (deaths) and the Norwegian Renal Registry (ESRD). Outcomes of patients diagnosed in 1988–2002 were compared with outcomes of patients diagnosed in 2003–12. Results A cohort of 455 patients with ANCA-associated glomerulonephritis was identified. The mean follow-up was 6.0 years (range, 0.0–23.4). During the study period, 165 (36%) patients died and 124 (27%) progressed to ESRD. Compared with patients diagnosed in 1988–2002, those diagnosed in 2003–12 had higher mean initial estimated glomerular filtration rates (37 versus 27 mL/min/1.73 m2) and lower risk of ESRD (1-year risk: 13 versus 19%; 10-year risk: 26 versus 37%). The composite endpoint, ESRD or death within 0–1 year after diagnosis, was reduced from 34 to 25%. In patients over 60 years old, 1-year mortality fell from 33 to 20%. Conclusions In Norwegian patients with ANCA-associated glomerulonephritis, prognosis was significantly better in 2003–12 compared with 1988–2002. This improvement was probably partly due to a shorter diagnostic delay, and better therapeutic management in older patients.

Salivary IgA from the sublingual compartment as a novel noninvasive proxy for intestinal immune induction

Whole-saliva IgA appears like an attractive noninvasive readout for intestinal immune induction after enteric infection or vaccination, but has failed to show consistent correlation with established invasive markers and IgA in feces or intestinal lavage. For reference, we measured antibodies in samples from 30 healthy volunteers who were orally infected with wild-type enterotoxigenic Escherichia coli. The response against these bacteria in serum, lavage, and lymphocyte supernatants (antibody-in-lymphocyte-supernatant, ALS) was compared with that in targeted parotid and sublingual/submandibular secretions. Strong correlation occurred between IgA antibody levels against the challenge bacteria in sublingual/submandibular secretions and in lavage (r=0.69, P<0.0001) and ALS (r=0.70, P<0.0001). In sublingual/submandibular secretions, 93% responded with more than a twofold increase in IgA antibodies against the challenge strain, whereas the corresponding response in parotid secretions was only 67% (P=0.039). With >twofold ALS as a reference, the sensitivity of a >twofold response for IgA in sublingual/submandibular secretion was 96%, whereas it was only 67% in the parotid fluid. To exclude that flow rate variations influenced the results, we used albumin as a marker. Our data suggested that IgA in sublingual/submandibular secretions, rather than whole saliva with its variable content of parotid fluid, is a preferential noninvasive proxy for intestinal immune induction.