Mycotic abdominal aortic aneurysm caused by Borrelia afzelii: a case report

Background

Inflammatory aneurysms and mycotic aneurysms make up a minority of abdominal aortic aneurysms. Mainly autoimmune mechanisms are proposed in the pathogenesis of inflammatory aneurysms, and it is not routine to check for infectious agents as disease culprits.

Case presentation

A 58-year-old European male with complaints of abdominal and back pain for 8 weeks was admitted after a semi-urgent computed tomography scan revealed an 85 mm inflammatory abdominal aortic aneurysm. The patient had normal vital signs, slightly elevated inflammatory markers, and mild anemia on admission. Clinical examination revealed a tender pulsating mass in his abdomen. His clinical condition was interpreted as impending rupture and urgent repair of the aneurysm was deemed necessary. Due to the patient’s relatively young age and aneurysm neck morphology, open aortic repair was preferred. Preoperatively, the aneurysm appeared inflamed, with fibrous wall thickening and perianeurysmal adhesions. Aneurysm wall biopsies were sent to histopathological and microbiological diagnostics. Routine cultures were negative, but 16S rRNA gene real-time polymerase chain reaction was positive and Borrelia afzelii was identified by DNA sequencing of the polymerase chain reaction product. B. afzelii was also identified by sequencing the polymerase chain reaction product of a Borrelia-specific groEL target. Immunoglobulin G and M anti-Borrelia antibodies were present on serological analysis. Histopathological analysis displayed loss of normal aortic wall structure and diffuse infiltration of lymphocytes and plasma cells. The patient had an uneventful recovery and was discharged after 1 week to a regional rehabilitation facility. Though the patient fares clinically well and inflammatory markers had normalized, antimicrobial treatment with doxycycline continues at 3 months follow-up due to remaining radiologic signs of inflammation.

Conclusions

Borrelia infection in the setting of acute aortic pathology is a rare entity. To our knowledge, this is the first case report to demonstrate a mycotic abdominal aortic aneurysm as a rare manifestation of Lyme disease. Aortic wall biopsies and real-time polymerase chain reaction analysis of the specimen were essential for accurate diagnosis. This finding may contribute to the understanding of the etiology of inflammatory aneurysmal disease and abdominal aneurysms in general.

Novel Peptides Targeting the β-Clamp Rapidly Kill Planktonic and Biofilm Staphylococcus epidermidis Both in vitro and in vivo

Antimicrobial resistance is an increasing threat to global health and challenges the way we treat infections. Peptides containing the PCNA interacting motif APIM (APIM-peptides) were recently shown to bind to the bacterial PCNA homolog, the beta (β)-clamp, and to have both antibacterial and anti-mutagenic activities. In this study we explore the antibacterial effects of these peptides on Staphylococcus epidermidis, a bacterial species commonly found in prosthetic joint infections (PJI). Drug-resistant bacterial isolates from PJIs often lead to difficult-to-treat chronic infections. We show that APIM-peptides have a rapid bactericidal effect which when used at sublethal levels also increase the efficacy of gentamicin. In addition, APIM-peptides reduce development and eliminate already existing S. epidermidis biofilm. To study the potential use of APIM-peptides to prevent PJI, we used an in vivo bone graft model in rats where APIM-peptide, gentamicin, or a combination of the two was added to cement. The bone grafts containing cement with the combination was more effective than cement containing only gentamicin, which is the current standard of care. In summary, these results suggest that APIM-peptides can be a promising new drug candidate for anti-infective implant materials to use in the fight against resistant bacteria and chronic PJI.

Highly variable effect of sonication to dislodge biofilm-embedded Staphylococcus epidermidis directly quantified by epifluorescence microscopy: an in vitro model study

BACKGROUND

In cases of prosthetic joint infections, culture of sonication fluid can supplement culture of harvested tissue samples for correct microbial diagnosis. However, discrepant results regarding the increased sensitivity of sonication have been reported in several studies. To what degree bacteria embedded in biofilm are dislodged during the sonication process has to our knowledge not been fully elucidated. In the present in vitro study, we have evaluated the effect of sonication as a method to dislodge biofilm by quantitative microscopy.

METHODS

We used a standard biofilm method to cover small steel plates with biofilm forming Staphylococcus epidermidis ATCC 35984 and carried out the sonication procedure according to clinical practice. By comparing area covered with biofilm before and after sonication with epifluorescence microscopy, the effect of sonication on biofilm removal was quantified. Two series of experiments were made, one with 24-h biofilm formation and another with 72-h biofilm formation. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to confirm whether bacteria were present after sonication. In addition, quantitative bacteriology of sonication fluid was performed.

RESULTS

Epifluorescence microscopy enabled visualization of biofilm before and after sonication. CLSM and SEM confirmed coccoid cells on the surface after sonication. Biofilm was dislodged in a highly variable manner.

CONCLUSION

There is an unexpected high variation seen in the ability of sonication to dislodge biofilm-embedded S. epidermidis in this in vitro model.

Establishment of an in vivo rat model for chronic musculoskeletal implant infection

Background

The aim of the study was to establish an experimental chronic musculoskeletal infection model in vivo characterized by (a) a small bacterial inoculum, (b) no general or local signs of infection, (c) several parallels (implants) in each animal and finally (d) a model that is technically easy to perform.

Methods

Bone xenografts with steel plates were implanted intramuscularly in rats. To the xenografts, different inocula of Staphylococcus aureus and two strains of Staphylococcus epidermidis were added. The animals were observed for different time periods before the removal of the xenografts. The xenografts and steel plates were subjected to quantitative bacterial culture after sonication. Additional steel plates were subjected to scanning electron microscopy (SEM) for visualization of biofilm formation.

Results

Inoculation of bone grafts with S. aureus did produce a pyogenic infection in all animals. A chronic infection was established in rats where the bone grafts were inoculated with S. epidermidis. A bacterial inoculum of 100 colony-forming units (CFU) of S. epidermidis was adequate as a minimum infective dose. During a period of up until 42 days, the animals infected with S. epidermidis had no general or local signs of infection. According to the results of the quantitative bacterial culture of sonicate fluid and SEM, a biofilm was developed on all implants.

Conclusion

In the present in vivo model, a very small bacterial inoculum succeeded in establishing a chronic musculoskeletal implant infection where a biofilm was formed on the implants. The experimental model is easy to perform and allows several implants in each animal. The model could be useful for the study of biofilm formation in vivo on different implants and different surfaces.

Investigation of an outbreak caused by antibiotic-susceptible Klebsiella oxytoca in a neonatal intensive care unit in Norway

AIM

Klebsiella spp. have been stated to be the most frequent cause of neonatal intensive care unit (NICU) outbreaks. We report an outbreak of Klebsiella oxytoca in a NICU at a tertiary care hospital in Norway between April 2016 and April 2017. This study describes the outbreak, infection control measures undertaken and the molecular methods developed.

METHODS

The outbreak prompted detailed epidemiological and microbial investigations, where whole-genome sequencing (WGS) was particularly useful for both genotyping and development of two new K. oxytoca-specific real-time PCR assays. Routine screening of patients, as well as sampling from numerous environmental sites, was performed during the outbreak. A bundle of infection control measures was instigated to control the outbreak, among them strict cohort isolation.

RESULTS

Five neonates had symptomatic infection, and 17 were found to be asymptomatically colonised. Infections varied in severity from conjunctivitis to a fatal case of pneumonia. A source of the outbreak could not be determined.

CONCLUSION

This report describes K. oxytoca as a significant pathogen in a NICU outbreak setting and highlights the importance of developing appropriate microbiological screening methods and implementing strict infection control measures to control the outbreak in a setting where the source could not be identified.

Rapid discrimination of Staphylococcus epidermidis genotypes in a routine clinical microbiological laboratory using single nucleotide polymorphisms in housekeeping genes

PURPOSE

Staphylococcus epidermidis colonies often display several morphologies and antimicrobial susceptibility patterns when cultured from device-related infections, and may represent one or multiple genotypes. Genotyping may be helpful in the clinical interpretation, but is time consuming and expensive. We wanted to establish a method for rapid discrimination of S. epidermidis genotypes for use in a routine microbiology laboratory.

METHODOLOGY

A real-time PCR targeting eight discriminatory class I or II single-nucleotide polymorphisms (SNPs) in six of the seven housekeeping genes was constructed. Post PCR, high-resolution melt (HRM) analysis using EvaGreen as fluorophore discriminated amplicons based on their percentage GC content.

RESULTS

In silico, 42 representative sequence types (STs), including all major MLST group and subgroup founders, were separated into 23 different cluster profiles with a Simpson's index of diversity of 0.97. By HRM-PCR, 11 commonly encountered hospital and outbreak STs were separated into eight HRM patterns.

CONCLUSION

This method can rapidly establish whether S. epidermidis strains belong to different genotypes. It can be used in patients with S. epidermidis infections, as an aid in outbreak investigations and to select strains for investigation with more discriminatory methods, saving workload and costs. Results may be obtained the same day as culture results. Its strength lies mainly in indicating differences, as some STs may have the same melt profile. Changes in S. epidermidis epidemiology may warrant alterations in the inclusion of SNPs. We believe this method can reduce the threshold for performing genotyping analysis on an increasingly important nosocomial pathogen.

Characterization of the virulence potential of Staphylococcus condimenti isolated from a patient with severe soft tissue infection

The coagulase-negative bacterium Staphylococcus condimenti and closely related species are commonly isolated from or found in starter cultures of fermented sausage as well as fish and soy sauces, and have traditionally been considered nonpathogenic. Recently, however, a case of catheter-related bacteraemia caused by S. condimenti was reported. In the present study we identified and characterized a strain of S. condimenti isolated from a patient with a severe soft tissue infection, comparing it to S. condimenti and S. carnosus type strains in order to elucidate the virulence potential of the clinical strain. Genome comparison showed high degree of conservation between the clinical strain and the type strain used in food industry, as well as with S. carnosus. The genome of the clinical S. condimenti strain contains few horizontally transferred regions and 37 putative virulence genes, including genes with similarity to leucocidin and genes involved in immune evasion, proinflammatory and cytolytic activity. However, it remains to be tested whether these putative virulence genes are expressed and functional. Although uncommon, S. condimenti may cause severe infection in previously healthy persons.

Fecal neutrophil gelatinase-associated lipocalin as a biomarker for inflammatory bowel disease

BACKGROUND AND AIM

Accurate, noninvasive biomarkers are needed to diagnose and monitor inflammatory bowel disease (IBD). Neutrophil gelatinase-associated lipocalin (NGAL), also known as lipocalin 2, is expressed in inflamed colonic epithelium and neutrophilic granulocytes. This study explores its properties as a biomarker in feces and plasma and, for the first time, compares fecal NGAL systematically with the existing fecal biomarker calprotectin.

METHODS

Neutrophil gelatinase-associated lipocalin was measured in feces from 73 patients with IBD, 21 patients with infectious enterocolitis, 21 patients with irritable bowel syndrome, and 23 healthy subjects using ELISA. The results were correlated to calprotectin, clinical score, endoscopic score, and high-sensitive C-reactive protein. Plasma from 119 patients with IBD and 28 healthy controls was analyzed for NGAL.

RESULTS

Fecal NGAL levels (median and interquartile range) were significantly elevated in active ulcerative colitis (UC) 6.05 (3.6-15.1) mg/kg and Crohn's disease (CD) 4.9 (1.5-7.7) mg/kg, compared with patients with inactive UC 1.3 (0.4-2.6) mg/kg, inactive CD 1.5 (0.5-1.7) mg/kg, irritable bowel syndrome 0.4 (0.2-0.6) mg/kg, and healthy controls (HC) 0.3 (0.1-0.4) mg/kg. Patients with infectious enterocolitis had significantly higher fecal-NGAL levels, 2.7 (1.4-5.6) mg/kg than HC. Sensitivity and specificity was 94.7% and 95.7%, respectively, for distinguishing between active IBD and HC. Stability of NGAL in stool was excellent for 7 days in room temperature. Plasma NGAL was significantly elevated in UC and CD compared with HC.

CONCLUSIONS

Fecal NGAL is a promising biomarker for IBD. As existing biomarkers are expressed mainly in granulocytes, NGAL's epithelial localization may give supplementary diagnostic information.

Development of a rapid and simplified protocol for direct bacterial identification from positive blood cultures by using matrix assisted laser desorption ionization time-of- flight mass spectrometry

BACKGROUND

Bloodstream infections represent serious conditions carrying a high mortality and morbidity rate. Rapid identification of microorganisms and prompt institution of adequate antimicrobial therapy is of utmost importance for a successful outcome. Aiming at the development of a rapid, simplified and efficient protocol, we developed and compared two in-house preparatory methods for the direct identification of bacteria from positive blood culture flasks (BD BACTEC FX system) by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF MS). Both methods employed saponin and distilled water for erythrocyte lysis. In method A the cellular pellet was overlaid with formic acid on the MALDI TOF target plate for protein extraction, whereas in method B the pellet was exposed to formic acid followed by acetonitrile prior to placing on the target plate.

RESULTS

Best results were obtained by method A. Direct identification was achieved for 81.9 % and 65.8 % (50.3 % and 26.2 % with scores >2.0) of organisms by method A and method B, respectively. Overall concordance with final identification was 100 % to genus and 97.9 % to species level. By applying a lower cut-off score value, the levels of identification obtained by method A and method B increased to 89.3 % and 77.8 % of organisms (81.9 % and 65.8 % identified with scores >1.7), respectively. Using the lowered score criteria, concordance with final results was obtained for 99.3 % of genus and 96.6 % of species identifications.

CONCLUSION

The reliability of results, rapid performance (approximately 25 min) and applicability of in-house method A have contributed to implementation of this robust and cost-effective method in our laboratory.

Phylogeographical pattern of Francisella tularensis in a nationwide outbreak of tularaemia in Norway, 2011

In 2011, a nationwide outbreak of tularaemia occurred in Norway with 180 recorded cases. It was associated with the largest peak in lemming density seen in 40 years. Francisella tularensis was isolated from 18 patients. To study the geographical distribution of F. tularensis genotypes in Norway and correlate genotype with epidemiology and clinical presentation, we performed whole genome sequencing of patient isolates. All 18 genomes from the outbreak carried genetic signatures of F. tularensis subsp. holarctica and were assigned to genetic clades using canonical single nucleotide polymorphisms. Ten isolates were assigned to major genetic clade B.6 (subclade B.7), seven to clade B.12, and one to clade B.4. The B.6 subclade B.7 was most common in southern and central Norway, while clade B.12 was evenly distributed between the southern, central and northern parts of the country. There was no association between genotype and clinical presentation of tularaemia, time of year or specimen type. We found extensive sequence similarity with F. tularensis subsp. holarctica genomes from high-endemic tularaemia areas in Sweden. Finding nearly identical genomes across large geographical distances in Norway and Sweden imply a life cycle of the bacterium without replication between the outbreaks and raise new questions about long-range migration mechanisms.

Phylogeographical pattern of Francisella tularensis in a nationwide outbreak of tularaemia in Norway, 2011

In 2011, a nationwide outbreak of tularaemia occurred in Norway with 180 recorded cases. It was associated with the largest peak in lemming density seen in 40 years. Francisella tularensis was isolated from 18 patients. To study the geographical distribution of F.tularensis genotypes in Norway and correlate genotype with epidemiology and clinical presentation,we performed whole genome sequencing of patient isolates. All 18 genomes from the outbreak carried genetic signatures of F. tularensis subsp. holarctica and were assigned to genetic clades using canonical single nucleotide polymorphisms. Ten isolates were assigned to major genetic clade B.6 (subclade B.7),seven to clade B.12, and one to clade B.4. The B.6 subclade B.7 was most common in southern and central Norway, while clade B.12 was evenly distributed between the southern, central and northern parts of the country. There was no association between genotype and clinical presentation of tularaemia, time of year or specimen type. We found extensive sequence similarity with F. tularensis subsp. holarctica genomes from high-endemic tularaemia areas in Sweden.Finding nearly identical genomes across large geographical distances in Norway and Sweden imply a life cycle of the bacterium without replication between the outbreaks and raise new questions about long-range migration mechanisms.

Comparative genomics to delineate pathogenic potential in non-O157 Shiga toxin-producing Escherichia coli (STEC) from patients with and without haemolytic uremic syndrome (HUS) in Norway

Shiga toxin-producing Escherichia coli (STEC) cause infections in humans ranging from asymptomatic carriage to bloody diarrhoea and haemolytic uremic syndrome (HUS). Here we present whole genome comparison of Norwegian non-O157 STEC strains with the aim to distinguish between strains with the potential to cause HUS and less virulent strains. Whole genome sequencing and comparisons were performed across 95 non-O157 STEC strains. Twenty-three of these were classified as HUS-associated, including strains from patients with HUS (n = 19) and persons with an epidemiological link to a HUS-case (n = 4). Genomic comparison revealed considerable heterogeneity in gene content across the 95 STEC strains. A clear difference in gene profile was observed between strains with and without the Locus of Enterocyte Effacement (LEE) pathogenicity island. Phylogenetic analysis of the core genome showed high degree of diversity among the STEC strains, but all HUS-associated STEC strains were distributed in two distinct clusters within phylogroup B1. However, non-HUS strains were also found in these clusters. A number of accessory genes were found to be significantly overrepresented among HUS-associated STEC, but none of them were unique to this group of strains, suggesting that different sets of genes may contribute to the pathogenic potential in different phylogenetic STEC lineages. In this study we were not able to clearly distinguish between HUS-associated and non-HUS non-O157 STEC by extensive genome comparisons. Our results indicate that STECs from different phylogenetic backgrounds have independently acquired virulence genes that determine pathogenic potential, and that the content of such genes is overlapping between HUS-associated and non-HUS strains.

Imported toxigenic cutaneous diphtheria in a young male returning from Mozambique to Norway, March 2014

In March 2014 a 20-year-old man was diagnosed with cutaneous diphtheria at St. Olavs University Hospital in Trondheim, Norway on his return from Africa. The man had been in Mozambique since autumn 2013 and had experienced persistent skin ulcer infections. His was in good general health. Toxin-producing Corynebacterium diphtheriae was grown from a wound specimen. He had completed the national childhood vaccination programme and received a diphtheria vaccine booster dose in 2005. Screening of close contacts revealed an asymptomatic person colonised with non-toxigenic C. diphtheriae.

The gastrin receptor antagonist netazepide (YF476) prevents oxyntic mucosal inflammation induced by Helicobacter pylori infection in Mongolian gerbils

OBJECTIVE

Long-term Helicobacter pylori infection causes gastritis leading to hypergastrinemia and predisposes to gastric cancer. Our aim was to assess the role of gastrin in oxyntic mucosal inflammation in H. pylori-infected Mongolian gerbils by means of the gastrin receptor antagonist netazepide (YF476).

DESIGN

We studied 60 gerbils for 18 months and left five animals uninfected (control group), inoculated 55 with H. pylori, and treated 28 of the infected animals with netazepide (Hp+YF476 group). Twenty-seven infected animals were given no treatment (Hp group). We measured plasma gastrin and intraluminal pH. H. pylori detection and histologic evaluations of the stomach were carried out.

RESULTS

All 55 inoculated animals were H. pylori positive at termination. Eighteen animals in the Hp group had gastritis. There was a threefold increase in mucosal thickness in the Hp group compared to the Hp+YF476 group, and a threefold increase in oxyntic neuroendocrine cells in the Hp group compared to the Hp+YF476 group (p < .05). All animals in the Hp+YF476 group had macro- and microscopically normal findings in the stomach. Plasma gastrin was higher in the Hp group than in the control group (172 ± 16 pmol/L vs 124 ± 5 pmol/L, p < .05) and highest in the Hp+YF476 group (530 ± 36 pmol/L). Intraluminal pH was higher in the Hp group than in the Hp+YF476 group (2.51 vs 2.30, p < .05).

CONCLUSION

The gastrin antagonist netazepide prevents H. pylori-induced gastritis in Mongolian gerbils. Thus, gastrin has a key role in the inflammatory reaction of the gastric mucosa to H. pylori infection in this species.

Multiple-locus variant-repeat assay (MLVA) is a useful tool for molecular epidemiologic analysis of Streptococcus agalactiae strains causing bovine mastitis

Group B streptococci (GBS) were considered a major cause of mastitis in cattle until preventive measures succeeded in controlling the disease in the 1970s and 1980s. During the last 5-6 years an increasing number of cases have been observed in some Scandinavian countries. A total of 187 GBS isolates from mastitis cases were collected from 119 animals in 34 Norwegian farms in the period from April 2007 to November 2010. 133 (71%) of the isolates were from farms with automated milking systems. The strains underwent typing of capsular polysaccharides (CPS) and surface proteins, and were analyzed by multi-locus variable repeat assay (MLVA) to investigate the epidemiological relationship of strains within and between farms. The GBS strains were differentiated into 12 types by CPS and surface protein analysis, with CPS types V (54%) and IV (34%) predominating. MLVA was superior to CPS and protein typing for strain differentiation, resolving the 187 strains into 37 types. In 29 of 34 farms all GBS strains had identical MLVA profiles specific for each farm. However, in one farm represented with 48 isolates, four MLVA variants with differences in one repeat locus were observed during the almost 3-year long collection period. Similar variations were observed at four other farms. This might reflect the stability of repeat loci under in vivo conditions. Farms with automated milking systems were overrepresented in this material. In conclusion, the five-loci MLVA allowed rapid high-resolution genotyping of the bovine GBS strains within and between farms.

No increase in headache after previous intracranial infections: a historical cohort study (HUNT)

BACKGROUND AND PURPOSE

Despite the absence of robust scientific evidence, it is today generally accepted that the acute headache typical for intracranial infections can develop into permanent headache complaints. This widespread concept was explored in the first, large, longitudinal, population-based study.

METHODS

Data on confirmed exposure to intracranial infections amongst all adult inhabitants in a geographical area during a 20-year period were assembled from hospital records. Surviving individuals were later invited to the third Nord-Trøndelag Health Survey (HUNT 3), where 39,690 (42%) of 94,194 invited inhabitants aged ≥20 years responded to a validated headache questionnaire. Using logistic regression, the 1-year prevalence of headache and its subtypes according to the diagnostic criteria of the International Headache Society was assessed and compared between those with and without previous confirmed intracranial infection. Age and sex were used as covariates.

RESULTS

Overall, 43 participants were identified with earlier intracranial infection, whereof three had more than one infection: bacterial meningitis (n=19), lymphocytic meningitis (n=18), encephalitis (n=9), and brain abscess (n=1).The mean interval from infection to participation in HUNT 3 was 11.2 (range 1.5-19.7) years. There was no significant increase in the prevalence of headache (OR 1.10, 95% CI 0.58-2.07), its subtypes (migraine, or tension-type headache), or chronic daily headache (OR 1.85, 95% CI 0.45-7.68) amongst participants with previous intracranial infection compared with the surrounding population.

CONCLUSIONS

This study challenges the existence of chronic post-bacterial meningitis headache and does not indicate the presence of other long-term headaches induced by intracranial infection.

Outbreak of tularaemia in central Norway, January to March 2011

From January to March 2011, 39 cases of tularaemia were diagnosed in three counties in central Norway: 21 cases of oropharyngeal type, 10 cases of glandular/ulceroglandular type, two of respiratory and two of typhoid type. Three cases were asymptomatic and clinical information was unavailable for one case. The mean age was 40.3 years (range 2-89 years). Thirty-four reported use of drinking water from private wells. An increased rodent (lemming) population and snow melting may have led to contamination of the wells with infected rodents or rodent excreta.

Outbreak of tularaemia in central Norway, January to March 2011

From January to March 2011, 39 cases of tularaemia were diagnosed in three counties in central Norway: 21 cases of oropharyngeal type, 10 cases of glandular/ulceroglandular type, two of respiratory and two of typhoid type. Three cases were asymptomatic and clinical information was unavailable for one case. The mean age was 40.3 years (range 2-89 years). Thirty-four reported use of drinking water from private wells. An increased rodent (lemming) population and snow melting may have led to contamination of the wells with infected rodents or rodent excreta.

Susceptibility to quinupristin-dalfopristin and linezolid in 839 clinical isolates of gram-positive cocci from Norway

A total of 839 clinical isolates of Gram-positive cocci from Norway including Staphylococcus aureus (n = 214), coagulase negative Staphylococcus spp. (n = 100), Streptococcus pyogenes (n = 99), Streptococcus agalactiae (n = 80), Streptococcus pneumoniae (n = 127), Streptococcus spp. viridans group (n = 70), Enterococcus faecalis (n = 75), and Enterococcus faecium (n = 74), were tested by E-test for susceptibility to a range of antimicrobials including the novel antibiotics quinupristin-dalfopristin and linezolid. Subgroups of oxacillin resistant S. aureus and coagulase negative Staphylococcus spp., penicillin non-susceptible S. pneumoniae and vancomycin resistant Enterococcus spp. were specifically included as they are the intended targets for these new drugs. All isolates were susceptible to linezolid (MIC5o and MIC9o 0.25-2.0 mg/l, MIC range 0.12-2 mg/l). Staphylococcal and streptococcal isolates were also susceptible to quinupristin-dalfopristin except for some intermediately susceptible viridans group isolates (MIC54, and MIC90 0.25-2 mg/l, MIC range 0.125-2 mg/l). Enterococcus faecium (MIC90 = 4.0 mg/l) and Enterococcus faecalis (MIC50 = 8.0 mg/l, MIC90 > or = 32 mg/l) were less susceptible to this substance. There was no linkage between reduced susceptibility to linezolid or quinupristin-dalfopristin and resistance to other classes of antimicrobials. The study demonstrated a high prevalence of in vitro susceptibility to linezolid and quinupristin-dalfopristin, which is necessary for their use in the treatment of infections with resistant Gram-positive pathogens. The results were used to evaluate the appropriateness of breakpoints and to define a baseline for monitoring possible future emergence of resistance to quinupristin-dalfopristin and linezolid in Norway.

High local concentrations without systemic adverse effects after impaction of netilmicin-impregnated bone

BACKGROUND

When cancellous bone is impregnated with antibiotics the subsequent release of antibiotics from the bone shows a high early release. Hence, impaction of large amounts of netilmicin-impregnated bone may cause toxic netilmicin values in serum.

PATIENTS AND METHODS

We studied kidney and otovestibular function after impacting 50 g of netilmicin-impregnated cancellous bone during revision hip or knee arthroplasty in 20 patients. The bone was impacted in the acetabulum (n = 8), proximal femur (n = 9) and distal femur/proximal tibia (n = 3). Serum creatinine concentration was measured and audiometry was performed before and after the operation. Netilmicin concentrations in serum, joint fluid, and in urine were recorded postoperatively at regular intervals. We analyzed pharmacokinetics in two study groups receiving bone impregnated with netilmicin (50 mL), at either 50 mg netilmicin/mL (group I) or 100 mg netilmicin/mL (group II).

RESULTS

Neither netilmicin-induced renal toxicity, nor otovestibular toxicity was registered. Peak serum netilmicin values in group I and group II were 0.9 (0.5-1.3) mg/L and 1.8 (0.6-4.0) mg/L, respectively (p = 0.04). Peak netilmicin concentrations in wound drainage fluid in group I and group II were 237 (9-647) mg/L and 561 (196-1132) mg/L, respectively (p = 0.01). In both groups, netilmicin was recovered in urine samples for approximately 4 weeks.

INTERPRETATION

50 grams of cancellous bone impregnated with 100 mg/mL netilmicin solution was impacted in the hip or knee joint with no adverse effects. Extremely high local concentrations of netilmicin in joint fluid were recorded postoperatively. The use of antibioitic-impregnated cancellous could be an option when performing revision of hip and knee prostheses.

Identification of surface proteins of group B streptococci: serotyping versus genotyping

We compared serotyping to genotyping of group B streptococcal (GBS) surface proteins in 147 Australasian isolates. Results were concordant for the two methods in 73.8% of 122 isolates, discordant for three and partially discordant for 29 isolates. For the purpose of epidemiological typing of GBS, genotyping is superior to serotyping.

Molecular and phenotypic characterization of invasive group B streptococcus strains from infants in Norway 2006-2007

Multilocus sequence typing of an almost complete collection of invasive group B streptococcus (GBS) strains from infants in Norway, conducted in 2006-2007, revealed 27 sequence types (ST), of which 23 clustered into five clonal complexes. The case fatality rate of invasive GBS disease in infants was 16/98 (16.3%). Type V strains were predominant among strains resistant to erythromycin and clindamycin (11/18; 61.1%). All type V strains from fatal cases (5/16) were ST1, resistant to erythromycin and clindamycin, and belonged to three pulsed-field gel electrophoresis-clusters. Further analysis of virulence characteristics of these apparently highly virulent subtypes of type V, ST1 GBS strains is warranted.

Sonication is superior to scraping for retrieval of bacteria in biofilm on titanium and steel surfaces in vitro

BACKGROUND AND PURPOSE

Low-virulence implant infections are characterized by bacterial colonization of the implant with subsequent biofilm formation. In these cases, soft tissue biopsies often prove to be culture negative. Consequently, detachment of the causative adherent bacteria is crucial for correct microbiological diagnosis. Using an in vitro model, we compared 4 methods of biofilm sampling from metal surfaces.

METHODS

Discs of titanium and steel were incubated in the presence of Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, and Propionibacterium acnes in Mueller Hinton broth. Non-adherent bacteria were removed by repeated rinsing of the discs. 10 parallels of each disc were subjected to 1 of 4 methods for bacterial recovery: (A) sonication of the discs, (B) scraping of the discs using surgical blades followed by streaking of the blades onto agar plates, (C) scraping of the discs followed by vortex mixing of the surgical blades, and (D) scraping of the discs followed by sonication of the surgical blades. Quantitative bacterial cultures were performed for each sampling method.

RESULTS

With the exception of S. epidermidis on steel, sonication efficiently and reliably dislodged biofilm bacteria. The scraping methods employed did not detach bacteria embedded in biofilm.

INTERPRETATION

Scraping of metal surfaces is not an adequate method for sampling of biofilm bacteria in vitro.

Invasive group B streptococcus (GBS) disease in Norway 1996-2006

The aim of this study was to survey the occurrence of invasive group B streptococcus (GBS) disease in Norway and detect possible trends in characteristics of invasive GBS strains from 1996 to 2006. Data from national monitoring systems for infectious diseases in Norway were analysed. Of 638,452 live births in the period, 434 cases of invasive GBS disease in infants were reported. In adults and children older than 1 year of age, 969 cases were reported. The incidence of invasive GBS disease increased significantly in the elderly, while the incidence of neonatal early-onset disease was stable with 0.46 cases per 1,000 live births. The incidence of late-onset disease increased in 2005 and 2006. The lethality of GBS in infants increased from an average of 6.5% in 1996-2005 to 20% in 2006. Serotypes III and V were predominant in 839 invasive GBS strains characterized-type III in infants and type V in the elderly. The distribution of serotypes did not change throughout the period. The distribution of detected surface proteins was stable from 1996 to 2005, but the detection rates in types III and V were low. Molecular methods for GBS typing introduced in 2006 made characterization of nearly all strains possible and appear more applicable to epidemiological studies of GBS than conventional methods. Resistance to erythromycin and clindamycin increased significantly in 2006. The increased incidence in the elderly, the increased lethality in infants in 2006, and the increased resistance to erythromycin and clindamycin the same year might indicate changing characteristics of invasive GBS strains.

[Whipple's disease]

BACKGROUND

Whipple's disease is a rare infectious disease. This review describes the clinical picture, diagnostic aspects and treatment options.

MATERIAL AND METHODS

Based on a clinical case, a literature study was performed by searching PubMed (unlimited) with the words "whipples disease" combined with " TROPHERYMA WHIPPELII: " (118 hits) and " TROPHERYMA WHIPPLEI:" (65 hits). Titles and abstracts were used to identify other relevant articles.

RESULTS AND INTERPRETATION

Whipple's disease may affect several organ systems and thus causes a wide range of symptoms. The most common ones are weight loss, abdominal pain, diarrhoea and arthralgia. The diagnosis is based on PAS-POSITIVE MATERIAL: in duodenal biopsies and identification of gene fragments from the bacterium TROPHERYMA WHIPPLEI:. Presence of the bacterium may be confirmed by sensitive polymerase chain reaction assays. Left without treatment the disease may be lethal. Proper antibiotic treatment is imperative to heal the disease.

Characterisation of invasive group B streptococci based on investigation of surface proteins and genes encoding surface proteins

The joint distributions of the six genes bca, bac, epsilon/alp1, alp2, alp3 and rib (encoding alpha-C-protein, beta-C-protein, epsilon/Alp1, Alp2, Alp3, and Rib, respectively) and the proteins alpha-C-protein, beta-C-protein and Rib were investigated in invasive isolates of group B streptococcus (GBS). In total, 297 invasive isolates (123 from neonates, 174 from adults) from south-west Sweden were collected during a 13-year period. Genes were detected using multiplex and specific PCRs, and expression of the surface proteins was demonstrated using monoclonal antibodies. The genes studied were found alone or in combinations in 294 (99%) of the invasive isolates. The most common genes were rib (n = 127 isolates, 43%), alp3 (n = 78, 26%) and epsilon/alp1 (n = 42, 14%). The bac gene was never found alone, but was found in combination with one other gene in 36 isolates. The surface proteins studied were detected alone or in combinations in 152 (51%) isolates, with the most common being Rib (n = 80, 27%), alpha-C-protein (n = 68, 23%) and beta-C-protein (n = 24, 8%). Several genes were associated significantly with particular serotypes (e.g., epsilon/alp1 with serotype Ia; bca and bac with serotypes Ib and II; rib with serotype III; alp3 with serotype V). Overall, it was concluded that demonstration of different genes and surface proteins of GBS strains can be useful in epidemiological studies and in formulation of vaccines, but disappointingly, no single gene or surface protein included in the study was sufficiently common for it to be considered as the basis for a successful GBS vaccine.

Photoreactivity of biologically active compounds. XVIII. Photostability of ofloxacin in the solid state and in a tablet formulation

The photostability of ofloxacin in the solid state has been investigated. The change in colour of uncoated and film coated ofloxacin tablets and compressed ofloxacin was studied as a function of irradiance level and total exposure energy. The degradation of ofloxacin in the various preparations was quantified by HPLC and the antimicrobial activity was determined for selected tablets. The structure of two main degradation products from ofloxacin in the solid state has been postulated from LC-MS analysis. Both products have an absorption cut-off below 400 nm and cannot explain the observed change in tablet colour. There was no apparent relationship between the change in colour and the loss of active substance or antibacterial activity for the preparations investigated. The change in colour was easily detectable at rather low exposure levels. Apparently, there was a difference in light sensitivity between the two film-coated tablet batches investigated. The results obtained were partly dependent on the conditions within the radiation chamber (e.g., exposure time and irradiance level), which emphasizes the importance of testing the samples under various conditions unless the results are unequivocal. The tablets were sensitive to visible light although ofloxacin only has a neglectible absorption above 400 nm. The film coated ofloxacin tablets did, however, absorb above 400 nm with a cut-off at approximately 520 nm. A change in tablet coating to include a component that filters visible light in addition to UV radiation might provide a solution to the discolouration problem and prevent batch to batch variations with respect to light sensitivity.

Identification of virulence genes linked with diarrhea due to atypical enteropathogenic Escherichia coli by DNA microarray analysis and PCR

The role of atypical enteropathogenic Escherichia coli (EPEC) in childhood diarrhea is controversial. The aim of the present study was to search for genes linked with diarrhea in atypical EPEC strains from a case-control study among Norwegian children. Using DNA microarray analysis, genomic DNAs from strains isolated from children with (n = 37) and without (n = 20) diarrhea were hybridized against 242 different oligonucleotide probes specific for 182 virulence genes or markers from all known E. coli pathotypes. PCR was performed to test the strains for seven putative virulence genes not included in the microarray panel. The OI-122 gene efa1/lifA was the gene with the strongest statistical association with diarrhea (P = 0.0008). Other OI-122 genes (set/ent, nleB, and nleE) and genes with other locations (lpfA, paa, ehxA, and ureD) were also associated with diarrheal disease. The phylogenetic marker gene yjaA was negatively associated with diarrhea (P = 0.0004). Atypical EPEC strains could be classified in two main virulence groups based on their content of OI-122, lpfA, and yjaA genes. Among children with diarrhea, atypical EPEC isolates belonging to virulence group I (OI-122 and lpfA positive, yjaA negative) were the most common, while the majority of isolates from healthy children were classified as virulence group II strains (OI-122 negative, lpfA and yjaA positive; P < 0.001). In conclusion, using DNA microarray analysis to determine the virulence gene profile of atypical EPEC isolates, several genes were found to be significantly associated with diarrhea. Based on their composition of virulence genes, the majority of strains could be classified in two virulence groups, of which one was seen mainly in children with diarrhea.

Identification and differentiation of Legionella pneumophila and Legionella spp. with real-time PCR targeting the 16S rRNA gene and species identification by mip sequencing

Fluorescent resonance energy transfer probes targeting the 16S rRNA gene were constructed for a sensitive and specific real-time PCR for identification and differentiation of Legionella pneumophila from other Legionella spp. For identification of non-L. pneumophila spp. by direct amplicon sequencing, two conventional PCR assays targeting the mip gene were established.

Comparison of in vitro and in vivo complement activation by metal and bioabsorbable screws used in anterior cruciate ligament reconstruction

PURPOSE

The purpose of the study was to evaluate the biocompatibility of polylactide (PLLA) screws in comparison with standard metal screws for fixation of the patellar tendon graft in human anterior cruciate ligament (ACL) reconstruction.

METHODS

A total of 41 patients (22 women and 19 men) were prospectively randomized for the use of metal interference screws (20 patients) or biologically resorbable PLLA screws from Linvatec, Largo, FL (21 patients). Average age at the time of surgery was 26 years (15 to 51 y). Synovial fluid and plasma were collected preoperatively and after 6 weeks in both groups. Plasma was analyzed for C5a and synovial fluid, as well as for terminal SC5b-9 complement complex (TCC) and interleukin (IL)-8. At 1 year after surgery, serum was incubated with metal, PLLA, and no screws; this was followed by analysis of C5a after 1 and 6 hours of incubation. Inflammatory mediators were measured through enzyme-linked immunosorbent assay (ELISA).

RESULTS

In the BioScrew group, 4 patient samples showed high C5a concentration in synovial fluid after 6 weeks, but no statistically significant difference was observed between the 2 groups (P = .11). One patient in the BioScrew group had a high TCC value after 6 weeks, but no statistically significant difference was seen between the 2 groups (P = .20). In the in vitro study, no increased C5a generation was observed in sera incubated with a BioScrew or a metal screw compared with controls.

CONCLUSIONS

No statistically significant difference was observed between the BioScrew and metal screw groups concerning C5a, TCC, and IL-8 formation. However, some patients in the BioScrew group showed elevated values.

LEVEL OF EVIDENCE

Level II, prospective randomized trial.

[Tularaemia as a differential diagnosis in tumour colli]

BACKGROUND

Tularaemia is a bacterial zoonosis caused by the bacterium Francisella tularensis. Different species of rodents and small mammals are the main reservoir; the transmission of disease is caused by direct contact with diseased animals, via insect vectors, or by ingestion of contaminated food and water. The disease is known to cause a complex clinical presentation in which head and neck manifestations are common. It occurs at a low annual rate in the northern and middle regions of Norway, but in recent years there have been several reported cases also in the southern parts of the country. The incidence of tularaemia is much higher in Sweden compared to Norway; the reason remains obscure.

MATERIAL AND METHODS

In this paper we report two admitted cases in which fever and a solitary neck mass were the predominant clinical findings. We review the number of cases reported to the Norwegian Institute of Public Health from 1976 to 2002, with particular emphasis on the role of tularaemia in the context of a neck tumour and oropharyngeal symptoms.

RESULTS AND INTERPRETATION

The suspicion of tularaemia should be raised in patients with a solitary neck mass of presumed infectious aetiology, in particular when administration of beta-lactam antibiotics has failed. The diagnosis is usually dependent on serological evidence of F. tularensis infection. Recently, PCR techniques have been developed that facilitate rapid detection of F. tularensis in clinical specimens.

Streptococcus agalactiae (group B streptococcus (GBS)) colonisation and persistence, in pregnancy; a comparison of two diverse communities (rural and urban)

OBJECTIVE

To establish the extent of GBS colonisation, persistence of colonisation in pregnancy and influence of obstetric history in two diverse communities (rural and urban) in Zimbabwe.

DESIGN

Cross sectional survey.

SETTING

Rutsanana Clinic in Highfield, Harare (representing the urban area) and Chitsungo Mission Hospital in Lower Guruve, (representing the rural area).

SUBJECTS

300 and 100 pregnant women from the urban and rural areas respectively.

MAIN OUTCOME MEASURES

GBS colonisation and persistence rates for both urban and rural areas were established, together with pregnancy outcome.

RESULTS

Mother colonisation rate was significantly higher in the rural areas (60%) as compared to the urban areas (46%). GBS colonisation persistence was evidently more in rural (48%) that in urban women (12%). Baby colonisation was also more in the rural (23%) that in urban area (5%). In both the rural and urban areas, flu-like illness was a common feature and was equally reported by the subjects. Vaginal discharge requiring treatment, previous stillbirths and previous miscarriages were equally reported in both communities.

Internationally adopted children as a source for MRSA

We describe the import of methicillin-resistant Staphylococcus aureus (MRSA) to Norway by three internationally adopted children from Hunan province in south central China

Gastric juice: a barrier against infectious diseases

All vertebrates produce gastric acid. Its main function is inactivation of ingested microorganisms. The majority of microbiological pathogens ingested never reaches the intestine because of the gastric barrier. Although gastric hypochlorhydria is fairly common due to atrophic gastritis, gastric surgery or use of inhibitors of gastric acid secretion, the resulting susceptibility to infection has not been studied extensively. Drug-induced blockade of acid secretion leads to gastrointestinal bacterial overgrowth; the clinical significance of this is still controversial. Gastric acidity is known to protect against non-typhoid salmonellosis and cholera and it is suspected that it protects against several parasitic diseases as giardiasis and strongyloides. There is a lack of studies focusing on the impact of the gastric acidic barrier on viral infections. Concerning prion infections only a single study has been performed, demonstrating a possible role of gastric acidity in the protection against foodborne prion disease in mice. The combination of malnutrition and hypochlorhydria may contribute to the high prevalence of gastrointestinal infections in developing countries. Further studies are needed to evaluate the clinical consequences of impaired gastric acidity with respect to susceptibility to infections.

Cortical allograft as a vehicle for antibiotic delivery

BACKGROUND

Infection can be a devastating complication after implantation of a cortical bone allograft. The allograft could act as a vehicle for local antibiotic prophylaxis.

MATERIAL AND METHODS

We studied the release of antibiotics in vitro from cortical bone allografts impregnated with antibiotics for different periods of time. We also studied whether cortical allografts impregnated with antibiotics could eradicate Staphylococcus aureus from an experimentally infected graft in vivo. In the in vitro study, pieces of cortical bone were impregnated with netilmicin, vancomycin, ciprofloxacin and rifampicin for 1 h, 10 h and 100 h. The antibiotics were eluted into phosphate-buffered saline (PBS) for 7 days, with daily transfer of the bone into fresh PBS. In the in vivo study, cortical allografts impregnated with antibiotics were placed in rats intramuscularly. 10 microL of an S. aureus suspension (0.6 x 10(5) CFU) was placed in the intramedullary cavity. After 15 days, the allografts were removed and examined for bacterial growth.

RESULTS

The amount of antibiotics released in vitro was influenced by the time used for antibiotic impregnation of the bone. Allografts impregnated with netilmicin, vancomycin and rifampicin effectively eradicated perioperative contamination with S. aureus in vivo.

INTERPRETATION

This study shows that a cortical bone allograft would be an effective vehicle for local antibiotic delivery.

Outbreak of methicillin-resistant Staphylococcus aureus in two nursing homes in Central Norway

Until recently, infections with methicillin-resistant Staphylococcus aureus (MRSA) have mainly been associated with hospital outbreaks in Norway. However, increasingly cases are contracted outside hospitals. This paper reports the first two outbreaks of MRSA in two nursing homes in central Norway, affecting 23 residents and five staff members. Pulsed-field gel electrophoresis analysis showed that all strains from nursing home A were identical and that the strains from nursing home B were genotypically similar with one or two band differences. Multi-locus sequence typing (MLST) showed that the strains from the two nursing homes belong to clonal complex 45, with each strain being a single-locus variant of sequence type 45 (ST 45), a well-known European epidemic strain. No evident source of the two outbreaks was found, and there was no obvious connection between the two outbreaks. The latter is also supported by the minor differences observed by MLST, suggesting a connection at some time in the past. The outbreaks led to a heavier workload and economic strain on both nursing homes. The outbreak in nursing home A was brought to an end, whereas two residents remained colonized in nursing home B despite several eradication attempts. These outbreaks show the potential for MRSA spread in a nursing home. If the prevalence of MRSA in Norway continues to increase, nursing home staff and residents may have to be included in the groups to be screened for MRSA upon hospital admission.

Ruptured abdominal aortic aneurysm secondary to tuberculous spondylitis

A 69-year-old man was admitted with low back pain and signs of nerve root compression. A computed tomography (CT) scan showed abscess formation in the left psoas region, spondylodiscitis L3-L4 and a ruptured abdominal aortic aneurysm. The aortic aneurysm was replaced with a bifurcated vascular graft. One week later, laminectomy at the L4-level was done. In a small abscess, Mycobacterium bovis was found. The condition was considered to be a mycobacterial spondylitis secondary to BCG instillations of the urinary bladder for carcinoma. The patient received antituberculous medication for 9 months. Subsequently bone transplantation and internal fixation of the spine became necessary. Three years after surgery he is in good condition and there are no signs of graft infection on CT. Spondylitis and mycotic aortic aneurysm should be kept in mind in patients who have been treated for carcinoma of the bladder with BCG instillations.

Association of atypical enteropathogenic Escherichia coli (EPEC) with prolonged diarrhoea

The aim of the present case control study was to investigate the prevalence of atypical enteropathogenic Escherichia coli (EPEC) and its possible role in causing diarrhoea among children < 5 years of age in Norway. Stool specimens received in the laboratory from children with suspected gastroenteritis (n = 251) were, in addition to routine testing, analysed for the presence of EPEC by PCR of the eae, bfpA and stx genes. Specimens from healthy children (n = 210) recruited from Maternal and Child Health Centres were analysed for EPEC only. EPEC isolates (eae+, stx-) were classified as typical (bfpA+) or atypical (bfpA-), and were tested for O : K serogroup. Information on duration of diarrhoea was recorded in a questionnaire and from referral forms. Atypical EPEC was diagnosed in 37 patients (14.7 %) compared to 21 (10.0 %) of the healthy controls [Odds ratio (OR) = 1.4, P = 0.3]. Only three isolates, all from patients, belonged to EPEC serogroups. One patient had typical EPEC. Twenty (22.5 %) of 89 patients with diarrhoea lasting > or = 14 days had atypical EPEC. The association between atypical EPEC and prolonged diarrhoea (OR = 2.1, P = 0.04) was caused by a high prevalence among female patients (40.6 %). In conclusion, atypical EPEC was found to be slightly more prevalent in patients than controls, without any overall significant association with diarrhoea. However, a significant association was observed with diarrhoea lasting 14 days or more, a finding that may indicate a role for atypical EPEC in prolonged disease.

Distribution of PFGE types of invasive Norwegian group B streptococci in relation to serotypes

BACKGROUND & OBJECTIVES

Pulsed-field gel electrophoresis (PFGE) has been used for characterisation of group B streptococci, non-typeable by serotyping. We wanted to compare PFGE with serotyping in order to see the how well the method discriminates between epidemiological unrelated strains.

METHODS

A total of 78 epidemiological unrelated invasive GBS strains were examined by PFGE using SmaI digested chromosomal DNA. Of these, 11 were nontypeable (NT) with regard to capsular polysaccharide (CPS) serotype. PFGE patterns were analyzed and classified in a dendrogram.

RESULTS

75 strains were typeable by PFGE, and a total of 62 restriction profiles were identified. At an 85 per cent similarity level, 53 different PFGE patterns were identified. Within each serotype, PFGE patterns differed considerably, the largest degree of heterogeneity observed among type IV, Ia, and II strains. Serotype Ib, III, and V strains were more homogeneous. Strains with identical macrorestriction profiles belonged to the same CPS type, but varied with regard to serosubtypes. Any strain among the ones investigated showing a greater than 88 per cent similarity to a restriction profile in the database, could correctly be ascribed to a particular CPS type. Of the 11 NT strains 10 restriction profiles were found, two of which were identical to the PFGE profile for a cluster of type V strains, and one profile were identical to the profile showed by a cluster of 5 type Ib strains.

INTERPRETATION & CONCLUSION

PFGE is a useful technique for classifying strains that are non-typeable by conventional serotyping.

Detection of group B streptococci (GBS) in vaginal swabs using real-time PCR with TaqMan probe hybridization

BACKGROUND & OBJECTIVES

Implementation of a screening based strategy for the prevention of perinatal group B streptococcus (GBS) disease is anticipated to increase the demand of fast laboratory techniques. The aim of the present study was to develop a real-time PCR method for the specific detection of GBS in vaginal swabs.

METHODS

Based on partial sequencing of the sip gene, primers and a TaqMan hybridization probe were constructed for a real-time PCR assay. The performance of the assay was tested on 100 consecutive vaginal specimens submitted to the laboratory for culture. Lysis of bacteria and DNA extraction was performed by lysozyme, mutanolysin, proteinase K and Quiagen spin columns. PCR was performed using LightCycler. Highly purified DNA from GBS was used as positive control.

RESULTS

Of the 100 samples investigated, 25 were positive by culture (16 abundant/moderate growth, 6 sparse growth and 3 after enrichment only). At a cut-off of 12 fg per reaction (corresponding to 4 bacterial cells), PCR was positive in 32 samples. A complete concordance was noted between PCR positivity and abundant/moderate and sparse growth by culture. One of 3 samples that were positive by culture only after enrichment was negative in PCR. On the other hand, 8 samples were positive by PCR and negative by culture.

INTERPRETATION & CONCLUSION

The real-time PCR assay was sensitive and rapid and enabled detection of GBS in less than 2 h after collection. Due to the rapidity of the assay by which results could be obtained, the assay harbors the potential for intrapartum detection of GBS.

High prevalence of atypical enteropathogenic Escherichia coli (EPEC) in Norwegian children with diarrhoea

The aim of the present study was to investigate the relative contribution of enteropathogenic Escherichia coli (EPEC) as a cause of infectious diarrhoea in Norwegian children. Data from faecal specimens from children <2 years old with diarrhoea during the year 2001 were analysed. E. coli isolates with the attaching and effacing genotype (eae+) were examined for the presence of the bundle-forming pilus (bfpA) and Shiga toxin genes by PCR, and for genetic relatedness by PFGE. During the 1-year period, 598 specimens from 440 patients <2 years old were analysed. Potential enteric pathogens were identified in 124 patients (28.2 %). EPEC was the most frequently identified agent (44 patients), followed by rotavirus (41 patients), Campylobacter jejuni (17 patients) and adenovirus (17 patients). All other agents were detected in five patients or less. Only one of the eae+ E. coli isolates was classified as typical EPEC (bfpA+). Among the 43 isolates that were classified as atypical EPEC (bfpA-), eight strains belonged to EPEC serogroups, whereas the majority of strains (n = 35) were not agglutinated by EPEC antisera. None of the EPEC isolates were genetically related. This study demonstrates that atypical EPEC of non-EPEC serogroups is highly prevalent among Norwegian children with diarrhoea.

Anti-C5a monoclonal antibodies and pulmonary polymorphonuclear leukocyte infiltration--endothelial dysfunction by venous gas embolism

Venous gas embolism (VGE) impairs endothelial function although there is no apparent mechanical damage to the endothelial layer. We investigated whether a monoclonal antibody against the complement anaphylatoxine C5a would affect endothelial dysfunction and pulmonary polymorphonuclear leukocyte infiltration caused by low-grade VGE. Six rabbits were pre-treated with the anti-C5a monoclonal antibody whereas a sham monoclonal antibody was administrated to six other animals 30 min before VGE. Six untreated rabbits subjected to an identical protocol except antibody treatment were used for control. The monoclonal anti-C5a antibody reduced PMN infiltration compared to the control group ( P<0.03). There were no major signs of apoptosis in endothelial cells inside the pulmonary artery in any of the examined animals. There was reduced PMN infiltration and improved endothelium-dependent relaxation in the sham-antibody group, these effects were however not significant. In conclusion, anti-C5a protects the endothelium against injury caused by small amounts of gas bubbles.

Typing of human isolates of Streptococcus agalactiae (group B streptococcus, GBS) strains from Zimbabwe

Serotyping and genotyping are important tools in epidemiological studies of group B streptococcal (GBS) infections, which are important diseases in man, particularly in newborns. In the present study, 241 GBS isolates from Zimbabwe, comprising 124 carrier isolates from pregnant women and 117 isolates from patients hospitalised for various diseases, were serotyped. Antibodies specific for the capsular polysaccharide antigens (CPAs) Ia, Ib and II-V and antibodies specific for the surface-localised proteins, c(alpha), c(beta), R1, R3 and R4 were used for serotyping. Strains of the CPA types Ia (17%), III (47.7%) and V (23.2%) predominated. Of the various protein antigens, c(alpha) and R4 were expressed with highest frequency, c(alpha) by 100% of the CPA type Ia strains and R4 by 92% of the CPA type III strains. The R3 protein occurred frequently (24%), especially in type V strains (84%). A total of 25 serovariants was detected in the strain collection with the variants Ia/c(alpha) (16%), III/R4 (43.5%) and V/c(alpha), R3 (14.1%) occurring with the highest frequency. Serotype and subtype distribution of the carrier isolates were essentially similar to those of the disease-associated isolates. Genomic heterogeneity was demonstrated by pulsed-field gel electrophoresis of type III/R4 and type V/c(alpha), R3 isolates, but to a much lesser extent than recorded with Norwegian strains. These results demonstrate that many variants of GBS occur in the Zimbabwean population. The data obtained may assist in the formulation of a possible future GBS vaccine for Zimbabwe and perhaps for other African countries.

Posttrabeculectomy endophthalmitis caused by Moraxella nonliquefaciens

Moraxella nonliquefaciens, a commensal organism of the upper respiratory tract, is generally considered to have low pathogenic potential. We report here two cases of severe endophthalmitis occurring 9 years and 2 months after glaucoma filtration surgery, respectively. Apart from sulfonamide, very low MICs were recorded for several antibiotics tested. Identification was based on phenotypic characteristics in combination with sequencing of the 16S rRNA gene.

Low prevalence of Bartonella henselae infections in Norwegian domestic and feral cats

Bartonella henselae is the causative agent of cat scratch disease (CSD). This clinical entity is very rarely encountered in human medical practice in Norway. B. henselae infections including bacteraemia in cats have been frequently reported. The objective of the present study was to investigate the seroprevalence rate and the degree of B. henselae bacteraemia in Norwegian domestic and feral cats. One hundred cats investigated at a small animal veterinary practice in the middle of Norway were included in the study. Blood collected in Isolator blood-lysis tubes and lysates of erythrocytes after freezing and thawing were cultured. PCR analysis of whole blood was also performed. Serology was performed by indirect fluorescence assay (IFA) and enzyme immunoassay (EIA) using immobilised B. henselae Houston-1 strain as antigen. None of the 100 cats investigated was found to be bacteraemic. All 100 cats were seronegative when analysed by IFA; one cat was positive by EIA. The discrepancy between IFA and EIA of this particular cat is probably due to cross-reactive antibodies. Contrary to findings reported from several geographic regions, B. henselae infections in Norwegian cats appear to be virtually absent. This in turn may explain why CSD has not been reported in human medical practice in Norway.