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1.
J Forensic Leg Med ; 58: 145-151, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29981506

RESUMEN

OBJECTIVES: To i) describe the demographic and assault characteristics of males alleging recent sexual assault, ii) determine the severity and frequency of general body injury and the frequency of anal and genital injury, iii) identify vulnerability factors and assault characteristics associated with injury. DESIGN: Cross-sectional study. SETTING: Sexual Assault Resource Centre (SARC), Western Australia. PARTICIPANTS: Total of 103 post-pubertal males attending SARC from Jan-2009 to Dec-2016. METHODS: Men underwent a standardised medical examination and data collection by forensically trained doctors following consent for general body and/or ano-genital examination. Men were considered vulnerable if at least one of the following factors was present: current mental illness; intellectual or physical disability; alcohol intoxication; previous sexual victimization; living in prison or homeless (no fixed address), aged < 18 years. Statistical analysis was performed by Fisher exact test. An algorithm was used to classify general body injuries as mild, moderate or severe. RESULTS: At least one vulnerability factor was present in 88.3% of the 103 men. More than one factor was present in 54.4%. General body injury was observed in 58.0% (40/69) of men consenting to general body examination; 46.4%, 10.1% and 1.4% were classified as having respectively, mild, moderate and severe injuries. Three assault characteristics were associated with general body injury: the use of blunt force (p = 0.002), multiple assailants (p = 0.049) and deprivation of liberty (p = 0.040). Genital injury and anal injury was observed in, respectively, 6.5% (5/77) and 14.3% (11/77) of men consenting to ano-genital examination. Of the 49 men examined following completed penetrative anal assault, 18.4% (9/49) had anal injuries. In these 49 men, those assaulted by strangers were more likely to have an anal injury compared to non-stranger assaults (p = 0.019). No demographic, clinical or vulnerability characteristics of the sexually assaulted men were associated with general body, genital and/or anal injury. CONCLUSION: Although general body injuries were more frequent than genital and anal injuries, most of the body injuries were mild in severity. While the majority of men in our study presented with one or more vulnerabilities only assault characteristics (not vulnerabilities) were associated with injury.


Asunto(s)
Víctimas de Crimen/estadística & datos numéricos , Delitos Sexuales , Poblaciones Vulnerables , Adolescente , Adulto , Intoxicación Alcohólica/epidemiología , Canal Anal/lesiones , Australia/epidemiología , Estudios Transversales , Personas con Discapacidad/estadística & datos numéricos , Medicina Legal , Genitales Masculinos/lesiones , Personas con Mala Vivienda/estadística & datos numéricos , Humanos , Puntaje de Gravedad del Traumatismo , Masculino , Trastornos Mentales/epidemiología , Persona de Mediana Edad , Boca/lesiones , Examen Físico , Prisioneros/estadística & datos numéricos , Adulto Joven
2.
Health Inf Manag ; 47(1): 46-55, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28537201

RESUMEN

BACKGROUND: The Sexual Assault Resource Center (SARC) in Perth, Western Australia provides free 24-hour medical, forensic, and counseling services to persons aged over 13 years following sexual assault. OBJECTIVE: The aim of this research was to design a data management system that maintains accurate quality information on all sexual assault cases referred to SARC, facilitating audit and peer-reviewed research. METHODS: The work to develop SARC Medical Services Clinical Information System (SARC-MSCIS) took place during 2007-2009 as a collaboration between SARC and Curtin University, Perth, Western Australia. Patient demographics, assault details, including injury documentation, and counseling sessions were identified as core data sections. A user authentication system was set up for data security. Data quality checks were incorporated to ensure high-quality data. RESULTS: An SARC-MSCIS was developed containing three core data sections having 427 data elements to capture patient's data. Development of the SARC-MSCIS has resulted in comprehensive capacity to support sexual assault research. Four additional projects are underway to explore both the public health and criminal justice considerations in responding to sexual violence. The data showed that 1,933 sexual assault episodes had occurred among 1881 patients between January 1, 2009 and December 31, 2015. Sexual assault patients knew the assailant as a friend, carer, acquaintance, relative, partner, or ex-partner in 70% of cases, with 16% assailants being a stranger to the patient. CONCLUSION: This project has resulted in the development of a high-quality data management system to maintain information for medical and forensic services offered by SARC. This system has also proven to be a reliable resource enabling research in the area of sexual violence.


Asunto(s)
Documentación/métodos , Medicina Legal , Sistemas de Información en Hospital/organización & administración , Investigadores , Delitos Sexuales , Adolescente , Adulto , Exactitud de los Datos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Desarrollo de Programa , Australia Occidental , Adulto Joven
3.
Forensic Sci Int ; 279: 112-120, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28863402

RESUMEN

OBJECTIVES: To describe the frequency and severity of general body injury in women alleging recent sexual assault and then identify demographic and assault characteristics associated with injury severity. DESIGN: Cross-sectional study. SETTING: Sexual Assault Resource Centre (SARC), Western Australia. PARTICIPANTS: Total of 1163 women attending SARC from Jan-2009 to Mar-2015. METHODS: Women underwent a standardised medical examination and data collection by forensically trained doctors. Multivariate ordinal logistic regression analyses were performed. An algorithm was used to classify general body injuries as mild, moderate or severe. RESULTS: General body injury was observed in 71% of women; 52%, 17% and 2% were classified as having respectively, mild, moderate and severe injuries. Moderate or severe injury was observed in 30.4% of women assaulted by intimate partners, 16.4% of women assaulted by strangers and 14.9% of women assaulted by friends/acquaintances. In regression analysis, an interaction between mental illness and assailant type existed after adjusting for age, intellectual disability, time-to-examination, number of assailants and location. Mental illness was an independent predictor for lower injury severity (adjusted odds ratio=0.5, 95% CI 0.3, 0.9) in women assaulted by strangers and higher injury severity in women assaulted by a friend/acquaintance (adjusted odds ratio=2.4, 95% CI 1.6, 3.6). While women assaulted by intimate partners had more frequent moderate-to-severe injuries than other women their current mental illness status was not associated with risk of injury severity. CONCLUSION: This study highlights the increased injury severity in women assaulted by intimate partners. The risk of moderate/severe injury for women with mental illness assaulted by their acquaintances was unexpected and requires further investigation.


Asunto(s)
Delitos Sexuales/estadística & datos numéricos , Heridas y Lesiones/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Australia/epidemiología , Estudios Transversales , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Violencia de Pareja/estadística & datos numéricos , Trastornos Mentales/epidemiología , Persona de Mediana Edad , Análisis Multivariante , Abuso Físico/estadística & datos numéricos , Examen Físico , Adulto Joven
4.
Forensic Sci Int ; 275: 195-202, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28407560

RESUMEN

OBJECTIVES: To describe the frequency of genital and anal injury and associated demographic and assault characteristics in women alleging sexual assault. DESIGN: Cross-sectional study. SETTING: Sexual Assault Resource Centre (SARC), Western Australia. PARTICIPANTS: Total of 1266 women attending SARC from Jan-2009 to Mar-2015. METHODS: Women underwent a standardised data collection procedure by forensically trained doctors. Multivariate logistic regression analyses were performed. MAIN OUTCOME MEASURES: (1) Frequency of genital and anal injuries by type of sexual assault. (2) Identification of independent factors associated with genital and anal injuries following, respectively, completed vaginal and anal penetration. RESULTS: Genital injury was observed in 24.5% of all women with reported completed vaginal penetration; in a subset with no prior sexual intercourse 52.1% had genital injury. Genital injury was more likely with no prior sexual intercourse (adjusted odds ratio [adj. OR] 4.4, 95% confidence interval [95%CI] 2.4-8.0), multiple types of penetrants (adj. OR 1.5, 95%CI 1.0-2.1), if general body injury present and less likely with sedative use and delayed examination. Anal injury, observed in 27.0% of reported completed anal penetrations, was more likely with multiple types of penetrants (adjusted OR 5.0, 95%CI 1.2-21.0), if general body injury present and less likely with delayed examination. CONCLUSION: This study separately quantifies the frequency of both genital and anal injuries in sexually assaulted women. Genital injuries were absent in a large proportion of women regardless of prior vaginal intercourse status. It is anticipated that findings will better inform the community, police and medico-legal evidence to the criminal justice system.


Asunto(s)
Canal Anal/lesiones , Violación , Vagina/lesiones , Vulva/lesiones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Australia/epidemiología , Víctimas de Crimen/estadística & datos numéricos , Estudios Transversales , Femenino , Humanos , Persona de Mediana Edad , Análisis Multivariante , Examen Físico , Adulto Joven
5.
J Forensic Leg Med ; 43: 1-7, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27376175

RESUMEN

OBJECTIVE: To describe the prevalence, risk factors, signs and symptoms of non-fatal strangulation (NFS) in women referred to a Sexual Assault Resource Centre (SARC) following recent sexual assault. METHODS: A cross-sectional study using data routinely collected at time of forensic examination of women (age ≥ 13 years) referred to the Western Australian SARC between Jan-2009 and Mar-2015 alleging a recent sexual assault. Data on demographics, assault characteristics and forensic findings were available. RESULTS: A total of 1064 women were included in the study; 79 (7.4%) alleged NFS during the sexual assault. The prevalence of NFS varied significantly by age-group and assailant type. Of women aged 30-39 years 15.1% gave a history of NFS compared to less than 8.2% in all other age groups. Of women assaulted by an intimate partner, 22.5% gave a history of NFS compared to less than 6% of women assaulted by other assailant types. Of all sexual assaults with NFS, intimate partners were the assailant in 58.2% of cases, whereas in sexual assault cases without NFS, intimate partners were the assailant in 15.9% of cases. Odds of NFS were 8.4 times higher in women sexually assaulted by an intimate partner compared to women assaulted by an acquaintance/friend and 4.9 times higher compared to women assaulted by a stranger. When considering both age and assailant type the highest proportion of NFS (33.9%) was in women aged 30-39 years sexually assaulted by an intimate partner. Other factors associated with NFS during sexual assault included deprivation of liberty, verbal threats, being assaulted in the woman's home and use of additional blunt force. External physical signs of NFS were absent in 49.4% of all NFS sexual assault cases. CONCLUSIONS: This study identifies and quantifies NFS risk factors in female sexual assault and highlights the strong association with intimate partner sexual assault. Greater awareness of NFS in sexual assault should lead to improvement in medical screening, forensic management and safety risk assessment by sexual assault and domestic violence services, emergency departments and police.


Asunto(s)
Asfixia/etiología , Violencia de Pareja/estadística & datos numéricos , Traumatismos del Cuello/etiología , Delitos Sexuales/estadística & datos numéricos , Adulto , Estudios Transversales , Trastornos de Deglución/etiología , Femenino , Humanos , Dolor de Cuello/etiología , Prevalencia , Factores de Riesgo , Adulto Joven
6.
Forensic Sci Med Pathol ; 10(3): 336-43, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24752424

RESUMEN

PURPOSE: To determine the detection frequency of spermatozoa in early evidence kit specimens and in subsequent full forensic specimens in alleged sexual assault. METHODS: Observational cohort study of 100 consecutive alleged sexual assault cases, presenting in Western Australia between 19th July 2008 and 6th February 2012, with both early evidence kit and full forensic evidence specimen collections. Eighty-eight cases were included in the study. Smears from all forensic specimens were analyzed by light microscopy to determine the detection frequency and structural characteristics of spermatozoa. Patient demographic features, characteristics of the alleged assault and details and timing of forensic collections were also recorded. RESULTS: Spermatozoa were detected in early evidence kit specimens in 35 % (31/88) and in full forensic specimens in 42 % (37/88) of all cases (irrespective of type of alleged penetration). In alleged penile-vaginal penetration, spermatozoa were detected in early evidence kit specimens in 40 % (21/53) of cases when both first void urine and vulval gauze wipe were collected. Spermatozoa were detected in full forensic specimens in 45 % (31/69) of cases. Spermatozoa were detected in early evidence kit oral rinse specimens in 6 % (1/18) of cases of alleged penile-oral penetration and in early evidence perianal gauze wipe specimens in 33 % (2/6) cases of alleged penile-anal penetration. Spermatozoa were detected in the early evidence kit first void urine specimen in a single case, 11 % (1/9), in which the nature of the alleged assault was unknown. Spermatozoa were detected in early evidence kit specimens and not in full forensic specimens in 3 % (3/88) of cases. CONCLUSIONS: Early evidence kit specimens are effective in recovery of spermatozoa, and in particular urine and vulval gauze wipe are worthwhile early forensic specimens for the detection of spermatozoa. Collection of early evidence specimens led to detection of spermatozoa-positive cases, which were not detected by subsequent full forensic specimen collection.


Asunto(s)
Abuso Sexual Infantil/diagnóstico , Medicina Legal/métodos , Aplicación de la Ley , Violación/diagnóstico , Espermatozoides , Urinálisis , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Manejo de Especímenes , Coloración y Etiquetado , Factores de Tiempo , Orina/citología , Vulva/citología , Australia Occidental , Adulto Joven
7.
J Fam Plann Reprod Health Care ; 39(3): 186-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23243152

RESUMEN

OBJECTIVE: To follow a series of 100 women attending for fitting of the levonorgestrel-releasing intrauterine system (LNG IUS) registered at a single urban general practice serving the students of the local universities and higher education colleges. METHODS: This was a prospective observational study. A questionnaire was completed by the fitter in discussion with the patient at the time of attendance for IUS fitting. Follow up was by telephone at 6 weeks, 6 months and 9-12 months after fitting. RESULTS: The age range of women within the series was 18-38 years. 97 women were nulliparous. 37 women selected the IUS as their preferred method of contraception. 12 women chose the IUS primarily for non-contraceptive reasons. 75 women still had the IUS at 12 months' follow up with 11 lost to follow up at this point. No pregnancies or perforations were reported. CONCLUSIONS: The IUS is an acceptable form of contraception in young women, including nulliparous women, and should be offered alongside other methods as first line without restriction when offering contraceptive options to this age group.


Asunto(s)
Anticonceptivos Femeninos , Dispositivos Intrauterinos Medicados/estadística & datos numéricos , Levonorgestrel , Estudiantes/estadística & datos numéricos , Adolescente , Adulto , Femenino , Medicina General/estadística & datos numéricos , Humanos , Estudios Prospectivos , Reino Unido , Universidades , Adulto Joven
8.
Tuberculosis (Edinb) ; 91(2): 111-6, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21216669

RESUMEN

We are interested in the role of proteases in the biology of the global human pathogen, Mycobacterium tuberculosis. We have focused on a putative matrix metalloprotease, Rv0198c. In order to investigate its role we constructed an unmarked chromosomal deletion of the gene and analysed the phenotype of the resulting mutant. No differences in growth in axenic culture were seen and there was no measurable change in overall protease activity in cell-free extracts. Transcriptome analysis revealed a small number of changes in gene expression in aerobic growth, with Rv2488c and Rv1971 being over 40-fold up-regulated and qor (Rv1454c) being 20-fold down-regulated; in addition, changes were seen in members of the heat shock regulon. Virulence assays demonstrated that the mutant was able to replicate in human macrophage-like cells (THP-1 cell line) to a comparable degree with the wild-type. However, the mutant was hyper-virulent in the SCID and C57BL/6 mouse models. Our data suggest that Rv0198c plays a role during infection.


Asunto(s)
Proteínas Bacterianas/fisiología , Metaloproteinasas de la Matriz/fisiología , Mycobacterium tuberculosis/enzimología , Animales , Proteínas Bacterianas/genética , Deleción Cromosómica , Femenino , Regulación Bacteriana de la Expresión Génica , Pulmón/microbiología , Macrófagos/microbiología , Metaloproteinasas de la Matriz/genética , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Mycobacterium tuberculosis/crecimiento & desarrollo , Mycobacterium tuberculosis/patogenicidad , Análisis de Secuencia por Matrices de Oligonucleótidos , Fenotipo , Bazo/microbiología , Transcriptoma , Tuberculosis/microbiología , Virulencia/genética
9.
Tuberculosis (Edinb) ; 86(6): 430-7, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16376615

RESUMEN

Mycobacterium tuberculosis genes Rv2557 and Rv2558 have no known function. However, proteome, transcriptome and in situ hybridization studies have shown that these genes are significantly upregulated under carbon-starved conditions and in human granulomas, suggesting that they may play a role in persistence. Single and double deletion mutants of M. tuberculosis H37Rv in Rv2557 and/or Rv2558 were generated to explore their individual and/or collective role(s) in growth and survival. The mutants were assessed for growth and survival in vitro under normal and nutrient-deprived conditions and for virulence in the SCID mouse model. Although highly induced by carbon starvation, loss of Rv2557 and/or Rv2558 affected neither the long-term survival of M. tuberculosis under carbon-starved conditions in vitro, nor its virulence in SCID mice.


Asunto(s)
Carbono/deficiencia , Genes Bacterianos/fisiología , Mycobacterium tuberculosis/genética , Animales , Eliminación de Gen , Genotipo , Ratones , Ratones SCID , Mycobacterium tuberculosis/crecimiento & desarrollo , Mycobacterium tuberculosis/patogenicidad , Virulencia/genética
10.
Mol Microbiol ; 52(6): 1691-702, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15186418

RESUMEN

The function of the Mycobacterium tuberculosis eukaryotic-like protein serine/threonine kinase PknG was investigated by gene knock-out and by expression and biochemical analysis. The pknG gene (Rv0410c), when cloned and expressed in Escherichia coli, encodes a functional kinase. An in vitro kinase assay of the recombinant protein demonstrated that PknG can autophosphorylate its kinase domain as well as its 30 kDa C-terminal portion, which contains a tetratricopeptide (TPR) structural signalling motif. Western analysis revealed that PknG is located in the cytosol as well as in mycobacterial membrane. The pknG gene was inactivated by allelic exchange in M. tuberculosis. The resulting mutant strain causes delayed mortality in SCID mice and displays decreased viability both in vitro and upon infection of BALB/c mice. The reduced growth of the mutant was more pronounced in the stationary phase of the mycobacterial growth cycle and when grown in nutrient-depleted media. The PknG-deficient mutant accumulates glutamate and glutamine. The cellular levels of these two amino acids reached approximately threefold of their parental strain levels. Higher cellular levels of the amine sugar-containing molecules, GlcN-Ins and mycothiol, which are derived from glutamate, were detected in the DeltapknG mutant. De novo glutamine synthesis was shown to be reduced by 50%. This is consistent with current knowledge suggesting that glutamine synthesis is regulated by glutamate and glutamine levels. These data support our hypothesis that PknG mediates the transfer of signals sensing nutritional stress in M. tuberculosis and translates them into metabolic adaptation.


Asunto(s)
Regulación Bacteriana de la Expresión Génica , Ácido Glutámico/metabolismo , Glutamina/metabolismo , Mycobacterium tuberculosis/crecimiento & desarrollo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Western Blotting , Membrana Celular/química , Clonación Molecular , Citoplasma/química , Escherichia coli/genética , Escherichia coli/metabolismo , Eliminación de Gen , Genes Bacterianos , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Mutagénesis Insercional , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/patogenicidad , Proteínas Serina-Treonina Quinasas/genética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/aislamiento & purificación , Tuberculosis/mortalidad , Virulencia/genética
11.
Mol Microbiol ; 51(4): 1003-14, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14763976

RESUMEN

Inositol is utilized by Mycobacterium tuberculosis in the production of its major thiol and of essential cell wall lipoglycans. We have constructed a mutant lacking the gene encoding inositol-1-phosphate synthase (ino1), which catalyses the first committed step in inositol synthesis. This mutant is only viable in the presence of extremely high levels of inositol. Mutant bacteria cultured in inositol-free medium for four weeks showed a reduction in levels of mycothiol, but phosphatidylinositol mannoside, lipomannan and lipoarabinomannan levels were not altered. The ino1 mutant was attenuated in resting macrophages and in SCID mice. We used site-directed mutagenesis to alter four putative active site residues; all four alterations resulted in a loss of activity, and we demonstrated that a D310N mutation caused loss of the active site Zn2+ ion and a conformational change in the NAD+ cofactor.


Asunto(s)
Genes Esenciales , Mycobacterium tuberculosis/genética , Mio-Inositol-1-Fosfato Sintasa/genética , Mio-Inositol-1-Fosfato Sintasa/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión/genética , Cisteína , Análisis Mutacional de ADN , Disacáridos/análisis , Eliminación de Gen , Genes Bacterianos , Glicopéptidos , Inositol/biosíntesis , Lipopolisacáridos/análisis , Macrófagos/microbiología , Ratones , Ratones SCID , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Mutación , Mycobacterium tuberculosis/enzimología , Mycobacterium tuberculosis/crecimiento & desarrollo , Mycobacterium tuberculosis/patogenicidad , Mio-Inositol-1-Fosfato Sintasa/química , Fosfatidilinositoles/análisis , Pirazoles/análisis , Compuestos de Sulfhidrilo/análisis , Tuberculosis/microbiología , Virulencia/genética
12.
Microbiology (Reading) ; 149(Pt 6): 1423-1435, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12777483

RESUMEN

Two-component regulatory systems have been widely implicated in bacterial virulence. To investigate the role of one such system in Mycobacterium tuberculosis, a strain was constructed in which the senX3-regX3 system was deleted by homologous recombination. The mutant strain (Tame15) showed a growth defect after infection of macrophages and was attenuated in both immunodeficient and immunocompetent mice. Competitive hybridization of total RNA from the wild-type and mutant strains to a whole-genome microarray was used to identify changes in gene expression resulting from the deletion. One operon was highly up-regulated in the mutant, indicating that regX3 probably has a role as a repressor of this operon. Other genes which were up- or down-regulated were also identified. Many of the genes showing down-regulation are involved in normal growth of the bacterium, indicating that the mutant strain is subject to some type of growth slow-down or stress. Genes showing differential expression were further grouped according to their pattern of gene expression under other stress conditions. From this analysis 50 genes were identified which are the most likely to be controlled by RegX3. Most of these genes are of unknown function and no obvious motifs were found upstream of the genes identified. Thus, it has been demonstrated that the senX3-regX3 two-component system is involved in the virulence of M. tuberculosis and a number of genes controlled by this system have been identified.


Asunto(s)
Proteínas Bacterianas/genética , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidad , Fosfotransferasas/genética , Animales , Línea Celular , Eliminación de Gen , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Genes Reguladores , Humanos , Macrófagos/microbiología , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Mycobacterium tuberculosis/crecimiento & desarrollo , Regiones Promotoras Genéticas , Regulón , Tuberculosis/microbiología , Virulencia/genética
13.
Infect Immun ; 71(3): 1134-40, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12595424

RESUMEN

Two-component regulatory signal transduction systems are widely distributed among bacteria and enable the organisms to make coordinated changes in gene expression in response to a variety of environmental stimuli. The genome sequence of Mycobacterium tuberculosis contains 11 complete two-component systems, four isolated homologous regulators, and three isolated homologous sensors. We have constructed defined mutations in six of these genes and measured virulence in a SCID mouse model. Mice infected with four of the mutants (deletions of devR, tcrXY, trcS, and kdpDE) died more rapidly than those infected with wild-type bacteria. The other two mutants (narL and Rv3220c) showed no change compared to the wild-type H37Rv strain. The most hypervirulent mutant (devRdelta) also grew more rapidly in the acute stage of infection in immunocompetent mice and in gamma interferon-activated macrophages. These results define a novel class of genes in this pathogen whose presence slows down its multiplication in vivo or increases its susceptibility to host killing mechanisms. Thus, M. tuberculosis actively maintains a balance between its own survival and that of the host.


Asunto(s)
Mycobacterium tuberculosis/patogenicidad , Transducción de Señal , Animales , Eliminación de Gen , Macrófagos/microbiología , Ratones , Ratones Endogámicos DBA , Ratones SCID , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Virulencia
14.
Microbiology (Reading) ; 148(Pt 10): 2975-2986, 2002 10.
Artículo en Inglés | MEDLINE | ID: mdl-12368431

RESUMEN

A library of Mycobacterium tuberculosis insertional mutants was generated with the transposon Tn5370. The junction sequence between the transposon and the mycobacterial chromosome was determined, revealing the positions of 1329 unique insertions, 1189 of which were located in 351 different ORFs. Transposition was not completely random and examination of the most susceptible genome regions revealed a lower-than-average G+C content ranging from 54 to 62 mol%. Mutants were obtained in all of the recognized M. tuberculosis functional protein-coding gene classes. About 30% of the disrupted ORFs had matches elsewhere in the genome that suggested redundancy of function. The effect of gene disruption on the virulence of a selected set of defined mutants was investigated in a severe combined immune deficiency (SCID) mouse model. A range of phenotypes was observed in these mutants, the most notable being the severe attenuation in virulence of a strain disrupted in the Rv1290c gene, which encodes a protein of unknown function. The library described in this study provides a resource of defined mutant strains for use in functional analyses aimed at investigating the role of particular M. tuberculosis genes in virulence and defining their potential as targets for new anti-mycobacterial drugs or as candidates for deletion in a rationally attenuated live vaccine.


Asunto(s)
Elementos Transponibles de ADN/genética , Biblioteca de Genes , Mutagénesis Insercional , Mycobacterium tuberculosis/patogenicidad , Tuberculosis Pulmonar/microbiología , Animales , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones SCID , Mutación , Mycobacterium tuberculosis/genética , Sistemas de Lectura Abierta/genética , Virulencia
15.
Infect Immun ; 70(6): 3080-4, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12011001

RESUMEN

A mutant of Mycobacterium tuberculosis defective in the metabolism of L-arginine was constructed by allelic exchange mutagenesis. The argF mutant strain required exogenous L-arginine for growth in vitro, and in the presence of 0.96 mM L-arginine, it achieved a growth rate and cell density in stationary phase comparable to those of the wild type. The mutant strain was also able to grow in the presence of high concentrations of argininosuccinate, but its auxotrophic phenotype could not be rescued by L-citrulline, suggesting that the DeltaargF::hyg mutation exerted a polar effect on the downstream argG gene but not on argH. The mutant strain displayed reduced virulence in immunodeficient SCID mice and was highly attenuated in immunocompetent DBA/2 mice, suggesting that L-arginine availability is restricted in vivo.


Asunto(s)
Arginina/fisiología , Mycobacterium tuberculosis/crecimiento & desarrollo , Animales , Arginina/biosíntesis , Modelos Animales de Enfermedad , Inmunocompetencia , Cinética , Ratones , Ratones Endogámicos DBA , Ratones SCID , Mutagénesis , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidad , Ornitina Carbamoiltransferasa/genética , Fenotipo , Especificidad por Sustrato , Tuberculosis Pulmonar/microbiología , Virulencia
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