scholarly journals Genomic diversity and antimicrobial resistance among non-typhoidal Salmonella associated with human disease in The Gambia

2020 ◽  
Author(s):  
Saffiatou Darboe ◽  
Richard S. Bradbury ◽  
Jody Phelan ◽  
Abdoulie Kanteh ◽  
Abdul-Khalie Muhammad ◽  
...  

AbstractNon-typhoidal Salmonella associated with multidrug resistance cause invasive disease in sub-Saharan African. Specific lineages of serovars S. Typhimurium and S. Enteritidis are implicated. We characterised the genomic diversity of 100 clinical Non-typhoidal Salmonella collected from 93 patients in 2001 from the eastern and 2006 to 2018 in the western regions of The Gambia respectively. Phenotypic susceptibility applied Kirby Baur disk diffusion and whole genome sequencing utilized Illumina platforms. The predominant serovars were S. Typhimurium ST19 (31/100) and S. Enteritidis ST11 (18/100) restricted to invasive disease with the notable absence of S. Typhimurium ST313. Phylogenetic analysis performed in the context of 495 African strains from the European Nucleotide Archive confirmed the presence of the S. Enteritidis virulent epidemic invasive multidrug resistant West African clade. Multidrug resistance including chloramphenicol and azithromycin has emerged among the West African S. Enteritidis clade 7/9 (78%) with potential for spread, thus having important implications for patient management warranting systematic surveillance and epidemiologic investigations to inform control.Data summarySequences are deposited in the NCBI sequence reads archive (SRA) under BioProject ID:PRJEB38968. The genomic assemblies are available for download from the European Nucleotide Archive (ENA): http://www.ebi.ac.uk/ena/data/view/. Accession numbers SAMEA6991082 to SAME6991180

2005 ◽  
Vol 35 (4) ◽  
pp. 450-481 ◽  
Author(s):  
Marloes Janson

AbstractThe proliferation of the Tablīgh Jamā'at, an Islamic missionary movement that strictly observes the fundamentals of the faith, is a manifestation of the recent Islamic resurgence in West Africa. The movement originated in South Asia, but has expanded to Africa. Despite the Jamā'at's great influence on the lives of many West African Muslims, sub-Saharan Africa is a region that has been ignored almost completely in studies of the movement. This article focuses on The Gambia, which appears to be a booming centre of Tablīgh activities in West Africa. On the basis of the conversion stories of a male and a female Tablīgh activist, the central themes in the Gambian branch of the Tablīgh Jamā'at will be explored. These themes result from local factors such as the socio-economic crisis and gender relations. Nevertheless, they also bear similarities with recurrent subjects in other 'fundamentalist' movements throughout the world.


2013 ◽  
Vol 7 (01) ◽  
pp. 001-005 ◽  
Author(s):  
John Wain ◽  
Karen H Keddy ◽  
Rene S Hendriksen ◽  
Salvatore Rubino

The publication of studies using next generation sequencing to analyse large numbers of bacterial isolates from global epidemics is transforming microbiology, epidemiology and public health. The emergence of multidrug resistant Salmonella Typhimurium ST313 is one example. While the epidemiology in Africa appears to be human-to-human spread and the association with invasive disease almost absolute, more needs to be done to exclude the possibility of animal reservoirs and to transfer the ability to track all Salmonella infections to the laboratories in the front line. In this mini-review we summarise what is currently known about non-typhoidal Salmonella in sub-Saharan Africa and discuss some of the issues which remain.


mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Alison E. Mather ◽  
Tu Le Thi Phuong ◽  
Yunfeng Gao ◽  
Simon Clare ◽  
Subhankar Mukhopadhyay ◽  
...  

ABSTRACT Nontyphoidal Salmonella (NTS), particularly Salmonella enterica serovar Typhimurium, is among the leading etiologic agents of bacterial enterocolitis globally and a well-characterized cause of invasive disease (iNTS) in sub-Saharan Africa. In contrast, S. Typhimurium is poorly defined in Southeast Asia, a known hot spot for zoonotic disease with a recently described burden of iNTS disease. Here, we aimed to add insight into the epidemiology and potential impact of zoonotic transfer and antimicrobial resistance (AMR) in S. Typhimurium associated with iNTS and enterocolitis in Vietnam. We performed whole-genome sequencing and phylogenetic reconstruction on 85 human (enterocolitis, carriage, and iNTS) and 113 animal S. Typhimurium isolates isolated in Vietnam. We found limited evidence for the zoonotic transmission of S. Typhimurium. However, we describe a chain of events where a pandemic monophasic variant of S. Typhimurium (serovar I:4,[5],12:i:− sequence type 34 [ST34]) has been introduced into Vietnam, reacquired a phase 2 flagellum, and acquired an IncHI2 multidrug-resistant plasmid. Notably, these novel biphasic ST34 S. Typhimurium variants were significantly associated with iNTS in Vietnamese HIV-infected patients. Our study represents the first characterization of novel iNTS organisms isolated outside sub-Saharan Africa and outlines a new pathway for the emergence of alternative Salmonella variants into susceptible human populations. IMPORTANCE Salmonella Typhimurium is a major diarrheal pathogen and associated with invasive nontyphoid Salmonella (iNTS) disease in vulnerable populations. We present the first characterization of iNTS organisms in Southeast Asia and describe a different evolutionary trajectory from that of organisms causing iNTS in sub-Saharan Africa. In Vietnam, the globally distributed monophasic variant of Salmonella Typhimurium, the serovar I:4,[5],12:i:− ST34 clone, has reacquired a phase 2 flagellum and gained a multidrug-resistant plasmid to become associated with iNTS disease in HIV-infected patients. We document distinct communities of S. Typhimurium and I:4,[5],12:i:− in animals and humans in Vietnam, despite the greater mixing of these host populations here. These data highlight the importance of whole-genome sequencing surveillance in a One Health context in understanding the evolution and spread of resistant bacterial infections.


2020 ◽  
Author(s):  
Se Eun Park ◽  
Duy Thanh Pham ◽  
Gi Deok Pak ◽  
Ursula Panzner ◽  
Ligia Maria Cruz Espinoza ◽  
...  

Background: Invasive nontyphoidal Salmonella (iNTS) is one of the leading causes of bacteraemia in sub-Saharan Africa. Multi-drug resistance (MDR) and further resistance to third generation cephalosporins and fluoroquinolones have emerged in multiple iNTS serotypes. Molecular epidemiological investigations of nontyphoidal Salmonella are needed to better understand the genetic characteristics and transmission dynamics associated with major MDR iNTS serotypes across the continent. Methods: A total of 166 nontyphoidal Salmonella isolates causing invasive disease were collected from a multi-centre study in eight African countries between 2010 and 2014, and whole-genome sequenced to investigate the geographical distribution, antimicrobial genetic determinants and population structure of iNTS serotypes-genotypes. Phylogeographical reconstruction was further conducted in context of the existing genomic framework of iNTS serotypes Typhimurium and Enteritidis. Population-based incidence of MDR-iNTS disease was also estimated. Results: Salmonella enterica subsp. Enterica serotype Typhimurium (S. Typhimurium) sequence-type (ST) 313 and Salmonella enterica subsp. Enterica serotype Enteritidis (S. Enteritidis) ST11 were predominant, and both exhibited high frequencies of MDR. Salmonella enterica subsp. Enterica serotype Dublin (S. Dublin) ST10 emerged in West Africa. Mutations in the gyrA gene were identified in S. Enteritidis and S. Typhimurium in Ghana; and ST313 carrying blaCTX-M-15 was found in Kenya. Inter-country transmission of MDR ST313 lineage II and the West African Clade of MDR ST11 between Ghana and neighbouring countries including Mali, Burkina Faso, and Nigeria were evident. The incidence of MDR-iNTS disease exceeded 100/100,000-person years-of-observation (PYO) in children aged <5 years in several West African countries. Conclusions: Multiple MDR iNTS serotypes-sequence types, predominantly S. Typhimurium ST313 and S. Enteritidis ST11, are co-circulating in sub-Saharan Africa with evidence of transmission between West African countries. The development of safe and effective iNTS vaccines coupled with appropriate antimicrobial stewardship and adequate epidemiological monitoring are essential to limit the impact of these pathogens in Africa.


2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Cheryll M. Sia ◽  
Sarah L. Baines ◽  
Mary Valcanis ◽  
Darren Y. J. Lee ◽  
Anders Gonçalves da Silva ◽  
...  

Non-typhoidal Salmonella (NTS) is the second most common cause of foodborne bacterial gastroenteritis in Australia with antimicrobial resistance (AMR) increasing in recent years. Whole-genome sequencing (WGS) provides opportunities for in silico detection of AMR determinants. The objectives of this study were two-fold: (1) establish the utility of WGS analyses for inferring phenotypic resistance in NTS, and (2) explore clinically relevant genotypic AMR profiles to third generation cephalosporins (3GC) in NTS lineages. The concordance of 2490 NTS isolates with matched WGS and phenotypic susceptibility data against 13 clinically relevant antimicrobials was explored. In silico serovar prediction and typing was performed on assembled reads and interrogated for known AMR determinants. The surrounding genomic context, plasmid determinants and co-occurring AMR patterns were further investigated for multidrug resistant serovars harbouring bla CMY-2, bla CTX-M-55 or bla CTX-M-65. Our data demonstrated a high correlation between WGS and phenotypic susceptibility testing. Phenotypic-genotypic concordance was observed between 2440/2490 (98.0 %) isolates, with overall sensitivity and specificity rates >98 % and positive and negative predictive values >97 %. The most common AMR determinants were bla TEM-1, sul2, tet(A), strA-strB and floR. Phenotypic resistance to cefotaxime and azithromycin was low and observed in 6.2 % (151/2486) and 0.9 % (16/1834) of the isolates, respectively. Several multi-drug resistant NTS lineages were resistant to 3GC due to different genetic mechanisms including bla CMY-2, bla CTX-M-55 or bla CTX-M-65. This study shows WGS can enhance existing AMR surveillance in NTS datasets routinely produced in public health laboratories to identify emerging AMR in NTS. These approaches will be critical for developing capacity to detect emerging public health threats such as resistance to 3GC.


Diversity ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 428
Author(s):  
Martin Stervander ◽  
Bengt Hansson ◽  
Urban Olsson ◽  
Mark F. Hulme ◽  
Ulf Ottosson ◽  
...  

Larks constitute an avian family of exceptional cryptic diversity and striking examples of convergent evolution. Therefore, traditional morphology-based taxonomy has recurrently failed to reflect evolutionary relationships. While taxonomy ideally should integrate morphology, vocalizations, behaviour, ecology, and genetics, this can be challenging for groups that span several continents including areas that are difficult to access. Here, we combine morphometrics and mitochondrial DNA to evaluate the taxonomy of Calandrella larks, with particular focus on the African C. cinerea and the Asian C. acutirostris complexes. We describe a new range-restricted West African taxon, Calandrella cinerea rufipecta ssp. nov. (type locality: Jos, Plateau State, Nigeria), with an isolated relic population 3000 km from its closest relative in the Rift Valley. We performed molecular species delimitation, employing coalescence-based multi-rate Poisson Tree Processes (mPTP) on cytochrome b sequences across 52 currently recognized lark species, including multiple taxa currently treated as subspecies. Three species-level splits were inferred within the genus Calandrella and another 13 across other genera, primarily among fragmented sub-Saharan taxa and taxa distributed from Northwest Africa to Arabia or East Africa. Previously unknown divergences date back as far as to the Miocene, indicating the presence of currently unrecognized species. However, we stress that taxonomic decisions should not be based on single datasets, such as mitochondrial DNA, although analyses of mitochondrial DNA can be a good indicator of taxa in need of further integrative taxonomic assessment.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S195-S195
Author(s):  
Naeemah Z Logan ◽  
Beth E Karp ◽  
Kaitlin A Tagg ◽  
Claire Burns-Lynch ◽  
Jessica Chen ◽  
...  

Abstract Background Multidrug-resistant (MDR) Shigella sonnei infections are a serious public health threat, and outbreaks are common among men who have sex with men (MSM). In February 2020, Australia’s Department of Health notified CDC of extensively drug-resistant (XDR) S. sonnei in 2 Australian residents linked to a cruise that departed from Florida. We describe an international outbreak of XDR S. sonnei and report on trends in MDR among S. sonnei in the United States. Methods Health departments (HDs) submit every 20th Shigella isolate to CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory for susceptibility testing. We defined MDR as decreased susceptibility to azithromycin (MIC ≥32 µg/mL) with resistance to ampicillin, ciprofloxacin, and cotrimoxazole, and XDR as MDR with additional resistance to ceftriaxone. We used PulseNet, the national subtyping network for enteric disease surveillance, to identify US isolates related to the Australian XDR isolates by short-read whole genome sequencing. We screened these isolates for resistance determinants (ResFinder v3.0) and plasmid replicons (PlasmidFinder) and obtained patient histories from HDs. We used long-read sequencing to generate closed plasmid sequences for 2 XDR isolates. Results NARMS tested 2,781 S. sonnei surveillance isolates during 2011–2018; 80 (2.9%) were MDR, including 1 (0.04%) that was XDR. MDR isolates were from men (87%), women (9%), and children (4%). MDR increased from 0% in 2011 to 15.3% in 2018 (Figure). In 2020, we identified XDR isolates from 3 US residents on the same cruise as the Australians. The US residents were 41–42 year-old men; 2 with available information were MSM. The US and Australian isolates were highly related (0–1 alleles). Short-read sequence data from all 3 US isolates mapped to the blaCTX-M-27 harboring IncFII plasmids from the 2 Australian isolates with &gt;99% nucleotide identity. blaCTX-M-27 genes confer ceftriaxone resistance. Increase in Percentage of Shigella sonnei Isolates with Multidrug Resistance* in the United States, 2011–2018† Conclusion MDR S. sonnei is increasing and is most often identified among men. XDR S. sonnei infections are emerging and are resistant to all recommended antibiotics, making them difficult to treat without IV antibiotics. This outbreak illustrates the alarming capacity for XDR S. sonnei to disseminate globally among at-risk populations, such as MSM. Disclosures All Authors: No reported disclosures


Antibiotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 80 ◽  
Author(s):  
Silpak Biswas ◽  
Mohammed Elbediwi ◽  
Guimin Gu ◽  
Min Yue

Colistin is considered to be a ‘last-resort’ antimicrobial for the treatment of multidrug-resistant Gram-negative bacterial infections. Identification of Enterobacteriaceae, carrying the transferable colistin resistance gene mcr-1, has recently provoked a global health concern. This report presents the first detection of a hydrogen sulfide (H2S)-producing Escherichia coli variant isolated from a human in China, with multidrug resistance (MDR) properties, including colistin resistance by the mcr-1 gene, which could have great implications for the treatment of human infections.


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