- Volume 55, Issue 8, 2006
Volume 55, Issue 8, 2006
- Obituary
-
- Reviews
-
-
-
Control of pneumococcal disease in the United Kingdom – the start of a new era
More LessIn 2000, a multi-valent pneumococcal conjugate vaccine, known as Prevnar, was licensed for use in infants and young children in the USA. The subsequent introduction of the vaccine into the childhood immunization schedule in that country led to a significant decrease in pneumococcal disease. The vaccine is effective against invasive and non-invasive pneumococcal infection, can be used in young children as well as adults and, like all conjugate vaccines, provides long-lasting immunity. Moreover, it reduces the incidence of antibiotic resistance because a number of resistant serotypes are targeted by the vaccine. Prevnar, also known as Prevenar, has since been licensed in numerous countries, including the UK. On 8 February 2006, the Departments of Health in England, Scotland and Wales announced the inclusion of Prevenar in the childhood immunization schedule. This announcement has important implications for pneumococcal infection, disease surveillance and immunization policy in the UK.
-
-
-
-
Endocarditis caused by Propionibacterium species: a report of three cases and a review of clinical features and diagnostic difficulties
More LessPropionibacterium species are members of the normal flora of skin and the mouth but their pathogenic potential is often overlooked. Three fatal cases of endocarditis caused by Propionibacterium species over an 8-year period are reported, and a review is presented of a further 33 cases from the world literature. In most cases, infection was protracted, with minimal signs in the early stages. Fourteen cases (42.4 %) involved native valves, 16 (48.5 %) involved prosthetic valves and three (9.1 %) were associated with other intracardiac prosthetic material. Intracardiac abscesses were commonly encountered, with Propionibacterium endocarditis occurring in 28.6 % of native valve infections and 52.9 % of prosthetic valve infections. A very high proportion of all of the cases (70.6 %) required surgical intervention. Several factors appeared to delay institution of appropriate therapy and may have contributed to abscess formation, including an indolent clinical course, negative or delayed culture results, and the tendency to consider this organism as a blood-culture contaminant. The authors recommend careful clinical evaluation before disregarding a blood-culture isolate of Propionibacterium spp. as a skin contaminant, and consideration of this bacterium as a potential cause of apparently culture-negative endocarditis.
-
- Pathogenicity And Virulence
-
-
-
Increased recovery of Moraxella catarrhalis and Haemophilus influenzae in association with group A β-haemolytic streptococci in healthy children and those with pharyngo-tonsillitis
More LessThe inflamed tonsils harbour numerous types of bacteria, alone or in combination with group A β-haemolytic streptococci (GABHS). The cohabitation of the tonsils by GABHS and certain other bacterial species may contribute to the inflammatory process and the failure of penicillin therapy. This study evaluated the recovery of Moraxella catarrhalis, Haemophilus influenzae, Staphylococcus aureus and Streptococcus pneumoniae in association with GABHS in healthy children and those with acute pharyngo-tonsillitis (APT). Pharyngo-tonsillar cultures were obtained from 548 children with APT and 866 healthy children. GABHS was recovered from 112 (20.4 %) children with APT. Of the 114 H. influenzae isolates, 32 were recovered in association with GABHS (29 % of all patients who had GABHS) and 82 were isolated without GABHS (19 %) (P=0.0267). Of the 69 M. catarrhalis isolates, 25 were recovered in association with GABHS (22 % of all patients who had GABHS) and 44 were isolated without GABHS (10 %) (P=0.0012). In contrast, there was no association between the isolation of GABHS and the recovery of Staph. aureus or Strep. pneumoniae. GABHS was recovered from 104 (12 %) healthy children. Of the 69 M. catarrhalis isolates, 24 were recovered in association with GABHS (23 % of all patients who had GABHS) and 80 were isolated without GABHS (10 %) (P=0.006). There was no association between the isolation of GABHS and the recovery of H. influenzae, Staph. aureus or Strep. pneumoniae. This study demonstrates an association between the recovery of GABHS and H. influenzae and M. catarrhalis from pharyngo-tonsillar cultures of patients with APT and M. catarrhalis from pharyngo-tonsillar cultures of healthy children.
-
-
-
-
Distribution of 19 major virulence genes in Legionella pneumophila serogroup 1 isolates from patients and water in Queensland, Australia
The distribution of 19 major virulence genes and the presence of plasmids were surveyed in 141 Legionella pneumophila serogroup (SG) 1 isolates from patients and water in Queensland, Australia. The results showed that 16 of the virulence genes examined were present in all isolates, suggesting that they are life-essential genes for isolates in the environment and host cells. The 65 kb pathogenicity island identified originally in strain Philadelphia-1T was detected more frequently in isolates from water (44.2 %) than in those from patients (2.7 %), indicating that the 65 kb DNA fragment may aid the survival of L. pneumophila in the sampled environment. However, the low frequency of the 65 kb fragment in isolates from patients suggests that the pathogenicity island may not be necessary for L. pneumophila to cause disease. Plasmids were not detected in the L. pneumophila SG1 isolates from patients or water studied. There was an association of both lvh and rtxA with the virulent and predominant genotype detected by amplified fragment length polymorphism, termed AF1, whereas the avirulent common isolate from water termed AF16 did not have lvh or rtxA genes, with the exception of one isolate with rtxA. It was found that a PCR detection test strategy with lvh and rtxA as pathogenesis markers would be useful for determining the infection potential of an isolate.
-
-
-
Biofilm matrix of Candida albicans and Candida tropicalis: chemical composition and role in drug resistance
More LessMatrix material was extracted from biofilms of Candida albicans and Candida tropicalis and analysed chemically. Both preparations contained carbohydrate, protein, hexosamine, phosphorus and uronic acid. However, the major component in C. albicans matrix was glucose (32 %), whereas in C. tropicalis matrix it was hexosamine (27 %). Biofilms of C. albicans were more easily detached from plastic surfaces by treatment with the enzyme lyticase (β-1,3-glucanase) than were those of C. tropicalis. Biofilms of C. albicans were also partially detached by treatment with proteinase K, chitinase, DNase I, or β-N-acetylglucosaminidase, whereas C. tropicalis biofilms were only affected by lipase type VII or chitinase. To investigate a possible role for the matrix in biofilm resistance to antifungal agents, biofilms of C. albicans were grown under conditions of continuous flow in a modified Robbins device (MRD). These biofilms produced more matrix material than those grown statically, and were significantly more resistant to amphotericin B. Biofilms of C. tropicalis synthesized large amounts of matrix material even when grown statically, and such biofilms were completely resistant to both amphotericin B and fluconazole. Mixed-species biofilms of C. albicans and a slime-producing strain of Staphylococcus epidermidis (RP62A), when grown statically or in the MRD, were also completely resistant to amphotericin B and fluconazole. Mixed-species biofilms of C. albicans and a slime-negative mutant of S. epidermidis (M7), on the other hand, were completely drug resistant only when grown under flow conditions. These results demonstrate that the matrix can make a significant contribution to drug resistance in Candida biofilms, especially under conditions similar to those found in catheter infections in vivo, and that the composition of the matrix material is an important determinant in resistance.
-
- Host Response
-
-
-
Gene-expression profiles in gastric epithelial cells stimulated with spiral and coccoid Helicobacter pylori
More LessHuman gastric epithelial immortalized GES-1 cells were infected with spiral and coccoid Helicobacter pylori. Scanning electron microscopy was used to determine the ability of the two forms of H. pylori to adhere to GES-1 cells. GES-1 cell apoptosis induced by coccoid and spiral H. pylori was analysed using flow cytometry. A cDNA microarray for 22 000 human genes was used to identify the gene-expression differences in GES-1 cells infected with the two forms of H. pylori, and the gene expression identified by the cDNA microarray was confirmed by RT-PCR. Scanning electron microscope observation showed that both coccoid and spiral bacteria can adhere to GES-1 cells. After 4 h infection, apoptosis induction was 27.4 % for spiral-form infection and 10.2 % for coccoid-form infection. Of 268 differentially expressed genes identified by cDNA microarray, 166 showed higher expression with the spiral H. pylori infection than with the coccoid H. pylori infection. To the best of the authors' knowledge, this is the first report that GES-1 cells infected with spiral H. pylori have higher expression of cxcl10, ccl11, ccl5, groα, TLR5, ATF3, fos, fosl2, gadd45a and myc. The cells infected with coccoid H. pylori had higher expression of survivin. The global profile of gene expression in GES-1 cells infected with coccoid and spiral H. pylori is described for the first time.
-
-
-
-
Increased prostanoid dependency of arterial relaxation in Chlamydia pneumoniae-infected mice
More LessEndothelial dysfunction plays an important role in the development of atherosclerosis. Previous studies have shown that inoculation with Chlamydia pneumoniae contributes to atherosclerotic development in rabbits and hypercholesterolaemic mice and causes endothelial dysfunction in apolipoprotein E-deficient mice. The effect of acute C. pneumoniae infection on endothelial function in normocholesterolaemic C57BL/6J mice was studied by measuring the force of contraction of the descending aorta after noradrenaline stimulation and in response to methacholine-induced relaxation. In addition, the effects of the nitric oxide synthase inhibitor Nω -nitro-l-arginine methyl ester (l-NAME) and the cyclooxygenase inhibitor diclofenac on relaxation were assessed. Pre-treatment of the aortas with l-NAME decreased the relaxation response in both the infected and uninfected groups and no significant difference was detected between these groups, whereas diclofenac significantly attenuated the relaxation response only in the infected animals. In conclusion, infection shifted the balance of endothelium-derived relaxing factors from nitric oxide towards vasorelaxing prostanoids in C57BL/6J mice.
-
-
-
A microarray analysis of the murine macrophage response to infection with Francisella tularensis LVS
More LessThe response of cells of the mouse macrophage cell line J774 to infection with Francisella tularensis LVS was analysed by means of a DNA microarray representing approximately 18 500 genes (20 600 clones). The adaptive response was modest at all time points, and at most, 81 clones were differentially regulated from the time point of uptake of bacteria (0 min) up to 240 min later. For all five time points, 229 clones fulfilled the criteria of being differentially regulated, i.e. the ratio between infected versus non-infected cells was at least 1.7-fold up- or down-regulated and P <0.05. It was found that many of the differentially regulated genes are known to respond to stress in general and to oxidative stress specifically. However, at 120 min it was observed that genes that lead to depletion of glutathione were upregulated. Possibly, this was a result of mechanisms induced by F. tularensis. Generally, there was a conspicuous lack of inflammatory responses and, for example, although tumour necrosis factor alpha (TNF-α) was upregulated at 0 min, a significant down-regulation was noted at all subsequent time points. When cells were treated with an inhibitor of inducible nitric oxide synthase (iNOS) or the antioxidant N-acetylcysteine (NAC), the infection-induced cytopathogenic effect was significantly inhibited. Together, the results suggest that F. tularensis LVS infection confers an oxidative stress upon the target cells and that many of the host-defence mechanisms appear to be intended to counteract this stress. The infection is characterized by a very modest inflammatory response.
-
- Diagnostics, Typing And Identification
-
-
-
Molecular typing of enteroviruses associated with viral meningitis in Cyprus, 2000–2002
More LessHuman enteroviruses are responsible for a wide spectrum of clinical diseases affecting many different organ systems. Although infection is usually asymptomatic, infections of the central nervous system manifested as meningitis or encephalitis can pose a serious public health problem, especially during outbreaks. In this study, samples from 218 patients diagnosed with enteroviral meningitis between January 2000 and December 2002 were analysed in order to assess the epidemiology of human enteroviruses as a cause of viral meningitis in Cyprus. A new typing strategy, based on partial sequencing of the 5′ non-coding region (5′NCR), prediction of type, and selection of type-specific primers for sensitive VP1 PCR amplification, was developed. As clustering in the 5′NCR was concordant with clustering in the VP1 region, quick and reliable typing by VP1 sequencing was achieved without virus isolation in cell culture. The most frequent enterovirus serotypes identified were Human echovirus 30 (55.5 %), Human echovirus 13 (15.1 %), Human echovirus 6 (13.8 %) and Human echovirus 9 (8.3 %). Human coxsackieviruses B2, B1 and B5, Human echovirus 4, Human enterovirus 71 and Human coxsackievirus A6 represented rather rare serotypes. This is the first molecular epidemiological study of enterovirus meningitis in Cyprus. Serotype distribution corresponded basically with observations in other European countries, suggesting the spread of enteroviruses by tourism.
-
-
-
-
Bordetella holmesii DNA is not detected in nasopharyngeal swabs from Finnish and Dutch patients with suspected pertussis
Bordetella holmesii is a Gram-negative bacterium first identified in 1995. It can cause pertussis-like symptoms in humans. B. holmesii contains insertion sequences IS481 and IS1001, two frequently used targets in the PCR diagnosis of Bordetella pertussis and Bordetella parapertussis infections. To investigate the prevalence of B. holmesii in Finnish and Dutch patients with pertussis-like symptoms and whether B. holmesii has caused any false-positive results in diagnostic PCRs, B. holmesii-specific real-time PCRs were developed. The Finnish methods were conventional IS481 PCR and B. holmesii-specific real-time PCR (LightCycler, Roche) targeting the B. holmesii recA gene. The Dutch methods were IS481 and IS1001 PCRs with conventional or real-time formats and B. holmesii-specific real-time PCR targeting the homologue of IS1001. Of 11 319 nasopharyngeal swabs, 2804 were collected from Finnish patients from 2000 to 2003, and 8515 from Dutch patients from 1992 to 2003. B. holmesii DNA was not found in the samples analysed. The results suggest that B. holmesii is not among the causative agents of pertussis-like symptoms in Finnish and Dutch patients and thus does not in practice confound IS481 and IS1001 PCRs.
-
-
-
Rapid cost-effective subtyping of meticillin-resistant Staphylococcus aureus by denaturing HPLC
More LessThe importance of meticillin-resistant Staphylococcus aureus (MRSA) in hospital-acquired infection is widely acknowledged. The UK government has stated that MRSA bloodstream infection rates will have to be halved by 2008. Such radical improvements will require advances on several fronts. Screening for MRSA in high-risk patients on arrival at hospital allows isolation of carriers and reduces transmission to staff and other patients. Concurrent subtyping of MRSA could also inform outbreak investigations and long-term epidemiological studies. The variability within the staphylococcal protein A, or spaA, gene-repeat region can be used as a marker of short- and long-term genetic variation. A novel application is described of denaturing HPLC (DHPLC) for rapid, inexpensive characterization of spaA gene amplification products, without the need for DNA sequence determination. The method allowed rapid and precise sizing of spaA gene-repeat regions from 99 S. aureus strains and was combined with heteroduplex analysis, using reference PCR products, to indicate the spa type of the test isolate. The method allowed subtyping of strains in less than 5 h from receipt of a primary isolation plate. When applied to an outbreak that occurred during this study, the authors were able to demonstrate relatedness of the isolates more than 5 days before results were received from a reference laboratory. If combined with direct amplification from swabs, DHPLC analysis of spaA gene variation could prove extremely valuable in outbreak investigation and MRSA surveillance.
-
-
-
Genotyping of Campylobacter jejuni using seven single-nucleotide polymorphisms in combination with flaA short variable region sequencing
This investigation describes the development of a generally applicable, bioinformatics-driven, single-nucleotide polymorphism (SNP) genotyping assay for the common bacterial gastrointestinal pathogen Campylobacter jejuni. SNPs were identified in silico using the program ‘Minimum SNPs’, which selects for polymorphisms providing the greatest resolution of bacterial populations based on Simpson's index of diversity (D). The high-D SNPs identified in this study were derived from the combined C. jejuni/Campylobacter coli multilocus sequence typing (MLST) database. Seven SNPs were found that provided a D of 0.98 compared with full MLST characterization, based on 959 sequence types (STs). The seven high-D SNPs were interrogated using allele-specific real-time PCR (AS kinetic PCR), which negates the need for expensive labelled primers or probes and requires minimal assay optimization. The total turnaround time of the SNP typing assay was approximately 2 h. Concurrently, 69 C. jejuni isolates were subjected to MLST and flagellin A short variable region (flaA SVR) sequencing and combined with a population of 84 C. jejuni and C. coli isolates previously characterized by these methods. Within this collection of 153 isolates, 19 flaA SVR types (D=0.857) were identified, compared with 40 different STs (D=0.939). When MLST and flaA SVR sequencing were used in combination, the discriminatory power was increased to 0.959. In comparison, SNP typing of the 153 isolates alone provided a D of 0.920 and was unable to resolve a small number of unrelated isolates. However, addition of the flaA SVR locus to the SNP typing procedure increased the resolving power to 0.952 and clustered isolates similarly to MLST/flaA SVR. This investigation has shown that a seven-member C. jejuni SNP typing assay, used in combination with sequencing of the flaA SVR, efficiently discriminates C. jejuni isolates.
-
-
-
Identification of a repetitive sequence belonging to a PPE gene of Mycobacterium tuberculosis and its use in diagnosis of tuberculosis
More LessA repetitive sequence specific to Mycobacterium tuberculosis was isolated from a λgt11 library of M. tuberculosis by DNA–DNA hybridization using genomic DNA of M. tuberculosis as probe followed by subtractive hybridization with a cocktail of other mycobacterial DNA. This led to identification of CD192, a 1291 bp fragment of M. tuberculosis containing repetitive sequences, which produced positive hybridization signals with M. tuberculosis DNA within 30 min. Nucleotide sequencing revealed the presence of several direct and inverted repeats within the 1291 bp fragment that belonged to a PPE family gene (Rv0355) of M. tuberculosis. The use of CD192 as a DNA probe for the identification of M. tuberculosis in culture and clinical samples was investigated. The 1291 bp sequence was present in M. tuberculosis, Mycobacterium bovis and M. bovis BCG, but was not present in many of the other mycobacterial strains tested, including M. tuberculosis H37Ra. More than 300 clinical isolates of M. tuberculosis were probed with CD192, and the presence of the 1291 bp sequence was observed in all the clinical strains, including those lacking IS6110. The sequence displayed RFLP among the clinical isolates. A PCR assay was developed which detected M. tuberculosis with 100 % specificity from specimens of sputum, cerebrospinal fluid and pleural effusion from clinically diagnosed cases of tuberculosis.
-
-
-
Pneumococci causing invasive disease in children prior to the introduction of pneumococcal conjugate vaccine in Scotland
This study aimed to determine the serotypes and sequence types (STs) of pneumococci causing paediatric invasive disease in Scotland prior to the introduction of pneumococcal conjugate vaccines (PCVs). All invasive pneumococci isolated between 2000 and 2004 from children aged less than 5 years in Scotland were used. The isolates were characterized by serotyping and multi-locus sequence typing. Two hundred and seventeen pneumococci were characterized into 22 different serogroups/types, the most common, in rank order, being 14, 19F, 6B, 18C, 23F, 9V, 4, 1, 19A and 6A. They were further genotyped into 77 different STs, the three most common being 9, 162 and 176. Common serotypes possessed multiple STs, but pneumococci of a particular clone were mostly associated with a particular serotype. The seven most common serotypes are included in the 7-valent polysaccharide conjugate vaccine (PCV7). Serotype coverage for PCV7 was 76.5 % in those aged less than 5 years but increased to 88.9 % for those aged 1 year. The introduction of PCV7 into the childhood immunization schedule would reduce the burden of pneumococcal disease in children, although continued surveillance of invasive pneumococcal disease will be required before, during and after the introduction of PCVs.
-
-
-
Development of a diagnostic test for the Midlands 1 cystic fibrosis epidemic strain of Pseudomonas aeruginosa
In a previous study of isolates from cystic fibrosis (CF) patients in England and Wales, the Midlands 1 strain of Pseudomonas aeruginosa was identified as the second most common clone, representing 10 % of isolates and found in nearly one-third of all CF centres [ Scott, F. W. & Pitt, T. L. (2004) . J Med Microbiol 53, 609–615]. Using suppression subtractive hybridization, 54 sequences were identified as present in a Midlands 1 strain but were absent from strain PAO1. The distribution of 14 of these sequences amongst representatives of Midlands 1, other CF epidemic strains and unrelated P. aeruginosa CF isolates was determined using PCR assays. Using these data, a PCR-based test was developed that was specific for the Midlands 1 clone, which was confirmed using dot-blot hybridization. By applying the test to CF isolates from a CF centre in Liverpool, a Midlands 1 clone was identified. The identity was confirmed using typing by PFGE. The PCR test should facilitate a greater understanding of the distribution of the Midlands 1 strain in the UK and elsewhere.
-
- Antimicrobial Agents And Chemotherapy
-
-
-
Role of the ABC transporter TruMDR2 in terbinafine, 4-nitroquinoline N-oxide and ethidium bromide susceptibility in Trichophyton rubrum
More LessA single-copy gene, designated TruMDR2, encoding an ATP-binding cassette (ABC) transporter was cloned and sequenced from the dermatophyte Trichophyton rubrum. The ORF of TruMDR2 was 4048 nt and the deduced amino acid sequence showed high homology with ABC transporters involved in drug efflux in other fungi. The encoded ABC protein predicted 12 transmembrane segments (TMSs) and two almost identical nucleotide-binding domains (NBDs) arranged in two halves in a (TMS6–NBD)2 configuration and could be classified as a member of the multidrug-resistance (MDR) class of ABC transporters. Northern blot analyses revealed an increased level of transcription of the TruMDR2 gene when mycelium was exposed to acriflavine, benomyl, ethidium bromide, ketoconazole, chloramphenicol, griseofulvin, fluconazole, imazalil, itraconazole, methotrexate, 4-nitroquinoline N-oxide (4NQO) or tioconazole. Disruption of the TruMDR2 gene rendered the mutant more sensitive to terbinafine, 4NQO and ethidium bromide than the control strain, suggesting that this transporter plays a role in modulating drug susceptibility in T. rubrum.
-
-
- Epidemiology
-
-
-
Epidemiological analysis of group A streptococci recovered from patients in China
More LessSince the mid-1980s, there has been a resurgence of severe forms of invasive group A streptococcal (GAS) disease in many countries and regions. However, there has not been any systemic epidemiologic analysis of GAS disease reported in mainland China. To analyse the molecular epidemiology of GAS disease, 86 strains from patients in different regions of mainland China were collected. The collection sites included blood, pus, wounds, the epipharynx and other sites. A total of 21 different emm types were identified in the isolates. In both invasive and non-invasive isolates, M1 (29.1 %) and M12 (23.3 %) were the most prevalent types, a different distribution to M type distributions reported in other countries. Furthermore, minor emm gene sequence alterations were noted for six types. Several important GAS virulence factors were detected by PCR using specific primers. The speB and slo genes were detected in all isolates and were species specific. Four superantigen genes, speA, speC, smeZ and ssa, were found in 52 % (45/86), 51 % (44/86), 82 % (71/86) and 23 % (27/86) of isolates, respectively. M1 isolates harboured more speA (84 %) and fewer speC genes (44 %), while M12 isolates had fewer speA (35 %) and more speC genes (100 %). There was also an association between some virulence genes and isolation sites, perhaps due to the correlation between the emm type distribution and virulence gene occurrence. For two important virulence genes related to necrotizing fasciitis, the sil gene was only carried by 11 of 86 isolates, and no sil gene contained the start codon ATA. The sla gene rarely occurred in GAS isolates, only four of 86 GAS strains being positive, including two isolates obtained from blood. In antimicrobial susceptibility tests, the overall rate of drug resistance in GAS isolates was higher than reported rates in other countries, and the resistance rates to erythromycin, tetracycline and clindamycin were 91.8, 93.4 and 80 %, respectively. This epidemiological study may help to understand the pathogenesis of GAS disease and aid in vaccine development.
-
-
-
-
Surveillance of invasive Streptococcus pneumoniae in Taiwan, 2002–2003
A total of 522 Streptococcus pneumoniae invasive isolates from diverse sources were collected from January 2002 to December 2003 in Taiwan in order to understand the serotype distribution of invasive isolates in Taiwan. The most frequently isolated serotypes of S. pneumoniae were types 14 (18.4 %), 23F (15.1 %), 3 (13.8 %), 19F (13.4 %), 6B (8.2 %), 9V (3.6 %) and 4 (2.5 %). The majority of cases were either under 5 years of age (24.1 %) or older than 65 years (36.6 %). Serotype distribution in adults aged over 14 years and children aged under 2 years was similar, except for that of type 3, which was more prevalent in adults. Penicillin-non-susceptible strains accounted for 67.7 % of all strains and were the predominant strains of serotypes 23F, 19F, 6B and 14. Most strains were susceptible to cephem drug, 85.7 % of isolates were susceptible to cefotaxime and 92.9 % were susceptible to ceftriaxone. A total of 72.6 % (379/522) of the isolates were resistant to at least two antibiotics. The 23-valent vaccine in the current commercial market would cover 87.2 % of the serotypes and 100 % of the penicillin-non-susceptible serotypes of S. pneumoniae in Taiwan. The coverage of 7- and 11-valent protein conjugate vaccines of the serotypes in children under 2 years of age would be 78.8 and 86.5 %, respectively. These results will help to assess the adequacy of the vaccine formulations marketed in Taiwan.
-
-
-
Superantigen gene profile, emm type and antibiotic resistance genes among group A streptococcal isolates from Barcelona, Spain
Group A streptococcus (GAS) has been described as an emerging cause of severe invasive infections. A retrospective hospital-based study was conducted, including GAS isolates causing invasive or non-invasive infections from January 1999 to June 2003 in Barcelona. Demographic and clinical information on the invasive cases was obtained from medical files. GAS isolates collected from 27 patients with invasive infections and 99 patients with non-invasive infections were characterized by emm type and subtype, superantigen (SAg) gene profile (speA–C, speF–J, speL, speM, ssa and smeZ), allelic variants of speA and smeZ genes, antibiotic susceptibility and genetic resistance determinants. The most prevalent emm type was emm1 (17.5 %), followed by emm3 (8.7 %), emm4 (8.7 %), emm12 (7.1 %) and emm28 (7.1 %). The smeZ allele and SAg gene profiles were closely associated with the emm type. The speA2, speA3 and speA4 alleles were found in emm1, emm3 and emm6 isolates, respectively. Overall, 27.8, 25.4 and 11.9 % of isolates were resistant to erythromycin, tetracycline or both agents, respectively. Reduced susceptibility to ciprofloxacin and levofloxacin (MIC 2–4 μg ml−1) was found in 3.2 % of isolates. mef(A)-positive emm types 4, 12 and 75, and erm(B)-positive emm types 11 and 25 were responsible for up to 80 % of the erythromycin-resistant isolates. No significant differences in emm-type distribution, SAg gene profile or resistance rates were found between invasive and non-invasive isolates. The SAg and antibiotic resistance genes appeared to be associated with the emm type and were independent of the disease type.
-
Volumes and issues
-
Volume 73 (2024)
-
Volume 72 (2023 - 2024)
-
Volume 71 (2022)
-
Volume 70 (2021)
-
Volume 69 (2020)
-
Volume 68 (2019)
-
Volume 67 (2018)
-
Volume 66 (2017)
-
Volume 65 (2016)
-
Volume 64 (2015)
-
Volume 63 (2014)
-
Volume 62 (2013)
-
Volume 61 (2012)
-
Volume 60 (2011)
-
Volume 59 (2010)
-
Volume 58 (2009)
-
Volume 57 (2008)
-
Volume 56 (2007)
-
Volume 55 (2006)
-
Volume 54 (2005)
-
Volume 53 (2004)
-
Volume 52 (2003)
-
Volume 51 (2002)
-
Volume 50 (2001)
-
Volume 49 (2000)
-
Volume 48 (1999)
-
Volume 47 (1998)
-
Volume 46 (1997)
-
Volume 45 (1996)
-
Volume 44 (1996)
-
Volume 43 (1995)
-
Volume 42 (1995)
-
Volume 41 (1994)
-
Volume 40 (1994)
-
Volume 39 (1993)
-
Volume 38 (1993)
-
Volume 37 (1992)
-
Volume 36 (1992)
-
Volume 35 (1991)
-
Volume 34 (1991)
-
Volume 33 (1990)
-
Volume 32 (1990)
-
Volume 31 (1990)
-
Volume 30 (1989)
-
Volume 29 (1989)
-
Volume 28 (1989)
-
Volume 27 (1988)
-
Volume 26 (1988)
-
Volume 25 (1988)
-
Volume 24 (1987)
-
Volume 23 (1987)
-
Volume 22 (1986)
-
Volume 21 (1986)
-
Volume 20 (1985)
-
Volume 19 (1985)
-
Volume 18 (1984)
-
Volume 17 (1984)
-
Volume 16 (1983)
-
Volume 15 (1982)
-
Volume 14 (1981)
-
Volume 13 (1980)
-
Volume 12 (1979)
-
Volume 11 (1978)
-
Volume 10 (1977)
-
Volume 9 (1976)
-
Volume 8 (1975)
-
Volume 7 (1974)
-
Volume 6 (1973)
-
Volume 5 (1972)
-
Volume 4 (1971)
-
Volume 3 (1970)
-
Volume 2 (1969)
-
Volume 1 (1968)