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Molecular Characterisation of Salmonella enterica Serovar Sofia in AustraliaGan Teck Fong, Emily, xf_dksfwm@yahoo.com January 2008 (has links)
Despite its high isolation frequency in Australian chickens, S. II Sofia is rarely associated with animals or human salmonellosis as this serovar is avirulent in nature. The reason for its persistence and avirulence is unknown as very few studies have been conducted on the epidemiology and pathogenicity of this strain. This study details the various experimental methods utilised to investigate the genetic relatedness and molecular mechanisms involved in S. II Sofia pathogenesis. Using PFGE and Rep-PCR, the Australian S. II Sofia isolates were found to show limited genetic diversity and probably share a clonal relationship. A majority of the S. II Sofia isolates were not geographically restricted with the predominant pattern subtype spread out among the isolates from various states. Distribution and variation of the SPI-associated virulence genes within S. II Sofia was also examined. Based on RFLP and sequence analysis, most of the differences observed in SPI1 to SPI5 of S. II Sofia could be attributed to a loss or gain of restriction cleavage sites within these regions. However, a number of genes in SPI1, SPI2, SPI3 and SPI5 were found to have accumulated changes (mutations, insertions and deletions) that could have affected gene transcription and/or protein translation - these genes have been shown to be involved in different aspects of the virulence process. The avirulence of S. II Sofia is probably not the result of a single genetic change but rather a series of alterations to a large number of its virulence-associated genes. Plasmid-mediated virulence was also assessed in S. II Sofia isolates. Southern hybridisation with probes derived from the virulence plasmid of S. Typhimurium indicated either the total absence of the virulence plasmid or possible presence of a virulence plasmid containing major deletions. Clones were constructed with the missing spv operon using high-copy pCR®2.1 and low-copy pWSK29 plasmids and the adherence, invasion and intracellular survival of the mutant strain was evaluated in vitro. The presence of spvRABCD was shown to have no effect on intracellular survival and replication. Although the cloning of spv with pCR®2.1 was observed to significantly increase invasiveness of S. II Sofia, it was not capable of restoring the invasive ability of S. II Sofia to the level of pathogenic S. Typhimurium 82/6915. On the other hand, the uneven adherence and invasion ability of the other mutant strains appeared to be linked to the presence of pWSK29 and this observation is further supported by RT-PCR analysis of the clones - indicating that perhaps pWSK29 is not a suitable vector for this study. Wild-type S. II Sofia isolates are unlikely to regain full pathogenicity because of the numerous mutations in many important virulence genes: even the chance acquisition of a virulence factor (e.g. spvRABCD) is not sufficient to completely restore S. II Sofia virulence. Therefore, S. II Sofia should not be considered similar to other Salmonella spp. when monitoring Salmonellae in food samples.
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Identificación de serogrupos patogenos de leptospira spp. en caninos domésticosSiuce Moreno, Juan José January 2014 (has links)
La leptospirosis es una zoonosis bacteriana de gran impacto en la salud pública a nivel mundial. Los perros y otros animales, pueden infectarse, sufrir la enfermedad, constituyendo así, un factor importante en la diseminación de la bacteria hacia humanos. La infección es causada por cualquiera de los 250 serovares patógenos, de los 25 serogrupos de Leptospira spp. El estudio tuvo como objetivo identificar a los serogrupos de Leptospira spp. presentes en caninos domésticos. Para ello, se obtuvieron 305 muestras de suero sanguíneo, de perros con diagnóstico clínico presuntivo de Leptospirosis, mayores de 6 meses de edad, no vacunados o con un tiempo mayor a seis meses desde la última vacunación contra Leptospirosis. Las muestras fueron remitidas por Médicos Veterinarios al Laboratorio de Microbiología – Sección Bacteriología de la Facultad de Medicina Veterinaria de la Universidad Nacional Mayor de San Marcos, provenientes de 31 distritos de Lima Metropolitana. Se realizó la Prueba de Microaglutinación (MAT), estableciéndose títulos ≥1/100 de serorreactividad como seropositivos, utilizando cepas de referencia de los 25 serogrupos, incluyendo al nuevo serogrupo Iquitos serovar varillal 10, aislado y reportado en casos humanos en Perú. Se detectaron 177 seropositivos (58.03%), de los cuales 31 (10.16%) fueron coaglutinaciones. Los serogrupos de mayor frecuencia fueron: Iquitos (46/305; 15.08%), Tarassovi (37/305; 12.13%), Canicola (37/305; 12.13%), Australis (14/305; 4.59%), Icterohaemorrhagiae (13/305; 4.26%), Pomona (12/305; 3.93%), Mini (10/305; 3.28%) y Ballum (8/305; 2.62%). No se identificó serorreactores a los serugrupos Bataviae, Celledoni, Hebdomadis, Lousiana, Panama, Ranarum, Sarmin.
Palabras claves: Perros, leptospirosis, leptospira, MAT, serovar, serogrupo / Leptospirosis is an important bacterial zoonosis on worldwide. Dogs and other animals can be infected and suffered the disease, they constituting an important role in the spread of the bacteria to humans. The infection is caused by any of the 250 pathogenic serovars, grouped in 25 serogroups of Leptospira spp. The aim of this study was to identify the serogroups of Leptospira spp. circulating in domestic dogs. For this, 305 serum samples were obtained from dogs, who had a presumptive clinical diagnosis of Leptospirosis, over 6 months old, unvaccinated or more than six months since the last vaccination against Leptospirosis, The samples were submitted by veterinarians to Microbiology Lab - Bacteriology, Faculty of Veterinary Medicine of Universidad Nacional Mayor de San Marcos, from 31 districts of Lima. The microagglutination test (MAT) was performed, establishing seroreactivity titles ≥ 1/100 as seropositive using reference strains of the 25 serogroups, including the new serogroup Iquitos, serovar Varillal, Var 10 strain, isolated and reported human outbreaks in Peru. 177 seropositive samples (58.03%) were detected, 31 of them (10.16%) were co-agglutinations. Seropositive reacted against 18 serogroups, the most frequent were: Iquitos (46/305; 15.08%), Tarassovi (37/305; 12.13%), Canicola (37/305; 12.13%), Australis (14/305; 4.59%), Icterohaemorrhagiae (13/305; 4.26%), Pomona (12/305; 3.93%), Mini (10/305; 3.28%) and Ballum (8/305; 2.62%). There were no seroreactors to serogroups: Bataviae, Celledoni, Hebdomadis, Lousiana, Panama, Ranarum, and Sarmin.
Keywords: Dog, leptospirosis, leptospira, MAT, serovar, serogroup.
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Considerations for Automating Salmonella Serovar Identification within an Electronic Public Health Reporting EnvironmentAlexander, Jeffry Chanen 08 September 2015 (has links)
CDC's requirements for Salmonella surveillance reporting include submission of serovars from the recognized naming scheme, Kauffmann-White (K-W), using identifiers curated by the Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT®). Translating the serotype formula of a Salmonella isolate to the correct identifier has been a multistep manual process for users. Our goal was to determine whether a degree of automation could be achieved using an ontology based on K-W.
We investigated information artifacts presently available, namely K-W, SNOMED CT and CDC's Public Health Information Network - Vocabulary Access and Distribution System (PHIN-VADS). As SNOMED CT creates identifiers and associates them with serovar names, we performed detailed analysis on its coverage of K-W. An overall error rate of 13.1% included simple omissions and transcription errors. We limited our assessment of K-W and PHIN-VADS to the functional characteristics of the resources they distribute. K-W creates serovar names but does not provide identifiers. PHIN-VADS includes the identifiers but not antigenic formulae for most isolates. In summary, neither K-W nor PHIN-VADS contained all information users require.
Two different ontology prototypes were developed. Prototype I placed K-W serovars as terminal nodes in the hierarchy and these were given logic-based definitions. Prototype II added isolate classes as serovar subtypes. Only the isolate classes had complete logical definitions. Both prototypes were logically sound and functioned as expected. Prototype I paralleled existing SNOMED CT content but required more robust description logic than currently employed in SNOMED CT. Prototype II was more compatible with current functionality of SNOMED CT but created identifiers that would not meet current requirements for public health reporting.
Prototype I was fully populated as the Salmonella Serotype Designation Ontology (SSDO). As it stands, SSDO reliably places isolates in the appropriate classes, with few and predictable exceptions. Although SNOMED CT cannot accommodate its functionality at this time, SSDO can serve as the basis for a stand-alone application.
Ultimately whether by improving functionality of existing systems or providing a framework for an ancillary automated system, this work should facilitate real-time reporting and analysis of surveillance data that will prevent new or reduce severity of infectious disease outbreaks. / Ph. D.
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Avaliação da suscetibilidade antimicrobiana e do perfil de macrorrestrição do DNA de isolados humanos de Salmonella serovar Typhimurium fagotipo 193, no período de 1970 a 2008 / Evaluation of antimicrobial susceptibility and macrorestriction DNA of human isolates of Salmonella serovar Typhimurium phage type 193 in the period 1970 to 2008Eliane Moura Falavina dos Reis 09 June 2011 (has links)
Para analisar cepas de Salmonella ser. Typhimurium isoladas de processos entéricos e extraintestinais humanos ocorridos no período de 1970 a 2008 de diferentes regiões do país foram selecionadas, com base nos registros contidos no banco de dados do Laboratório de Enterobactérias do IOC/FIOCRUZ, RJ, amostras do fagotipo prevalente 193, visando precipuamente o reconhecimento de clones epidêmicos. Foram selecionadas 553 cepas de Salmonella ser. Typhimurium fagotipo 193 representadas por 91, 65, 70 e 327 amostras referentes as décadas de 70, 80, 90 e ao período de 2000 a 2008, respectivamente. Na análise global da sensibilidade destas cepas, 52% apresentaram um ou mais marcadores de resistência a antibióticos incluídos no perfil ACSSuT. Este perfil de resistência completo foi verificado em 20,9% dos isolados, sendo os 21,9% restantes, sensíveis a todas as drogas testadas, especialmente no período de 2000 a 2008, representadas por 121 amostras (37,0%) em relação as 327 culturas dessa época. O maior percentual de resistência foi observado nas amostras da década de 70 (99%) sendo o perfil ACSSuT detectado em 35,2% dos isolados, ressaltando-se que todas as amostras foram isoladas de processos gastroentéricos ocorridos na cidade de São Paulo. Ao longo das quatro décadas de estudo, descreve-se um ponto de ruptura entre a prevalência de resistência e a suscetibilidade na transição entre as décadas de 80 e 90. Embora o número de isolados de Salmonella ser. Typhimurium fagotipo 193 tenha aumentado no último período considerado, o percentual de mono e multirresistência aos antimicrobianos se situou em nível elevado (63,0%). A análise do polimorfismo obtido após macrorrestrição com a enzima XbaI revelou que cepas isoladas na década de 90 apresentaram elevado percentual de similaridade (≥85%) com cepas isoladas recentemente (período de 2000-2008), sendo agrupadas nos mesmos subclusters. Por outro lado, as cepas da década de 70 inserem-se em subclusters independentes, embora o percentual de similaridade entre tais subclusters e os demais seja ≥70%; o mesmo sendo observado para as cepas isoladas durante a década de 80. Em conclusão, este estudo mostrou que a prevalência de isolados humanos de Salmonella ser. Typhimurium fagotipo 193 no Brasil vem progredindo desde a década de 1990, enquanto a detecção do modelo R (ACSSuT) está diminuindo e a avaliação através da PFGE indicou a presença de multiplicidade de perfis de macrorrestrição no fagotipo 193, entretanto com elevados percentuais de similaridade entre si, sugerindo alguma clonalidade, tendo em vista o período entre o isolamento e a análise / To analyze strains of Salmonella ser. Typhimurium isolated from human cases of enteric and extraintestinal occurred during the period 1970 to 2008 of different regions of Brazil were selected, based on records in the database from Enterobacteria Laboratory of IOC / FIOCRUZ, RJ, samples prevalent phage type 193 in order to recognition of epidemic clones. We selected 553 strains of Salmonella ser. Typhimurium phage type 193 represented by 91, 65, 70 and 327 samples concerning the 1970s, 1980s, 1990s and the period from 2000 to 2008, respectively. In a global analysis of the sensitivity of these strains, 52% had one or more antibiotic resistance markers included in the profile ACSSuT. This resistance profile was found complete in 20.9% of isolates and the remaining 21.9%, sensitive to all drugs tested, especially in the period 2000 to 2008, represented by 121 samples (37.0%) compared the 327 cultures of that time. The highest percentage of resistance was observed in the samples of the 70 (99%) being the profile ACSSuT detected in 35.2% of isolates, emphasizing that all strains were isolated from gastrointestinal processes occurring in São Paulo city. Over the four decades of study, we describe a breaking point between the prevalence of resistance and susceptibility in the transition between the 1980s and 1990s. Although the number of isolates of Salmonella ser. Typhimurium phage type 193 has increased in the last period, the percentage of mono-and multidrug resistance to antimicrobial agents stood at high level (63.0%). The analysis of polymorphism obtained after macrorestriction with the enzyme XbaI showed that isolates in the 1990s showed a high percentage of similarity (≥ 85%) with strains isolated recently (2000-2008) and are grouped in the same subclusters. Moreover, the strains of the 1970s fall into subclusters independent, although the percentage of similarity between such subclusters and the other is ≥ 70%, the same was observed for the strains isolated during the 1980s. In conclusion, this study showed that the prevalence of human isolates of Salmonella ser. Typhimurium phage type 193 in Brazil has been progressing since the 1990s, while the detection of R model (ACSSuT) is decreasing and evaluation by PFGE indicated the presence of multiple profiles macrorestriction in phage type 193, however with high percentages of similarity, suggesting some clonality in view the period between isolation and analysis
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Avaliação da suscetibilidade antimicrobiana e do perfil de macrorrestrição do DNA de isolados humanos de Salmonella serovar Typhimurium fagotipo 193, no período de 1970 a 2008 / Evaluation of antimicrobial susceptibility and macrorestriction DNA of human isolates of Salmonella serovar Typhimurium phage type 193 in the period 1970 to 2008Eliane Moura Falavina dos Reis 09 June 2011 (has links)
Para analisar cepas de Salmonella ser. Typhimurium isoladas de processos entéricos e extraintestinais humanos ocorridos no período de 1970 a 2008 de diferentes regiões do país foram selecionadas, com base nos registros contidos no banco de dados do Laboratório de Enterobactérias do IOC/FIOCRUZ, RJ, amostras do fagotipo prevalente 193, visando precipuamente o reconhecimento de clones epidêmicos. Foram selecionadas 553 cepas de Salmonella ser. Typhimurium fagotipo 193 representadas por 91, 65, 70 e 327 amostras referentes as décadas de 70, 80, 90 e ao período de 2000 a 2008, respectivamente. Na análise global da sensibilidade destas cepas, 52% apresentaram um ou mais marcadores de resistência a antibióticos incluídos no perfil ACSSuT. Este perfil de resistência completo foi verificado em 20,9% dos isolados, sendo os 21,9% restantes, sensíveis a todas as drogas testadas, especialmente no período de 2000 a 2008, representadas por 121 amostras (37,0%) em relação as 327 culturas dessa época. O maior percentual de resistência foi observado nas amostras da década de 70 (99%) sendo o perfil ACSSuT detectado em 35,2% dos isolados, ressaltando-se que todas as amostras foram isoladas de processos gastroentéricos ocorridos na cidade de São Paulo. Ao longo das quatro décadas de estudo, descreve-se um ponto de ruptura entre a prevalência de resistência e a suscetibilidade na transição entre as décadas de 80 e 90. Embora o número de isolados de Salmonella ser. Typhimurium fagotipo 193 tenha aumentado no último período considerado, o percentual de mono e multirresistência aos antimicrobianos se situou em nível elevado (63,0%). A análise do polimorfismo obtido após macrorrestrição com a enzima XbaI revelou que cepas isoladas na década de 90 apresentaram elevado percentual de similaridade (≥85%) com cepas isoladas recentemente (período de 2000-2008), sendo agrupadas nos mesmos subclusters. Por outro lado, as cepas da década de 70 inserem-se em subclusters independentes, embora o percentual de similaridade entre tais subclusters e os demais seja ≥70%; o mesmo sendo observado para as cepas isoladas durante a década de 80. Em conclusão, este estudo mostrou que a prevalência de isolados humanos de Salmonella ser. Typhimurium fagotipo 193 no Brasil vem progredindo desde a década de 1990, enquanto a detecção do modelo R (ACSSuT) está diminuindo e a avaliação através da PFGE indicou a presença de multiplicidade de perfis de macrorrestrição no fagotipo 193, entretanto com elevados percentuais de similaridade entre si, sugerindo alguma clonalidade, tendo em vista o período entre o isolamento e a análise / To analyze strains of Salmonella ser. Typhimurium isolated from human cases of enteric and extraintestinal occurred during the period 1970 to 2008 of different regions of Brazil were selected, based on records in the database from Enterobacteria Laboratory of IOC / FIOCRUZ, RJ, samples prevalent phage type 193 in order to recognition of epidemic clones. We selected 553 strains of Salmonella ser. Typhimurium phage type 193 represented by 91, 65, 70 and 327 samples concerning the 1970s, 1980s, 1990s and the period from 2000 to 2008, respectively. In a global analysis of the sensitivity of these strains, 52% had one or more antibiotic resistance markers included in the profile ACSSuT. This resistance profile was found complete in 20.9% of isolates and the remaining 21.9%, sensitive to all drugs tested, especially in the period 2000 to 2008, represented by 121 samples (37.0%) compared the 327 cultures of that time. The highest percentage of resistance was observed in the samples of the 70 (99%) being the profile ACSSuT detected in 35.2% of isolates, emphasizing that all strains were isolated from gastrointestinal processes occurring in São Paulo city. Over the four decades of study, we describe a breaking point between the prevalence of resistance and susceptibility in the transition between the 1980s and 1990s. Although the number of isolates of Salmonella ser. Typhimurium phage type 193 has increased in the last period, the percentage of mono-and multidrug resistance to antimicrobial agents stood at high level (63.0%). The analysis of polymorphism obtained after macrorestriction with the enzyme XbaI showed that isolates in the 1990s showed a high percentage of similarity (≥ 85%) with strains isolated recently (2000-2008) and are grouped in the same subclusters. Moreover, the strains of the 1970s fall into subclusters independent, although the percentage of similarity between such subclusters and the other is ≥ 70%, the same was observed for the strains isolated during the 1980s. In conclusion, this study showed that the prevalence of human isolates of Salmonella ser. Typhimurium phage type 193 in Brazil has been progressing since the 1990s, while the detection of R model (ACSSuT) is decreasing and evaluation by PFGE indicated the presence of multiple profiles macrorestriction in phage type 193, however with high percentages of similarity, suggesting some clonality in view the period between isolation and analysis
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Modulating the gut microbiota with a synthetic stool “MET-1”: protective effects in animal models of antibiotic associated colitisMartz, SARAH-LYNN 02 October 2013 (has links)
Thesis (Master, Microbiology & Immunology) -- Queen's University, 2013-09-29 21:18:18.966
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Study of the dissemination of cefoxitin-resistant Salmonella enterica serovar Heidelberg from human, abattoir poultry and retail poultry sourcesEdirmanasinghe, Romaine Cathy Shalini 15 September 2016 (has links)
This study characterized Salmonella enterica serovar Heidelberg from human, abattoir poultry and retail poultry isolates to examine the molecular relationships of cefoxitin resistance between these groups. A total of 147 S. Heidelberg (70 cefoxitin-resistant and 77 cefoxitin-susceptible) isolates were studied. All cefoxitin-resistant isolates were also resistant to amoxicillin-clavulanic acid, ampicillin, ceftiofur and ceftriaxone, and all contained the CMY-2 gene. Pulsed-field gel electrophoresis typing illustrated that 93.9% isolates clustered together with ≥ 90% similarity. Core genome analysis using whole genome sequencing identified 12 clusters of isolates with zero to four single nucleotide variations. These clusters consisted of cefoxitin-resistant and susceptible human, abattoir poultry and retail poultry isolates. Analysis of CMY-2 plasmids from cefoxitin-resistant isolates revealed all belonged to incompatibility group I1. Analysis of plasmid sequences using WGS revealed high identity (95-99%) to a previously described plasmid (pCVM29188_101) found in Salmonella Kentucky. When compared to pCVM29188_101, all sequenced cefoxitin-resistant isolates were found to carry one of ten possible variant plasmids. The discovery of several clusters of isolates from different sources with zero to four SNVs suggests that transmission between human, abattoir poultry and retail poultry sources may be occurring. The classification of newly sequenced plasmids into one of ten sequence variant types suggests transmission of a common CMY-2 plasmid amongst S. Heidelberg with variable genetic backgrounds. / October 2016
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Adaptive responses of salmonella enterica serovar enteritidis ATCC 4931 biofilms to nutrient laminar flow and benzalkonium chloride treatmentIllathu, Anilkumar Mangalappalli 12 December 2007
<i>Salmonella enterica serovar Enteritidis</i> is an important biofilm-forming food-borne pathogen. This study examined the adaptive responses of <i>Salmonella serovar Enteritidis</i> biofilms to different environmental conditions such as flow velocity and benzalkonium chloride (BC) treatment. The influence of a 10-fold difference in nutrient laminar flow velocity on the dynamics of biofilm formation and protein expression profiles was compared. The mode of development and architecture of low-flow and high-flow biofilms were distinct. Exopolymer composition of the two biofilms was also different. However, no major shift in protein expression was seen between the biofilms, nor were there any stress response proteins involved. The biofilms altered their architecture in response to flow, presumably assuming a structure that minimized overall biofilm stress. An empirically-determined shear-inducing flow was applied on high-flow biofilms, fractionating the biofilms into shearable and non-shearable regions. Length:width indices of cells from the two biofilm regions, as well as planktonic cells from biofilm effluent and continuous culture were determined to be 3.2, 2.3, 2.2, and 1.7, respectively. Expression of proteins involved in cold-shock response, adaptation, and broad regulatory functions in the shearable region, and expression of protein involved in heat-shock response and chaperonin function in the non-shearable region indicated that the physiological status of cells in two biofilm regions was also distinct. The development of biofilm adaptive resistance to BC was then examined. Adapted biofilms survived a lethal BC challenge and re-grew, whereas unadapted biofilms did not. Proteins up-regulated following adaptation included those involved in energy metabolism, amino acid and protein biosynthesis, nutrient-transportation, adaptation, detoxification, and 1,2-propanediol degradation. A putative universal stress protein was also up-regulated. Cold-shock response, stress response, and detoxification are suggested to play roles in adaptive resistance to BC. Functional differences in adaptive response and survival of plankonic and biofilm cells adapted to BC were also studied. The proportion of BC-adapted biofilm cells that survived a lethal BC exposure and heat-shock was significantly higher than that of BC-adapted planktonic cells. Enhanced biofilm-specific up-regulation of various proteins, coupled with alterations in cell surface roughness and shift in fatty acid composition are proposed to function in the enhanced survival of BC-adapted biofilm cells, relative to BC-adapted planktonic cells.<p>It is concluded that biofilms adapt to the stress conditions by means of community, cellular, and sub-cellular level responses. These adaptive responses help the biofilms to enhance their ability for survival in the nature, especially those formed in critical environments such as healthcare facilities, the food industry, and households.
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Adaptive responses of salmonella enterica serovar enteritidis ATCC 4931 biofilms to nutrient laminar flow and benzalkonium chloride treatmentIllathu, Anilkumar Mangalappalli 12 December 2007 (has links)
<i>Salmonella enterica serovar Enteritidis</i> is an important biofilm-forming food-borne pathogen. This study examined the adaptive responses of <i>Salmonella serovar Enteritidis</i> biofilms to different environmental conditions such as flow velocity and benzalkonium chloride (BC) treatment. The influence of a 10-fold difference in nutrient laminar flow velocity on the dynamics of biofilm formation and protein expression profiles was compared. The mode of development and architecture of low-flow and high-flow biofilms were distinct. Exopolymer composition of the two biofilms was also different. However, no major shift in protein expression was seen between the biofilms, nor were there any stress response proteins involved. The biofilms altered their architecture in response to flow, presumably assuming a structure that minimized overall biofilm stress. An empirically-determined shear-inducing flow was applied on high-flow biofilms, fractionating the biofilms into shearable and non-shearable regions. Length:width indices of cells from the two biofilm regions, as well as planktonic cells from biofilm effluent and continuous culture were determined to be 3.2, 2.3, 2.2, and 1.7, respectively. Expression of proteins involved in cold-shock response, adaptation, and broad regulatory functions in the shearable region, and expression of protein involved in heat-shock response and chaperonin function in the non-shearable region indicated that the physiological status of cells in two biofilm regions was also distinct. The development of biofilm adaptive resistance to BC was then examined. Adapted biofilms survived a lethal BC challenge and re-grew, whereas unadapted biofilms did not. Proteins up-regulated following adaptation included those involved in energy metabolism, amino acid and protein biosynthesis, nutrient-transportation, adaptation, detoxification, and 1,2-propanediol degradation. A putative universal stress protein was also up-regulated. Cold-shock response, stress response, and detoxification are suggested to play roles in adaptive resistance to BC. Functional differences in adaptive response and survival of plankonic and biofilm cells adapted to BC were also studied. The proportion of BC-adapted biofilm cells that survived a lethal BC exposure and heat-shock was significantly higher than that of BC-adapted planktonic cells. Enhanced biofilm-specific up-regulation of various proteins, coupled with alterations in cell surface roughness and shift in fatty acid composition are proposed to function in the enhanced survival of BC-adapted biofilm cells, relative to BC-adapted planktonic cells.<p>It is concluded that biofilms adapt to the stress conditions by means of community, cellular, and sub-cellular level responses. These adaptive responses help the biofilms to enhance their ability for survival in the nature, especially those formed in critical environments such as healthcare facilities, the food industry, and households.
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A study of group B streptococcus in Brisbane : the epidemiology, detection by PCR assay and serovar prevalenceTaylor, Karen Leigh January 2006 (has links)
The neonate is still at risk of acquiring Group B Streptococcus (GBS) infection upon delivery even with the implementation of early onset GBS neonatal disease preventative protocols. GBS was reported as the most prevalent organism causing neonatal morbidity and mortality in the USA and Australia in the 1990s. GBS is also known to cause disease in children, women, the immunocompromised adult and the elderly, but it is the preterm neonates who are at greatest risk of GBS neonatal disease. The aim of this study was to determine the prevalence of lower genital tract (LGT) colonisation with GBS in Brisbane women of child bearing age. We also aimed: (i) to compare the GBS LGT prevalence rate of Indigenous and non Indigenous women; (ii) to determine whether previously reported risk factors for LGT colonisation with GBS were also risk factors associated with GBS colonisation of women in this study; (iii) to further develop and optimise a rapid PCR assay that could detect maternal LGT GBS colonisation; and (iv) to serotype the GBS strains that were isolated from pregnant and non pregnant women who participated in this study. This study recruited 374 women of childbearing age attending public medical providers and found an overall GBS prevalence of 98/374 (26.2%) for these Brisbane women, a rate higher than previously reported in Australia. When the GBS prevalence for pregnant women (25.6%) was compared to non pregnant women (27.2%) they were similar. We also compared the GBS LGT colonisation rate of women attending different medical providers. The GBS LGT prevalence rate for pregnant women attending the Mater was 36/118 (30.5%), whilst those women attending the Redlands Hospital antenatal clinic had a LGT GBS prevalence rate of only 7/53 (13.2%). By comparison, the LGT GBS prevalence rate for non pregnant women attending Biala Sexual Health clinic was 21/69 (30.4%) and 34/127 (26.8%) of women attending the Brisbane Family Planning Queensland were also GBS positive. The seven women recruited from Inala community centre tested negative for GBS LGT colonisation. The LGT GBS prevalence of Australian Aboriginal women was 5/22 (22.7%), a rate which was not significantly different from non-Aboriginal women 78/288 (27.1%). Established early onset GBS neonatal disease preventative policies have been recently revised. The CDC now recommends that all pregnant women are screened for LGT GBS colonisation during late gestation, and that any GBS isolates be tested for resistance to antibiotics if the GBS positive women have an allergy to penicillin. Queensland's Department of Health recommend that Queensland medical agencies implement a non screening based preventative protocol, where clinicians monitor: women prior to labour for reported risk factors associated with maternal GBS colonisation: women in labour for 'obstetric risk factors'. A number of risk factors have previously been reported in association with GBS LGT colonisation. However, in this current study we found that only one risk factor was significantly associated with current GBS: previous reported LGT GBS colonisation was significantly associated with maternal LGT GBS colonisation reported in this study. Women who previously tested positive for GBS were significantly more likely to be GBS positive in subsequent tests (OR 4.7; 95%CI, 1.8-12.5) compared to women with no previous history of GBS colonisation. An assessment of adverse pregnancy outcomes, preterm deliveries, and GBS colonisation data was made. It was established that 30 women had previously given birth to one or more preterm neonates and of these 30 women, nine (30%) of them tested positive for GBS in this current study. Of the 71 women who had given birth to neonates and who had suffered an adverse pregnancy outcome 25.3% also tested positive for GBS in this current study. GBS was identified in up to 30% of all mothers who had delivered their neonate preterm, 27.4% of women who had previously suffered miscarriages and 16.7% of women who had previously had stillbirths. In this study we found that Australian Aboriginal women also had a greater risk of delivering neonates who suffered from an adverse pregnancy outcome in comparison to all other women. Twenty one of the 22 Aboriginal women had previously been pregnant at least once, and nine (42.9%) of these women had at least one prior adverse pregnancy outcome while seven (33.3%) of these women had previously delivered at least one neonate preterm. Of the 21 Aboriginal women who had a previous pregnancy more than half the total number of Aboriginal women (11/21) had either delivered one or more neonates preterm or had suffered from one or more adverse pregnancy outcomes. When the incidence of adverse pregnancy outcomes was compared for Aboriginal and all other women the results were surprising. Overall, this study found 216 women including Aboriginal women had previously been pregnant and of these women 71 (32.8%) of them suffered an adverse pregnancy outcome. By comparison, only 62 of 195 (31.8%) non Aboriginal women but nine out of 21 (41.9%) Australian Aboriginal women suffered from a previous adverse pregnancy outcome. The clinical LGT GBS isolates found in this study of Brisbane women were typed and all nine GBS serotypes plus non typeable GBS serotypes were detected. Seventy women tested GBS culture positive and vaginal and/or perianal samples obtained from these women were evaluated. GBS serotype III was the serotype most frequently isolated from this total population, from 47.4% of pregnant women and 51.7% of non pregnant women. From some women only a single GBS serotype was isolated: in these women we found that GBS serotype III (50%) was the predominant isolate, followed by GBS serotype Ia isolated from 16.7% women. In addition 4.2% of women were colonised with GBS serotypes; Ib, II and V, whilst GBS serotypes IV and VII were isolated from 2.1% women. Non typeable GBS strains confirmed by latex agglutination tests accounted for 11.9% of all strains isolated from these Brisbane women. This study identified multiple serovars in 15 clinical samples and found that 22 (31.4%) women were colonised with mixed GBS serotypes in samples collected from both vaginal and perianal regions. In five women the combination of serotypes III/Ia were identified and in other women combinations of serotypes III/II, III/IV, III/V, III/VIII, Ia/IV and Ib/NT were also detected. In two instances three serotype combinations were detected in samples from one woman and these included serotypes III/Ib/II and III/Ia/Ib. Isolates were also typed for women who were colonised in both vaginal and perianal regions and it was found that only 10 participants had identical isolates in both regions. GBS serotype III was the predominant serotype detected in women tested in this study and this is the serotype that has previously been associated with invasive infections in neonates. GBS neonatal disease is a world wide economic, health and social burden affecting different ethnic groups and is preventable. Currently no vaccine technology is available for the prevention of GBS neonatal disease and the most effective EOGND preventative protocol would be to test for maternal GBS colonisation during labour, or screen women for GBS at >36 weeks' gestation and administer intrapartum antibiotic prophylaxis (IAP) to all women who tested positive for GBS. In this current study we utilised a rapid bsp PCR assay to detect LGT GBS colonisation in women of child bearing age. The PCR assay identified 62.5% of all vaginal and perianal positive culture GBS samples. The specificity of the PCR assay was 89% while the positive and negative predictive values were 56.8% and 91.1% respectively. This PCR assay using the current parameters is not an effective GBS detection assay but could be further optimised in the near future. This PCR assay could be an effective test in the future with the development of an alternative DNA extraction method to InstaGene (BioRad). However, this PCR assay if used in conjunction with the current culture method is able to detect a further 8.9% of women colonised with asymptomatic GBS. Brisbane women aged between 26 to 35 years who are pregnant and who are attending public health care agencies are at greatest risk of being colonised with GBS. No disparity was identified when ethnicity or social standing were assessed. The overall results of this study demonstrate that the LGT GBS prevalence rate in Brisbane women is 26.2% but this rate was higher at 30.5% for women attending a Brisbane sexual health clinic and for pregnant women attending the Mater Mothers' antenatal clinic. GBS serovar III has been identified as the dominant serovar in our population group and this strain has been reported as the major cause of GBS disease in neonates and infants aged to three months. Disparity (11.1%) was reported when the incidence of adverse pregnancy outcomes amongst Aboriginal women was compared to non Aboriginal women. From the outcomes of this study it has been suggested that Queensland adopt a screening based GBS preventative protocol. It has also been suggested that an Australian wide GBS prevention strategy may further reduce the incidence of neonatal disease.
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