Health Risk Assessments of Selected Trace Elements and Factors Associated with Their Levels in Human Breast Milk from Pretoria, South Africa.
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ABSTRACT:
SUBMITTER: Olowoyo JO
PROVIDER: S-EPMC8464967 | biostudies-literature |
REPOSITORIES: biostudies-literature
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2019-10-17 | GSE138949 | GEO
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Project description:Antibiotic-resistant Klebsiella pneumoniae is increasingly being implicated in invasive infections worldwide with high mortalities. Forty-two multidrug resistant (MDR) K. pneumoniae isolates were collected over a 4-month period. Antimicrobial susceptibility was determined using Microscan. The evolutionary epidemiology, resistome, virulome and mobilome of the isolates were characterised using whole-genome sequencing and bioinformatics analysis. All isolates contained the blaCTX-M gene, whilst 41/42(97%) contained blaTEM, 36/42(86%) contained blaOXA and 35/42(83%) harboured blaSHV genes. Other resistance genes found included blaLEN, aac(6')-lb-cr, qnrA, qnrB, qnrS, oqxAB, aad, aph, dfr, sul1, sul2, fosA, and cat genes. Fluoroquinolone and colistin resistance-conferring mutations in parC, gyrAB, pmrAB, phoPQ and kpnEF were identified. The blaLEN gene, rarely described worldwide, was identified in four isolates. The isolates comprised diverse sequence types, the most common being ST152 in 7/42(17%) isolates; clone-specific O and K capsule types were identified. Diverse virulence genes that were not clone-specific were identified in all but one isolate. IncF, IncH and IncI plasmid replicons and two novel integrons were present. The blaCTX-M-15 and blaTEM-1 genes were bracketed by Tn3 transposons, ISEc9, a resolvase and IS91 insertion sequence. There were 20 gene cassettes in 14 different cassette arrays, with the dfrA and aadA gene cassettes being the most frequent. Phylogenetic analysis demonstrated that the isolates were evolutionarily associated with strains from both South Africa and abroad. These findings depict the rich resistome, mobilome and virulome repertoire in clinical K. pneumoniae strains, which are mainly transmitted by clonal, multiclonal and horizontal means in South Africa.
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Project description:BackgroundSouth Africa has 6.4 million adults over the age of 15 living with HIV. Gender inequality issues continue to drive the HIV epidemic in South Africa, where Black African women bear the greatest HIV burden. Limited access to services; little capacity to negotiate sex and condom use; and other legal, social, and economic inequities make women highly vulnerable to HIV infection. Behavioral interventions have been shown to decrease risk behaviors, but they have been less successful in reducing HIV incidence. Conversely, biomedical prevention strategies have proven to be successful in reducing HIV incidence, but require behavioral interventions to increase uptake and adherence. Consequently, there is a need for integrated approaches that combine biomedical and behavioral interventions. Effective combination prevention efforts should comprise biomedical, behavioral, and structural programming proven in randomized trials that focuses on the driving forces and key populations at higher risk of HIV infection and transmission.Methods/designThis prospective, geographically clustered randomized field experiment is enrolling participants into two arms: a control arm that receives standard HIV testing and referral for treatment; and an intervention arm that receives an evidence-based, woman-focused behavioral intervention that emphasizes risk reduction and retention, the Women's Health CoOp. We divided the city of Pretoria into 14 mutually exclusive geographic zones and randomized these zones into either the control arm or the intervention arm. Outreach workers are recruiting drug-using women from each zone. At baseline, eligible participants complete a questionnaire and biological testing for HIV, recent drug use, and pregnancy. Follow-up interviews are completed at 6 and 12 months.DiscussionThe biobehavioral intervention in this study merges an efficacious behavioral HIV prevention intervention for women with biomedical prevention through HIV treatment as prevention using a Seek, Test, Treat and Retain strategy. This combination biobehavioral intervention is designed to (1) improve the quality of life and reduce HIV infectiousness among women who are HIV positive, and (2) reduce HIV risk behaviors among women regardless of their HIV status. If efficacious, this intervention could help control the HIV epidemic in South Africa.Trial registrationTrial registration no: NCT01497405.
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Project description:Antibiotic-resistant Escherichia coli is a common occurrence in food, clinical, community and environmental settings worldwide. The resistome, mobilome, virulome and phylogenomics of 20 multidrug resistant (MDR) clinical E. coli isolates collected in 2013 from Pretoria, South Africa, were characterised. The isolates were all extended-spectrum β-lactamase producers, harbouring CTX-M (n = 16; 80%), TEM-1B (n = 10; 50%) and OXA (n = 12, 60%) β-lactamases alongside genes mediating resistance to fluoroquinolones, aminoglycosides, tetracyclines etc. Most resistance determinants were found on contigs containing IncF plasmid replicons and bracketed by composite transposons (Tn3), diverse ISs and class 1 integrons (In13, In54, In369, and In467). Gene cassettes such as blaOXA, dfrA5-psp-aadA2-cmlA1a-aadA1-qac and estX3-psp-aadA2-cmlA1a-aadA1a-qac were encompassed by Tn3 and ISs; several isolates had same or highly similar genomic antibiotic resistance islands. ST131 (n = 10), ST617 (n = 2) and singletons of ST10, ST73, ST95, ST410, ST648, ST665, ST744 and ST998 clones were phylogenetically related to clinical (human and animal) strains from Egypt, Kenya, Niger, Nigeria, Tanzania, and UK. A rich repertoire of virulence genes, including iss, gad and iha were identified. MDR E. coli harbouring chromosomal and plasmid-borne resistance genes in same and multiple clones exist in South Africa, which is very worrying for clinical epidemiology and infectious diseases management.
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