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.

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.

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.

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.

Francisella tularensis bacteremia.

Bacteremia caused by Francisella tularensis is rare and has been reported mainly in the United States and infrequently in Europe. We report herein the first case of bacteremic F. tularensis pneumonia in an immunocompetent individual in southern Europe.

Anogenital bacteriology in non-abused preschool children: a descriptive study of the aerobic genital flora and the isolation of anogenital Gardnerella vaginalis.

The purpose of the study is to describe the genital aerobic bacterial flora including Gardnerella vaginalis in girls and the occurrence of anal G. vaginalis in both genders. From a group of 3773 children, 278 (99 boys and 179 girls) with a mean age of 5.63 y (range: 5.13-6.73) were recruited. Inclusion in the study was based on self-selection, whereby parents who did not suspect any occurrence of sexual abuse of their child gave informed consent to participate. Several mechanisms were undertaken to exclude abused children. At least one bacterial species was isolated from the genitals of 59 (33.9%) girls. Most isolates (39 out of 99) were bacteria representing skin flora (staphylococci and coryneform organisms), with viridans streptococci and related organisms as the second most common group of isolates (31 out of 99). S. anginosus was the single most frequent bacterial species identified (17 isolates). Streptococcus pyogenes was isolated from the genitals of two girls, Streptococcus pneumoniae from one girl and Haemophilus influenzae from eight girls. G. vaginalis was not isolated from the genitals in any girl, but the organism was isolated from the anal canal in three children.

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.

Peritoneal dialysis-associated peritonitis caused by Dermabacter hominis.

Dermabacter hominis was the cause of a peritoneal dialysis-associated peritonitis. D. hominis was identified by phenotypic criteria and by sequencing the 16S rRNA gene. Clinical cure was achieved with cefuroxime treatment despite the isolate's reduced susceptibility to this drug (MIC, 12 mg/liter) on in vitro testing. The successful treatment was probably due to the high concentrations attained by intraperitoneal administration of the drug.

Antibiotic sensitivity still prevails in Norwegian blood culture isolates.

We describe the antimicrobial susceptibility of bacteraemia isolates from Norway. From March 1998 to February 1999, four university hospitals covering all parts of Norway collected their first 10 isolates each month. Minimal inhibitory concentrations were determined for: Enterobacteriaceae (n=192), staphylococci (n=89) and Streptococcus pneumoniae (n=69) using the Etest. NCCLS breakpoints were used. About 20% of all blood culture isolates in Norway in this period were investigated. Compared with countries outside Scandinavia antibiotic sensitivity still prevails. Only minor differences in resistance were found between participating hospitals, between hospital departments and between hospital- and community-acquired pathogens. The prudent use of antibiotics in Norway may contribute to the fact that antibiotic resistance still remains low in the most common bacterial pathogens causing bloodstream infections.

Distribution and expression of bca, the gene encoding the c alpha protein, by Streptococcus agalactiae.

A total of 52 clinical isolates of group B streptococci (GBS) was tested for expression of the c protein c(alpha) by a fluorescent antibody test (FAT) and by PCR amplification of a 202-bp stretch within the repeat unit of the bca gene encoding the c(alpha) protein. The strains were categorised as follows: c(alpha) FAT positive and PCR positive with amplification products of multiple sizes (category A, n = 12); FAT negative and with PCR products of multiple sizes (category B, n = 11); FAT negative and with a single PCR product of c. 200 bp (category C, n = 5); negative in both tests (category D, n = 24). A single amplification product of minimum size and additional products of larger sizes corresponded to one and more bca repeats, respectively. Five of the 11 category B strains showed expression of low Mr c(alpha) in whole cell-based Western blotting. The results showed that a proportion of the GBS isolates harboured bca gene elements that either were not expressed or they expressed c(alpha) molecular variants which could not be detected by the whole cell-based FAT. This genotype/phenotype discrepancy should be considered in relation to GBS typing, including the selection of antibody reagents and the technical approach to c(alpha) protein detection.

bca, beta gene, and gene product divergency in reference and prototype strains of streptococcus agalactiae.

Reference and prototype strains of Streptococcus agalactiae (GBS) were originally selected on the basis of phenotypic traits which, however, do not always mirror genotypic traits. A total of 14 reference and prototype GBS strains were examined by PCR designed to detect the bca and beta genes, encoding the c proteins c(alpha) and c(beta), respectively. The cognate proteins were detected by whole-cell-based fluorescent antibody testing and Western blotting. The PCR for beta gene detection and the antibody-based c(beta) protein detection showed concordant results with all of the isolates, whereas 7 of 14 strains which did not express c(alpha) protein at detectable levels contained bca gene elements, consistent with bca gene and gene product divergency in these strains. The results emphasize the importance of genetic characterization of reference and prototype strains of GBS which, in the past, have been selected on the basis of phenotypic traits.

Properties and distribution of the putative R3 protein of Streptococcus agalactiae.

Strain-variable Streptococcus agalactiae (group B streptococci; GBS) proteins exposed at the bacterial cell surface are important markers in GBS serotyping. These proteins include the c proteins c(alpha) and c(beta) and the R proteins R1 through R4, of which R1 and R4 have been studied most extensively. This study presents the characteristics of a protein which was expressed by a capsular antigen type V GBS strain shown by means of polyclonal and monoclonal antibody testing. Examination of a number of reference and prototype strains by fluorescent antibody testing and Western blotting provided evidence that the serotype V-derived protein was the R3 protein of GBS, previously defined on the basis of immunoprecipitation assays. The putative R3 protein formed ladder-like banding patterns on Western blotting with polypeptides in the 30 kDa to > or = 140 kDa range, was destroyed by pepsin digestion, and partially degraded by trypsin digestion. The protein was expressed by 10 (6.5%) of 153 clinical GBS strains tested, the expression being restricted to isolates of the capsular antigen types II, III, and V. Some isolates expressed both the c(beta) and the R3 protein. Expression in combination with c(alpha) or R4 protein synthesis was not detected. Inclusion of the anti-R3 monoclonal antibody among antibody reagents for GBS serotyping will enhance the discriminatory power of this typing method.

[Pregnant women themselves can take specimens for identification of group B streptococci carriers]. / Gravide kan selv ta prøver for påvisning av baerertilstand for gruppe B-streptokokker.

Prenatal screening for group B streptococcus colonisation in pregnant women is controversial, though recommended in some countries. We aimed to compare the detection rate when pregnant women performed their own vaginal/anorectal swabs with the standard practice of physician obtained swabs. During six months, 89 pregnant women with high risk for premature labor collected their own vaginal/anorectal swab after instruction from a midwife. Afterwards a physician took a similar sample among 80 of the women. All together, 30 (34%) out of 89 women were carriers of group B streptococcus. Comparing the efficacy of the sampling procedures among 80 women who had taken both tests, we found that 25 of 26 positive cultures were identified by self-collected samples, while 17 out of 26 were identified by samples collected by the physicians. The difference in sensitivity (96% vs 65%) was statistically significant (p < 0.001) with a kappa value of 0.68. Self-collected vaginal/anorectal swabs for the identification of group B streptococcus carriers are at least as sensitive as the practice of physician performed swabs.

Comparison of three different methods in monoclonal antibody-based detection of Streptococcus agalactiae protein serotype markers.

Surface-exposed proteins are important serotype markers in Streptococcus agalactiae (group B streptococci; GBS). The proteins include the c proteins c(alpha) and c(beta), the R4 protein and a protein provisionally called P. For all of these markers, protein-specific monoclonal antibodies (MAbs) have been generated. We have compared whole-cell-based fluorescent antibody testing (FAT), ELISA, and dot blotting for MAb-based detection of these proteins by testing a panel of 52 GBS isolates of different capsular antigen types. Of a total of 208 observations with each of the tests, positive signalling in the dot assay was observed in 32.2%, with ELISA in 27.8%, and with FAT in 26.4% of the recordings. Discordant results were noted most frequently with the c(beta) and c(alpha) MAbs. In the case of c(alpha) the reason for the discordant test results was further examined and it appeared that this could be attributed to low level expression of the c(alpha) protein, although structural variations of c(alpha) proteins cannot be excluded. Our findings favour dot blotting as the method of choice although we consider all three methods acceptable for serotyping of GBS.

Constant low rate of fungemia in norway, 1991 to 1996. The Norwegian Yeast Study Group.

Since 1991 information on yeast isolates from blood cultures has been recorded prospectively from all microbiological laboratories (5 university and 16 county or local hospital laboratories) in Norway (population, 4.3 million). From 1991 to 1996 a total of 571 episodes of fungemia in 552 patients occurred (1991, 109 episodes; 1992, 81 episodes; 1993, 93 episodes; 1994, 89 episodes; 1995, 98 episodes; and 1996, 101 episodes). The fungemia rates per 10,000 patient days were 0.29 in 1991 and 0.27 in 1996. The average rates for the years 1991 to 1996 were 0.37 for the university laboratories and 0.20 for the other laboratories. These rates are low compared to the rate (0. 76) in five Dutch university hospitals in 1995 and the rate (2.0) in Iowa in 1991. The four most frequently isolated species were Candida albicans (66%), Candida glabrata (12.5%), Candida parapsilosis (7.6%), and Candida tropicalis (6.4%). The incidences of both C. albicans (range, 63 to 73%) and C. glabrata (range, 8.4 to 15.7%) varied somewhat throughout this period, but no significant increase or decrease was noted. MICs of amphotericin B, flucytosine, and fluconazole were determined for 89% of the isolates. All were susceptible to amphotericin B, and only 29 (5.6%) strains had decreased susceptibility to flucytosine. All C. albicans isolates were susceptible to fluconazole. The percentage of yeast isolates with decreased susceptibility to fluconazole (MICs, >/=16 microgram/ml) did increase, from 9.6% in 1991 and 1992 to 12.2% in 1994, 16.1% in 1995, and 18.6% in 1996. This was largely due to increases in the percentages of resistant C. glabrata and Candida krusei strains in the last 2 years. Compared to the incidence in other countries, it is remarkable that Norway has such a low and constant incidence of fungemia. A possible reason for this difference might be a restricted antibiotic use policy in Norway.

Identification of nasopharyngeal carriage of an outbreak strain of Neisseria meningitidis by pulsed-field gel electrophoresis versus phenotypic methods.

The clustering of four cases of meningococcal disease during a 3-month period in a small community with 2233 inhabitants prompted an interventional carrier survey in persons < 19 years old and in family members of the patients. The aims of the survey were to identify the nasopharyngeal carriers and the carriage rate of the outbreak strain, to offer chemoprophylaxis to those carrying the outbreak strain, and to study the discriminatory power of phenotypic methods versus pulsed-field gel electrophoresis (PFGE) on carrier isolates during an outbreak. A high percentage of the population in the age group 0-19 years (73.7%) participated in the study. Among the 469 samples collected in this age group, meningococci were grown from 43 (9.2%). The highest carriage rates were in the age group 18-19 years (36.4%). With a provisional definition of the outbreak strain (group B or non-groupable Neisseria meningitidis with reduced sulphonamide sensitivity), six carriers were identified. All were treated with a single dose of ofloxacin. Four of these persons (0.76% of all tested) were later shown to have harboured the outbreak strain when analysed by PFGE. Three of them were epidemiologically closely related to one of the index cases. Serogrouping alone is not sufficient for the identification of an epidemic strain of N. meningitidis. Complete concordance of type and subtype antigens correctly identified the outbreak strain in this study. PFGE is well suited for the identification of an outbreak strain of N. meningitidis versus non-epidemic strains in tonsillo-pharyngeal specimens.

[Spotted fever after travel to South Africa]. / Flekkfeber etter opphold i Søor-Afrika.

Three patients developed fever, malaise and a typical maculopapular rash a few days after returning to Norway from South Africa. In South Africa they had been bitten by ticks several times while hunting. Two patients, with lesions compatible with eschar, were hospitalized, and a diagnosis of rickettsial spotted fever was established based on the clinical presentation and positive Rickettsia conorii serology. Rickettsial diseases are extremely rare in Scandinavia, and a survey on rickettsioses is presented in this paper.

Cervical secretions in pregnant women colonized rectally with group B streptococci have high levels of antibodies to serotype III polysaccharide capsular antigen and protein R.

Group B streptococci (GBS) colonizing the female genital tract will often infect newborn infants during delivery. In 200 pregnant women studied, 14% were colonized with GBS in the cervix, 12% in the rectum, and 9% in both cervix and rectum. We have previously reported that antibody levels to GBS serotypes Ia, II, and III in sera and cervical secretions were increased in women colonized in the rectum and/or cervix, when analyzed by a whole-cell ELISA. Here, we report the levels of antibodies to GBS serotype III capsular polysaccharide antigen (CPS III) and to protein antigen R4, which are present in most GBS III strains. Compared to culture-negative women, the group of women colonized rectally had markedly elevated levels of immunoglobulin (Ig)A and IgG antibodies in cervical secretions to both CPS III and protein R4 (P < 0.01 and P < 0.001, respectively). In sera, the corresponding differences between culture-negative and culture-positive women were less pronounced, or not present. In contrast to antibody levels to whole-cell GBS, antibody levels to CPS III and protein R4 in cervical secretions were not significantly increased in women colonized only in the cervix, except that IgA antibodies to protein R4 were slightly elevated (P < 0.05). These findings suggest that capsular type-specific polysaccharides and protein R4 in a mucosal vaccine might induce protective antibodies against GBS colonization of the uterine cervix.

Streptococcus agalactiae beta gene and gene product variations.

Streptococcus agalactiae (group B streptococci; GBS) are serotyped on the basis of the capsular polysaccharide antigens and subtyped on the basis of the strain-variable and surface-localised c proteins c alpha, c beta, and R proteins. This study compared c beta protein detection and the polymerase chain reaction (PCR) for beta gene detection, by examining 50 clinical GBS strains. The c beta protein was detected by antibody-based immunofluorescence in a GBS whole-cell assay and Western blotting by probing with the anti-c beta antibody or human IgA. Absorption experiments were performed to test for surface-anchoring of c beta; and bacterial supernates were examined to test for c beta production. Primers for the PCR target regions resulted in a 620-bp product that included beta gene-encoding IgA-binding domains. The results demonstrated four categories of GBS with respect to the beta gene and the c beta protein: (1) strains (16 of 50) that harboured the beta gene and regularly expressed normal surface-localised c beta with a M(r) of 120 kDa; (2) strains (5 of 50) that harboured the gene but did not express the protein; (3) strains (2 of 50) that harboured the gene but expressed a c beta that was not surface-localised and had reduced M(r); (4) strains (27 of 50) without beta gene and c beta expression. One strain amongst the third group generated a PCR product of 1330 bp. These results demonstrate considerable strain variability of the beta gene of GBS and of its product the c beta protein.