OBJECTIVES: To investigate the clinical characteristics and drug resistance profile of invasive non-typhoidal Salmonella (NTS) enteritis in children in Chengdu, China, providing a reference for rational drug use and empirical treatment in clinical practice. METHODS: A retrospective analysis was conducted on the clinical data of 130 children with invasive bacterial enteritis due to NTS identified by fecal bacterial culture and the results of drug sensitivity tests for NTS in Chengdu from January 2022 to December 2023. RESULTS: NTS infections were mainly observed from April to September (113 cases, 86.9%), with a peak in August (36 cases, 27.7%). Children aged <36 months accounted for 86.2% (112/130) of all cases, and the main symptoms were diarrhea (130 cases, 100%), fever (123 cases, 94.6%), and hematochezia (112 cases, 86.2%). The 130 NTS isolates exhibited a sensitivity rate of 64.6% to ceftriaxone and 63.8% to cefotaxime, and a sensitivity rate of >90.0% to piperacillin-tazobactam and nitrofurantoin (nitrofurans). The detection rate of multidrug-resistant strains was 48.5% (63/130), and the clinical efficacy of third-generation cephalosporins used in 38 patients (29.2%) was inconsistent with the results of drug sensitivity tests. CONCLUSIONS The peak of invasive NTS enteritis in children aged 0-6 years occurs in August in the Chengdu area, with a relatively high incidence rate in children aged <36 months. The situation of drug resistance is severe for NTS, and piperacillin-tazobactam may be an effective option for treating multidrug-resistant NTS infections in children, while nitrofuran antibiotics might be used to treat such infections.
Humans ; Infant ; Child, Preschool ; Enteritis/microbiology* ; Retrospective Studies ; Male ; Salmonella Infections/microbiology* ; Female ; Child ; Salmonella/drug effects* ; Infant, Newborn ; Microbial Sensitivity Tests ; Anti-Bacterial Agents/therapeutic use*

Salmonellosis represents a global epidemic, and the emergence of extensively drug-resistant (XDR) Salmonella and its sustained transmission worldwide constitutes a significant public health concern. Flagellum-mediated motility serves as a crucial virulence trait of Salmonella that guides the pathogen toward the epithelial surface, enhancing gut colonization. Artemisia argyit essential oil, a traditional herb extract, demonstrates efficacy in treating inflammation-related symptoms and diseases; however, its effects on flagellum assembly and expression mechanisms in anti-Salmonella activity remain inadequately explored. This study aimed to elucidate the mechanism by which Artemisia argyit essential oil addresses Salmonella infections. Network pharmacological analysis revealed that Traditional Chinese Medicine (TCM) Artemisia argyit exhibited anti-Salmonella infection potential and inhibited flagellum-dependent motility. The application of Artemisia argyit essential oil induced notable motility defects through the downregulation of flagellar and fimbriae expression. Moreover, it significantly reduced Salmonella-infected cell damage by interfering with flagellum-mediated Salmonella colonization. In vivo studies demonstrated that Artemisia argyit essential oil administration effectively alleviated Salmonella infection symptoms by reducing bacterial loads, inhibiting interleukin-1 beta (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α) production, and diminishing pathological injury. Gas chromatography-mass spectrometry (GC-MS) analysis identified forty-three compounds in Artemisia argyit essential oil, with their corresponding targets and active ingredients predicted. Investigation of an in vivo model of Salmonella infection using the active ingredient demonstrated that alpha-cedrene ameliorated Salmonella infection. These findings suggest the potential application of Artemisia argyit essential oil in controlling Salmonella, the predominant food-borne pathogen.
Artemisia/chemistry* ; Oils, Volatile/chemistry* ; Animals ; Flagella/drug effects* ; Salmonella Infections/microbiology* ; Humans ; Mice ; Anti-Bacterial Agents/pharmacology* ; Salmonella/pathogenicity*

OBJECTIVE: Our study aimed to conduct genomic characterization of Salmonella strains carrying the bla _NDM-1 gene in the intestinal tract of healthy individuals. The objectives were to underscore the importance of genomic surveillance for drug resistance in both commensal and pathogenic bacteria among healthy populations, and to establish protocols for regulating drug resistance plasmids based on the completion of a comprehensive map of drug resistance plasmid genomes. METHODS: We performed antimicrobial susceptibility testing and employed second- and third-generation sequencing techniques to analyze Salmonella strains harboring the bla _NDM-1 gene, to surveil drug-resistant bacteria in the intestines of healthy subjects. Sequence comparison was conducted using both core- and pan-genome approaches. Concurrently, conjugation experiments were carried out to assess the efficiency of plasmid transfer. RESULTS: We isolated a carbapenem-resistant Salmonella enterica serovar Typhimurium strain from a healthy food worker in China. This strain harbored an IncHI2/IncHI2A plasmid carrying bla _NDM-1 along with multiple antibiotic resistance genes (ARGs). Our findings highlight the potential for asymptomatic carriers to facilitate the transmission of ARGs. Pan-genomic analysis revealed that bla _NDM-1-positive plasmids could traverse bacterial species barriers, facilitating cross-host transmission. CONCLUSION This study marks the first detection of bla _NDM-1 in Salmonella strains isolated from healthy individuals. We underscore the risk associated with the transmission of conjugative hybrid plasmids carrying bla _NDM-1, which have the potential to be harbored and transmitted among healthy individuals. Enhanced surveillance of drug-resistant pathogens and plasmids in the intestinal microbiota of healthy individuals could provide insights into the risk of ARG transmission and pathways for population-wide dissemination via ARG transfer factors.
beta-Lactamases/genetics* ; Plasmids/genetics* ; Humans ; Anti-Bacterial Agents/pharmacology* ; China ; Microbial Sensitivity Tests ; Salmonella typhimurium/isolation & purification* ; Salmonella/isolation & purification* ; Salmonella Infections/microbiology*

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.
Infant ; Male ; Female ; Child ; Humans ; Child, Preschool ; Anti-Bacterial Agents/therapeutic use* ; Ceftriaxone/therapeutic use* ; Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use* ; Ceftazidime/therapeutic use* ; Retrospective Studies ; C-Reactive Protein ; Drug Resistance, Bacterial ; Salmonella Infections/microbiology* ; Ampicillin/therapeutic use* ; Salmonella ; Diarrhea/drug therapy* ; Bacteremia ; Abdominal Pain ; Microbial Sensitivity Tests

Objective: To understand the circulation, drug resistance and molecular characteristics of Salmonella1, 4, [5], 12: i:- in human in Guangdong province. Methods:Salmonella1, 4, [5], 12: i:- isolated from diarrhea patients in Guangdong during 2007-2016 were detected for drug resistance, genes and PFGE characteristics. Results: A total of 2 960 strains Salmonella1, 4, [5], 12: i: - were isolated from human diarrhea cases during this period. The positive rates of the isolation increased year by year. The male to female ratio of the infection cases was 1.58∶1, and the infection mainly occurred in infants and young children. Except imipenem, Salmonella1, 4, [5], 12: i: - was resistant to other 17 antibiotics to some extent. The drug resistant rates to ceftazidime, cefotaxime and ciprofloxacin increased from 2011 to 2016. Multi-drug resistance was serious, for example, the multi-drug resistant strains with ASSuT accounted for 70.62% (435/616) and the multi-drug resistant strains with ACSuGSTTm accounted for 27.11% (167/616). The lack of fljA, fljB and hin genes, as well as the retaining of iroB, STM2740, STM2757 genes, resulted in the unable expression of FljBenx gene with 8 different defection profiles. There were 934 different PFGE patterns observed in 2 347 strains, which displayed a relatively large fingerprint polymorphism. The major PFGE pattern was JPXX01. GD0226, which was found in 97 strains, accounting for 4.13% (97/2 347). The PFGE patterns in 168 Salmonella1, 4, [5], 12: i: - strains were consistent with that of Salmonella typhimurium. Conclusions:Salmonella1,4,[5], 12: i: - strains has become the major serotype of Salmonella that cause diarrhea in human in Guangdong. The multi-drug resistance of Salmonella1,4, [5], 12: i: - was serious, and since the defection of fljA, fljB and hin genes, the expression of FljBenx protein failed. The PFGE results were diverse, which displayed polymorphism in inheritance.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents/pharmacology* ; Child ; Child, Preschool ; China/epidemiology* ; Diarrhea/microbiology* ; Drug Resistance, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Salmonella Infections/prevention & control* ; Salmonella enterica/isolation & purification* ; Salmonella typhimurium ; Serogroup ; Serotyping ; Young Adult

Objective: To understand the etiological characteristics of bacterial diarrhea in different areas, including large cities, mid-sized/small cities and rural area, in China. Methods: A cross-sectional surveillance was conducted in 17 provinces of China from 2010 to 2014. The acute diarrhea outpatients were selected from clinics or hospitals in large cities, mid-sized/small cities, including rural-urban fringe zones, and rural areas. The demographical and clinical characteristics of the patients were collected by using questionnaire, and stool samples were taken from them for laboratory detection of 17 kinds of bacteria. The differences in pathogen positive rates (PPR) and pathogen spectrum across the cases from three-type areas were compared. The different infection risk in different cases were analyzed with unconditional logistic regression model. Results: In our study, we enrolled 9 253 cases from large cities, 5 138 cases from rural areas and 13 683 cases from midsized/small cites. The pathogen with largest differences in infection rate across the three-type areas was Shigella (S.) flexneri (rural area: 5.81%, mid-sized/small city: 2.78%, large city: 0.46%), followed by Aeromonas (A.) hydrophila (rural area: 2.14%, mid-sized/small city: 0.96%, large city: 0.48%). Compared with cases in large cities, the cases in mid-sized/small cities and rural areas had higher infection risks for S. flexneri (mid-sized/small city: OR=6.481, 95%CI: 4.666-9.002, rural area: OR=11.304, 95%CI: 8.018-15.938) and A. hydrophila (mid-sized/small city: OR=1.992, 95%CI:1.401-2.832, rural area: OR=4.083, 95%CI: 2.833-5.884). The constituent ratio of diarrheagenic Escherichia coli and Salmonella increased with the urbanization development, while the ratios of Shigella and A. hydrophila had an opposite trend. S. sonnei (60.00%) was the predominant serogroup of Shigella in urban infections, while S. flexneri (77.37%) was the predominant serogroup in rural infections. Conclusion: The differences in pathogen spectrum of bacterial diarrhea were obvious across large cities, mid-sized/small cities and rural areas in China, especially the differences in the infection rates of S. flexneri and A. hydrophila.
Adolescent ; Adult ; Bacterial Infections/microbiology* ; Child ; China/epidemiology* ; Cross-Sectional Studies ; Diarrhea/microbiology* ; Dysentery/epidemiology* ; Escherichia coli/pathogenicity* ; Feces/virology* ; Female ; Humans ; Male ; Middle Aged ; Prevalence ; Rural Population ; Salmonella/pathogenicity* ; Shigella/pathogenicity* ; Suburban Population ; Urban Population

OBJECTIVETo investigate the antimicrobial resistance status and pulsed field gel electrophoresis (PFGE) patterns of Salmonella Enteritidis (S.Enteritidis) strains in Henan province.

METHODSS. Enteritidis strains were isolated from seven sentinel hospitals from March 2011 to December 2013. According to molecular typing and Salmonella (Kirby-Bauer, K-B) drug susceptibility testing method published by the international PulseNet bacterial infectious disease monitoring network and USA Clinical and Laboratory Standards Institute (CLSI), we analyzed drug sensitivity of 8 kinds antibiotics and PFGE molecule characteristics of 120 S. Enteritidis isolates from seven sentinel hospitals.

RESULTSAmong 120 strains of S. Enteritidis, 77 were isolated from male patients, 43 from female patients. A total of 78 strains S. Enteritidis were isolated from young children ranged from 0 to 5 years old (65.0%), including 57 strains isolated from 6 months to 2 years old (47.5%). The isolated time mainly centralized on May to October of the year, 11 strains isolated in March-April (9.2%), 48 were in May-July (40.0%),54 in August-October (45.0%), 7 in other months, with a typical summer seasonal characteristics. The resistance rate of 120 strains S. Enteritidis to ampicillin was 50.0% (n=60); to ceftazidime was 14.2% (n=17), to cefotaxime was 18.3% (n=22); to cefepime was 5.8% (n=7); to nalidixic acid was 61.7% (n=74); to ciprofloxacin was 8.3% (n=10), to norfloxacin was 5.8% (n=7); to gentamicin was 42.5% (n=51); to streptomycin was 21.7% (n=26); to chloramphenicol was 30.0% (n=36); resistance to methicillin benzyl ammonium was 11.7% (n=14), compound sulfamethoxazole resistance rate was 71.7% (n=86); the tetracycline resistant rate was 47.5% (n=57). All 120 strains of S. Enteritidis had different levels of resistance to 8 kinds of antibiotics, all strains were multidrug resistant strains, 28 isolates were resistant to 3-4 kinds of antibiotics (23.3%), 38 isolates were resistant to 5-6 kinds of antibiotics (31.7%), 39 isolates were resistant to 7-8 kinds of antibiotics (32.5%). All 120 strains of S. Enteritidis were divided into 44 molecular patterns by digestion with XbaI and pulsed field gel electrophoresis. each pattern contained 1-35 strains with similarity ranged from 54.3%-100%. EN14 and EN19 were the main PFGE types, including 35 and 29 strains respectively.

CONCLUSIONThe status of drug resistance of clinical isolates of Salmonella in Henan province was rather serious, PFGE patterns showed advantages and partial strain's corresponding resistant spectrum have certain relevance and the same aggregation relationship.

Anti-Bacterial Agents ; pharmacology ; Child, Preschool ; China ; Drug Resistance, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Microbial Sensitivity Tests ; Molecular Typing ; Salmonella Infections ; microbiology ; Salmonella enteritidis ; classification ; drug effects

Salmonella enterica Gallinarum (SG) causes fowl typhoid (FT), a septicemic disease in avian species. We constructed deletion mutants lacking the stress sigma factor RpoS, the nitric oxide (NO)-detoxifying flavohemoglobin Hmp, and the SsrA/SsrB regulator to confirm the functions of these factors in SG. All gene products were fully functional in wild-type (WT) SG whereas mutants harboring single mutations or a combination of rpoS, hmp, and ssrAB mutations showed hypersusceptibility to H2O2, loss of NO metabolism, and absence of Salmonella pathogenicity island (SPI)-2 expression, respectively. A triple-deletion mutant, SGDelta3 (SGDeltarpoSDeltahmpDeltassrAB), was evaluated for attenuated virulence and protection efficacy in two-week-old Lohmann layer chickens. The SGDelta3 mutant did not cause any mortality after inoculation with either 1 x 10(6) or 1 x 10(8) colony-forming units (CFUs) of bacteria. Significantly lower numbers of salmonellae were recovered from the liver and spleen of chickens inoculated with the SGDelta3 mutant compared to chickens inoculated with WT SG. Vaccination with the SGDelta3 mutant conferred complete protection against challenge with virulent SG on the chickens comparable to the group vaccinated with a conventional vaccine strain, SG9R. Overall, these results indicate that SGDelta3 could be a promising candidate for a live Salmonella vaccine against FT.
Administration, Oral ; Animals ; Bacterial Proteins/*genetics/immunology ; *Chickens ; Female ; Poultry Diseases/*immunology/microbiology ; Salmonella Infections, Animal/*immunology/microbiology ; Salmonella Vaccines/administration & dosage/genetics/*immunology ; Salmonella enterica/immunology/*physiology ; Vaccines, Attenuated/administration & dosage/genetics/immunology ; Virulence

Animals ; Environmental Microbiology ; Humans ; Malaysia ; Molecular Typing ; methods ; Salmonella Infections ; epidemiology ; microbiology ; Salmonella enterica ; classification ; genetics

Diarrhea ; epidemiology ; microbiology ; Humans ; Infant ; Salmonella Infections ; epidemiology ; microbiology ; Salmonella typhimurium