Background: Donated blood contaminated with S. Typhi can cause post-transfusion sepsis. This study aimed to determine the correlation between some risk factors of typhoid fever and seroprevalence of antibodies against...Background: Donated blood contaminated with S. Typhi can cause post-transfusion sepsis. This study aimed to determine the correlation between some risk factors of typhoid fever and seroprevalence of antibodies against S. Typhi among blood donors. Methodology: Following informed consent, socio-demographic and information on risk factors of typhoid infection was obtained using pre-structured questionnaires from 400 apparently healthy blood donors at the Tema General Hospital. Blood was also collected for serology and cultured for identification of pathogens by standard bacteriological method. Results: Blood culture did not reveal any S. Typhi isolate out of the tested 400 (348 males and 52 females) samples from apparently healthy blood donors. However, IgM and IgG antibody seroprevalence of 9.3% and 3.5% were detected. Age group of 17 - 24 years was the highest risk group, persons with a history of typhoid infection, and sources of drinking water were major risk factors for typhoid infection. It was also observed that prevalence of IgM was highest among new donors (62.2%), but lower in donors with a history of 1 to 3 blood donations (32.4%) and least among regular donors (>3 donations (5.4%)). In addition, typhoid prevention awareness and typhoid knowledge (knowledge about typhoid transmission) among the donors were poor (4.3% and 5.9% respectively). Conclusions: This study has shown an overall seroprevalence of 9% and 3.5% for IgM and IgG antibodies respectively among blood donors in the Tema area in Ghana. We advocate for the mandatory screening of donor units intended for transfusion for S. Typhi. Furthermore, there is an urgent need for the health education of all persons in Ghana on preventive measures and the spread of S. Typhi.展开更多
pR_(ST98) is a large and conjugative resistant plasmid(R plasmid)of 98.6 mega-dalton from multi-drug resistant Salmonella typhi(S.typhi),which was classified to incompatibility group C(Inc C).It has been found that pR...pR_(ST98) is a large and conjugative resistant plasmid(R plasmid)of 98.6 mega-dalton from multi-drug resistant Salmonella typhi(S.typhi),which was classified to incompatibility group C(Inc C).It has been found that pR_(ST98) made its host bacteria not only antibiotic resistant but also more virulent.In this study we explored the possibility of plasmid pR_(ST98) in S.typhi carrying the Salmonella plasmid virulence gene-spv.The plasmid pR_(ST98) was isolated, purified and then digested by nine restriction endonucleases to make the plasmid enzyme profile.Spv-specific PCR and Southern blot were applied to identify the virulence gene on pR_(ST98).The amplified spv fragments spvR and spvB were cloned into pGEM-T EASY and then the DNA sequences were analysed.The fragments of pR_(ST98) digested by endonucleases Bgl Ⅱ,Pst Ⅰ and Sac Ⅱ were identified,which may be useful for molecular analysis and further epidemiological surveillance of pR_(ST98).The results of PCR and Southern blot showed that spv homologous genetic sequence which had been found in all pathogenesis Salmonella spp.except S.typhi was also presented on pR_(ST98).The ORF of spvR and spvB of pR_(ST98) were 894 bp and 1,776 bp,respectively.They have more than 99% homology with that of spvR and spvB on virulence plasmid in S.typhmurium.The genotype research on pR_(ST98) revealed that there is a plasmid carrying genes responsible for drug resistance and virulence in S.typhi.This is the first report for such kind chimerical plasmid in S.typhi.Cellular & Molecular Immunology.2005;2(2):136-140.展开更多
Resistome is a cluster of microbial genes encoding proteins with necessary functions to resist the action of antibiotics.Resistome governs essential and separate biological functions to develop resistance against anti...Resistome is a cluster of microbial genes encoding proteins with necessary functions to resist the action of antibiotics.Resistome governs essential and separate biological functions to develop resistance against antibiotics.The widespread clinical and nonclinical uses of antibiotics over the years have combined to select antibiotic-resistant determinants and develop resistome in bacteria.At present,the emergence of drug resistance because of resistome is a significant problem faced by clinicians for the treatment of Salmonella infection.Antibiotic resistome is a dynamic and ever-expanding component in Salmonella.The foundation of resistome in Salmonella is laid long before;therefore,the antibiotic resistome of Salmonella is reviewed,discussed,and summarized.We have searched the literature using PubMed,MEDLINE,and Google Scholar with related key terms(resistome,Salmonella,antibiotics,drug resistance)and prepared this review.In this review,we summarize the status of resistance against antibiotics in S.typhi,highlight the seminal work in the resistome of S.typhi and the genes involved in the antibiotic resistance,and discuss the various methods to identify S.typhi resistome for the proactive identification of this infection and quick diagnosis of the disease.展开更多
文摘Background: Donated blood contaminated with S. Typhi can cause post-transfusion sepsis. This study aimed to determine the correlation between some risk factors of typhoid fever and seroprevalence of antibodies against S. Typhi among blood donors. Methodology: Following informed consent, socio-demographic and information on risk factors of typhoid infection was obtained using pre-structured questionnaires from 400 apparently healthy blood donors at the Tema General Hospital. Blood was also collected for serology and cultured for identification of pathogens by standard bacteriological method. Results: Blood culture did not reveal any S. Typhi isolate out of the tested 400 (348 males and 52 females) samples from apparently healthy blood donors. However, IgM and IgG antibody seroprevalence of 9.3% and 3.5% were detected. Age group of 17 - 24 years was the highest risk group, persons with a history of typhoid infection, and sources of drinking water were major risk factors for typhoid infection. It was also observed that prevalence of IgM was highest among new donors (62.2%), but lower in donors with a history of 1 to 3 blood donations (32.4%) and least among regular donors (>3 donations (5.4%)). In addition, typhoid prevention awareness and typhoid knowledge (knowledge about typhoid transmission) among the donors were poor (4.3% and 5.9% respectively). Conclusions: This study has shown an overall seroprevalence of 9% and 3.5% for IgM and IgG antibodies respectively among blood donors in the Tema area in Ghana. We advocate for the mandatory screening of donor units intended for transfusion for S. Typhi. Furthermore, there is an urgent need for the health education of all persons in Ghana on preventive measures and the spread of S. Typhi.
文摘pR_(ST98) is a large and conjugative resistant plasmid(R plasmid)of 98.6 mega-dalton from multi-drug resistant Salmonella typhi(S.typhi),which was classified to incompatibility group C(Inc C).It has been found that pR_(ST98) made its host bacteria not only antibiotic resistant but also more virulent.In this study we explored the possibility of plasmid pR_(ST98) in S.typhi carrying the Salmonella plasmid virulence gene-spv.The plasmid pR_(ST98) was isolated, purified and then digested by nine restriction endonucleases to make the plasmid enzyme profile.Spv-specific PCR and Southern blot were applied to identify the virulence gene on pR_(ST98).The amplified spv fragments spvR and spvB were cloned into pGEM-T EASY and then the DNA sequences were analysed.The fragments of pR_(ST98) digested by endonucleases Bgl Ⅱ,Pst Ⅰ and Sac Ⅱ were identified,which may be useful for molecular analysis and further epidemiological surveillance of pR_(ST98).The results of PCR and Southern blot showed that spv homologous genetic sequence which had been found in all pathogenesis Salmonella spp.except S.typhi was also presented on pR_(ST98).The ORF of spvR and spvB of pR_(ST98) were 894 bp and 1,776 bp,respectively.They have more than 99% homology with that of spvR and spvB on virulence plasmid in S.typhmurium.The genotype research on pR_(ST98) revealed that there is a plasmid carrying genes responsible for drug resistance and virulence in S.typhi.This is the first report for such kind chimerical plasmid in S.typhi.Cellular & Molecular Immunology.2005;2(2):136-140.
文摘Resistome is a cluster of microbial genes encoding proteins with necessary functions to resist the action of antibiotics.Resistome governs essential and separate biological functions to develop resistance against antibiotics.The widespread clinical and nonclinical uses of antibiotics over the years have combined to select antibiotic-resistant determinants and develop resistome in bacteria.At present,the emergence of drug resistance because of resistome is a significant problem faced by clinicians for the treatment of Salmonella infection.Antibiotic resistome is a dynamic and ever-expanding component in Salmonella.The foundation of resistome in Salmonella is laid long before;therefore,the antibiotic resistome of Salmonella is reviewed,discussed,and summarized.We have searched the literature using PubMed,MEDLINE,and Google Scholar with related key terms(resistome,Salmonella,antibiotics,drug resistance)and prepared this review.In this review,we summarize the status of resistance against antibiotics in S.typhi,highlight the seminal work in the resistome of S.typhi and the genes involved in the antibiotic resistance,and discuss the various methods to identify S.typhi resistome for the proactive identification of this infection and quick diagnosis of the disease.
