18 research outputs found
Genetic diversity and risk factors for the transmission of antimicrobial resistance across human, animals and environmental compartments in East Africa: a review.
BACKGROUND
The emergence and spread of antimicrobial resistance (AMR) present a challenge to disease control in East Africa. Resistance to beta-lactams, which are by far the most used antibiotics worldwide and include the penicillins, cephalosporins, monobactams and carbapenems, is reducing options for effective control of both Gram-positive and Gram-negative bacteria. The World Health Organization, Food and Agricultural Organization and the World Organization for Animal Health have all advocated surveillance of AMR using an integrated One Health approach. Regional consortia also have strengthened collaboration to address the AMR problem through surveillance, training and research in a holistic and multisectoral approach. This review paper contains collective information on risk factors for transmission, clinical relevance and diversity of resistance genes relating to extended-spectrum beta-lactamase-producing (ESBL) and carbapenemase-producing Enterobacteriaceae, and Methicillin-resistant Staphylococcus aureus (MRSA) across the human, animal and environmental compartments in East Africa.
MAIN BODY
The review of the AMR literature (years 2001 to 2019) was performed using search engines such as PubMed, Scopus, Science Direct, Google and Web of Science. The search terms included 'antimicrobial resistance and human-animal-environment', 'antimicrobial resistance, risk factors, genetic diversity, and human-animal-environment' combined with respective countries of East Africa. In general, the risk factors identified were associated with the transmission of AMR. The marked genetic diversity due to multiple sequence types among drug-resistant bacteria and their replicon plasmid types sourced from the animal, human and environment were reported. The main ESBL, MRSA and carbapenem related genes/plasmids were the CTX-Ms (45.7%), SCCmec type III (27.3%) and IMP types (23.8%), respectively.
CONCLUSION
The high diversity of the AMR genes suggests there may be multiple sources of resistance bacteria, or the possible exchange of strains or a flow of genes amongst different strains due to transfer by mobile genetic elements. Therefore, there should be harmonized One Health guidelines for the use of antibiotics, as well as regulations governing their importation and sale. Moreover, the trend of ESBLs, MRSA and carbapenem resistant (CAR) carriage rates is dynamic and are on rise over time period, posing a public health concern in East Africa. Collaborative surveillance of AMR in partnership with regional and external institutions using an integrated One Health approach is required for expert knowledge and technology transfer to facilitate information sharing for informed decision-making
Diversity of Staphylococcus aureus Isolates in European Wildlife
Staphylococcus aureus is a well-known colonizer and cause of infection among
animals and it has been described from numerous domestic and wild animal
species. The aim of the present study was to investigate the molecular
epidemiology of S. aureus in a convenience sample of European wildlife and to
review what previously has been observed in the subject field. 124 S. aureus
isolates were collected from wildlife in Germany, Austria and Sweden; they
were characterized by DNA microarray hybridization and, for isolates with
novel hybridization patterns, by multilocus sequence typing (MLST). The
isolates were assigned to 29 clonal complexes and singleton sequence types
(CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88,
CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425,
CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963)
were not described previously. Resistance rates in wildlife strains were
rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were
identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-
associated lineages CC479 and CC705 were not detected in wildlife in the
present study while, in contrast, a third common cattle lineage, CC97, was
found to be common among cervids. No Staphylococcus argenteus or
Staphylococcus schweitzeri-like isolates were found. Systematic studies are
required to monitor the possible transmission of human- and livestock-
associated S. aureus/MRSA to wildlife and vice versa as well as the possible
transmission, by unprotected contact to animals. The prevalence of S.
aureus/MRSA in wildlife as well as its population structures in different
wildlife host species warrants further investigation
Survey of HIV mothers in Botswana: Feeding methods, support, status disclosure and infant testing
A survey of HIV positive mothers in Botswana, Africa, all enrolled in a PMTCT programme, was conducted. A total of 305 mothers from randomly selected sites volunteered and completed the survey related to infant feeding, disclosure of HIV status, infant testing, and support from family and clinic services. The majority of mothers used formula feeding (64%) with their infants and almost half of the mothers indicated that they believed breastfeeding to be unsafe. The majority of mothers reported having disclosed their HIV status to partners and family and felt they had benefited from having done so. Social stigma did not appear to be a significant concern for the mothers in this study. Overall, mothers were very positive concerning the support they received from partners, family, and medical/clinic services. HIV testing was reported for 178 babies with 5 (3%) found to be positive for HIV. A discussion of the findings, along with recommendations for areas needing further study and attention, is provided
Genomic medicine and risk prediction across the disease spectrum
Genomic medicine is based on the knowledge that virtually every medical condition, disease
susceptibility or response to treatment is caused, regulated or influenced by genes. Genetic
testing may therefore add value across the disease spectrum, ranging from single-gene
disorders with a Mendelian inheritance pattern to complex multi-factorial diseases. The critical
factors for genomic risk prediction are to determine: (1) where the genomic footprint of a
particular susceptibility or dysfunction resides within this continuum, and (2) to what extent the
genetic determinants are modified by environmental exposures. Regarding the small subset of
highly penetrant monogenic disorders, a positive family history and early disease onset are
mostly sufficient to determine the appropriateness of genetic testing in the index case and to
inform pre-symptomatic diagnosis in at-risk family members. In more prevalent polygenic noncommunicable
diseases (NCDs), the use of appropriate eligibility criteria is required to ensure a
balance between benefit and risk. An additional screening step may therefore be necessary to
identify individuals most likely to benefit from genetic testing. This need provided the stimulus
for the development of a pathology-supported genetic testing (PSGT) service as a new model
for the translational implementation of genomic medicine in clinical practice. PSGT is linked to
the establishment of a research database proven to be an invaluable resource for the validation
of novel and previously described gene-disease associations replicated in the South African
population for a broad range of NCDs associated with increased cardio-metabolic risk. The
clinical importance of inquiry concerning family history in determining eligibility for
personalized genotyping was supported beyond its current limited role in diagnosing or
screening for monogenic subtypes of NCDs. With the recent introduction of advanced
microarray-based breast cancer subtyping, genetic testing has extended beyond the genome
of the host to also include tumor gene expression profiling for chemotherapy selection. The
decreasing cost of next generation sequencing over recent years, together with improvement
of both laboratory and computational protocols, enables the mapping of rare genetic disorders
and discovery of shared genetic risk factors as novel therapeutic targets across diagnostic
boundaries. This article reviews the challenges, successes, increasing inter-disciplinary
integration and evolving strategies for extending PSGT towards exome and whole genome
sequencing (WGS) within a dynamic framework. Specific points of overlap are highlighte