Evidence map›Paper›PMID 40924746›Full record

ArticlePLoS neglected tropical diseases2025

Diversity of Salmonella enterica isolates from urban river and sewage water in Blantyre, Malawi.

Jonathan Rigby, Catherine N Wilson, Allan Zuza, Yohane Diness, Charity Mkwanda, Katalina Tonthola, Oscar Kanjerwa, Chifundo Salifu, Oliver Pearse, Chisomo Msefula and 7 more

Abstract read
In one paragraph

Article in PLoS neglected tropical diseases, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

17 authors.

Jonathan RigbyDepartment of Clinical Science, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.ORCID 0000-0001-5143-0981
Catherine N WilsonMalawi-Liverpool-Wellcome Programme, Kamuzu University of Health Sciences, Blantyre, Malawi.
Allan ZuzaMalawi-Liverpool-Wellcome Programme, Kamuzu University of Health Sciences, Blantyre, Malawi.
Yohane DinessMalawi-Liverpool-Wellcome Programme, Kamuzu University of Health Sciences, Blantyre, Malawi.
Charity MkwandaMalawi-Liverpool-Wellcome Programme, Kamuzu University of Health Sciences, Blantyre, Malawi.
Katalina TontholaMalawi-Liverpool-Wellcome Programme, Kamuzu University of Health Sciences, Blantyre, Malawi.
Oscar KanjerwaMalawi-Liverpool-Wellcome Programme, Kamuzu University of Health Sciences, Blantyre, Malawi.
Chifundo SalifuMalawi-Liverpool-Wellcome Programme, Kamuzu University of Health Sciences, Blantyre, Malawi.
Oliver PearseDepartment of Clinical Science, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
Chisomo MsefulaKamuzu University of Health Sciences, Blantyre, Malawi.
Blanca M Perez-SepulvedaInstitute of Infection, Veterinary and Ecological Sciences University of Liverpool, Liverpool, United Kingdom.
Jay C D HintonInstitute of Infection, Veterinary and Ecological Sciences University of Liverpool, Liverpool, United Kingdom.
Satheesh NairUnited Kingdom Health Security Agency, Colindale, London, United Kingdom.
Nicola ElvissUnited Kingdom Health Security Agency, Colindale, London, United Kingdom.
Mathew A BealeParasites and Microbes Programme, Wellcome Sanger Institute, Hinxton, Cambridgeshire, United Kingdom.
Patrick MusichaMalawi-Liverpool-Wellcome Programme, Kamuzu University of Health Sciences, Blantyre, Malawi.
Nicholas A FeaseyDepartment of Clinical Science, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.

Funding

Gates Foundation INV-008749Wellcome Trust
6 · The paper itself

Abstract

backgroundSalmonella enterica encompasses over 2,600 serovars, including several commonly associated with severe infection in humans. Salmonella is a major cause of sepsis in Africa; however, diagnosis requires clinical microbiology facilities. Environmental surveillance has the potential to play a role in Salmonella surveillance.

methodsWe undertook water-based environmental surveillance in Blantyre, Malawi, from 2018-2020, taking samples from rivers (87.9%), a sewage plant (8.85%) and other water sources (3.24%), isolating and storing 1,042 non-typhoidal Salmonella (NTS) isolates in this period. Of these, 341 NTS isolates were whole genome sequenced, genome quality was checked, duplicate genomes from any given sample were removed and core genome phylogeny was reconstructed. AMRFinder, PathogenWatch and SISTR were used to further investigate serovar, sequence type and antimicrobial resistance determinants.

resultsAfter quality checks, and removal of duplicate genomes, 270 NTS genomes remained for further analysis. Multiple Salmonella serovars associated with human infection were detected, of which S. Typhimurium (55/270 isolates) was the most common, including 44 of Sequence Type (ST) 313, a serovar commonly associated with severe invasive disease (iNTS). Six lineage 2 ST313 genomes possessed AMR genes predicting multidrug resistance (MDR), while 29 lineage 3 isolates contained no AMR predictive genes. PCR based detection of staG has been proposed as a diagnostic marker of S. Typhi; however, all eight genomes that contained staG identified as Salmonella enterica serovar Orion, raising concerns about the specificity of this marker as a monoplex for environmental surveillance of S. Typhi. DISCUSSION: The study identified diverse Salmonella serovars in the environment, including those reported to cause invasive disease, emphasizing the complex but potentially valuable contribution of implementing environmental surveillance for Salmonella in high burden areas lacking diagnostic microbiology capacity.

Indexed as

RiversSalmonella entericaSewageWater MicrobiologyAnti-Bacterial AgentsGenome, BacterialHumansMalawiPhylogenySalmonella InfectionsSerogroupWhole Genome SequencingAnti-Bacterial AgentsSewage

Identifiers

PMID40924746
PMCPMC12431665

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.