Public health aspects of Salmonella enterica in food production

2009 ◽  
pp. 89-116 ◽  
Author(s):  
Tom Humphrey ◽  
Duncan Maskell
Keyword(s):  
Public Health ◽  
Salmonella Enterica ◽  
Food Production

scholarly journals Genomic epidemiology of Salmonella enterica circulating in surface waters used in agriculture and aquaculture in central Mexico

2022 ◽  
Author(s):  
N. E. Ballesteros-Nova ◽  
S. Sánchez ◽  
J. L. Steffani ◽  
L. C. Sierra ◽  
Z. Chen ◽  
...  
Keyword(s):  
Public Health ◽  
North America ◽  
Surface Waters ◽  
Salmonella Enterica ◽  
Food Production ◽  
Current Knowledge ◽  
Comparative Genomic ◽  
Central Mexico ◽  
Clinical Cases

Salmonella enterica (SE) can survive in surface waters (SuWa) and the role of non-host environments in its transmission has acquired increasing relevance. In this study, we conducted comparative genomic analyses of 172 SE isolates collected from SuWa across three months in six states of central Mexico during 2019. SE transmission dynamics were assessed using 87 experimental and 112 public isolates from Mexico collected during 2002-2019. We also studied genetic relatedness between SuWa isolates and human clinical strains collected in North America during 2005-2020. Among experimental isolates, we identified 41 SE serovars and 56 multi-locus sequence types (ST). Predominant serovars were Senftenberg (n=13), Meleagridis, Agona, and Newport (n=12 each), Give (n=10), Anatum (n=8), Adelaide (n=7), and Infantis, Mbandaka, Ohio and Typhimurium (n=6 each). We observed a high genetic diversity in the sample under study, as well as clonal dissemination of strains across distant regions. Some of these strains are epidemiologically important (ST14, ST45, ST118, ST132, ST198, and ST213), and were genotypically close to those involved in clinical cases in North America. Transmission network analysis suggests that SuWa are a relevant source of SE (0.7 source/hub ratio) and contributes to its dissemination as isolates from varied sources and clinical cases have SuWa isolates as common ancestors. Overall, the study shows SuWa act as reservoir of various SE serovars of public health significance. Further research is needed to better understand the mechanisms involved in SuWa contamination by SE, as well as develop interventions to contain its dissemination to food production settings. Study importance Surface waters are heavily used in food production worldwide. Several human pathogens can survive in these waters for long periods and disseminate to food production environments, contaminating our food supply. One of these pathogens is Salmonella enterica , a leading cause of foodborne infections, hospitalizations and deaths in many countries. This research demonstrates the role of surface waters as a vehicle for the transmission of Salmonella along food production chains. It also shows some strains circulating in surface waters are very similar to those implicated in human infections and harbor genes that confer resistance to multiple antibiotics, posing a risk to public health. The study contributes to expand our current knowledge on the ecology and epidemiology of Salmonella in surface waters.

The Affective Politics of Karma among Buddhist Cancer Charities in Vietnam

2020 ◽  
Vol 15 (4) ◽  
pp. 33-62
Author(s):  
Sara Swenson
Keyword(s):  
Public Health ◽  
Global Existence ◽  
Food Production ◽  
Public Health Intervention ◽  
Health Intervention ◽  
Moral Failure ◽  
Cancer Rates ◽  
Charity Work

In this article, I explore how Buddhist charity workers in Vietnam interpret rising cancer rates through understandings of karma. Rather than framing cancer as a primarily physical or medical phenomenon, volunteers state that cancer is a product of collective moral failure. Corruption in public food production is both caused by and perpetuates bad karma, which negatively impacts global existence. Conversely, charity work creates merit, which can improve collective karma and benefit all living beings. I argue that through such interpretations of karma, Buddhist volunteers understand their charity at cancer hospitals as an affective and ethical form of public health intervention.

scholarly journals The microbiological quality of seven large commercial private water supplies in the United Kingdom

2007 ◽  
Vol 5 (4) ◽  
pp. 523-538 ◽  
Author(s):  
D. Kay ◽  
A. P. Wyn-Jones ◽  
C. M. Stapleton ◽  
L. Fewtrell ◽  
M. D. Wyer ◽  
...  
Keyword(s):  
Public Health ◽  
Water Quality ◽  
United Kingdom ◽  
Food Production ◽  
Potable Water ◽  
Microbiological Quality ◽  
Raw Water ◽  
Water Supplies ◽  
The United Kingdom ◽  
The Uk

Some 1% of the UK population derives their potable water from 140,000 private water supplies (PWSs) regulated by Local Authorities. The overwhelming majority of these are very small domestic supplies serving a single property or a small number of properties. Treatment for such supplies is rudimentary or non-existent and their microbiological quality has been shown to be poor in every published study to date. Private water supplies serving commercial enterprises such as hotels, restaurants, food production premises and factories are more frequently treated and subject to closer regulation in the United Kingdom. As a result, it has been assumed that these larger commercial supplies are less likely to experience elevated faecal indicator and pathogen concentrations at the consumer tap which have been observed at small domestic supplies. This paper reports on intensive monitoring at seven commercial private water supplies (six of which were treated) spread throughout the UK serving hotels, holiday parks and food production enterprises. Daily sampling of ‘potable’ water, both at the consumer tap and using large volume filtration for Giardia and Cryptosporidium spp. was conducted over two six week periods in the spring and autumn of 2000. This allowed the effects of short term episodic peaks in faecal indicator and pathogen concentration to be quantified. All the supplies experienced intermittent pathogen presence and only one, a chlorinated deep borehole supply, fully complied with UK water quality regulations during both periods of sampling. Poor microbiological water quality typically followed periods of heavy rainfall. This suggests that the design and installation of such systems should be undertaken only after the likely range of raw water quality has been characterised, which requires a thorough understanding of the effects of flow and seasonality on raw water quality. There is no reason to suspect that the monitored sites are uncharacteristic of other commercial supplies and the results reinforce public health concerns related to domestic supplies. Furthermore, the pattern of contamination is highly episodic, commonly lasting only a few days. Thus, the relatively infrequent regulatory monitoring of such supplies would be unlikely to identify the poor water quality episodes and does not provide the data necessary for public health protection. Although some statistical relationship was found between faecal indicator organisms and the presence of pathogens, the use of FIOs in assessments of regulatory compliance may not always provide a reliable measure of public health risk, i.e. indicator absence does not preclude pathogen presence. The results of this study suggest that a risk assessment system similar to the WHO ‘Water Safety Planning’ approach might offer a more appropriate regulatory paradigm for private water supplies.

Antimicrobial Susceptibility and Virulence Characteristics of Salmonella enterica Typhimurium Isolates from Healthy and Diseased Pigs in Korea

2014 ◽  
Vol 77 (9) ◽  
pp. 1481-1486 ◽  
Author(s):  
MIGMA DORJI TAMANG ◽  
MAMATA GURUNG ◽  
HYANG-MI NAM ◽  
DONG CHAN MOON ◽  
GEUM-CHAN JANG ◽  
...  
Keyword(s):  
Public Health ◽  
Salmonella Typhimurium ◽  
Nalidixic Acid ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Resistance Pattern ◽  
Public Health Concern

This study compared the antimicrobial susceptibility and prevalence of virulence genes in Salmonella enterica Typhimurium isolated from healthy and diseased pigs in Korea. A total of 456 Salmonella Typhimurium isolated from healthy (n = 238) and diseased (n = 218) pigs between 1998 and 2011 were investigated. In total, 93.4% of the Salmonella Typhimurium isolates were resistant to at least one antimicrobial agent tested. The isolates were most often resistant to tetracycline (85.7%), followed by streptomycin (83.6%), nalidixic acid (67.3%), ampicillin (49.3%), chloramphenicol (42.8%), and gentamicin (37.1%). Moreover, multidrug resistance phenotype and resistance to ampicillin, florfenicol, gentamicin, nalidixic acid, neomycin, streptomycin, and tetracycline were significantly higher (P < 0.01) among Salmonella Typhimurium isolates from the diseased pigs compared with those from the healthy pigs. The most common resistance pattern observed in both groups of isolates was streptomycin-tetracycline. Overall, more than 96% of the isolates tested possessed invA, spiA, msgA, sipB, prgH, spaN, tolC, lpfC, sifA, sitC, and sopB virulence genes. The prevalence of orgA, pagC, and iroN were 50.2, 74.1, and 91.0%, respectively, whereas isolates carrying cdtB (1.5%), pefA (7.0%), and spvB (14.9%) were identified much less frequently. Furthermore, the prevalence of invA, lpfC, orgA, pagC, and iroN was significantly higher (P < 0.01) among the isolates from the diseased pigs than in isolates from the healthy pigs. Our results demonstrated that, among diseased pigs, there was significantly higher resistance to some antimicrobials and greater prevalence of some virulence genes than in healthy pigs, indicating the role these factors play in pathogenesis. Multidrug-resistant Salmonella isolates that carry virulence-associated genes are potentially more dangerous and constitute a public health concern. Thus, continuous surveillance of antimicrobial resistance and virulence characteristics in Salmonella is essential.

scholarly journals Enhanced Survival of Salmonella enterica in Vesicles Released by a Soilborne Tetrahymena Species

2005 ◽  
Vol 71 (3) ◽  
pp. 1562-1569 ◽  
Author(s):  
M. T. Brandl ◽  
B. M. Rosenthal ◽  
A. F. Haxo ◽  
S. G. Berk
Keyword(s):  
Public Health ◽  
Salmonella Enterica ◽  
Fluorescent Protein ◽  
Survival Rates ◽  
Human Pathogen ◽  
Initial Ratio ◽  
Calcium Hypochlorite ◽  
Human Macrophages ◽  
Low Concentrations ◽  
Green Fluorescent

ABSTRACT Nondestructive ingestion by soilborne protozoa may enhance the environmental resiliency of important bacterial pathogens and may model how such bacteria evade destruction in human macrophages. Here, the interaction of Salmonella enterica serovar Thompson with a soilborne Tetrahymena sp. isolate was examined using serovar Thompson cells labeled with the green fluorescent protein. The bacteria were mixed in solution with cells of Tetrahymena at several ratios. During incubation with serovar Thompson, Tetrahymena cells released a large number of vesicles containing green fluorescent serovar Thompson cells. In comparison, grazing on Listeria monocytogenes cells resulted in their digestion and thus the infrequent release of this pathogen in vesicles. The number of serovar Thompson cells per vesicle increased significantly as the initial ratio of serovar Thompson to Tetrahymena cells increased from 500:1 to 5,000:1. The density of serovar Thompson was as high as 50 cells per vesicle. Staining with propidium iodide revealed that a significantly higher proportion of serovar Thompson cells remained viable when enclosed in vesicles than when free in solution. Enhanced survival rates were observed in vesicles that were secreted by both starved (F = 28.3, P < 0.001) and unstarved (F = 14.09, P < 0.005) Tetrahymena cells. Sequestration in vesicles also provided greater protection from low concentrations of calcium hypochlorite. Thus, the release of this human pathogen from Tetrahymena cells in high-density clusters enclosed in a membrane may have important implications for public health.

scholarly journals Phylogeography and Resistome Epidemiology of Gram-Negative Bacteria in Africa: A Systematic Review and Genomic Meta-Analysis from a One-Health Perspective

2020 ◽  
Author(s):  
John Osei Sekyere ◽  
Melese Abate Reta
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
One Health ◽  
Meta Analysis ◽  
Acinetobacter Baumanii ◽  
Evolutionary Epidemiology ◽  
English Articles

AbstractObjectives/BackgroundsAntibiotic resistance (ABR) remains a major threat to public health and infectious disease management globally. However, ABR ramifications in developing countries is worsened by limited molecular diagnostics, expensive therapeutics, inadequate skilled clinicians and scientists, and unsanitary environments.MethodsData on specimens, species, clones, resistance genes, mobile genetic elements, and diagnostics were extracted and analysed from English articles published between 2015 and December 2019. The genomes and resistomes of the various species, obtained from PATRIC and NCBI, were analysed phylogenetically using RAxML and annotated with Figtree. The phylogeography of resistant clones/clades was mapped manually.Results & conclusionThirty species from 31 countries and 24 genera from 41 countries were respectively analysed from 146 articles and 3028 genomes. Genes mediating resistance to β-lactams (including blaTEM-1, blaCTX-M, blaNDM, blaIMP, blaVIM, blaOXA-48/181), fluoroquinolones (oqxAB, qnrA/B/D/S, gyrA/B and parCE mutations etc.), aminoglycosides (including armA, rmtC/F), sulphonamides (sul-1/2/3), trimethoprim (dfrA), tetracycline (tet(A/B/C/D/G/O/M/39)), colistin (mcr-1), phenicols (catA/B, cmlA), and fosfomycin (fosA) were mostly found in Enterobacter spp. and K. pneumoniae, and also in Serratia marcescens, Escherichia coli, Salmonella enterica, Pseudomonas, Acinetobacter baumannii, etc. on mostly IncF-type, IncX3/4, ColRNAI, and IncR plasmids, within IntI1 gene cassettes, insertion sequences and transposons. Clonal and multiclonal outbreaks and dissemination of resistance genes across species, countries and between humans, animals, plants and the environment were observed; E. coli ST103, K. pneumoniae ST101, S. enterica ST1/2 and V. cholerae ST69/515 were common strains. Most pathogens were of human origin and zoonotic transmissions were relatively limited. One Health studies in Africa are needed.Highlights/SignificanceAntibiotic resistance (AR) is one of the major public health threats and challenges to effective containment and treatment of infectious bacterial diseases worldwide. Herein, we used different methods to map out the geographical hotspots, sources and evolutionary epidemiology of AR. Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Acinetobacter baumanii, Pseudomonas aeruginosa, Enterobacter spp., Neisseria meningitis/gonnorhoeae, Vibrio cholerae, Campylobacter jejuni etc. were common pathogens shuttling AR genes. Transmission of same clones/strains across countries and between animals, humans, plants and the environment were observed. We recommend Enterobacter spp. or K. pneumoniae as better model/index organisms for AR surveillance.

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