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1.
BMC Psychiatry ; 24(1): 260, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38589822

RESUMO

INTRODUCTION: Drug courts are criminal justice programs to divert people with substance use disorders from incarceration into treatment. Drug courts have become increasingly popular in the US and other countries. However, their effectiveness in reducing important public health outcomes such as recidivism and substance-related health harms remains ambiguous and contested. We used nationwide register data from Sweden to evaluate the effectiveness of contract treatment sanction, the Swedish version of drug court, in reducing substance misuse, adverse somatic and mental health outcomes, and recidivism. METHODS: In this prospective cohort study, two quasi-experimental designs were used: difference-in-differences and the within-individual design. In the latter, we compared the risk of outcomes during time on contract treatment to, 1) parole after imprisonment and, 2) probation. RESULTS: The cohort included 11,893 individuals (13% women) who underwent contract treatment. Contract treatment was associated with a reduction of 7 percentage points (95% CI: -.088, -.055) in substance misuse, 5 percentage points (-.064, -.034) in adverse mental health events, 9 percentage points (-.113, -.076) in adverse somatic health events, and 3 fewer charges (-3.16, -2.85) for crime in difference-in-differences analyses. Within-individual associations suggested that the same individual had longer times-to-event for all outcomes during contract treatment than on parole or on probation. CONCLUSIONS: Contract treatment is an effective intervention from both public health and criminal justice perspective. Our findings suggest that it is a superior alternative to incarceration in its target group. Further, we find that an implementation approach that is less punitive and more inclusive than what is typical in the US can be successful.


Assuntos
Reincidência , Transtornos Relacionados ao Uso de Substâncias , Humanos , Feminino , Masculino , Encarceramento , Estudos Prospectivos , Crime/psicologia , Transtornos Relacionados ao Uso de Substâncias/terapia
2.
Int J Med Microbiol ; 313(4): 151583, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37331050

RESUMO

Francisella tularensis is the causative agent of tularemia, a zoonotic disease with a wide host range. F. tularensis ssp. holarctica (Fth) is of clinical relevance for European countries, including Germany. Whole genome sequencing methods, including canonical Single Nucleotide Polymorphism (canSNP) typing and whole genome SNP typing, have revealed that European Fth strains belong to a few monophyletic populations. The majority of German Fth isolates belong to two basal phylogenetic clades B.6 (biovar I) and B.12 (biovar II). Strains of B.6 and B.12 seem to differ in their pathogenicity, and it has been shown that strains of biovar II are resistant against erythromycin. In this study, we present data corroborating our previous data demonstrating that basal clade B.12 can be divided into clades B.71 and B.72. By applying phylogenetic whole genome analysis as well as proteome analysis, we could verify that strains of these two clades are distinct from one another. This was confirmed by measuring the intensity of backscatter light on bacteria grown in liquid media. Strains belonging to clades B.6, B.71 or B.72 showed clade-specific backscatter growth curves. Furthermore, we present the whole genome sequence of strain A-1341, as a reference genome of clade B.71, and whole proteomes comparison of Fth strains belonging to clades B.6, B.71 and B.72. Further research is necessary to investigate phenotypes and putative differences in pathogenicity of the investigated different clades of Fth to better understand the relationship between observed phenotypes, pathogenicity and distribution of Fth strains.


Assuntos
Francisella tularensis , Tularemia , Animais , Francisella tularensis/genética , Filogenia , Tularemia/microbiologia , Zoonoses/microbiologia , Fenótipo
3.
Bioinformatics ; 37(21): 3932-3933, 2021 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-34469515

RESUMO

SUMMARY: The Flexible Taxonomy Database framework provides a method for modification and merging official and custom taxonomic databases to create improved databases. Using such databases will increase accuracy and precision of existing methods to classify sequence reads. AVAILABILITY AND IMPLEMENTATION: Source code is freely available at https://github.com/FOI-Bioinformatics/flextaxd and installable through Bioconda.


Assuntos
Software , Bases de Dados Factuais
4.
Appl Environ Microbiol ; 87(6)2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33397692

RESUMO

Francisella tularensis, the causative agent of the zoonotic disease tularemia, can cause seasonal outbreaks of acute febrile illness in humans with disease peaks in late summer to autumn. Interestingly, its mechanisms for environmental persistence between outbreaks are poorly understood. One hypothesis is that F. tularensis forms biofilms in aquatic environments. We utilized two fully virulent wild-type strains: FSC200 (Francisella tularensis subsp. holarctica) and Schu S4 (Francisella tularensis subsp. tularensis) and three control strains, the attenuated live vaccine strain (LVS; F. tularensis subsp. holarctica), a Schu S4 ΔwbtI mutant that is documented to form biofilms, and the low-virulence strain U112 of the closely related species Francisella novicida Strains were incubated in saline solution (0.9% NaCl) microcosms for 24 weeks at both 4°C and 20°C, whereupon viability and biofilm formation were measured. These temperatures were selected to approximate winter and summer temperatures of fresh water in Scandinavia, respectively. U112 and Schu S4 ΔwbtI formed biofilms, but F. tularensis strains FSC200 and Schu S4 and the LVS did not. All strains exhibited prolonged viability at 4°C compared to 20°C. U112 and FSC200 displayed remarkable long-term persistence at 4°C, with only 1- and 2-fold log reductions, respectively, of viable cells after 24 weeks. Schu S4 exhibited lower survival, yielding no viable cells by week 20. At 24 weeks, cells from FSC200, but not from Schu S4, were still fully virulent in mice. Taken together, these results demonstrate biofilm-independent, long-term survival of pathogenic F. tularensis subsp. holarctica in conditions that mimic overwinter survival in aquatic environments.IMPORTANCE Tularemia, a disease caused by the environmental bacterium Francisella tularensis, is characterized by acute febrile illness. F. tularensis is highly infectious: as few as 10 organisms can cause human disease. Tularemia is not known to be spread from person to person. Rather, all human infections are independently acquired from the environment via the bite of blood-feeding arthropods, ingestion of infected food or water, or inhalation of aerosolized bacteria. Despite the environmental origins of human disease events, the ecological factors governing the long-term persistence of F. tularensis in nature between seasonal human outbreaks are poorly understood. The significance of our research is in identifying conditions that promote long-term survival of fully virulent F. tularensis outside a mammalian host or insect vector. These conditions are similar to those found in natural aquatic environments in winter and provide important new insights on how F. tularensis may persist long-term in the environment.


Assuntos
Francisella tularensis , Água Doce/microbiologia , Animais , Feminino , Francisella tularensis/patogenicidade , Francisella tularensis/fisiologia , Camundongos Endogâmicos C57BL , Temperatura , Tularemia , Virulência
5.
Crim Behav Ment Health ; 28(6): 476-491, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30328151

RESUMO

BACKGROUND: Aggression replacement training (ART) is a widely used cognitive behavioural intervention for reducing aggression-related recidivism among criminal offenders. Its effectiveness in reducing offending, however, remains uncertain. AIM: To examine the effect of ART on adult offenders' criminal recidivism rates. METHOD: We compared 1,124 convicted adult offenders who began ART in the Swedish Prison and Probation Services 2003-2009 with 3,372 offenders in the system at the same time who did not participate in ART. Linkage with nationwide, longitudinal registries allowed extensive propensity score-matched controlling for baseline differences (e.g. sociodemographics, criminal history, psychiatric morbidity, and substance misuse) between groups. RESULTS: Intent-to-treat analyses suggested similar 1-year general reconviction rates (according to the National Crime Register) between the two groups (ART participants 50% [n = 465]: comparison participants 51% [n = 1,492]; hazard ratio [HR] = 0.97, 95% CI [0.88, 1.07]) and similar one-year violent recidivism (ART participants 19% [n = 174]: comparison participants 18% [n = 547]; HR = 1.02, 95% CI [0.89, 1.17]). For ART completers, findings suggested a marginal decrease in reconvictions for any recidivism, but not for violent recidivism specifically. Sensitivity analyses yielded similar results. CONCLUSIONS AND IMPLICATIONS: Our findings add to the emerging literature suggesting no effect of ART on reoffending among adult offenders. Originally designed for adolescents, it may be that the programme should include components for more adult-specific needs. Further, although group differences in reoffending did not emerge, research with a wider range of outcomes may be worthwhile before abandoning this approach with offenders.


Assuntos
Agressão , Terapia Cognitivo-Comportamental/métodos , Crime/psicologia , Criminosos/psicologia , Prisioneiros/psicologia , Reincidência/prevenção & controle , Adolescente , Adulto , Feminino , Humanos , Masculino , Prisioneiros/estatística & dados numéricos , Pontuação de Propensão , Modelos de Riscos Proporcionais , Reincidência/estatística & dados numéricos , Suécia
6.
J Antimicrob Chemother ; 72(9): 2539-2543, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28605439

RESUMO

Background: Tularaemia is a zoonotic disease caused by the bacterium Francisella tularensis. In Germany, the disease is still rare (e.g. 34 human cases reported in 2015). There is a lack of data about the susceptibility of F. tularensis strains to antibiotics, because many cases are diagnosed using serological assays only. Objectives: The antibiotic susceptibility in vitro of F. tularensis subsp. holarctica strains isolated in Germany was assessed to determine whether the currently recommended empirical therapy is still adequate. Methods: A total of 128 F. tularensis strains were investigated that were collected between 2005 and 2014 in Germany from wild animals, ticks and humans. All isolates were genotyped using real-time PCR assays targeting canonical SNPs, and antibiotic susceptibility was tested using MIC test strips on agar plates. MIC values were interpreted using CLSI breakpoints. Results: The strains were susceptible to antibiotics commonly recommended for tularaemia therapy, i.e. aminoglycosides (MIC90 values: gentamicin 1 mg/L; streptomycin 4.0 mg/L), tetracyclines (MIC90 values: tetracycline 0.5 mg/L; doxycycline 1.5 mg/L) and quinolones (MIC90 value: ciprofloxacin 0.064 mg/L). Chloramphenicol (MIC90 value: 3.0 mg/L) may be of value in treatment of tularaemia meningitis. Ninety-four isolates were susceptible to erythromycin, which defines biovar I (genotypes B.4 and B.6); 34 were resistant (biovar II; genotype B.12). Conclusions: The F. tularensis isolates investigated in this study showed the typical antibiotic susceptibility pattern that was previously observed in other countries. Therefore, recommendations for empirical antibiotic therapy of tularaemia can remain unchanged. However, antibiotic susceptibility testing of clinical isolates should be performed whenever possible.


Assuntos
Antibacterianos/farmacologia , Francisella tularensis/efeitos dos fármacos , Tularemia/microbiologia , Animais , Animais Selvagens , Ciprofloxacina/farmacologia , Doxiciclina/farmacologia , Raposas/microbiologia , Francisella tularensis/classificação , Francisella tularensis/genética , Genótipo , Alemanha/epidemiologia , Humanos , Testes de Sensibilidade Microbiana/métodos , Guaxinins/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Roedores/microbiologia , Tetraciclina/farmacologia , Carrapatos/microbiologia , Tularemia/tratamento farmacológico , Tularemia/epidemiologia
7.
Am J Public Health ; 107(2): 322-328, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27997235

RESUMO

OBJECTIVES: To determine the influences of victimization experience and familial factors on the association between sexual minority status and psychological health outcomes among adolescents. METHODS: We used data from the Child and Adolescent Twin Study in Sweden, a prospective, population-based study of all twins born in Sweden since 1992. Cross-sectional analyses included individuals who completed assessments at age 18 years (n = 4898) from 2000 to 2013. We also compared psychological health among sexual minority adolescents and their nonminority co-twins. RESULTS: Sexual minority adolescents were more likely than were unrelated nonminority adolescents to report victimization experiences, including emotional abuse, physical abuse or neglect, and sexual abuse. Sexual minority adolescents also reported significantly more symptoms of anxiety, depression, attention-deficit/hyperactivity disorder, disordered eating, and substance misuse in addition to increased parent-reported behavior problems. Victimization experience partially mediated these associations. However, when controlling for unmeasured familial confounding factors by comparing sexual minority adolescents to their same-sex, nonminority co-twins, the effect of sexual minority status on psychological health was almost entirely attenuated. CONCLUSIONS: Familial factors-common genetic or environmental influences-may explain decreased psychological adjustment among sexual minority adolescents.


Assuntos
Vítimas de Crime , Família , Psicologia do Adolescente , Minorias Sexuais e de Gênero/psicologia , Adolescente , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores de Risco , Delitos Sexuais/psicologia , Delitos Sexuais/estatística & dados numéricos , Suécia/epidemiologia
8.
J Antimicrob Chemother ; 71(10): 2815-23, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27334667

RESUMO

OBJECTIVES: We analysed diverse strains of Francisella tularensis subsp. holarctica to assess if its division into biovars I and II is associated with specific mutations previously linked to erythromycin resistance and to determine the distribution of this resistance trait across this subspecies. METHODS: Three-hundred and fourteen F. tularensis subsp. holarctica strains were tested for erythromycin susceptibility and whole-genome sequences for these strains were examined for SNPs in genes previously associated with erythromycin resistance. Each strain was assigned to a global phylogenetic framework using genome-wide canonical SNPs. The contribution of a specific SNP to erythromycin resistance was examined using allelic exchange. The geographical distribution of erythromycin-resistant F. tularensis strains was further investigated by literature search. RESULTS: There was a perfect correlation between biovar II strains (erythromycin resistance) and the phylogenetic group B.12. Only B.12 strains had an A → C SNP at position 2059 in the three copies of the rrl gene. Introducing 2059C into an rrl gene of an erythromycin-susceptible F. tularensis strain resulted in resistance. An additional 1144 erythromycin-resistant strains were identified from the scientific literature, all of them from Eurasia. CONCLUSIONS: Erythromycin resistance in F. tularensis is caused by an A2059C rrl gene mutation, which exhibits a strictly clonal inheritance pattern found only in phylogenetic group B.12. This group is an extremely successful clone, representing the most common type of F. tularensis throughout Eurasia.


Assuntos
Antibacterianos/farmacologia , Eritromicina/farmacologia , Francisella tularensis/efeitos dos fármacos , Francisella tularensis/genética , Polimorfismo de Nucleotídeo Único , Farmacorresistência Bacteriana/genética , Genes Bacterianos , Genoma Bacteriano , Mutação , Fenótipo , Filogenia , RNA Ribossômico 23S/genética
9.
Arch Sex Behav ; 45(5): 1163-72, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26754158

RESUMO

Prior research with selected clinical and forensic samples suggests associations between paraphilic sexual interests (e.g., exhibitionism and sexual sadism) and sexually coercive behavior. However, no study to date used a large, representative and genetically informative population sample to address the potential causal nature of this association. We used self-report data on paraphilic and sexually coercive behavior from 5990 18- to 32-year-old male and female twins from a contemporary Finnish population cohort. Logistic regression and co-twin control models were employed to examine if paraphilic behaviors were causally related to coercive behavior or if suggested links were confounded by familial (genetic or common family environment) risk factors. Results indicated that associations between four out of five tested paraphilic behaviors (exhibitionism, masochism, sadism, and voyeurism, respectively) and sexually coercive behavior were moderate to strong. Transvestic fetishism was not independently associated with sexual coercion. Comparisons of twins reporting paraphilic behavior with their paraphilic behavior-discordant twin further suggested that associations were largely independent of shared genetic and environmental confounds, consistent with a causal association. In conclusion, similar to previously reported predictive effects of paraphilias on sexual crime recidivism, paraphilic behavior among young adults in the general population increases sexual offending risk. Further, early identification of paraphilic interest and preventive interventions with at-risk individuals might also reduce perpetration of first-time sexual violence.


Assuntos
Coerção , Transtornos Parafílicos , Comportamento Sexual , Gêmeos , Adolescente , Adulto , Feminino , Humanos , Masculino , Transtornos Parafílicos/epidemiologia , Transtornos Parafílicos/psicologia , Fatores de Risco , Autorrelato , Delitos Sexuais , Comportamento Sexual/psicologia , Comportamento Sexual/estatística & dados numéricos , Gêmeos/psicologia , Gêmeos/estatística & dados numéricos , Adulto Jovem
10.
Emerg Infect Dis ; 21(1): 153-5, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25531286

RESUMO

In November 2012, a group of 7 persons who participated in a hare hunt in North Rhine-Westphalia, Germany, acquired tularemia. Two F. tularensis subsp. holarctica isolates were cultivated from human and hare biopsy material. Both isolates belonged to the FTN002-00 genetic subclade (derived for single nucleotide polymorphisms B.10 and B.18), thus indicating likely hare-to-human transmission.


Assuntos
Francisella tularensis/genética , Lebres/microbiologia , Tularemia/transmissão , Animais , Genes Bacterianos , Alemanha , Humanos , Polimorfismo de Nucleotídeo Único , Tularemia/microbiologia , Zoonoses
11.
Bioinformatics ; 30(12): 1762-4, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24574113

RESUMO

SUMMARY: Advances in typing methodologies have recently reformed the field of molecular epidemiology of pathogens. The falling cost of sequencing technologies is creating a deluge of whole genome sequencing data that burdens bioinformatics resources and tool development. In particular, single nucleotide polymorphisms in core genomes of pathogens are recognized as the most important markers for inferring genetic relationships because they are evolutionarily stable and amenable to high-throughput detection methods. Sequence data will provide an excellent opportunity to extend our understanding of infectious disease when the challenge of extracting knowledge from available sequence resources is met. Here, we present an efficient and user-friendly genotype classification pipeline, CanSNPer, based on an easily expandable database of predefined canonical single nucleotide polymorphisms. AVAILABILITY AND IMPLEMENTATION: All documentation and Python-based source code for the CanSNPer are freely available at http://github.com/adrlar/CanSNPer.


Assuntos
Técnicas de Genotipagem/métodos , Tipagem Molecular/métodos , Software , Genômica/métodos , Genótipo , Polimorfismo de Nucleotídeo Único
12.
Anal Biochem ; 487: 30-7, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26170001

RESUMO

Real-time polymerase chain reaction (qPCR) is the cornerstone of DNA analysis, enabling detection and quantification of minute nucleic acid amounts. However, PCR-based analysis is limited, in part, by the presence of inhibitors in the samples. PCR inhibition has been viewed solely as failure to efficiently generate amplicons, that is, amplification inhibition. Humic substances (HS) are well-known inhibitors of PCR amplification. Here we show that HS from environmental samples, specifically humic acid (HA), are very potent detection inhibitors, that is, quench the fluorescence signal of double-stranded DNA (dsDNA) binding dyes. HA quenched the fluorescence of the commonly used qPCR dyes EvaGreen, ResoLight, SYBR Green I, and SYTO 82, generating lowered amplification plots, although amplicon production was unaffected. For EvaGreen, 500 ng of HA quenched nearly all fluorescence, whereas 1000 ng of HA completely inhibited amplification when applying Immolase DNA polymerase with bovine serum albumin (BSA). Fluorescence spectroscopy measurements showed that HA quenching was either static or collisional and indicated that HA bound directly to the dye. Fulvic acid did not act as a qPCR detection inhibitor but inhibited amplification similarly to HA. Hydrolysis probe fluorescence was not quenched by HA. Detection inhibition is an overlooked phenomenon that needs to be considered to allow for development of optimal qPCR assays.


Assuntos
DNA/antagonistas & inibidores , Fluorescência , Substâncias Húmicas , Reação em Cadeia da Polimerase em Tempo Real , Corantes/química , DNA/química , DNA/genética , Espectrometria de Fluorescência
13.
Arch Sex Behav ; 44(1): 149-56, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24752790

RESUMO

Child maltreatment is associated with adult sexually coercive behavior. The association may be causal or confounders that increase the risk of both childhood victimization and sexually coercive behavior might explain the observed links. We examined if childhood maltreatment was related to sexual coercion independently of familial (genetic or common family environment) risk factors, thereby addressing potential causality. Participants were 6,255 18 to 33-year-old twins from the Finnish population-based study "Genetics of Sex and Aggression" who responded to self-report questionnaires of child maltreatment and sexually coercive behavior. We used generalized estimating equations to elucidate risk of sexual coercion in maltreated compared to unrelated, non-maltreated individuals. To adjust for unmeasured familial factors, we used the co-twin control method and compared sexual coercion risk within maltreatment-discordant twin pairs. Further, we examined possible differential effects of maltreatment subtypes and compared mean differences in maltreatment summary scores between sexually coercive individuals and controls. Sexual coercion was moderately more common among individuals maltreated as children versus unrelated controls (38.3 vs. 22.8 %; age- and gender-adjusted odds ratio, aOR = 2.31, 95 % CI 1.75-3.05) and the risk increase remained similar within maltreatment-discordant twins (OR = 2.82, 95 % CI 1.42-5.61). Moreover, different maltreatment subtypes predicted sexual coercion equally well and effect sizes remained similar within discordant twin pairs. We conclude that associations between child maltreatment and sexual coercion are largely independent of shared familial confounds, consistent with a causal inference. Importantly, detection and targeted interventions for maltreated children should remain a priority to reduce societal sexually coercive behavior.


Assuntos
Maus-Tratos Infantis/estatística & dados numéricos , Coerção , Vítimas de Crime/estatística & dados numéricos , Comportamento Sexual/estatística & dados numéricos , Gêmeos/estatística & dados numéricos , Adolescente , Adulto , Abuso Sexual na Infância/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Inquéritos e Questionários , Adulto Jovem
14.
Clin Infect Dis ; 59(11): 1546-53, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25097081

RESUMO

BACKGROUND: The bacterium Francisella tularensis is recognized for its virulence, infectivity, genetic homogeneity, and potential as a bioterrorism agent. Outbreaks of respiratory tularemia, caused by inhalation of this bacterium, are poorly understood. Such outbreaks are exceedingly rare, and F. tularensis is seldom recovered from clinical specimens. METHODS: A localized outbreak of tularemia in Sweden was investigated. Sixty-seven humans contracted laboratory-verified respiratory tularemia. F. tularensis subspecies holarctica was isolated from the blood or pleural fluid of 10 individuals from July to September 2010. Using whole-genome sequencing and analysis of single-nucleotide polymorphisms (SNPs), outbreak isolates were compared with 110 archived global isolates. RESULTS: There were 757 SNPs among the genomes of the 10 outbreak isolates and the 25 most closely related archival isolates (all from Sweden/Finland). Whole genomes of outbreak isolates were >99.9% similar at the nucleotide level and clustered into 3 distinct genetic clades. Unexpectedly, high-sequence similarity grouped some outbreak and archival isolates that originated from patients from different geographic regions and up to 10 years apart. Outbreak and archival genomes frequently differed by only 1-3 of 1 585 229 examined nucleotides. CONCLUSIONS: The outbreak was caused by diverse clones of F. tularensis that occurred concomitantly, were widespread, and apparently persisted in the environment. Multiple independent acquisitions of F. tularensis from the environment over a short time period suggest that natural outbreaks of respiratory tularemia are triggered by environmental cues. The findings additionally caution against interpreting genome sequence identity for this pathogen as proof of a direct epidemiological link.


Assuntos
Surtos de Doenças , Francisella tularensis/genética , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Tularemia/epidemiologia , Tularemia/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA Bacteriano/genética , Feminino , Francisella tularensis/classificação , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Polimorfismo de Nucleotídeo Único , Suécia/epidemiologia , Adulto Jovem
15.
Emerg Infect Dis ; 20(5): 861-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24755401

RESUMO

We used whole-genome analysis and subsequent characterization of geographically diverse strains using new genetic signatures to identify distinct subgroups within Francisella tularensis subsp. tularensis group A.I: A.I.3, A.I.8, and A.I.12. These subgroups exhibit complex phylogeographic patterns within North America. The widest distribution was observed for A.I.12, which suggests an adaptive advantage.


Assuntos
Francisella tularensis/classificação , Tularemia/epidemiologia , Francisella tularensis/genética , Genoma Viral , Humanos , Filogenia , Filogeografia , Polimorfismo de Nucleotídeo Único , Tularemia/microbiologia , Estados Unidos/epidemiologia
16.
Nat Genet ; 37(2): 153-9, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15640799

RESUMO

Francisella tularensis is one of the most infectious human pathogens known. In the past, both the former Soviet Union and the US had programs to develop weapons containing the bacterium. We report the complete genome sequence of a highly virulent isolate of F. tularensis (1,892,819 bp). The sequence uncovers previously uncharacterized genes encoding type IV pili, a surface polysaccharide and iron-acquisition systems. Several virulence-associated genes were located in a putative pathogenicity island, which was duplicated in the genome. More than 10% of the putative coding sequences contained insertion-deletion or substitution mutations and seemed to be deteriorating. The genome is rich in IS elements, including IS630 Tc-1 mariner family transposons, which are not expected in a prokaryote. We used a computational method for predicting metabolic pathways and found an unexpectedly high proportion of disrupted pathways, explaining the fastidious nutritional requirements of the bacterium. The loss of biosynthetic pathways indicates that F. tularensis is an obligate host-dependent bacterium in its natural life cycle. Our results have implications for our understanding of how highly virulent human pathogens evolve and will expedite strategies to combat them.


Assuntos
Francisella tularensis/genética , Genoma Bacteriano , Sequência de Bases , Elementos de DNA Transponíveis , Francisella tularensis/crescimento & desenvolvimento , Ilhas Genômicas , Ferro/metabolismo , Dados de Sequência Molecular , Mutação , Análise de Sequência de DNA , Virulência/genética
17.
Environ Microbiol ; 15(2): 634-45, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23253075

RESUMO

Previous studies of the causative agent of tularaemia, Francisella tularensis have identified phylogeographic patterns suggestive of environmental maintenance reservoirs. To investigate the phylogeography of tularaemia in Sweden, we selected 163 clinical isolates obtained during 1995-2009 in 10 counties and sequenced one isolate's genome to identify new genetic markers. An improved typing scheme based on two indels and nine SNPs was developed using hydrolysis or TaqMan MGB probe assays. The results showed that much of the known global genetic diversity of F. tularensis subsp. holarctica is present in Sweden. Thirteen of the 163 isolates belonged to a new genetic group that is basal to all other known members of the major genetic clade B.I, which is spread across the Eurosiberian region. One hundred and twenty-five of the 163 Swedish isolates belonged to B.I, but individual clades' frequencies differed from county to county (P < 0.001). Subsequent analyses revealed a correlation between genotype variation over time and recurrent outbreaks at specific places, supporting the 'maintenance reservoir' environmental maintenance hypothesis. Most importantly, the findings reveal the presence of diverse source populations of F. tularensis subsp. holarctica in Sweden and suggest a historical spread of the disease from Scandinavia to other parts of Eurosiberia.


Assuntos
Francisella tularensis/classificação , Francisella tularensis/genética , Tularemia/microbiologia , Técnicas de Tipagem Bacteriana , Sequência de Bases , Variação Genética , Genoma Bacteriano/genética , Genótipo , Humanos , Filogeografia , Países Escandinavos e Nórdicos , Suécia , Fatores de Tempo , Tularemia/patologia
18.
BMC Microbiol ; 13: 61, 2013 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-23517149

RESUMO

BACKGROUND: Tularemia is a zoonotic disease caused by Francisella tularensis that has been found in many different vertebrates. In Germany most human infections are caused by contact with infected European brown hares (Lepus europaeus). The aim of this study was to elucidate the epidemiology of tularemia in hares using phenotypic and genotypic characteristics of F. tularensis. RESULTS: Cultivation of F. tularensis subsp. holarctica bacteria from organ material was successful in 31 of 52 hares that had a positive PCR result targeting the Ft-M19 locus. 17 isolates were sensitive to erythromycin and 14 were resistant. Analysis of VNTR loci (Ft-M3, Ft-M6 and Ft-M24), INDELs (Ftind33, Ftind38, Ftind49, RD23) and SNPs (B.17, B.18, B.19, and B.20) was shown to be useful to investigate the genetic relatedness of Francisella strains in this set of strains. The 14 erythromycin resistant isolates were assigned to clade B.I, and 16 erythromycin sensitive isolates to clade B.IV and one isolate was found to belong to clade B.II. MALDI-TOF mass spectrometry (MS) was useful to discriminate strains to the subspecies level. CONCLUSIONS: F. tularensis seems to be a re-emerging pathogen in Germany. The pathogen can easily be identified using PCR assays. Isolates can also be identified within one hour using MALDI-TOF MS in laboratories where specific PCR assays are not established. Further analysis of strains requires genotyping tools. The results from this study indicate a geographical segregation of the phylogenetic clade B.I and B.IV, where B.I strains localize primarily within eastern Germany and B.IV strains within western Germany. This phylogeographical pattern coincides with the distribution of biovar I (erythromycin sensitive) and biovar II (erythromycin resistance) strains. When time and costs are limiting parameters small numbers of isolates can be analysed using PCR assays combined with DNA sequencing with a focus on genetic loci that are most likely discriminatory among strains found in a specific area. In perspective, whole genome data will have to be investigated especially when terrorist attack strains need to be tracked to their genetic and geographical sources.


Assuntos
Francisella tularensis/classificação , Francisella tularensis/genética , Variação Genética , Lebres/microbiologia , Doenças dos Roedores/microbiologia , Tularemia/veterinária , Estruturas Animais/microbiologia , Animais , Antibacterianos/farmacologia , Análise por Conglomerados , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Farmacorresistência Bacteriana , Eritromicina/farmacologia , Francisella tularensis/isolamento & purificação , Genótipo , Alemanha , Testes de Sensibilidade Microbiana , Repetições Minissatélites , Tipagem Molecular , Filogeografia , Reação em Cadeia da Polimerase , Tularemia/microbiologia
19.
BMC Vet Res ; 9: 252, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24330665

RESUMO

BACKGROUND: Francisellosis, caused by the bacterium Francisella noatunensis subsp. noatunensis, remains a serious threat to Atlantic cod (Gadhus morhua) farming in Norway and potentially in other countries. As outbreak strains appear clonal in population structure, access to highly discriminatory typing tools is critical for understanding the epidemiology of francisellosis infections in aquaculture. In this study, a simplified multiple-locus variable-number of tandem repeat analysis (MLVA) targeting five highly polymorphic variable number of tandem repeat (VNTR) loci in a single multiplex PCR was developed to rapidly discriminate between outbreak strains. RESULTS: The assay resulted in identification of at least 13 different allelic profiles or subpopulations among 91 F. noatunensis isolates from farmed cod in Norway. The VNTR loci appear relatively stable, with isolates originating from individual outbreaks showing identical MLVA profiles following repeated passage. MLVA displayed greater discriminatory power than pulse-field gel electrophoresis (PFGE). Both MLVA and PFGE show good epidemiological concordance by their abilities to separate outbreak strains from epidemiologically unrelated isolates. CONCLUSIONS: The MLVA method presented here is robust, easy to perform and provides a good alternative to other typing systems for F. noatunensis subsp. noatunensis and epidemiological study of francisellosis in cod.


Assuntos
Eletroforese Capilar/veterinária , Doenças dos Peixes/microbiologia , Francisella/genética , Infecções por Bactérias Gram-Negativas/veterinária , Tipagem de Sequências Multilocus/veterinária , Sequências de Repetição em Tandem/genética , Animais , Surtos de Doenças/veterinária , Eletroforese em Gel de Campo Pulsado/veterinária , Doenças dos Peixes/diagnóstico , Gadus morhua/microbiologia , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por Bactérias Gram-Negativas/microbiologia , Repetições Minissatélites/genética , Tipagem de Sequências Multilocus/métodos , Reação em Cadeia da Polimerase Multiplex/veterinária
20.
J Infect Dis ; 205(2): 297-304, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22124130

RESUMO

BACKGROUND: We aimed to evaluate the potential association of mosquito prevalence in a boreal forest area with transmission of the bacterial disease tularemia to humans, and model the annual variation of disease using local weather data. METHODS: A prediction model for mosquito abundance was built using weather and mosquito catch data. Then a negative binomial regression model based on the predicted mosquito abundance and local weather data was built to predict annual numbers of humans contracting tularemia in Dalarna County, Sweden. RESULTS: Three hundred seventy humans were diagnosed with tularemia between 1981 and 2007, 94% of them during 7 summer outbreaks. Disease transmission was concentrated along rivers in the area. The predicted mosquito abundance was correlated (0.41, P < .05) with the annual number of human cases. The predicted mosquito peaks consistently preceded the median onset time of human tularemia (temporal correlation, 0.76; P < .05). Our final predictive model included 5 environmental variables and identified 6 of the 7 outbreaks. CONCLUSIONS: This work suggests that a high prevalence of mosquitoes in late summer is a prerequisite for outbreaks of tularemia in a tularemia-endemic boreal forest area of Sweden and that environmental variables can be used as risk indicators.


Assuntos
Culicidae , Surtos de Doenças , Francisella tularensis , Tularemia/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Vetores de Doenças , Humanos , Incidência , Lactente , Pessoa de Meia-Idade , Estações do Ano , Suécia/epidemiologia , Árvores , Tularemia/transmissão , Tempo (Meteorologia) , Adulto Jovem
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