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

Outbreaks caused by highly industrialized food companies are characterized by cross-border, trans-regional, rapid and unpredictable, related to serious disease and economic burden. A cluster of cases with monophasic salmonella enterica serovar Typhimurium ST34 infection suspected to be associated with consumption of contaminated chocolate products have been reported in several Europe countries since December 2021. After retrospective investigations, the buttermilk circuit in the Belgian factory was suspected to be the point of origin of the contamination. This outbreak could provide a reference for the risk management of foodborne pathogens contamination in China. The objective of this paper was to summarize the process and characteristics of the outbreak of monophasic S. Typhimurium caused by contaminated chocolate products, analyze the characteristics of ST34 monophasic S. Typhimurium and the microbial management measures in the process of chocolate products, and systematically discuss the suggestions for the risk management of foodborne pathogens contamination and countermeasures for the rapid development of industrialization of food enterprises in China, in order to provide scientific and technological support for the prevention and control, prediction and early warning of sudden cases in China.
Humans ; Salmonella typhimurium ; Serogroup ; Salmonella Infections/prevention & control* ; Chocolate ; Retrospective Studies ; Salmonella enterica ; Disease Outbreaks/prevention & control* ; Risk Management

Aims: OpenPCR is a low cost yet accurate thermocycler which can be self-built. The aim of the study is to highlight a low-cost alternative method for rapid confirmation of five predominant non-typhoidal Salmonella (NTS) serotypes using a multiplex PCR on a portable-DIY OpenPCR© thermocycler. Methodology and results: Eight multiplex polymerase chain reaction (mPCR) samples containing genomic DNA of S. Agona selectively placed on the wells of the conventional PCR and OpenPCR© thermocyclers showed uniform heating in both thermocyclers. The limit of detection was similar for both thermocyclers for all five serotypes. The limit of detection for S. Typhimurium, S. Agona and S. Weltevreden was 10 pg/µL whereas the limit of detection for S. Enteriditis and S. Heidelberg was 1 pg/µL and 100 pg/µL, respectively. This assay incorporated a panel of unique genes; STM4495, SEN1392, SeHa-C4893, SeAg-B1096 and SENTW-3241 which were previously identified to be specific for S. Typhimurium, S. Enteritidis, S. Heidelberg, S. Agona, and S. Weltevreden, respectively, as well as the pan-Salmonella gene invA as internal control (IC) and pan-bacteria gene 16S rRNA to serve as amplification control (AC). The analytical specificity of the mPCR assay was found to be 100% for all five NTS using OpenPCR© thermocyclers. Conclusion, significance and impact of study The feasibility and low cost of the OpenPCR© thermocycler makes this device an ideal alternative for mPCR assay for rapid confirmation of NTS serotypes.
Salmonella Infections

Aims: The use of antimicrobial agent for treatment or growth promotion has added burden to treat infection diseases caused by pathogenic bacteria as they can acquire resistance. Salmonella is one of the major zoonotic bacterial pathogens that acts as a potential reservoir of antimicrobial resistance elements. In this study, the presence of Salmonella serotypes and the antibiogram patterns of the isolates from fecal samples of healthy cows in some selected localities in Eastern Cape, South Africa were studied. Methodology and results: Two hundred fecal samples were collected from healthy adult cows, of which 180 presumptive Salmonella isolates were recovered by conventional method. The isolates were identified using specific primer sets that are capable of detecting Salmonella spp. as well as delineating them into serogroups A, B, C1, C2, and D. Thereafter, antimicrobial susceptibility patterns of the identified isolates were determined by disk diffusion method against a panel of 12 antibiotics. From the molecular analysis of the isolates, 108 isolates were identified as Salmonella spp. and the confirmed isolates were further delineated into serogroup and the prevalence of the serogroups detected were 20%, 18%, 2%, 20% and 40% for serogroup A, B, C1, C2 and D respectively. Extremely high levels of antibiotic resistances were observed among the study isolates, while serogroup D was the most prevalent serogroup among the study isolates. Conclusion, significance and impact of study In conclusion, dairy cows could be considered as major reservoirs of antibiotic resistant Salmonella spp. that could be transmitted to humans via the food chain. This poses a significant public health risk especially to people living around the farms as well as those who consume poorly cooked meat and those who deal on raw cow meat.
Salmonella Infections, Animal

Salmonella enterica serovar Enteritidis (SE) is one of the most important zoonotic pathogens that cause enteritis and systemic infection in animals and human. Understanding invasive capacities of SE isolates is of vital importance to elucidate pathogenesis of Salmonella infection. To improve the throughput capacity and repeatability of classical gentamicin protection assay (GPA), a modified PGA was developed by taking high-throughput advantage of 96-well cell plates and multichannel pipettes. In addition, drop plate technique rather than spread plate method was applied in the modified GPA protocol for bacterial enumeration. The modified GPA protocol was evaluated by phenotyping intracellular replication of a high virulent and a low virulent SE isolates, JL228 and LN248, in a phagocytic cell line RAW264.7. The protocol was then applied in invasive phenotype determination of 16 SE strains to non-phagocytes (HT-29) and the intracellular replication of 43 SE strains to phagocytes (RAW264.7). Significant lower intra-group and inter-group coefficient of variations of the modified GPA was observed, implying good repeatability and reproducibility over traditional protocol. Further, replication phenotypes were also correlated with those from direct observation by confocal microscopy. Collectively, the improved GPA protocol had advantages of high throughput capacity, good repeatability and reliability, it was also noticed that the protocol also represented a fast and labor-saving alternative scheme for the invasive phenotype determination of Salmonella Enteritidis, and providing reliable phenotype profiles for Salmonella-host interplay interpretation.
Animals ; Gentamicins/pharmacology* ; Humans ; Phenotype ; Reproducibility of Results ; Salmonella Infections, Animal ; Salmonella enteritidis

We report the first case demonstrating an association between Kawasaki disease (KD) and erythema nodosum (EN). A 3-year-old girl presented with EN as an initial manifestation of KD. At the initial visit, she showed high fever of 40℃, injection of the oropharynx, cervical lymphadenopathy, and red-purple cutaneous nodules, particularly on the lower limbs. She complained of severe pain in the neck and cutaneous lesions. Initially, the development of EN was attributed to Salmonella spp infection, which was detected in stool culture. However, the patient did not respond to high-dose ampicillin/sulbactam to which the Salmonella spp is sensitive. Echocardiography performed as screening for fever of unknown origin revealed medium-sized aneurysms of the left anterior descending artery. EN masked the diagnosis of KD, and the patient developed a coronary artery lesion. KD should be considered in the differential diagnosis of refractory EN in pediatric patients.
Aneurysm ; Arteries ; Bacterial Infections ; Child, Preschool ; Coronary Vessels ; Diagnosis ; Diagnosis, Differential ; Echocardiography ; Erythema Nodosum ; Erythema ; Exanthema ; Female ; Fever ; Fever of Unknown Origin ; Humans ; Lower Extremity ; Lymphatic Diseases ; Masks ; Mass Screening ; Mucocutaneous Lymph Node Syndrome ; Neck ; Oropharynx ; Salmonella ; Skin ; Subcutaneous Tissue

Porcine proliferative enteropathy (PPE) caused by Lawsonia intracellularis (LI) is a global cause for substantial economic losses in the swine industry. Here, we constructed live attenuated Salmonella typhimurium (ST) mutant strains expressing and secreting 4 selected immunogenic LI antigens, namely, optA, optB, Lawsonia flagellin (LfliC), and Lawsonia hemolysin (Lhly); the resultant recombinant strains were designated Sal-optA, Sal-optB, Sal-LfliC, or Sal-Lhly, respectively. Using the BALB/c mouse model, we demonstrate that mice vaccinated once orally, either with a mixture of all 4 recombinant strains or with an individual recombinant strain, show significant (p < 0.05) production of LI-specific systemic immunoglobulin (Ig) G and mucosal IgA responses compared to the Salmonella alone group. Upon restimulation of vaccinated splenocytes with the LI-specific antigens, significant (p < 0.05) and comparable production of interferon-γ responses are found in all vaccinated groups, except the Sal-Lhly group, which shows non-significant levels. Challenge studies were performed in C57BL/6 vaccinated mice. On challenge with the LI (10(6.9) 50% tissue culture infectious dose) 14 days post-vaccination, 20% (1/5) of mice in all vaccinated groups, except Sal-Lhly group, show the presence of the LI-specific genomic DNA (gDNA) in stool samples. In contrast, 40% (2/5) and 60% (3/5) of mice vaccinated with the Sal-Lhly strain and the attenuated Salmonella alone, respectively, were found positive for the LI-specific gDNA. Furthermore, 0% mortality was observed in mice vaccinated against the ST challenge compared to the 30% mortality observed in the unvaccinated control group. In conclusion, we demonstrate that the Salmonella-based LI-vaccines induce LI-specific humoral and cell-mediated immunities, and encompass the potential to offer dual protection against PPE and salmonellosis.
Animals ; DNA ; Flagellin ; Immunity, Cellular ; Immunoglobulin A ; Immunoglobulins ; Lawsonia Bacteria ; Mice ; Mortality ; Salmonella Infections ; Salmonella typhimurium ; Salmonella ; Swine

OBJECTIVES: This study aimed to reveal the epidemiologic characteristics of the outbreak of gastroenteritis caused by Salmonella enterica serovar Thompson in Busan Metropolitan City and to identify points for improvement to prevent of food-borne disease outbreak. METHODS: This was a case-control study. The control group comprised asymptomatic students in the same classes of the cases. The presence or absence of symptoms, ingestion of each food provided by school meal service, and commonly ingested foods in addition to those foods in meal service were investigated. Moreover, specimens collected from rectal swab, preserved foods, and environmental surface were tested. RESULTS: Of the 6,092 subjects, 1,111 (1,083 students, 22 school personnel, and 6 foodservice employees) were included in the case group; this corresponded to an 18.4% attack rate. Symptoms included diarrhea (n=1,051, 94.6%), abdominal pain (n=931, 83.8%), febrile sensation (n=502, 45.2%), and vomiting (n=275, 24.8%). The epidemic curves of each 10 schools were unimodal. Investigation of food intake showed a significantly high odds ratio for chocolate cake in 5 out of the 10 schools. Laboratory test detected Salmonella enterica serovar Thompson both in rectal swab specimens of 9 schools and in collected preserved chocolate cakes of 9 schools. Pulsed-field gel electrophoresis test result showed that Salmonella enterica seorvar Thompson isolated from human and foods were the same. CONCLUSIONS: The source of infection for the Salmonella enterica serovar Thompson outbreak in the 10 schools of Busan Metropolitan City is chocolate cake. Traceback investigation for origin of contaminated food in food-borne disease outbreak and safety control during food production should be more enhanced.
Abdominal Pain ; Busan ; Cacao ; Case-Control Studies ; Diarrhea ; Eating ; Electrophoresis, Gel, Pulsed-Field ; Food, Preserved ; Foodborne Diseases ; Gastroenteritis ; Humans ; Korea ; Meals ; Odds Ratio ; Salmonella enterica ; Salmonella Infections ; Salmonella ; Sensation ; Serogroup ; Vomiting

OBJECTIVES: This study aimed to reveal the epidemiologic characteristics of the outbreak of gastroenteritis caused by Salmonella enterica serovar Thompson in Busan Metropolitan City and to identify points for improvement to prevent of food-borne disease outbreak.METHODS: This was a case-control study. The control group comprised asymptomatic students in the same classes of the cases. The presence or absence of symptoms, ingestion of each food provided by school meal service, and commonly ingested foods in addition to those foods in meal service were investigated. Moreover, specimens collected from rectal swab, preserved foods, and environmental surface were tested.RESULTS: Of the 6,092 subjects, 1,111 (1,083 students, 22 school personnel, and 6 foodservice employees) were included in the case group; this corresponded to an 18.4% attack rate. Symptoms included diarrhea (n=1,051, 94.6%), abdominal pain (n=931, 83.8%), febrile sensation (n=502, 45.2%), and vomiting (n=275, 24.8%). The epidemic curves of each 10 schools were unimodal. Investigation of food intake showed a significantly high odds ratio for chocolate cake in 5 out of the 10 schools. Laboratory test detected Salmonella enterica serovar Thompson both in rectal swab specimens of 9 schools and in collected preserved chocolate cakes of 9 schools. Pulsed-field gel electrophoresis test result showed that Salmonella enterica seorvar Thompson isolated from human and foods were the same.CONCLUSIONS: The source of infection for the Salmonella enterica serovar Thompson outbreak in the 10 schools of Busan Metropolitan City is chocolate cake. Traceback investigation for origin of contaminated food in food-borne disease outbreak and safety control during food production should be more enhanced.
Abdominal Pain ; Busan ; Cacao ; Case-Control Studies ; Diarrhea ; Eating ; Electrophoresis, Gel, Pulsed-Field ; Food, Preserved ; Foodborne Diseases ; Gastroenteritis ; Humans ; Korea ; Meals ; Odds Ratio ; Salmonella enterica ; Salmonella Infections ; Salmonella ; Sensation ; Serogroup ; Vomiting

Acute myocarditis is clinically rare in children, but poses a significant risk for morbidity and mortality. Children with myocarditis show a wide variety of clinical manifestations ranging from subclinical myocarditis to heart failure, hemodynamic compromise, arrhythmia, and even sudden death. Salmonella species are associated with clinical presentations including gastroenteritis, enteric fever, bacteremia, and extra-intestinal focal infections. Non-typhoidal Salmonella infections usually cause self-limiting gastroenteritis, but are rarely associated with myocarditis. In this report, we present a case of myocarditis associated with Salmonella serogroup B gastroenteritis in a previously healthy 15-year-old boy.
Adolescent ; Arrhythmias, Cardiac ; Bacteremia ; Child ; Death, Sudden ; Focal Infection ; Gastroenteritis ; Heart Failure ; Hemodynamics ; Humans ; Magnetic Resonance Imaging ; Male ; Mortality ; Myocarditis ; Salmonella Infections ; Salmonella ; Serogroup ; Typhoid Fever