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
During infectious disease episodes, pathogens express distinct subsets of virulence factors which allow them to adapt to different environments. Hence, genes that are expressed or upregulated in vivo are implicated in...During infectious disease episodes, pathogens express distinct subsets of virulence factors which allow them to adapt to different environments. Hence, genes that are expressed or upregulated in vivo are implicated in pathogenesis. We used in vivo induced antigen technology (IVIAT) to identify antigens which are expressed during infection with Salmonella enterica serovar Typhi. We identified 7 in vivo induced (IVI) antigens, which included BcfD (a fimbrial structural subunit), GrxC (a glutaredoxin 3), SapB (an ABC-type transport system), T3663 (an ABC-type uncharacterized transport system), T3816 (a putative rhodanese-related sulfurtransferase), T1497 (a probable TonB-dependent receptor) and T3689 (unknown function). Of the 7 identified antigens, 5 antigens had no cross-immunoreactivity in adsorbed control sera from healthy subjects. These 5 included BcfD, GrxC, SapB, T3663 and T3689. Antigens identified in this study are potential targets for drug and vaccine development and may be utilized as diagnostic agents.展开更多
BACKGROUND:Evidence exists of a link between chronic infection by Salmonella typhi(S.typhi) and the development of gallbladder cancer(GBC),but several studies from endemic regions contradict its role in the etiopathog...BACKGROUND:Evidence exists of a link between chronic infection by Salmonella typhi(S.typhi) and the development of gallbladder cancer(GBC),but several studies from endemic regions contradict its role in the etiopathogenesis of GBC.This study used various tools to assess the prevalence of S.typhi in patients with GBC and gallstone disease(GSD) in this region with a high incidence of GBC.METHODS:S.typhi was detected in tissue and bile by PCR and culture and in serum by the Widal test and indirect hemagglutination assay(IHA).PCR with two pairs of S.typhi specific primers(flagellin gene H1d and SOP E gene) could detect 0.6 ng of S.typhi DNA.Fifty-four patients with GBC(cases) were matched with 54 patients with GSD(controls).RESULTS:Of the 54 cases,24(44.44%) were positive on the Widal test and 12(22.22%) on IHA,compared to 13(24.07%) and 5(9.26%) respectively in the controls.Eighteen(33.33%) cases showed a positive result on PCR(tissue) and 2 on PCR(bile) vs.none in the controls.Bile culture revealed no Salmonella colonies in either cases or controls.Only 3 cases were positive for Salmonella on tissue culture compared to none in the controls.The sensitivity of PCR(tissue) relative to the Widal test,IHA,culture(bile and tissue) and PCR(bile) was 100% vs.66.67%,11.11%,and 11.11%,and the specificity was 83.33% vs.100%,100%,and 100%,respectively.CONCLUSIONS:S.typhi is significantly associated with GBC compared to GSD(33% vs.0%).PCR appears to be the most specific diagnostic tool,the gold standard for S.typhi in tissue samples.展开更多
Salmonella （S.） typhi is an important intracellular pathogen. Among the more than 2,300 closely-related Salmonella serovars bacteria recognized, S. typhi is the only one that is pathogenic exclusively for humans, in...Salmonella （S.） typhi is an important intracellular pathogen. Among the more than 2,300 closely-related Salmonella serovars bacteria recognized, S. typhi is the only one that is pathogenic exclusively for humans, in whom it causes typhoid or enteric fever. The pathogen has been around for many years and many studies have been done in an effort to combat it. Molecular and biologic features of S. typhi and host factors and immune responses involved in Salmonella invasion have been extensively studies. Vaccines that have been developed most notably are Vi polysaccharide and Ty21a. However, as the results show, there is still a long way to go. It is also shown that multi-drug resistance has occurred to the few available antibiotics. More and more studies have shown that Salmonella can be used as a vaccine vector carrying antigens of other pathogens. This has been promising in that the immune system can be elicited in response to both the Salmonella bacteria and the antigen of the pathogen in question. This review aims to highlight some of the milestones attained in the fight against the disease from the time S. typhi was seen as a pathogen causing typhoid fever to the use of Salmonella as a vaccine vector. Cellular ＆ Molecular Immunology.展开更多
Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in...Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in Mamakkal,Tamil Nadu.India.Both strains were grown in LB(Luria Bertani) medium supplemented with various concentration of NaCl(0.1- 0.7M) respectively.The effecl of osmolar stress was determined at molecular level by PCR using MCR 06 and MCR07 primers corresponding to ompR with chromosomal DNA of S.typhi SS3 and SS5 strains.Attenuation by osmolar stress results in deletion mutation of the.S.typhi slrains was determined by agglutination assays,precipitation method.SDS PAGE analysis and by animal models.Results:The 799 bp amplified ompR gene product from wild type S.typhi SS3 and SS5 illustrate the presence of virulent gene.Interestingly,there was only a 282 bp amplified product from S.typhi SS3 and SS5 grown in the presence of 0.5.0.6 and 0.7 M NaCl.This illustrates the occurrence of deletion mutation in ompR gene al high concentration of NaCl.Furthermore,both the wildtype and mutant S.typhi outer membrane SDS-PAGF.profile reveals the differences in the expression of ompF.ompC and ompA proteins.In mice,wild type and mutant strains lethal dose(LD_(50)) were determined.The mice died within 72 h when both the wild type strains were injected intraperitoneally with 3 log CFU-mL^(-1).When the mice were injected with the mutants in same dosage,no clinical symptoms were observed;whereas the serum antibodv litre was elicited within two weeks indicated that the mutants have the ability to induce protective humoral immune response.These results suggest that S.typhi SS3 and SS5 may bo used as good candidate strains for the development of live attenuated vaccine against salmonellosis.Conclusions:This study demonstrates that the S.typhi strains were allenualed and could be good vaccine candidates in future.展开更多
In this work bactericidal study of silver nanoparticles was taken up in combination with two standard antibiotics, ampicillin and gentamycin, for Salmonella Typhi. The antibacterial activities of antibiotics were incr...In this work bactericidal study of silver nanoparticles was taken up in combination with two standard antibiotics, ampicillin and gentamycin, for Salmonella Typhi. The antibacterial activities of antibiotics were increased in the presence of AgNPs against test strains. The higher enhancing effect was observed for ampicillin in comparison to gentamicin against test strains. Silver nanoparticles were synthesized elctrolytically using silver wire of 99% purity as anode and carbon rod wrapped with LDPE as cathode. Silver nitrate [of Merck] of 0.01N is used as an electrolyte. Here tea extract is added as capping and mild reducing agent. The polyphenols theaflavins and thearubigins, present in tea perform the role of stabilizing or capping agents due to their bulky and steric nature. A brown coloured colloidal solution of silver nanoparticles is obtained. The as-synthesized silver nanoparticles were characterized using XRD, TEM and UV-Vis spectroscopy.展开更多
Objective: Infectious diseases such as typhoid fever lead to the formation of free radicals which can damage the body. Many medicinal plants have antioxidant molecules that neutralize free radicals. The present work e...Objective: Infectious diseases such as typhoid fever lead to the formation of free radicals which can damage the body. Many medicinal plants have antioxidant molecules that neutralize free radicals. The present work evaluated the antioxidant activity and histopathological effects of the dichloromethane fraction of Dichrocephala integrifolia in Salmonella typhi-infected rats.Methods: The S. typhi-infected rats concurrently received daily doses of D. integrifolia extract at doses of 25, 50 and 100 mg/kg body weight or ciprofloxacin(5 mg/kg body weight) for 15 days. Body temperature was measured daily during infection and treatment periods. At the end of treatment period, the animals were sacrificed and biological responses including hematological parameters, superoxide dismutase and catalase activities, and glutathione, malondialdehyde and nitric oxide concentrations were evaluated.Results: The elevated body temperature induced by infection was significantly decreased in animals treated with 25, 50 or 100 mg/kg of the extract. Platelet levels decreased slightly in infected rats, while treatment with the dichloromethane fraction of D. integrifolia significantly increased platelet levels;this response was greater than that elicited by ciprofloxacin. The doses of 50 and 100 mg/kg of the dichloromethane fraction of D. integrifolia notably decreased monocyte and neutrophil values. Activity of superoxide dismutase and catalase and levels of glutathione in the tissues of treated animals were increased significantly(P < 0.01), while malondialdehyde and nitric oxide levels were significantly decreased(P < 0.01), following treatment with the dichloromethane fraction of D. integrifolia.Conclusion: The results of this study show that the dichloromethane fraction of D. integrifolia has protective effects against a series of pathological conditions initiated by oxidation and tissue damage in the course of a S. typhi infection.展开更多
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
Antimicrobial resistance has become a major challenge to the treatment and prevention of infections resulted in high morbidity and mortality globally. The inappropriate or abuse of antibiotics in animal farming is a k...Antimicrobial resistance has become a major challenge to the treatment and prevention of infections resulted in high morbidity and mortality globally. The inappropriate or abuse of antibiotics in animal farming is a key factor and thus led to the emergence of bacteria resistance and subsequent transfer of resistance genes to humans through the food chain. This study was to determine the prevalence of Salmonella typhi (S. typhi) and Escherichia coli (E. coli) isolated from various meat and fish samples and their susceptibility patterns against five commonly used antibiotics in Ghana (Ciprofloxacin 5 μg, Amoxicillin-clavulanic acid 20/10 μg, Imipenem 10 μg, Tetracycline 30 μg and Ceftazidime 30 μg). A total of 105 meat and fish samples were obtained from Tema and Prampram markets and bacteria isolation was carried out using appropriate selective microbial culture media and various biochemical methods for identification. The susceptibility patterns were determined using the Kirby-Bauer disk diffusion method and the results were interpreted using the CLSI 2020 guidelines. The results revealed a total of 56 bacterial isolates comprising 14 E. coli (25%) and 42 S. typhi (75%) isolated from the meat and fish samples. The antibiogram study showed a high resistance rate (88.64%) of S. typhi isolates to amoxicillin-clavulanic acid and tetracycline (97.73%). A moderate susceptibility of the isolates was obtained with imipenem (53.27%). All the E. coli isolates were resistant to tetracycline (100%) and demonstrated 78.57% and 50% resistance to amoxicillin-clavulanic acid and ceftazidime respectively. A total of 78.57% of the E. coli isolates and 68.18% of S. typhi isolates showed multidrug resistance. The multiple antibiotic resistance (MAR) index for all the isolates ranged from 0.2 to 1.00 with two S. typhi isolates and one E. coli isolate having a MAR index of 1.00 signifying total resistance to all the 5 antibiotics tested. In conclusion, E. coli and S. typhi isolated from the meat samples exhibited high rate of res展开更多
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.
基金Supported by the National Natural Science Foundation of China (Grant No. 30500435)
文摘During infectious disease episodes, pathogens express distinct subsets of virulence factors which allow them to adapt to different environments. Hence, genes that are expressed or upregulated in vivo are implicated in pathogenesis. We used in vivo induced antigen technology (IVIAT) to identify antigens which are expressed during infection with Salmonella enterica serovar Typhi. We identified 7 in vivo induced (IVI) antigens, which included BcfD (a fimbrial structural subunit), GrxC (a glutaredoxin 3), SapB (an ABC-type transport system), T3663 (an ABC-type uncharacterized transport system), T3816 (a putative rhodanese-related sulfurtransferase), T1497 (a probable TonB-dependent receptor) and T3689 (unknown function). Of the 7 identified antigens, 5 antigens had no cross-immunoreactivity in adsorbed control sera from healthy subjects. These 5 included BcfD, GrxC, SapB, T3663 and T3689. Antigens identified in this study are potential targets for drug and vaccine development and may be utilized as diagnostic agents.
文摘BACKGROUND:Evidence exists of a link between chronic infection by Salmonella typhi(S.typhi) and the development of gallbladder cancer(GBC),but several studies from endemic regions contradict its role in the etiopathogenesis of GBC.This study used various tools to assess the prevalence of S.typhi in patients with GBC and gallstone disease(GSD) in this region with a high incidence of GBC.METHODS:S.typhi was detected in tissue and bile by PCR and culture and in serum by the Widal test and indirect hemagglutination assay(IHA).PCR with two pairs of S.typhi specific primers(flagellin gene H1d and SOP E gene) could detect 0.6 ng of S.typhi DNA.Fifty-four patients with GBC(cases) were matched with 54 patients with GSD(controls).RESULTS:Of the 54 cases,24(44.44%) were positive on the Widal test and 12(22.22%) on IHA,compared to 13(24.07%) and 5(9.26%) respectively in the controls.Eighteen(33.33%) cases showed a positive result on PCR(tissue) and 2 on PCR(bile) vs.none in the controls.Bile culture revealed no Salmonella colonies in either cases or controls.Only 3 cases were positive for Salmonella on tissue culture compared to none in the controls.The sensitivity of PCR(tissue) relative to the Widal test,IHA,culture(bile and tissue) and PCR(bile) was 100% vs.66.67%,11.11%,and 11.11%,and the specificity was 83.33% vs.100%,100%,and 100%,respectively.CONCLUSIONS:S.typhi is significantly associated with GBC compared to GSD(33% vs.0%).PCR appears to be the most specific diagnostic tool,the gold standard for S.typhi in tissue samples.
基金supported by grants from National Natural Science Foundation of China(30670098,30470087,and 30570070)the Major State Basic Research Development Program of China(“973”project 2005CB522901 and 2006CB504300)a grant from Hubei Province Science Technology Department(2006ABD007).
文摘Salmonella （S.） typhi is an important intracellular pathogen. Among the more than 2,300 closely-related Salmonella serovars bacteria recognized, S. typhi is the only one that is pathogenic exclusively for humans, in whom it causes typhoid or enteric fever. The pathogen has been around for many years and many studies have been done in an effort to combat it. Molecular and biologic features of S. typhi and host factors and immune responses involved in Salmonella invasion have been extensively studies. Vaccines that have been developed most notably are Vi polysaccharide and Ty21a. However, as the results show, there is still a long way to go. It is also shown that multi-drug resistance has occurred to the few available antibiotics. More and more studies have shown that Salmonella can be used as a vaccine vector carrying antigens of other pathogens. This has been promising in that the immune system can be elicited in response to both the Salmonella bacteria and the antigen of the pathogen in question. This review aims to highlight some of the milestones attained in the fight against the disease from the time S. typhi was seen as a pathogen causing typhoid fever to the use of Salmonella as a vaccine vector. Cellular ＆ Molecular Immunology.
文摘Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in Mamakkal,Tamil Nadu.India.Both strains were grown in LB(Luria Bertani) medium supplemented with various concentration of NaCl(0.1- 0.7M) respectively.The effecl of osmolar stress was determined at molecular level by PCR using MCR 06 and MCR07 primers corresponding to ompR with chromosomal DNA of S.typhi SS3 and SS5 strains.Attenuation by osmolar stress results in deletion mutation of the.S.typhi slrains was determined by agglutination assays,precipitation method.SDS PAGE analysis and by animal models.Results:The 799 bp amplified ompR gene product from wild type S.typhi SS3 and SS5 illustrate the presence of virulent gene.Interestingly,there was only a 282 bp amplified product from S.typhi SS3 and SS5 grown in the presence of 0.5.0.6 and 0.7 M NaCl.This illustrates the occurrence of deletion mutation in ompR gene al high concentration of NaCl.Furthermore,both the wildtype and mutant S.typhi outer membrane SDS-PAGF.profile reveals the differences in the expression of ompF.ompC and ompA proteins.In mice,wild type and mutant strains lethal dose(LD_(50)) were determined.The mice died within 72 h when both the wild type strains were injected intraperitoneally with 3 log CFU-mL^(-1).When the mice were injected with the mutants in same dosage,no clinical symptoms were observed;whereas the serum antibodv litre was elicited within two weeks indicated that the mutants have the ability to induce protective humoral immune response.These results suggest that S.typhi SS3 and SS5 may bo used as good candidate strains for the development of live attenuated vaccine against salmonellosis.Conclusions:This study demonstrates that the S.typhi strains were allenualed and could be good vaccine candidates in future.
文摘In this work bactericidal study of silver nanoparticles was taken up in combination with two standard antibiotics, ampicillin and gentamycin, for Salmonella Typhi. The antibacterial activities of antibiotics were increased in the presence of AgNPs against test strains. The higher enhancing effect was observed for ampicillin in comparison to gentamicin against test strains. Silver nanoparticles were synthesized elctrolytically using silver wire of 99% purity as anode and carbon rod wrapped with LDPE as cathode. Silver nitrate [of Merck] of 0.01N is used as an electrolyte. Here tea extract is added as capping and mild reducing agent. The polyphenols theaflavins and thearubigins, present in tea perform the role of stabilizing or capping agents due to their bulky and steric nature. A brown coloured colloidal solution of silver nanoparticles is obtained. The as-synthesized silver nanoparticles were characterized using XRD, TEM and UV-Vis spectroscopy.
文摘Objective: Infectious diseases such as typhoid fever lead to the formation of free radicals which can damage the body. Many medicinal plants have antioxidant molecules that neutralize free radicals. The present work evaluated the antioxidant activity and histopathological effects of the dichloromethane fraction of Dichrocephala integrifolia in Salmonella typhi-infected rats.Methods: The S. typhi-infected rats concurrently received daily doses of D. integrifolia extract at doses of 25, 50 and 100 mg/kg body weight or ciprofloxacin(5 mg/kg body weight) for 15 days. Body temperature was measured daily during infection and treatment periods. At the end of treatment period, the animals were sacrificed and biological responses including hematological parameters, superoxide dismutase and catalase activities, and glutathione, malondialdehyde and nitric oxide concentrations were evaluated.Results: The elevated body temperature induced by infection was significantly decreased in animals treated with 25, 50 or 100 mg/kg of the extract. Platelet levels decreased slightly in infected rats, while treatment with the dichloromethane fraction of D. integrifolia significantly increased platelet levels;this response was greater than that elicited by ciprofloxacin. The doses of 50 and 100 mg/kg of the dichloromethane fraction of D. integrifolia notably decreased monocyte and neutrophil values. Activity of superoxide dismutase and catalase and levels of glutathione in the tissues of treated animals were increased significantly(P < 0.01), while malondialdehyde and nitric oxide levels were significantly decreased(P < 0.01), following treatment with the dichloromethane fraction of D. integrifolia.Conclusion: The results of this study show that the dichloromethane fraction of D. integrifolia has protective effects against a series of pathological conditions initiated by oxidation and tissue damage in the course of a S. typhi infection.
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Antimicrobial resistance has become a major challenge to the treatment and prevention of infections resulted in high morbidity and mortality globally. The inappropriate or abuse of antibiotics in animal farming is a key factor and thus led to the emergence of bacteria resistance and subsequent transfer of resistance genes to humans through the food chain. This study was to determine the prevalence of Salmonella typhi (S. typhi) and Escherichia coli (E. coli) isolated from various meat and fish samples and their susceptibility patterns against five commonly used antibiotics in Ghana (Ciprofloxacin 5 μg, Amoxicillin-clavulanic acid 20/10 μg, Imipenem 10 μg, Tetracycline 30 μg and Ceftazidime 30 μg). A total of 105 meat and fish samples were obtained from Tema and Prampram markets and bacteria isolation was carried out using appropriate selective microbial culture media and various biochemical methods for identification. The susceptibility patterns were determined using the Kirby-Bauer disk diffusion method and the results were interpreted using the CLSI 2020 guidelines. The results revealed a total of 56 bacterial isolates comprising 14 E. coli (25%) and 42 S. typhi (75%) isolated from the meat and fish samples. The antibiogram study showed a high resistance rate (88.64%) of S. typhi isolates to amoxicillin-clavulanic acid and tetracycline (97.73%). A moderate susceptibility of the isolates was obtained with imipenem (53.27%). All the E. coli isolates were resistant to tetracycline (100%) and demonstrated 78.57% and 50% resistance to amoxicillin-clavulanic acid and ceftazidime respectively. A total of 78.57% of the E. coli isolates and 68.18% of S. typhi isolates showed multidrug resistance. The multiple antibiotic resistance (MAR) index for all the isolates ranged from 0.2 to 1.00 with two S. typhi isolates and one E. coli isolate having a MAR index of 1.00 signifying total resistance to all the 5 antibiotics tested. In conclusion, E. coli and S. typhi isolated from the meat samples exhibited high rate of res
