Antimicrobial resistance and genetic relatedness of Salmonella serotypes isolated from food, asymptomatic carriers, and clinical cases in Shiyan, China.

Salmonella is a primary cause of foodborne diseases globally. Despite food contamination and clinical infections garnering substantial attention and research, asymptomatic Salmonella carriers, potential sources of infection, have been comparatively overlooked. In this study, we conducted a comparative analysis of serotype distribution, antimicrobial resistance phenotypes, and genetic profiles of archived Salmonella strains isolated from food (26), asymptomatic carriers (41), and clinical cases (47) in Shiyan City, China. Among the 114 Salmonella strains identified, representing 31 serotypes and 34 Sequence Types (STs), the most prevalent serovars included Typhimurium, Derby, Enteritidis, Thompson, and London, with the most predominant STs being ST11, ST40, ST26, ST34, and ST155. Antimicrobial resistance testing revealed that all strains were only sensitive to meropenem, with 74.6% showing antimicrobial resistance (AMR) and 53.5% demonstrating multidrug resistance (MDR). Strains resistant to five and six classes of antibiotics were the most common. Pearson's chi-square test showed no statistically significant difference in the occurrence of AMR (p = 0.105) or MDR (p = 0.326) among Salmonella isolates from the three sources. Our findings underscore associations and diversities among Salmonella strains isolated from food, asymptomatic carriers, and clinical patients, emphasizing the need for increased vigilance towards asymptomatic Salmonella carriers by authorities.

Prevalence, associated factors and antimicrobial susceptibility patterns of Salmonella and Shigella species among diarrheic under five children in Sultan Sheik Hassan Yabere referral Hospital, Jigjiga, Eastern Ethiopia.

BACKGROUND: Diarrhea caused by Salmonella and Shigella species are the leading cause of illness especially in developing countries. These infections are considered as the main public health problems in children, including Ethiopia. This study aimed to assess the prevalence, associated factors, and antimicrobial susceptibility patterns of Salmonella and Shigella species in Sheik Hassan Yabere Referral Hospital Jigjiga, Eastern Ethiopia from August 05 to November 15, 2022. METHOD: A cross-sectional study was conducted among 239 under-five children with diarrhea selected through a convenient sampling technique. A structured questionnaire was used to collect associated factors. A stool sample was collected and processed for the identification of Salmonella and Shigella species using MacConkey adar, Xylose Lysine Deoxycholate agar (Oxoid Ltd) and Biochemical tests. The antimicrobial susceptibility pattern of isolates was performed using the Kirby-Bauer disc diffusion technique. The data was entered into Epi-data version 4.6 and exported to the statistical package of social science version 22 for analysis. The association between outcome and independent variables was assessed using bivariate, multivariable, and chi-square and P-value < 0.05 was considered as statistical significance. RESULT: Overall prevalence of Salmonella and Shigella species was 6.3% (95% CI, 5.7-6.9%), of which 3.8% (95 CI, 3.2-4.4%) were Salmonella species and 2.5% (95% CI, 1.95-3%) were Shigella species. Unimproved water source (AOR = 5.08, 95% CI = 1.45, 17.25), open field (AOR = 2.3, 95% CI = 1.3, 5.03), rural residence (AOR = 1.8, 95% CI = 1.4, 7.5), Hand-washing practice (p = 0.001), and raw meat consumption (p = 0.002) were associated with occurrence of Salmonella and Shigella species. Salmonella and Shigella isolates were resistant to Ampicilin (100%). However, Salmonella isolates was sensitive to Norfloxacin (100%). About 22.2% and 16.7% of Salmonella and Shigella isolates were multi-drug resistant, respectively. CONCLUSION: Prevalence of Salmonella and Shigella species were lower than most studies done in Ethiopia. Hand-washing habit, water source type, Open field waste disposal habit, raw meat consumption and rural residence were associated with Salmonellosis and shigellosis. All isolated Salmonella were sensitive to norfloxacin. The evidence from this study underscores the need for improved water, sanitation and hygiene (WASH) system and the imperative to implement drug susceptibility tests for the treatment of Salmonella and Shigella infection.

Prevalence of multidrug resistance Salmonella species isolated from clinical specimens at University of Gondar comprehensive specialized hospital Northwest Ethiopia: A retrospective study.

BACKGROUND: Multidrug resistance Salmonellosis remains an important public health problem globally. The disease is among the leading causes of morbidity and mortality in developing countries, but there have been limited recent studies about the prevalence, antimicrobial resistance, and multidrug resistance patterns of Salmonella isolates from various clinical specimens. OBJECTIVE: Aimed to assess the prevalence, antimicrobial resistance, and multidrug resistance patterns of Salmonella isolates from clinical specimens at the University of Gondar Comprehensive Specialised Hospital, northwestern Ethiopia. METHOD: A retrospective hospital-based cross-sectional study was conducted to determine the prevalence, antimicrobial resistance, and multidrug resistance patterns of isolated from all clinical specimens at the University of Gondar Salmonella Comprehensive Specialised Hospital from June 1st, 2017 to June 3rd, 2022. A total of 26,154 data points were collected using a checklist of records of laboratory registration. Clinical specimens were collected, inoculated, and incubated for about a week with visual inspection for growth and gram staining. The isolates were grown on MacConkey agar and Xylose Lysine Deoxycholate agar. Pure colonies were identified with a conventional biochemical test, and those unidentified at the species level were further identified by the analytical profile index-20E. Then, antimicrobial susceptibility was determined by the Kirby-Bauer disc diffusion technique. The multidrug resistance Salmonella isolates was identified using the criteria set by Magiorakos. Finally, the data was cleaned and checked for completeness and then entered into SPSS version 26 for analysis. Then the results were displayed using tables and figures. RESULTS: Of the total 26,154 Salmonella suspected clinical samples, 41 (0.16%) Salmonella species were isolated. Most of the Salmonella isolates, 19 (46.3%), were in the age group of less than 18 years, followed by the age group of 19-44 years, 11 (26.8%). In this study, S. enterica subsp. arizonae accounts for the highest 21 (51%), followed by S. paratyphi A 9 (22%). Of the Salmonella isolates, S. typhi were highly resistant to ampicillin (100%), followed by tetracycline and trimethoprim-sulfamethoxazole, each accounting for 83.3%. Furthermore, S. paratyphi A was resistant to ampicillin (100%), tetracycline (88.9%), and chloramphenicol (88.9%). The overall multi-drug resistance prevalence was 22 (53.7%; 95% CI: 39.7-61). Accordingly, S. paratyphi A was 100% multidrug-resistant, followed by S. typhi (66.6%). CONCLUSION: A low prevalence of Salmonella species was observed in the past six years. Moreover, most S. typhi and S. paratyphi strains in the study area were found to be resistant to routinely recommended antibiotics like ciprofloxacin and ceftriaxone, compared to what was reported earlier. In addition, all isolates of S. paratyphi A and the majority of S. typhi were multidrug resistant. Therefore, health professionals should consider antimicrobial susceptibility tests and use antibiotics with caution for Salmonellosis management.

An inulin-based glycovesicle for pathogen-targeted drug delivery to ameliorate salmonellosis.

The gut microbiota plays a significant role in the pathogenesis and remission of inflammatory bowel disease. However, conventional antibiotic therapies may alter microbial ecology and lead to dysbiosis of the gut microbiome, which greatly limits therapeutic efficacy. To address this challenge, novel nanomicelles that couple inulin with levofloxacin via disulfide bonds for the treatment of salmonellosis were developed in this study. Owing to their H2S-responsiveness, the nanomicelles can target the inflamed colon and rapidly release levofloxacin to selectively fight against enteric pathogens. Moreover, the embedded inulin can serve as prebiotic fiber to increase the amount of Bifidobacteria and Lactobacilli in mice with salmonellosis, thus maintaining the intestinal mechanical barrier and regulating the balance of the intestinal flora. Therefore, multifunctional nanomicelles had a better curative effect than pure levofloxacin on ameliorating inflammation in vivo. The pathogen-targeted glycovesicle represents a promising drug delivery platform to maximize the efficacy of antibacterial drugs for the treatment of inflammatory bowel disease.

Enhancing colistin efficacy against Salmonella infections with a quinazoline-based dual therapeutic strategy.

Colistin remains one of the last-resort therapies for combating infections caused by multidrug-resistant (MDR) Enterobacterales, despite its adverse nephro- and neuro-toxic effects. This study elucidates the mechanism of action of a non-antibiotic 4-anilinoquinazoline-based compound that synergistically enhances the effectiveness of colistin against Salmonella enterica. The quinazoline sensitizes Salmonella by deactivating intrinsic, mutational, and transferable resistance mechanisms that enable Salmonella to counteract the antibiotic impact colistin, together with an induced disruption to the electrochemical balance of the bacterial membrane. The attenuation of colistin resistance via the combined treatment approach also proves efficacious against E. coli, Klebsiella, and Acinetobacter strains. The dual therapy reduces the mortality of Galleria mellonella larvae undergoing a systemic Salmonella infection when compared to individual drug treatments. Overall, our findings unveil the potential of the quinazoline-colistin combined therapy as an innovative strategy against MDR bacteria.

Salmonella enterica serotype Choleraesuis: a rare pathogen isolated from perianal abscess.

Infections with non-typhoidal salmonella (NTS) most commonly cause localised infections such as cutaneous abscesses in humans and are a leading source of foodborne illness. Here, we present a unique case of NTS Choleraesuis in a perianal abscess in an immunocompetent patient without any comorbidities.A woman in her late 40s was diagnosed with a perianal abscess with an unknown origin of infection. The patient has undergone an incision and drainage. Her pus culture and sensitivity report yielded Salmonella enterica serotype Choleraesuis. Then, the patient recovered after treatment with intravenous antibiotics and supportive treatment.We present an unusual case of S. enterica serotype Choleraesuis, which is rarely reported as a causative agent of perianal abscess in India. This case has been reported for its rarity in India.

Cananga oil inhibits Salmonella infection by mediating the homeostasis of purine metabolism and the TCA cycle.

ETHNOPHARMACOLOGY RELEVANCE: Cananga oil (CO) is derived from the flowers of the traditional medicinal plant, the ylang-ylang tree. As a traditional antidepressant, CO is commonly utilized in the treatment of various mental disorders including depression, anxiety, and autism. It is also recognized as an efficient antibacterial insecticide, and has been traditionally utilized to combat malaria and acute inflammatory responses resulting from bacterial infections both in vitro and in vivo. AIM OF THE STUDY: The objective of this study is to comprehensively investigate the anti-Salmonella activity and mechanism of CO both in vitro and in vivo, with the expectation of providing feasible strategies for exploring new antimicrobial strategies and developing novel drugs. METHODS: The in vitro antibacterial activity of CO was comprehensively analyzed by measuring MIC, MBC, growth curve, time-killing curve, surface motility, biofilm, and Live/dead bacterial staining. The analysis of the chemistry and active ingredients of CO was conducted using GC-MS. To examine the influence of CO on the membrane homeostasis of Salmonella, we conducted utilizing diverse techniques, including ANS, PI, NPN, ONPG, BCECF-AM, DiSC3(5), and scanning electron microscopy (SEM) analysis. In addition, the antibacterial mechanism of CO was analyzed and validated through metabolomics analysis. Finally, a mouse infection model of Salmonella typhimurium was established to evaluate the toxic side effects and therapeutic effects of CO. RESULTS: The antibacterial effect of CO is the result of the combined action of the main chemical components within its six (palmitic acid, α-linolenic acid, stearic acid, benzyl benzoate, benzyl acetate, and myristic acid). Furthermore, CO disrupts the balance of purine metabolism and the tricarboxylic acid cycle (TCA cycle) in Salmonella, interfering with redox processes. This leads to energy metabolic disorders and oxidative stress damage within the bacteria, resulting in bacterial shock, enhanced membrane damage, and ultimately bacterial death. It is worth emphasizing that CO exerts an effective protective influence on Salmonella infection in vivo within a non-toxic concentration range. CONCLUSION: The outcomes indicate that CO displays remarkable anti-Salmonella activity both in vitro and in vivo. It triggers bacterial death by disrupting the balance of purine metabolism and the TCA cycle, interfering with the redox process, making it a promising anti-Salmonella medication.

Fisetin inhibits Salmonella Typhimurium type III secretion system regulator HilD and reduces pathology in vivo.

IMPORTANCE: Salmonella spp. remains a major worldwide health concern that causes significant morbidity and mortality in both humans and animals. The spread of antimicrobial resistant strains has declined the efficacy of conventional chemotherapy. Thus, novel anti-infection drugs or strategies are needed. Anti-virulence strategy represents one of the promising means for the treatment of bacterial infections. In this study, we found that the natural compound fisetin could inhibit Salmonella invasion of host cells by targeting SPI-1 regulation. Fisetin treatment impaired the interaction of the regulatory protein HilD with the promoters of its target genes, thereby suppressing the expression of T3SS-1 effectors as well as structural proteins. Moreover, fisetin treatment could reduce pathology in the Salmonella murine infection model. Collectively, our results suggest that fisetin may serve as a promising lead compound for the development of anti-Salmonella drugs.

Defying the odds: Determinants of the antimicrobial response of Salmonella Typhi and their interplay.

Salmonella Typhi, the invasive serovar of S. enterica subspecies enterica, causes typhoid fever in healthy human hosts. The emergence of antibiotic-resistant strains has consistently challenged the successful treatment of typhoid fever with conventional antibiotics. Antimicrobial resistance (AMR) in Salmonella is acquired either by mutations in the genomic DNA or by acquiring extrachromosomal DNA via horizontal gene transfer. In addition, Salmonella can form a subpopulation of antibiotic persistent (AP) cells that can survive at high concentrations of antibiotics. These have reduced the effectiveness of the first and second lines of antibiotics used to treat Salmonella infection. The recurrent and chronic carriage of S. Typhi in human hosts further complicates the treatment process, as a remarkable shift in the immune response from pro-inflammatory Th1 to anti-inflammatory Th2 is observed. Recent studies have also highlighted the overlap between AP, persistent infection (PI) and AMR. These incidents have revealed several areas of research. In this review, we have put forward a timeline for the evolution of antibiotic resistance in Salmonella and discussed the different mechanisms of the same availed by the pathogen at the genotypic and phenotypic levels. Further, we have presented a detailed discussion on Salmonella antibiotic persistence (AP), PI, the host and bacterial virulence factors that can influence PI, and how both AP and PI can lead to AMR.

Clinical Outcomes of Patients With Nontyphoidal Salmonella Infections by Isolate Resistance-Foodborne Diseases Active Surveillance Network, 10 US Sites, 2004-2018.

BACKGROUND: Nontyphoidal Salmonella causes an estimated 1.35 million US infections annually. Antimicrobial-resistant strains are a serious public health threat. We examined the association between resistance and the clinical outcomes of hospitalization, length-of-stay ≥3 days, and death. METHODS: We linked epidemiologic data from the Foodborne Diseases Active Surveillance Network with antimicrobial resistance data from the National Antimicrobial Resistance Monitoring System (NARMS) for nontyphoidal Salmonella infections from 2004 to 2018. We defined any resistance as resistance to ≥1 antimicrobial and clinical resistance as resistance to ampicillin, azithromycin, ceftriaxone, ciprofloxacin, or trimethoprim-sulfamethoxazole (for the subset of isolates tested for all 5 agents). We compared outcomes before and after adjusting for age, state, race/ethnicity, international travel, outbreak association, and isolate serotype and source. RESULTS: Twenty percent of isolates (1105/5549) had any resistance, and 16% (469/2969) had clinical resistance. Persons whose isolates had any resistance were more likely to be hospitalized (31% vs 28%, P = .01) or have length-of-stay ≥3 days (20% vs 16%, P = .01). Deaths were rare but more common among those with any than no resistance (1.0% vs 0.4%, P = .01). Outcomes for patients whose isolates had clinical resistance did not differ significantly from those with no resistance. After adjustment, any resistance (adjusted odds ratio 1.23, 95% confidence interval 1.04-1.46) remained significantly associated with hospitalization. CONCLUSIONS: We observed a significant association between nontyphoidal Salmonella infections caused by resistant pathogens and likelihood of hospitalization. Clinical resistance was not associated with poorer outcomes, suggesting that factors other than treatment failure (eg, strain virulence, strain source, host factors) may be important.

Chest wall abscess and costochondritis due to Salmonella enterica serotype Choleraesuis: a case report.

BACKGROUND: Salmonella enterica serotype Choleraesuis infections usually cause self-limited gastrointestinal diseases. Extra-abdominal infections are often secondary to bacteremia in immunocompromised individuals and are relatively rare in immunocompetent hosts. CASE PRESENTATION: A 65-year-old Caucasian female initially presented to the thoracic surgery clinic due to a poorly healing wound on her chest. Her condition started after a mechanical fall hitting her chest with interval development of a tender lump that later spontaneously drained. A chest computed tomography scan with intravenous contrast demonstrated an abnormal infiltration with small foci of fluid and air consistent with a small abscess anterior to the left seventh costal cartilage. Aspirate culture of the abscess grew S. enterica serotype Choleraesuis susceptible to ampicillin and trimethoprim/sulfamethoxazole. The patient had no prior history of signs or symptoms of gastrointestinal infection. Blood cultures were negative. With a background of penicillin allergy, she was treated with trimethoprim/sulfamethoxazole, and later with ceftriaxone due to persistent drainage of the wound. Follow-up chest computed tomography scan with intravenous (IV) contrast showed continued abnormal findings previously seen in the computed tomography scan with the appearance of a sinus tract. The patient subsequently underwent surgical debridement and partial resection of the left seventh costochondral cartilage and excision of the fistula. She had an uneventful recovery and complete resolution of her condition. CONCLUSION: We report a rare case of chest wall abscess with associated costochondritis due to S. enterica serotype Choleraesuis in a patient with no evidence of immunodeficiency nor history of bacteremia. Extraintestinal infections due to Salmonella without documented bacteremia have been previously reported in the literature. History of local trauma to the affected area might contribute to the seeding of infection. Diagnosis is often accomplished by clinical evaluation and culture of the affected area. Treatment often involves targeted antibiotic therapy but may require surgical intervention to achieve source control and cure.

Self-assembly of H2S-responsive nanoprodrugs based on natural rhein and geraniol for targeted therapy against Salmonella Typhimurium.

Salmonellosis is a globally extensive food-borne disease, which threatens public health and results in huge economic losses in the world annually. The rising prevalence of antibiotic resistance in Salmonella poses a significant global concern, emphasizing an imperative to identify novel therapeutic agents or methodologies to effectively combat this predicament. In this study, self-assembly hydrogen sulfide (H2S)-responsive nanoprodrugs were fabricated with poly(α-lipoic acid)-polyethylene glycol grafted rhein and geraniol (PPRG), self-assembled into core-shell nanoparticles via electrostatic, hydrophilic and hydrophobic interactions, with hydrophilic exterior and hydrophobic interior. The rhein and geraniol are released from self-assembly nanoprodrugs PPRG in response to Salmonella infection, which is known to produce hydrogen sulfide (H2S). PPRG demonstrated stronger antibacterial activity against Salmonella compared with rhein or geraniol alone in vitro and in vivo. Additionally, PPRG was also able to suppress the inflammation and modulate gut microbiota homeostasis. In conclusion, the as-prepared self-assembly nanoprodrug sheds new light on the design of natural product active ingredients and provides new ideas for exploring targeted therapies for specific Enteropathogens. Graphical  illustration for construction of self-assembly nanoprodrugs PPRG and its antibacterial and anti-inflammatory activities on experimental Salmonella infection in mice.

Typhoid spondylodiscitis of the cervical spine.

Spinal infection comprises pyogenic and non-pyogenic spondylodiscitis. This condition may manifest with non-specific clinical symptoms, elevated infective parameters and imaging findings that are difficult to distinguish. The cornerstone of a definitive diagnosis and subsequent successful treatment lies in tissue analysis through culture and histopathological studies. In this context, we present a case of Salmonella pyogenic spondylodiscitis affecting the C5/C6 vertebrae, complicated by Salmonella bacteraemia and characterised by mechanical neck pain that curtails daily activities and overall functioning, although without neurological deficits. The uniqueness of this case stems from its occurrence in an immunocompetent individual from a non-endemic area, with no identifiable sources of Salmonella infection or preceding gastrointestinal symptoms.

Salmonella Vaccine Study in Oxford (SALVO) trial: protocol for an observer-participant blind randomised placebo-controlled trial of the iNTS-GMMA vaccine within a European cohort.

INTRODUCTION: Invasive non-typhoidal Salmonellosis (iNTS) is mainly caused by Salmonella enterica serovars Typhimurium and Enteritidis and is estimated to result in 77 500 deaths per year, disproportionately affecting children under 5 years of age in sub-Saharan Africa. Invasive non-typhoidal Salmonellae serovars are increasingly acquiring resistance to first-line antibiotics, thus an effective vaccine would be a valuable tool in reducing morbidity and mortality from infection. While NTS livestock vaccines are in wide use, no licensed vaccines exist for use in humans. Here, a first-in-human study of a novel vaccine (iNTS-GMMA) containing S. Typhimurium and S. Enteritidis Generalised Modules for Membrane Antigens (GMMA) outer membrane vesicles is presented. METHOD AND ANALYSIS: The Salmonella Vaccine Study in Oxford is a randomised placebo-controlled participant-observer blind phase I study of the iNTS-GMMA vaccine. Healthy adult volunteers will be randomised to receive three intramuscular injections of the iNTS-GMMA vaccine, containing equal quantities of S. Typhimurium and S. Enteritidis GMMA particles adsorbed on Alhydrogel, or an Alhydrogel placebo at 0, 2 and 6 months. Participants will be sequentially enrolled into three groups: group 1, 1:1 randomisation to low dose iNTS-GMMA vaccine or placebo; group 2, 1:1 randomisation to full dose iNTS-GMMA vaccine or placebo; group 3, 2:1 randomisation to full dose or lower dose (dependant on DSMC reviews of groups 1 and 2) iNTS-GMMA vaccine or placebo.The primary objective is safety and tolerability of the vaccine. The secondary objective is immunogenicity as measured by O-antigen based ELISA. Further exploratory objectives will characterise the expanded human immune profile. ETHICS AND DISSEMINATION: Ethical approval for this study has been obtained from the South Central-Oxford A Research Ethics Committee (Ethics REF:22/SC/0059). Appropriate documentation and regulatory approvals have been acquired. Results will be disseminated via peer-reviewed articles and conferences. TRIAL REGISTRATION NUMBER: EudraCT Number: 2020-000510-14.

Anti-Proteolytic Peptide R7I Protects the Intestinal Barrier and Alleviates Fatty Acid Malabsorption in Salmonella typhimurium-Infected Mice.

With a wide range of hosts, environmental adaptation, and antibiotic resistance, Salmonella typhimurium is one of the most common causes of food poisoning in the world. Infection with Salmonella typhimurium not only results in intestinal inflammation but also damages the intestinal barrier and interferes with the host's ability to absorb nutrients. It is imperative to find alternatives to antibiotics for eradicating bacteria, reducing intestinal damage, and reestablishing nutrient absorption, especially given that antibiotics are currently prohibited. This research aims to understand the protective role of anti-proteolytic peptide R7I on the gut in the setting of Salmonella typhimurium infection and its impact on nutritional absorption, maybe offering an alternative to antibiotics for bacterial killing. The findings demonstrated that R7I reduced the production of inflammatory factors, including IL-6, TNF-α, and L-1ß in the jejunum and decreased the expression of genes like TLR4 and NF-κB in the jejunum (p < 0.05). R7I enhanced antioxidant capacity and preserved the antioxidant/pro-oxidant balance in the jejunum (p < 0.05). R7I also normalized intestinal shape and restored tight junction protein expression. Fatty acid binding protein 2 (FABP2) and fatty acid transport protein 4 (FATP4) expression in the jejunum was restored by R7I. In addition, serum-free fatty acids and lipid metabolites were significantly higher in the R7I group than in the control group (p < 0.05). Overall, the anti-enzyme peptide R7I maintained the healthy state of the intestine and alleviated the abnormal fatty acid absorption caused by bacterial infection.

Clinical and microbiological characterization of Salmonella spp. isolates from patients treated in a university hospital in South America between 2012-2021: a cohort study.

BACKGROUND: Salmonellosis is a major cause of morbidity and mortality and one of the most frequent etiologies of diarrhea in the world. Mortality due to Salmonellosis in Latin America still poorly understood, and there is a lack of studies that evaluate resistance and clinical manifestations. The aims of this study were to characterize patients infected with Salmonella spp. seen in a university hospital in Colombia between 2012 and 2021, to evaluate trends in antibiotic resistance and to determine the proportion of overall mortality and related factors. METHODS: Retrospective observational study. All patients with microbiological diagnosis of Salmonella spp. were included. The sociodemographic, clinical and microbiological characteristics were described, and the proportion of antibiotic resistant isolates per year was estimated. The prevalence of mortality according to age groups was calculated. Log binomial regression models were used to establish factors associated with mortality. RESULTS: Five hundred twenty-two patients were analyzed. Salmonellosis accounted for 0.01% of all medical consultations. The median age was 16 years old. The most common clinical presentation was gastroenteric syndrome (77.1%) and symptoms included diarrhea (79.1%), fever (66.7%), abdominal pain (39.6%) and vomiting (35.2%). Of the Salmonella spp. isolates, 78.2% were not classified, 19.1% corresponded to non-typhoidal Salmonella and 2.7% to Salmonella typhi. Mortality occurs in 4.02% of the patients and was higher in patients with hematologic malignancy (11.6%). When analyzing by age group, the proportion of deaths was 2.8% in patients aged 15 years or younger, while in those older than 15 years it was 5.4%. Factors associated to mortality where bacteremia (aPR = 3.41 CI95%: 1.08-10.76) and to require treatment in the ICU (aPR = 8.13 CI95%: 1.82-37.76). In the last 10 years there has been a steady increase in resistance rates to ciprofloxacin, ampicillin, ampicillin/sulbactam and ceftriaxone, reaching rates above 60% in recent years. CONCLUSIONS: Despite improved availability of antibiotics for the treatment of salmonellosis in the past decades, mortality due to salmonellosis continues occurring in children and adults, mainly in patients with hematological malignancies and bacteremia. Antibiotic resistance rates have increased significantly over the last 10 years. Public health strategies for the control of this disease should be strengthened, especially in vulnerable populations.

Anti-infective treatment of gastro-intestinal tract infections in children.

Gastroenteritis is most often viral in origin and Rotavirus and Norovirus most frequently implicated in young children. Stool-based multiplex Polymerase Chain Reaction (PCR) can detect bacteria, viruses or parasites that may or may not be responsible for gastroenteritis (colonization). While the etiological profile of these digestive infections has greatly benefited from PCR, in the absence of underlying pathologies the presence of potential pathogens does not justify anti-infectious treatment. Indeed, very few bacterial causes require antibiotic treatment, apart from shigellosis, severe forms of salmonellosis and a few Campylobacter sp. infections. The development of antibiotic resistance in Salmonella sp., Shigella sp. and Campylobacter sp. is a cause for concern worldwide, limiting therapeutic options. The antibiotics proposed in this guide are in line with the joint recommendations of the European Society of Pediatric Infectious Diseases and the European Society of Pediatric Gastroenterology and Nutrition. Azithromycin is preferentially used to treat infections with Shigella sp. or Campylobacter sp. Ceftriaxone and ciprofloxacin are recommended for salmonellosis requiring antibiotic therapy. Empirical treatments without bacterial identification are not indicated except in cases of severe sepsis or in subjects at risk (e.g., sickle-cell disease). Metronidazole should be prescribed only for acute intestinal amebiasis after microbiological confirmation.

Salmonella meningitis in a young child from Pakistan: a case report.

BACKGROUND: Salmonella meningitis is a rare but serious complication of Salmonella infection, primarily affecting infants, children, and immunocompromised individuals. CASE PRESENTATION: We present a case of a two-and-a-half-year-old Asian boy who developed Salmonella meningitis along with pneumonia and respiratory failure. Initially, he experienced symptoms of loose motions, fever, and irritability, which progressed to neck stiffness and brisk reflexes. Cerebrospinal fluid (CSF) analysis confirmed Salmonella typhi in the CSF. Due to the worsening condition, the patient was admitted to the intensive care unit, intubated, and switched to meropenem as the antibiotic of choice after an initial empiric therapy with ceftriaxone and vancomycin. With appropriate treatment, the patient showed significant improvement, including resolution of fever and respiratory symptoms. CONCLUSION: Management of Salmonella meningitis is often challenging primarily because of the fact that the empiric therapy for meningitis may not always provide coverage to the multi-drug resistant Salmonella species found in South Asia. Prompt administration of appropriate antibiotics based on sensitivity testing is crucial for successful management. This case emphasizes the importance of early recognition and effective management of this uncommon yet severe complication of Salmonella infection.

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.

[Clinical features and antimicrobial resistance of invasive non-typhoid Salmonella infection in children at Xiamen].

Objective: To investigate the clinical characteristics, serogroups and antimicrobial resistance of invasive non-typhoid Salmonella infection in children at Xiamen. Methods: Retrospective cohort study. The clinical manifestations, treatment, prognosis, serogroups and antimicrobial resistance of 29 hospitalized children with invasive non-typhoid Salmonella infection confirmed by blood, cerebrospinal fluid, bone marrow and other sterile body fluids or deep pus culture at the Department of Infectious Diseases, the Department of Orthopedics and the Department of General Surgery in Xiamen Children's Hospital from January 2016 to December 2021 were analyzed. According to the clinical diagnosis criteria, the patients were divided into sepsis group and non-sepsis group (bacteremia and local suppurative infection). The inflammatory markers, serogroups distribution and drug resistance were compared between the two groups. Comparison between groups using Mann-Whitney U test and χ2 test. Results: Among the 29 cases, there were 17 males and 12 females, with an onset age of 14 (9, 25) months, and 10 cases (34%) of patients were younger than 1 year old, 15 cases (52%) under 1 to 3 years old, and 4 cases (14%) greater than or equal 3 years old. The onset time of 25 cases (86%) was from April to September. The diseases included 19 cases (66%) septicemia (2 of which were combined with suppurative meningitis), 10 cases (34%) non-sepsis group, including 7 cases bacteremia and 3 cases local suppurative infection (2 cases of osteomyelitis, 1 case of appendicitis with peritonitis). The clinical manifestations were fever in 29 cases (100%), diarrhea and abdominal pain in 18 cases (62%), cough and runny nose in 10 cases (34%). Eighteen cases (62%) were cured and 11 cases (38%) were improved by effective antibiotics treatment. C-reactive protein in sepsis group was significantly higher than that in non-sepsis group (25.2 (16.1, 56.4) vs. 3.4 (0.5, 7.5) mg/L, Z=-3.81, P<0.001).The serogroups of C, B and E were the most prevalent among non-typhoid Salmonella isolates, accounting for 10 cases (34%), 9 cases (31%) and 7 cases (24%) respectively. Antibacterial drug sensitivity test showed that the sensitivity rates of imipenem, ertapenem and piperaciratazobactam were all 100% (31/31), those of ceftazidime, ceftriaxone, and cefepime were 94% (29/31), 94% (29/31) and 97% (30/31) respectively. The drug resistance rates of ampicillin, ampicillin-sulbactam and trimethoprim-sulfamethoxazole were 51% (16/31), 48% (15/31) and 48% (15/31) respectively, those of cefazolin, cefotetan, tobramycin, gentamicin and amikacinwere all 100% (31/31). There were no significant differences in the drug resistance rates of ceftazidime, ceftriaxone, aztreonam, ampicillin-sulbactam, ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin between the sepsis group and the non-sepsis group (χ2=0.31,0.31,0.00,0.02,0.02,0.02,0.26, all P>0.05). Conclusions: Invasive non-typhoid Salmonella infection in children at Xiamen mainly occurred in infants younger than 3 years old.The main clinical manifestations are fever, abdominal pain and diarrhea. C-reactive protein can be served as the laboratory indicators for indicating sepsis. The third generation of cephalosporins is recommended as the first choice for treatment.