Non-typhoidal Salmonella Infection Research Articles

The Economic Burden of Non-Typhoidal Salmonella and Invasive Non-Typhoidal Salmonella Infection: A Systematic Literature Review

Non-typhoidal Salmonella (NTS) infection and invasive non-typhoidal Salmonella (iNTS) infection cause a significant global health and economic burden. This systematic review aims to investigate the reported economic burden of NTS and iNTS infection, identify research gaps, and suggest future research directions. Data from PubMed and Embase databases up to April 2022 were reviewed, and articles were screened based on predefined criteria. Cost data were extracted, categorized into direct medical costs (DMCs), direct non-medical costs (DNMCs), and indirect costs (ICs), and converted into US dollars (year 2022). Data primarily originated from high-income countries (37 out of 38), with limited representation from Africa and resource-limited settings. For inpatients, DMCs were the primary cost driver for both NTS and iNTS illnesses, with estimates ranging from USD 545.9 (Taiwan, a region of China) to USD 21,179.8 (Türkiye) for NTS and from USD 1,973.1 (Taiwan, a region of China) to USD 32,507.5 (United States of America) for iNTS per case. DNMCs and ICs varied widely across studies. Although study quality improved over time, methodological differences persisted. This review underscores the lack of economic data on NTS and iNTS in resource-limited settings. It also highlights the need for economic burden data in resource-limited settings and a standardized approach to generate global datasets, which is critical for informing policy decisions, especially regarding future vaccines.

Increased Risk of Inflammatory Bowel Disease Among Patients With Nontyphoidal Salmonella Infections: A Population-Based Cohort Study.

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. 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. 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). Patients with NTS were associated with an increased risk of developing IBD, especially ulcerative colitis.

Time-dependent risk of atopic dermatitis following nontyphoidal Salmonella infection.

The pathogenesis of atopic dermatitis (AD) remains unclear. Nontyphoidal Salmonella (NTS) infection might trigger immune-mediated reactions. We aimed to examine NTS and the risk of subsequent AD. From 2002 to 2015, eligible patients (aged 0-100 years) with NTS were identified. NTS and non-NTS groups were matched at a 1:10 ratio on age and sex. We utilized conditional multivariable Cox proportional hazard models to estimate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) for AD development. Subgroup analyses were conducted based on age, sex, and severity of NTS infection. We utilized landmark analysis to explore the time-dependent hazard of AD following NTS. In the NTS group (N = 6624), 403 developed AD. After full adjustment of demographics and comorbidities, the NTS group had a higher risk of AD than the reference group (aHR = 1.217, 95% CI = 1.096-1.352). Age-stratified analysis revealed that NTS group exhibited an elevated risk compared to the reference group, particularly among those aged 13-30 years (aHR = 1.25, 95% CI = 1.017-1.559), individuals aged 31-50 years (aHR = 1.388, 95% CI = 1.112-1.733), those aged 51-70 years (aHR = 1.301, 95% CI = 1.008-1.679), and individuals aged 71 years and over (aHR = 1.791, 95% CI = 1.260-2.545). Severe NTS was associated with a higher risk of AD than the reference group (aHR = 2.411, 95% CI = 1.577-3.685). Landmark analysis showed generally consistent findings. Minimizing exposure to NTS infection may represent a prospective strategy for averting the onset and progression of atopic dermatitis.

Impact of COVID-19-related nonpharmaceutical interventions on diarrheal diseases and zoonotic Salmonella

Non-pharmaceutical interventions (NPIs) have been proven effective in reducing the spread of the coronavirus disease 2019 (COVID-19), but their broader impact on gastrointestinal disorders remains poorly studied. Here, we report an observational analysis and retrospective study that compares the incidence of acute diarrheal diseases in Hangzhou, Zhejiang, China, between 2019 and 2020, with an examination of the antimicrobial resistance and genetic spectrum of non-typhoidal Salmonella (NTS) from 2015 to 2022, before and during the COVID-19 pandemic. Our findings underscore that NPIs related to COVID-19 effectively reduced the incidence of acute diarrhea, with a substantial decrease in most enteric pathogens. Notably, NTS exhibited an unexpected surge. Further genomic investigations of NTS isolates revealed an overall reduction in antimicrobial-resistant (AMR), disinfection-tolerant, and virulent capabilities, but with marked variations detected between human and animal isolates. Additional genome-based analysis confirmed a decrease in the scale of zoonotic transmission in response to NPIs, suggesting particular NTS types may contribute to human infections via alternative pathways. The collective findings manifested that COVID-19-related NPIs had a mixed impact on NTS infections, which may inform AMR NTS mitigation policy.

Salmonella infections in Denmark from 2013–2022 with focus on serotype distribution, invasiveness, age, sex, and travel exposition

PurposeTo analyze the nationwide incidence of Salmonella infections in Denmark from 2013 to 2022.MethodsConfirmed cases of Salmonella enterica subsp. enterica were examined using the National Register of Enteric Pathogens during 2013–2022. Proportions, incidence rates (IR), relative risk (RR), and 95% confidence intervals (CI) were calculated to assess differences in serotypes, invasiveness, age, sex, and travel exposure.ResultsWe identified 9,944 Danish Salmonella enterica subsp. enterica cases, with an average annual incidence rate of 16.9 per 100,000 inhabitants, declining during the COVID-19 pandemic. Typhoidal cases totaled 206, with an average annual IR of 0.35 per 100,000 inhabitants. Enteric fever patients had a median age of 24 years (IQR:17–36). Leading non-typhoid Salmonella (NTS) serotypes were S. Enteritidis (26.4%), monophasic S. Typhimurium (16.5%), and S. Typhimurium (13.5%). Median age for NTS cases was 42 (IQR: 18–62), with even sex distribution, and a third reported travel prior to onset of disease. The overall percentage of invasive NTS (iNTS) infection was 8.1% (CI: 7.6–8.7). Eleven serotypes were associated with higher invasiveness, with S. Dublin and S. Panama having the highest invasiveness with age and sex-adjusted RR of 7.31 (CI: 6.35–8.43) and 5.42 (CI: 3.42–8.60), respectively, compared to all other NTS serotypes. Increased age was associated with higher RR for iNTS infection.ConclusionDuring the decade, there was a limited number of typhoidal cases. The dominant NTS serotypes were S. Enteritidis and monophasic S. Typhimurium, whereas S. Dublin and S. Panama exhibited the highest invasive potential.

Influence of Incubation Condition on the Antibiotic Susceptibility of Salmonella

Bacteria experience changes in physiology and growth patterns in aerobic laboratory culture and the anaerobic gastrointestinal tract of the host. Our study hypothesizes that this physiological difference influences the antibiotic susceptibility/resistance pattern of Salmonella in aerobic and anaerobic conditions. The susceptibility and resistance percentage was determined using the diameter of the zone of inhibition for ten major classes of antibiotic drugs with a total of sixteen molecules. Data were analyzed in GraphPad Prism vs 8 using a two-way ANOVA analysis for the six antibiotics selected based on the greatest differences in the zone of inhibition. The highest observed resistance levels were against nalidixic acid (63.8%/48.6%) and tetracycline (65.2%/58.6%), followed by trimethoprim/ sulphamethoxazole (52.2%/50%), cephalexin (50.7%/52.9%), ciprofloxacin (45.7%/45.7%), amoxicillin (43.5%/47.1%), ampicillin (37.7%/45.7%) and chloramphenicol (36.2%/37.1%) in aerobic/anaerobic condition. The variation contributed by the type of antibiotic on the degree of resistance was 72.73% (P=0.0303) and the variation contributed by the incubation condition was 16.09% (P=0.0437), both of which are statistically significant. The findings of our study demonstrate that the susceptibility/resistance of non-typhoidal Salmonella varies in aerobic and anaerobic incubation. Hence, pharmacodynamics models aiming to evaluate the impact of antimicrobial use in enteric bacteria such as Salmonella of the treated host should utilize measurements of bacterial susceptibility that are obtained anaerobically (as well as aerobically) to achieve effective antimicrobial treatment and control non-typhoidal salmonella infections.

Molecular Epidemiology of Fluoroquinolones Resistance Genes among Non-typhoidal Salmonella Species from Humans and Poultry Faeces in Ido-Ekiti, Ekiti State

Non-typhoidal Salmonella (NTS) strains are among the most common bacterial pathogens associated with antimicrobial resistance (AMR) where animals are known to be the major reservoir of NTS despite improvements in hygiene and sanitation. This study aimed to investigate the prevalence and basis of fluoroquinolone resistance genes in non-typhoidal Salmonella (NTS) recovered from human and poultry fecal samples in Ido Ekiti. The study used a total of 300 fecal samples,100 from humans and 200 from poultry sources. Faecal samples were cultured using Selenite F broth and XLD agar. Isolates were identified using morphology, biochemical tests, and molecular characterization. Antibiotic susceptibility were determined using disc diffusion test. Plasmid extraction and curing were done using alkaline lysis and Ethidium Bromide. Phylogenetic relatedness was determined using the Unweighted Pair Group Method with Arithmetic Mean. The results revealed that 10.7% of NTS were identified, with 9% from human and 11.5% from poultry sources. High resistance to ofloxacin (77.8%) was observed in both human and poultry samples. S. enteritidis from human sources had a concomitant presence of two qnr genes (qnrA and qnrS) at 20%, while only qnrS (60%) was detected from poultry sources. Statistically significant risk factors for NTS infection among human included the consumption of poultry products and the use of untreated poultry droppings. The study identified Qnr resistance gene in ESBL producing S. enteritidis from both human and poultry sources in Ido Ekiti and are plasmid borne, establishing the role of plasmids in the acquisition, and spread of antibiotic resistance of fluoroquinolones.

The Rise of Non-typhoidal Salmonella Infections in India: Causes, Symptoms, and Prevention.

Non-typhoidal Salmonella infections (NTS) are a growing concern in India, posing a significant health risk to the population. These infections are becoming more common at worrisome rates, primarily because of inadequate surveillance. Salmonella non-typhoidal causes severe gastroenteritis andcan even cause invasive infections, such as bacteremia, and focal infections, such as meningitis and septic arthritis, and is acquired through contaminated food and water sources. From moderate to severe, the symptoms might vary. Certain serovars exhibit a stronger propensity for specific syndromes, with serious infections more commonly observed in vulnerable populations. Consuming contaminated food, using inadequate sanitationprocedures while handling meat from animals slaughtered, and contaminated water supplies are some of the causes of these diseases. Proper food and water treatment, better sanitary facilities, public awareness campaigns, and adherence to food safety laws are all part of prevention measures. The issue of antimicrobial resistance further emphasizes the necessity for prudent antibiotic usage. The Indian government has put in place programsincluding public awareness campaigns, better sanitary facilities, and stricter food safety laws. In the future, efforts should, however, concentrate on improving laws, boosting hygienic practices, and funding the development of new medicines and vaccines. These actions will lessen the burden of NTS infections in India by assisting in their prevention and management. This review aims to understand the reasons for this growing tendency, which is essential for creating efficient control and prevention strategies.

Epidemiological, Genetic, and Phenotypic Characteristics of Non-Typhoidal Salmonella in Young Children, as Obtained from a Tertiary Hospital in Guangzhou, China.

Gastroenteritis caused by non-typhoidal Salmonella (NTS) is a significant disease in childhood, ranking as the seventh-leading cause of diarrhea mortality in children aged < 5 years. To understand the epidemiological, genetic, and phenotypic characteristics of NTS, 465 anal swabs from children aged < 5 years in a tertiary hospital in Conghua District, Guangzhou, China, were collected from June to October 2021. An average prevalence of 35.27% (164/465) was observed, with whole genome sequencing identifying 11 serotypes, among which Salmonella 1,4,[5],12:i:- was the most prevalent (65.24%, 107/164). Meanwhile, ST34 was found to be the predominant subtype. Children who are breastfed, eat fresh food, and have good hygiene habits show a relatively low prevalence of NTS. Fever is a common symptom that may be caused by NTS infection. Antimicrobial resistance testing revealed that the majority of strains were resistant to tetracycline (83.5%) and ampicillin (82.3%), with multi-drug resistance (MDR) observed in 50.61% (83/164) of all strains tested. The predominant resistance spectrum presents as tetracycline-ampicillin-chloramphenicol-trimethoprim-sulfamethoxazole (30.49%, 50/164). The antimicrobial resistance rates (2.4%, 9.8%, 9.8%, 10.4%, 9.1%, and 3.7%, respectively) of cephalosporins (cefepime, cefuroxime, cefuroxime axetil, ceftriaxone, ceftazidime, and cefoxitin) were low. Therefore, continued surveillance of the prevalence and MDR profiles of NTS, along with the rational use antibiotics, is required. This protocol is significant for preventing further dissemination of NTS and formulating effective prevention and control strategies.

Infections due to Salmonella sp. in children with chronic granulomatous disease: Our experience from North India

Infections with non-typhoidal Salmonella sp. have been documented in children with chronic granulomatous disease (CGD), but the prevalence of salmonella infection in children with CGD in underdeveloped countries is unknown. We assessed the clinical profiles of CGD patients diagnosed at our tertiary care centre in north India and had Salmonella sp.infections. We found three patients with Salmonella sp. bloodstream infections (2-proven, 1-probable) among the 99 CGD patients. After receiving cotrimoxazole prophylaxis following a CGD diagnosis, we noted that none of our patients experienced non-typhoidal salmonella infection. One patient experienced severe typhoidal bacteremia despite receipt of cotrimoxazole prophylaxis. This patient required numerous hospital admissions and prolonged intravenous antibiotic regimen. We suggest that vaccination with killed typhoidal vaccines should be regularly given to children with CGD in order to avoid typhoidal bacteremia, in addition to cotrimoxazole prophylaxis and a focus on good hand and food hygiene.

Genomic diversity and epidemiological significance of non-typhoidal Salmonella found in retail food collected in Norfolk, UK.

Non-typhoidal Salmonella (NTS) is a major cause of bacterial gastroenteritis. Although many countries have implemented whole genome sequencing (WGS) of NTS, there is limited knowledge on NTS diversity on food and its contribution to human disease. In this study, the aim was to characterise the NTS genomes from retail foods in a particular region of the UK and assess the contribution to human NTS infections. Raw food samples were collected at retail in a repeated cross-sectional design in Norfolk, UK, including chicken (n=311), leafy green (n=311), pork (n=311), prawn (n=279) and salmon (n=157) samples. Up to eight presumptive NTS isolates per positive sample underwent WGS and were compared to publicly available NTS genomes from UK human cases. NTS was isolated from chicken (9.6 %), prawn (2.9 %) and pork (1.3 %) samples and included 14 serovars, of which Salmonella Infantis and Salmonella Enteritidis were the most common. The S. Enteritidis isolates were only isolated from imported chicken. No antimicrobial resistance determinants were found in prawn isolates, whilst 5.1 % of chicken and 0.64 % of pork samples contained multi-drug resistant NTS. The maximum number of pairwise core non-recombinant single nucleotide polymorphisms (SNPs) amongst isolates from the same sample was used to measure diversity and most samples had a median of two SNPs (range: 0-251). NTS isolates that were within five SNPs to clinical UK isolates belonged to specific serovars: S. Enteritidis and S. Infantis (chicken), and S. I 4,[5],12:i- (pork and chicken). Most NTS isolates that were closely related to human-derived isolates were obtained from imported chicken, but further epidemiological data are required to assess definitively the probable source of the human cases. Continued WGS surveillance of Salmonella on retail food involving multiple isolates from each sample is necessary to capture the diversity of Salmonella and determine the relative importance of different sources of human disease.

Seroprevalence of non-typhoidal Salmonella disease and associated factors in children in Mukuru settlement in Nairobi County, Kenya.

Non-typhoidal Salmonella (NTS) infections remain a significant public health challenge especially in sub-Saharan Africa. NTS disease is endemic in Kenya and is associated with sporadic fatal outbreaks in several regions of the country with poor resource setting. Data is limited on background exposure of NTS in the population in endemic areas and the general immune status of the community most affected by NTS. The aim of the study was to determine the proportion of children exposed to Salmonella Enteritidis or Salmonella Typhimurium O antigen among the apparently healthy children and patients and the associated host and environmental factors among children attending selected healthcare facilities in Mukuru, Nairobi County, Kenya. A cross-sectional case-control study was conducted among patients and apparently healthy participants aged 0-5 years. Blood was collected and centrifuged to obtain serum. The serum was used to test for the presence of antibodies (IgA, IgG, IgM) against NTS using ELISA. A questionnaire was administered to obtain relevant demographic, socio-economic and healthcare utilization information. A total of 382 children were recruited into the study. The NTS seroprevalence was 12.6%. Among the apparently healthy participants, mean age of those exposed to NTS was 36 months and those not exposed was 27 months. Among patients, the mean age was 39 months and those not exposed was 30 months. The seroprevalence of NTS infection among the apparently healthy was significantly associated with cooking water, washing water and age of the child. Treating water using chlorine or boiling method was identified as being protective against contracting Salmonella Typhimurium/Enteritidis. Among the patients, the proportion of exposure was significantly associated with keeping animals and the chicken count. There is a high exposure to NTS among young children below five years of age and the population has developed immunity to the disease.

Increased antimicrobial resistance among non-typhoidal salmonella infections in international travellers returning to the Netherlands†.

Increased fluoroquinolone resistance in the two most common non-typhoidal Salmonella (NTS) serotypes among travellers returning to the Netherlands. Resistant Salmonella Enteritidis infections are most likely to be acquired abroad, specifically outside Europe. This study highlights the importance of travel history when patients with NTS infections require empiric antimicrobial treatment.

Antimicrobial-Resistant Nontyphoidal Salmonella Infection Following International Travel-United States, 2018-2019.

Antimicrobial resistance in nontyphoidal Salmonella (NTS) can limit treatment options. We assessed the contribution of international travel to antimicrobial-resistant NTS infections. We describe NTS infections that were reported to the Foodborne Diseases Active Surveillance Network during 2018-2019 and screened for genetic resistance determinants, including those conferring decreased susceptibility to first-line agents (ciprofloxacin, ceftriaxone, or azithromycin). We used multivariable logistic regression to assess the association between resistance and international travel during the 7 days before illness began. We estimated the contribution of international travel to resistance using population-attributable fractions, and we examined reported antimicrobial use. Among 9301 NTS infections, 1159 (12%) occurred after recent international travel. Predicted resistance to first-line antimicrobials was more likely following travel; the adjusted odds ratio varied by travel region and was highest after travel to Asia (adjusted odds ratio, 7.2 [95% confidence interval, 5.5-9.5]). Overall, 19% (95% confidence interval, 17%-22%) of predicted resistance to first-line antimicrobials was attributable to international travel. More travelers than nontravelers receiving ciprofloxacin or other fluoroquinolones had isolates with predicted resistance to fluoroquinolones (29% vs 9%, respectively; P < .01). International travel is a substantial risk factor for antimicrobial-resistant NTS infections. Understanding risks of resistant infection could help target prevention efforts.

Non-Typhoidal Salmonella Infections Among Children in Fuzhou, Fujian, China: A 10-Year Retrospective Review from 2012 to 2021.

Non-typhoidal salmonella (NTS) infection is a leading cause of acute gastroenteritis in children. Recently, NTS infections have increased, especially those associated with Salmonella Typhimurium, which has become a global problem because of its high level of drug resistance. Diseases caused by NTS serotypes vary considerably. We summarised NTS infections among children in Fuzhou, Fujian, China, from 2012 to 2021, and synthesised studies indicating the clinical symptoms, laboratory test results, and drug resistance associated with S. Typhimurium and non-S. Typhimurium to enhance the knowledge of these infections and improve their diagnoses and treatment. Between January 2012 and December 2021, 691 children with NTS infections confirmed by positive culture test results were recruited from Fujian Children's Hospital and Fujian Maternity and Child Health Hospital. Clinical demographic data of each case were collected from the electronic medical records and analysed. A total of 691 isolates were identified. The number of NTS infections increased significantly in 2017 and increased sharply during 2020 and 2021, especially S. Typhimurium greatly increased and was the dominant serotype (58.3%). S. Typhimurium infection was commonly occurred in children younger than 3 years and most of them were gastrointestinal infection, while non-S. Typhimurium more often observed in older children and associated with extra-intestinal infection. The rate of multidrug-resistant S. Typhimurium was significantly higher than that of non-S. Typhimurium, especially during the last 2 years of this study (2020 and 2021). S. Typhimurium was the dominant serotype and greatly increased among children in Fuzhou city. There are significant differences in clinical symptoms, laboratory test results, and drug resistance between S. Typhimurium and non-S. Typhimurium. More attention should be paid on S. Typhimurium. Long-term high-quality surveillance and control measures should be conducted to prevent salmonella infections and drug resistance.

NON-TYPHOIDAL SALMONELLA: A HOSPITAL BASED STUDY FROM SOUTH INDIA

Background &amp; objectives: The objective of this study was to evaluate the prevalence of Non-typhoidal Salmonella and to nd their antibiotic susceptibility pattern in a tertiary care hospital in South India. A signicant global health issue is the steadily rising percentage of Non-typhoidal Salmonella (NTS) infections in people. A descriptive study was conducted at Methods: a tertiary care teaching hospital in South India. Culture and sensitivity of stool samples of clinically suspected patients were done in the Microbiology laboratory from Sree Gokulam Medical College and Research Foundation. All samples were inoculated onto appropriate culture plates. Colonies suspected as Salmonella were identied by standard laboratory methods, initially by manual biochemical tests and by the VITEK-2 automated systems (bioMérieux) and nal serotyping by polyvalent antisera. 3 of the Salmonella isolates were sent to CMC, Vellore, India for serotyping. Antibiotic susceptibility tests were performed by Kirby Bauer's disc diffusion method on Mueller-Hinton agar and results were interpreted as per the CLSI guidelines (2022). Signed informed consent was obtained from all participants. Tests were performed in the clinical Microbiology Laboratory under the Department of Microbiology, Sree Gokulam Medical College and Research Foundation, Venjaramoodu, Trivandrum. Of the 244 mot Results: ion samples, Non-typhoidal Salmonella isolated were from 20 motion samples. The predominant serotype isolated was Salmonella Typhimurium (S. Typhimurium) in 16(80%) followed by Salmonella enteritidis in 3(15%) and Salmonella C2 in 1(5%) isolates. It was noticed by an increasing trend of resistance to Ampicillin, Chloramphenicol, Cephalosporins (Third generation) and Quinolones over this 18 month study. Based on this study, Conclusions: faecal prevalence of NTS (8.20%) were increasing among motion samples. Majority of isolates were from females (75%) with a mean age group belonging to Adults (46-60yrs). Except for Ampicillin and Cotrimoxazole, NTS isolates exhibited high rates of resistance to rst-line antibiotics. The gradual but consistent increase in resistance to Ampicillin, Fluoroquinolones, third generation Cephalosporins may restrict future treatment 1 options. Hence periodic monitoring of NTS infections, serotype distribution and antimicrobial resistance trend is recommended .

1367. Resistance to Ceftriaxone and Ciprofloxacin in Nontyphoidal Salmonella from Humans and Relatedness to Isolates from Animal Sources

Abstract Background Nontyphoidal Salmonella (NTS) is a leading cause of foodborne bacterial infections. Annually, ∼200,000 antimicrobial-resistant (AMR) NTS illnesses occur in the United States. NTS infections resistant to ceftriaxone and ciprofloxacin, drugs used for the treatment of severe infections, are a growing concern. Methods We identified patient NTS isolates submitted to the Pennsylvania Bureau of Laboratories by two hospitals from the same health system during 2018–2020. All were tested by broth microdilution for susceptibility to antibiotics tracked by the National Antimicrobial Resistance Monitoring System and analyzed by whole-genome sequencing. We identified resistance mechanisms and plasmids with ResFinder and PlasmidFinder, respectively, and compared each isolate in selected serotypes against the PulseNet database to identify genetic relatedness within ≤5 allele differences to non-human sequences uploaded during 2017–2021. Results Of 164 human NTS analyzed for susceptibility, 28 (17%) had decreased susceptibility to ciprofloxacin (DSC) [MIC ≥0.12 µg/mL] while 6 (3.7%) were ceftriaxone-resistant. AMR varied by serotype; 8 (50%) S. Infantis and 16 (42%) Enteritidis had DSC, representing 86% of all isolates with DSC (Figure). Six ceftriaxone-resistant isolates had genes that confer resistance to third-generation cephalosporins including blaCMY−2 in 1 Dublin and 2 Typhimurium and blaCTX-M-65 in 3 Infantis isolates. The 3 Infantis isolates also had a mutation in gyrA that results in DSC, plus a known transmissible plasmid IncFIB(pN55391) linked to multiple resistance genes. An Infantis isolate was related to a chicken meat isolate and a Hadar isolate was related to isolates from 3 animals and 3 meat sources. One Dublin isolate was related to 2 isolates from beef in Pennsylvania. Figure.Percent of antimicrobial resistance in nontyphoidal Salmonella (NTS) clinical isolates (n=164) submitted to public health authorities by two hospital systems in Pennsylvania, 2018–2020. Multidrug resistance (MDR) was defined as resistance to ≥3 of the 9 antimicrobial classes tested for NTS clinical isolates. Resistance to ceftriaxone (AXO), a third-generation cephalosporin preferred for treating severe infections in children, was over 5% and 19% in serotypes S. Typhimurium and S. Infantis, respectively. Half (8/16) of Infantis isolates and 42% (16/38) of Enteritidis isolates had decreased susceptibility to ciprofloxacin (DSC). Conclusion Ceftriaxone resistance and DSC in NTS from patients in Pennsylvania varied by serotype and some isolates harbored blaCMY−2 and blaCTX-M-65 genes. Dissemination of mechanisms that confer resistance to ceftriaxone and DSC is concerning as is the genetic relatedness of isolates from human and animal sources. Our study highlights the need for enhanced One Health AMR monitoring combined with a review of animal production and food processing practices. Disclosures All Authors: No reported disclosures.

2005. Direct Hospitalization Costs Associated with Resistant and Susceptible Salmonella and Shigella Infections in the United States — 2012–2019

Abstract Background Foodborne illnesses cost ∼$90 billion in the United States annually. Antibiotic-resistant infections may be more difficult to treat and can be associated with severe outcomes, leading to higher costs and longer length of stay (LOS). We described LOS and costs for hospital admissions for Salmonella and Shigella infections by resistance status. Methods We reviewed all inpatient admissions from ∼300 hospitals in the Premier Healthcare database during 2012–2019 and included records with culture-confirmed nontyphoidal Salmonella (NTS), typhoidal Salmonella (serotypes Typhi and Paratyphi A, B, and C), or Shigella. We classified infections as resistant if laboratory testing found resistance to ≥1 drug in the clinically important antibiotic categories (fluoroquinolones, macrolides, penicillins, folate pathway antagonists, or third-generation cephalosporins) or susceptible otherwise. We used the Wilcoxon rank sum test to assess difference in median LOS and cost of patient hospitalization for resistant vs. susceptible infections by pathogen type. Results Of 4,168 persons hospitalized, about half (n=2,129, 51%) were female; median age was 52 [IQR: 26‒68] years; 29% (n=1,217) of infections were resistant. For NTS infections, median LOS was 4 [IQR: 3‒7] days for resistant and 4 [IQR: 3‒6] (p=0.04) for susceptible; for typhoidal Salmonella, 6 [IQR: 5‒8] for resistant and 5 [IQR: 3‒8] for susceptible (p=0.15); and for Shigella, 3 [IQR: 2‒4] for both (p=0.09). Median costs were highest for typhoidal Salmonella ($12,577 resistant vs. $9,238 susceptible; p=0.21), followed by NTS ($7,179 vs $6,421, p=0.01) and Shigella ($4,975 vs $5,335; p=0.26). Conclusion Hospitalization costs were higher for patients with some resistant infections. Longer LOS may contribute to higher costs; however, it is not clear whether other pathogen or patient factors (e.g., comorbidities) also contributed. Additional data and adjusted analyses may provide insight into reasons for the cost difference. If resistant infections are shown to be the cause, our findings support that public health interventions to limit the spread of resistant infections could reduce costs. Disclosures All Authors: No reported disclosures.

Repetitive non-typhoidal Salmonella exposure is an environmental risk factor for colon cancer and tumor growth

During infection, Salmonella hijacks essential host signaling pathways. These molecular manipulations disrupt cellular integrity and may induce oncogenic transformation. Systemic S. Typhi infections are linked to gallbladder cancer, whereas severe non-typhoidal Salmonella (NTS) infections are associated with colon cancer (CC). These diagnosed infections, however, represent only a small fraction of all NTS infections as many infections are mild and go unnoticed. To assess the overall impact of NTS infections, we performed a retrospective serological study on NTS exposure in patients with CC. The magnitude of exposure to NTS, as measured by serum antibody titer, is significantly positively associated with CC. Repetitively infecting mice with low NTS exposure showed similar accelerated tumor growth to that observed after high NTS exposure. At the cellular level, NTS preferably infects (pre-)transformed cells, and each infection round exponentially increases the rate of transformed cells. Thus, repetitive exposure to NTS associates with CC risk and accelerates tumor growth.

Estimated Reduction in the Burden of Nontyphoidal Salmonella Illness in Canada Circa 2019.

Nontyphoidal Salmonella (NTS) is a leading cause of acute gastrointestinal illness in Canada, and reported cases have been on the rise since the early 2000s. To address this trend, agri-food industry partners and government have worked to identify and implement interventions, guided by the enhanced information provided by whole-genome sequencing, to reduce the incidence of NTS. A substantial reduction in the number of NTS cases reported occurred in 2019. Due to underreporting and underdiagnosis factors, the observed decrease in the number of reported cases represents a fraction of the true number of illnesses averted in the community. The objective of this study was to: (1) use burden of illness estimation methodologies to estimate the true number of NTS illnesses, hospitalizations, and deaths prevented, and (2) estimate the economic savings associated with the prevention of these cases. Compared with the previous 5 years, there were an estimated 25,821 fewer illnesses, 213 fewer hospitalizations, and 2 fewer deaths attributable to NTS in 2019. This corresponds to an estimated reduction of 26.9 million Canadian dollars in the economic burden of NTS. Although causality cannot be proven by this study, the findings are suggestive that the strategically implemented suite of public health actions, including genomic-based surveillance, policy changes, and interventions by the government and industry, were successful in reducing the economic and health burden of NTS infections in Canada.