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Papers by Elizabeth Gyamfi

Research paper thumbnail of Variable Number Tandem Repeat Profiling of Mycobacterium ulcerans Reveals New Genotypes in Buruli Ulcer Endemic Communities in Ghana and Côte d’Ivoire

Frontiers in Microbiology

Buruli ulcer (BU), a necrotic skin disease caused by Mycobacterium ulcerans, is mainly prevalent ... more Buruli ulcer (BU), a necrotic skin disease caused by Mycobacterium ulcerans, is mainly prevalent in West Africa, but cases have also been reported in other tropical parts of the world. It is the second most common mycobacterial disease after tuberculosis in Ghana and Côte d’Ivoire. Heterogeneity among M. ulcerans from different geographical locations has not been clearly elucidated, and some studies seem to suggest genetic differences between M. ulcerans in humans and in the environment. This study aimed at identifying genetic differences among M. ulcerans strains between two BU endemic countries: Ghana and Côte d’Ivoire. Clinical samples consisting of swabs, fine needle aspirates, and tissue biopsies of suspected BU lesions and environmental samples (e.g., water, biofilms from plants, soil, and detrital material) were analyzed. BU cases were confirmed via acid fast staining and PCR targeting the 16S rRNA, IS2404, IS2606, and ER domain genes present on M. ulcerans. Heterogeneity amo...

Research paper thumbnail of Additional file 2: of Investigating the virulence genes and antibiotic susceptibility patterns of Vibrio cholerae O1 in environmental and clinical isolates in Accra, Ghana

Effect of physicochemical parameters on occurrence of V. cholerae O1 in the sample area. (A-Total... more Effect of physicochemical parameters on occurrence of V. cholerae O1 in the sample area. (A-Total dissolved solids, B-Temperature, C-Conductivity D-pH, E- Salinity). * = p

Research paper thumbnail of Additional file 1: of Investigating the virulence genes and antibiotic susceptibility patterns of Vibrio cholerae O1 in environmental and clinical isolates in Accra, Ghana

General physicochemical parameters (pH, Temperature, TDS and Conductivity) of water sources (RTF ... more General physicochemical parameters (pH, Temperature, TDS and Conductivity) of water sources (RTF 80 kb)

Research paper thumbnail of Microbiology of secondary infections in Buruli ulcer lesions; implications for therapeutic interventions

BMC Microbiology, 2021

Background Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans and is the second... more Background Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans and is the second most common mycobacterial disease after tuberculosis in Ghana and Côte d’Ivoire. M. ulcerans produces mycolactone, an immunosuppressant macrolide toxin, responsible for the characteristic painless nature of the infection. Secondary infection of ulcers before, during and after treatment has been associated with delayed wound healing and resistance to streptomycin and rifampicin. However, not much is known of the bacteria causing these infections as well as antimicrobial drugs for treating the secondary microorganism. This study sought to identify secondary microbial infections in BU lesions and to determine their levels of antibiotic resistance due to the prolonged antibiotic therapy required for Buruli ulcer. Results Swabs from fifty-one suspected BU cases were sampled in the Amansie Central District from St. Peters Hospital (Jacobu) and through an active case surveillance. Forty of the...

Research paper thumbnail of Investigating the virulence genes and antibiotic susceptibility patterns of Vibrio cholerae O1 in environmental and clinical isolates in Accra, Ghana

BMC Infectious Diseases, 2019

Background: Cholera has been endemic in Ghana since its detection in 1970. It has been shown that... more Background: Cholera has been endemic in Ghana since its detection in 1970. It has been shown that long-term survival of the bacteria may be attained in aquatic environments. Consequently, cholera outbreaks may be triggered predominantly in densely populated urban areas. We investigated clinical and environmental isolates of Vibrio cholerae O1 in Accra to determine their virulence genes, antibiotic susceptibility patterns and environmental factors maintaining their persistence in the environment. Methods: Water samples from various sources were analyzed for the presence of V. cholerae O1 using culture methods. Forty clinical isolates from a previous cholera outbreak were included in the study for comparison. Antibiotic susceptibility patterns of the bacteria were determined by disc diffusion. Virulence genes were identified by analyzing genes for ctx, tcpA (tcpA El Tor tcpA Cl), zot, ompW, rbfO1 and attRS using PCR. Physicochemical characteristics of water were investigated using standard methods. One-way ANOVA and student t-test were employed to analyze the relationship between physicochemical factors and the occurrence of V. cholerae O1. Results: Eleven V. cholerae O1 strains were successfully isolated from streams, storage tanks and wells during the study period. All isolates were resistant to one or more of the eight antibiotics used. Multidrug resistance was observed in over 97% of the isolates. All isolates had genes for at least one virulence factor. Vibrio cholerae toxin gene was detected in 82.4% of the isolates. Approximately 81.8% of the isolates were positive for tcpA El Tor gene, but also harbored the tcpA cl gene. Isolates were grouped into thirteen genotypes based on the genes analyzed. High temperature, salinity, total dissolved solids and conductivity was found to significantly correlate positively with isolation of V. cholerae O1. V. cholerae serotype Ogawa biotype El tor is the main biotype circulating in Ghana with the emergence of a hybrid strain. Conclusions: Multidrug resistant V. cholerae O1 with different genotypes and pathogenicity are present in water sources and co-exist with non O1/O139 in the study area.

Research paper thumbnail of Variable Number Tandem Repeat Profiling of Mycobacterium ulcerans Reveals New Genotypes in Buruli Ulcer Endemic Communities in Ghana and Côte d’Ivoire

Frontiers in Microbiology

Buruli ulcer (BU), a necrotic skin disease caused by Mycobacterium ulcerans, is mainly prevalent ... more Buruli ulcer (BU), a necrotic skin disease caused by Mycobacterium ulcerans, is mainly prevalent in West Africa, but cases have also been reported in other tropical parts of the world. It is the second most common mycobacterial disease after tuberculosis in Ghana and Côte d’Ivoire. Heterogeneity among M. ulcerans from different geographical locations has not been clearly elucidated, and some studies seem to suggest genetic differences between M. ulcerans in humans and in the environment. This study aimed at identifying genetic differences among M. ulcerans strains between two BU endemic countries: Ghana and Côte d’Ivoire. Clinical samples consisting of swabs, fine needle aspirates, and tissue biopsies of suspected BU lesions and environmental samples (e.g., water, biofilms from plants, soil, and detrital material) were analyzed. BU cases were confirmed via acid fast staining and PCR targeting the 16S rRNA, IS2404, IS2606, and ER domain genes present on M. ulcerans. Heterogeneity amo...

Research paper thumbnail of Additional file 2: of Investigating the virulence genes and antibiotic susceptibility patterns of Vibrio cholerae O1 in environmental and clinical isolates in Accra, Ghana

Effect of physicochemical parameters on occurrence of V. cholerae O1 in the sample area. (A-Total... more Effect of physicochemical parameters on occurrence of V. cholerae O1 in the sample area. (A-Total dissolved solids, B-Temperature, C-Conductivity D-pH, E- Salinity). * = p

Research paper thumbnail of Additional file 1: of Investigating the virulence genes and antibiotic susceptibility patterns of Vibrio cholerae O1 in environmental and clinical isolates in Accra, Ghana

General physicochemical parameters (pH, Temperature, TDS and Conductivity) of water sources (RTF ... more General physicochemical parameters (pH, Temperature, TDS and Conductivity) of water sources (RTF 80 kb)

Research paper thumbnail of Microbiology of secondary infections in Buruli ulcer lesions; implications for therapeutic interventions

BMC Microbiology, 2021

Background Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans and is the second... more Background Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans and is the second most common mycobacterial disease after tuberculosis in Ghana and Côte d’Ivoire. M. ulcerans produces mycolactone, an immunosuppressant macrolide toxin, responsible for the characteristic painless nature of the infection. Secondary infection of ulcers before, during and after treatment has been associated with delayed wound healing and resistance to streptomycin and rifampicin. However, not much is known of the bacteria causing these infections as well as antimicrobial drugs for treating the secondary microorganism. This study sought to identify secondary microbial infections in BU lesions and to determine their levels of antibiotic resistance due to the prolonged antibiotic therapy required for Buruli ulcer. Results Swabs from fifty-one suspected BU cases were sampled in the Amansie Central District from St. Peters Hospital (Jacobu) and through an active case surveillance. Forty of the...

Research paper thumbnail of Investigating the virulence genes and antibiotic susceptibility patterns of Vibrio cholerae O1 in environmental and clinical isolates in Accra, Ghana

BMC Infectious Diseases, 2019

Background: Cholera has been endemic in Ghana since its detection in 1970. It has been shown that... more Background: Cholera has been endemic in Ghana since its detection in 1970. It has been shown that long-term survival of the bacteria may be attained in aquatic environments. Consequently, cholera outbreaks may be triggered predominantly in densely populated urban areas. We investigated clinical and environmental isolates of Vibrio cholerae O1 in Accra to determine their virulence genes, antibiotic susceptibility patterns and environmental factors maintaining their persistence in the environment. Methods: Water samples from various sources were analyzed for the presence of V. cholerae O1 using culture methods. Forty clinical isolates from a previous cholera outbreak were included in the study for comparison. Antibiotic susceptibility patterns of the bacteria were determined by disc diffusion. Virulence genes were identified by analyzing genes for ctx, tcpA (tcpA El Tor tcpA Cl), zot, ompW, rbfO1 and attRS using PCR. Physicochemical characteristics of water were investigated using standard methods. One-way ANOVA and student t-test were employed to analyze the relationship between physicochemical factors and the occurrence of V. cholerae O1. Results: Eleven V. cholerae O1 strains were successfully isolated from streams, storage tanks and wells during the study period. All isolates were resistant to one or more of the eight antibiotics used. Multidrug resistance was observed in over 97% of the isolates. All isolates had genes for at least one virulence factor. Vibrio cholerae toxin gene was detected in 82.4% of the isolates. Approximately 81.8% of the isolates were positive for tcpA El Tor gene, but also harbored the tcpA cl gene. Isolates were grouped into thirteen genotypes based on the genes analyzed. High temperature, salinity, total dissolved solids and conductivity was found to significantly correlate positively with isolation of V. cholerae O1. V. cholerae serotype Ogawa biotype El tor is the main biotype circulating in Ghana with the emergence of a hybrid strain. Conclusions: Multidrug resistant V. cholerae O1 with different genotypes and pathogenicity are present in water sources and co-exist with non O1/O139 in the study area.