scholarly journals Municipal Wastewater Surveillance Revealed a High Community Disease Burden of a Rarely Reported and Possibly Subclinical Salmonella enterica Serovar Derby Strain

2020 ◽  
Vol 86 (17) ◽  
Author(s):  
Sabrina Diemert ◽  
Tao Yan
Keyword(s):  
Infectious Disease ◽  
Salmonella Enterica ◽  
Disease Burden ◽  
Municipal Wastewater ◽  
Enteric Pathogens ◽  
Whole Genome Sequencing Data ◽  
Subclinical Infection ◽  
Infection Rates ◽  
Sampling Campaign ◽  
Clinical Cases

ABSTRACT Clinical surveillance of enteric pathogens like Salmonella is integral to track outbreaks and endemic disease trends. However, clinic-centered disease monitoring biases toward detection of severe cases and underestimates the incidence of self-limiting gastroenteritis and asymptomatic strains. Monitoring pathogen loads and diversity in municipal wastewater (MW) can provide insight into asymptomatic or subclinical infections which are not reflected in clinical cases. Subclinical infection patterns may explain the unusual observation from a year-long sampling campaign in Hawaii: Salmonella enterica serovar Derby was the most abundant pulsotype in MW but was detected infrequently in clinics over the sampling period. Using whole-genome sequencing data of Salmonella isolates from MW and public databases, we demonstrate that the Derby serovar has lower virulence potential than other clinical serovars, particularly based on its reduced profile of genes linked with immune evasion and symptom production, suggesting its potential as a subclinical salmonellosis agent. Furthermore, MW had high abundance of a rare Derby sequence type (ST), ST-72 (rather than the more common ST-40). ST-72 isolates had higher frequencies of fimbrial adherence genes than ST-40 isolates; these are key virulence factors involved in colonization and persistence of infections. However, ST-72 isolates lack the Derby-specific Salmonella pathogenicity island 23 (SPI-23), which invokes host immune responses. In combination, ST-72’s genetic features may lead to appreciable infection rates without obvious symptom production, allowing for subclinical persistence in the community. This study demonstrated wastewater’s capability to provide community infectious disease information—such as background infection rates of subclinical enteric illness—which is otherwise inaccessible through clinical approaches. IMPORTANCE Wastewater-based epidemiology (WBE) has been conventionally used to analyze community health via the detection of chemicals, such as legal and illicit drugs; however, municipal wastewater contains microbiological determinants of health and disease as well, including enteric pathogens. Here, we demonstrate that WBE can be used to examine subclinical community salmonellosis patterns. Derby was the most abundant Salmonella serovar detected in Hawaii wastewater over a year-long sampling study, with few corresponding clinical cases. Comparative genomics analyses indicate that the normally rare strain of S. Derby found in wastewater has a unique combination of genes which allow it to persist as a subclinical infection without producing symptoms of severe gastroenteritis. This study shows that WBE can be used to explore trends in community infectious disease patterns which may not be reflected in clinical monitoring, shedding light on overall enteric disease burden and rates of asymptomatic cases.

scholarly journals Clinically Unreported Salmonellosis Outbreak Detected via Comparative Genomic Analysis of Municipal Wastewater Salmonella Isolates

2019 ◽  
Vol 85 (10) ◽  
Author(s):  
Sabrina Diemert ◽  
Tao Yan
Keyword(s):  
Public Health ◽  
Infectious Disease ◽  
Salmonella Enterica ◽  
Municipal Wastewater ◽  
Disease Outbreaks ◽  
Easy Access ◽  
Great Promise ◽  
Content Type ◽  
Health Clinics ◽  
Paratyphi B

ABSTRACT Municipal wastewater includes human waste that contains both commensal and pathogenic enteric microorganisms, and this collective community microbiome can be monitored for community diseases. In a previous study, we assessed the salmonellosis disease burden using municipal wastewater from Honolulu, Hawaii, which was monitored over a 54-week period. During that time, a strain of Salmonella enterica serovar Paratyphi B variant L(+) tartrate(+) (also known as Salmonella enterica serovar Paratyphi B variant Java) was identified; this strain was detected simultaneously with a clinically reported outbreak, and pulsed-field gel electrophoresis patterns were identical for clinical and municipal wastewater isolates. Months after the outbreak subsided, the same pulsotype was detected as the dominant pulsotype in municipal wastewater samples, with no corresponding clinical cases reported. Using genomic characterization (including core single-nucleotide polymorphism alignment, core genome multilocus sequence typing, and screening for virulence and antibiotic resistance genes), all S. Java municipal wastewater isolates were determined to be clonal, indicating a resurgence of the original outbreak strain. This demonstrates the feasibility and utility of municipal wastewater surveillance for determining enteric disease outbreaks that may be missed by traditional clinical surveillance methods. IMPORTANCE Underdetection of microbial infectious disease outbreaks in human communities carries enormous health costs and is an ongoing problem in public health monitoring (which relies almost exclusively on data from health clinics). Surveillance of municipal wastewater for community-level monitoring of infectious disease burdens has the potential to fill this information gap, due to its easy access to the mixed community microbiome. In the present study, the genomes of 21 S. Java isolates (collected from municipal wastewater in Honolulu) were analyzed; results showed that the same Salmonella strain that caused a known salmonellosis clinical outbreak in spring 2010 remerged as the most dominant strain in municipal wastewater in spring 2011, indicating a new outbreak that was not detected by health clinics. Our results show that wastewater monitoring holds great promise to inform the field of public health regarding outbreak status within communities.

Effect of plant systemic resistance elicited by biological and chemical inducers on the colonization of the lettuce and basil leaf apoplast by Salmonella enterica

2021 ◽  
Author(s):  
L. Chalupowicz ◽  
S. Manulis-Sasson ◽  
I. Barash ◽  
Y. Elad ◽  
D. Rav-David ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Microbial Contamination ◽  
Mitigation Strategies ◽  
Enteric Pathogens ◽  
Leafy Vegetables ◽  
Population Increase ◽  
Systemic Resistance ◽  
Post Inoculation ◽  
Proof Of Concept ◽  
Leaf Apoplast

Mitigation strategies to prevent microbial contamination of crops are lacking. We tested the hypothesis that induction of plant systemic resistance by biological (ISR) and chemical (SAR) elicitors reduces endophytic colonization of leaves by Salmonella enterica serovars Senftenberg and Typhimurium. S . Senftenberg had greater endophytic fitness than S . Typhimurium in basil and lettuce. The apoplastic population sizes of serovars Senftenberg and Typhimurium in basil and lettuce, respectively, were significantly reduced approximately 10- to 100-fold by root treatment with microbial inducers of systemic resistance compared with the H 2 O treatment. Rhodotorula glutinis effected the lowest population increase of S . Typhimurium in lettuce (120-fold) and S . Senftenberg in basil leaves (60-fold) compared with the H 2 O treatment over 10 days post-inoculation. Trichoderma harzianum and Pichia guilliermondii did not have any significant effect on S . Senftenberg in the basil apoplast. The chemical elicitors acidobenzolar-S-methyl and DL-β-amino-butyric acid inhibited S . Typhimurium multiplication in the lettuce apoplast 10- and 2-fold, respectively, compared with H 2 O-treated plants. All ISR and SAR inducers applied to lettuce roots in this study increased leaf expression of the defense gene PR1 , as did Salmonella apoplastic colonization in H 2 O-treated lettuce plants. Remarkably, both acidobenzolar-S-methyl- and R. glutinis -upregulation of PR1 was repressed by the presence of Salmonella in the leaves. However, enhanced PR1 expression was sustained longer and at greater levels upon elicitor treatment than by Salmonella induction alone. These results serve as proof of concept that priming of plant immunity may provide an intrinsic hurdle against the endophytic establishment of enteric pathogens in leafy vegetables. Importance Fruit and vegetables consumed raw have become an important vehicle of foodborne illness despite a continuous effort to improve their microbial safety. Salmonella enterica has caused numerous recalls and outbreaks of infection associated with contaminated leafy vegetables. Evidence is increasing that enteric pathogens can reach the leaf apoplast where they confront plant innate immunity. Plants may be triggered for induction of their defense signaling pathways by exposure to chemical or microbial elicitors. This priming for recognition of microbes by plant defense pathways has been used to inhibit plant pathogens and limit disease. Given that current mitigation strategies are insufficient in preventing microbial contamination of produce and associated outbreaks, we investigated the effect of plant induced resistance on S. enterica colonization of the lettuce and basil leaf apoplast in order to gain a proof of concept for the use of such an intrinsic approach to inhibit human pathogens in leafy vegetables.

scholarly journals Diffusible Signal Factors Act through AraC-Type Transcriptional Regulators as Chemical Cues To Repress Virulence of Enteric Pathogens

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Erick Maosa Bosire ◽  
Colleen R. Eade ◽  
Carl J. Schiltz ◽  
Amanda J. Reid ◽  
Jerry Troutman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Salmonella Enterica ◽  
Unsaturated Fatty Acids ◽  
Virulence Gene ◽  
Transcriptional Regulators ◽  
Enteric Pathogens ◽  
Hexadecenoic Acid ◽  
Content Type ◽  
Virulence Gene Expression

ABSTRACT Successful colonization by enteric pathogens is contingent upon effective interactions with the host and the resident microbiota. These pathogens thus respond to and integrate myriad signals to control virulence. Long-chain fatty acids repress the virulence of the important enteric pathogens Salmonella enterica and Vibrio cholerae by repressing AraC-type transcriptional regulators in pathogenicity islands. While several fatty acids are known to be repressive, we show here that cis-2-unsaturated fatty acids, a rare chemical class used as diffusible signal factors (DSFs), are highly potent inhibitors of virulence functions. We found that DSFs repressed virulence gene expression of enteric pathogens by interacting with transcriptional regulators of the AraC family. In Salmonella enterica serovar Typhimurium, DSFs repress the activity of HilD, an AraC-type activator essential to the induction of epithelial cell invasion, by both preventing its interaction with target DNA and inducing its rapid degradation by Lon protease. cis-2-Hexadecenoic acid (c2-HDA), a DSF produced by Xylella fastidiosa, was the most potent among those tested, repressing the HilD-dependent transcriptional regulator hilA and the type III secretion effector sopB >200- and 68-fold, respectively. Further, c2-HDA attenuated the transcription of the ToxT-dependent cholera toxin synthesis genes of V. cholerae. c2-HDA significantly repressed invasion gene expression by Salmonella in the murine colitis model, indicating that the HilD-dependent signaling pathway functions within the complex milieu of the animal intestine. These data argue that enteric pathogens respond to DSFs as interspecies signals to identify appropriate niches in the gut for virulence activation, which could be exploited to control the virulence of enteric pathogens.

Characterization of screenings from three municipal wastewater treatment plants in the Region Rhône-Alpes

2009 ◽  
Vol 60 (2) ◽  
pp. 525-531 ◽  
Author(s):  
R. Le Hyaric ◽  
J.-P. Canler ◽  
B. Barillon ◽  
P. Naquin ◽  
R. Gourdon
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Dry Weight ◽  
Matter Content ◽  
Municipal Wastewater Treatment ◽  
Production Rates ◽  
Sampling Campaign ◽  
Average Production ◽  
Municipal Wastewater Treatment Plants

The objective of this study was to analyze the composition of the screenings sampled from three municipal wastewater treatment plants (wwtp) located in the Region Rhône-Alpes, France. The plants were equipped with multi screening stages with gap sizes ranging from 60 to 3 mm. Waste production flows from each plant were monitored over at least 48 hours in each sampling campaign in order to calculate average production rates. Waste samples of at least 7 kg were collected from each screening stage in each plant at different seasons to evaluate the influence of different parameters on the composition of the waste. An overall 30 samples were thereby collected between May 2007 and February 2008, dried at 80°C for a week, and subsequently hand sorted into 10 fractions of waste materials. Results showed that the average production varied between 0.53 and 3.49 kg (wet mass) per capita per year. The highest production rates were observed during or immediately after rainy weather conditions. The dry matter content ranged between 14.4 and 29.2% of wet mass, and the volatile matter content was between 70.0 and 90.5% of dry mass. The predominant materials in the screenings were found to be sanitary textiles which accounted for 65.2% to 73.6% of dry weight and fines (<20 mm) which accounted for 15.2% to 18.2% of dry weight. These proportions were relatively similar in each plant and each sampling campaign.

scholarly journals Acquisition of virulence-associated factors by the enteric pathogens Escherichia coli and Salmonella enterica

2001 ◽  
Vol 356 (1411) ◽  
pp. 1027-1034 ◽  
Author(s):  
John Wain ◽  
Deborah House ◽  
Derek Pickard ◽  
Gordon Dougan ◽  
Gad Frankel
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Salmonella Enterica ◽  
Associated Factors ◽  
Enteric Pathogens ◽  
Genomic Studies ◽  
Shed Light

In this review we summarize recent genomic studies that shed light on the mechanism through which pathogenic Escherichia coli and Salmonella enterica have evolved. We show how acquisition of DNA at specific sites on the chromosome has contributed to increased genetic variation and virulence of these two genera of the Enterobacteriaceae.

scholarly journals Infectious disease burden in Gujarat (2005–2011): comparison of selected infectious disease rates with India

2014 ◽  
Vol 7 (1) ◽  
pp. 22838 ◽  
Author(s):  
Veena Iyer ◽  
Gulrez Shah Azhar ◽  
Nandini Choudhury ◽  
Vidwan Singh Dhruwey ◽  
Russell Dacombe ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Disease Burden ◽  
Disease Rates

scholarly journals Removal of Enteric Pathogens from Real Wastewater Using Single and Catalytic Ozonation

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 127 ◽  
Author(s):  
João Gomes ◽  
Danilo Frasson ◽  
Rosa Quinta-Ferreira ◽  
Ana Matos ◽  
Rui Martins
Keyword(s):  
Volcanic Rock ◽  
Emerging Contaminants ◽  
Municipal Wastewater ◽  
Jc Virus ◽  
Low Cost ◽  
Catalytic Ozonation ◽  
Enteric Pathogens ◽  
Treated Wastewater ◽  
Genotype I ◽  
Treatment Technologies

Water scarcity is one of the main problems of this century. Water reclamation appears as an alternative due to the reuse of treated wastewater. Therefore, effluents treatment technologies (activated sludge, rotary biological discs, percolating beds) must be improved since they are not able to remove emerging contaminants such as enteric pathogens (bacteria and virus). These pollutants are difficult to remove from the wastewater and lead to adverse consequences to human health. Advanced oxidation processes, such as single and catalytic ozonation, appear as suitable complements to conventional processes. Catalytic ozonation was carried out using a low-cost material, a volcanic rock. Single and catalytic ozonation were capable of promoting total Escherichia coli removal from municipal wastewater after 90 min of contact. The presence of volcanic rock increases disinfection efficiency since E. coli regrowth was not observed. The identified viruses (Norovirus genotype I and II and JC virus) were completely removed using catalytic ozonation, whereas single ozonation was not able to eliminate JC virus even after 150 min of treatment. The higher performance of the catalytic process can be explained by the formation of hydroxyl radicals, proving that disinfection occurs in the liquid bulk and not due to adsorption at the volcanic rock.

scholarly journals Seventy-five years of estimating the force of infection from current status data

2009 ◽  
Vol 138 (6) ◽  
pp. 802-812 ◽  
Author(s):  
N. HENS ◽  
M. AERTS ◽  
C. FAES ◽  
Z. SHKEDY ◽  
O. LEJEUNE ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Disease Burden ◽  
Parvovirus B19 ◽  
Current Status Data ◽  
Current Status ◽  
Force Of Infection ◽  
Status Data ◽  
Notification Data ◽  
Case Notification ◽  
Key Parameter

SUMMARYThe force of infection, describing the rate at which a susceptible person acquires an infection, is a key parameter in models estimating the infectious disease burden, and the effectiveness and cost-effectiveness of infectious disease prevention. Since Muench formulated the first catalytic model to estimate the force of infection from current status data in 1934, exactly 75 years ago, several authors addressed the estimation of this parameter by more advanced statistical methods, while applying these to seroprevalence and reported incidence/case notification data. In this paper we present an historical overview, discussing the relevance of Muench's work, and we explain the wide array of newer methods with illustrations on pre-vaccination serological survey data of two airborne infections: rubella and parvovirus B19. We also provide guidance on deciding which method(s) to apply to estimate the force of infection, given a particular set of data.

scholarly journals Contribution of the Salmonella enterica KdgR Regulon to Persistence of the Pathogen in Vegetable Soft Rots

2015 ◽  
Vol 82 (4) ◽  
pp. 1353-1360 ◽  
Author(s):  
Andrée S. George ◽  
Isai Salas González ◽  
Graciela L. Lorca ◽  
Max Teplitski
Keyword(s):  
Gene Expression ◽  
Salmonella Enterica ◽  
Carbon Sources ◽  
Soft Rot ◽  
Enteric Pathogens ◽  
Pectobacterium Carotovorum ◽  
Pectin Degradation ◽  
Content Type ◽  
Gene Expression Analyses ◽  
Uptake And Metabolism

ABSTRACTDuring their colonization of plants, human enteric pathogens, such asSalmonella enterica, are known to benefit from interactions with phytopathogens. At least in part, benefits derived bySalmonellafrom the association with a soft rot caused byPectobacterium carotovorumwere shown to be dependent onSalmonellaKdgR, a regulator of genes involved in the uptake and utilization of carbon sources derived from the degradation of plant polymers. ASalmonellakdgRmutant was more fit in soft rots but not in the lesions caused byXanthomonasspp. andPseudomonasspp. Bioinformatic, phenotypic, and gene expression analyses demonstrated that the KdgR regulon included genes involved in uptake and metabolism of molecules resulting from pectin degradation as well as those central to the utilization of a number of other carbon sources. Mutant analyses indicated that the Entner-Doudoroff pathway, in part controlled by KdgR, was critical for the persistence within soft rots and likely was responsible for thekdgRphenotype.

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