Objective To investigate the characteristic of integrons and the relationship between integrons and antimicrobial resistance in Shigella spp. Methods Ninety Shigella strains (83 S. flexneri and 7 S. sonnei) were iso...Objective To investigate the characteristic of integrons and the relationship between integrons and antimicrobial resistance in Shigella spp. Methods Ninety Shigella strains (83 S. flexneri and 7 S. sonnei) were isolated from the stools of patients in China. Susceptibility to 8 antimicrobials was tested for all isolated strains. PCR, RFLP and sequencing analysis of integrons were applied to all of them. Results High prevalence of multi‐drug resistance (95.6%) was identified. Of the isolates 79 (87.8%) carried integrase genes of class 1 integron (3.3%), class 2 integron (10.0%) or both (74.4%). No intI3 was detected in the tested isolates. The prevalence of intI2 was significantly higher in isolates with multi‐drug resistance to at least 3 antibiotics than that in isolates with resistance to 2 and less antibiotics (P0.05). Gene cassettes dfrA17‐aadA5, dfrA12‐orfF‐aadA2 of class 1 integron and dfrA1‐sat1‐aadA1 of class 2 integron were identified. Conclusion The class 2 integron may play a role in the emergence of multi‐drug resistance in Shigella spp.展开更多
Introduction: Salmonella and Shigella are gram-negative bacilli that are resistant to most antibiotics and play an important role in an etiology of diarrhea disease. The aim of the study was to determine the prevalenc...Introduction: Salmonella and Shigella are gram-negative bacilli that are resistant to most antibiotics and play an important role in an etiology of diarrhea disease. The aim of the study was to determine the prevalence of Salmonella spp and Shigella spp isolated from stool and blood samples in the city of N’Djamena. Materials and Method: This was a prospective study conducted in the four district hospitals of N’Djamena from 14 July 2022 to 31 December 2022. A questionnaire form was drawn up to collect the information sent to the study patients. The samples were analyzed at the CHU de la Mère et de l’Enfant, Labo-Redes laboratory according to their protocols and the standard of the antibiogram committee of the French microbiology society. Results: Of the 803 biological samples analyzed, 39 were positive for Salmonella spp and Shigella spp, including 15 for Salmonella and 24 for Shigella, giving an overall prevalence rate of 4.85%. Borehole water, uncooked food and lack of access to a latrine constitute a risk of being infected by Salmonella spp and Shigella spp species. Of the 8 antibiotics tested, Salmonella spp and Shigella spp strains showed good sensitivity to nalidixic acid (100% for Salmonella and 90 for Shigella) and to ciprofloxacin (90.9% for Salmonella and 75% for Shigella). Resistance to ampicillin was found in 81.81% of Salmonella species and 78.57% of Shigella species, as was resistance to chloramphenicol (81.81% of Salmonella species and 67.85% of Shigella species). Similarly, cleanliness of the service and equipment is an essential factor in preventing Salmonella and Shigella infections.展开更多
Jute mallow is a nutritious leafy vegetable. The leaves are rich in proteins, vitamins and essential amino acids. Molecular characterization of Jute mallow with focus on improvement of leaf yield is scarcely reported....Jute mallow is a nutritious leafy vegetable. The leaves are rich in proteins, vitamins and essential amino acids. Molecular characterization of Jute mallow with focus on improvement of leaf yield is scarcely reported. In the present study, inter sequence simple repeats (ISSR) molecular markers were employed to assess genetic diversity and relationships of 83 accessions of Jute mallow from different parts of Africa and Asia conserved at the World Vegetable Center East and Southern Africa. A total of 89 bands were amplified by 8 ISSR primers. Number of polymorphic bands per primer ranged from 2 to 6 with an average of 2.75 bands per primer. Polymorphic information content (PIC) values ranged from 0.390 to 0.760 with average of 0.53. Average Nei’s gene diversity (h) and Shannon’s information index (I) were 0.335 and 0.494 respectively. The highest pairwise genetic distance was 0.431 observed in a population from East Africa accessions. PC1 and PC2 axis explained 21.69% and 11.66% of the total variation respectively. UPGMA cluster analysis grouped the accessions into six main clusters at genetic similarity coefficient of 0.53 as standard value for classification. These results have important implications for jute mallow breeding and conservation.展开更多
Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms ...Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms of Fragaria spp. from January 2021 to February 2022. The plant was introduced in Cameroon in 2018. There are 13 varieties of Fragaria spp. currently cultivated. Among these 13 varieties, eleven are hybrids of Fragaria x ananassa (“Amiga”, “Amine”, “Camarosa”, “Chandler”, “Charlotte”, “Elsanta”, “Gariguette”, “Madame Moutot”, “Ostara”, “Ruby gem” and “San Andreas”), and two of the hybrids of Fragaria vesca (“Maestro” and “Mara des bois”). The cropping system, irrigation system, and type of fertilizers applied differ from one strawberry farm to another. Biofertilizers (such as mycorrhizal), inorganic and organic fertilizers are actually used to improve production. The potential annual production of strawberries from January 2021 to February 2022, estimated based on the survey data, was 21.216 tons for all growers. Among these eight production farms, the Lolodorf BIO Farm presents 6000 kg (six tons) of strawberries and 100,000 stolons (seedlings) produced, from seven varieties of Fragaria spp. cultivated, with 6 varieties which are hybrids variety Fragaria x ananassa (“Amiga”, “Amine”, “Chandler”, “Gariguette”, “Madame Moutot”, and “Ruby gem”), and one which is a hybrid of Fragaria vesca (“Mara des bois”). Certain diseases were also observed and recorded depending on the growing areas.展开更多
Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales site...Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.展开更多
Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the ev...Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the evolution also have conserved “backbone sequences”, which reveal the marks of their origin and evolution, and these “backbone sequences”are just the basis of their elementary living abilities and common biological properties. Shigella is very closely related to E. coli in the origin and evolution, and may turn out to belong to the same genus. In this study, a microarray containing E. coli K-12 whole genome and Sf301 specific ORFs is used to investigate the genomic components of four Shigella strains. The results indicate that 16%-22% K-12 ORFs sequences are not detected in the genome of Shigella strains while the genome of Shigella contains at least 2800 conserved ORFs, which compose the common “backbone sequences”.Advanced analysis indicated that the “backbone sequences”are the essential components in maintaining the normal physiological activities of intestinal bacteria. Furthermore,only 20% Sf301-specific ORFs exist in other strains simultaneously, which demonstrate the great genome heterogeneity and the genetic diversity among the strains.展开更多
伪距单点定位(Pseudo-range Single Point Positioning,SPP)应用较早且广泛。随着GNSS相关技术的不断进步,伪距观测值与广播星历的精度也在不断提高,多GNSS系统还带来了更多的伪距观测值,SPP依然值得关注。RTKLIB作为一款广为接受的多功...伪距单点定位(Pseudo-range Single Point Positioning,SPP)应用较早且广泛。随着GNSS相关技术的不断进步,伪距观测值与广播星历的精度也在不断提高,多GNSS系统还带来了更多的伪距观测值,SPP依然值得关注。RTKLIB作为一款广为接受的多功能GNSS数据处理开源软件,是实现二次开发的良好平台,为此,本文对新版本RTKLIB(b34)SPP数据处理进行了解析,给出了其处理流程,分析了其平差求解、结果检验、异常检测的原理,指出了其优缺点,为今后借鉴或改进提供了参考。展开更多
基金supported by the Research Fund from Ministry of Health of the People’s Republic of China, WKJ2007‐2‐024
文摘Objective To investigate the characteristic of integrons and the relationship between integrons and antimicrobial resistance in Shigella spp. Methods Ninety Shigella strains (83 S. flexneri and 7 S. sonnei) were isolated from the stools of patients in China. Susceptibility to 8 antimicrobials was tested for all isolated strains. PCR, RFLP and sequencing analysis of integrons were applied to all of them. Results High prevalence of multi‐drug resistance (95.6%) was identified. Of the isolates 79 (87.8%) carried integrase genes of class 1 integron (3.3%), class 2 integron (10.0%) or both (74.4%). No intI3 was detected in the tested isolates. The prevalence of intI2 was significantly higher in isolates with multi‐drug resistance to at least 3 antibiotics than that in isolates with resistance to 2 and less antibiotics (P0.05). Gene cassettes dfrA17‐aadA5, dfrA12‐orfF‐aadA2 of class 1 integron and dfrA1‐sat1‐aadA1 of class 2 integron were identified. Conclusion The class 2 integron may play a role in the emergence of multi‐drug resistance in Shigella spp.
文摘Introduction: Salmonella and Shigella are gram-negative bacilli that are resistant to most antibiotics and play an important role in an etiology of diarrhea disease. The aim of the study was to determine the prevalence of Salmonella spp and Shigella spp isolated from stool and blood samples in the city of N’Djamena. Materials and Method: This was a prospective study conducted in the four district hospitals of N’Djamena from 14 July 2022 to 31 December 2022. A questionnaire form was drawn up to collect the information sent to the study patients. The samples were analyzed at the CHU de la Mère et de l’Enfant, Labo-Redes laboratory according to their protocols and the standard of the antibiogram committee of the French microbiology society. Results: Of the 803 biological samples analyzed, 39 were positive for Salmonella spp and Shigella spp, including 15 for Salmonella and 24 for Shigella, giving an overall prevalence rate of 4.85%. Borehole water, uncooked food and lack of access to a latrine constitute a risk of being infected by Salmonella spp and Shigella spp species. Of the 8 antibiotics tested, Salmonella spp and Shigella spp strains showed good sensitivity to nalidixic acid (100% for Salmonella and 90 for Shigella) and to ciprofloxacin (90.9% for Salmonella and 75% for Shigella). Resistance to ampicillin was found in 81.81% of Salmonella species and 78.57% of Shigella species, as was resistance to chloramphenicol (81.81% of Salmonella species and 67.85% of Shigella species). Similarly, cleanliness of the service and equipment is an essential factor in preventing Salmonella and Shigella infections.
文摘Jute mallow is a nutritious leafy vegetable. The leaves are rich in proteins, vitamins and essential amino acids. Molecular characterization of Jute mallow with focus on improvement of leaf yield is scarcely reported. In the present study, inter sequence simple repeats (ISSR) molecular markers were employed to assess genetic diversity and relationships of 83 accessions of Jute mallow from different parts of Africa and Asia conserved at the World Vegetable Center East and Southern Africa. A total of 89 bands were amplified by 8 ISSR primers. Number of polymorphic bands per primer ranged from 2 to 6 with an average of 2.75 bands per primer. Polymorphic information content (PIC) values ranged from 0.390 to 0.760 with average of 0.53. Average Nei’s gene diversity (h) and Shannon’s information index (I) were 0.335 and 0.494 respectively. The highest pairwise genetic distance was 0.431 observed in a population from East Africa accessions. PC1 and PC2 axis explained 21.69% and 11.66% of the total variation respectively. UPGMA cluster analysis grouped the accessions into six main clusters at genetic similarity coefficient of 0.53 as standard value for classification. These results have important implications for jute mallow breeding and conservation.
文摘Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms of Fragaria spp. from January 2021 to February 2022. The plant was introduced in Cameroon in 2018. There are 13 varieties of Fragaria spp. currently cultivated. Among these 13 varieties, eleven are hybrids of Fragaria x ananassa (“Amiga”, “Amine”, “Camarosa”, “Chandler”, “Charlotte”, “Elsanta”, “Gariguette”, “Madame Moutot”, “Ostara”, “Ruby gem” and “San Andreas”), and two of the hybrids of Fragaria vesca (“Maestro” and “Mara des bois”). The cropping system, irrigation system, and type of fertilizers applied differ from one strawberry farm to another. Biofertilizers (such as mycorrhizal), inorganic and organic fertilizers are actually used to improve production. The potential annual production of strawberries from January 2021 to February 2022, estimated based on the survey data, was 21.216 tons for all growers. Among these eight production farms, the Lolodorf BIO Farm presents 6000 kg (six tons) of strawberries and 100,000 stolons (seedlings) produced, from seven varieties of Fragaria spp. cultivated, with 6 varieties which are hybrids variety Fragaria x ananassa (“Amiga”, “Amine”, “Chandler”, “Gariguette”, “Madame Moutot”, and “Ruby gem”), and one which is a hybrid of Fragaria vesca (“Mara des bois”). Certain diseases were also observed and recorded depending on the growing areas.
文摘Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.
文摘Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the evolution also have conserved “backbone sequences”, which reveal the marks of their origin and evolution, and these “backbone sequences”are just the basis of their elementary living abilities and common biological properties. Shigella is very closely related to E. coli in the origin and evolution, and may turn out to belong to the same genus. In this study, a microarray containing E. coli K-12 whole genome and Sf301 specific ORFs is used to investigate the genomic components of four Shigella strains. The results indicate that 16%-22% K-12 ORFs sequences are not detected in the genome of Shigella strains while the genome of Shigella contains at least 2800 conserved ORFs, which compose the common “backbone sequences”.Advanced analysis indicated that the “backbone sequences”are the essential components in maintaining the normal physiological activities of intestinal bacteria. Furthermore,only 20% Sf301-specific ORFs exist in other strains simultaneously, which demonstrate the great genome heterogeneity and the genetic diversity among the strains.
文摘伪距单点定位(Pseudo-range Single Point Positioning,SPP)应用较早且广泛。随着GNSS相关技术的不断进步,伪距观测值与广播星历的精度也在不断提高,多GNSS系统还带来了更多的伪距观测值,SPP依然值得关注。RTKLIB作为一款广为接受的多功能GNSS数据处理开源软件,是实现二次开发的良好平台,为此,本文对新版本RTKLIB(b34)SPP数据处理进行了解析,给出了其处理流程,分析了其平差求解、结果检验、异常检测的原理,指出了其优缺点,为今后借鉴或改进提供了参考。