RESUMO
HIV/HCV prevention among people who inject drugs (PWID) is of key public health importance. We aimed to assess the impact of COVID-19 and associated response measures on HIV/HCV prevention services and socio-economic status of PWID in high-HIV-risk sites. Sites with recent (2011-2019) HIV outbreaks among PWID in Europe North America and Israel, that had been previously identified, were contacted early May 2020. Out of 17 sites invited to participate, 13 accepted. Semi-structured qualitative site reports were prepared covering data from March to May 2020, analyzed/coded and confirmed with a structured questionnaire, in which all sites explicitly responded to all 103 issues reported in the qualitative reports. Opioid maintenance treatment, needle/syringe programs and antiretroviral treatment /hepatitis C treatment continued, but with important reductions and operational changes. Increases in overdoses, widespread difficulties with food and hygiene needs, disruptions in drug supply, and increased homelessness were reported. Service programs rapidly reformed long established, and politically entrenched, restrictive service delivery policies. Future epidemic control measures should include mitigation of negative side-effects on service provision and socio-economic determinants in PWID.
RESUMEN: La prevención del VIH/VHC entre las personas que se inyectan drogas (PWID) es de vital importancia para la salud pública. Nuestro objetivo fue evaluar el impacto de COVID-19 y las medidas de respuesta asociadas en los servicios de prevención del VIH/VHC y el estado socioeconómico de las PWID en sitios de alto riesgo de VIH. Se contactó con sitios con brotes recientes (20112019) de VIH entre PWID en Europa, América del Norte e Israel, que habían sido previamente identificados, a principios de mayo de 2020. De los 17 sitios invitados a participar, 13 aceptaron. Se prepararon informes cualitativos semiestructurados del sitio que cubrían los datos de marzo a mayo de 2020, analizados/codificados y confirmados con un cuestionario estructurado, en el que todos los sitios respondieron explícitamente a los 103 asuntos reportados en los informes cualitativos. El tratamiento de mantenimiento con opiáceos, los programas de agujas/jeringas y el tratamiento antirretroviral/tratamiento de la hepatitis C continuaron, pero con importantes reducciones y cambios operativos. Se reportaron aumentos en las sobredosis, dificultades generalizadas con las necesidades alimentarias y de higiene, interrupciones en el suministro de medicamentos y aumento de personas sin hogar. Los programas de servicios reformaron rápidamente las políticas restrictivas de prestación de servicios, establecidas desde hace mucho tiempo y políticamente arraigadas. Las futuras medidas de control de epidemias deben incluir la mitigación de los efectos secundarios negativos en la prestación de servicios y los determinantes socioeconómicos en las PWID.
Assuntos
COVID-19 , Usuários de Drogas , Infecções por HIV , Hepatite C , Abuso de Substâncias por Via Intravenosa , Humanos , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Preparações Farmacêuticas , Israel/epidemiologia , Determinantes Sociais da Saúde , COVID-19/epidemiologia , COVID-19/prevenção & controle , Hepatite C/epidemiologia , Hepatite C/prevenção & controle , Hepacivirus , Surtos de Doenças/prevenção & controle , Europa (Continente)/epidemiologiaRESUMO
Cryptosporidium is a protozoan parasite that causes the diarrhoeal disease, cryptosporidiosis. Although many species have been identified, the majority of human disease worldwide is caused by two species; Cryptosporidium parvum and Cryptosporidium hominis. In Australia, data from the National Notifiable Diseases Surveillance System (NNDSS) show that cryptosporidiosis outbreaks occur every few years. To better understand the transmission, trends and nature of cryptosporidiosis outbreaks in Western Australia, epidemiological and genomic data from three cryptosporidiosis outbreaks in 2003, 2007 and 2011 were reviewed. The 2007 outbreak was the largest (n = 607) compared with the outbreaks in 2003 (n = 404) and 2011 (n = 355). All three outbreaks appeared to have occurred predominantly in the urban metropolitan area (Perth), which reported the highest number of case notifications; increases in case notifications were also observed in rural and remote areas. Children aged 0-4 years and non-Aboriginal people comprised the majority of notifications in all outbreaks. However, in the 2003 and 2007 outbreaks, a higher proportion of cases from Aboriginal people was observed in the remote areas. Molecular data were only available for the 2007 (n = 126) and 2011 (n = 42) outbreaks, with C. hominis the main species identified in both outbreaks. Subtyping at the glycoprotein 60 (gp60) locus identified subtype IbA10G2 in 46.3% and 89.5% of C. hominis isolates typed, respectively, in the 2007 and 2011 outbreaks, with the IdA15G1 subtype was identified in 33.3% of C. hominis isolates typed in the 2007 outbreak. The clustering of cases with the IdA15G1 subtype in the remote areas suggests the occurrence of a concurrent outbreak in remote areas during the 2007 outbreak, which primarily affected Aboriginal people. Both the C. hominis IbA10G2 and IdA15G1 subtypes have been implicated in cryptosporidiosis outbreaks worldwide; its occurrence indicates that the mode of transmission in both the 2007 and 2011 outbreaks was anthroponotic. To better understand the epidemiology, sources and transmission of cryptosporidiosis in Australia, genotyping data should routinely be incorporated into national surveillance programmes.
Assuntos
Criptosporidiose/epidemiologia , Surtos de Doenças , Havaiano Nativo ou Outro Ilhéu do Pacífico , População Branca , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Criptosporidiose/etnologia , Cryptosporidium/classificação , Cryptosporidium/genética , Cryptosporidium/isolamento & purificação , DNA de Protozoário/isolamento & purificação , Fezes/parasitologia , Feminino , Humanos , Lactente , Masculino , Oocistos/isolamento & purificação , Estudos Retrospectivos , População Rural , População Urbana , Austrália Ocidental/epidemiologia , Adulto JovemRESUMO
Cryptosporidiosis is a gastroenteric disease caused by the protozoan parasite Cryptosporidium, which manifests primarily as watery diarrhoea. Transmitted via the faecal-oral route, infection with the parasite can occur through ingestion of water, food or other fomites contaminated with its infective oocyst stage. In the months of November and December 2012, there were 18 notified cases of cryptosporidiosis from Broome, Western Australia. The 5-year average for the Kimberley region for this period is <1 case. Interviews conducted by Broome local government staff on the notified cases revealed that 11/18 cases had been swimming at the Broome public swimming pool. Molecular analyses of extracted DNA performed on 8/18 microscopy-positive faecal samples from interviewed cases and three water samples from different locations at the hypervariable glycoprotein 60 (gp60) gene, identified the C. hominis IbA10G2 subtype in all human samples and one water sample.
Assuntos
Criptosporidiose/epidemiologia , Cryptosporidium/genética , DNA de Protozoário/análise , Surtos de Doenças , Fezes/parasitologia , Gastroenterite/epidemiologia , Piscinas , Adulto , Criança , Pré-Escolar , Cryptosporidium/isolamento & purificação , Gastroenterite/parasitologia , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Análise de Sequência de DNA , Água/parasitologia , Austrália Ocidental/epidemiologia , Adulto JovemRESUMO
In 2010, an outbreak of cyclosporiasis affected passengers and crew on two successive voyages of a cruise ship that departed from and returned to Fremantle, Australia. There were 73 laboratory-confirmed and 241 suspected cases of Cyclospora infection reported in passengers and crew from the combined cruises. A case-control study performed in crew members found that illness was associated with eating items of fresh produce served onboard the ship, but the study was unable conclusively to identify the responsible food(s). It is likely that one or more of the fresh produce items taken onboard at a south-east Asian port during the first cruise was contaminated. If fresh produce supplied to cruise ships is sourced from countries or regions where Cyclospora is endemic, robust standards of food production and hygiene should be applied to the supply chain.
Assuntos
Cyclospora/isolamento & purificação , Ciclosporíase/epidemiologia , Surtos de Doenças , Frutas/parasitologia , Navios , Verduras/parasitologia , Estudos de Casos e Controles , Ciclosporíase/diagnóstico , Fezes/parasitologia , Feminino , Humanos , Masculino , ViagemRESUMO
SHORT INTRODUCTION/BACKGROUND: Children affected by differences/disorders of sex development (DSDs) and their families are vulnerable to significant risks across developmental stages that threaten quality of life and psychosocial functioning. Accordingly, both experts in DSD treatment and patient advocacy groups have endorsed the incorporation of psychosocial care into interdisciplinary management of DSD conditions. OBJECTIVE: This study assessed psychosocial needs and received services reported by parents of children with DSD treated at two large US academic medical centers. Specifically, differences in parents' perceptions of psychosocial service needs were compared between those who received or did not receive interdisciplinary care that included psychology/social work professionals. STUDY DESIGN: In a cross-sectional study, sixty-four parents of children with DSD aged 0-19 years attending two major academic centers with interdisciplinary teams completed a questionnaire about their receipt and perception of 12 individual psychosocial services throughout their child's DSD treatment. RESULTS: Receipt of individual psychosocial services ranged from 27 to 81%. Most commonly, parents reported having a psychosocial provider explain medical terms and answer questions after talking with a doctor (81%), assist with words and terms to describe the condition and treatment (69%), and help navigate the hospital system (63%). Families positively endorsed psychosocial services, with 91-100% of services received rated as helpful. Parents of children who received care as part of an interdisciplinary team were significantly more likely to receive psychosocial services than those treated by single providers (e.g., urologists). Specific gaps in psychosocial care were noted in regard to access to mental health providers familiar with DSD, fertility counseling, and support with community advocacy (e.g., arranging for accommodations at the school or advocating on patient's behalf with the insurance company). Among families who had not received them, services most desired were assistance with words and terms to describe condition or treatment; explanation of medical terms and answering questions after meeting with a doctor; connection to resources such as books, pamphlets, websites, and support groups; and a central care coordinator for the medical team. DISCUSSION AND CONCLUSION: Families value psychosocial services but are far less likely to receive services if they are not seen in an interdisciplinary clinic visit that includes a psychosocial provider. Families desire but often lack mental health, advocacy, and fertility-related support. This study highlights the need for sustained psychosocial follow-up across development, even in the absence of pressing medical concerns, to provide support and anticipatory guidance as needs and issues evolve.
Assuntos
Transtornos do Desenvolvimento Sexual/terapia , Saúde Mental , Pais/psicologia , Psicoterapia/métodos , Qualidade de Vida , Desenvolvimento Sexual/fisiologia , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Transtornos do Desenvolvimento Sexual/psicologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto JovemRESUMO
Raw poultry products were purchased from the retail market place in two Australian states, New South Wales (n = 549) and South Australia (n = 310). The products sampled on a proportional volume basis were chicken portions with the skin off or skin on, in bulk or tray packs, and whole carcasses. They were collected from butcher shops, supermarkets, and specialty stores from urban areas during the winter (2005) and summer (2006) months. The samples were analyzed to determine the prevalence and concentration of Escherichia coli, Salmonella, and Campylobacter spp. in addition to total viable counts. Salmonella was found in 47.7 and 35.5% of retail chicken samples (35.3 and 21.9% were the less virulent Salmonella Sofia), at mean counts of -1.42 and -1.6 log MPN/cm2 in New South Wales and South Australia, respectively. Campylobacter was found in 87.8 and 93.2% of samples at mean counts of 0.87 and 0.78 log CFU/cm2, respectively. In both states in both seasons, the mean total viable count was 5 log CFU/cm2. On whole birds, E. coli was detected in all winter samples and on 92.9 and 85.7% of summer samples in New South Wales and South Australia, respectively; the log of the geometric mean per square centimeter was 0.5 in winter and slightly lower in summer. On chicken portions, E. coli was detected in around 90% of winter samples in both states, and in summer on 75.1 and 59.6% of samples in New South Wales and South Australia, respectively. The log of the geometric mean CFU per square centimeter for E. coli was 0.75 and 0.91 in winter, and 0.66 and 0.5 in summer in New South Wales and South Australia, respectively.
Assuntos
Campylobacter/isolamento & purificação , Qualidade de Produtos para o Consumidor , Escherichia coli/isolamento & purificação , Contaminação de Alimentos/análise , Carne/microbiologia , Salmonella/isolamento & purificação , Animais , Galinhas/microbiologia , Contagem de Colônia Microbiana , Comércio , Microbiologia de Alimentos , Humanos , Carne/normas , New South Wales , Controle de Qualidade , Estações do Ano , Pele/microbiologia , Austrália do SulRESUMO
BACKGROUND: Human cytomegalovirus (CMV) is a significant cause of morbidity and mortality among transplant recipients. Monitoring transplant recipients by CMV IgM serology has been questioned by several studies due to the reported insensitivity of serologic tests relative to antigen detection methods. METHODS: In this retrospective study, we have evaluated the performance of the new recombinant antigen-based Abbott AxSYM CMV IgM assay and compared it with CMV culture technique in a cohort of 40 liver transplant recipients who did not receive antiviral prophylaxis. RESULTS: The sensitivity, specificity, and positive and negative predictive values for detection of CMV disease by the AxSYM CMV IgM assay were 90.0%, 60.0%, 69.2%, and 85.7%, respectively, and by culture the values were 100%, 55.0%, 69.0%, and 100%, respectively. Detection of CMV IgM occurred before or at the time of CMV disease in only R+ recipients. CONCLUSION: Although this assay is a sensitive test for CMV-specific IgM, detection of CMV IgM preceded detection of virus by culture in patients only when the liver transplant recipient was CMV immune before transplantation (R+).
Assuntos
Antígenos Virais/imunologia , Citomegalovirus/imunologia , Imunoensaio/métodos , Imunoglobulina M/sangue , Transplante de Fígado , Anticorpos Antivirais/sangue , Estudos de Coortes , Humanos , Transplante de Fígado/imunologia , Proteínas Recombinantes de Fusão/imunologiaRESUMO
A total of 91 isolates of Treponema hyodysenteriae which were obtained from 62 piggeries located around Australia were typed by serology and by DNA restriction endonuclease analysis (REA). The isolates fell into eight serogroups, of which groups B and D were the most common. Isolates with different REA patterns were recognised within serogroups, whilst a few isolates with the same REA pattern were placed into different serogroups. Some of the latter isolates were either from the same piggery or from farms with epidemiological links, thus indicating the bacteria may have altered their antigenic properties. A total of 31 different REA patterns were recognised amongst the Australian isolates. These comprised eight major patterns, with four of these being subdivided on the basis of minor differences in banding. Where a number of isolates were obtained from individual piggeries these all had the same REA pattern, and in one piggery isolates with the same pattern were recovered over a five year period. Plasmid bands were observed in 70 of the Australian isolates (77%), and in six of the seven overseas isolates included in the study for comparison. These plasmids did not affect the REA pattern. Of the States from which substantial numbers of isolates were examined, the greatest number of different strains (12 amongst 19 piggeries) were found from Victoria, and there were 10 REA patterns in strains from 24 piggeries in Queensland. Despite the large total number of different strains of T. hyodysenteriae in Australia, only three were found in more than one State.
Assuntos
DNA Bacteriano/análise , Disenteria/veterinária , Doenças dos Suínos/microbiologia , Treponema/classificação , Infecções por Treponema/veterinária , Animais , Austrália , Disenteria/microbiologia , Eletroforese em Gel de Ágar , Plasmídeos , Mapeamento por Restrição , Sorotipagem , Suínos , Treponema/genética , Infecções por Treponema/microbiologiaRESUMO
Restriction endonuclease analysis (REA) was used to type eight well-characterised strains of Treponema hyodysenteriae originating from the U.K., Canada and the U.S.A., and 16 isolates from cases of swine dysentery in Western Australia (W.A.). Several of the W.A. isolates were also serotyped by the method of Baum and Joens (1979), and the two typing techniques were compared. REA typing was more discriminatory than serotyping, being able to distinguish strains within serotypes. The new technique was neither more difficult nor more time-consuming to perform than serotyping. Within the 16 W.A. isolates, three different REA patterns were identified, with common patterns found on different farms. The eight overseas strains had seven different REA patterns, all of which could be distinguished from the patterns of the W.A. isolates.
Assuntos
DNA Bacteriano/análise , Treponema/classificação , Animais , Disenteria/microbiologia , Disenteria/veterinária , Mapeamento por Restrição , Sorotipagem , Suínos , Doenças dos Suínos/microbiologia , Treponema/genética , Infecções por Treponema/microbiologia , Infecções por Treponema/veterináriaRESUMO
Multilocus enzyme electrophoresis (MEE) was used to examine the extent of genetic diversity amongst 98 isolates of Serpulina (Treponema) hyodysenteriae. The species contained four major genetic divisions (A, B, C and D) and 29 electrophoretic types (ETs). Division D was relatively distinct, being separated from the other three divisions by fixed allelic differences at an average of 6.6 of 15 enzyme loci. Electrophoretic differences were compared with results of DNA restriction endonuclease analysis (REA) and serological typing of the isolates. Most isolates with the same or similar REA banding patterns shared the same or similar ETs. This demonstrated that both techniques could be used as sensitive and specific methods of identifying closely related isolates. However, using MEE analysis, some isolates that had quite different REA patterns were found to be genetically closely related. Therefore ET designations had an advantage over REA patterns in that they were readily quantifiable as a means of estimating genetic relatedness between isolates. Most isolates that were genetically similar to each other were of the same serological group, but some antigenic types were widely distributed across the genetic divisions.
Assuntos
Brachyspira hyodysenteriae/genética , Variação Genética , Brachyspira hyodysenteriae/classificação , Brachyspira hyodysenteriae/enzimologia , Enzimas de Restrição do DNA/análise , DNA Bacteriano/genética , Eletroforese , Ligação Genética , SorotipagemRESUMO
An assessment was made of multilocus enzyme electrophoresis as a means of identifying and typing spirochaetes isolated from pigs. Using five enzyme systems, 36 isolates from Australia, the U.K. and the U.S.A. were divided into 12 electrophoretic types or multilocus genotypes, comprising four major, genetically distinct groups. All 26 isolates of Treponema hyodysenteriae fell into one group, members of which showed relatively little genetic diversity. Ten isolates of non-pathogenic spirochaetes fell into three genetically different groups. Although the technique was capable of typing organisms within the groups, it was not always as discriminatory as DNA-restriction endonuclease analysis. Examination of additional enzyme loci should increase the sensitivity of the method for typing and for overall assessment of genetic relationships between spirochaetes.
Assuntos
Alelos , Enzimas/análise , Treponema/classificação , Animais , Enzimas/genética , Variação Genética , Treponema/enzimologia , Treponema/genéticaRESUMO
A whole chromosomal DNA probe labelled with photobiotin was used in a dot blot hybridisation to identify DNA from isolates of Treponema hyodysenteriae, the aetiological agent of swine dysentery. The probe was evaluated using DNA from 13 isolates of T hyodysenteriae and 13 isolates of non-T hyodysenteriae spirochaetes recovered from pigs. The initial test had both a sensitivity and specificity of 92.3 per cent, although when it was repeated the specificity fell to 84.6 per cent. The test was helpful in distinguishing between T hyodysenteriae and other morphologically similar treponemes that are part of the normal flora in the large intestine of pigs. The probe could also be used to detect as little as 10 ng of purified DNA from T hyodysenteriae, or DNA from 2 x 10(6) bacterial cells lysed directly onto nitrocellulose.
Assuntos
Sondas de DNA , DNA Bacteriano/análise , Doenças dos Suínos/microbiologia , Treponema/isolamento & purificação , Infecções por Treponema/veterinária , Animais , Hibridização de Ácido Nucleico , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Suínos , Doenças dos Suínos/diagnóstico , Treponema/genética , Infecções por Treponema/diagnóstico , Infecções por Treponema/microbiologiaRESUMO
An outbreak of cysticercosis in a south-central Idaho custom feedlot reached a peak prevalence of 11% in January 1993 and extended from October 1992 through March 1993. Of 5,164 cattle slaughtered from this feedlot during the outbreak, 457 (9%) were cysticercosis infected. Total discounts on the infected cattle at slaughter cost the feedlot $154,400. Most evidence was suggestive of feed-borne transmission of Taenia saginata eggs to the cattle in the feedlot. By use of logistic regression analysis of feedlot records, significant (P = 0.004) association of cysticercosis prevalence at slaughter with days on feed was revealed. Similarly, a decline in cysticercosis prevalence was significantly (P < 0.001) related to the number of days cattle were fed a ration not containing potato byproduct. Although sources other than potato byproduct were systematically evaluated during the investigation, findings suggested that potato byproduct fed in this feedlot was contaminated with T saginata eggs.
Assuntos
Ração Animal/parasitologia , Doenças dos Bovinos/epidemiologia , Cisticercose/veterinária , Surtos de Doenças/veterinária , Parasitologia de Alimentos , Animais , Bovinos , Doenças dos Bovinos/etiologia , Cisticercose/epidemiologia , Cisticercose/etiologia , Feminino , Idaho/epidemiologia , Modelos Logísticos , Masculino , PrevalênciaAssuntos
Imunidade Materno-Adquirida , Infecções Pneumocócicas/prevenção & controle , Países em Desenvolvimento , Feminino , Infecções por Haemophilus/prevenção & controle , Vacinas Anti-Haemophilus , Haemophilus influenzae tipo b , Humanos , Recém-Nascido , Leite Humano/imunologia , Infecções Pneumocócicas/imunologia , GravidezRESUMO
Lipopolysaccharide (LPS) extracts obtained from Treponema hyodysenteriae of serogroups A, B, D and E, and from T. innocens were examined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), silver-staining, and immunoblotting with hyperimmune rabbit sera. All organisms possessed multiple LPS bands, but their position and number differed. Immunoblotting of LPS with grouping sera identified three or four major antigenic LPS components in the 10-42 kDa range in all organisms: these components were largely specific to each type-organism of a serogroup, and presumably represented group antigens. Although some minor cross-reactivity occurred between LPS from organisms in the different groups, this was insufficient to merit changes to the current LPS serogrouping system for T. hyodysenteriae. Besides this LPS 'complex', other higher-molecular-weight material which appeared to be a common component of the treponemes examined was present in low concentrations. Organisms with different serotypes within a serogroup apparently possessed common LPS bands, but also had unique LPS bands which may account for their serotype specificity. One 'untypable' organism lacked group-specific LPS and was thought to be a mutant of a group B organism. The loss of serogroup LPS by the isolate suggested that this material is an external component of the cell wall. The availability of an atypical organism lacking LPS components may facilitate further studies on the pathogenesis of swine dysentery.
Assuntos
Antígenos de Bactérias/análise , Lipopolissacarídeos/análise , Treponema/imunologia , Animais , Reações Cruzadas , Disenteria/microbiologia , Disenteria/veterinária , Eletroforese em Gel de Poliacrilamida , Immunoblotting , Prata , Coloração e Rotulagem , Suínos , Doenças dos Suínos/microbiologia , Infecções por Treponema/microbiologia , Infecções por Treponema/veterináriaRESUMO
Two Australian isolates of Treponema hyodysenteriae which did not fit within the current serological grouping system for these bacteria were examined by agarose gel double immunodiffusion tests (AGDP). Isolate Vic1 was serologically unique, and we propose that it becomes the type organism for a new sixth serological group of T. hyodysenteriae (Group F). Isolate Q1 was unusual in that lipopolysaccharide (LPS) extracted from it reacted strongly in AGDP with serum raised against the type organism for serogroup D (A1), and also weakly with serum raised against the type organism for serogroup B (WA1). The nature of this cross-reactivity was examined by using cross-absorbed antisera in AGDP, and by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. The pattern of serological cross-reactivity between Q1, A1 and WA1 was complex and was not fully defined, but the isolate Q1 apparently shared low molecular weight 'serogroup' LPS antigens with A1, and shared higher molecular weight LPS antigens with WA1. On this basis Q1 was designated as belonging to serogroup D, although it was recommended that this be qualified as D (B) to indicate the presence of weak cross-reactivity with serogroup B. Such serological cross-reactivity may have significance in relation to the development of immunity to T.hyodysenteriae. Isolate Q1 may be a potentially useful organism for vaccine development because of its ability to induce a good serological response to LPS of treponemes from both serogroups D and B.
Assuntos
Treponema/classificação , Animais , Austrália , Western Blotting , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Soros Imunes/imunologia , Imunodifusão , Lipopolissacarídeos/imunologia , SorotipagemRESUMO
Antisera were prepared in rabbits against seven well-characterized strains of Treponema hyodysenteriae of known serotype, and reacted in agarose gel double immunodiffusion tests (AGDP) with lipopolysaccharide (LPS) extracted from 18 Western Australian isolates of the organism. Eight isolates were provisionally typed by this method, but sera raised against one 'typed' and two 'untypable' local isolates reacted in an unexpected fashion with LPS from other local and type strains. Serum raised against the 'typed' local isolate reached with LPS from other previously untyped local isolates: this indicated the presence of more than one major LPS antigen amongst certain local isolates, and was confirmed by cross-absorption of sera. Sera raised against apparently untypable local isolates reacted with LPS from certain type organisms, thus suggesting the presence of complex antigenic relationships between LPS antigens. The serotyping system for T. hyodysenteriae which was proposed by Baum & Joens (1979) uses unabsorbed antisera and is made unworkable by these observations. Instead we propose placing organisms which share common LPS antigens into serogroups A to E, members of which are defined by their reactivity with unabsorbed sera raised against a type organism for the group. We suggest strains B78, WA1, B169, A1 and WA6 respectively as being the most suitable type organisms for the five serogroups identified so far. Isolates possessing additional unique LPS antigens can be regarded as serotypes within the serogroup. However the serotype of an isolate can only be established if antiserum is prepared against it, and this serum continues to react homologously after cross-absorption with bacteria from other serotypes within the serogroup.
Assuntos
Treponema/classificação , Animais , Imunodifusão/métodos , Lipopolissacarídeos/imunologia , Coelhos , Sorotipagem/métodos , Treponema/isolamento & purificaçãoRESUMO
Polymerase chain reaction (PCR) tests were established for detection of Serpulina hyodysenteriae, the agent of swine dysentery, and S. pilosicoli, the agent of intestinal spirochaetosis. Both reactions were specific when tested with DNA from 107 strains of various intestinal spirochaetes. For diagnostic use, faeces were plated to selective medium, and diatomaceous earth extraction used to obtain DNA prior to PCR. This procedure detected 10(3)-10(4) cells of either organism seeded into 0.2 g of faeces. When applied to 63 samples from pigs of eight piggeries naturally infected with either S. hyodysenteriae or S. pilosicoli, both PCRs were specific, more rapid, and detected more positive samples than did routine faecal culture and isolation.
Assuntos
Brachyspira hyodysenteriae/isolamento & purificação , Disenteria/veterinária , Enteropatias/veterinária , Reação em Cadeia da Polimerase , Infecções por Spirochaetales/veterinária , Doenças dos Suínos/diagnóstico , Animais , Disenteria/diagnóstico , Enteropatias/diagnóstico , Infecções por Spirochaetales/diagnóstico , SuínosRESUMO
Molecular characterization of a total of 52 human isolates of Salmonella typhi from Papua New Guinea was performed by using pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with three restriction endonucleases, XbaI (5'-TCTAGA-3'), AvrII (5'-CCTAGG-3'), and SpeI (5'-ACTAGT-3'). Of the 52 isolates tested, 11 were obtained from patients with fatal typhoid fever and 41 were obtained from patients with nonfatal disease. The 52 isolates showed limited genetic diversity as evidenced by only three different PFGE patterns detected following digestion with XbaI (patterns X1 to X3; F [coefficient of similarity] = 0.86 to 1.0), four patterns detected following digestion with AvrII (patterns A1 to A4; F =0.78 to 1.0), and two patterns detected following digestion with SpeI (patterns S1 and S2; F = 0.97 to 1.0). Of the 52 isolates, 37 were phage typed, and all belonged to phage type D2. All 11 isolates obtained from patients with fatal typhoid fever were identical (F = 1.0) and possessed the PFGE pattern combination X1S1A1, whereas the 41 isolates from patients with nonfatal typhoid fever had various PFGE pattern combinations, the most common being X2S1A2 (39%), X1S1A1 (24%), and X1S1A2 (15%). Thus, all the isolates from patients with the fatal disease had the X1 and A1 patterns, whereas the majority of the isolates from patients with nonfatal typhoid fever possessed the X2 and A2 patterns. The data suggest that there is an association among strains of S. typhi between genotype, as assessed by PFGE patterns, and the capability to cause fatal illness. Analysis of blood and fecal isolates of S. typhi from the same patient also indicated that some genetic changes occur in vivo during the course of infection.