RESUMEN
PURPOSE: Streptococcus pyogenes (mostly termed group A Streptococcus - GAS) is the most important bacterial causative of pharyngitis. However, epidemiology of GAS pharyngitis is not widely established. This study describes GAS pharyngitis cases and emm-type distribution in a prospective study covering over 2 years in two Hospital Districts in Finland. METHODS: A prospective, systematic collection of GAS pharyngitis isolates was conducted between March 2018 and December 2020 in two large Hospital Districts in Finland. Patient characteristics (age, gender) were included if available. All GAS isolates collected were emm typed. RESULTS: Altogether 1320 GAS pharyngitis strains were collected, 904 in the Hospital District 1 (HD1) and 416 in Hospital District 2 (HD2). In HD1, age and gender data were available. Females were overrepresented (58% of all cases). In addition, the age and gender distributions were noted to be significantly different (p < 0.0001) with females having a more uniform distribution until age of 40. emm28 was common among the age group of 20-29-year-olds and emm89 in children under 10 years of age, respectively. In HD1, most of the isolates were collected during winter and autumn months. Significant differences by season in the frequency of emm12, emm89, emm75 and group of "others" were observed. CONCLUSION: Age distribution among GAS pharyngitis cases was significantly different between genders (p < 0.0001). In addition, age group specific and seasonal variations in emm GAS types causing the disease were observed. These findings warrant further investigation, especially for understanding population-based spread of GAS even in more detail.
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Faringitis , Infecciones Estreptocócicas , Niño , Humanos , Femenino , Masculino , Adulto Joven , Adulto , Streptococcus pyogenes , Estudios Prospectivos , Finlandia/epidemiología , Antígenos Bacterianos/genética , Proteínas de la Membrana Bacteriana Externa/genética , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Proteínas Portadoras/genética , Faringitis/epidemiología , Faringitis/microbiología , GenotipoRESUMEN
BackgroundInvasive infections with beta-haemolytic streptococci of Lancefield groups A (iGAS), B (iGBS) and C/G (iGCGS) are a major cause of morbidity and mortality worldwide.AimWe studied incidence trends of invasive beta-haemolytic streptococcal infections in Finland, focusing on iGCGS.MethodsWe conducted a retrospective register-based study. Cases were defined as isolations from blood and/or cerebrospinal fluid and retrieved from the National Infectious Disease Register where all invasive cases are mandatorily notified.ResultsBetween 2006 and 2020, the mean annual incidence was 4.1 per 100,000 for iGAS (range:â¯2.1-6.7), 5.2 for iGBS (4.0-6.3) and 10.1 for iGCGS (5.4-17.6). The incidence displayed an increasing trend for all groups, albeit for iGBS only for individuals 45 years and older. The increase was particularly sharp for iGCGS (8% annual relative increase). The incidence rate was higher in males for iGCGS (adjusted incidence rate ratio (IRR) = 1.6; 95%â¯confidence interval (CI): 1.5-1.8) and iGAS (adjusted IRR = 1.3; 95%â¯CI: 1.1-1.4); for iGBS, the association with sex was age-dependent. In adults, iGCGS incidence increased significantly with age. Recurrency was seen for iGCGS and secondarily iGBS, but not for iGAS. Infections with iGCGS and iGBS peaked in July and August.ConclusionsThe incidence of invasive beta-haemolytic streptococcal infections in Finland has been rising since 2006, especially for iGCGS and among the elderly population. However, national surveillance still focuses on iGAS and iGBS, and European Union-wide surveillance is lacking. We recommend that surveillance of iGCGS be enhanced, including systematic collection and typing of isolates, to guide infection prevention strategies.
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Infecciones Estreptocócicas , Streptococcus pyogenes , Adulto , Masculino , Humanos , Anciano , Infecciones Estreptocócicas/epidemiología , Finlandia/epidemiología , Estudios Retrospectivos , Recolección de Datos , IncidenciaRESUMEN
Streptococcus pyogenes, also called group A streptococcus (GAS), is a human pathogen causing a wide range of infections ranging from mild tonsillitis to severe, life threatening conditions such as bacteraemia, necrotizing fasciitis, and streptococcal toxic shock syndrome. GAS may also colonise the oropharynx without causing any signs of disease which is known as asymptomatic carriage. This study aims to investigate IgA responses against GAS and oral streptococci from saliva samples collected from healthy Finnish adults. In addition, asymptomatic throat GAS carriage was studied. The study participants consisted of healthy adult volunteers who provided one saliva sample, a throat swab, and a background questionnaire. Total salivary IgA, and GAS specific IgA were analysed from the saliva samples using enzyme-linked immunosorbent assays (ELISA) and the results were compared to oral streptococci specific IgA levels. Asymptomatic GAS throat carriers were identified by bacterial culture, and the isolates were emm typed. Samples from a total of 182 individuals were analysed. The median salivary IgA concentration was 62.9 µg/ml (range 17.3-649.9 µg/ml), and median GAS and oral streptococcal specific IgA concentrations 2.7 and 3.3 arbitrary units (AU, range 1.4-7.4 AU and 1.6-12.0 AU), respectively. Three individuals with asymptomatic GAS throat carriage were identified.
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Infecciones Estreptocócicas , Streptococcus pyogenes , Adulto , Humanos , Finlandia/epidemiología , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Inmunoglobulina A Secretora , Faringe/microbiologíaRESUMEN
Our aim was to study the detection of group A streptococcus (GAS) with different diagnostic methods in paediatric pharyngitis patients with and without a confirmed viral infection. In this prospective observational study, throat swabs and blood samples were collected from children (age 1-16 years) presenting to the emergency department with febrile pharyngitis. A confirmed viral infection was defined as a positive virus diagnostic test (nucleic acid amplification test [NAAT] and/or serology) together with an antiviral immune response of the host demonstrated by elevated (≥ 175 µg/L) myxovirus resistance protein A (MxA) blood concentration. Testing for GAS was performed by a throat culture, by 2 rapid antigen detection tests (StrepTop and mariPOC) and by 2 NAATs (Simplexa and Illumigene). Altogether, 83 children were recruited of whom 48 had samples available for GAS testing. Confirmed viral infection was diagnosed in 30/48 (63%) children with febrile pharyngitis. Enteroviruses 11/30 (37%), adenoviruses 9/30 (30%) and rhinoviruses 9/30 (30%) were the most common viruses detected. GAS was detected by throat culture in 5/30 (17%) with and in 6/18 (33%) patients without a confirmed viral infection. Respectively, GAS was detected in 4/30 (13%) and 6/18 (33%) by StrepTop, 13/30 (43%) and 10/18 (56%) by mariPOC, 6/30 (20%) and 9/18 (50%) by Simplexa, and 5/30 (17%) and 6/18 (30%) patients by Illumigene. CONCLUSION: GAS was frequently detected also in paediatric pharyngitis patients with a confirmed viral infection. The presence of antiviral host response and increased GAS detection by sensitive methods suggest incidental throat carriage of GAS in viral pharyngitis. WHAT IS KNOWN: â¢The frequency and significance of GAS-virus co-detection are poorly characterised in children with pharyngitis. â¢Detection of a virus and the antiviral host response likely indicates symptomatic infection. WHAT IS NEW: â¢Group A streptococcus (GAS) was detected in 17-43% of the children with confirmed viral pharyngitis depending on the GAS diagnostic method. â¢Our results emphasize the risk of detecting and treating incidental pharyngeal carriage of GAS in children with viral pharyngitis.
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Faringitis , Infecciones Estreptocócicas , Virosis , Humanos , Niño , Lactante , Preescolar , Adolescente , Antivirales/uso terapéutico , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/tratamiento farmacológico , Streptococcus pyogenes , Faringitis/diagnóstico , Fiebre , Inmunidad , Sensibilidad y EspecificidadRESUMEN
Recently, two related Streptococcus pyogenes strains with reduced susceptibility to ampicillin, amoxicillin, and cefotaxime, antibiotics commonly used to treat S. pyogenes infections, were reported. The two strains had the same nonsynonymous (amino acid-substituting) mutation in the pbp2x gene, encoding penicillin-binding protein 2X (PBP2X). This concerning report led us to investigate our library of 7,025 genome sequences of type emm1, emm28, and emm89S. pyogenes clinical strains recovered from intercontinental sources for mutations in pbp2x We identified 137 strains that, combined, had 37 nonsynonymous mutations in 36 codons in pbp2x Although to a lesser magnitude than the two previously published isolates, many of our strains had decreased susceptibility in vitro to multiple beta-lactam antibiotics. Many pbp2x mutations were found only in single strains, but 16 groups of two or more isolates of the same emm type had an identical amino acid replacement. Phylogenetic analysis showed that, with one exception, strains of the same emm type with the same amino acid replacement were clonally related by descent. This finding indicates that strains with some amino acid changes in PBP2X can successfully spread to new human hosts and cause invasive infections. Mapping of the amino acid changes onto a three-dimensional structure of the related Streptococcus pneumoniae PBP2X suggests that some substitutions are located in regions functionally important in related pathogenic bacterial species. Decreased beta-lactam susceptibility is geographically widespread in strains of numerically common emm gene subtypes. Enhanced surveillance and further epidemiological and molecular genetic study of this potential emergent antimicrobial problem are warranted.
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Streptococcus pyogenes , beta-Lactamas , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Humanos , Pruebas de Sensibilidad Microbiana , Mutación , Proteínas de Unión a las Penicilinas/genética , Filogenia , Streptococcus pyogenes/genética , beta-Lactamas/farmacologíaRESUMEN
The incidence of invasive group A streptococcal (GAS) infections has shown a fluctuating but increasing trend in Finland. The impact of infectious diseases specialist consultation (IDSC) on the antimicrobial therapy of GAS bacteremia has not been studied earlier. A retrospective study on adult GAS bacteremia in The Hospital District of Southwest Finland (HDSWF) was conducted from 2007 to 2018. Data on incidence of bacteremic GAS cases were gathered from the National Infectious Disease Register. Clinical data were obtained by reviewing the electronic patient records. The overall incidence of GAS bacteremia in HDSWF was 3.52/100,000, but year-to-year variation was observed with the highest incidence of 7.93/100,000 in 2018. A total of 212 adult GAS bacteremia cases were included. A record of IDSC was found (+) in 117 (55.2%) cases, not found (-) in 71 (33.5%) cases and data were not available in 24 (11.3%) cases. Among IDSC+ cases, 57.3% were on penicillin G treatment whereas in the group IDSC- only 22.5%, respectively (OR = 4.61, 95% CI 2.37-8.97; p < 0.001). The use of clindamycin as adjunctive antibiotic was more common among IDSC+ (54.7%) than IDSC- (21.7%) (OR = 4.51, 95% CI 2.29-8.87; p < 0.001). There was an increasing trend in incidence of GAS bacteremia during the study period. Narrow-spectrum beta-lactam antibiotics were chosen, and adjunctive clindamycin was more commonly used, if IDSC took place. This highlights the importance of availability of IDSC but calls for improved practice among infectious diseases specialists by avoiding combination therapy with clindamycin in non-severe invasive GAS infections.
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Antibacterianos/uso terapéutico , Bacteriemia/epidemiología , Bacteriemia/microbiología , Derivación y Consulta/estadística & datos numéricos , Infecciones Estreptocócicas/tratamiento farmacológico , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/aislamiento & purificación , Adulto , Anciano , Antibacterianos/farmacología , Bacteriemia/tratamiento farmacológico , Clindamicina/farmacología , Clindamicina/uso terapéutico , Farmacorresistencia Bacteriana , Quimioterapia Combinada , Femenino , Finlandia/epidemiología , Humanos , Incidencia , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Estudios Retrospectivos , Infecciones Estreptocócicas/epidemiología , Streptococcus/efectos de los fármacos , Streptococcus/aislamiento & purificación , Streptococcus pyogenes/efectos de los fármacos , beta-Lactamas/farmacología , beta-Lactamas/uso terapéuticoRESUMEN
The incidence of methicillin-resistant Staphylococcus aureus (MRSA) has increased sharply in Hospital District of Southwest Finland (HD). To understand reasons behind this, a retrospective, population-based study covering 10 years was conducted. All new 983 MRSA cases in HD from January 2007 to December 2016 were analysed. Several data sources were used to gather background information on the cases. MRSA cases were classified as healthcare-associated (HA-MRSA), community-associated (CA-MRSA), and livestock contact was determined (livestock-associated MRSA, LA-MRSA). Spa typing was performed to all available strains. The incidence of MRSA doubled from 12.4 to 24.9 cases/100000 persons/year. The proportion of clinical infections increased from 25 to 32% in the 5-year periods, respectively, (p < 0.05). The median age decreased from 61 years in 2007 to 30 years in 2016. HA-MRSA accounted for 68% of all cases, of which 32% associated with 26 healthcare outbreaks. The proportion of CA-MRSA cases increased from 13% in 2007 to 43% in 2016. Of CA-MRSA cases, 43% were among family clusters, 32% in immigrants and 4% were LA-MRSA. The Gini-Simpson diversity index for spa types increased from 0.86 to 0.95 from the first to the second 5-year period. The proportion of a predominant strain t172 decreased from 43% in 2009 to 7% in 2016. The rise in the proportion of CA-MRSA, the switch to younger age groups, the complexity of possible transmission routes and the growing spa-type diversity characterize our current MRSA landscape. This creates challenges for targeted infection control measures, demanding further studies.
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Infecciones Comunitarias Adquiridas/epidemiología , Infección Hospitalaria/epidemiología , Staphylococcus aureus Resistente a Meticilina/clasificación , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Portador Sano/epidemiología , Portador Sano/microbiología , Niño , Preescolar , Infecciones Comunitarias Adquiridas/microbiología , Infección Hospitalaria/microbiología , Femenino , Finlandia/epidemiología , Humanos , Lactante , Recién Nacido , Ganado/microbiología , Masculino , Staphylococcus aureus Resistente a Meticilina/genética , Persona de Mediana Edad , Epidemiología Molecular , Tipificación Molecular , Estudios Retrospectivos , Infecciones Estafilocócicas/microbiología , Adulto JovenRESUMEN
Pharyngeal tonsillitis is one of the most common upper respiratory tract infections, and group A streptococcus is the most important bacterial pathogen causing it. While most patients experience tonsillitis only rarely, a subset of patients suffers from recurrent or chronic tonsillitis or pharyngitis. The predisposing factors for recurring or chronic forms of this disease are not yet fully understood, but genetic predisposition has been suggested. A genetic association study using Illumina's Immunochip single-nucleotide polymorphism (SNP) array was performed to search for new genetic biomarkers in pharyngeal tonsillitis. More than 100,000 SNPs relevant to immune-mediated diseases were analyzed in a cohort of 95 patients subjected to tonsillectomy due to recurrent/chronic tonsillitis and 504 controls. Genetic association between the cases and controls showed strongest association with two peaks in the HLA locus (odds ratio [OR], 3.7 to 4.7; P = 4.9 × 10-6 to 5.7 × 10-6). Further analysis with imputed classical HLA alleles suggested the known psoriasis risk allele HLA-C*06:02 as a risk factor for tonsillitis (P = 4.8 × 10-4; OR, 2.3). In addition, the imputed HLA haplotype HLA-C*06:02/HLA-B*57:01, a reported risk haplotype in psoriasis, had the strongest risk for tonsillitis (P = 3.2 × 10-4; OR, 6.5). These findings further support the previously reported link between streptococcal throat infections and psoriasis.
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Antígenos HLA-C/genética , Psoriasis/genética , Infecciones Estreptocócicas/microbiología , Tonsilitis/microbiología , Alelos , Estudios de Casos y Controles , Enfermedad Crónica , Estudios de Cohortes , Femenino , Predisposición Genética a la Enfermedad , Antígenos HLA-C/inmunología , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Infecciones Estreptocócicas/genética , Infecciones Estreptocócicas/inmunología , Streptococcus pyogenes/fisiología , Tonsilectomía , Tonsilitis/genética , Tonsilitis/inmunologíaRESUMEN
The genetic distribution of invasive methicillin-susceptible (MSSA) and resistant S. aureus (MRSA) strains has to be addressed in order to target infection control strategies. A large MRSA epidemic caused by a certain MRSA strain (spa type 067) broke out in 2001 in our health district. We wanted to investigate the current spa type distribution in MRSA and MSSA bacteremias and assess the potential association of spa clonal complexes (spaCC) with the clinical characteristics of S. aureus bacteremia. One hundred nine invasive MRSA isolates and 353 invasive MSSA isolates were spa typed and grouped into clonal complexes (spaCC). Spa type distribution was compared to that of colonizing MRSA strains. Spa type and spaCC data linked to clinical information on the course of bacteremic cases was used to search for differences in virulence between strains. Spa type distribution in MRSA is less heterogenic than in MSSA. t067 dominates both in MRSA colonisations and in invasive findings. Among MSSA, no such dominating strains were found. Of spaCCs, mortality was the highest in spaCC 067 (25.6%). SpaCC 008 was more often associated with endocarditis than other CCs (22.7 vs 5.8%, p = 0.013), spaCC 2133 with skin infections (68.4 vs 36.4%, p = 0.007), and spaCC 012 with foreign body infections (25.0 vs 9.3%, p = 0.029) than other clonal complexes. A single successful strain can explain the major proportion of MRSA among S. aureus bacteremias. Certain spaCCs showed association with certain clinical characteristics. These findings suggest that S. aureus strains differ in their virulence and invasiveness.
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Bacteriemia/epidemiología , Bacteriemia/microbiología , Staphylococcus aureus Resistente a Meticilina/clasificación , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/clasificación , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Bacteriemia/diagnóstico , Bacteriemia/mortalidad , Técnicas de Tipificación Bacteriana , Femenino , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/genética , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Mortalidad , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/mortalidad , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética , Adulto JovenRESUMEN
We investigated the faecal carriage prevalence of extended-spectrum ß-lactamase production in Escherichia coli (EP-EC) and/or Klebsiella pneumoniae (EP-KP) and risk factors associated with carriage among adult study subjects in Finland, Germany, Latvia, Poland, Russia and Sweden (partner countries). The aim was to get indicative data on the prevalence of ESBL-carriage in specific populations in the region. Faecal samples were collected from four study populations and screened on ChromID-ESBL and ChromID-OXA-48 plates. Positive isolates were further characterised phenotypically. Our results show a large variation in carrier prevalence ranging from 1.6% in Latvia to 23.2% in Russia for EP-EC. For the other partner countries, the prevalence of EP-EC were in increasing numbers, 2.3% for Germany, 4.7% for Finland, 6.6% for Sweden, 8.0% for Poland and 8.1% for all partner countries in total. Carriers of EP-KP were identified only in Finland, Russia and Sweden, and the prevalence was < 2% in each of these countries. No carriers of carbapenemase-producing isolates were identified. This is the first study reporting prevalence of carriers (excluding traveller studies) for Finland, Latvia, Poland and Russia. It contributes with important information regarding the prevalence of EP-EC and EP-KP carriage in regions where studies on carriers are limited.
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Infecciones Asintomáticas/epidemiología , Infecciones por Escherichia coli/epidemiología , Escherichia coli/aislamiento & purificación , Heces/microbiología , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/aislamiento & purificación , Adulto , Antibacterianos/farmacología , Proteínas Bacterianas/metabolismo , Estudios Transversales , Farmacorresistencia Bacteriana Múltiple , Escherichia coli/enzimología , Europa (Continente)/epidemiología , Femenino , Humanos , Klebsiella pneumoniae/enzimología , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Federación de Rusia/epidemiología , Adulto Joven , beta-Lactamasas/metabolismoRESUMEN
We sequenced the genomes of 3,615 strains of serotype Emm protein 1 (M1) group A Streptococcus to unravel the nature and timing of molecular events contributing to the emergence, dissemination, and genetic diversification of an unusually virulent clone that now causes epidemic human infections worldwide. We discovered that the contemporary epidemic clone emerged in stepwise fashion from a precursor cell that first contained the phage encoding an extracellular DNase virulence factor (streptococcal DNase D2, SdaD2) and subsequently acquired the phage encoding the SpeA1 variant of the streptococcal pyrogenic exotoxin A superantigen. The SpeA2 toxin variant evolved from SpeA1 by a single-nucleotide change in the M1 progenitor strain before acquisition by horizontal gene transfer of a large chromosomal region encoding secreted toxins NAD(+)-glycohydrolase and streptolysin O. Acquisition of this 36-kb region in the early 1980s into just one cell containing the phage-encoded sdaD2 and speA2 genes was the final major molecular event preceding the emergence and rapid intercontinental spread of the contemporary epidemic clone. Thus, we resolve a decades-old controversy about the type and sequence of genomic alterations that produced this explosive epidemic. Analysis of comprehensive, population-based contemporary invasive strains from seven countries identified strong patterns of temporal population structure. Compared with a preepidemic reference strain, the contemporary clone is significantly more virulent in nonhuman primate models of pharyngitis and necrotizing fasciitis. A key finding is that the molecular evolutionary events transpiring in just one bacterial cell ultimately have produced millions of human infections worldwide.
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Epidemias , Evolución Molecular , Genoma Bacteriano/genética , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/genética , Streptococcus pyogenes/genética , Streptococcus pyogenes/patogenicidad , Animales , Secuencia de Bases , Modelos Animales de Enfermedad , Fascitis Necrotizante/epidemiología , Fascitis Necrotizante/genética , Fascitis Necrotizante/microbiología , Finlandia/epidemiología , Genes Bacterianos/genética , Genómica , Humanos , Mutación INDEL/genética , Faringitis/epidemiología , Faringitis/genética , Faringitis/microbiología , Polimorfismo de Nucleótido Simple/genética , Primates/microbiología , Selección Genética , Serotipificación , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/aislamiento & purificación , Factores de Tiempo , Virulencia/genéticaRESUMEN
BACKGROUND: Many countries worldwide have reported increasing numbers of emm89 group A Streptococcus (GAS) infections during last decade. Pathogen genetic factors linked to this increase need assessment. METHODS: We investigated epidemiological characteristics of emm89 GAS bacteremic infections, including 7-day and 30-day case-fatality rates, in Finland during 2004-2014 and linked them to whole-genome sequencing data obtained from corresponding strains. The Fisher exact test and exact logistic regression were used to compare differences between bacteremic infections due to emm89 GAS belonging to different genetic clades and subclades. RESULTS: Out of 1928 cases of GAS bacteremic infection, 278 were caused by emm89 GAS. We identified 2 genetically distinct clades, arbitrarily designated clade 2 and clade 3. Both clades were present during 2004-2008, but clade 3 increased rapidly from 2009 onward. Six subclades (designated subclades A-F) were identified within clade 3, based on phylogenetic core genome analysis. The case-fatality rate differed significantly between subclades (P < .05), with subclade D having the highest 30-day estimated case-fatality rate (19% vs 3%-14%). CONCLUSIONS: A new emm89 clone, clade 3, emerged in 2009 and spread rapidly in Finland. Patients infected with certain subclades of clade 3 were significantly more likely to die. A specific polymerase chain reaction assay was developed to follow the spread of subclade D in 2015.
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Bacteriemia/epidemiología , Bacteriemia/microbiología , Genotipo , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/clasificación , Streptococcus pyogenes/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antígenos Bacterianos/genética , Bacteriemia/mortalidad , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas Portadoras/genética , Niño , Preescolar , Análisis por Conglomerados , Femenino , Finlandia/epidemiología , Genoma Bacteriano , Genómica , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Técnicas de Diagnóstico Molecular/métodos , Epidemiología Molecular/métodos , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Infecciones Estreptocócicas/mortalidad , Streptococcus pyogenes/aislamiento & purificación , Análisis de Supervivencia , Adulto JovenRESUMEN
Streptococcus pyogenes (or group A streptococcus [GAS]) is a major human pathogen causing infections, such as tonsillitis, erysipelas, and sepsis. Several GAS strains bind host complement regulator factor H (CFH) via its domain 7 and, thereby, evade complement attack and C3b-mediated opsonophagocytosis. Importance of CFH binding for survival of GAS has been poorly studied because removal of CFH from plasma or blood causes vigorous complement activation, and specific inhibitors of the interaction have not been available. In this study, we found that activation of human complement by different GAS strains (n = 38) correlated negatively with binding of CFH via its domains 5-7. The importance of acquisition of host CFH for survival of GAS in vitro was studied next by blocking the binding with recombinant CFH5-7 lacking the regulatory domains 1-4. Using this fragment in full human blood resulted in death or radically reduced multiplication of all of the studied CFH-binding GAS strains. To study the importance of CFH binding in vivo (i.e., for pathogenesis of streptococcal infections), we used our recent finding that GAS binding to CFH is diminished in vitro by polymorphism 402H, which is also associated with age-related macular degeneration. We showed that allele 402H is suggested to be associated with protection from erysipelas (n = 278) and streptococcal tonsillitis (n = 209) compared with controls (n = 455) (p < 0.05). Taken together, the bacterial in vitro survival data and human genetic association revealed that binding of CFH is important for pathogenesis of GAS infections and suggested that inhibition of CFH binding can be a novel therapeutic approach in GAS infections.
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Activación de Complemento , Polimorfismo de Nucleótido Simple/inmunología , Infecciones Estreptocócicas , Streptococcus pyogenes/inmunología , Streptococcus pyogenes/patogenicidad , Activación de Complemento/genética , Activación de Complemento/inmunología , Factor H de Complemento/genética , Factor H de Complemento/inmunología , Erisipela/genética , Erisipela/inmunología , Erisipela/microbiología , Estudio de Asociación del Genoma Completo , Humanos , Degeneración Macular/genética , Degeneración Macular/inmunología , Estructura Terciaria de Proteína , Infecciones Estreptocócicas/genética , Infecciones Estreptocócicas/inmunología , Tonsilitis/genética , Tonsilitis/inmunología , Tonsilitis/microbiologíaRESUMEN
BACKGROUND: Pulsed-field gel electrophoresis (PFGE) is the main typing method used for the molecular typing of vancomycin-resistant Enterococcus faecium (VREfm). However, more rapid and unambiguous typing methods are needed. DiversiLab, a repetitive sequence-based PCR (rep-PCR), offers an alternative method for strain typing. METHODS: Thirty-nine VREfm isolates with known epidemiological relationships were characterized by semi-automated rep-PCR (DiversiLab), PFGE, and multilocus sequence typing (MLST). RESULTS: The DiversiLab results were analysed in 2 ways: first relying solely on the DiversiLab software, and second by DiversiLab analysis combined with manual interpretation. The analysis with interpretation yielded more DiversiLab profiles, correlated better with PFGE and MLST, and grouped the isolates better according to their relatedness in time and space. However, most of the DiversiLab groups also included isolates with different PFGE and MLST types. CONCLUSIONS: DiversiLab provides rapid information when investigating a potential hospital outbreak. However, the interpretation of E. faecium DiversiLab results cannot be fully automated and is not always straightforward. Other typing methods may be necessary to confirm the analysis.
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Electroforesis en Gel de Campo Pulsado/métodos , Enterococcus faecium/clasificación , Infecciones por Bacterias Grampositivas/microbiología , Tipificación de Secuencias Multilocus/métodos , Reacción en Cadena de la Polimerasa/métodos , Farmacorresistencia Microbiana , Enterococcus faecium/genética , Enterococcus faecium/aislamiento & purificación , Humanos , Vancomicina/farmacologíaRESUMEN
BACKGROUND: We present here the first application of 2-photon excited fluorescence detection (TPX) technology for the direct screening of clinical colonization samples for methicillin-resistant Staphylococcus aureus (MRSA). METHODS: A total of 125 samples from 14 patients with previously identified MRSA carriage and 16 controls from low-prevalence settings were examined. RESULTS: The results were compared to those obtained by both standard phenotypic and molecular methods. In identifying MRSA carriers, i.e. persons with at least 1 MRSA positive colonization sample by standard methods, the sensitivity of the TPX technique was 100%, the specificity 78%, the positive predictive value 75%, and the negative predictive value 100%. The TPX assay sensitivity per colonization sample was 89%, the specificity 93%, the positive predictive value 84%, and the negative predictive value 95%. The median time for a true-positive test result was 3 h and 26 min; negative test results are available after 13 h. The assay capacity was 48 samples per test run. CONCLUSIONS: The TPX MRSA technique could provide early preliminary results for clinicians, while simultaneously functioning as a selective enrichment step for further conventional testing. Costs and workload associated with hospital infection control can be reduced using this high-throughput, point-of-care compatible methodology.
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Portador Sano/microbiología , Ensayos Analíticos de Alto Rendimiento/métodos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/microbiología , Portador Sano/diagnóstico , Técnica del Anticuerpo Fluorescente/métodos , Ingle/microbiología , Humanos , Cavidad Nasal/microbiología , Perineo/microbiología , Sensibilidad y Especificidad , Infecciones Estafilocócicas/diagnósticoRESUMEN
BACKGROUND: The incidence of methicillin-resistant Staphylococcus aureus (MRSA) has been low in the Scandinavian countries, including Finland. METHODS: We report a population-based, prospective survey of an exceptionally large ongoing MRSA epidemic in a Finnish health district (HD), Pirkanmaa HD, during 2001-2011 caused by 1 strain, spa t067 (FIN-16). RESULTS: The first FIN-16 case in the HD was identified in 2000. Ten years later, 2447 carriers had been found in 95 different institutions. MRSA in carriers was mostly health care-associated (98%). The epidemic emerged in long-term care facilities and gradually spread to acute hospitals. The majority of carriers were elderly people (median age 78 y). Fifty-two percent of new carriers had an infection with MRSA at the time of detection. CONCLUSIONS: The incidence of MRSA in Pirkanmaa HD is substantially higher than the incidence for all of Finland. Temporary projects to control MRSA have not proved sufficient to contain this large epidemic.
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Epidemias , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Distribución de Chi-Cuadrado , Niño , Preescolar , Femenino , Finlandia/epidemiología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
OBJECTIVES: Antimicrobial resistance (AMR) is a global concern among infectious diseases. Bloodstream infections can potentially become life-threatening if they become untreatable with conventional antimicrobials. This review aims to provide an understanding of the AMR prevalence and trends of common bacteremic pathogens, namely Escherichia coli and Staphylococcus aureus in the World Health Organization (WHO) Africa region. METHODS: PubMed and Google Scholar were searched using relevant keywords for published human studies (excluding case reports and reviews) reporting bacteremic AMR data on the pathogens of interest between 2008 and 2019. Two reviewers independently screened the articles against a pre-defined eligibility criterion. Data extraction and analysis were achieved with different platforms: Covidence, Excel, R version 3.6.3, and QGIS v3.4.5. The pooled prevalence, 95% confidence intervals, and I2 index (a measure of heterogeneity) were calculated for the various pathogen-antibiotic combinations. RESULTS: Five hundred sixty-two papers were retrieved, with 27 papers included in the final analysis. Only 23.4% (11/47) of member states of the WHO African region had reports on AMR in bacteremia. The Clinical and Laboratory Standards Institute (CLSI) (78.5%) was the most common standard used in the region. For E. coli, the pooled resistance was: cefotaxime (42%), imipenem (4%), meropenem (0%), and colistin (0%). For S. aureus, the calculated pooled resistance was cloxacillin (34%), oxacillin (12%), and vancomycin (0%). There was a high degree of variation across studies (I2 > 90%). CONCLUSION: The pooled resistance rates indicate a concerning degree of methicillin-resistant and Extended Spectrum-ß-lactamase-producing pathogens. The paucity of AMR data also presents challenges for a comprehensive understanding of the situation in the region. Continent-wide and standardized surveillance efforts therefore need strengthening.
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Bacteriemia , Infecciones Estafilocócicas , Humanos , Staphylococcus aureus , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Escherichia coli , Prevalencia , Farmacorresistencia Bacteriana , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/tratamiento farmacológico , Bacteriemia/epidemiología , Bacteriemia/tratamiento farmacológico , África/epidemiologíaRESUMEN
PURPOSE: Streptococcus pyogenes (Group A Streptococcus, GAS) is an important human pathogen that can cause severe invasive (iGAS) infections. Throat carriage has been assumed to possibly lead to hematogenous seeding. Retrospective studies may estimate the incidence of throat carriage in iGAS patients inaccurately. In this study we aimed to gather data on the presence of GAS in the throat among iGAS patients in a prospective setting. METHODS: We conducted a prospective clinical study covering iGAS infections in adult patients in two university hospitals in Finland from June 2018 to July 2020. Recruited patients' throats were swabbed for culture and isothermal amplification tests (IAT) to search for GAS. The study was registered at ClinicalTrials.gov as ID NCT03507101. RESULTS: We enrolled 45 patients. Throat swabs were obtained from 39/45 (87%) patients. Ten patients (22%) had a positive IAT for GAS. They were statistically significantly more likely to be male (9/10 [90%] vs 13/29 [45%], p = .024). Several different emm types caused the iGAS infections. CONCLUSIONS: GAS was frequently observed in throat swabs of patients with iGAS infection. This may suggest that hematogenous seeding from the nasopharynx is a possible portal of entry.
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Infecciones Estreptocócicas , Streptococcus pyogenes , Adulto , Femenino , Humanos , Masculino , Finlandia/epidemiología , Faringe , Estudios Prospectivos , Estudios Retrospectivos , Infecciones Estreptocócicas/epidemiologíaRESUMEN
BACKGROUND: A ubiquitous human pathogen, Streptococcus pyogenes (Group A Streptococcus, GAS) causes infections from mild pharyngitis to severe septic infections. Acute kidney injury (AKI) is a condition of prompt decline of renal function. The aim of the present study was to report the incidence and outcome of AKI in GAS bacteraemia and to evaluate the diagnostic value of serum C-reactive protein as an indicator of AKI. METHODS: All adult patients with GAS bacteraemia treated at Turku University Hospital from 2007 to 2018 were identified and their patient records were scrutinised. RESULTS: Of 195 included patients, 38 (19.5%) had AKI stage 1, 20 (10.3%) AKI stage 2 and 26 (13.3%) AKI stage 3 and 111 (56.9%) did not have AKI. The adjusted seven-day mortality was significantly higher in AKI stages 2 and 3 compared to the non-AKI group (15% and 19% vs. 3.6%; p = .046 and .006, respectively). Of the survivors, 95.8% met the criteria of renal recovery at discharge. The higher the AKI stage, the higher was the mean serum CRP level on admission. The optimal cut-off for CRP to identify patients with AKI stage 2 or 3 was ≥244 mg/l (sensitivity 82.6% and specificity 75.8%). CONCLUSIONS: AKI is common in patients with GAS bacteraemia and the severity of AKI correlates with the CRP level on admission. The mortality of patients with GAS bacteraemia and AKI is significantly higher than of patients without AKI. Most survivors, however, show renal recovery.Key MessageAKI is common in group A Streptococcal bacteraemia and increases mortality compared to bacteraemia alone. However, renal recovery is also common. A high CRP level on admission correlates significantly positively with the degree of severity of AKI.
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Lesión Renal Aguda , Bacteriemia , Adulto , Humanos , Proteína C-Reactiva/análisis , Incidencia , Streptococcus pyogenes , Estudios Retrospectivos , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/diagnóstico , Bacteriemia/complicaciones , Bacteriemia/epidemiología , Factores de RiesgoRESUMEN
Methicillin-resistant Staphylococcus aureus (MRSA) rates have remained relatively low in Finland. In Southwest Finland, however, annual MRSA incidence increased from 12 to 25/100,000 between 2007 and 2016 with spa t172 strain causing one fourth (237/983) of all cases. This provoked us to study the molecular epidemiology of t172-MRSA, aiming to better understand the transmission of this strain type. We combined epidemiological data and whole genome sequencing (WGS) of a set of 64 (27%, 64/237) t172-MRSA isolates covering 10 years. Isolates represented sporadic and index cases of all identified healthcare-associated outbreaks (HAOs) and family clusters (FCs). Among the included 62 isolates, core-genome MLST analysis revealed eight genomic clusters comprising 24 (38.7%) isolates and 38 (61.3%) non-clustered isolates. Cluster 1 comprised ten and the remaining seven clusters two isolates each, respectively. Two epidemiologically distinct HAOs were linked in cluster 1. FCs were involved in all clusters. All strains were associated with epidemic clonal complex CC59. We were able to confirm the spread of several successful t172-MRSA subclones in regional healthcare and the community. WGS complemented routine surveillance by revealing undetected links between t172-MRSA cases. Targeted, WGS-based typing could enhance MRSA surveillance without the need for routine WGS diagnostics.