Carriage of linezolid-resistant enterococci (LRE) among humans and animals in Nigeria: coexistence of the cfr, optrA, and poxtA genes in Enterococcus faecium of animal origin

Objectives: In contrast to increasing reports of the emergence of linezolid-resistant enterococci (LRE) emanating from many countries in Europe, Asia, and North America, data on its status and dissemination from the African continent remain scarce, with the information available limited to countries in North Africa. This study investigated the carriage of LRE and the genetic mechanism of resistance among Enterococcus faecium and Enterococcus faecalis strains recovered from humans and animals in Makurdi, Nigeria. Methods: We conducted a cross-sectional study between June 2020 and July 2021 during which 630 nonduplicate human and animal faecal samples were collected and processed for the recovery of LRE. The genetic mechanisms for resistance were investigated using polymerase chain reaction (PCR) and Sanger sequencing. Results: Linezolid-resistant enterococci were recovered from 5.87% (37/630; 95% CI: 4.17–8.00) of the samples, with the prevalence in animals and humans being 6.22% [(28/450); 95% CI: 4.17–8.87] and 5.00% [(9/180); 95% CI: 2.31–9.28], respectively. All isolates remained susceptible to vancomycin. No known point mutation mediating linezolid resistance was detected in the 23S rRNA and ribosomal protein genes; however, acquisition of one or more potentially transferable genes (cfr, optrA, and poxtA) was observed in 26 of the 37 LRE isolates. Co-existence of all three transferable genes in a single isolate was found in four E. faecium strains of animal origin. Conclusion: This study provides baseline evidence for the emergence and active circulation of LRE driven majorly by the acquisition of the optrA gene in Nigeria. To the best of our knowledge, our study is the first to report a co-carriage of all three transferable linezolid resistance determinants in E. faecium. Active LRE surveillance is urgently required to understand the extent of LRE spread across sub-Saharan Africa and to develop tailored mitigation strategies

Seroprevalence of Influenza A Virus in Dromedaries in North-Western Nigeria

Although influenza A virus is endemic in wild waterfowl, domestic poultry, swine, humans, bats, cetaceans, dogs, and horses, there is a paucity of data on the potential role of camels in zoonotic transmission of the virus. To estimate the seroprevalence of the influenza A virus in camel populations, four local government areas of Nigeria that share an international border with the Niger Republic were selected. Blood samples from 184 one-hump camels (dromedaries) were collected and tested for influenza IgG antigen by ELISA. Each camel’s demographic variable, such as age, gender, location, production system, and usage, was recorded. The overall seroprevalence rate of influenza virus IgG in this study was 10.33% (95%CI: 6.33–15.66%). In the bivariate model, there was no significant difference in gender, age, site location and production system, except for usage. There was a significantly lower seroprevalence rate among camels used for labour (odds ratio (OR) = 0.34, 95% CI: 0.10–0.97) than those used for meat consumption; however, not after adjusting for other variables in the model. Increase surveillance through early detection, prediction, and risk assessment of pathogens in animal reservoirs and environmental contamination as One Health strategies to reduce potential human spillover is recommended. Molecular epidemiology studies could better elucidate the role of camels in the dynamics of disease transmission pathways

Carriage of linezolid-resistant enterococci (LRE) among humans and animals in Nigeria: coexistence of the cfr, optrA, and poxtA genes in Enterococcus faecium of animal origin

ABSTRACT: Objectives: In contrast to increasing reports of the emergence of linezolid-resistant enterococci (LRE) emanating from many countries in Europe, Asia, and North America, data on its status and dissemination from the African continent remain scarce, with the information available limited to countries in North Africa. This study investigated the carriage of LRE and the genetic mechanism of resistance among Enterococcus faecium and Enterococcus faecalis strains recovered from humans and animals in Makurdi, Nigeria. Methods: We conducted a cross-sectional study between June 2020 and July 2021 during which 630 non-duplicate human and animal faecal samples were collected and processed for the recovery of LRE. The genetic mechanisms for resistance were investigated using polymerase chain reaction (PCR) and Sanger sequencing. Results: Linezolid-resistant enterococci were recovered from 5.87% (37/630; 95% CI: 4.17–8.00) of the samples, with the prevalence in animals and humans being 6.22% [(28/450); 95% CI: 4.17–8.87] and 5.00% [(9/180); 95% CI: 2.31–9.28], respectively. All isolates remained susceptible to vancomycin. No known point mutation mediating linezolid resistance was detected in the 23S rRNA and ribosomal protein genes; however, acquisition of one or more potentially transferable genes (cfr, optrA, and poxtA) was observed in 26 of the 37 LRE isolates. Co-existence of all three transferable genes in a single isolate was found in four E. faecium strains of animal origin. Conclusion: This study provides baseline evidence for the emergence and active circulation of LRE driven majorly by the acquisition of the optrA gene in Nigeria. To the best of our knowledge, our study is the first to report a co-carriage of all three transferable linezolid resistance determinants in E. faecium. Active LRE surveillance is urgently required to understand the extent of LRE spread across sub-Saharan Africa and to develop tailored mitigation strategies

Seroprevalence of Influenza A Virus in Dromedaries in North-Western Nigeria

Although influenza A virus is endemic in wild waterfowl, domestic poultry, swine, humans, bats, cetaceans, dogs, and horses, there is a paucity of data on the potential role of camels in zoonotic transmission of the virus. To estimate the seroprevalence of the influenza A virus in camel populations, four local government areas of Nigeria that share an international border with the Niger Republic were selected. Blood samples from 184 one-hump camels (dromedaries) were collected and tested for influenza IgG antigen by ELISA. Each camel’s demographic variable, such as age, gender, location, production system, and usage, was recorded. The overall seroprevalence rate of influenza virus IgG in this study was 10.33% (95%CI: 6.33–15.66%). In the bivariate model, there was no significant difference in gender, age, site location and production system, except for usage. There was a significantly lower seroprevalence rate among camels used for labour (odds ratio (OR) = 0.34, 95% CI: 0.10–0.97) than those used for meat consumption; however, not after adjusting for other variables in the model. Increase surveillance through early detection, prediction, and risk assessment of pathogens in animal reservoirs and environmental contamination as One Health strategies to reduce potential human spillover is recommended. Molecular epidemiology studies could better elucidate the role of camels in the dynamics of disease transmission pathways

Seroprevalence of Influenza A Virus in Dromedaries in North-Western Nigeria

Although influenza A virus is endemic in wild waterfowl, domestic poultry, swine, humans, bats, cetaceans, dogs, and horses, there is a paucity of data on the potential role of camels in zoonotic transmission of the virus. To estimate the seroprevalence of the influenza A virus in camel populations, four local government areas of Nigeria that share an international border with the Niger Republic were selected. Blood samples from 184 one-hump camels (dromedaries) were collected and tested for influenza IgG antigen by ELISA. Each camel’s demographic variable, such as age, gender, location, production system, and usage, was recorded. The overall seroprevalence rate of influenza virus IgG in this study was 10.33% (95%CI: 6.33–15.66%). In the bivariate model, there was no significant difference in gender, age, site location and production system, except for usage. There was a significantly lower seroprevalence rate among camels used for labour (odds ratio (OR) = 0.34, 95% CI: 0.10–0.97) than those used for meat consumption; however, not after adjusting for other variables in the model. Increase surveillance through early detection, prediction, and risk assessment of pathogens in animal reservoirs and environmental contamination as One Health strategies to reduce potential human spillover is recommended. Molecular epidemiology studies could better elucidate the role of camels in the dynamics of disease transmission pathways

Concurrent resistance to carbapenem and colistin among enterobacteriaceae recovered from human and animal sources in Nigeria is associated with multiple genetic mechanisms

Resistance to last resort drugs such as carbapenem and colistin is a serious global health threat. This study investigated carbapenem and colistin resistance in 583 non-duplicate Enterobacteriaceae isolates utilizing phenotypic methods and whole genome sequencing (WGS). Of the 583 isolates recovered from humans, animals and the environment in Nigeria, 18.9% (110/583) were resistant to at least one carbapenem (meropenem, ertapenem, and imipenem) and 9.1% (53/583) exhibited concurrent carbapenem-colistin resistance. The minimum inhibitory concentrations of carbapenem and colistin were 2-32 mu g/mL and 8 to >64 mu g/mL, respectively. No carbapenem resistant isolates produced carbapenemase nor harbored any known carbapenemase producing genes. WGS supported that concurrent carbapenem-colistin resistance was mediated by novel and previously described alterations in chromosomal efflux regulatory genes, particularly mgrB (M1V) ompC (M1_V24del) ompK37 (I70M, I128M) ramR (M1V), and marR (M1V). In addition, alterations/mutations were detected in the etpA, arnT, ccrB, pmrB in colistin resistant bacteria and ompK36 in carbapenem resistant bacteria. The bacterial isolates were distributed into 37 sequence types and characterized by the presence of internationally recognized high-risk clones. The results indicate that humans and animals in Nigeria may serve as reservoirs and vehicles for the global spread of the isolates. Further studies on antimicrobial resistance in African countries are warranted