Explore the vast range of titles available.

Salmonella is a major cause of foodborne illness in the United States, and antimicrobial-resistant strains pose a serious threat to public health. We used Bayesian hierarchical models of culture-confirmed infections during 2004-2016 from 2 Centers for Disease Control and Prevention surveillance systems to estimate changes in the national incidence of resistant nontyphoidal Salmonella infections. Extrapolating to the United States population and accounting for unreported infections, we estimated a 40% increase in the annual incidence of infections with clinically important resistance (resistance to ampicillin or ceftriaxone or nonsusceptibility to ciprofloxacin) during 2015-2016 (≈222,000 infections) compared with 2004-2008 (≈159,000 infections). Changes in the incidence of resistance varied by serotype. Serotypes I 4,[5],12:i:- and Enteritidis were responsible for two thirds of the increased incidence of clinically important resistance during 2015-2016. Ciprofloxacin-nonsusceptible infections accounted for more than half of the increase. These estimates can help in setting targets and priorities for prevention.

The US study used data from Laboratory-Based Enteric Disease Surveillance (https://www.cdc.gov/salmonella/reportspubs/surveillance.html) and the National Antimicrobial Resistance Monitoring System (https://www.cdc.gov/narms/index.html). For Salmonella I 4, [5],12:i;- (n = 686 isolates), ampicillin resistance increased from 20% in 2004–2008 to 53% in 2015–2016, but ceftriaxone resistance decreased from 8% to 3%. [...]increases were observed in both the United States and Canada for ciprofloxacin nonsusceptibility in Salmonella Enteritidis and for ampicillin resistance in Salmonella I 4, [5],12:i;-. David C. Alexander (Cadham Provincial Laboratory, Winnipeg, MB, Canada), Vanessa Allen (Public Health Ontario Laboratories, Toronto, ON, Canada), Sameh El Bailey (Horizon Health Network, Saint John, NB, Canada), Sadjia Bekal (Laboratoire de Santé Publique du Québec, Sainte-Anne-de-Bellevue, QC, Canada), Greg J. German (Queen Elizabeth Hospital, Charlottetown, PEI, Canada), David Haldane (Queen Elizabeth II Health Sciences Centre, Halifax, NS, Canada), Linda Hoang (British Columbia Centre for Disease Control, Vancouver, BC, Canada), Linda Chui (Alberta Precision Laboratories-Provincial Laboratory for Public Health, Edmonton, AB, Canada), Jessica Minion (Roy Romanow Provincial Laboratory, Regina, SK, Canada), and George Zahariadis (Newfoundland and Labrador Public Health and Microbiology Laboratory, St. John’s, NL, Canada) Amrita Bharat, Colleen P. Murphy, Michael R. Mulvey, Saarah Hussain, Carolee A. Carson, Richard J. Reid-SmithComments to Author , and CIPARS Provincial Partnershipsuperscript]1 Author affiliations:

Abstract Nontyphoidal Salmonella can cause gallbladder empyema and disseminated disease in patients with suppressed immune systems. We are reporting a unique case of concomitant gallbladder empyema and epidural abscess due to Salmonella enterica subsp enterica serovar Enteritidis in a patient who was appropriately treated for the primary Salmonella infection complicated by bacteremia. A high degree of suspicion is needed in high-risk patients as timely intervention can avoid life-threatening complications.

Nontyphoidal Salmonellae cause a devastating burden of invasive disease in sub-Saharan Africa with high levels of antimicrobial resistance. Vaccination has potential for a major global health impact, but no licensed vaccine is available. The lack of commercial incentive makes simple, affordable technologies the preferred route for vaccine development. Here we compare equivalent Generalized Modules for Membrane Antigens (GMMA) outer membrane vesicles and O-antigen-CRM197 glycoconjugates to deliver lipopolysaccharide O-antigen in bivalent Salmonella Typhimurium and Enteritidis vaccines. Salmonella strains were chosen and tolR deleted to induce GMMA production. O-antigens were extracted from wild-type bacteria and conjugated to CRM197. Purified GMMA and glycoconjugates were characterized and tested in mice for immunogenicity and ability to reduce Salmonella infection. GMMA and glycoconjugate O-antigen had similar structural characteristics, O-acetylation, and glucosylation levels. Immunization with GMMA induced higher anti–O-antigen IgG than glycoconjugate administered without Alhydrogel adjuvant. With Alhydrogel, antibody levels were similar. GMMA induced a diverse antibody isotype profile with greater serum bactericidal activity than glycoconjugate, which induced almost exclusively IgG1. Immunization reduced bacterial colonization of mice subsequently infected with Salmonella. S. Typhimurium numbers were lower in tissues of mice vaccinated with GMMA compared with glycoconjugate. S. Enteritidis burden in the tissues was similar in mice immunized with either vaccine. With favorable immunogenicity, low cost, and ability to induce functional antibodies and reduce bacterial burden, GMMA offer a promising strategy for the development of a nontyphoidal Salmonella vaccine compared with established glycoconjugates. GMMA technology is potentially attractive for development of vaccines against other bacteria of global health significance.

Invasive nontyphoidal Salmonella (iNTS) causes extraintestinal infections with ~15% case fatality in many countries. However, the mechanism by which iNTS emerged in China remains unaddressed. We conducted clinical investigations of iNTS infection with recurrent treatment failure, caused by underreported Salmonella enterica serovar Livingstone (SL). Genomic epidemiology demonstrated five clades in the SL population and suggested that the international animal feed trade was a likely vehicle for their introduction into China, as evidenced by multiple independent transmission incidents. Importantly, isolates from Clade‐5‐I‐a/b, predominant in China, showed an invasive nature in mice, chicken and zebrafish infection models. The antimicrobial susceptibility testing revealed most isolates (> 96%) in China are multidrug‐resistant (MDR). Overall, we offer exploiting genomics in uncovering international transmission led by the animal feed trade and highlight an emerging hypervirulent clade with increased resistance to frontline antibiotics. Synopsis The recent increase of human infections caused by invasive non‐typhoidal Salmonella , including Salmonella Livingstone, suggests their evolution towards niche adaptation to humans. This study reveals two novel subclades of S . Livingstone linked to human infections and mainly emerged in China. Genomic epidemiology showed imported animal feed was a major source of the early identified S . Livingstone in China, indicating international feed trading is a transmission route of this pathogen. Phylogeny of global Salmonella Livingstone isolates revealed five major clades of this pathogen, and clinical isolates from China largely belong to Clade‐5. Variabilities of stress responses were observed among isolates from distinct phylogenetic clades, with enhanced resistance to desiccation and diminished tolerance to oxidative stress for Clade‐5 isolates. Two novel subclades of Clade‐5 (i.e., C‐5‐I‐a/b) emerged in the last two decades and predominantly occurred in China accompanying the accumulation of antimicrobial resistance genes. The emerging clades showed significantly increased virulence in distinct animal models. i.e., chicken embryo, zebrafish embryo, and mice, indicating they have been undergoing evolution to adapt to humans. Graphical Abstract The recent increase of human infections caused by invasive non‐typhoidal Salmonella , including Salmonella Livingstone, suggests their evolution towards niche adaptation to humans. This study reveals two novel subclades of S . Livingstone linked to human infections and mainly emerged in China.

Abstract There is now a robust pipeline of licensed and World Health Organization (WHO)–prequalified typhoid conjugate vaccines with a steady progression of national introductions. However, typhoid fever is responsible for less than half the total global burden of Salmonella disease, and even less among children aged <5 years. Invasive nontyphoidal Salmonella disease is the dominant clinical presentation of Salmonella in Africa, and over a quarter of enteric fever in Asia is due to paratyphoid A. In this article, we explore the case for combination Salmonella vaccines, review the current pipeline of these vaccines, and discuss key considerations for their development, including geographies of use, age of administration, and pathways to licensure. While a trivalent typhoid/nontyphoidal Salmonella vaccine is attractive for Africa, and a bivalent enteric fever vaccine for Asia, a quadrivalent vaccine covering the 4 main disease-causing serovars of Salmonella enterica would provide a single vaccine option for global Salmonella coverage. Typhoid conjugate vaccines are efficacious against Salmonella Typhi. Globally, most Salmonella disease in humans is caused by non-Typhi Salmonella serovars. Nontyphoidal Salmonella and paratyphoid require combination Salmonella vaccines. A quadrivalent Salmonella vaccine could prevent a large majority of Salmonella disease.

Abstract Background Salmonella infections cause a disproportionately high number of deaths in Africa, especially among poor urban populations. The increasing level of multidrug-resistant (MDR) infections is a major cause of concern in these settings where alternative effective treatment is unavailable. Other options for management of these infections must be sought. The knowledge of hotspots in endemic settings can help to prioritize management and control measures in Kenya and the region. Methods Using blood cultures, we investigated children presenting with fever of unknown origin for Salmonella infections. We performed antimicrobial susceptibility testing and whole genome sequencing to further characterize Salmonella isolates. Using Global Positioning System technologies, we mapped Salmonella isolates to households of patients in the study site and determined risk factors associated with high concentration of cases in particular sites. Results A total of 281 Salmonella species (149 from blood and 132 from fecal samples) from febrile children <5 years of age were studied. These consisted of 85 Salmonella Typhimurium, 58 Salmonella Enteritidis, 32 other nontyphoidal Salmonella (NTS) serotypes, and 126 Salmonella Typhi. The prevalence of MDR invasive NTS (iNTS) was 77.2%, with 15% resistant to ceftriaxone, a drug that is last-line treatment for iNTS and other severe gram-negative infections in Kenya. Invasive NTS and S. Typhi together mapped around common water vending points and close to sewer convergence points in the highly populated village. Conclusions These hotspots could be targeted for management and control strategies, including a combined introduction of typhoid and iNTS vaccines, aimed at reducing transmission in these endemic settings.

Background. Salmonella causes an estimated 100 000 antimicrobial-resistant infections annually in the United States. Salmonella antimicrobial resistance may result in bacteremia and poor outcomes. We describe antimicrobial resistance among nontyphoidal Salmonella blood isolates, using data from the National Antimicrobial Resistance Monitoring System. Methods. Human nontyphoidal Salmonella isolates from 2003 to 2013 were classified as fully susceptible, resistant to ≥1 anti-microbial agent, or resistant to a first-line agent. Logistic regression was used to compare resistance patterns, serotypes, and patient characteristics for Salmonella isolated from blood versus stool and to determine resistance trends over time. Results. Approximately 20% of blood isolates had antimicrobial resistance to a first-line treatment agent. Bacteremia was associated with male sex, age ≥65 years, and specific serotypes. Blood isolates were more likely to be resistant to ≥1 agent for serotypes Enteritidis, Javiana, Panama, and Typhimurium. Blood isolates were most commonly resistant to tetracycline (19%), and more likely resistant to a first-line agent (odds ratio, 1.81; 95% confidence interval, 1.56–2.11) than stool isolates. Ceftriaxone resistance increased in blood isolates from 2003 to 2013 (odd ratio, 1.12; 95% confidence interval, 1.02–1.22). Conclusions. Resistance to first-line treatment agents in patients with Salmonella bacteremia is a concern for public health and for informing clinical decisions. Judicious antimicrobial use is crucial to limit resistance.

Background Nontyphoidal Salmonella (NTS) is the most commonly reported foodborne gastrointestinal infection and ranks among the top three causes of foodborne bacterial outbreaks in China. Methods This study analyzed NTS data from the Foodborne Disease Surveillance System in China from 2013 to 2022 to summarize epidemiological features and assess reporting rate changes. We employed joinpoint regression model to calculate the annual percentage change in NTS reporting rate, sex reporting rate, as well as rural-urban reporting rate. We applied the Pearson correlation coefficient to evaluate the correlation of NTS reporting rate and the national per capita consumption of major foods and cases of COVID-19. Results During this period, 55,266 NTS cases were reported, with reporting rates increasing significantly (AAPC [CRR] = 21.89%). Urban areas accounted for 70.06% of cases, but rural patients had higher hospitalization rates than urban ones (41.54% vs. 33.69%, p  < 0.001). Children aged 0–4 years constituted 53.59% of cases and showed higher hospitalization rates ( p  < 0.05). Salmonella Typhimurium (31.07%) and Enteritidis (15.89%) were the leading serotypes. NTS reporting rates were strongly correlated with national per-capita consumption of fruit ( r  = 0.98), poultry ( r  = 0.95), aquatic products ( r  = 0.95), eggs ( r  = 0.94), vegetables ( r  = 0.79), dairy ( r  = 0.73), and meat ( r  = 0.65). Conclusion This study highlights the growing public health burden of Salmonella infection in China, with a sharp rise in reporting rates and major rural-urban differences. Over half of the cases involved children under 5 years old, underscoring the urgent need to enhance food safety measures, particularly for vulnerable populations.

Abstract Background Despite the known association between microorganisms and development of inflammatory bowel disease (IBD), the role of nontyphoidal Salmonella (NTS) in IBD is not adequately addressed. We aimed at elucidating the relationship between NTS infection and the risk of IBD. Methods Based on the National Health Insurance Research Database in Taiwan, this retrospective cohort study enrolled patients with NTS infection (exposure group; n = 4651) and those without NTS infection (comparator group; n = 4651) who were propensity score matched (1:1) by demographic data, medications, comorbidities, and index date. All patients were followed until IBD onset, individual mortality, or December 31, 2018. Cox proportional hazards regression analysis was performed to determine the hazard ratios and 95% confidence intervals (CIs). Sensitivity analyses were used for cross-validation. Results The NTS group demonstrated an increased risk of IBD compared with the non-NTS groups (adjusted hazard ratio [aHR], 2.12; 95% CI, 1.62-2.78) with a higher risk of developing ulcerative colitis in the former (aHR, 2.27; 95% CI, 1.69-3.04). Nevertheless, the small sample size may contribute to lack of significant difference in Crohn’s disease. Consistent findings were noted after excluding IBD diagnosed within 6 months of NTS infection (aHR, 2.28; 95% CI, 1.71-3.03), excluding those with enteritis/colitis before index date (aHR, 1.85; 95% CI, 1.28-2.68), excluding those using antibiotics for 1 month in the year before IBD onset (aHR, 1.81; 95% CI, 1.34-2.45), inverse probability of treatment weighting (aHR, 1.64; 95% CI, 1.31-2.04), and inclusion of individuals regardless of age (n = 10 431; aHR, 1.83; 95% CI, 1.53-2.19). Conclusions Patients with NTS were associated with an increased risk of developing IBD, especially ulcerative colitis.